This study investigated the reproduction of a human model using data acquired by means of three-dimensional facialmeasurement with an optical surface scanner and examined the tolerance in clinical use. Furthermore, three-dimensional analysis of pre- and postoperative midfacial soft tissue change, especially the morphology of external nose regions, was carried out on patients who had undergone bimaxillary orthognathic surgery. Six adults (two males and four females age 25 to 33 years) were recruited to investigate the reproduction of the human model. To compare pre-and postoperative midfacial soft tissue change, 17 patients (two males and 15 females age 16 to 24 years) were examined prior to and 6 months after bimaxillary orthognathic surgery. Surgical procedures performed were Le Fort I osteotomy and bilateral sagittal split osteotomy in all patients. The reproduction of the model in this study ranged from 0.23 to 1.26 mm. The results showed that there was a small error in areas of the forehead and orbita, whereas there was a large error in the lower face. With respect to the postoperative shape of the external nose region, the correlation between the displacement of hard and soft tissue was detected at the landmark of subnasal (R=0.73), and several landmarks measured surrounding the external nose moved more forward than subnasal. In addition, the postoperative width of alar increased (3.5±1.7mm). In cases of maxilla moving forward by more than 3.0mm, the displacement of pronasal that tended to move upward had an influence on postoperative facial change. In conclusion, as far as the shape of the external nose is concerned, the distance between the landmark of pronasal and alar base was reduced and the amplitude of alar showed an increase postoperatively, resulting in a wider nose. Morphological change of the external nose plays a great role in overall facial alteration after surgery.

抄録全体を表示

This study evaluated the relationship between maxillofacial morphology, volume of masseter muscle and inclination of masseter muscle in mandibular prognathism patients with those having normal occlusion.
The subjects consisted of 10 mandibular prognathism patients (mean: 21.6 years old) and 25 male (mean: 27.5 years old) with normal occlusion. The maxillofacial morphology was observed by lateral cephalograms. The volume and inclination of masseter muscle were determined from MRI images.
There was no significant difference in volume of masseter muscle between mandibular prognathism patients and those with normal occlusion. In mandibular prognathism patients, the volume of masseter muscle was not correlated with any items, but the inclination of masseter muscle was correlated with SNB, ANB, FH-palatal plane, Gonial angle, Ramus inclination, Y axis, and Saddle angle. In patients with normal occlusion, the inclination of masseter muscle was correlated with Ramus inclination, and the volume of masseter muscle was correlated with FMA, MP-palatal plane, SN-GoGn, Gonial angle, and Saddle angle. These results suggest that the inclination of masseter muscle is correlated with mecisodistal development.

抄録全体を表示

The Le Fort I osteotomy is a common surgical procedure for the treatment of dentofacial deformities. Because this procedure includes osteotomy of the medial and lateral maxillary sinus wall, pterygomaxillary dysjunction and down-fracturing of the maxilla, it has significant risk of severe hemorrhaging from the descending palatine artery lying in the greater palatine canal.
We investigated the position of the greater palatine canal to provide a clinical safety guideline that minimizes injury to the descending palatine artery during Le Fort I osteotomy in Japanese patients.
Seventy-two Japanese patients with dentofacial deformities, 33 males and 39 females ranging from 16 to 42 years old (mean age 25.5 years old) were examined with computed tomography (CT) scans. The axial images 3 mm above the nasal floor were used for this analysis.
Anatomical position of the greater palatine canal was localized by three measurements, anterior, posterior and lateral distance. The anterior distance was defined by the distance from the piriform rim to the greater palatine canal and the posterior distance from the pterygomaxillary fissure to the greater palatine canal. The lateral distance was defined as the distance from the lateral margin of the pterygomaxillary fissure to the lateral sinus wall.
The average of the anterior distance was 36.67mm (range 32.69 to 42.66mm). There was a significant difference in the anterior distance between sexes. Based on the minimum anterior distance in this study, the safety guideline for Japanese patients for osteotomy of the medial sinus wall was assumed to be 30mm in Le Fort I osteotomy.
The average of the posterior distance was 1.89mm (range 0 to 4.69mm). There was a negative significant correlation between age and posterior distance (γ=-0.23). Fifteen patients showed a distance of less than 1mm. It was assumed that these patients had a higher risk of injury to the descending palatine artery due to the narrow space between an osteotome and the greater palatine canal.
The average of the lateral distance was 8.09mm (range 3.75 to 13.59mm). Fourteen patients showed a lateral distance of more than 10mm. The lateral distance is considered to be the length of bony contact between the posterior maxilla and the pterygoid plate that should be separated by an osteotome. The long bony contact increases the difficulty in pterygomaxillary dysjunction and the risk of untoward fracture leading to injury of the artery.

