Stability of skeletal Class III malocclusion after combined maxillary and mandibular procedures: titanium versus resorbable plates and screws for maxillary fixation.

PURPOSE: The aim of this study was to evaluate skeletal stability after double jaw surgery for correction of skeletal Class III malocclusion to assess if there were any differences between resorbable plate and screws and titanium rigid fixation of the maxilla. PATIENTS AND METHODS: Twenty-two Class III patients had bilateral sagittal split osteotomy for mandibular setback stabilized with rigid internal fixation. Low level Le Fort I osteotomy for maxillary advancement was stabilized with conventional titanium plate and screws in 12 patients (group 1) and with resorbable plate and screws in 10 patients (group 2). Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively.
RESULTS: Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary stability was excellent in both groups. In group 1 no significant correlations were found between maxillary advancement and relapse. In group 2, significant correlations were found between maxillary advancement and relapse at A point and posterior nasal spine. No significant differences in postoperative skeletal and dental stability between groups were observed.
CONCLUSION: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure for maxillary advancements up to 5 mm independently from the type of fixation used to stabilize the maxilla. Resorbable devices should be used with caution for bony movements of greater magnitude until their usefulness is evaluated in studies with large maxillary advancements.