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We investigated the changes in lip and cheek movements involved in smiling, recorded before and after surgical orthodontic treatment for mandibular protrusion with mandibular deviation (MPD), and compared the obtained data with those of individuals with normal occlusion (NO). The study enrolled 8 individuals with NO and 8 patients with MPD who underwent surgical orthodontic treatment at the Matsumoto Dental University Hospital. The lip and cheek movements of individuals were analyzed three–dimensionally using stereo images, and their frontal and lateral craniofacial morphologies were assessed using posterior–anterior and lateral cephalograms. Pre–treatment assessment of lip movements in MPD patients showed that the corner of mouth (CM) on the non–deviated side exhibited a significant increase in upward move ment and decrease in lateral movement, as compared to the deviated side. However, the comparison of these results with those of individuals with NO revealed that the lateral and posterior movement of the CM on the non–deviated and deviated sides, respectively, was significantly lesser in patients with MPD than in individuals with NO. Post–treatment assessment of lip movements showed an increase in the lateral and the upward movement of the CM on the non–deviated and deviated side, respectively, indicating the successful correction of asymmetrical CM movement. However, the posterior movement in the CM on the deviated and non–deviated sides in the patients with MPD were significantly lesser than those in individuals with NO. Furthermore, a comparison of the absolute values of three–dimensional movements recorded between the center of the upper and lower lips revealed no significant difference in pre– and post–treatment movements. On the contrary, post–treatment movement of the center of the lower lip in the posterior direction was significantly lesser in patients with MDP than individuals with NO. The three–dimensional movement of the cheek did not show significant difference between the deviated and non–deviated sides before and after treatment. However, the anterior movement of the cheek on the non–deviated side in the individuals with MPD increased significantly after treatment. There were no significant differences in the three–dimensional movement of cheek among individuals with MPD, before and after treatment, and in the individuals with NO. In the present study, the asymmetrical three–dimensional movements of CM involved in smiling, between the deviated and non–deviated sides in the individuals with MPD, were corrected after surgical orthodontic treatment. However, the post–treatment movements in the individuals with MPD were different from those in individuals with NO.

Clinical and statistical analyses were conducred of patients with jaw deformity who visited the Department of orthodontics, Matsumoto Dental University hospital. One hundred and two patients with jaw deformity were treated in the department from January 2003 to December 2012. (1) The total number of patients was 102; the male–female ratio was 1: 1.32. (2) Mandibular protrusion was the most frequent diagnosis, with 35 cases (34.3％), followed by mandibular protrusion + maxillary retrusion (16 cases, 15.7％), and mandibular protrusion + asymmetry (15 cases, 14.7％). (3) As for the tooth extraction sites for presurgical orthodontic treatment, although non–tooth extraction was the highest from 2003 to 200₇, maxillary first premolar tooth extraction was the highest from 2008 to 2012. (4) Sagittal split ramus osteotomy (SSRO) was the most commonly performed procedure (5₇.8％), followed by Le Fort I + SSRO (36.3％). Le Fort I + SSRO showed an increasing tendency.

The aim of this study was to develop a method for integrating morphological coordinates obtained with dental computer tomography (CT) and jaw movement coordinates acquired with a mandibular movement measuring device in order to enable multipoint analysis of anatomical condylar movements to be performed. The study subjects were two volunteers. One of the subjects displayed mandibular deviation and had a deformed condyle (on the deviated side), while the other subject exhibited normal occlusion and had healthy condyles. We placed three lead markers in front of each of the subjectsʼ ears and used them to integrate dental CT–derived morphological volume data and jaw movement data, both of which were obtained while the subjects were in the same seated position. Regarding the reproducibility of the reference point data, the positioning and orientation data obtained with the condylar movement measurement system exhibited maximum standard deviation values of 0.162 mm and 0.0₇4°, respectively, while the equivalent data acquired with the CT coordinate system displayed maximum standard deviation values of 0.068 mm and 0.00₇°, respectively. This suggested that reference point errors had little effect on our multipoint analysis of anatomical condylar movement and that the method used to transform the CT coordinates was highly precise. These results indicate that our method for integrating dental CT–derived coordinates with those acquired using a condylar movement measuring device leads to minimal errors in the positional/rotational data for the reference markers and hence, facilitates multipoint analyses of anatomical condylar movement.

Facial reconstruction is a technique that allows human skeletal remains to be used to build a facial image of the target individual during life. This technique is based on databases of facial soft tissue thickness. However, application of this technique is facilitated by accurate information such as age, sex and ancestry. Little information is available from the skull alone for building face reconstructions, particularly for skulls from juveniles. This study estimated sex differences from the cranial bases of juvenile skulls and observed significant differences between male and female in the S-N plane for Japanese children at 6-to 18-years-old.

The purpose of this clinical research was to examine the racial differences in skeletal morphology of skeletal Class III abnormalities and in the ortho-surgical treatment outcome of Class III malocclusion associated with mandibular setback sagittal osteotomy between Japanese and British Caucasian female adult Class III patients. The sample consisted of 35 Class III Japanese female surgical subjects in MDU Hospital and 30 Class III British subjects (23 female and 7 male). The operative procedure was solely a backward sliding sagittal split osteotomy with a wire fixation. True skeletal open bite cases associated with high mandibular plane angle were excluded. The original skeletal differences in Japanese and British Caucasian Class III subjects showed a significant difference in the length of the anterior cranial base (S-N) (p

Available studies about differences among races, related to prevalence of malocclusion or morphology of head and dental arches, suggest a hypothesis that the high prevalence of skeletal Class III malocclusion in Asian ancestry populations could be correlated with a tendency toward a brachycephalic head form and larger arches widths. The purpose of the present study was to evaluate anteroposterior relationship of upper and lower jaws associated to form of dental arches, maxilla, mandible, face and head. Materials in this research consisted of pretreatment lateral and posteroanterior cephalometric radiographs and orthodontic models of Japanese females with skeletal Class I and Class III. Strong correlations between head form and jaws anteroposterior relationship could not be found. However, results indicated that skeletal Class III have statistically significant smaller length of maxilla and greater length of mandible, than the skeletal Class I group. Moreover, basal arch length and width of mandible were significantly bigger in skeletal Class III group. These results suggest that skeletal Class III, at least in this sample, might be associated to local malformation factors.