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Updated: May 10, 2026
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A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible
Published on: January 28, 2020
Long-term 3-dimensional stability of mandibular advancement surgery
Alexandre A Franco1, Lucia Helena S Cevidanes, Ceib Phillips
1Department of Orthodontics, School of Dentistry, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
Summary
Mandibular advancement surgery is stable, but about 20% of patients experience 2-4mm changes in chin or condyle position one to three years post-operation. This study tracked these 3D skeletal changes.
Area of Science:
- Orthognathic surgery
- Craniofacial anatomy
- Skeletal stability
Background:
- Mandibular advancement surgery (MAS) is a common procedure for skeletal Class II malocclusions.
- Assessing long-term skeletal stability after MAS is crucial for treatment outcomes.
Purpose of the Study:
- To evaluate 3-dimensional positional and bone remodeling changes in the condyles, rami, and chin.
- To assess changes from 1 to 3 years after mandibular advancement surgery.
Main Methods:
- Prospective observational study of 27 patients with skeletal Class II jaw relation.
- Cone-beam computed tomograms (CBCT) used for pre- and postoperative analysis.
- 3D color maps and statistical analysis quantified positional and remodeling changes.
Main Results:
- The chin showed downward and backward rotation in 17% of cases (≥2mm change).
- Mandibular condyles exhibited displacements or bone remodeling (≥2mm) in 13-21% of cases.
- Rami displacements were observed in 4% of cases.
Conclusions:
- While MAS is generally stable, significant positional changes occur in approximately 20% of patients 1-3 years post-surgery.
- Adaptive bone remodeling and positional changes in the chin and condyles are common findings.
- Long-term 3D analysis reveals subtle but measurable skeletal alterations after mandibular advancement.
