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LeFort I maxillary advancement: 3-year stability and risk factors for relapse.Dowling PA, Espeland L, Sandvik L, Mobarak KA, Hogevold HE Department of Public and Child Dental Health, Trinity College, Dublin, Ireland. 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. Published 15 November 2005 in Am J Orthod Dentofacial Orthop, 128(5): 560-7; quiz 669.
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