The goal of this study was to develop objective functional method of evaluating treatment systems for patients with jawdeformations, a treatment which is expected to increase in the future. We attempted to discern the characteristics of the recovery process ofpostoperative jaw motility and muscle function by studying preoperative and postoperative skeletal class III patients and comparing themwith normal controls, placing emphasis on factors outside the treatment period of the jaw deformation patients.
Using skeletal class III patients as controls, we measured jaw movements and muscle function over a period extending beyond that of thesurgical orthodontic treatment, which includes the periods prior to initiation of the preoperative orthodontic treatment and aftercompletion of the retention.The following results were obtained;
1) Orthognathic surgery not only corrected the form of the malocclusion, but is also improved the function of the masticatory system.
2) A new masticatory form was essentially established by the maxillomandibular relationship created by the orthognasthic surgery.
3) Masticatory function in the patients was an improvement over that before the operation, and was either as good as the function in personswith normal occlusion or better.
4) Maintenance of the occlusion during the postoperative recall seemed an important factor in the process of recovery of masticatoryfunction.

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The author devised a method of measuring soft tissue in order to determine the patient's soft tissue profile (STP) in cases of mandibular prognathism.The purpose was to find a procedure for applying preoperative orthodontic treatment and a means of determining the mode of operation. Charts of STP standard deviation among normally occluded male and female patients were made. The relations among Groups A, B, C, D and E were investigated by measuring soft tissue according to Sanborn's classification modified by Tsuji, et al.
From these studies we concluded that both the hard and soft tissues of each group were closely related. This information guided us as to the manner in which the surgical procedure would be approached.
Each of the above 5 groups were eventually classified into 3 types prior to preoperative orthodontic treatment.
Type1
Group A and E are characterized by forward protrusion of the chin and the upper and lower lips.
They require labial tipping of the incisors of the mandibule, and occasionally lingual movement of the maxillary incisors in preoperative orthodontic treatment.
Type 2
Group D is typically characterized by severe mandibular prognathism, and requires labial tipping movement of the upper and lower incisors in preoperative orthodontic treatment. In cases where the operation is done only on the mandibule, consideration of tooth axis inprovement is required so that the width of posterior displacement dose not exceed 15.0mm.
Type 3
Group B and C are characterized by slight forward mandibular protrusion. The profile has pseudomandibular prognathism because of retrogression of the upper lip, and lower facial height. In preoperative orthodontic treatment, the overbite is shortened in order to decrease lower facial height. Postoperatively, the chin should be posteriorly receded and rotated upward. Furthermore, displacement shonld be minimized.

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Fifteen cases of patients with dentofacial deformities who underwent a Le Fort Iosteotomy were compared with nasal cavity findings and nasal airway conductance before and after the operation.The following results were obtained.
1) Before the operation, abnomal forms (deflected nasal septum and mucosal hypertrophy) were recognized in 12 patients.9 of 12 cases had lower than normal nasal airway conductance.
2) Nasal airway conductance was increased in 8 patients.These cases had abnormal forms in bilateral or unilateral nasal cavity before the operation.
3) Nasal airway conductance was decreased in 5 patients, which had bilateral normal form and nasal airway conductance was in normal range before the operation.
4) Most of patients with nasal septum perforation had been recognized as either crista or spina before the operation.

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