Understanding the variations in root canal morphology is important for successful endodontic treatment. Mandibular first premolars have a single root in 98% of cases, and multiple root canals are found in approximately 20% of cases. However, the details of these characteristic findings in panoramic radiography and their diagnostic accuracy are unknown. This study aimed to investigate the characteristic radiographic findings of mandibular first premolars possessing multiple root canals and determine the diagnostic accuracy using panoramic radiography. Four radiologists evaluated 347 mandibular first premolars in 186 patients who underwent panoramic radiography and dental cone beam computed tomography (CBCT). Two radiologists confirmed the existence of single or multiple root canals using CBCT. The remaining two radiologists evaluated the imaging findings of the root canal morphology and classified them into two patterns: gradual narrowing and sudden narrowing. In the case of the sudden narrowing pattern, the location of sudden narrowing was also evaluated. A gradual narrowing pattern was observed in 56% of teeth with a single root canal, and a sudden narrowing pattern was observed in 83% of teeth with multiple root canals. When sudden narrowing between the cervical and apical 1/4 of the root canal was used as the diagnostic criterion for multiple root canal teeth, the highest diagnostic performance was observed (sensitivity, 76.1%; specificity, 73.9%). The sudden narrowing between the cervical level and the apical 1/4 level of the root canal is a practical diagnostic criterion for mandibular first premolar with multiple root canals.

OBJECTIVES: Oral bacteria may contribute to postoperative infectious complications including postoperative pneumonia or surgical site infection. The aim of this study was to investigate the impact of preoperative dental care on postoperative outcomes among surgical patients under general anesthesia. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: We analyzed clinical records of major surgical patients at a university hospital between 2016 and 2018. Subjects were categorized into either the preoperative dental care group, those being referred to dentists by their surgeons based on an individual surgeon's judgment for dental care before surgery, or the control group. METHODS: The primary outcome was postoperative infectious complications. Secondary outcomes were postoperative inflammation markers (C-reactive protein and fever), and economic outcomes (postoperative length of hospital stay and medical expenses). As the main analysis, the average treatment effects of the preoperative dental care were obtained from the augmented inverse-probability weighting (AIPW) method with consideration of demographics and perioperative risk factors to estimate causal effect of the intervention from the observational data. Then, stratified analyses by age and surgical sites were conducted with the inverse-probability weighting and linear regression methods, respectively. RESULTS: In the AIPW estimation, compared with the control group, the care group saw a significantly lower rate of postoperative infection (average treatment effect -3.02) and shorter fever duration (-2.79 days). The stratified analysis by age revealed significant positive impact of dental care in all age groups, including the highest treatment effects observed among patients younger than 60. Also, treatment effect was observed in wider surgical sites than previously known. CONCLUSION/IMPLICATIONS: This study indicates a significant impact of preoperative dental care on preventing postoperative infection and inflammation. Along with old age or certain types of surgeries in which advantages of dental referral have been already known, preoperative dental referral could be beneficial for broader types of patients.

The aim of this study was to assess the utility of an actuator-driven pulsed water jet (ADPJ) as a hardness-dependent carious dentin removal device by using different outputs. Thirty-six plane surface dental caries samples were treated with the ADPJ at 150, 200, and 250 voltage (12 teeth each). The Knoop hardness number (KHN) and Ca/P mass ratio were measured at 70 μm from the deepest point of the removing groove. Furthermore, three other teeth samples were manually treated with the ADPJ at the three above mentioned voltages (one tooth each) for 1 min. The KHN and Ca/P mass ratio were measured at 70 μm from the surface of the residual dentin part. In both the KHN and Ca/P mass ratio, higher residual dentin depended on the applied voltage of ADPJ. The ADPJ enabled the removal of softened carious dentin in an applied voltage-dependent manner.

A perfusion defect (PD) in non-enlarged lymph nodes (LNs) of oral squamous cell carcinoma (OSCC) is the most reliable radiological criterion for the diagnosis of metastasis. However, conventional contrast-enhanced (CE) T1 weighted images using turbo spin echo (TSE) sequence is limited in detecting PD in non-enlarged LNs due to flow artifacts from cervical blood vessels. Vessel wall (VW) MR imaging with blood vessel flow suppression and high spatial resolution may provide new insights into the detection of PD. However, there are no reports in the literature on the usefulness of VW MR imaging for the diagnosis of LN metastasis. It is demonstrated that PD of non-enlarged LNs in CE VR MR imaging of OSCC patients is useful for the diagnosis of metastatic LNs. VW MR imaging was significantly more sensitive in detecting PD of non-enlarged metastatic LNs than conventional TSE imaging on visual evaluation. Furthermore, it was found that the image contrast between PD and surrounding intranodal tissue in CE VW MR images was higher than that in conventional CE TSE images. In the correlation between imaging and histopathological findings of metastatic LNs, all LNs that exhibited PD on CE VW MR images were at an advanced histopathological metastatic stage. The pathology of PD was necrotic tissue with keratinization. The results indicated that PD in CE VW imaging is useful in diagnosing non-enlarged LNs at an advanced metastasis stage. The addition of VW MR imaging to conventional MR examination achieves higher diagnostic performance for non-enlarged metastatic LNs.

OBJECTIVE: The higher sensitivity of the new-generation positron emission tomography/computed tomography (PET/CT) with silicon photomultiplier (SiPM) may increase false-positive rates in detecting metastatic lymph nodes (LNs). This study aimed to clarify the usefulness of the SiPM PET scanner in diagnosing LN metastasis of oral squamous cell carcinoma (SCC). METHODS: We retrospectively reviewed consecutive F-18 fluorodeoxyglucose PET/CT images of 39 SCC patients using SiPM PET and 31 SCC patients using non-SiPM PET. We measured the maximum standardized uptake value (SUVmax) of the LNs on PET images and maximum short-axis diameter on transverse CT images. RESULTS: The sensitivity and specificity of SiPM PET were 86.2% and 95.6%, respectively (cut-off SUVmax, 4.6). The area under the curve (AUC) of SiPM PET (0.977; 95% confidence interval [CI], 0.958-0.995) was significantly higher than that of non-SiPM PET (0.825; 95% CI 0.717-0.934) (P < 0.01). In a size-limited analysis of diameter, the AUC of SiPM PET (≥ 0.96 for all diameters) was significantly higher than that of non-SiPM PET (tended to decrease as the LN diameter decreased) for the diagnosis of LN metastasis by SUVmax. CONCLUSION: SiPM PET had higher diagnostic accuracy for LN metastasis of oral SCC than non-SiPM PET, even for small LN metastasis without increasing false-positives.

BACKGROUND: Skeletal mandibular protrusion would influence to the muscle fatigue of the masticatory muscles. Establishing a diagnostic procedures combining physiological and biochemical information is necessary for quantitative evaluation of masticatory muscle fatigue. OBJECTIVE: The transverse relaxation time (T2 time) of muscle functional magnetic resonance imaging (mfMRI), and 31 P-magnetic resonance spectroscopy (MRS) were used to investigate the reliability as parameters for measuring the masseter muscle in patients with skeletal mandibular prognathism. METHOD: The subjects were 19 patients diagnosed as skeletal mandibular protrusions and 19 healthy subjects as a control group. Transverse relaxation time (T2 value) determined by mfMRI along with creatine phosphate (PCr) and inorganic phosphorus (Pi) determined by 31 P-MRS before, during, and after clenching were used for molecular imaging of muscle fatigue. RESULTS: The average T2 value of the patient group was significantly higher than that of the healthy control group at rest. Furthermore, the average T2 value transiently increased in both groups during experimental clenching. The PCr and Pi showed a tendency toward a transient decrease and increases, respectively. The pH in the masseter muscle showed a transient decrease in both groups prior to and following experimental clenching. The pH in the masseter muscle of the patient group was significantly lower than that in the healthy control group at rest and recovery. CONCLUSION: We showed mfMRI and 31 P-MRS are useful for evaluating masseter fatigue during clenching, and the masseter muscle in the prognathic patients showed more severe fatigue than the healthy controls.

PATIENT: A 33-year-old man diagnosed with extranodal natural killer cell/T-cell lymphoma, nasal type (ENKTCL-NT) inducing palatal perforation was referred to the perioperative oral care support center of Tohoku University Hospital for dental care to support cancer treatment including chemotherapy and hematopoietic stem cell transplantation (HSCT). Dental review during chemotherapy revealed mucositis suspected to be caused by mucosal trauma from altered jaw function (chewing and speech) due to palatal perforation. Although the patient was already in the cleanroom, an oral appliance as well as conservative care as recommended in oral management guidelines for HSCT were used to prevent worsening of oral mucositis at subsequent HSCT including High-dose chemotherapy and total body irradiation. After HSCT, a prosthodontist fitted a palatal obturator made by a dental technician and an oral surgeon reviewed the necrotic bone and removed the sequestra according to the changes in the palate. This approach involving a multidisciplinary team including a hematologist improved the impaired oral function and minimized oral complications . DISCUSSION: ENKTCL-NT and its treatment have a significant impact on patients' oral status. Hence, it is important to provide customized dental care based on previously endorsed guidelines according to the type of disease, treatment requirements, and oral and systemic status. CONCLUSIONS: This report indicated the importance of dental care with a customized plan before, during, and after HSCT for ENKTCL-NT with multidisciplinary supportive care for cancer patients to improve the impaired oral function and to minimize oral complications.

OBJECTIVES: The most typical maxillofacial feature of patients with acromegaly is mandibular protrusion. This study aimed to determine differences in maxillofacial morphology between skeletal Class III patients with and without acromegaly using cephalometric analysis. METHODS: Cephalograms of 37 patients with acromegaly (Acro), 37 age-matched non-acromegalic patients with skeletal Class III malocclusion (C-III), and 37 age-matched Class I malocclusion patients (C-I; control) were retrospectively collected. The skeletal and dental morphology of each group was analyzed using cephalometric analysis, which included linear and angular measurements and facial profilograms. In addition, we analyzed diagnostic performance and cutoff values for discriminating acromegaly from skeletal Class III malocclusion using receiver operating characteristic (ROC) curve analysis. RESULTS: The mandibular ramus height was larger in the Acro group than in the other groups. The increase in L1/MP in the Acro group, which represented labial inclination of the mandibular central incisors, was the most characteristic feature in this study. ROC curve analysis indicated that a cutoff value of 88.4° for L1/MP had the highest diagnostic performance in discriminating acromegaly from non-acromegalic Class III malocclusion. CONCLUSIONS: Acromegaly was characterized by a greater degree of bimaxillary prognathism than was non-acromegalic Class III malocclusion. Focusing on labial inclination of the mandibular central incisors would be the most useful way to differentiate acromegaly from non-acromegalic Class III malocclusion.

ABSTRACT: The purpose of the present study was to investigate the efficacy of perioperative oral managements (POMs) on perioperative nutritional conditions in patients undergoing surgery with general anesthesia. Medical records were retrospectively reviewed and the effects of POMs were investigated based on a large number of cases using a multicenter analysis. The profile of serum albumin levels was assessed and compared between patients with and without POMs using the multivariate analysis. Seventeen Eleven thousand and one hundred sixty patients (4,873 males and 6,287 females) were reviewed. Of these, 2710 patients (24.3%) had undergone POMs. The results of a multivariate analysis revealed the significant positive effect of POMs on perioperative serum albumin level (change between at admission and discharge, (Estimate: 0.022, standard error: 0.012, P < .0001). Patient gender, age, surgical site, performance status, the American Society of Anesthesiologists (ASA) physical status classification, operation time, amount of blood loss, and serum albumin level at admission were also significant predictors. Adjusted multivariate analysis of the effects of POMs on perioperative change of serum albumin level in all subjects reveled the significance of POMs intervention (estimate: 0.022, standard error: 0.012, P < .0001). These results suggest that POMs exerts significant positive effects on perioperative serum albumin levels in patients underwent surgery under general anesthesia.

