Partial Necrosis of the Mandibular Proximal Segment Following Transoral Vertical Ramus Osteotomy / 대한악안면성형재건외과학회지

Transoral vertical ramus osteotomy (TOVRO) procedure can result in a variety of complications. Complications commonly reported include extensive bleeding due to major blood vessel injury, unpredictable fracture, postoperative infection, neurosensory deficit related Inferior alveolar nerve, insufficient osteosynthesis, and temporomandibular joint problem. The authors describe a case of partial necrosis of the mandibular proximal segment following TOVRO, a rarely reported complication. A 37-year-old otherwise healthy woman underwent Lefort l osteotomy and TOVRO to correct mandibular prognathism. Postoperatively, she developed pain and swelling in the right submandibular region and was found to have a partial necrosis of proximal segment.

Long-term results of vertical height augmentation genioplasty using autogenous iliac bone graft

PURPOSE: In order to clarify the clinical utility of the vertical height augmentation (VHA) genioplasty using autogenous iliac bone graft (IBG), this study examined the postsurgical changes in hard and soft tissues of the chin and the stability of the grafted bone. PATIENTS AND METHODS: Twenty-three patients who had undergone VHA genioplasty using autogenous IBG were evaluated radiographically and clinically. A comparison study of the changes in hard to soft tissues after surgery in all 23 patients was performed with preoperative, 1-month, 3-months, 6-months, and/or 1-year postoperative lateral cephalograms by tracing. Stability, bone healing, and complication of the grafted bone was evaluated by follow-up roentgenograms and clinical observation. RESULTS: Between the preoperative and 6-month postoperative tracings, an average vertical augmentation of the osseous segment was 4.2 mm at menton and that of the soft tissue menton was 4.0 mm. There was a high predictability of 1: 0.94 between the amounts of hard versus soft tissue changes with surgery in the vertical plane. The position of the genial bone segment was stable immediately after surgery and soft tissue was not changed significantly from 1 month to 1 year after operation. Clinical and radiological follow-up results of the iliac bone graft showed normal bony union and were generally stable. CONCLUSIONS: VHA genioplasty using IBG is a reliable method for predicting hard and soft tissue changes and for maintaining postoperative soft tissue of the chin after surgery.

An anatomical study of the mandibular ramus in Korean patients with dentofacial deformity

Orthognathic surgery of the mandibular prognathism and the retrognathism is tend to be performed on the mandibular ramus to prevent inferor alveolar nerve injuries. The purpose of this study is to find a safe and accurate reference point on mandibular ramus for orthognathic surgery by comparative anatomical study of dentofacial deformity patients. We use 38 Korean Cadavers with normal occlusion(Group 1), 3-dimensional simulation of computerized tomogram of 23 patients with retrognathism (Group 2), 27 patients with mandibular prognathism (Group 3). Following results are obtained : 1. The maximum thickness of the mandibular ramus is 8.78+/-1.15mm for Group 2, 7.61+/-1.26mm for Group 1, 6.95+/-0.82mm for Group3 respectively (P=0001). The minimum thickness is 5.51+/-1.08mm for Group 1 , 5.06+/-0.40mm for Group 2, 4.56+/-0.78mm for Group3, respectively (p=0.0001). But, the thickness at the level of 5mm above the lingular is 0.78+/-0.65mm for Group 2, 5.63 +/-1.28mm for Group 1, 5.32+/-0.91mm for Group 3, respectively. There is no significant difference between these groups(P=0.0510). 2. The horizontal location from the midwaist point to lingular is 0.18+/-1.57mm for Group 1, 0.69+/-1.33mm for Group 2, 0.66+/-1.66mm for Group 3, and there is no significant difference between these groups(p=0.0835). But the vertical location from the midwaist point to lingular is 1.45+/-2.64mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is significant difference between these groups(p=0.0030). 3. The horizontal location from the midwaist point to mandibular foramen is 0.29+/-1.75mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is no significant difference between these groups(p=0.5403). But the vertical location from the midwaist point to mandibular foramen is -3.33+/-4.43mm for Group1, -4.79+/-2.26mm for Group 2, -6.06+/-2.99mm for Group 3, and there is significant difference between these groups(P=0.0001). 4. The horizontal length from the disto-buccal cusp tip of mandibular second molar to lingula is 30.97+/-4.17mm for Group 3, 28.29+/-2.65mm for Group 1, 25.48+/-0.77mm for Group 2 (p=0.0000), and also vertical length is 7.72+/-3.22mm for Group 3, 6.38+/-1.83mm for Group 1, 5.89+/-2.30mm for Group 2 (P=0.0014). 5. The location of lingular is 0.50 from anterior border of mandibular ramus in all groups, if it assumed the length from anterior border to posterior border is 1. And it is almost 0.33 from the sigmoid notch, if it assumed the length from sigmoid notch to antegonial notch is 1. 6. In Group 1, Antilingular prominence is located on (1.12+/-1.43mm, 4.01+/-2.36mm) from the midwaist point, and there is no correlation between antilingular prominence and lingular, mandibular foramen.

A clinical study on openbite & relapse tendency after IVRO of the mandibular prognathism

IVRO is one of the most common procedures to setback prognathic mandible. Since 1993 we have set-up our own protocol for functional physiotherapy(Park's protocol) after IVRO. This is a study on openbite and relapse tendency after IVRO followed by our protocol. We obtained lateral cephalograms of twenty-seven patients which were taken immediately after surgery, 3 months, 6 months and 1 year postoperatively. Changes in positions of each point were analyzed. The results were as follows: 1. No remarkable openbite occured during the first year after IVRO. Upper teeth, lower teeth and anterior mandible moved upward, it seems to show that post-op orthodontic treatment did not contribute to reduce openbite tendency during post-op period. Rater, the lower teeth and mandible moved with the upper teeth as the compensation mechanism. 2. Lower Incisal Edge moved anteriorly up to 6 months, so overjet decreased from 3.3mm to 2.9mm during the first six months. Skeletal changes in anterior mandible showed slight anterior movement, therefore showing slight relapse tendency, but it represented no statistical significance. 3. The physiotherapy according to our protocol was used for only a month after operation, but there was no openbite tendency, and the occlusion was stable over one year.