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Acquiring adequate attached mucosa is important in restoring masticatory function with a removable dental prosthesis or dental implant. In patients with inadequate attached mucosa, a free gingival graft (FGG) with a custom stent is used. However, it is challenging to apply the conventional method for fabricating a stent with a reshaped cast in patients with reconstructed mandibles because the reconstructed mandible has limitations due to a titanium mesh, skin flap, and unique bone morphology. In the present report, we have proposed a new design and fabrication process for a mucocompressive splint via medical engineering to acquire the attached mucosa for the prosthodontic treatment of reconstructed mandibles.Three-dimensional (3D) craniomandibular models were reconstructed from a computed tomography dataset after mandibular reconstruction. The dentition region was replaced with highly precise scan data of the dental casts using a 3D scanner. The alveolar ridge mucosa and teeth were ideally designed using the 3D model while referring to the anatomical structures. The jig used to fabricate the working dental cast with artificial gum in real space was designed and fabricated using a 3D printer. The alveolar ridge was altered into a simulated configuration on the articulator using a jig. A mucocompressive splint was fabricated on an altered dental cast. The splint was immediately seated on the mandible without any major adjustments after the FGG.Adequate attached mucosa for the prosthodontic treatment of a reconstructed mandible was obtained by the pre-surgical fabrication of a mucocompressive splint through medical engineering.

Introduction Displacement of provisional fixed prostheses may result in undesirable and embarrassing outcomes in dental treatments, especially in endodontic treatment. Development of certain counter measures has been necessary to avoid such discomforts. Aim The aim of this report was to propose a pre-endodontic post and core technique to achieve smooth progress of the treatment. Materials and methods The patient was a 59-year-old male diagnosed with an infraocclusion caused by wear of his teeth. He received full mouth provisional fixed restorations for a complete oral rehabilitation. Displacement and fracture of the restorations frequently occurred during the observation period for the function of the restorations. Therefore, the pre-endodontic post and core technique was applied to the abutment teeth before their endodontic treatments were started. The technique consisted of three steps as follows: Step 1: Caries removal and dowel preparation were performed for the abutment teeth having apical periodontitis. Composite cores were indirectly fabricated, which had access holes for endodontic treatment. Step 2: The cores were bonded to the teeth. In endodontic treatment, rubber dam appliances were easily placed owing to the core, and proper tooth isolation was accomplished. Step 3: Fiberposts were bonded to the dowel holes through the access holes after the root canal filling. During endodontic treatment, displacement and/or fracture of the provisional restorations did not occur. Conclusion The pre-endodontic post and core technique was effective in obtaining improved retention of provisional restoration, appropriate isolation for endodontic treatment, and sufficient retention of the post and core. Clinical significance The pre-endodontic post and core technique is useful for avoiding the discomforts in dental treatments, namely, a smooth transition from endodontic to prosthodontic treatment can be achieved.

Computed tomography (CT) scanning has recently been introduced into forensic medicine and dentistry. However, the presence of metal restorations in the dentition can adversely affect the quality of three-dimensional reconstruction from CT scans. In this study, we aimed to evaluate the reproducibility of a "high-precision, reconstructed 3D model" obtained from a conebeam CT scan of dentition, a method that might be particularly helpful in forensic medicine. We took conebeam CT and helical CT images of three dry skulls marked with 47 measuring points; reconstructed three-dimensional images; and measured the distances between the points in the 3D images with a computer-aided design/computer-aided manufacturing (CAD/CAM) marker. We found that in comparison with the helical CT, conebeam CT is capable of reproducing measurements closer to those obtained from the actual samples. In conclusion, our study indicated that the image-reproduction from a conebeam CT scan was more accurate than that from a helical CT scan. Furthermore, the "high-precision reconstructed 3D model" facilitates reliable visualization of full-sized oral and maxillofacial regions in both helical and conebeam CT scans.