We investigated the sensitivities of 2-dimensional (2D) magnetic resonance sialography (MR-S) and unilateral sagittal and axial 3-dimensional (3D) MR-S using a surface coil and their combination in diagnosing patients with Sjögren's syndrome (SS). We retrospectively analyzed the 3D and 2D MR-S results of 78 patients with SS. We evaluated the sensitivities of multiple high-signal-intensity spots and staging on MR sialograms and analyzed the efficient imaging methods and cross section for diagnosing patients with SS. The sensitivities of MR-S for detecting abnormal findings (i.e., MR-S stage 1 or higher) were as follows: 65 cases (83.3% [95% confidence interval (CI): 73.2-90.8]) for unilateral sagittal 3D MR-S; 62 cases (79.4% [95% CI: 68.8-87.8]) for axial 3D MR-S; 66 cases (84.6% [95% CI: 74.7-91.8]) for combined unilateral sagittal and axial 3D MR-S; and 32 cases (41.0% [95% CI: 30.0-52.7]) for bilateral sagittal 2D MR-S. The ratio of the abnormal finding of MR-S was tested using the two-tailed Fisher's exact test. Unilateral sagittal, axial, and combined unilateral sagittal and axial 3D MR-S showed significantly higher sensitivity than bilateral sagittal 2D MR-S, respectively (P < 0.001). Most cases upstaged by 3D MR-S were those positive (stage 1 or higher) among the stage 0 cases detected by 2D MR-S. Axial 3D MR-S, compared with 2D MR-S, understaged four cases, which was due to the imaging range of the axial 3D MR-S. We concluded that a single unilateral sagittal 3D MR-S was sufficient and axial 3D MR-S was unnecessary for SS staging. T1- and T2-weighted images are essential for investigating the salivary glands in patients with SS. Therefore, we also concluded that bilateral sagittal 3D MR-S of the parotid glands in addition to T1- and T2-weighted imaging is necessary, sufficient, and most efficient for precise MR imaging examination of the salivary glands, including diagnosing SS.

© 2021 Japanese Stomatological Society Introduction: A squamous cell carcinoma of the oral cavity or mobile tongue represents the sixth most common type of cancer worldwide. Patient work-up procedures vary among institutions, though generally include clinical, imaging, and histopathology examinations. This study had two aims: assess the accuracy of ultrasound (US) and magnetic resonance imaging (MRI) for evaluating tumor thickness of ventral tongue squamous cell carcinoma, and ascertain the effects of biopsy on imaging results. Methods: We retrospectively examined the medical records of 69 patients diagnosed and treated for ventral tongue squamous cell carcinoma stage T1 or T2. We compared tumor thickness in US and MRI results with histological thickness measured using specimens obtained in a partial glossectomy. Results: The mean difference between thickness measured with MRI before the biopsy procedure and that of the pathological specimens was 0.28 mm while that between US imaging results before the biopsy and histologic thickness was 0.75 mm. Furthermore, following the biopsy, the mean difference between thickness shown by MRI and that of the histological specimens was 0.89 mm, and between US findings and histologic thickness was 2.67 mm. There was a positive correlation between thickness shown by MRI and US when performed before the biopsy and the pathological result. Conclusions: MRI and US results appear to have adequate accuracy for estimating the thickness of T1-and T2 lesions of the tongue when scanning is performed prior to a biopsy procedure. Furthermore, the present findings confirm the clinical impression that inflammatory changes induced by a biopsy often alter later imaging findings.

A simple bone cyst (SBC) is an intrabone cavity without epithelial lining, which occasionally occur with fibrous-osseous lesions. The imaging finding of the scalloped border and conserving the lamina dura, periodontal ligament spaces, or follicular spaces are considered radiographically pathognomonic of SBC. SBC has been reported to occur with fibrous-osseous lesions, including cemento-osseous dysplasia (COD). Computed tomography (CT) imaging findings are sparse, and there are no reports of magnetic resonance imaging (MRI) findings, including apparent diffusion coefficient (ADC) value calculated by diffusion-weighted MRI for the florid COD-associated SBC. We report a case of a 39-year-old woman who was referred to our hospital because a panoramic radiograph of her right mandible showed asymptomatic radiolucency in the apical molar area. CT images showed a low-density lesion in the periapical areas of the right mandible, which accompanied a well-defined, high-density lesion, and a mixed low/high-density lesion with an unusual marked irregular border in the left mandible. The MRI showed cyst-like extremely hyperintense signals on fat-suppressed T2-weighted images at the right mandibular low-density and the left mandibular mixed low/high-density areas. ADC map showed high values (over <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn>2.5</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math> mm²/s) at the cystic areas in the bilateral mandible. We performed incisional biopsies of the bilateral mandibular lesions and resections of the bilateral maxillary lesions. Surgical and histopathological findings established a diagnosis of florid COD in the bilateral mandible and maxilla, simultaneously complicated by multiple SBCs in the bilateral mandible. The ADC value of cystic component is useful for the diagnosis, if the COD-associated SBC exhibits solitary, nonspecific, or rare imaging findings.

BACKGROUND: The impact of the jaw bone condition, such as bone quantity and quality in the implant placement site, affecting the accuracy of implant placement with computer-guided surgery (CGS) remains unclear. Therefore, this study aimed to evaluate the influence of bone condition, i.e., bone density, bone width, and cortical bone thickness at the crestal bone on the accuracy of implant placement with CGS. METHODS: A total of 47 tissue-level implants from 25 patients placed in the posterior mandibular area were studied. Implant placement position was planned on the simulation software, Simplant® Pro 16, by superimposing preoperative computed tomography images with stereolithography data of diagnostic wax-up on the dental cast. Implant placement surgery was performed using the surgical guide plate to reflect the planned implant position. The post-surgical dental cast was scanned to determine the position of the placed implant. Linear and vertical deviations between planned and placed implants were calculated. Deviations at both platform and apical of the implant were measured in the bucco-lingual and mesio-distal directions. Intra- and inter-observer variabilities were calculated to ensure measurement reliability. Multiple linear regression analysis was employed to investigate the effect of the bone condition, such as density, width, and cortical bone thickness at the implant site area, on the accuracy of implant placement (α = 0.05). RESULT: Intra- and inter-observer variabilities of these measurements showed excellent agreement (intra class correlation coefficient ± 0.90). Bone condition significantly influenced the accuracy of implant placement using CGS (p < 0.05). Both bone density and width were found to be significant predictors. CONCLUSIONS: Low bone density and/or narrow bucco-lingual width near the alveolar bone crest in the implant placement site might be a risk factor influencing the accuracy of implant placement with CGS.

総合病院で入院加療を行った患者を対象に、口腔機能の現状や歯科医療ニーズに関する全国調査を実施した。2017年11月1日から11月30日もしくは2018年1月1日から1月31日の1ヵ月間に日本口腔科学会研修施設で入院加療を行った患者を対象に質問紙法を実施した。26医療機関より2280件(男性1223人、女性1057人、平均57.3歳)の回答を得た。口腔内に何らかの自覚症状をもつと回答した患者は1647人(72.2%)、なしと回答した患者は202人(8.9%)であった。口腔症状の内訳は口腔乾燥が370人(16.2%)、歯肉の疼痛・出血などの歯周炎が246人(10.8%)、義歯不適合169人(7.4%)などであった。入院中に口腔内の自覚症状が改善したと答えた患者は291人(12.8%)、悪化したと答えた患者は129人(5.7%)、変化なしと答えた患者は1705人(74.8%)であった。入院中に院内の歯科・口腔外科・口腔ケア外来等の歯科部門を受診した患者は415人(18.2%)にとどまっていた。入院中に主科で受けた治療内容と口腔症状の変化、口腔症状と食事形態に関する患者の意識を比較したところ、放射線治療を受けた患者に口腔症状の悪化を感じているものが多いことが判明した。

BACKGROUND: While hand and ultrasonic scalers are the primary tools used for the removal of dental calculus in periodontal treatment, many studies have shown that they also damage the enamel surface. We have developed a novel actuator-driven pulsed water jet (ADPJ) system, which has the ability to selectively remove materials depending on their stiffness. Considering the different material properties between teeth and dental calculus, it might be possible to develop the ADPJ to remove dental calculus without damage to the tooth's enamel surface using a suitable jet pressure. Therefore, the aim of this study was to assess the effectiveness of the ADPJ in removing dental calculus, and the surface features of the teeth after its use. METHODS: A total of 93 artificial teeth coated with artificial dental calculus were examined in this study. The weights of 90 teeth were measured before and after the use of ADPJ, which had an applied voltage setting of 150, 200, or 240 V. The three remaining teeth were instrumented with a conventional hand scaler, ultrasonic scaler, or ADPJ (set at 240 V). Damage to the artificial tooth surfaces was evaluated using 5% Evans blue dye under an optical microscope. Furthermore, apatite pellets, which are utilized as experimental substitutes for natural teeth, were assessed after the use of ADPJ and both conventional scalers. RESULTS: The ADPJ significantly reduced the amount of artificial calculus, and the removal rate was dependent on the applied voltage. No damage was observed on the surface of the artificial tooth and apatite pellet following the use of ADPJ, in contrast to the conventional scalers. CONCLUSIONS: The results of this study demonstrate the in vitro effectiveness of ADPJ in the removal of dental calculus, without causing damage to tooth surfaces.

OBJECTIVE: We assessedthe etiology of idiopathic condylar resorptionby examining the effects of oestrogen and compressive mechanical stress under a low systemic oestrogen condition in temporomandibular joints (TMJ) caused by an ovariectomy. MATERIALS AND METHODS: Female rabbits were divided into non-ovariectomy (non-OVX) and ovariectomy (OVX) groups. A cortical osteotomy was performed witha custom device that wasincreased in length by 0.25 mm every 12 hoursfor 1 week after the operation,during which the TMJsin the rabbits received compressive mechanical stress. Samples from both groups were examined with micro-computed tomography and histological staining. RESULTS: Area and depth of bone resorption were both greaterin the OVX group.Furthermore, a significantly earlier and greater prevalence of sub-condylar bone resorptionwasnoted in that group, while cells positive fortartrate-resistant acid phosphatase were increased in the OVXgroup. CONCLUSIONS: The present findings suggest that oestrogeninduced a much greater amount of bone resorption on the anterior surfaceof the condylar headat an earlier stage in the TMJs of the present model rabbits. Thereafter, restoration of TMJ function appeared to occur in a normal manner.