抄録全体を表示

We evaluated clinicostatistically the status of orthognathic surgery in our department between 1990 and 2001.
The results were as follows:
1. Orthognathic surgery was performed on 189 patients, and the annual number of operations has markedly increased since 1994.
2. The patients consisted of 135 females and 54 males, whose ages in mode were 16 and 17 years old, respectively.
3. The chief complaints in 90% of all patients were malocclusion and esthetic disturbance.
4. Approximately 90% of. all patients were diagnosed as mandibular protrusion without or with mandibular asymmetry, open bite, or maxillary retrusion.
5. Bilateral sagittal split ramus osteotomy (SSRO) was performed on 96.8% of all patients.
6. The recorded median of surgical duration and surgical blood loss were 155min. and 255g for SSRO, 260min. and 690g for SSRO with genioplasty, and 290 min. and 877g for two-jaw surgery.
7. Osteosynthesis of bone fragments in SSRO was carried out as follows: 173 cases with miniplate fixation, 6 cases with circumferential wiring, and 8 cases with screw fixation.
8. The duration of intermaxillary fixation in SSRO was 15 days after 1996.

抄録全体を表示

Surgical duration and hemorrhaging have traditionally been used as indicators of surgical stress. However, recent advances in molecular biology have clarified the roles of various cytokines, and several studies have documented the usefulness of serum cytokine measurement in assessing surgical stress. In the present study, we ascertained the levels of surgical stress by measuring the levels of serum cytokines in patients who underwent bilateral sagittal split ramus osteotomy (BSRO) and those who underwent BSRO and Le Fort I osteotomy (two-jaw surgery: maxillomandibular traction). We also investigated whether serum cytokines could act as useful indicators for surgical stress associated with orthognathic surgery by direct comparison with surgical duration and hemorrhaging.
The subjects were seven patients who underwent BSRO (Group 1) and six patients who underwent two-jaw surgery (Group 2) between June 2001 and March 2002. In these patients, serum CRP, surgical duration, and intraoperative hemorrhaging were measured and compared with serum cytokine levels (TNF-α, IL-1β, IL-6, IL-8, IL-10, and IL-12) measured before surgery, immediately after surgery, and at 1, 3 and 7 days after surgery.
Surgical duration and hemorrhaging in Group 2 were significantly higher than those in Group 1 (p<0.05). With regard to serum cytokines, levels of IL-6 and IL-10 immediately after surgery for Group 2 were significantly higher than those for Group 1 (p<0.05), but no marked differences were seen at any other measurement points. Levels of IL-1β and IL-12 were often below the detection limits, and as a result, no clear correlation could be found between the two groups. Furthermore, levels of serum IL-6 immediately after surgery showed a strong positive correlation to surgical duration and hemorrhaging (p<0.01).
The results of the present study suggest that the levels of serum IL-6 immediately after surgery may be a useful indicator of surgical stress associated with orthognathic surgery, . because levels of serum IL-6 were high immediately after two-jaw surgery.

抄録全体を表示

Reliability of superior repositioning and postoperative stability of the maxilla in 11 non-cleft patients who underwent combination (Le Fort I and horseshoe) osteotomy for superior repositioning of the maxilla were investigated. In all patients, the maxilla was first osteotomized and fixed with four titanium miniplates. A bilateral sagittal split ramus osteotomy of the mandible (BSSRO) was then carried out and titanium screw fixation was performed. No maxillomandibular fixation with stainless steel wire was used postoperatively in any patient. Lateral cephalograms were obtained preoperatively, 2 weeks postoperatively, and 3, 6, and 12 months after surgery. The changes in the anterior nasal spine (ANS), point A (A), and point of maxillary tuberosity (PMT) were examined on the cephalograms. The discrepancy between the planned and measured superior repositioning of the PMT ranged from only 0.5 to 1mm (mean: 0.73mm). Therefore, the maxillae in the 11 subjects were repositioned nearly in their planned positions during surgery. In addition, no significant postoperative changes in the examined points of the maxilla were found. These results suggest that a combination of Le Fort I and horseshoe osteotomy is a useful technique for reliable superior repositioning of the maxilla, especially in its posterior portion. Moreover, the postoperative stability of the maxilla treated using this combination osteotomy is comparatively satisfactory.

抄録全体を表示

A 16-year-old female patient underwent mandibular lengthening by Backward Distraction Osteogenesis (BDO) for Angle Class II case with retrognathia. We experimented with facial and skeletal changes using cephalometry, and also analyzed the patient for possible changes of oral functions before and after treatment.
The results were as follows:
1) The mandibular lengthening showed effective results within five days, and the patient's profile and jaw relationship both improved after the treatment.
2) Relapse was not seen and the posttreatment conditions were stable after removing the lengthening device.
3) As for oral functions, maximum vertical opening increased and lateral movement resulted in a symme-try after BDO in the path of mandibular border movement. At the maximum velocity of opening and closing phases, a click point that had appeared clearly during the closing phase before the treatment, had disappeared after the treatment.
4) As for MRI findings, both discs were displaced anteriorly without reduction before the treatment, but the anterior displacement with reduction was observed after the treatment during the opening phase.
From these results, it was suggested that the BDO which was combined with SSRO and mandibular lengthening seemed to be a favorable technique to advance the mandible of an Angle Class II case with retrognathia.

