[in Japanese]

View full abstract

The purpose of this study was to investigate the postoperative self-images of former jaw deformity patients who had received corrective surgery. A self-portrait drawing test was given to twelve female patients who had undergone orthognathic surgery for prognathism 4-86 months previously. Surgeries consisted of either a Sagittal Split Ramus Osteotomy (SSRO) or Le Fort I osteotomy and SSRO simultaneously. Materials included 12 colored pencils, a pencil (HB), an eraser, and a sheet of A4 white paper (210×297mm). The subjects were instructed to draw (1) their own face (self-portrait) from any point of view as it looks now, (2) their current self-face from a lateral or frontal view, and (3) their preoperative self-face showing the most characteristic problem. Using the drawings the subjects were then questioned concerning their facial characteristics, satisfaction with surgical outcome, their most and least favorite facial characteristics and the most meaningful result of this treatment. The results were as follows: 1. The subjects correctly perceived the abnormal facial characteristics prior to surgery. 2. The subjects correctly recognized the postoperative morphological changes. 3. The subjects tended to be more assertive after surgical correction of their deformity. 4. The subjects emphasized the feminine characteristics in the postoperative self-portait drawings. 5. The orthognathic surgery seemed to have some relevance to feeling as charming. 6. All subjects perceived that corrective surgery had improved their facial appearance. The self-portrait drawing test appears to be a valuable tool in investigating the patients perception of their pre- and post-operative facial profiles. Further studies seem necessary to evaluate the clinical validity of self-portrait drawing test.

View full abstract

The purpose of the present cephalometric investigation was to establish a link in the series of morphological researches discriminating vertical patterns by the following means.
1. Developing an algorithm to discriminate vertical patterns of Class II malocclusions.
2. Clearly defining disparity of algorithms to discriminate vertical patterns between Class II and Class III.
3. Clinically applying the algorithm and examining its validity.
The subjects for this investigation were 117 female patients aged 15 years and over with the chief complaint of maxillary protrusion. The maxillary protrusions of 61 patients were accompanied by open bite, and those of 56 patients by deep bite. All the data were derived from initial lateral cephalometric radiographs.
The results of this investigation were as follows:
1. The value indicated by vertical indicator (VI) for Class II was y=-0.41(Lower facial height)+0.35(W its appraisal)+ 19.78.
2. The primary factor, when applied to vertical patterns, is less complicated in Class II than Class III.
3. Diagnosis of vertical patterns with VI for orthgnathic surgery was accomplished, the degree of treatment effect accompanying it was understood, and an index of stability for post treatment was obtained.

View full abstract

Speech disorders in patients with severe skeletal class III malocclusion are predominantly distortion, and distortion on the fricatives occurs most frequently. However, the acoustic characteristics of these distorted fricatives and the mechanisms of speech production have not been clarified.
The fricative /s/ pronounced by the skeletal class ET patients before and after orthognathic surgery were acoustically analyzed, and the acoustic characteristics of the distorted fricative /s/ and the cause of distortion were reported.
In this article, the fricative /∫/, which was pronounced by the orthognathic surgical patients, was acoustically analyzed to investigate the acoustic characteristics of the distorted /∫/ and the cause of distortion, and the relationship between the acoustic characteristics and the hearing impression was determined. The fricative /∫/ is the same as fricative /s/ in the manner of articulation but differs in the place of articulation.
The results of this study were as follows:
1) The sound pressure level of the middle frequency range, which was around 5kHz on the presurgical spectrum of the patients, was found to be lower than that of normal subjects, but the level of this range on the postsurgical spectrum rose. 2) The pressure level of the middle frequency range of the fricative /∫/ was influenced by the resonance of the vocal tract. 3) The naturality of the fricative /∫/ also improved after surgery in the results of the hearing test. Therefore, the distortion of /∫/ was caused by the deformity of the vocal tract of severe skeletal class III malocclusion.

View full abstract

Methods of evaluating the need for orthognathic surgery during orthodontic treatment was investigated by comparing two similar cases of skeletal class III malocclusion.
Cephalometric analysis of the maxillary and mandibular skeletal positions is essential in determining the need for surgical orthodontic treatment. However, surgery in some borderline cases is optional.
Cephalometric analysis indicated that case 1 should be treated by orthognathic surgery, while case 2 should be corrected by orthodontic treatment only. The effect of surgical and non surgical treatment on ANB, APDI, AB-MP, Wylie's assessment, and AO-BO was evaluated.
The following results were obtained:
1. Several analyses should be done in determinig the need for orthognathic surgery in the treatment of skeletal class III malocclusion.
2. Skeletal correction requires evaluation of the antero-posterior skeletal discrepancy and vertical discrepancy.
3. Dental correction requires evaluation of the inclination of the occlusal plane and relationship of the first molars.
4. Esthetic correction requires analysis of esthetics.