Effect of octacalcium phosphate/gelatin composite (OCP/Gel) on angiogenesis was studied by its implantation in rat calvaria critical-sized defect in relation to bone regeneration for 2 and 4 weeks. The implantation of OCP/Gel disks was analyzed by radiomorphometry using a radiopaque material perfusion (Microfil®) method and histomorphometry by hematoxylin and eosin-staining before and after the decalcification. Effect of the OCP dose in the range up to 4 mg per well on the capillary-like tube formation by human umbilical vein endothelial cells (HUVECs) was also examined in a transwell cell culture. The results showed that the blood vessels formation by OCP/Gel group was significantly higher at 2 weeks than other groups but decreased at 4 weeks during the advancement of new bone formation. The capillary-like tube formation was highest in an OCP dose of 1 mg per well while other OCP doses above or below 1 mg did not show such a stimulatory effect. The results established both in vivo and in vitro confirmed that OCP has a positive effect on angiogenesis during bone regeneration in a suitable dose ranges, suggesting that the angiogenesis stimulated by OCP could be involved in the OCP/Gel-enhanced bone regeneration. STATEMENT OF SIGNIFICANCE: We have reported that octacalcium phosphate (OCP) materials display stimulatory capacities on the bone tissue-related cells. However, the effect of OCP on the angiogenesis and its relation to the OCP-enhanced bone regeneration is unknown. This study confirmed the capacity of OCP on angiogenesis before increasing the new bone mass after the implantation of a composite of OCP and gelatin (OCP/Gel). The blood vessels formation took place associated with the area beginning of the new bone formation, which finally decreased together with development of bone formation. Because OCP was ascertained stimulating the capillary-like tube formation in HUVEC culture with a certain OCP dose, the present study is the first report showing the capacity of OCP on angiogenesis during the OCP/Gel-enhanced bone regeneration.

© 2019, Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd. Objectives: To ascertain the effects of exposure parameters (tube current and tube voltage) and the gutta-percha cone (GPC) size on root fracture-like artifacts obtained with cone-beam computed tomography (CBCT). Methods: Fracture-like artifacts appearing on CBCT images of nine extracted human mandibular premolars filled with GPCs of size #50 or #80 were analyzed using six exposure factors: two tube voltages (80 kV and 110 kV); and three tube currents (4 mA, 7 mA, and 10 mA). On axial images, the gray value (GV) was recorded at three points: the mesiobuccal portion (MBP) as the sound dentin, the mesial portion (MP) as the artifact line, and the water area (WA). The rate of decrease in the GV (RDGV) of the artifact line was calculated using the formula: RDGV (%) = (GV of MBP − GV of MP) × 100/(GV of MBP − GV of WA). Results: Comparison of the #80 group and the #50 group with equal tube voltages and tube currents shows that artifact lines in the #80 group were more obvious than those in the #50 group. The artifact lines with 80 kV were markedly more visible than those with 110 kV for each tube current and GPC size. Tube current changes did not affect the artifact line for any tube voltage or GPC size. Conclusions: For the reduction of artifacts, we recommend selection of higher tube voltages and lower tube currents when taking CBCT images of teeth with each GPC size.

ObjectiveWe experimentally compared the effects of compressive and tractional mechanical stress on the temporomandibular joint (TMJ) of rabbits to assess the etiology of progressive condylar resorption. Materials and MethodsWe performed a cortical osteotomy using custom-made devices that were lengthened by 0.25mm every 12h for 1week after surgery. During this time, the rabbit TMJ was under compressive or tractional mechanical stress. The samples in each group were examined using micro-computed tomography and histological staining. ResultsScores for the area of bone resorption were higher in the compressive group than in the tractional group. Moreover, scores for the depth of bone resorption were higher in the compressive group than those in the tractional group. We observed a significantly higher prevalence of resorption in the subcondylar bone in the compressive group than in the tractional group. There were substantially more cells that were positive for tartrate-resistant acid phosphatase in the compressive group than in the control and tractional groups. ConclusionsThe outcomes here suggest that excessive mechanical stress, particularly compressive mechanical stress, may significantly affect morphological bone change findings in the TMJ.

近年のインプラント治療患者数は増加傾向にあり、安全で専門性の高いインプラント医療へのニーズは高まっている。これより2013年4月、東北大学病院にインプラント治療に関わる複数の専門分野を集約する体制で歯科インプラントセンターが開設された。今回われわれは2013年4月1日から2014年3月31日まで開設1年間の歯科インプラントセンターで行ったインプラント処置の臨床統計を報告する。2014年4月1日から2014年3月31日にかけて当センターでインプラント前処置の骨増生術を含んだインプラント処置行った症例、患者数、処置本数、埋入部位、併用した麻酔方法、骨増生症例数、保険インプラント数さらに最終補綴装置について調査した。調査した1年間でのインプラント処置総症例数は、168症例であった。平均年齢53.9歳±3.5で60歳代が最も多かった。インプラント体の総埋入本数は合計277本であった。埋入部位としては下顎臼歯部が142本であった。併用した麻酔法に関しては局所麻酔下処置が118症例238本であった。骨増生術を施行した38症例であった。広範囲顎骨支持型補綴装置は5症例16本行った。最終補綴装置を装着した74症例に対し、固定性上部構造は62症例で、オーバーデンチャータイプは、14症例であった。歯科インプラントセンターの開設はインプラント治療の増加をもたらしたが、長期的治療を必要とするインプラント治療において安全で予知性の高い治療を確実に行うためにも、よりいっそうの関連各科との連係を深め治療カンファレンスを充実したものにする必要がある。(著者抄録)

がんの化学療法や放射線療法では口腔粘膜炎をはじめとする口腔内症状を引き起す場合が多く、頭頸部の手術では口腔管理を行うことで創部治癒の感染防ぎ入院期間の短縮に繋がることが報告された。このように周術期の口腔管理の重要性が認識され、2012年度より、がん治療や心臓血管手術を必要とした患者に対する周術期口腔機能管理が保険導入された。本報告では、東北大学病院での周術期口腔管理の受診動向を調査した。東北大学病院では、2015年4月に周術期口腔支援センターを設置し、周術期患者の歯科的対応窓口として機能している。開設から2年弱が経過した時点までの周術期口腔支援センター受診の初診患者を対象とし、初診時の紹介状の内容と周術期口腔管理に関する要望の動向を調査した。紹介元診療科としては、歯科口腔外科、心臓血管外科、移植・再建・内視鏡外科、耳鼻咽喉・頭頸部外科、血液・免疫科、循環器内科の順で多く、この傾向はこの2年間変わらなかった。全体では、放射線治療前、化学療法前、ビスホスフォネート(BP)製剤・抗RANKL抗体製剤の使用前の紹介が増加していた。周術期口腔支援センターへの患者紹介の動向の変化は、医科による歯科の重要性の認識の高まりによるものと考えられた。本センターの設置を通し、医科歯科連携をより強固に、そして多くの患者の助けとなることが考えられ、更に周術期口腔支援を推進する必要がある。(著者抄録)

近年のインプラント治療患者数は増加傾向にあり、安全で専門性の高いインプラント医療へのニーズは高まっている。これより2013年4月、東北大学病院にインプラント治療に関わる複数の専門分野を集約する体制で歯科インプラントセンターが開設された。今回われわれは2013年4月1日から2014年3月31日まで開設1年間の歯科インプラントセンターで行ったインプラント処置の臨床統計を報告する。2014年4月1日から2014年3月31日にかけて当センターでインプラント前処置の骨増生術を含んだインプラント処置行った症例、患者数、処置本数、埋入部位、併用した麻酔方法、骨増生症例数、保険インプラント数さらに最終補綴装置について調査した。調査した1年間でのインプラント処置総症例数は、168症例であった。平均年齢53.9歳±3.5で60歳代が最も多かった。インプラント体の総埋入本数は合計277本であった。埋入部位としては下顎臼歯部が142本であった。併用した麻酔法に関しては局所麻酔下処置が118症例238本であった。骨増生術を施行した38症例であった。広範囲顎骨支持型補綴装置は5症例16本行った。最終補綴装置を装着した74症例に対し、固定性上部構造は62症例で、オーバーデンチャータイプは、14症例であった。歯科インプラントセンターの開設はインプラント治療の増加をもたらしたが、長期的治療を必要とするインプラント治療において安全で予知性の高い治療を確実に行うためにも、よりいっそうの関連各科との連係を深め治療カンファレンスを充実したものにする必要がある。(著者抄録)

© 2016 John Wiley &amp; Sons A/S. Published by John Wiley &amp; Sons Ltd Objective: We analyzed the diagnostic performance of the MR imaging findings of the parotid, submandibular, and sublingual glands to discriminate between patients with and without Sjögren&#039;s syndrome. Methods: We retrospectively analyzed the correlation between the MR imaging and histopathological findings obtained from 69 patients with clinically suspected Sjögren&#039;s syndrome. We evaluated the heterogeneous signal intensity distribution on T1- and T2-weighted images, the multiple high-signal-intensity spots on MR sialograms, and the volume of the parotid, submandibular, and sublingual salivary glands. Results: The multiple high-signal-intensity spots in the parotid gland showed the highest sensitivity and diagnostic accuracy (82% and 83%, respectively). In addition, the multiple high-signal-intensity spots and the heterogeneous signal intensity distribution in the submandibular gland showed high specificity (100% and 88%, respectively). The volume of the submandibular gland, but not that of the parotid or sublingual gland, was smaller in patients with Sjögren&#039;s syndrome. Conclusions: The presence of multiple high-signal-intensity spots on an MR sialogram in the parotid gland should be considered the best diagnostic indicator for Sjögren&#039;s syndrome. The presence of spots, heterogeneity, and the change to smaller volumes in the submandibular gland were also helpful because of their high specificity, particularly in advanced cases.

<p>われわれは，う蝕を客観的に評価して，障害のある人に確実な診断と治療を行うために，う蝕の診断に超音波顕微鏡が応用可能かどうかを検討した．</p><p>本研究には，隣接面に限局するう窩を有する10本の抜去智歯を用いた．デンタルエックス線写真を撮影後に，各歯は矢状面で500<i>μ</i>mの厚さに薄切し，う窩を超音波顕微鏡で観察した．超音波顕微鏡で得られた画像にてマクロ画像においてう蝕象牙質および健全象牙質と判断した部位の任意の9点で音響インピーダンス値を測定した．その後，組織学的評価のために走査型電子顕微鏡（SEM）を用いて薄切片を観察した．</p><p>超音波顕微鏡画像は，音響インピーダンス値に基づいて二次元カラー画像として可視化された．これらの画像では，マクロ画像でう蝕象牙質と診断された領域に一致して青色を呈する部分が観察され，緑色を呈する健全象牙質とは明らかに異なった．各切片で計測された音響インピーダンス値の平均は健全象牙質（6.75±0.15kg/m²s）に比較してう蝕象牙質（2.47±0.44kg/m²s）では，有意に低かった（p＜0.001）．SEMの観察では超音波顕微鏡画像で黄緑色を呈した部位では均一な象牙細管構造がみられ，青色の部分では不規則で破壊された象牙細管がみられた．超音波顕微鏡画像における所見は，エックス線画像とSEM画像での所見と矛盾しなかった．</p><p>以上の結果より，超音波顕微鏡により測定された音響インピーダンス値によってう蝕象牙質が健全象牙質と判別され，う蝕を客観的に評価しうることが示唆された．</p>

Objective. To determine the optimal scan settings (scan mode and position of field of view [FOV]) for cone beam computed tomography to reduce root fracture-like artifacts that are often observed in teeth filled with gutta-percha cones (GPCs). Study Design. Fracture-like artifacts that appeared on cone beam computed tomography images of 9 extracted human mandibular premolars filled with GPCs were analyzed using I-mode (FOV, 102 mm; voxel size, 0.2 mm) and D-mode (FOV, 51 mm; voxel size, 0.1 mm) settings. Results. The artificial lines were more obvious in I-mode than in D-mode. Increased distance between the center of the FOV and the GPCs produced stronger artificial lines in both I-mode and D-mode. Conclusion. To reduce fracture-like artifacts, it is critical to use a mode with small voxel size and to place the target tooth in the center of the FOV.