The heterotrimeric CCAAT-binding complex (CBC) is evolutionarily conserved in eukaryotic organisms, including fungi, plants, and mammals. The CBC consists of three subunits, which are named in the filamentous fungus Aspergillus nidulans HapB, HapC, and HapE. HapX, a fourth CBC subunit, was identified exclusively in fungi, except for Saccharomyces cerevisiae and the closely related Saccharomycotina species. The CBC-HapX complex acts as the master regulator of iron homeostasis. HapX belongs to the class of basic region leucine zipper transcription factors. We demonstrated that the CBC and HapX bind cooperatively to bipartite DNA motifs with a general HapX/CBC/DNA 2:1:1 stoichiometry in a class of genes that are repressed by HapX-CBC in A. nidulans during iron limitation. This combinatorial binding mode requires protein-protein interaction between the N-terminal domain of HapE and the N-terminal CBC binding domain of HapX as well as sequence-specific DNA binding of both the CBC and HapX. Initial binding of the CBC to CCAAT boxes is mandatory for DNA recognition of HapX. HapX specifically targets the minimal motif 5'-GAT-3', which is located at a distance of 11-12 bp downstream of the respective CCAAT box. Single nucleotide substitutions at the 5'- and 3'-end of the GAT motif as well as different spacing between the CBC and HapX DNA-binding sites revealed a remarkable promiscuous DNA-recognition mode of HapX. This flexible DNA-binding code may have evolved as a mechanism for fine-tuning the transcriptional activity of CBC-HapX at distinct target promoters.

A 26-year-old female patient exhibited symptoms associated with egg allergy, which had been present since early childhood. The patient requested the treatment of egg allergy and was admitted to our hospital for rush oral immunotherapy. The threshold was determined by an oral food challenge test, after positive results on a double-blind food challenge test. The patient ingested dry powder of raw egg-white 5 times per day starting with a tenth of the threshold dose (3.0mg), followed by a 1.2-times increase every time. When the amount of powder reached 1g, it was replaced with 8g of scrambled egg, after then subsequent doses were increased 1.5 times every time. The target of one chicken egg (60g) was reached on the 18

Japanese–English bilinguals completed a masked phonological priming study with Japanese Katakana primes and English targets. Event related potential (ERP) data were collected in addition to lexical decision responses. A cross-script phonological priming effect was observed in both measures, and the effect did not interact with frequency. In the ERP data, the phonological priming effect was evident before the frequency effect. These data, along with analyses of response latency distributions, provide evidence that the cross-script phonological priming effects were the consequence of the activation of sublexical phonological representations in a store shared by both Japanese and English. This activation fed back to sublexical and lexical orthographic representations, influencing lexical decision latencies. The implications for the Bilingual Interactive Activation (BIA+) model of word recognition are discussed.

Bimetal nanoparticles of Pd Fe were deposited onto CeO2 by using dual arc-plasma to study their structures and catalytic properties for CO oxidation. Highly dispersed uniform nanoparticles with the average size of about 2 nm were successfully obtained. By synchronizing two pulsed arc-plasmas, single bimetal nanoparticles containing both Pd and Fe could be formed, but asynchronous pulsing yielded mixtures of each metal nanoparticle. In accordance with the structural difference, the Pd Fe bimetal nanoparticle on CeO2 was found to stabilize metallic states of Pd and Fe and therefore exhibited higher catalytic activities for CO oxidation. The same trend was observed after thermal ageing at 900 °C for 25 h in a stream of 10% H2O in air; Pd Fe/CeO2 prepared under the synchronous pulse condition showed the higher activity than Pd/CeO2 and asynchronous Pd Fe/CeO2 due to abundance of metallic Pd.

By applying a pulsed arc-plasma process, Pt nanoparticles were deposited from a Pt cathode onto CeO2 powders to study their structure and catalytic activity for CO oxidation. Highly dispersed unifo...

A地区における防災に関するニーズをもとに開催した防災講習会が住民の意識に与える影響および自主防災力を高めるための保健師の支援について検討した。地域の組織・団体へのインタビュー調査やA地区住民に対するアンケー結果をもとに、ニーズを反映した講習会を開催し、開催後にアンケートを実施した。各地域の組織・団体は「自主防災組織の発展」、「市や消防団との連携体制」を望んでいた。また、住民のニーズや防災講習会をとおして、①平均自立期間延伸のための取り組み、②住民組織間の連携の強化、③人材発掘、④ニーズの把握、⑤継続的かつ体験型の防災活動の実施等の保健師の支援が必要といえた。

A highly dispersed supported Rh catalyst was successfully prepared by an arc-plasma process for the first time and was characterized by means of TEM, XPS and EXAFS. Repeated generation of pulsed arc-plasma using a Rh rod as a cathode was found to deposit crystallized uniform metallic Rh particles with the size of 2.4 ± 1.1 nm onto the surface of AlPO4 powders. The metal-support interaction via Rh–O–P bonding in the catalyst prepared using arc-plasma was found to be weaker than in the catalyst prepared by conventional wet impregnation. The arc-plasma catalyst preparation achieved a higher CO oxidation activity because of highly dispersed metallic Rh nanoparticles.

