Toru Kageyama

Pilot study of facial soft tissue thickness differences among three skeletal classes in Japanese females

Facial reconstruction is a technique used in forensic anthropology to estimate the appearance of the antemortem face from unknown human skeletal remains. This requires accurate skull assessment (for variables such as age, sex, and race) and soft tissue thickness data. However, the skull can provide only limited information, and further data are needed to reconstruct the face. The authors herein obtained further information from the skull in order to reconstruct the face more accurately. Skulls can be classified into three facial types on the basis of orthodontic skeletal classes (namely, straight facial profile, type I, convex facial profile, type II, and concave facial profile, type III). This concept was applied to facial tissue measurement and soft tissue depth was compared in each skeletal class in a Japanese female population. Differences of soft tissue depth between skeletal classes were observed, and this information may enable more accurate reconstruction than sex-specific depth alone.

Facial soft tissue thickness in Japanese children

Facial reconstruction techniques used in forensic anthropology are based on mean soft tissue thickness measurements. Numerous studies of facial tissue thickness in adults have been published on a range of subjects from different ancestral backgrounds. Data on facial thickness in children derive primarily from Caucasoid, African-American, and Hispanic subjects. There are limited data from the few studies of Japanese children (male: skeletal class I only; female: all skeletal classes). The author has previously reported facial tissue thickness data for Japanese girls and boys with skeletal class I and for all three skeletal classes in Japanese girls. The present study reports facial soft tissue thickness data in Japanese children of all skeletal classes, within age subsets. With parental informed consent, diagnostic lateral cephalometric X-ray images were obtained from 339 Japanese children aged 7-18 years (male: 162; female: 177) who attended the Matsumoto Dental University Department of Orthodontics to undergo orthodontic treatment. Soft tissue and skeletal features were traced onto acetate sheets from the X-ray images, and 10 anthropological landmarks on the midsagittal line were measured. Means, SDs, and ranges were then calculated. Differences between male and female measurements in six age groups were compared using t-tests. Significant differences were observed at some landmarks in each age group. The findings were compared with data from other juvenile populations.

Autotransplantation of 28 premolar donor teeth in 24 orthodontic patients.

OBJECTIVE To test the null hypothesis that premolar autotransplantation is not successful for orthodontic patients. MATERIALS AND METHODS In the present study, 28 premolar transplants from 24 orthodontic patients were associated with orthodontic treatment. At a routine 3-month appointment, patients underwent a dental radiograph and a chair-side observation for periodontal problems. Three sets of dental radiographs were taken by one dental assistant using a custom holder at: preoperation (T0), 2 year postoperation (T1), and retention (T2) (4- to 14-year follow-up observation) stages. All transplants were conducted in a one-phase operation by one operator (Dr Inoue). Recipient sites were: ten for missing maxillary canines, nine for maxillary centrals and laterals, eight for lower second premolar, and five for other missing premolar sites. All recipients maintained the retained primary tooth with a socket. RESULTS The success ratio of all 28 transplants was 100%, although four transplants shorter than a 4-year period of observation were omitted. Two transplant patients, one with a medical history of histiocytosis and the other with a history of osteomyelitis of the maxilla without a recipient socket, were also excluded from this study. Eleven of 22 premolar transplants had a root canal treatment (RCT), four of which had RCT within 2 years after the operation. CONCLUSIONS The null hypothesis was rejected. The success ratio of premolar transplants was 100%.

Facial soft tissue thickness differences among three skeletal classes in Japanese population

Facial reconstruction is used in forensic anthropology to recreate the face from unknown human skeletal remains, and to elucidate the antemortem facial appearance. This requires accurate assessment of the skull (age, sex, ancestry, etc.) and thickness data. However, additional information is required to reconstruct the face as the information obtained from the skull is limited. Here, we aimed to examine the information from the skull that is required for accurate facial reconstruction. The human facial profile is classified into 3 shapes: straight, convex, and concave. These facial profiles facilitate recognition of individuals. The skeletal classes used in orthodontics are classified according to these 3 facial types. We have previously reported the differences between Japanese females. In the present study, we applied this classification for facial tissue measurement, compared the differences in tissue depth of each skeletal class for both sexes in the Japanese population, and elucidated the differences between the skeletal classes.

Assessment of the esthetic smile in young Japanese women

Abstract Introduction The aim of the present study is to evaluate an esthetic smile in young Japanese women, which is not yet clear. Materials Thirty orthodontically treated female patients formed Group 1 and the same number of female models, Group 2. Methods All smile photos and slides were digitalized for analysis in an image-processing program. As the photos in Group 2 had a different size, the output image size was not considered. Five visual and four quantitative evaluations of a smile were studied for each subject. The smile arch and index, buccal corridor spaces (BCSs) and relationship between BCS and maxillary dental arch widths were studied. Statistics Standard errors of the measurements were calculated. Independent students t-tests were used to compare statistically the measurements of Group 1 patients and Group 2 model samples, and also those of BCS and the widths of the upper dental arch (UAW). Mean and standard deviation were calculated and p < 0.05 was significant. Results and conclusion The average smile, smile curve arch line without touching the lower lip, parallelism of the upper incisal curve with the inner curvature of the lower lip, no display of the 1st molar, 1:1 ratio of the widths of nose and upper cuspid, a minimum buccal corridor with no significant relation in widths of the upper dental arch all corresponded to ideal smile.