To ascertain whether steroid therapy evokes dentin hypersensitivity (DH)-like tooth pain, we performed a study based on compelling evidence from patients receiving steroid therapy. An exploratory study was conducted using a questionnaire for 220 patients prescribed steroids who attended the Department of Hematology and Rheumatology of Tohoku University Hospital. Group comparisons between patients with and without steroid pulse therapy were analysed by statistical means. In this study, any DH-like tooth pain that commenced subsequent to steroid treatment was defined as steroid-derived (SD) tooth pain. The prevalence of SD tooth pain was 17.7% (39/220 patients). SD tooth pain was triggered in many vital teeth by cold and/or hot water (84.2% and 23.7%, respectively) with the pain characterised as continuous, in contrast to typical DH tooth pain. SD tooth pain was significantly more frequent in pulse therapy patients than in non-pulse therapy patients (p &lt; 0.05). Logistic regression analysis adjusted for age and sex showed similar results (odds ratio = 3.74, p = 0.013). Moreover, a positive correlation was observed between the steroid dose and pain score (rho = 0.642). Dose reduction or discontinuation of steroid therapy relieved SD tooth pain in all cases. Thus, steroid therapy can evoke DH-like tooth pain during treatment. (C) 2016 The Authors. Production and hosting by Elsevier B.V. on behalf of Japanese Pharmacological Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Background: Alveolar bone is often lost after tooth extraction. Few studies have assessed the longitudinal changes in bone volume that occur within these extraction sites. Purpose: To investigate the longitudinal morphological changes in extraction sockets following sustained continuous subcutaneous infusion of human recombinant insulin-like growth factor I (IGF-I). Materials and Methods: Fourteen rats were subjected to right mandibular first molar extraction. Experimental rats (n = 7) received a continuous subcutaneous infusion of human recombinant IGF-I (320 mg/day) for 3 weeks by osmotic minipump. Control animals were treated with saline via the same method (n = 7). All rats were then housed for an additional 3 weeks. Micro-CT scanning was performed immediately after tooth extraction and at 1, 2, 3, and 6 weeks after extraction. Results: New bone formation was markedly higher in the IGF-I-treated group as compared with the control group. The loss in alveolar ridge height in the IGF-I group was significantly lower than that in the control group at each time point after extraction on the buccal side and at 2, 3, and 6 weeks on the lingual side. Conclusions: IGF-I treatment increases the volume of newly formed bone and reduces the loss in alveolar ridge height following tooth extraction.

Objective. To clarify the cause of artificial tooth-root fracture lines in cone beam computed tomography (CBCT) images caused by root canal filling materials and to enhance the diagnostic performance of CBCT. Study Design. We analyzed the CBCT images of 18 extracted human teeth (9 upper central incisors and 9 lower premolars) that were filled with a size 50 gutta-percha cone and inserted into tooth sockets in a human skull. Results. The CBCT images of the incisors displayed artificial lines in the oblique directions, notably the mesiobuccal, distolingual, distobuccal and mesiolingual directions, but only rarely in the cross-directions (buccal, lingual, mesial, and distal). In the premolars, the reverse was true, with lines mainly in the cross-directions, mesial and distal directions particularly. The lines were predominantly at the cervical slice. Conclusions. Artifacts resulting from root filling material appear along the long axis of the alveolar bones, and resemble root fractures.

The aim of this study was to compare cone-beam computed tomography (CBCT) with intraoral radiography (parallel and bisecting techniques) for their detection capabilities of various horizontal angle root fractures in human teeth. Eighty-one extracted human upper central incisors were divided into three groups: (1) right-angle group (n = 27), in which a groove was formed perpendicular to the long axis of the root at the middle of the root; (2) 75-degree group (n = 27), which was grooved at 75A degrees in the cervical third of the root; and (3) 55-degree group (n = 27), which was grooved at 55A degrees in the middle third of the root. In an additional control group (n = 9), the teeth remained without grooves. The specimens were examined by the above-mentioned three imaging techniques by seven oral radiologists, and the grooves were visualized as radiolucent lines traversing the roots. The detection sensitivities for the parallel technique and CBCT were significantly greater than those for the bisecting technique for the right-angle and 75-degree groups, whereas the bisecting technique and CBCT showed significantly greater detection sensitivities than the parallel technique for the 55-degree group. There were no significant differences in specificity among the three imaging techniques. CBCT demonstrated high diagnostic accuracy for teeth with root fractures at any angle. When fracture lines are not located clearly by intraoral radiography at only one projection angle, additional intraoral radiography with different angles can improve detection.

The purpose of this study was to clarify the diagnostic value of capsule-like rim enhancement (CLRE) on magnetic resonance imaging (MRI) for distinguishing malignant from benign tumours of the parotid gland. We retrospectively evaluated contrast-enhanced T1-weighted images of 100 patients with malignant and benign parotid tumours for the presence, completeness, and irregularity of CLRE and its maximum thickness. We investigated any correlation of imaging and histopathological findings for 51 cases showing CLRE with available histology. The presence and completeness of CLRE did not differ significantly between benign and malignant tumours. Malignant tumours had more irregular CLRE than benign tumours (P &lt; 0.05). The mean CLRE thickness was significantly greater for malignant (2.4 mm) than benign tumours (1.4 mm) (P &lt; 0.0001). The two types of tumour were most accurately distinguished using a cut-off value of 1.5 mm thickness. Histopathology demonstrated the general correspondence of thick CLRE on MRI in malignant tumours with thick but sparse fibrous tissue and infiltration of tumour cells and lymphocytes, whereas thin CLRE in benign tumours typically represented dense fibrous tissue without infiltration of tumour cells. CLRE was more irregular and thicker in malignant tumours than in benign tumours, which may be of help in differentiating them.

Our newly developed umami taste sensitivity test revealed the loss of only the umami taste sensation in some elderly patients, whereas the other four basic taste sensations (sweet, salty, sour, bitter) were normal. Such patients all complained of appetite loss and weight loss, resulting in poor overall health. As a treatment for taste disorder patients, improvement of salivary flow has been adopted in our clinic. Umami taste stimulation increases salivary flow rate of not only major but also minor salivary glands. After treatment with umami taste stimulation, patients remarkably regained their appetite, weight and overall health. Sensitivity to umami taste seems to contribute to good overall health in elderly people.

There is a close relationship between perception of umami, which has become recognized as the fifth taste, and the human physical condition. We have developed a clinical test for umami taste sensitivity using a filter paper disc with a range of six monosodium glutamate (MSG) concentrations. We recruited 28 patients with taste disorders (45-78 years) and 184 controls with no taste disorders (102 young [18-25 years] and 82 older [65-89 years] participants). Filter paper discs (5 mm dia.) were soaked in aqueous MSG solutions (1, 5, 10, 50, 100 and 200 mM), then placed on three oral sites innervated by different taste nerves. The lowest concentration participants correctly identified was defined as the recognition threshold (RT) for MSG. This test showed good reproducibility for inter-and intra-observer variability. We concluded that: (1) The RT of healthy controls differed at measurement sites innervated by different taste nerves; that is, the RT of the anterior tongue was higher than that of either the posterior tongue or the soft palate in both young and older individuals. (2) No significant difference in RT was found between young adults and older individuals at any measurement site. (3) The RT of patients with taste disorders was higher before treatment than that of the healthy controls at any measurement site. (4) The RT after treatment in these patients improved to the same level as that of the healthy controls. (5) The cutoff values of RT, showing the highest diagnostic accuracy (true positives + true negatives), were 200 mM MSG for AT and 50 mM MSG for PT and SP. The diagnostic accuracy at these cutoff values was 0.92, 0.87 and 0.86 for AT, PT and SP, respectively. Consequently, this umami taste sensitivity test is useful for discriminating between normal and abnormal umami taste sensations.

Prednisolone is a member of synthetic glucocorticoids which are widely used to treat chronic inflammatory diseases. In this study, neuronal degeneration and cell death, and glial reaction were investigated in the rat trigeminal ganglion (TG) and brainstem after subcutaneous injection of prednisolone for 7 days. Expression of c-Jun activating transcription factor 3 and caspase-3 was absent or infrequent in the TG, and cranial sensory and motor nuclei of saline- and prednisolone-treated animals. In these animals, distribution of calcitonin gene-related peptide-immunoreactive (-IR) neurons and nerve fibers was similar in the brainstem. In addition, the number of Iba1- and glial fibrillary acidic protein (GFAP)-IR cells with some processes in the brainstem was barely affected by prednisolone treatment. However, the treatment increased ramification of Iba1-IR processes in the subnucleus caudalis of the trigeminal sensory complex. Prednisolone scarcely influenced the morphology of GFAP-IR cells in the brainstem. Expression of p38 mitogen-activated protein kinase was very rare in the brainstem of saline- and prednisolone-treated animals. The present study suggests that microglia are activated by prednisolone in the subnucleus caudalis of the trigeminal sensory complex. The glucocorticoid may affect nociceptive transmission in the brainstem.

This study was carried out to collect and analyze the data obtained from patients to establish the ideal education system for clinical training at university dental hospitals.<br>For this purpose, we obtained the information from the outpatients who visited the Tohoku University Dental Hospital using a questionnaire for our education and clinical training system.<br>The following results were obtained.<br>(1) "Referral from general practitioner" was the most common reason for visiting our hospital for new patients and patients aged younger than 40, while "reliable treatment" was the most common reason for revisiting patients and patients aged over 40.<br>(2) Most patients accepted the treatment and observation by interns and undergraduate students regardless of generation. Revisiting patients refused to see them less than new patients.<br>(3) The permissible time for clinical training purposes was longer in revisiting patients and patients aged over 50 compared with new patients and patients aged younger than 50, respectively.<br>These results suggested that elderly and revisiting patients were more cooperative with our clinical training program than younger and newer patients through the assurance of extensive safety and conscientiousness regarding treatment.

Introduction: The purpose of this article was to test the theory that short miniscrews will decrease the possibility of damaging the root, but the failure rate will increase. Methods: One hundred eighty-six miniscrews (diameter, 1.3 X 5 mm, n = 63; 6 mm, n = 62; 7 mm, n = 61) were placed in 105 consecutive patients. Multislice computed tomography and cone-beam computed tomography scans were taken before and after miniscrew placement. Insertion torque was measured at miniscrew placement. Results: The success rate of the miniscrews in the maxilla (93.4%) was higher than that in the mandible (70.3%). A significantly lower success rate with 5-mm miniscrews was observed compared with 6-mm and 7-mm miniscrews in the mandible. Miniscrews placed in less than approximately 3.8 mm of bone and those within 1.4 mm of the root had significantly higher failure rates. Miniscrews placed with insertion torque greater than 10 Ncm had a tendency for a lower success rate. Conclusions: The optimum lengths of miniscrews of a diameter of 1.3 mm are 5 mm in the maxilla and 6 mm in the mandible. They should be placed at a distance from the root with insertion torque less than 10 Ncm for safe orthodontic anchorage without failure.

