A Novel Imaging Technique for Analyzing Condylar Movement During Mastication in Patients With Jaw Deformities: Four-Dimensional Computed Tomography.

OBJECTIVE: This study aimed to reveal characteristic condylar movements in patients with jaw deformities. STUDY DESIGN: Thirty patients with jaw deformities before surgery were enrolled and instructed to chew a cookie during 4-dimensional computed tomography (4DCT). The distance between the most anterior and posterior positions of the bilateral condyles on 4DCT images was measured and compared among patients with different skeletal classes. Correlations between the condylar protrusion and cephalometric values were also determined. RESULTS: The distances of condylar protrusion during mastication were significantly greater in the skeletal class II group than in the skeletal class III group ( P =0.0002). Significant correlations were found between the distances of condylar protrusion during mastication and the sella-nasion-B point angle ( r =-0.442, P =0.015), A point-nasion-B point angle ( r =0.516, P =0.004), sella-nasion plane to ramus plane angle ( r =0.464, P =0.01), sella-nasion plane to occlusal plane angle ( r =0.367, P =0.047), and condylion-gonion length ( r =-0.366, P =0.048). CONCLUSION: Motion analysis with 4DCT images revealed that condylar movement in patients with retrognathism was larger than in patients with mandibular prognathism. Skeletal structure was therefore correlated with condylar movement during mastication.

Effect of low-intensity pulsed ultrasound after intraoral vertical ramus osteotomy.

OBJECTIVE: The present study investigated the effect of low-intensity pulsed ultrasound (LIPUS) on long-term osseous healing of the cleavage space between bone fragments after intraoral vertical ramus osteotomy (IVRO). STUDY DESIGN: Patients undergoing IVRO were randomly assigned to the LIPUS group (n = 12) or the control group (n = 9) after surgery. LIPUS treatments were applied daily to the cleavage space between bone fragments for 3 weeks. We observed 3-dimensional quantitative color mapping of the whole mandible created by computed tomography (CT) data at 1 month, 6 months, and 1 year postoperatively. On the basis of CT values, the color grades were classified as D1 to D5 by using the Misch criteria. We then calculated mean CT values and rated each color grade in different selection ranges. RESULTS: The mean CT values of the LIPUS group were significantly higher than those of the control group at 1 month, 6 months and 1 year postoperatively (P < .01). The color grades of the cleavage between bone fragments increased from D5 to D1 over time. CONCLUSIONS: Our results indicated that LIPUS promoted osseous healing after IVRO, thus improving bone density and offering clinical benefits.

Observation of osseous healing after intraoral vertical ramus osteotomy: focus on computed tomography values.

PURPOSE: The purpose of this study was to observe long-term osseous healing of the cleavage space between bone fragments after intraoral vertical ramus osteotomy using computed tomographic (CT) values. PATIENTS AND METHODS: CT examinations were performed to observe long-term osseous healing immediately after intraoral vertical ramus osteotomy and at 6 months, 1 year, and 2 years postoperatively. Bone fragments were observed on the interior and lateral sides. CT values between bone fragments were used to measure the range of each point within a 1.7- × 1.7-mm square, and the mean of the measurements was calculated. RESULTS: CT values between bone fragments increased significantly over time at 1 month, 6 months, 1 year, and 2 years after surgery. CONCLUSIONS: Osseous healing in the cleavage between bone fragments after intraoral vertical ramus osteotomy was successful according to CT values.

Orthognathic surgery for occlusal reconstruction of old malunited jaw fracture.

Old malunited jaw fractures of nine patients who underwent orthognathic surgery for occlusal reconstruction were clinically evaluated. Early surgery on fractures of the jaw is the optimal treatment when due attention must be paid to occlusion. Since occlusal revision surgery subsequent to inaccurate diagnosis and inappropriate surgery is certainly very difficult and often unsuccessful, surgeons need to pay special attention to this situation.

Occlusal reconstruction: orthodontic techniques for treatment of jaw fracture.

AIM: Treatment by the multidisciplinary-team approach for jaw fractures, and the role of the orthodontist, are discussed and illustrated through case reports. METHODS: Two cases of jaw fractures treated with orthodontic techniques, as an alternative noninvasive procedure, are presented. One subject with a fresh mandibular fracture did not consent to surgery, despite a good indication for open reduction. The other subject had maljoined mandibular fractures from surgery, with insufficient occlusal consideration. CONCLUSION: Orthodontists, as well as oral surgeons, participate in every stage of the treatment of jaw fractures, including treatment decisions, in-patient management, dietary guidance, etc. Orthodontists also attend surgical operations to determine the most stable occlusion, making possible more detailed occlusal reconstruction.

Devices for facial aesthetic improvement in the treatment of skeletal mandibular protrusion.

Some techniques for the treatment of mandibular protrusion with consideration for aesthetic improvement of the face as a whole are described. The aesthetic inferiority complex in the mind of patients with masticatory disorders as the chief complaint should not be underestimated. Three techniques were used in this study; preoperative orthodontic treatment, preservation of the patient's self-image, and maintenance of beautiful relationship between the midfacial line and the nasolabial fold as well as the nasal ala.

Indications and procedures for segmental dentoalveolar osteotomy: a review of 13 patients.

The authors evaluated the surgical area, indications, and procedures for segmental dentoalveolar osteotomy carried out on 16 jaws in 13 patients treated at the Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, between 1990 and 2001. Osteotomy was indicated mainly in cases where tooth repositioning by orthodontic treatment was limited, where social conditions (e.g., age, time, finances) precluded orthodontic treatment, or where revision of orthodontic or surgical treatment was required. In cases of maxillary anterior segmental dentoalveolar osteotomy, the modified Wunderer method was used, where after an incision was made in the palatal mucosa, a mucoperiosteal flap was abraded as much as possible until the area of the osteotomy on the palatal side could be visualized. In maxillary posterior segmental dentoalveolar osteotomy, the operation was carried out in 2 stages because of the risk of necrosis of the bone fragments. In the first stage, an osteotomy was carried out on the vestibular side, since the vestibular gingival pedicle was intact. In the second stage, 3 weeks later, another osteotomy was performed after the palatal mucoperiosteal flap was abraded to visualize the area of the osteotomy as well as that of the maxillary anterior segmental dentoalveolar osteotomy.