View full abstract

A few case reports on the mandibular surgical lengthening therapy by McCarthy et al., Takato et al. and Kawakami et al. have been published in recent journals.
In this study, three females (4 years and 8 months, 6 years and 2 months, and 12 years and 10 months), who underwent mandibular surgical lengthening, were analyzed with regard to their facial changes by means of photometry and cephalometry.
The results were as follows:
1) Mandibular surgical lengthening was effective on the patient with micromandible such as hemifacial microsomia within a short period.
2) The effects of this therapy were more prominent on the change of soft tissue than that of hard tissue.
3) After removing the lengthening appliance, a fair amount of relapse was noticed.

View full abstract

A clinical statistical study was carried out on surgical correction of jaw deformation in patients who visited Osaka Dental University.
1) The annual number of the new patients with jaw deformation slightly increased. A marked increase was observed after 1990.
2) The male/female ratio in the new patients was about 1: 2.
3) The mean age at the time of initial consultation was 20.4 years for males and 20.3 years for females.
4) According to age groups, the number of patients aged 16-20 years accounted for 47.6% and that of patients aged 21-25 years for 30% of all patients.
5) Concerning area distribution in the new patients, Osaka prefecture accounted for the highest percentage (71%), followed in order by Hyogo, Nara, and Oyoto prefectures.
6) According to the type of jaw deformation, skeletal mandibular protrusion accounted for the highest percentage (84%).

View full abstract

The number of the patients with skeletal Class III malocclusion, requiring surgical orthodontic treatment, has increased, patients' complaints range over minute details, and patients expect remarkable aesthetic prognoses.
A number of patients with skeletal Class III malocclusion have upper incisors which are inclined labially and lower incisors which are inclined lingually before treatment. Following surgical orthodontic treatment, axial inclination of upper incisors greatly affects patients' labial forms and that of lower incisors and migration range of mandibles often affect patients' mentum forms. Consequently, in presurgical orthodontic treatment, axes of incisors must be greatly corrected. Nevertheless, in some cases, mandibular migration is so slight that little aesthetic alteration results. In these cases, some patients complain of unaesthetic mouths, therefore the patients' aesthetic appearance after orthodontic treatment must be taken into consideration before the treatment.
In this report, a patient with skeletal Class III malocclusion with labially inclined upper incisors and protruding upper lip was presented. This patient had upper premolars extracted in presurgical orthodontic treatment so that she obtained morphologically good prognosis. Furthermore, the effects on the appearance of mouth were discussed when upper premolars were extracted in surgical orthodontic treatment.

View full abstract

The sagittal splitting ramus osteotomy of the mandible is widely used for the correction of various dentofacial deformities in Japan. The rigid fixation of the split bone segments seems to be main means to redure the duration of maxillo-mandibular fixation and postoperative relapse of the mandibular position. However, the skin incision for fastening the screws has some disadvantages, for example, scars, the injury of the facial artery or the injury of the facial nerve.
We developed a modified technique to fix the segments bicortically with titanium screws using the contra-angular handpiece for dental implant installation. This is an intraoral fixation method without skin incision. Moreover, very slow and high torque screwing let the segments contact closely and be stable. Operations can be performed by this method without any complications and having good post operative stability.

View full abstract

Genioplasty is a routine procedure for the improvement of profile in the correction of dentofacial deformities. Horizontal osteotomy of the inferior border of the mandible is usually performed. Osteotomized genial segment has conventionally been fixed with wire osteosyntheses. However, since this method had many disadvantages, use of rigid internal fixation with mini bone plates and screws or screws alone in genioplasty has spread. Rigid internal fixation provides a rapid and rigid means of stabilizing the inferior mandibular fragment after horizontal osteotomy, and is able to achieve the optimum bony union and the small resorption of bone. Moreover, screw fixation seems to have advantages over mini bone plates and screws, and also lag screw fixation seems to have advantages over position screw fixation.
In 1989, we began using lag screw fixation after horizontal osteotomy in genioplasty by the use of only one titanium mini non self-tapping screw in the median part of the chin, and this screw is inserted through inferior approach and fixed to the lingual cortex of the mandible.
So far, we have used it in 50 cases.
This method has the following advantages:
1. Excellent rigid osteosynthesis.
2. Easy and rapid procedure.
3. Easy removal.

View full abstract

In our hospital, “Safety” is the most important in perioperative management. Perioperative management of simultaneous bimaxillary orthognathic surgery is comparatively difficult due to complications concerning the area in which it is performed.
Our perioperative managements are summerized as follows: 1. Nasotracheal intubation is continued to the day after surgery to avoid upper respiratory obstruction due to edema and bleeding.
2. Stored and hemodilutional autotransfusion and hypotensive anesthesia are performed to avoid homologous transfusion and postoperative anemia.
3. CVP catheter is used for postoperative iv medication.
4. Linear polarized near-infrared light irradiated to reduce facial edema and to improve sensory paralysis of lower lip.
The most important factor is close cooperation between anesthesiologist and OMF surgeon to offersafety to the patient, undergoing perioperative management of simultaneous bimaxillary orthognatic surgery.