Objectives: To evaluate the effects of artificially decreased occlusal vertical dimension on the fiber phenotypes of the masseter muscle in the rat. Materials and methods: The experimental animals were divided into two groups: A decreased occlusal vertical dimension (DOVD) group and a sham-operated control group. Five rats from each group were sacrificed on days 0, 3, 7, and 14 after the operation. The extent of DOVD, the masseter muscle fiber composition, and fiber diameter were analyzed. Results: The average decrease in the vertical dimension was 1.1 ± 0.5. mm. The masseter muscle fiber composition of Type IIA and Type IIB muscle fibers shifted significantly in favor of Type IIA fibers on day 3 in the DOVD group. Toward the end of the observation period, shifting occurred back to the original composition. A significant decrease in the diameter of muscle fibers was seen on day 3 in the DOVD group. Conclusion: In this experiment, when the occlusal vertical dimension was artificially reduced, the masseter muscle atrophied and the muscle fiber type changed temporarily while adapting to the new position of the mandible. © 2012 Elsevier Ltd and the Japanese Orthodontic Society.

Objective: Minor salivary gland flow rate (MF) has been proposed as a key feature of xerostomia (subjective feeling of dry mouth). To assess its diagnostic performance, MF was compared in xerostomia and control subjects. Design: Sixty-six subjects with xerostomia and 30 controls were enrolled. MF was measured in the lower labial mucosa using the iodine-starch filter paper method. Stimulated whole salivary flow rates were also measured using the gum test (stimulated-WF). Results: Both labial-MF and stimulated-WF were significantly lower in xerostomia subjects than in controls. There was a positive correlation between labial-MF and stimulated-WF in control but not xerostomia subjects. In xerostomia subjects compared to controls, there was a significantly larger reduction in labial-MF than in stimulated-WF. Xerostomia was most accurately diagnosed using a labial-MF cutoff value of 0.25 mu L/cm(2)/min. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at this cutoff value were 1.00, 0.87, 0.93, 1.00, and 0.96, respectively. Compared to respective values of 0.64, 1.00, 1.00, 0.56, and 0.75 for stimulated-WF at the traditional cutoff of 1.0 mL/min, these data indicate the higher sensitivity, negative predictive value, and diagnostic accuracy of labial-MF. Conclusions: Xerostomia was more strongly related to reduction of labial-MF than to that of stimulated-WF. Xerostomia was most likely triggered at a labial-MF cut-off value of 0.25 mu L/cm(2)/min based on results from the iodine-starch method. (C) 2012 Elsevier Ltd. All rights reserved.

Objective: Minor salivary gland flow rate (MF) has been proposed as a key feature of xerostomia (subjective feeling of dry mouth). To assess its diagnostic performance, MF was compared in xerostomia and control subjects. Design: Sixty-six subjects with xerostomia and 30 controls were enrolled. MF was measured in the lower labial mucosa using the iodine-starch filter paper method. Stimulated whole salivary flow rates were also measured using the gum test (stimulated-WF). Results: Both labial-MF and stimulated-WF were significantly lower in xerostomia subjects than in controls. There was a positive correlation between labial-MF and stimulated-WF in control but not xerostomia subjects. In xerostomia subjects compared to controls, there was a significantly larger reduction in labial-MF than in stimulated-WF. Xerostomia was most accurately diagnosed using a labial-MF cutoff value of 0.25 mu L/cm(2)/min. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at this cutoff value were 1.00, 0.87, 0.93, 1.00, and 0.96, respectively. Compared to respective values of 0.64, 1.00, 1.00, 0.56, and 0.75 for stimulated-WF at the traditional cutoff of 1.0 mL/min, these data indicate the higher sensitivity, negative predictive value, and diagnostic accuracy of labial-MF. Conclusions: Xerostomia was more strongly related to reduction of labial-MF than to that of stimulated-WF. Xerostomia was most likely triggered at a labial-MF cut-off value of 0.25 mu L/cm(2)/min based on results from the iodine-starch method. (C) 2012 Elsevier Ltd. All rights reserved.

安全で確実なインプラント治療のために、埋入前CT検査による顎骨の3次元的画像診断の重要性が増している。今回われわれは、2006年4月から2011年3月までに、東北大学病院にてインプラントの術前CT検査を施行した1,018例について臨床統計学的検討を行った。1.性別は男性346例、女性672例で女性が多かった。2.年齢は16歳から86歳で、平均年齢は男性53.9歳、女性52.8歳、年齢分布では男女とも50歳代が最も多かった。3.全CT検査に占めるインプラント術前検査の割合は23.0%であった。4.撮影の依頼元は開業歯科医院からが70.0%、院内各科からが30.0%であった。5.撮影用ステントの使用割合は70.1%であった。6.インプラント予定本数は院内からの依頼では平均3.47本、開業歯科医院からの依頼では平均4.92本であった。最頻値は両者とも2本で6本以下に8割以上の症例が含まれた。7.インプラント予定部位は、下顎臼歯部片側が最も多く、次いで下顎臼歯部両側、上顎臼歯部片側、上顎臼歯部両側の順であった。最も少なかったのは下顎前歯部片側であった。8.インプラント予定部位の顎骨形態以外に指摘した画像所見があった症例は76.7%で、上顎洞粘膜肥厚・粘液貯留襄胞の疑いが最も多く、次いで根尖病巣・歯根襄胞、重度の歯周炎による骨吸収であった。(著者抄録)

Tongue enlargement and mandibular prognathism are clinically recognized in almost all patients with acromegaly. An acromegalylike rat model recently developed by exogenous administration of insulin-like growth factor I ( IGF-I) was used to investigate morphological and histopathological changes in orofacial structures and to clarify whether these changes were reversible. Exogenous administration of IGF-I evoked specific enlargement of the tongue with identifiable histopathological changes (increased muscle bundle width, increased space between muscle bundles, and increased epithelial thickness), elongation of the mandibular alveolar bone and ascending ramus, and lateral expansion of the mandibular dental arch. Regarding histopathological changes in the mandibular condyle, the cartilaginous layer width, bone matrix ratio, and number of osteoblasts were all significantly greater in this rat model. After normalization of the circulating IGF-I level, tongue enlargement and histopathological changes in the tongue and mandibular condyle were reversible, whereas morphological skeletal changes in the mandible remained.

Objective. The accuracies of intraoral radiography (IOR), multidetector helical computerized tomography (MDHCT) at slice thicknesses 0.63 mm and 1.25 mm, and limited cone-beam computerized tomography (LCBCT) were compared for detection of horizontal tooth root fracture. Study design. In 7 beagle dogs, 28 maxillary anterior teeth were used, of which 13 had artificially induced horizontal root fracture. The specimens were examined by the above-mentioned 4 modalities. Diagnosis of root fracture was based on direct visualization of radiolucent line in each image by 6 radiologists. Results. Sensitivity, negative predictive value, and diagnostic accuracy (true positives + true negatives) for detecting fracture lines in LCBCT (0.96 +/- 0.04, 0.97 +/- 0.03, 0.93 +/- 0.04, respectively) were significantly higher than MDHCT at 0.63 mm (0.76 +/- 0.09, 0.8 +/- 0.05, 0.8 +/- 0.05, respectively), MDHCT at 1.25 mm (0.49 +/- 0.09, 0.66 +/- 0.04, 0.69 +/- 0.05, respectively), and IOR (0.51 +/- 0.18, 0.67 +/- 0.08, 0.69 +/- 0.08, respectively). Specificity and positive predictive value showed no significant intermethod difference among the 4 modalities. Conclusion. Limited cone-beam CT is more useful than the other 3 radiographic modalities for diagnostic imaging of horizontal tooth root fracture. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:e70-e74)

Objective: To investigate morphological changes in the dental arches of acromegaly-like rats recently developed by means of exogenous IGF-1 administration. Design: Human recombinant lGF-I (640 mu g/day) was continuously administered subcutaneously for 4 weeks by osmotic mini-pumps to 10-week-old male rats (n = 6). Control animals were injected with saline alone (n = 6). After administration, all the rats were housed for 4 more weeks. Arch width (W), length (L) and angle (theta) in the mandible and maxilla were measured once a week during and after IGF-I administration. Results: The concentration of circulating IGF-1, and W and theta in the mandible were significantly increased as compared with the control rats. Although the mandibular dental arch stopped expanding once administration ended, it did not return to the control size. Conclusions: in our acromegaly-like rat model, mandibular dental arch growth is greater in the lateral than antero-posterior direction during and after IGF-1 administration. (c) 2008 Elsevier Ltd. All rights reserved.

Mandibular protrusion accompanies acromegaly or acrogigantism. To clarify the detailed mechanisms, we used an acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I). Human recombinant IGF-I (640 mu g/day) continuously was infused subcutaneously to 10-week-old male rats (n = 12) for four weeks. Control, sham-operated animals (n = 12) were injected with saline alone. Twelve rats (six from each group) were killed immediately after ending administration at age 14 weeks. Another 12 rats (six from each group) were housed for an additional four weeks after treatment ended. Mandibular condylar length increased significantly in the IGF-I rats compared with the control rats, but no significant intergroup difference was found in the lengths of the coronoid and angular processes. Cartilaginous layer width, bone matrix volume, and the number of osteoblasts in the mandibular condyle increased significantly in the IGF-I group. These histopathological changes in the condyle disappeared after IGF-I administration was discontinued; however, the morphological change in condylar length remained. These findings suggest that mandibular protrusion in patients with acromegaly or acrogigantism may be evoked by superfluous elongation of the mandibular condyle and that such elongation can be induced by endochondral ossification caused by high IGF-I serum levels.

This study was designed to determine if sympathetic nerve fibers exist in dentinal tubules in rat normal dental pulp, and if they sprout into the dentinal tubules in response to artificial cavity preparation in dentin. Sympathetic nerve fibers in rat molar dental pulp were labeled using an anterograde axonal transport technique involving injection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the superior cervical ganglion (SCG). They were then observed using light and electron microscopes. In normal dental pulp (control), scattered WGA-HRP reaction products were observed in unmyelinated nerve endings in the odontoblast layer and subodontoblastic region. In injured pulp 3 weeks after cavity preparation, reaction products were about 1.8-times more plentiful in the above areas (versus control pulp). However, no labeled nerve fibers were observed in the dentinal tubules in either control or injured dental pulp. These results indicate that although sympathetic nerve fibers do indeed sprout in rat dental pulp in response to cavity preparation, they do not penetrate into the dentinal tubules in which postganglionic nerve endings derived from the SCG were not originally present. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

This study was designed to determine if sympathetic nerve fibers exist in dentinal tubules in rat normal dental pulp, and if they sprout into the dentinal tubules in response to artificial cavity preparation in dentin. Sympathetic nerve fibers in rat molar dental pulp were labeled using an anterograde axonal transport technique involving injection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the superior cervical ganglion (SCG). They were then observed using light and electron microscopes. In normal dental pulp (control), scattered WGA-HRP reaction products were observed in unmyelinated nerve endings in the odontoblast layer and subodontoblastic region. In injured pulp 3 weeks after cavity preparation, reaction products were about 1.8-times more plentiful in the above areas (versus control pulp). However, no labeled nerve fibers were observed in the dentinal tubules in either control or injured dental pulp. These results indicate that although sympathetic nerve fibers do indeed sprout in rat dental pulp in response to cavity preparation, they do not penetrate into the dentinal tubules in which postganglionic nerve endings derived from the SCG were not originally present. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

We report here a case of masticatory disturbance evoked by trigeminal schwannoma, in which we have evaluated the changes in occlusal force and masticatory sensation before and after treatment for the tumour. The patient was a 43-year-old woman and her chief complaint was a loss of masticatory sensation on her left side. MR imaging revealed an enhanced tumour in the left cavernous sinus/Meckel's cave. The left masseter muscle function and occlusal force showed remarkable decreases before treatment; however, the sensory thresholds of her facial skin and dental pulp were not significantly different from the control side, indicating that her loss of masticatory sensation was not due to sensory disturbance but to occlusal force weakness. Gamma-knife radiosurgery resulted in a significant improvement in masticatory sensation following an increase in occlusal force.

