Condylar direction as a predictor of treatment outcome in mandibulra retrognathism.

AIM: To investigate the position of the glenoid fossa in subjects with Class II and Class III malocclusions to clarify the role of this craniofacial component in sagittal skeletal disharmonies. SUBJECTS AND METHOD: Thirty subjects with dentoskeletal Class III malocclusions associated with mandibular protrusion, and 30 subjects with dentoskeletal Class II malocclusions associated with mandibular retrusion, both aged 8 years ±6 months, with normal skeletal vertical relationships, and normal mandibular dimensions, were compared with a control group of 33 subjects with dentoskeletal Class I relationships. The comparisons between the Class II and Class III groups and the control group on the cephalometric measurements for the assessment of glenoid fossa position were performed with a Mann-Whitney U test, P < 0.05. The power of the study exceeded 0.90. RESULTS: Subjects with a Class III malocclusion presented with a significantly more mesial position of the glenoid fossa, while those with a Class II disharmony showed a significantly more distal position of the glenoid fossa when compared with the control group as measured by means of three parameters (GF-S on FH, GF-Ptm on FH, and GF-FMN). CONCLUSIONS: An anomalous sagittal position of the glenoid fossa is a possible diagnostic anatomical feature of Class II and III malocclusions associated with mandibular retrusion and protrusion, respectively. An effective measurement to evaluate glenoid fossa position within the craniofacial relationships is the cephalometric distance from the glenoid fossa to the fronto-maxillo-nasal suture (GF-FMN), which also showed the least measurement error.