The Reliability of the Wits Appraisal Using Maxillo - Mandibular Angle Bisector Reference Plane in Skeletal Normal Bite Patients

Abstract

Objectives: This research aimed to detect the reliability of the Wits appraisal using maxillo - mandibular angle bisector reference plane by compared with the traditional Wits appraisal using functional occlusal reference plane, in addition, the cant of maxillo - mandibular angle bisector plane was observed in skeletal normal bite patients.
Materials and Methods: Lateral cephalograms of 120 skeletal normal bite patients were selected. The subjects were divided into 3 groups by sagittal skeletal Classes. Each group comprised 40 subjects (20 males and 20 females). Measurements were made to consider the correlation between the Wits appraisal using 2 different reference planes with the ANB angle.
Results: The Wits appraisal using maxillo - mandibular angle bisector reference plane correlated with the ANB angle in all 3 sagittal skeletal Classes. The correlation coefficients were 0.53 (p < 0.01), 0.51 (p < 0.01) and 0.56 (p < 0.01) in skeletal Class I, Class II, and Class III, respectively. The Wits appraisal using functional occlusal reference plane correlated with the ANB angle only in skeletal Class II and Class III. The correlation coefficients were 0.41 (p < 0.01) and 0.56 (p < 0.01) in skeletal Class II and Class III, respectively. The maxillo - mandibular angle bisector plane located closely, inferior, downward slant anteriorly related to the functional occlusal plane.
Conclusions: The Wits appraisal using maxillo - mandibular angle bisector reference plane correlated with the ANB angle in all 3 sagittal skeletal Classes, so it could be a more reliable indicator for the assessment of sagittal skeletal discrepancies than the traditional Wits appraisal using functional occlusal reference plane in skeletal normal bite patients.