There are many methods of measuring facial configurations, and in recent years, reports and clinical studies on three-dimensional analysis have increased. Especially, the 3D optical scanning system offers not only rapid high-precision measurement but also no radiation exposure.
We have newly developed a non-contact 3D optical scanning system (SURFLACER VMH-300F) which is equipped with cephalostats, and investigated the reliability, accuracy and stability of locating specific landmarks on facial soft tissue. We measured and analyzed the facial configurations of 10 adult Japanese, 5 times per subject, using this system and reverse engineering software (Imageware 9).
The results were as follows.
1. The operation of rectifying a position could be reduce the error to 0.63±0.15mm.
2.High-precision Measurement could be performed by using cephalostats, without rectifying a position. However, rectifying increased the accuracy.
3. The meanerrorof the measurement datum point was 2.68±0.89mm, the datum point of the foreheadarea had high reproducibility, and the datum point of the angle of mouth and angle of mandible had low reproducibility.

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Mandibular retrusion results from abnormal positioning of the condylar head brought about by habitual occlusion. Pressure from muscles of the tongue and oral aperture make it difficult to achieve post-operative stability of the mandible head in orthognathic surgery. The purpose of this study was to evaluate the post-operative stability of the mandible under specific conditions.
We improved the operative method to be employed and controlled the mandibular position both before and after surgery.
The subjects consisted of 19 patients who underwent sagittal splitting ramus osteotomy. None of the subjects had asymmetry or open bite. Regarding surgical settings, we assumed the front teeth to be edge to edge andset the occlusion space in the first molar at approximately 1.5mm. The proximal segment was in contact with the distal segment, and a total of 3 lug s rews wereput into position. Surgical and post-operative changes were measured cephalometrically.
Radiographs were taken pre-operatively, at fixation, and then at 1, 3, 6 and 12 months after surgery. Ricketts analysis was used in tracing and analyzing the graphs (22 reference points).
One year following surgery, the mandibular body had rotated clockwise and was in a posterior direction. Over bite increased, and space closure between molars was complete at approximately 3 months after surgery.
Over-correction disappeared within 3 months of surgery.
The mandibular position stabilized suggesting that the new gnathic mandibular position and occlusion achieved would allow for improved function.

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The purpose of this study was to develop posterior-anterior cephalometric standards for Japanese adult males and females. The subjects evaluated in the study included 138 males with a mean age of 21.3 years and 69 females with a mean age of 21 years. All individuals in this study had normal occlusion, no apparent facialasymmetry and none had undergone orthodontic or orthognathic therapies. We chos 11 points in their posterior-anterior cephalograms. Distances and angles betweenthese points were measured and analyzed statistically with the t test. We developed a five-cornered criteria figure (pentagon) which is used as a standard parameter of facial symmetry. Two pentagons were made for males (upper and lower jaws) and two for females (upper and lower jaws), and the Pentagons of both males and females were compared. The upper face in males was wider than in females. Also, the males had a higher facial height than females due to the difference in ramus height. Both males and females showed no significant differences in angular measurements.
Conclusion: This criteria figure (pentagon) can be used as a reference standard for diagnosis of patients with various facial asymmetries. It can also be used for evaluation of treatment goals and informed consent.

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Aim: The purpose of this study was to evaluate the longitudinal changes of TMD symptoms following orthognathic surgery.
Material and methods: Questionnaires of 100 patients with jaw deformities (60 females and 40 males, mean age of 21.2 years old) taken at four stages: pre-treatment, just before surgery, post treatment, and under retention (mean retention term of 3.1 years) were used to evaluatelongitudinal changes of TMD symptoms. The answer for each question including noise, pain and difficulty in jaw movement was scored (TMD score): one point for “yes” and zero point for “no”. Based on the reported symptoms before treatment, patients were divided into two groups: symptomatic group andasymptomatic group. Thesymptomatic group was subdivided into the following threegroups according to severity of TMD symptoms: 1) Mild type group (TMD score: 1), 2) Moderate type group (TMD score: 2), 3) Severe type group (TMD score: 3).Increaseordecrease of the score in the two groups was evaluated during the presurgicaltreatment, post-surgical treatment, retention and whole treatment, respectively.Furthermore, potential etiologic factors such as age, gender, treatment term, type of malocclusion, surgical method, tooth extraction and change of overbite and overjet were statistically anaanalyzed for association with the changes in TMD symptoms.
Results: Seventy-one patients out of 100 were symptomatic patients and 29 were asymptomatic patients. During the whole term, 49.3% of the symptomatic group showed a decreaseof the score, 9.9% an increase of the score and 40.8% no change of the score. Onthe other hand, 20.6% of the asymptomatic group showed an increase of the score and 79.4% no change of the score. At each term in the symptomatic group, the severe type group showed a larger decrease of the score than themoderate and mild type groups. Significant differences were also found in the change of individualTMD symptoms between the symptomatic and asymptomatic groups at each term. No statistically significant relation was found between potential etiologic factors and the change of TMD symptoms.
Conclusions: Significantly different aspects were recognized in the change of TMD symptoms between the symptomatic and asymptomatic groups.In the symptomatic group, frequency of TMD improvement became higher in inverse proportion to the severity of TMD, but etiological factors causing TMDwere not recognized.