The purpose of this present study was to improve student knowledge on the semi-adjustable articulator. Following from the insights provided by Ryan and Deci’s review of Organismic Integration Theory (OIT), we attempted to promote student interest in the semi-adjustable articulator. OIT was also utilized to provide guidance in assessing student motivation and its relation between the degree of student knowledge/interest. Finally, the study also aimed at establishing a rationale to evaluate and further develop our classroom practices at the institute. Through this process for raising student awareness, it was suggested that to observe the FGPs was useful to recognize the utility of a semi-adjustable articulator when a bridge at the molar region is made. Moreover, it was suggested that the student motivation helped promote their understanding. This highlights the need to support student motivation in our classroom. Finally, future studies on how professors perceive bureaucratic pressures from Ministry of Health, Labor and Welfare (MHLW) and within the institute could add additional insights to improving our educational practices in the classroom.

The previous reports suggest that obstructive sleep apnoea (OSA) is related to metabolic syndrome, mineral metabolism disorders and cardiovascular disease. In addition, a possible relationship between obesity and the calcification of ligaments has been implied. However, the potential link between OSA and the calcification of ligaments has not been directly studied. In this present study, to investigate the potential link between OSA and the calcification of ligaments, we examined the prevalence of the calcification of ligaments in OSA patients and the relationship between these findings and OSA severity. Eighty consecutive patients (60 males, 20 females) diagnosed as OSA or a heavy snorer based on full-night polyso-mnography were retrospectively recruited from May 2006 to July 2008. Each patient underwent cephalometric imaging examination before the arrangement of an oral appliance. One calibrated observer (YS) reviewed the cephalometric images for the presence of calcification of the nuchal ligament and osteophytes of the cervical spine. The prevalence of calcification of the nuchal ligament in OSA patients and snorers was 46.3% (males: 52%, females: 30%) There was a significant positive correlation between the severity of OSA (AHI) and the calcification of the nuchal ligament before and after adjusting for BMI. The prevalence of the calcification of the nuchal ligament in OSA subjects and snorers was higher than in previous studies with non-OSA subjects. In addition, it is suggested that the severity of OSA correlates with the presence of calcification of the nuchal ligament.

PURPOSE The 4-dimensional human body model that combines reconstructed 3-dimensional image data (CT and MRI) and exercise data of the human body is widely applied in the medical field. We have applied this technique to assess mandibular movement, particularly in dentistry, and developed a 4-dimensional system of analyzing mandibular movement. The aim of this study was to determine the accuracy of this analysis system. METHODS A dry skull mandible was fixed at several mandibular positions and the skull-mandible relationship was measured at each position by two procedures: CT scanning was performed and a 3-dimensional image was reconstructed from image data that were regarded as true values; then, optical measurement markers attached to the dental arch were measured 3-dimensionally and calculated as positional measurement values. The measurement values were compared with the corresponding true values to identify measurement errors of the analysis system. RESULTS The root-mean-square (RMS) errors of the 4-dimensional analysis system of mandibular movement were, on average, 0.41 mm and 0.43 degrees. CONCLUSIONS These findings suggest that our 4-dimensional analysis system has sufficient measurement accuracy for mandibular movements.

The purpose of this study was to observe the variations of cervical curvature in patients with infraocclusion, and to compare this with the controls. In this study, the infraocclusion criteria were defined with the Pr-id as

Purpose: There has been a significant number of malocclusion patients who suffer from the osteoarthritis associated with TMJ, and acquired anterior open bites were reported as a representative example. Treatments for patients with malocclusion often prove difficult, as the condyle position is not stable. It remains unknown as to whether this is due to the disease or the condyle position. This case report documents a clinical application of a Digital Gothic Arch Tracer for occlusal diagnosis and subsequent management and treatment of malocclusion with osteoarthritis.Materials and methods: This case report presents the treatment process of a female patient (51 years, 6 months of age) with an acquired dual-bite malocclusion with severe osteoarthritis in the temporomandibular joint (TMJ). The occlusal condition of the patient was examined by a Digital Gothic Arch Tracer (DGAT, Gothic Display: Shofu Inc.). The GDAT was used as it provides an extra-oral tracing of jaw movements. While it is simple and easy to use, the accuracy remains impressively high, as several jaw motions are included into the final calculation.Results: The ensuing treatment plan was as follows: Upon the first examination, the occlusal position was recorded with DGAT. The DGAT data was then evaluated for correlations between the terminal points of the rapid habitual opening-closing movements (tapping points), apex point and speaking position. The gothic arch figure revealed that when approaching the terminal points of the tapping points and the speaking position, there was a separation at the apex point. From this, we reached a conclusion on the new occlusal position for tapping points and the speaking position. Based on the DGAT results, via the occlusal adjustment method, we set the new occlusal position. On their final visit the patient received Prosthodontics treatment. The DGAT was able to provide an avenue of examination that maintained the original occlusal position without raising the vertical dimension. Therefore, it was rather simple and exact to compare the Tapping points and Apex points.Conclusion: Using a Digital Gothic Arch Tracer, we successfully carried out the occlusal examination and treatment of a patient with osteoarthritis and malocclusion.