抄録全体を表示

It is difficult to predict the necessity of transfusion during orthognathic surgery. In order to examine the propriety of orthognathic surgery without preparing for transfusion, we examined 62 patients who underwent orthognathic surgery in our hospital during 3 years from January 2000 to December 2002, and performed statistical analysis of the blood loss and pre- and postoperative values of blood examination for each surgical procedure.
The results were as follows:
1. It seemed that a greater amount of blood is lost in double-jaw surgeries compared to single-jaw surgeries. There was a significant difference between the sagittal split ramus osteotomy combined with Le Fort I osteotomy group and the intraoral vertical ramus osteotomy group (P< 0.05). However, no case was indicated for transfusion intraoperatively.
2. The larger the amount of blood lost in each surgery, the greater the decrease in values of blood examination (red blood cells, hemoglobin, hematocrit) at 1-week post-operation. A significant difference was found between pre-operation and 1-week post-operation except in the intraoral vertical ramus osteotomy group (P<0.05). Although the values tended to decrease slightly until 2-weeks post-operation, no general complication occurred.
These results indicate that there is little risk of remarkable bleeding in routine orthognathic surgery. Therefore, it seems appropriate to carry out the operation without preparing for transfusion.

抄録全体を表示

Unilateral scissors bite is a rare malocclusion that results in functional problems. Orthognathic surgery is a possible solution for the patient in order to reduce the discomfort during the upright period of the posterior segment.
The subject was a 12-year and 1-month-old male who expressed the chief complaint of dysmasesis caused by a scissors bite on the right side. The medical history revealed an autistic tendency and communication handicap. Overerupted upper-right premolars and molars, and linguo-inclined lower-right premolars and molars were indicated in the initial records. Orthognathic surgery was performed after the patient had mentally matured, which took about 3 years. Prior to the operation, all third molars were extracted under general anesthesia. The following surgical correction on the right side was first carried out: 1. Upper-right posterior segmental osteotomy, 2. Sagittal splitting ramus osteotomy (right side), and 3. Mandibular body step osteotomy (right side). A good interdigitation in the posterior segment on the right side was established by the following multibracket appliance in order to reduce the risk of post-operative change.
After 2 years and 3 months of active treatment involving orthognathic surgery, retention was started. The treatment aims have been achieved, both in terms of addressing the patient's concerns and in establishing a fairly good functional occlusion.

抄録全体を表示

Progressive condylar resorption (PCR) has been identified as a major problems in the outcome of orthognathic surgery. In order to prevent postoperative PCR, a patient with severe retromandible underwent mandibular lengthening using distraction osteogenesis with intraoral devices. An occlusal splint was simultaneously used during the distraction and consolidation period for the management.
The patient was a 27-year-old female. Mandibular body osteotomy was performed in the angle region. The vector of distraction was parallel to the occlusal plane. The latency period was 7 days. The distraction rate was 0.8mm/day (0.4mm twice daily) for 18 days and the mandible was lengthened approximately 14mm in total. After 30 days of stabilization, the intraoral devices were removed. Enough osteogenesis was confirmed, and Le fort I type osteotomy and genioplasty were performed. Post-operative PCR has not manifested so far. Clinical and radiographic examination revealed no marked changes in the occlusion and profile at 14 months after distraction.

抄録全体を表示

Cases of scissors bite caused by functional mandibular shift are considered difficult to treat, because of the potential shift to skeletal deformities. We treated a 12-year-old boy using two plates to reconstruct the occlusal plane. Functional side shift with deep bite improved during the growing period as the vertical dimension was controlled by the plates. It is suggested that skeletal deformities could be avoided by early correction of mandibular deviation, although not all cases are indicated for the treatment.

抄録全体を表示

This paper presents the case of a 31-year-old female with severe maxillary protrusion who received surgical orthognathic treatment by distraction osteogenesis. Severe transverse maxillo-mandibular discrepancy with significant crowding, and labial tipping of the maxillary incisors further compounded this problem. A two-stage surgical procedure was performed. The first-stage operation involved Le Fort I osteotomy and median palate osteotomy in the maxilla and median osteotomy in the mandible. The maxilla was widened by 9mm, the mandible by 6mm. Bilateral maxillary first pre-molars were extracted before pre-operative orthodontic treatment. The second-stage procedure comprised anterior maxillary alveolar segmental osteotomy and Le Fort I osteotomy, sagittal splitting ramus osteotomy, anterior mandibular segmental osteotomy and genioplasty. Facial profile was significantly improved. Overjet changed from 15mm to 4mm, and occlusal stability was established. Maxillo-mandibular widening by distraction osteogenesis proved to be both aesthetically and functionally successful, with minimum extraction of teeth.

抄録全体を表示