View full abstract

To estimate whether the stored autologous blood volume of 600ml for simultaneous bimaxillary orthognathic surgery is reasonable or not, 23 patients who underwent this surgery from October 1993 to January 1995 were studied, and the following results were obtained.
1. Compared with prephlebotomical data, hemoglobin and hematocrit values of the preoperative stage did not decrease significantly and reticulocyte did not increase significantly.
2. Compared with prephlebotomical data, total protein decreased significantly during the preoperative stage, but was restored one month after surgery.
3. Mean blood loss of simultaneous bimaxillary orthognathic surgery in our hospital was about 700 ml.
4. W e were able to avoid homologous blood transfusion, even in the patient who lost 1, 778ml of blood.
5. No abnormal laboratory data was noted one month after surgery.

View full abstract

We report a case of acromegaly using sagittal splitting osteotomy of the mandibular ramus for progenia, partial tongue excision for macroglossia and osteointegrated implants for missing teeth resulting from occlusal failure after a traffic accident.
A 28-year-old male had progenia and macroglossia after treatment for elevated serum growth hormone levels. In the operation we performed, the mandible was moved back 18mm, 18cm³ of the tongue was removed by excision. Intraoral examination revealed the over jet had improved from -13mm to 4mm and the over bite from 6mm to 3mm. The ANB difference went from -12.5° to-3.5°. However the tongue maintained contacted with the corner of the mouth at rest, but contractility was good. Osteointegrated implants were used to improve the occlusal condition, resulting recovery of mastication function. At 23 months postsurgery, the patient shows stable results, significantly improved occlusion, and a stable growth hormone level.

View full abstract

Questionnaires were sent to oral and maxillofacial surgery, orthodontics, anesthesiology departments where board members of the Japanese Association of Oral and Maxillofacial Surgeons, Japan Orthodontic Society, or Japanese Dental Society of Anesthesiology are working. Questionnaires included questions on surgical procedures applied to mandibular deformities, fixation methods between segments, the duration of postoperative intermaxillary fixation, complications of perioperative phase and preoperative and postoperative orthodontic treatments.
This paper, as part 2 of this study, presents the results of the survey on positioning procedures of the proximal segment of the mandible after osteotomy and preoperative and postoperative orthodontic treatment based on the replies from 22 orthodontic departments and 99 oral and maxillofacial surgery departments.
Results
1. Two thirds of oral and maxillofacial surgery departments position the proximal segment before bone fixation, if sagittal splitting ramus osteotomy was applied in the treatment of mandibular deformity.
2. Many kinds of procedures for positioning the proximal segment of the mandible, i. e., from manual positioning to positioning with special devices, are applied.
3. Rigid fixation (screws, and miniplate and screws) group uses some positioning procedures of the proximal segment more frequently than the nonrigid fixation (wire and circumferential wiring) group (p<0.01).
When compared between oral and maxillofacial departments that uses screws, and miniplate and screws, departments using screws tend to position the proximal segment more frequently than those using miniplate and screws (p<0.01).
4. Most oral and maxillofacial surgery departments (94/97) answered that orthodontic treatment is applied preoperatively and/or postoperatively in the treatment of mandibular deformity. Comparison whether all orthognathic patients receive orthodontic treatment preoperatively or not, between hospital with and without orthodontic department, revealed that patients treated at hospitals having orthodontic department have a greater chance to receive preoperative orthodontic treatment than patients treated at hospital without it (p<0.01).
5. One third of the orthodontic departments have cases who were referred for postoperative orthodontic treatment without any preoperative consultations

View full abstract

The purpose of this study was to investigate the changes of condylar movements after orthognathic surgery of mandibular prognathism using sagittal splitting ramus osteotomy (SSRO). Condylar path tracings were recorded for maximum opening, protrusion-retrusion, medial excursion and habitual masticatory movement of the mandible by means of a computer aided diagnostic axiograph.
The following results were obtained.
Case 1: A mandibular prognathism due to overgrowth of mandible was diagnosed in a 33-year-old female. After combined surgical-orthodontic treatment, each condylar path tracing coincided. In habitual masticatory movement, the rhythm of condylar movement became stable and the velocity of condylar movement increased. The difference of condylar position between RCP and ICP disappeared.
Case 2: A mandibular prognathism was diagnosed in a 19-year-old-female. After orthognathic surgery, the distance of condylar path tracing in protrusion and medial excursion movements increased and the asymmetry of condylar movement was corrected in each condylar path tracing. The rate of condylar movement in habitual masticatory movement increased.
These two cases indicated that surgical orthodontic treatment for skeletal Class III case by means of a SSRO has favorable effects on the function of the condylar movements.

View full abstract