The purpose of this study was to examine molar occlusal changes in the frontal dimension and their effects on the anterior overjet and overbite following surgical orthodontic treatment.
The subjects were 14 adult patients with mandibular protrusion treated with sagittal splitting ramus osteotomy. Serial sets of gnathostatic models and lateral cephalograms were used for analysis. Materials were taken at the stages of first examination, end of active treatment, and in retention (more than two years after the end of active treatment).
Buccolingual inclination of the upper and lower first molar, lateral overjet and overbite, and inter molar distance in both arches were measured on the three-dimensional graphics of the dental model produced by the noncontact three-dimensional measuring unit. The anterior overjet and overbite were also measured on the lateral cephalometric radiographs. Changes of molar inclination, inter molar distance and molar occlusion during the treatment period and the retention period were analyzed, and a correlation between changes of molar occlusion and those of anterior overjet and overbite in the retention period was examined.
The results were as follows:
1. There was a significant correlation between the changes of molar inclination during the treatment period and those in the retention period (upper lst molar; r=-0.71, p<0.01, lower lst molar; r=-0.58, p<0.05). These results suggested a relapse tendency of molar inclination in the retention period. However, no significant correlation was found in the changes of upper and lower inter molar distance between treatment period and retention period, and lateral overjet and overbite on both sides remained stable in most of the cases in the retention period. It was suggested that the molar occlusion in the retention period was characterized by the relapse tendency of the molar inclination without the changes of the inter molar distance.
2. In the retention period, the changes of the anterior overbite had significant correlations with the lateral overjet (r=0.65, p<0.05) and the lateral overbite (r=0.64, p<0.05).
It was concluded that the change of the molar occlusion played an important role for long-term stability of the occlusion after surgical orthodontic treatment.

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A clinico-statistical observation was carried out on 305 patients (314 cases) who underwent orthognathic surgery between 1981 and 1994 at Second Department of Oral and Maxillofacial Surgery, Showa University Dental Hospital.
The results were as follows:
1. The number of patients with jaw deformity has increased in recent years. The average number of patients per year was 22, about 12.4% of the total number of inpatients.
2. The age of patients ranged from 15 to 40 years with a mean of 22.3 years.
3. The patients were 85 males and 220 females, and the male-female ratio was 1: 2.6.
4. The most frequent chief complaint was malocclusion.
5. Of these patients, 272 cases (89.2%) had mandibular prognathism with or without another jaw deformity.
6. Sagittal splitting ramus osteotomy (SSRO) was performed on 266 cases (84.8%).
7. The average operation time and blood loss in SSRO were 4hr. 25min.±1hr. 2min. and 471.7ml±339.1ml, respectively.
8. Osteosynthesis of bone fragments in SSRO was carried out as follows: 36 cases with circumferential wiring, 16 cases with sapphire lag screw, 161 cases with two-dimensional positioning screw, 13 cases with three-dimensional positioning screw, and 40 cases with mini-plate fixation.

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Data from questionnaires consisting of 36 items which were sent to patients with prognathism were analysed, for self-evaluation on the postoperative release from various troubles that were suffered before surgery.
The subjects were 77 patients (14 males and 63 females) out of 147 patients who had undergone sagittal splitting ramus osteotomy in our clinic from 1989 to 1994. The patients were divided into three groups with different facial profile, skeleton, and occlusion: prognathism group (28 patients with mandibular prognathism only), asymmetry group (27 patients with mandibular prognathism with asymmetry), and open bite group (22 patients with mandibular prognathism and open bite).
The results were as follows:
1) As for the preoperative particular troubles, those concerning occlusion and facial profile were noted in the prognathism group and those concerning mastication in the open bite group. The patients in the asymmetry group had the same troubles as noted in the above two groups, but suffered from multiple troubles, including temporomandibular joint disorder and others. Moreover, they were comparatively younger.
2) In the open bite group, only a few patients evaluated the postoperative change in the facial profile, but much more patients evaluated the change in speech after surgery.
3) Over 90 per cent of the evaluated patients from the three groups the improvement of occlusion after the operation, but it took more time for patients to eat an ordinary meal satisfacorily in the asymmetry group.
4) Preoperative discomforts due to the temporomandibular joint syndrome were most remarkable in the asymmetry group, but less reduced in the prognathism group after surgery.
5) As for the change in tongue and the numbness of lip or chin after surgery, there were no significant differences among the three groups.
6) The difference between before and after surgery in the open bite group was move noticeable than the others.
7) As for the motive of undergoing surgery, although many patients were recommended to undergo surgery by dentists among the three groups, more patients from the prognathism group decided to undergo it by themselves.
8) As for the overall evaluation for the result of surgery, most patients in the three groups showed positive response to surgery. As the main reason, aesthetic improvement was evaluated in the prognathism group, that of occlusion and mastication in the open bite group, and that of the psychological aspect in the asymmetory group.