Introduction: We have successfully treated skeletal open bite by intruding posterior teeth with the skeletal anchorage system. Our aim in this study was to morphologically and hemodynamically evaluate the changes in pulp tissues when molars are radically intruded. Methods: The mandibular fourth premolars of 9 adult beagle dogs were divided into 3 groups: a sham operated group (n = 6, 3 dogs), 4-month intrusion group (n = 6, 3 dogs), and a further 4-month retention group (n = 6, 3 dogs). We evaluated the morphological changes of the pulp and dentin-the amount of vacuolar degeneration in the odontoblast layer, the predentin width and nervous continuity in the pulp tissue, and the pulpal blood-flow response evoked by electrical stimulation in the dental pulp. Results: Extreme molar intrusion with the skeletal anchorage system caused slight degenerative changes in the pulp tissue, followed by recovery after the orthodontic force was released. Circulatory system and nervous functions were basically maintained during the intrusion, although a certain level of downregulation was observed. These morphologic and functional regressive changes in the pulp tissue after molar intrusion improved during the retention period. Conclusions: Histologic changes and changes in pulpal blood flow and function are reversible, even during radical intrusion of molars.

東北大学歯学部附属病院における患者の診療および教育に対する意識を明らかにすることを目的に,2006年に本院を受診した新来患者1,108人にアンケート調査を行い,回収できた1,020人の結果をまとめ,以下の結論を得た。(1)来院の理由は,「他の病院から紹介されたから」が最も多く,次いで,「安心した治療を受けたいから」,「最新の治療を受けたいから」などであった。(2)治療の際に不満に思うことは,「特にない」が最も多く,次いで,「待ち時間」,「研修医や学生の見学」などであった。(3)学生および研修医の教育への協力は,「学生・研修医の教育に協力できる」が最も多く40.6%で,逆に,「どちらも協力したくない」は8.4%であった。(4)適当と思われる治療時間は,30分が最も多く,次いで,「時間は気にしていない」,1時間などであった。(5)回答結果(内容)の一部に男女差が認められた。To assess patient attitude regarding our clinical and educational systems, we analyzed questionnaire data obtained from 1, 020 patients who visited the Tohoku University Dental Hospital in 2006. The following results were obtained. 1) The most frequent reason for visiting our hospital was referral from another clinic, the second was for safe treatment, and the third was the desire to undergo progressive treatment. 2) More than half of the patients (56.6%) were satisfied with the treatment in our hospital. The remaining patients were dissatisfied with the long waiting time (15.2%), observation by the students or residents (4.4%), etc. 3) Nearly 40% of the patients agreed to undergo treatment by either students or residents, while 8.4% did not. 4) The majority of patients (41.5%) considered 30 minutes as an adequate chair time. 5) There were significant differences between male and female responses in some results.

顎顔面の解剖学的形態や機能、骨代謝や骨のリモデリングがヒトに類似しているカニクイザルを実験材料として用い、卵巣摘出後の下顎頭の形態学的変化についてX線学的および組織学的に検索した。OVX群は両側卵巣摘出術、Sham群は開腹手術のみを施行した。側斜位経頭蓋撮影法による下顎頭の骨塩量は、両群で有意差は認めなかった。μCTによる下顎頭骨形態計測解析では、OVX群がSham群に比べ、海綿骨の骨密度が低下し、骨梁が疎になっていたが、皮質骨では骨密度の低下はみられなかった。組織学的にOVX群の下顎頭の軟骨肥大層は菲薄化し、肥大化軟骨細胞数は減少した。エストロゲンの減少のみでは変形性顎関節症は起こりにくいことが示唆された。

An acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I) was used to investigate morphological and histopathological tongue changes and clarify whether the changes were reversible. Human recombinant IGF-I (640 mu g/day) was-continuously subcutaneously infused into ten-week-old male rats for four weeks (IGF-I group; n=6). Control sham-operated animals were injected saline alone (control group; n=6). Rats were sacrificed immediately on ending administration at the age of fourteen weeks. Another 12 rats (6 from each group) were housed for an additional four weeks after administration ended. Total IGF-I (human + rat) increased significantly during administration, returning to control levels afterwards. Tongue weights significantly increased with histopathological changes present (increases in the muscle-bundle width, spaces between muscle-bundles and epithelium thickness) in the IGF-I group compared to control rats. Tongue size returned to control levels after discontinuation of IGF-I administration. These findings suggest that the characteristic tongue enlargement was developed experimentally in our acromegaly-like rat model, and that such morphological and histopathological tongue changes are reversible on normalization of circulating IGF-I levels.

歯痛を主訴とする外来患者123名に対して問診,臨床診査およびX線検査を順に行い,ステップ毎の診断名と確定診断名との一致率を調査し,以下の結論を得た.問診のみから確定診断が得られたのは82.1%,問診と臨床診査から確定診断が得られたのは15.4%,問診+臨床診査+X線写真で確定診断が得られたのは2.4%であり,確定診断が得られなかった症例はなかった.確定診断の内訳は,歯髄炎,周縁性歯周囲炎,根尖性歯周炎,智歯周囲炎および象牙質知覚過敏症であり,問診のみで得られた正診率は,どの疾患においても8割程度あるいはそれ以上であった.疾患別の問診による正診率に有意差はなかった

<b>Purpose:</b> To investigate morphological changes in the mandible using the recently developed acromegaly-like rat model, induced by exogenous administration of insulin-like growth factor I (IGF-I), and to clarify whether the changes are reversible after normalization of the circulating IGF-I level.<br><b>Material and methods:</b> Human recombinant IGF-I (SOMAZON, Astellas Pharma Inc., Tokyo, Japan) (640μg/day) was subcutaneous infused continuously to 10-week-old male rats for 4 weeks (IGF-I group) (n=6). The control sham-operated animals were injected with saline alone (control group) (n=6). Rats were sacrificed immediately on ending administration (age 14 weeks). Another 12 rats (6 from each group) were housed for an additional 4 weeks after administration ended. Measurement of body weight and blood sampling were done before sacrificing rats (at age 14 and 18 weeks). Then, IGF-I serum level was measured from the sera. After sacrificing the rats, their mandibles were excised. Morphological analysis on the mandible was performed on lateral cephalometric image using soft X-ray equipment (SOFTEX Type CMB, SOFTEX Corp., Tokyo, Japan).<br><b>Results:</b> Body weights, as well as total IGF-I (human+rat) serum level was markedly higher in the IGF-I group during administration of IGF-I, with a return to the control level after IGF-I administration ceased. Some linear mesurements of the mandible, i. e., Mental foramen (MeF) -Condyle (Cd), MeF-Infradentale (Id), Mandibular foramen (MaF)-Cd, MaF-Id, Cd-Id and Cd-Deepest point of the antegonial notch, significantly increased in the IGF-I group as compared with the control group both during and after IGF-I administration (age 14 and 18 weeks).<br><b>Conclusion:</b> In our acromegaly-like rat model, specific enlargement of the mandible was found in the length of the condylar process and mandibular body. Such morphological changes were not reversible after normalization of the circulating IGF-I level.

口腔乾燥症患者における口腔粘膜保湿度と総唾液分泌量との関連について検討した。対象は, 口腔乾燥症患者27名 (男性3名女性24名, 34歳～87歳, 平均年齢58.4歳) および健常ボランティア25名 (男性14名, 女性11名, 18歳～87歳, 平均年齢48.8歳) とした。口腔粘膜保湿度は, 口腔水分計モイスチャーチェッカー・ムーカス (MY01, スカラ社製) を用いた。総唾液分泌量は, ガムテストおよびサクソンテストによって測定した。口腔粘膜保湿度の測定部位は, 頬粘膜, 舌, 口唇, 口蓋粘膜の4部位とした。その結果, 患者の口腔粘膜保湿度はボランティアと比較して統計学的有意に低下していた。一方, 総唾液分泌量の低下は, ガムテストで患者の33.3%のみに, サクソンテストで患者の63%にみられた。口腔粘膜保湿度とガムテストおよびサクソンテストによる総唾液分泌量との間に, 相関関係は得られなかった。患者の舌における口腔粘膜保湿度低下は, ほかの部位よりも統計学的有意に顕著であった。

The purpose of this study was to investigate the effect of an increase in laser power on the transmitted laser signals from vital and non-vital teeth, in the hope of achieving a better assessment of human pulp vitality with the transmitted laser-light flowmeter. The experiments were carried out on total of 61 vital teeth with no restoration (19 upper central incisors, 16 upper lateral incisors, 16 upper canines, and 10 first premolars) and five non-vital upper central incisors (the root canals of which were filled with gutta-percha) in 15 subjects aged 22-28 years. For use with transmitted laser light, the fibers within the probe of a conventional laser Doppler flowmeter (LDF) apparatus were used, one for transmitting light onto the labial surface, the other for receiving it at the palatal surface of the same tooth, as reported previously. Laser output power was set at the original 2 mW and also at 5, 7, and 10 mW. The number of vital teeth displaying a blood flow (BF) signal at each laser power setting was: 1) 12/19 central incisors at 2 mW, 19/19 at 5, 7, and 10 mW, 2) 19/19 lateral incisors at 2, 5, 7, and 10 mW, 3) 0/16 canines at 2 mW, but eight, 12, and 14 at 5, 7, and 10 mW, 4) 0/10 first premolars at 2, 5, 7, and 10 mW. Thus, an increase in laser power increased BF detection from the thicker teeth (but not from premolars). In addition, clearer BF signals synchronized with heart rate, and greater passive BF changes secondary to blood pressure (BP) changes were observed at higher laser settings. In non-vital teeth, no signals synchronized with heart rate or BP changes were observed, indicating that no BF signal of non-pulpal origin was ever monitored with this ballistic light even when the laser power was increased. These results indicate that high-powered transmitted laser light could be a useful tool both for monitoring pulpal BF and for the assessment of tooth-pulp vitality.

Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplasia. In order to define the morphologic characteristics of the masseter Muscle incidental to bone abnormalities, we present 3 cases of CCD with the masseter muscle thickness and maxillofacial bone abnormalities, using computed tomography (CT) and panoramic radiographs. In CCD patients (a) the masseter muscles were less thick than in age- and sex-matched control subjects, (b) the zygomatic arch was discontinuous with the hypoplastic zygomatic bone, (c) the ascending ramus of the mandible had parallel-sided borders, and (d) the coronoid process pointed upwards and/or posteriorly. We have concluded the masseter muscles are less thick than normal, alongside the maxillofacial bone abnormalities in CCD patients.