The new bitter diterpenes, rabdosianone I (C20H24O5) and II (C22H28O6), were isolated from Isodon japonicus (Japanese name, enmeiso), and their structures were elucidated by spectroscopic methods. Electrophysiological experiments were performed to compare rabdosianone I with quinine. The taste responses of chorda tympani nerves to rabdosianone I were smaller than those to quinine in Wistar rats.

Purpose Occlusal plane inclination is important to maintain a normal opening closing/biting function. However, there can be several causes that lead to alterations of the occlusal plane. The purpose of this study was to observe variations of occlusal plane inclination in adult patients, and to uncover the factors affecting changes in occlusal plane inclination with aging. Methods Subjects were 143 patients. A cephalometric image was taken of these patients. In this study, our inquiry points were age, 3 variables on intra-oral findings, and 7 variables on cephalometric analysis. To evaluate the possible causes that affect occlusal plane inclination, factor analysis was carried out, and each component was treated as factors, which were then statistically applied to a structural equation model. Statistical analysis was carried out through the SPSS 20.0 (SPSS Inc., Chicago, USA). Results In all patients, Camper-occlusal plane angle (COA) ranged from −25.7 to −4.9° (Mean±SD: −6.4±5.36). In the 60 patients who had no missing teeth, COA ranged from −11.6 to −4.9° (Mean±SD: −3.3±3.31). From the results of the structural analysis, it was suggested that the occlusal plane changes to counter-clockwise (on the right lateral cephalograms) with aging. Conclusion In this study, variations of occlusal plane inclination in adult patients were observed, and the factors affecting changes in occlusal plane inclination with aging were investigated via factor analysis. From our results, it was suggested that the mandibular morphology change and loss of teeth with aging influence occlusal plane inclination.

The purpose of this present study was to investigate the influence of material filler and RGB values' fluctuation on creating a calibration curve, which indicates the relationship between material thickness and transmitted light brightness using the transillumination method. Creating the calibration curves were carried out through the following three methods; 1) the conventional method creates the calibration curve with a formula of thickness, 2) the maximum value method, with samples of a specified thickness, and 3) the actual value method, with a microscope. Furthermore, the reliability of each curve was verified via scanned artificial tooth data. In addition, the characteristics of light decrement were investigated. From our results, it was suggested that the filler diameter must be considered when the calibration curve is created using the bite impression material with a filler. In addition, it was suggested that the RGB values' fluctuation did not influence the calibration curve.

Oral appliance (OA) therapy for obstructive sleep apnea (OSA) has only been part of Japan's National Health care coverage plan since 2004. Subsequently, not enough time has passed to establish the medical trends and characteristics of OSA patients in Japanese Dental Hospitals.The aim of this study was to investigate the medical trends and the characteristics in patients with OSA who visited our clinic, and to compare our findings with previous studies.Epidemiological survey (retrospective study).Two hundred and one patients were recruited at the Internal Medicine Division in the Tsurumi University Dental Hospital from February 2006 to December 2008, consecutively. Patients received a medical interview, and a detailed sleep analysis that included a polysomnography (PSG) to verify the exact nature of their condition. The efficacy of OA was assessed in 49 patients who wore an OA and underwent PSG.Of all subjects, 141 patients visited the Prosthodontic Division to receive OA therapy, 38 patients were treated or received a follow up examination in the Internal Medicine Division. The dropout rate was 10.4% in the all subjects, 17.0% in patients who visited the Prosthodontic Division. The male-to-female ratio was 3.3:1, 3.0:1 in patients who visited the Prosthodontic Division. In addition, females had a lower rate of OAS severity than males. In our patients, the major complication was hypertension and cardiac disease. The success rate of OA was 75.5%.This approach allowed us to reveal some of the trends and characteristics in our patients.