Chin Cup Treatment Outcomes in Skeletal Class III Dolicho- Versus Nondolichofacial Patients

This study examines cephalometric differences and sex differences in the long-term outcome of chin cup treatments of Class III subjects with two facial patterns. Seventeen nondolichofacial and 16 dolichofacial Class III male patients and 16 nondolichofacial and 16 dolichofacial female patients were treated by either bicuspid extraction or nonextraction. Rapid palatal expansion without maxillary protraction was performed on 11 male cases and 15 female cases. The borderline between the two groups was drawn either at 39 degrees mandibular plane angle or 132 degrees (male subjects) or 130 degrees (female subjects) gonial angle. Dolichofacial subjects were treated with either an occipital or a high-pull chin cup force during the first two years, followed by high-pull force during night-time wear for the subsequent three years. All treated cases showed excellent results in the retention records with acceptable posterior occlusion as well as excellent skeletal and soft-tissue profiles. In addition, patient compliance was excellent. The treatment outcomes of the two groups showed significant improvement of the skeletal Class III malocclusion. This study indicated that the treatment period and wear time of the chin cup appliance in nondolichofacial (mostly mesiofacial pattern) patients could be shorter than those of dolichofacial patients. Although all subjects showed significant improvement in the Class III malocclusion, the treatment outcome in the two groups maintained the original characteristic skeletal morphology at retention.

Estimation of nasal tip position using lateral cephalometric X-ray images in Japanese male children : Applications in facial reconstruction

Abstract Facial reconstruction is a forensic anthropological technique based on a database of facial soft tissue thickness; however, the information available is generally insufficient to completely reconstruct facial features. While most soft tissue in the craniofacial region is strongly adherent to the bony surface, a few areas, such as the ears, nose, and lip regions, are not. Yet these are vital features for forensic identification and are used in everyday life in facial recognition. For such features, forensic anthropologists investigating age, sex, ancestry, and facial appearance must often rely upon bony information alone. Determination of nasal tip position in adults from the skull has been reported by several researchers. However, data for determining nasal tip position from the juvenile skull have not been reported. The aim of this study was to establish and apply a simple discriminative method of identification of nasal tip location in unidentified juvenile human skeletal remains through an investigation of the cranial base in the current Japanese juvenile population. The result would be applicable for not only the research described above but also estimation of growth of mid facial profile (i.e. estimation of patterns of bony and cartilaginous framework of the nose by diseased palatal clefts etc.) and aesthetic standards. Lateral cephalometric X-ray images were used to measure soft tissue thickness in subjects undergoing orthodontic treatment. Two reference planes were set on the skull radiograph (one had already been set at the beginning of facial reconstruction). After tracing the facial profile and plotting soft tissue and bony landmarks, nine dimensions of distances (length and length ratio) and angles between these landmarks and the nasal tip were measured. A prediction function for the nasal tip was derived from these measurements. This study reports a simple and reliable method of nasal tip prediction for use in forensic facial reconstruction from incomplete human juvenile skulls.

Pilot study to establish a nasal tip prediction method from unknown human skeletal remains for facial reconstruction and skull photo superimposition as applied to a Japanese male populations

Skull-photo superimposition is a technique used to identify the relationship between the skull and a photograph of a target person: and facial reconstruction reproduces antemortem facial features from an unknown human skull, or identifies the facial features of unknown human skeletal remains. These techniques are based on soft tissue thickness and the relationships between soft tissue and the skull, i.e., the position of the ear and external acoustic meatus, pupil and orbit, nose and nasal aperture, and lips and teeth. However, the ear and nose region are relatively difficult to identify because of their structure, as the soft tissues of these regions are lined with cartilage. We attempted to establish a more accurate method to determine the position of the nasal tip from the skull. We measured the height of the maxilla and mid-lower facial region in 55 Japanese men and generated a regression equation from the collected data. We obtained a result that was 2.0±0.99mm (mean±SD) distant from the true nasal tip, when applied to a validation set consisting of another 12 Japanese men.

Morphological Changes in the Temporomandibular Joint Before and After Sagittal Splitting Ramus Osteotomy of the Mandible for Skeletal Mandibular Protrusion

Abstract Changes of temporomandibular joint (TMJ) morphology were analyzed in 21 patients with mandibular protrusion corrected using bilateral sagittal split ramus osteotomy (SSRO) and mini-plate fixation with TMJ cephalometric laminographs. The condylar pass angle, eminence to the FH plane angle, and total height of fossa and lower height of fossa in both left and right sides, significantly decreased after surgery. The width of the condyle, in both left and right sides, significantly increased after treatment. However, in the joint spaces, there were no significant differences before and after treatment. The amount of change in the eminence to the FH plane angle, total height of fossa and lower height of fossa, before and after surgery, showed significant positive correlations with that of SNB, before and after surgery. These results suggest that adaptive bone remodeling of the TMJ might occur due to the correction of occlusion and craniofacial morphology by SSRO in patients with mandibular protrusion.

The aggressive chin cup protocol (14 h/day for 2 years with excellent compliance) depends on commitment to overcorrection of the skeletal Class III malocclusion

Abstract The effects of 2-year orthopedic treatment with a chin cup appliance were compared between: Group 1, 35 female patients from a private clinic who showed excellent compliance; Group 2, 31 female patients from a dental hospital, whose compliance ranged from good to fair; Group 3, an untreated control sample of similar female patients. All patients had anterior cross-bite and a negative ANB angle of at least −2°. The first group was treated with an aggressive protocol: 14 h a day for 2 years, force of 250–300 g, frequent monitoring to ensure compliance for the full 2 years and commitment to overtreatment of skeletal Class III malocclusion to improve stability. The second group was treated with a more routine protocol: night-time wear for 2 years, force of 500 g, commitment to correcting the anterior cross-bite (year one) with compliance tapering off in the second year. The third group was a cross-sectional sample of untreated females with similar Class III malocclusions. Group 1 showed significantly more skeletal correction. It was concluded that an aggressive protocol of chin cup therapy for 2 years is an orthopedic solution for developing Class III malocclusions.