To help us investigate the time course of mandibular enlargement in acromegaly or acrogiantism to determine the most suitable period for occlusal treatment in this disease, our aim was to develop a rat model of acromegaly (acrogiantism). In this study, prominent mandibular enlargement was induced by continuous subcutaneous infusion of human recombinant insulin-like growth factor-I (IGF-I) (640 mug/day) in 10-week-old male rats for 4 weeks (n = 6); the control sham-operated group was injected with saline alone (n = 6). Circulating human IGF-I was clearly detectable in the IGF-I group during the four-week administration period, while endogenous rat IGF-I levels decreased. Total IGF-I (human + rat) increased significantly during administration, returning to control levels afterwards. The length of every bone examined (mandible, maxilla, and femur) showed a significant increase compared to control rats, especially the mandible. Although the mandible did not continue to grow after discontinuation of IGF-I administration, it did not return to control size, unlike the maxilla and femur, and disharmonious jaw size (between maxilla and mandible) persisted even after circulating IGF-I levels normalized. These findings in our rat model suggest that mandibular occlusal treatment should only be considered for acromegalic (acrogiantic) patients after serum IGF-I levels have normalized and bone growth has ceased.

The lack of published information about the minor salivary glands is due in part to the difficulties experienced in collecting and quantifying their secretions. In fact, no method exists for measuring their secretions that is both simple and accurate. This investigation examined the accuracy of our newly developed method (which simply employs the iodine-starch reaction) in 10 healthy non-medicated adults. A strip painted with a solution of iodine in absolute alcohol then with a fine starch powder mixed with castor oil was placed at a designated location on the tower-tip mucosa for 2 min to collect sativa. Black-stained spots of various sizes corresponding to the individual glands could be accurately visualized. After removal of the strip, the total stained area (mm(2)) was calculated by digitizing the spot areas using a computer system. The correlation coefficient (r) between known volumes of saliva and stain size was 0.995, indicating a close correlation. The correlation coefficient (r) between area values obtained in the first trial in each subject (Y) and the second (X; 10 min later) was 0.963, and the simple regression equation was close to Y = X, indicating good reproducibility. The mean flow rate (mul/cm(2) per min) obtained by converting mean total area to volume and thence to flow rate was 0.49 +/- 0.26, in good agreement with published values obtained by others. These results suggest that our newly developed method allows both the distribution and secretion rate of the minor salivary glands to be observed, and that it should be of practical value due to its simplicity, accuracy, and reproducibility. (C) 2003 Elsevier Ltd. All rights reserved.

Objectives: To evaluate the usefulness of heavily T-2 weighted (T2W) magnetic resonance (MR) images for the differential diagnosis of parotid tumours. Methods: Conventional T2W and heavily T2W images obtained from 43 patients with parotid tumours were reviewed retrospectively. Tumours were classified pathologically into three types: pleomorphic adenoma (25 cases), Warthin's tumour (7 cases) and malignant tumour (11 cases). During interpretation of each MR image, special attention was paid to the homogeneity and signal intensity displayed by the solid portions of the tumours. Results: Heavily T2W images could distinguish pleomorphic adenoma from Warthin's tumour and malignant tumours based on the homogeneity and signal intensity of the solid portions, whereas conventional T2W images could not. On conventional T2W images, neither homogeneity nor signal intensity differed significantly among these three tumour types. On heavily T2W images, malignant and Warthin's tumours appeared more homogeneous than pleomorphic adenoma (P &lt; 0.0061); signal intensity from pleomorphic adenoma was significantly different to signal intensity from malignant tumours (P &lt; 0.05) and Warthin's tumour (P &lt; 0.005). Conclusions: Heavily T2W MR images can be useful in distinguishing pleomorphic adenoma from Warthin's tumour and malignant tumours.

To determine the risk of developing symptoms due to the presence of maxillary and mandibular third molars, we analyzed a reliable population sample by age, and according to third-molar position and impaction level using long-term follow-up data under conditions of good oral hygiene. Of 308 graduates from our dental school, a total of 776 third molars were followed up for periods of 11 to 27 years by means of intraoral radiographs. The development of symptoms, the participant's age, and third-molar angular position and degree of impaction were investigated. For both maxillary and mandibular third molars, the risk of developing a symptom correlated neither with angular position nor with impaction level. The first symptom associated with a third molar developed most frequently in their 20's for both maxilla (16.2%) and mandible (17.5%), with the next highest frequency being in their 30's (12.6%, maxilla; 13.0%, mandible). The status of third molars shows no relation to the subsequent development of symptoms if good oral hygiene is maintained. The low rates of symptom-development do not support removal of asymptomatic third molars. (C) 2003 Tohoku University Medical Press.

<b>Purpose</b>: To reduce intraoral radiographic errors in undergraduate clinical discipline.<br><b>Materials and methods</b>: We evaluated a total of 2, 434 intraoral radiographs taken by 50 students, during undergraduate clinical discipline in 1998, with the bisecting technique at each practice stage.<br><b>Results</b>:<br>1. The frequency of errors significantly decreased as the practice stage progressed.<br>2. Errors were most frequent in the area of the canines and premolars, followed by the molars, and least frequent in the incisors.<br>3. The most frequent cause of error was incorrect film placement, followed by vertical overangulation and cone cutting.<br><b>Conclusions</b>:<br>1. Repeated patient practice with student participation in diagnosis and treatment was considered effective for the clinical discipline of intraoral radiography.<br>2. In the teaching of intraoral radiographic practice, it is important to provide the student with a sufficient understanding of the morphology of oral structures.<br>3. It is necessary to instruct the students sufficiently in correct patient placement, film placement and cone placement.

As a new nonsurgical treatment for odontogenic maxillary sinusitis (OMS), irrigation of the maxillary sinus through the root canal of the causal tooth was carried out to the patient with OMS that had proved refractory to conservative treatments (i.e., root-canal treatment of the causal tooth and antibiotic therapy). Clinical signs, symptoms, and radiographs before and after the new treatment revealed evidence of good healing. The clinical signs and symptoms, such as oppressive pain in the cheek and retrorhinorrhoea, entirely disappeared immediately after the irrigation (which was done only once) without pain, and the obstructed ostiomeatal unit was aerated on the follow-up CT images. There was no side effect associated with saline irrigation, nor any recurrence of symptoms since the irrigation. We therefore propose the irrigation through the root canal of the causal tooth as a new treatment for periapical disease-induced maxillary sinusitis, a technique that should ensure proper ventilation and drainage by relieving obstruction of the ostiomeatal unit. - odontgenic maxillary sinusitis; nonsurgical treatment; ostiomeatal unit; apical periodontitis (C) 2002 Tohoku University Medical Press.

It has been shown earlier that electrical stimulation of the distal cut end of the inferior alveolar nerve (IAN) in the cat evokes three different patterns of pulpal blood-flow (PBF) response in the ipsilateral mandibular canine tooth (a decrease, a biphasic response, or an increase). The response to a givers stimulus sometimes changed to another pattern even in one and the same experimental animal during the course of the experiment. It is known that the evoked decrease is due to activation of the sympathetics and that the increase is due to antidromic activation of sensory fibres; but, it is unknown why the response varies so much. It is hypothesised that the baseline blood-flow (131317) modulates vasomotor responses in the dental pulp. To test this hypothesis, the effects of BBF on PBF responses elicited by the IAN stimulation mentioned above were investigated. Dynamic changes in PBF in cat mandibular canine teeth were elicited by electrical stimulation of the distal cut end of the IAN, at various BBF, with blood-flow monitored by laser Doppler flowmetry. The amplitude of the PBF vasodilator response increased as BBF was adjusted downwards (by cooling the tooth). In contrast, the amplitude of the PBF vasoconstrictor response increased as the BBF rose. Vasodilator responses could be transformed into vasoconstrictor responses, and vice versa, by alterations in the BBF. No systemic blood-pressure changes were elicited throughout the experiment. These results indicate that a consideration of baseline vascular tone is important, whenever the size of PBF responses to various stimuli is discussed or calculated. (C) 2002 Elsevier Science Ltd. All tights reserved.

Objectives: To determine the most appropriate sequences for the visualization of small parotid ducts in MR sialography. Methods: MR images of a phantom consisting of distilled water in polyethylene tubes were obtained with turbo-spin echo (TSE), single-shot turbo-spin echo (SSTSE), half-fourier acquisition, single-shot turbo-spin echo (HASTE) and turbo gradient-spin echo (TGSE) pulse sequences and compared visually and quantitatively. MR sialograms obtained from healthy volunteers and patients with Sjogren's syndrome (SS) were obtained using the same four sequences. Results: In the phantom, TSE images were best and the contrast-noise ratio (CNR) highest. In the volunteers, the main ducts were especially clearly visualized with TSE and in SSTSE; however, the majority of secondary and/or tertiary parotid ducts were not depicted by any of the sequences used. In SS patients, images of small main ducts and small pseudocysts were clearer using TSE. However, TSE could not depict the narrow main ducts or peripheral ducts or very small pseudocysts. Conclusions: TSE is considered the most suitable MR sequence for assessing small parotid gland ducts. However, further improvement is needed since it does not always visualize them sufficiently.

下顎の歯原性炎症が原因で蜂窩織炎を惹起した10症例のCT横断像の検討した.全症例で炎症は舌下間隙,顎下間隙,咀嚼筋間隙に波及していた.10例中9例で炎症は旁咽頭間隙に進展し,うち3例では炎症は頸動脈間隙に波及していた.10例中7例は炎症が重力に従い下方に進展し,患側に留まっていたが,残り3例は間隙を介して上方の側頭部や対側にまで炎症が波及していた.患側と対側で,筋と脂肪組織のCT値を比較したところ,患側と対側には有意差が認められ,患側では筋のCT地の低下,脂肪組織のCT値の上昇が認められた

The purpose of this study was to assess the condition and viability of the autogenous particulate marrow and cancellous bone grafted for alveolar cleft. In this investigation, 2 unsuccessful cases (7-year-old male and 10-year-old female) that showed marked bone resorption on CT images obtained 1 month after the operation were evaluated. The viability of bone grafts was documented by means of bone scintigraphy and MRI.<br>On the scintigrams and MRI of the 2 cases obtained 3 months after the operation, there was no evidence of acute inflammation in the operated alveolus. The scintigrams of the 2 cases revealed the decreased uptake at the cleft region and the increased uptake at the adjacent alveolus of the cleft. The decreased uptake of the cleft area gradually became wider and clearer until 14 months after the operation. On the other hand, the increased uptake at the adjacent alveolus of the cleft still partially remained at 14 months after the operation.<br>On T1-weighted MRI obtained 3 months after the operation of the second case, the grafted bone showed partially hyper intensity similar to the fatty tissues. This area extended to the adjacent alveolus on the MRI obtained 14 months after the operation.<br>From these findings we suggest that scintigraphy may be useful to evaluate postoperative avascular necrosis in the alveolar cleft, and that MRI may be useful in assessing the fatty marrow maturation of the bone bridge.