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The purpose of this study was to compare changes in soft tissue with those in hard tissue following orthognathic surgery in patients showing mandibular prognathism with facial asymmetry and to clarify the rate of soft tissue change to hard tissue change using reconstructed 3D-CT images.
The subjects comprised four patients diagnosed as mandibular prognathism with facial asymmetry and treated byorthognathic two-jaw surgery. Pre- and posttreatment CT images were taken as data for precise diagnosis in all subjects. After reconstruction of 3D-CT images with the 3D reconstruction software Volume Extractor, four reconstructed 3D-CT images of both hard and soft tissues for pre- and post-treatment were exported to the 3D measurement software 3D-Rugle, and then those three-dimension coordinate systems were unified.
First, the thickness of preoperative soft tissue and theamount of changes in hard tissue and soft tissue following orthognathic surgery were measured by 3D-Rugle. Then, in order to clarify the rate of soft tissue change to hard tissue change, linear regression analysis was performed and the regression parameter (amount of soft tissue change/amount of hard tissue change) was examined.
Results were as follows:
The rate of soft tissue change to hard tissue change in retrusion points showed a higher value in mentum than in the buccal region, and a higher value on the deviation side than on the non-deviationside. On the other hand, the rate of soft tissue change to hard tissue change displayed a lower value in protrusion points than that in retrusion points both on the deviation side and non-deviation side in the buccal region.Moreover, the coefficient of determination for protrusion change exhibited a smaller value than that for retrusion change.These facts suggest that it is more difficult to predictprotrusion change than retrusion change.
Although the conventional cephalograms were unabled to precisely evaluate the difference between the right and left regions in patients with facial asymmetry, the three-dimensional analysis performed in this study was excellent in the detectability of difference between the right and left regions.Further, the present method enabled us to analyze widely and objectively the amount of soft tissue change to the amount of hard-tissue change following orthognathic surgery.Therefore, the rate of soft tissue change to hard tissue change obtained in this study is possibly useful in developing a system for predicting soft tissue change accompanied by orthognathic surgery.

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The treatment of a 16-year-old female with skeletal Class III using segmental maxillary distraction osteogenesis via an intraoral device and a mandibular bilateral sagittal split ramus osteotomy (BSSRO) is presented. The patient had maxillaryhypoplasia, mandibular overgrowth, anterior crossbite and remarkable crowding. Maxillary distraction osteogenesis using a custom-made intraoral device was carried out to simultaneously improve the disharmony between the upper dental arch and maxillary alveolar base as well as the retroposition of the maxillary bone. The surgical technique followed a minimally invasive osteotomy along the lateral maxillary walls and anterior segmental osteotomy using the Wassmund- Wunderer method, separating the maxillary bone into 3 segments. Following a latency period of 4 days, the frontal segmented was distracted anteriorly (8mm) while lateral segments were gradually distracted laterally (6mm) at a rate of 0.8mm/day. Distraction osteogenesis successfully improved the anterolateral maxillary deficiencies aswell as dental arch to alveolar base discrepancy. Orthodontic treatment for dental discrepancy was commenced without extraction of teeth.After 2 years, with completion of orthodontic treatment BSSRO was carried out. Due to prior correction of maxillary anterior discrepancy via distraction, minimal mandibular setback wasneeded. Three years following initiation of treatment, desirable and stable occlusion was achieved upon completion of postoperative orthodontics. Concavity of the middle face and mandibular prognathism were remarkably improved by such treatment.In conclusion, the utilized treatment modality provided several advantages, including restoring the lost harmony between upper dental arch and alveolar base, correcting both anterior and transverse discrepancies of maxilla, as well as conducting orthodontic treatment without dental extractions.

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