Three-year stability of open-bite correction by 1-piece maxillary osteotomy.

INTRODUCTION: The purpose of this retrospective cephalometric study was to evaluate the long-term vertical stability of anterior open-bite correction by 1-piece Le Fort I osteotomy and rigid fixation. METHODS: The sample comprised 40 consecutively treated patients from the files of the Department of Orthodontics, University of Oslo, Norway. All subjects had received a 1-piece Le Fort I osteotomy as the only surgical procedure from 1990 through 1998 and were followed for 3 years according to a protocol for data collection. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery. RESULTS: The mean open bite before surgery was 2.6 mm; at the 3-year follow-up, 35 patients had a positive overbite, and the remaining 5 patients had an open bite between 0.2 and 0.9 mm. Impaction of the posterior maxilla >or=2 mm relapsed on average by 31%, and inferior repositioning of the anterior maxilla >or=2 mm relapsed by 62%. Maxillary vertical skeletal changes during the postsurgery period were compensated for by orthodontic dentoalveolar adaptation. Most of the skeletal relapse occurred during the first 6 months after surgery and always in the direction opposite to the surgical movement. The relative contribution of mandibular and maxillary changes in anterior open-bite closure was approximately 3:1. CONCLUSIONS: Surgical correction of anterior open bite was generally stable over a 3-year period, and skeletal relapse was counteracted by dentoalveolar compensation.

Long-term skeletal and soft-tissue responses after advancement genioplasty.

INTRODUCTION: The objectives of this cephalometric study were to assess the skeletal stability of advancement genioplasty 3 years after surgery and to evaluate the predictability of soft-tissue changes. METHODS: The subjects comprised 21 consecutive patients who had no additional orthognathic surgical procedures. Lateral cephalograms were taken at 5 times: immediately preoperative, immediately postoperative, 6 months postoperative, and 1 and 3 years postoperative. RESULTS: Mean surgical advancement at pogonion was 8.4 mm. Three years after surgery, mean relapse at pogonion was 8% of the surgical advancement. Part of this change was most likely due to bone remodeling. No patient demonstrated a clinically significant postoperative change at pogonion. The soft tissue of the chin was found to follow bony movement in a ratio of 0.9:1. Great individual variability was observed. The mentolabial fold depth increased as a result of the treatment. Effects of advancement genioplasty on the lips were small. CONCLUSIONS: A prediction ratio based on long-term skeletal changes is likely to generate an estimate that is more appropriate to present to the patient.

LeFort I maxillary advancement: 3-year stability and risk factors for relapse.

INTRODUCTION: The objectives of this retrospective cephalometric study were to assess the amount, direction, and timing of postoperative changes after LeFort I maxillary advancement, and to identify risk factors for skeletal relapse. METHODS: The material was selected from the files at the Department of Orthodontics, University of Oslo, and comprised 43 patients who underwent 1-piece LeFort I advancement as the only surgical procedure from 1990 to 1998. All patients were followed for 3 years by using a strict data collection protocol. Lateral cephalograms were obtained before surgery and at 5 times after surgery. RESULTS: A mean relapse of 18% of the surgical advancement occurred. In 14% of the patients, clinically significant skeletal relapse (> or = 2 mm) was observed. Most (89%) postoperative change occurred during the first 6 months after surgery. Skeletal relapse increased significantly with degree of surgical advancement (P = .001) and degree of inferior repositioning of the anterior maxilla (P = .004) (linear regression analysis). At the end of follow-up, overjet and overbite were within clinically acceptable ranges for all patients. CONCLUSIONS: Maxillary advancement with a 1-piece LeFort I osteotomy is a relatively stable procedure. Identified risk factors for horizontal relapse were degree of surgical advancement and degree of inferior repositioning of anterior maxilla.