Orthognathic Surgery In Skeletal Class Research Articles

Late Growth Period Orthopedic Therapy Versus Bimaxillary Surgery for Correction of Skeletal Class III

To compare the effects of late orthopedic therapy with orthognathic surgery in skeletal class III cases. The subjects of the study were divided into 2 groups. Group 1 comprised 15 patients (8 females and 7 males) with a mean age of 14 years 6 months (range, 12 y 10 mo to 15 y 6 mo) and treated with maxillary expansion and a modified maxillary protraction appliance (MMPA). Group 2 comprised 11 patients (6 females and 5 males) treated with bimaxillary surgery (BMS) with a mean age of 23 years (range, 18 y 2 mo to 28 y 4 mo). Lateral cephalometric films were taken before (T1) and after orthopedic therapy (T2) in the MMPA group and before surgery (T1) and after fixed orthodontic therapy (T2) in the BMS group. Study groups were compared by analysis of variance and Tukey tests at the beginning and at the end of the treatment. Maxillary forward displacement (P < 0.01) and the increase in ANS-Me distance (P < 0.05) were higher in the BMS group than in the MMPA group. The mandible exhibited significant posterior rotation in MMPA group (P < 0.01). Mandibular effective length decreased in the BMS group and increased in the MMPA group. Soft tissue profile (G-Sn-Pg) improved in both groups (P < 0.05) and labiomental angle reduced in the BMS group, whereas an increase was observed in the MMPA group. Orthognatic surgery can be more effective in patients with increased mandibular length, more anteriorly positioned mandibles, and increased vertical dimensions.

The structural change in the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients using 3-dimensional computed tomography

The structural change in the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients using 3-dimensional computed tomography

Changes of Serum Biochemical Markers during Bone Repair just after Orthognathic Surgery

The purpose of this study was to elucidate changes in serum biochemical markers related to bone turnover after orthognathic surgery in skeletal Class III patients. The subjects consisted of 16 healthy, adult men aged 22.1 to 40.3 years, one week before surgery. Samples of venous blood (5–6 mL) were taken at 10 : 00 a. m.–12 : 00 a. m.. The timing of each sample collection was: before-surg, one week before surgery; 3-d, three days after surgery; 10-d, ten days after surgery; 1-m, one month after surgery; 3-m, 3 months after surgery; and 6-m, 6 months after surgery. Serum osteocalcin, bone alkaline phosphatase (BAP), and tartrate-resistant acid phosphatase (TRAP) were measured at each stage. Additionally, serum C-reactive protein (CRP) and other serum components were measured as general examinations of bone metabolism and for health checks. Results: 1. Among all values of serum components during the observation period, only CRP at 3-d was higher than the standard value for Japanese adults. 2. Serum osteocalcin (p<0.001 and TRAP (p<0.01 showed a significant decrease at 3-d versus before-surg, and recovered after 10-d. Serum BAP showed significant decreases at 3-d (p<0.001 and 10-d (p<0.01 versus before-surg and recovered after 1-m. 3. Serum CRP increased significantly at 3-d (p<0.001 versus before-surg beyond the normal range, but returned to normal levels after 10-d. Conclusion: Each early fall at 3-d in serum osteocalcin, BAP, and TRAP seemed to reflect the suppression of bone metabolism due to the stress of orthognathic surgery.

骨格性下顎前突症患者における口唇周囲軟組織の三次元運動解析

Aim: The purpose of this study was to introduce our newly developed three-dimensional system of analyzing the lip movement synchronized with mandibular movement and to analyze the relationships between lip movement and mandibular movement before and after orthognathic surgery in skeletal Class III patients using this system.Materials and Methods: The subjects comprised 8 skeletal Class III patients who had undergone bilateral sagittal splitting mandibular ramus osteotomy and 8 persons with individual normal occlusion. Materials consisted of three-dimensional movement values obtained by a motion capture system equipped with two infrared CCD cameras, and three-dimensional static values measured by the three-dimensional optical laser scanner. Four landmarks affixed on the soft tissue around the mouth and four other landmarks to estimate the lower incisor movement were measured for 30 seconds during habitual mouth opening and closing movement. The relationships between lip movement and the lower incisor movement were compared between the pre-and post-operation and the normal groups.Results: The system developed in this study enabled three-dimensional measurement of lip and lower incisor movements during habitual mouth opening and closing at the same time. The landmarks on the lower lip, the right and left angles of the mouth and the chin point moved further in the pre-operation group than those in the post-operation and normal groups during habitual mouth opening and closing. Three-dimensional movement values after surgery showed a tendency to be close to those in the normal group.Conclusion: The present system may be useful for accurately measuring the movement of the lip synchronized with the lower incisor movement. Post-operative smooth movement of the soft tissue around the mouth suggests that tension of the muscles between the hard and soft tissues observed before surgery might decrease after surgery.

The changes of the masticatory efficiency following orthognathic surgery in skeletal Class III patients—Longitudinal study by means of ATP absorbance method : Hara T, Sugawara J, Mitani H, et al. J Jpn Orthod Soc 53:66, 1994

The changes of the masticatory efficiency following orthognathic surgery in skeletal Class III patients—Longitudinal study by means of ATP absorbance method : Hara T, Sugawara J, Mitani H, et al. J Jpn Orthod Soc 53:66, 1994

The Study of Long-term Dentofacial Stubility Following Two-Jaw Surgery

The purpose of this study was to investigate long-term dentofacial stability after two-jaw orthognathic surgery in skeletal Class III malocclusion. Fourteen subjects, 12 females and 2 males, who had undergone two-jaw surgery at Tohoku University Dental Hospital were used in this study. Each patient had at least a five-year of post operative observation period. The frontal and lateral cephalometric radiographs were used for quantitative evaluation of dentofacial stability. The materials were taken seven times from the initial examination for 5 years postoperatively.The results of this study were as follows:1. Excellent postoperative stability was observed at the maxilla three-dimentionally.2. Although antero-posterior displacement of the manbible after debonding was minimal, moderate relapse tendencies were observed vertically. Especially, significant reduction of lower facial height and Go to Or distance caused relapse in some patients.3. Appropriate overjet has been maintained in most of the cases. But there was a tendency to decrease in overbite during the long-term observation period. However, none of the patients showed reversed occlusion or openbite at the latest examinations.In conclusion, the results of this study indicated the following conditions to maintain long-term dentofacial stadibility after two-jaw surgery; 1) to establish a treatment planning to prevent vertical relapse of the mandible, 2) if necessary, to reconstruct the physiological occlusion by prosthetic treatment, and 3) to activate organs and tissues associated with the masticatory system by means of functional therapy and training.