When asthmatic patients present with cough, especially cough without wheezing, it is difficult to determine if the cough was due to asthma. A 7-year-old girl presented with persistent cough without wheezing and exacerbation of asthma. We performed bronchodilator reversibility test by determining the respiratory resistance. Respiratory resistance and impedance were measured by using the Forced Oscillation Technique (FOT) with MostGraph-01 (Chest CO., LTD., Japan). The changes were observed in colored 3-dimensional imaging patterns. The images clearly showed that the patient’s respiratory resistance decreased after administration of the bronchodilator. The measurement of respiratory impedance by the forced oscillation technique attributes to diagnose asthma.

Services such as sending a pre-crash sensing warning and traffic condition warning are expected to be provided in car-to-car/infrastructure (C2X) communication systems. Maintaining message integrity is essential for these services because wrong messages may cause collision accidents and congestion. A message authentication code (MAC) generated by using a symmetric key is used to authenticate a message. The sender and receiver of a message must possess the same symmetric key before initiating communications. In the mentioned warning services, the sender of a message cannot know who receives the message, because the message is broadcast. Moreover, it is difficult for a road-side unit (RSU) to distribute a key to an onboard unit (OBU) because an OBU cannot always communicate with a RSU. Therefore, key distribution is a problem in C2X communication systems. We thus propose a protocol for key distribution. In the protocol, all OBUs and RSUs that exist in a certain area possess the same key. An OBU obtains the keys for the area in which the OBU is present and for the area to which the OBU will go next. The protocol enables a vehicle to verify message integrity by using a symmetric key in C2X communication systems.

For successful occlusal reconstruction, the prosthodontists must take several points into consideration, such as those involving issues with functional and morphological findings and aesthetics. They then must unify this information into a coherent treatment plan. In this present study we focused on prosthodontic treatment and investigated how treatment planning and simulation could be applied to two cases. The personal occlusion condition can be reproduced on the virtual articulator in VR space. In addition, various simulations can be performed that involve prosthetesis design.

Purpose Currently, over 40 different types of oral appliances (OA) are available to dentists to treat sleep disordered breathing. OA can be classified by mode of action or design. One of the major categories is tongue retaining device; the other is a mandibular advancement device (MAD). Each device, however, has its own particular drawbacks, the most common revolving around cost or inherent difficulties in the production process.In this present report, we will introduce a “movable” OA which does not disturb the physiologic function. This approach utilizes novel connectors that are both low in cost and involve a straightforward production procedure. Methods Our device is categorized as a MAD. The design of the appliance followed that of the cap clasp, and the undercut was set at 0.25 mm. The polyester sheet was pressed to casts via a pressure molding machine, and cut along the design line mentioned above. In our device, we converted a Co–Cr wire as a connector for the OA. From this we developed and applied 2 new connectors for the clinical setting that were low in cost and allowed for mandible movement. These are lingual-side and labial-side types. In this present study the rate of success was 75.5%; with a good response classified as an AHI with less than 5 events/h, or a 50% decrease in their pre-treatment AHI. The efficacy of our OA was equal to previous studies. Conclusion In this present report, we could propose inexpensive novel connectors which do not disturb the physiologic function.

Objective The aim was to report the kinetics of masticatory muscles using a 4-dimensional muscle model and kinetically investigate the etiology of square mandible (SQM) in vivo. Study design To ascertain the mandibular movements in patients with SQM, we compared a group of 11 SQM patients with painless limited mouth opening to a matched group of 11 healthy volunteers who acted as control subjects. Mandibular movements were recorded using a 6-degrees-of-freedom jaw-tracking device, with the incisal and kinematic condylar as analytic points. Results For the control group, mean tracking distance for the incisal point was 50.1 ± 6.8 mm, whereas for the SQM group mean tracking distance was 27.1 ± 2.8 mm. With lateral excursions, the control group's mean tracking distance of the incisal point was 9.9 ± 2.01 mm, and the SQM group's was 8.1 ± 1.64 mm. Conclusion Despite a sufficient lateral excursion, motion of the mandible was limited by some factors at opening and suggests that the mode of lateral movements in SQM patients may differ slightly from those in healthy individuals.