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In order to build a criterion of facial morphology diagnosis, the authors previously proposed the facial form classification chart. This chart was clinically used to diagnose 176 cases of maxillofacial deformity in five institutions, and these were subjected to a statistical study. The results were as follows:
1) Facial morphology diagnoses given to 176 cases aggregated 283. The most common diagnosis was mandibular prognathism (123/176, 70%), followed by facial asymmetry (66/176, 38.0%), and maxillary retrognathism (38/176, 21.6%).
2) Ninety cases (90/176, 51.1%) were given a single diagnosis and 86 (86/176, 48.9%) were given multiple diagnoses. Mandibular prognathism only was most common (56/176, 31.8%), followed by mandibular prognathism with maxillary retrognathism (33/176, 18.8%), mandibular prognathism with facial asymmetry (29/176, 16.5%), facial asymmetry single (19/176, 10.8%) and so on.
3) The facial form classification chart was empirically assumed to systematize a common proress of facial morphology diagnosis, and offers a guide line that could standardize diagnosis of maxillofacial deformities.

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A case of acromegaly accompanied by pituitary adenoma in a 39-year-old woman was reported. Her manifest conditions in the field of oral surgery were jaw asymmetry, mandibular protrusion, hypertrophy in the right condyle, and macroglossia. Prior to oral surgical reduction, pituitary tumor was resected by the transsphenoid approach at the Department of Neurosurgery and growth hormone was controled almost at the normal level thereafter. Surgical reduction was performed by right condylectomy, partial glossectomy, and bilateral sagittal split ramus osteotomy for mandibular set back. After surgery, the oral conditions improved, without disturbances in chewing, mandibular opening or closing, and esthetic appearance. However, further follow up is needed in cases like the present one.

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The degree of postoperative relapse associated with micrognathia appears much greater than that observed after operation for mandibular prognathism. The inverted-L osteotomy with bone grafting was considered as an alternative method for true lengthening of the mandible and has been advocated to improve postoperative stability compared with other surgical techniques.
The patient was a 18-year 6-month-old female who had mandibular asymmetry and masticatory dysfunction. Computed tomography and panoramic radiograph showed severe deformity of the left ramus and condyle causing micrognathia. After preoperative orthodontic treatment, surgery was performed, including a Le Fort I osteotomy to improve asymmetry of occlusal plane, and advancement of the mandible was accomplished by mandibular sagittal split osteotomy on the right side and the inverted-L osteotomy with interpositioning of a bony autograft on the left side. Furthermore, after a year, onlay graft of the mandible was performed to obtain facial symmetry. The resultant Class I occlusion was apparently stable for a long time. Masticatory function had greatly improved as well as facial esthetics.

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The purpose of this study was to evaluate the clinical efficacy and changes of magnetic resonance (MR) imaging of temporomandibular joint (TMJ) by intraoral vertical ramus osteotomoy (IVRO). The subjects were ten patients with mandibular prognathism associated with TMJ clicking and dysfunction.
Ten patients were treated with IVRO and followed-up for 226 days on average. Signs and symptoms and MR imaging of TMJ were evaluated in pre- and postoperative phases. Prior to IVRO, all patients had been treated nonsurgically for their TMJ dysfunction, and most of the patients relieved pain, but not joint clicking. Preoperative orthodontic treatment was performed for about 13 months.
Surgical correction of mandibular prognathism by IVRO was successfully done without any episode of relapse, and clicking sound disappeared in all patients after surgery. There was neither associated pain nor dysfunction in all TMJs. In the MR imagings, postoperative improvement of preoperative abnormal disc configuration was found in four of eight TMJs, nine joints disclosed appropriate condylar sag, and normal disc-condyle coordination was restored in seven of ten joints. Interestingly, despite of no obvious imaging changes in the remaining subjects, clinical improvement was confirmed.
These results suggested that IVRO may be a suitable surgery for a jaw deformity patient with concomitant TMJ clicking and dysfucntion.

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Seventeen cases (28 sites) that underwent alveolar segmental osteotomy were evaluated on the vitality of tooth pulp of the osteotomy site with electrical pulp stimuli and the condition of the periodontal tissues adjacent to cutting lines of alveolar bone after surgery.
The operated sites were distributed in 9 anterior and 3 posterior teeth of the maxilla and in 11 anterior and 5 posterior teeth of the mandible.
The results were as follows: The recovery rates of pulp vitality were gradually increased until 2 years postoperatively.
Finally, their rates were 59.1% in the portions adjacent to the operated site and 96.8% in the other portions.
Among the four sites, those of the posterior portions of the maxilla showed the highest recovery rate and those of the posterior portion of mandible demonstrated the lowest.
There was no clear differentiation of the recovery rate between the bone segment with 6 teeth and the bone segment with 4 teeth.
Even unrecovered teeth, however, demonstrated no color change in almost all cases. Furthermore, a few cases demonstrated periodontal pocket formation, gingival recession, and/or absorption of alveolar bone.
In conclusion, without direct injury to the teeth during operation, pulp sensibility seems to be recovered naturally. Therefore, the distance between the apices of the teeth and the cutting line of osteotomy is a very important factor for protecting tooth vitality.

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