高齢化や高次医療機関としての本院へのニーズの高まりなど急速な社会1青勢の変化が, 本学歯学部臨床実習システムに与える影響と問題点を明らかにするために, 昭和61年度および平成9年度の臨床実習協力患者について詳細を調査した。その結果, 1)平成9年度は, 昭和61年度に比較して患者が高齢化していた。2)平成9年度の臨床実習協力患者において, 全身疾患有病率は25.1%であった。その中には歯科治療上注意を要する循環器疾患, 血液疾患, 糖尿病, 甲状腺疾患などの全身疾患が含まれていた。3)平成9年度の臨床実習協力患者において, 71.2%の患者に来院および診療時間の制約がみられた。その原因としては, ライフスタイルの変化に伴う多忙化や, 特に高齢者における全身疾患治療のための他科医院への通院などがあった。以上の結果は, 社会情勢の急激な変貌が臨床実習システムへ多大な影響を及ぼしている現状を反映していた。従って, 今後, 臨床実習システムにおいて, 高齢者および全身疾患有病者に対する, また社会情勢の変貌にともなう社会的ニーズに対するさまざまな配慮,が必要であると思われた。Recently, the social conditions around our hospital have changed rapidly owing to factors such as the increase in the elderly population and the need for our hospital to become a leading medical institution. To determine how these social changes affect our clinical discipline systems, we investigated the details of dental students' patients.The following results were obtained : 1)The proportion of elderly patients in 1997 was higher than that in 1986.2)In 1997,the proportion of patients who had systemic diseases was 25.1%.These diseases included cardiovascular disease, hematologic disease, diabetes and thyroid disease, conditions that require attention during dental treatment.3)In 1997,71.2% of dental students' patients could receive dental treatment only at certain times or on certain days because they were busy with work, reflecting changes in life style. In particular, elderly patients required time to consult medical doctors to receive treatment for systemic diseases.Our results indicate that rapid changes in social conditions might substantially affect our clinical discipline system.Therefore, dental students' patients who are elderly or have systemic diseases should be carefully considered in view of changing social needs.

下垂体腺腫は, 下垂体から発生する発育のゆっくりとした良性腫瘍である。今回我々は, 口腔内所見と問診から成長ホルモン(GH)産生下垂体腺腫を発見した2症例を経験したので報告する。症例1は, 52歳, 男性であり, 両側顎下部の腫脹と早口で話にくいことを主訴に来院した。5年前より身長が徐々に伸びていることを訴えていた。口腔内所見では, 下顎前歯の歯間離開, 側面頭部X線写真では, トルコ鞍の著明な拡大とdouble floorが認められ, Glabellaと後頭隆起の突出もみられた。症例2は45歳, 女性であり, 歯の充填物脱離を主訴に来院。足が少しずつ大きくなっていることを訴えていた。口腔内所見では, 下顎前歯の歯間離開および右側前歯から臼歯にいたる開咬が認められ, 側面頭部X線写真では, トルコ鞍の拡大や後頭隆起の突出がみられた。2症例ともに, 内分泌学的検査でGH値は上昇しており, MR1検査では症例1はトルコ鞍内から下方へ進展した腫瘤が, 症例2は鞍上部へ突出した腫瘤が認められた。2症例とも成長ホルモン産生下垂体腺腫による末端肥大症と診断され, 経蝶形骨洞到達法により腫瘍摘出術が施行された。術後, 成長ホルモンの値は低下し, 現在, 全身状態を考慮しながら口腔の経過観察を行っている。口腔症状を単に局所的病変としてとらえることなく, 全人的見地から口腔を診断することが重要であると思われた。Pituitary adenoma is a benign slow-growing neoplasm arising within the pituitary gland.We reported on two patients found to have growth-hormone-secreting adenomas on the basis of oral symptoms and medical interviews.The first patient was a 52-year-old man who presented with submandibular swelling and difficulty in speaking guickly.The patient has grown taller during the past 5 years.Examination of the oral cavity revealed separation of the mandibular anterior teeth.A lateral cephalogram showed enlargement and a double-floor appearance of the sella with protrusion of the occipital prominence and glabella.The second patient was a 45-year-old woman who presented with loss of a tooth filling.The size of her feet had gradually increased.Oral examination showed separation of the mandibular anterior teeth and open bite on the right side.A lateral cephalogram showed ballooning of the sella with protrusion of the occipital prominence.The growth hormone levels in both patients were high on endocrinological tests.Magnetic resonace imaging disclosed a sellar mass extending downward in patient I and a sellar mass extending upward to the suprasellar region in patients. Patients were given a diagnosis of acromegaly due to a growth-hormone-secreting adenoma.After transsphenoidal surgery, growth hormone levels declined markedly in both patients.We are now observing the patients' oral cavity in consideration of their general condition.In conclusion, it is important to comprehensively examine and diagnose oral diseases on the basis of both oral symptoms and general condition.

高齢化社会にともない, 歯科疾患以外の全身疾患を有する患者(全身疾患有病者)が歯科医院を受診する機会が増えている。この現状を把握することを目的として, 我々は昭和56年および平成8年における本院および某一般歯科医院の新来患者を対象に, 既往歴をもとに全身疾患有病者について調査した。その結果, 1)本院来院患者の全身疾患有病率は, 一般歯科医院患者の約2倍と高く, また本院では, その割合が増加していた。2)本院, 一般歯科医院ともに, 患者の年齢別有病率は, 高齢になるにつれて増加していた。特に本院では, 30歳以上の患者の65%以上, 60歳以上の80%以上が全身疾患を有していた。3)疾患別では, 本院ではアレルギー性疾患が最も多いのに対し, 一般歯科医院では循環器系疾患が最も多くみられた。また, 本院ではアレルギー性疾患を有する患者の割合が, 著明に増加していた。4)本院, 一般歯科医院ともに, 複数の全身疾患を有する患者の割合が増加していた。Owing to the increase in the elderly population, patients with various systemic diseases are visiting dental facilities more often than previously.To obtain data on dental patients with systemic diseases, we investigated trends in patients newly presenting at our hospital and at a private dental clinic in 1981 and 1996 on the basis of general history written in the patients files.The results were as follows : 1)The proportion of patients with systemic diseases at our hospital was twice that at a private dental ofiice, both in 1981 and 1996,the proportion at our hospital was higher in 1996 than in 1981.2)At both dental facilities, the proportion of patients with systemic diseases increased parallel to the patients' age. At our hospital, systemic diseases were presentin more than 65% of patients older than 30 years and in more than 80% of those older than 60 years.3) The most frequent diseases were allergic diseases at our hospital and cardiovasculer diseases at a private dental clinic.The proportion of patients with allergic diseases at our hospital increased markedly.4) At both dental facilities, the proportion of patients with more than 2 systemic diseases increased.

東北大学歯学部における臨床実習は, 建学以来, 「口腔単位」の基本理念に基づいて行われている。しかしながら, 近年のライフスタイルの変化, 開業歯科医院数の増加および高齢化などの背景から, 最近さまざまな問題点が指摘されている。そこで今回, 臨床実習の現状と問題点を明らかにすることを目的として, 学生の担当患者数とその経過について, 昭和45年度から平成9年度までの28年間の推移を調査し比較検討を行った。その結果, 1)学生1人あたりの担当患者数(5.1±1.1)に著しい変化はなく, 臨床実習システムは, 担当数においてはコンスタントに継続実施されていると思われた。しかしながら, 患者経過において, 昭和47年度から52年度までの5年間と比較して平成5年度から9年度までの5年間では, 次年度への継続の割合が増加し, 終了の割合が減少する傾向がみられ, 患者の協力(学生による治療に対する理解)に大きく依存していることが示された。2)歯学部附属病院全体の新来患者において, 紹介状を持参する患者の割合が急増し, 臨床実習協力患者として選定対象となる紹介状を持参しない患者が減少していた。このような近年の高次医療機関としての本院の特徴は, 臨床実習協力患者の確保を困難にしていると思われた。本学部の特徴ある臨床実習を継続していくために, 一般患者も来院しやすい環境づくりが, 本学部附属病院に求められる。3)平成9年度の臨床実習協力患者の確保において, 学生が自分の知り合いをつれてくる割合は40%に及んだ。4)昭和58年度と平成9年度とのdrop(治療中止)理由, および昭和55年度と平成9年度の医員引き上げ理由の内容に変化がみられた。以上, 患者, 指導教官および学生の協力で本学部の臨床実習システムが維持されている現状と臨床実習における問題点の一部が明らかとなった。Our clinical discipline system, a part of undergraduate education, has been in effect for 28 years in accordance with the educational philosophy that the dental patient must be treated as a human unit, I.e., not as clinical cases but as an oral unit.However, recent changes in social conditions surrounding university dental hospitals have made it difiicult to continue our educational system.Therefore, this retrospective survey was designed to clarify the present status and problems of the clinical discipline system at Tohoku University School of Dentistry.The following results were obtained.1) During the past 28 years, the average number of patients per year treated by one student was 5.1.2)At the end of each year, the clinical progress of each patient was classified into 4 categories, I.e., completion, continuation to next year, discontinuation, or transference to a specialist at our hospital.Recently, the rate of completion has tended to decrease, and that of continuation has tended to increase.3)The number of the patients referred from other hospitals or clinics to our hospital has greatly increased, whereas that of free patients has decreased recently.This tendency might make it difficult for patients to enter the clinical discipline system.4)Forty percent of the patients treated by students were referred to the clinical discipline system by students themselves.5)The reason for discontinuation and transference of patients differed according to the year.These results indicate that our characteristic clinical discipline system depends on the efforts of patients, instructors, and students.

本学歯学部附属病院における疾病構造の変化の一端を知ること, また, これからの本学歯学部附属病院のあり方に関する基礎的資料を得ることを目的に, 昭和55年から5年毎に昭和60年, 平成2年, 平成7年に当院を受診した新来患者について調査した結果, (1)患者数は, 年々増加傾向にあり, 特に女性患者が増加した。(2)紹介患者が著明に増加し, 平成7年では全新来患者の54.9%と, 半数以上を占めるようになった。(3)新来患者の平均年齢が上昇し, 年齢別では, 9歳以下の低年齢患者が減少し, 60歳以上の高齢患者が増加した。(4)各診療科の中では, 口腔外科への新来患者および紹介患者が最も多くみられた。(5)疾患は, 齲蝕・歯周疾患, 不正咬合, 顎関節症, 埋伏智歯・智歯周囲炎の順に多く, 齲蝕・歯周疾患および不正咬合は減少傾向にあり, 顎関節症および埋伏智歯・智歯周囲炎は増加傾向にあった。We retrospectively surveyed 19,654 new patients who visited Tohoku University Dental Hospital in 1980,1985,1990,and 1995 to study statistical tends in dental patients. The results were as follows : 1) The number of new patients tended to increase gradually, especially in females. 2) The number of referral patients markedly increased over the years, and in 1995 referral patients accounted for 54.9% of all new patients. 3) The average age of new patients increased, and the number of new patients who were less than 9 years old decreased, while the number of new patients who were more than 60 years old increased during the study period. 4) As for the clinical department consulted, most new patients, including referral patients, visited the oral surgery department. 5) The most common diagnoses were dental caries and periodontal disease, malocclusion, temporomandibular joint disorders, and impacted third molars and pericoronitis, in descending order. Furthermore, the number of patients with dental caries and periodontal disease and malocclusion tended to decrease, while that of patients with temporomandibular joint disorders and impacted third molars and pericoronitis tended to increase during the study period.