Skeletal stability following maxillary impaction and mandibular advancement

• Published in: International journal of oral and maxillofacial surgery Vol. 33; no. 7; pp. 656 - 663
• Main Authors: Arpornmaeklong, P., Shand, J.M., Heggie, A.A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2004; Elsevier
• Subjects: Adolescent; Adult; bimaxillary osteotomy; Biological and medical sciences; Cephalometry - statistics & numerical data; Class II malocclusion; Dentistry; Facial bones, jaws, teeth, parodontium: diseases, semeiology; Female; Humans; internal fixation; Jaw Fixation Techniques; Male; Malocclusion, Angle Class II - surgery; Mandibular Advancement; Mandibular Condyle - pathology; Medical sciences; Non tumoral diseases; Osteotomy, Le Fort; Otorhinolaryngology. Stomatology; Recurrence; Retrospective Studies; stability; Treatment Outcome; Vertical Dimension; bimaxillary osteotomy; internal fixation; Class II malocclusion; stability; Human; Mandible; Stability; Superior maxillary; Osteotomy; Stomatology; Dental disease; Treatment; Surgery; Malocclusion; Bone
• ISSN: 0901-5027; 1399-0020
• DOI: 10.1016/j.ijom.2004.01.004

The purpose of this study was to retrospectively evaluate the stability of combined Le Fort I maxillary impaction and mandibular advancement performed for the correction of skeletal Class II malocclusion. Twenty-nine patients, mean age 22.6 years, underwent bimaxillary surgery with rigid internal fixation. Standardised cephalometric analyses were performed using serial lateral cephalometric radiographs. The post-surgical follow-up was a minimum of 12 months, with a mean of 25.2 months. The maxilla was impacted by a mean of 4.3±3.3 mm, and horizontally advanced by a mean of 2.6±2.3 mm. The results demonstrated that the maxilla tended to move anteriorly and inferiorly but this was not significant in either horizontal or vertical planes ( P>0.05). The mean advancement of the mandible, at menton, was 10.7±5.6 mm, and in 14 cases (48.2%) menton was advanced greater than 10 mm. In 34.7% of the patients the mandible underwent posterior movement between 2 and 4 mm. In the vertical plane, gonion moved superiorly by a mean of 2.7±3.6 mm which was significant. Significant mandibular relapse was found to have occurred in five female patients, with high mandibular plane angles who had undergone large advancements of greater than 10 mm. In conclusion, the majority of patients undergoing bimaxillary surgery for the correction of skeletal Class II malocclusions maintained a stable result. However, a small number of patients, exhibiting similar characteristics, suffered significant skeletal relapse in the mandible secondary to condylar remodelling and/or resorption.