PURPOSE: A jaw motion tracking device that measures six degrees of freedom has recently been developed. Understanding jaw motion is useful, but previous measurement methods were impractical for use in dental clinics. The overall aim of this study was to demonstrate the simple operation, low cost, and high precision of a recently developed jaw tracking device. In addition, this study explored its potential clinical applications. METHODS: In this study, we compared two jaw motion tracking devices: a digital system type of device and an optical type of device. First we established a baseline occlusal plane from which to measure jaw motion in the same subject with both devices. The jaw motion signals were sampled at a frequency of 100 Hz. The subjects were three healthy women (mean age +/- SD = 26.3 +/- 1.2 years) who were recruited from among the crown-and-bridge faculty of Tsurumi University of Dentistry. The jaw motions measured were open-close movement, sagittal border movement, and frontal border movement. In addition, the kinematic axis point was calculated from the sagittal border movement. Data from the digital system type of device and data from the optical device were compared. The data were selected to measure rotation and translocation, i.e. jaw position about protrusion, both laterotrusion and maximal opening of the mouth. RESULTS: The root mean square (RMS) error of position measurement was 0.163 mm with MM-JI-E and 0.178 mm with the optical type of device. The RMS error of jaw motion measurement with the optical type of device was maximum at 0.8mm and minimum at 0.1mm. This was similar to that with digital system type of jaw motion tracking device. CONCLUSION: This study showed the possibility of developing clinical applications for this jaw motion device.

Purpose The purpose of this study was to determine whether rotation and translation of the condyle were useful parameters for identifying causes of limitation of mouth opening in patients with temporomandibular disorders (TMD). Methods In 7 healthy volunteers and 55 patients with TMD, rotation and translation of the condyle were measured using a 6 degree-of-freedom jaw movement tracking device. Patients were divided into two groups: those who could open their mouth 40 mm or greater, and those who could not open their mouth 40 mm. In each group, the relationship of rotation and translation of the condyle to maximum mouth opening, condition of the articular disc, and pain was determined. Results Both correlations between maximum mouth opening and rotation and translation of the condyle were strong, especially the former correlation. There was no marked difference in the distribution of range of mouth opening, and rotation and translation of the condyle with respect to condition of the artticular disc. Muscle pain was associated with reduced mouth opening. Even in patients without limited mouth opening, their range of mouth opening was actually reduced when they had muscle pain. Among the patients with limited mouth opening, joint pain correlated to limited translation of the condyle. However, in patients with Wo-Wo condition of articular disc, their translation of the condyle was not limited even with joint pain, but it was limited with muscle pain. Conclusions Rotation of the condyle indicated strong correlation with muscle pain, and so is a useful parameter for estimating treatment methods by a surgical approach. On the other hand, translation of the condyle showed variations in correspondence with combinations of several factors such as opening limitation, condition of the articular disc, and pain.

The present study was conducted to ascertain characteristics of mandibular movements in patients with SQM, observe the kinetics of masticatory muscles using a four-dimensional (4D) muscle model, and kinetically investigate the etiology of Square Mandible (SQM). As results, 1, In the maximum opening position, location of the condyle was beyond the articular tubercle for volunteer, but within the mandibular fossa for SQM patient. 2, While the temporal muscle of volunteer was markedly expanded, that of SQM patient was not. 3, In both volunteer and SQM during left lateral excursion, the right mandibular condyle moved to a position slightly before the lowest point of the articular tubercle. The 4D muscle model showed that the cause of limited mouth opening in SQM patient was insufficient expansion of the temporal muscle, and not dysfunction of the opening muscles. Insufficient expansion of the temporal muscle stresses the masseter muscle and leads to hypertrophy of the masseter muscle and hyperplasia of the mandibular angle, resulting in the unique facial configuration.

外傷性咬合と歯槽骨吸収形態との関連性について検討したいために, 画像解析装置を用い, 外傷性咬合の検討は, 外傷性咬合時の咬合力の大きさと咬合力の加わる方向を指標にした。また被験歯は, 早期接独があってわれわれが規定した一定の条件を満たした下顎の臼歯21歯を対象にした。観察の結果は,1. SHonic-GAシステムを用い規格デンタルX線写真を画像処理し, まず臼歯の歯槽骨吸収形態を小臼歯は4種に大臼歯は5種に分類した。2. 小臼歯では, 歯槽骨の吸収域に一致して, 早期接触, OCAおよびLG1° が認められた。3. 大臼歯のI型とII型では, 歯槽骨の吸収域に一致して, OCAとLC1° が認められることが多く, 歯槽骨吸収形態との関連性が示唆されたが, III型とIV型では認められなかった。4. 早期接触部と, 各歯の最大OCAおよび最大LG1° の部位が一致して認められた。