A cross-sectional analysis of Wits and Riedel in adults with skeletal III malocclusion: How informative are they?

OBJECTIVES: To compare the relationship between Riedel and Wits appraisal in skeletal III malocclusions and to assess the effect of variation in the vertical skeletal measurements.

SETTING AND SAMPLE POPULATION: One-hundred and twenty consecutive subjects with Class III malocclusions attending orthognathic clinics were analysed.

MATERIALS AND METHODS: Lateral cephalograms were hand-traced under standardized conditions. Cephalometric measurements included Riedel analysis, Wits appraisal, A point/B point to Frankfurt plane (AF-BF) and vertical measurements.

RESULTS: The mean ANB and Wits values were -3.22° and -11.39 mm, respectively. A positive correlation was found between ANB and Wits overall (r = -.49; P < .001). However, there was poor agreement between both Wits (r = .087) and Riedel (r = .089) with AF-BF (P > .05). A negative correlation existed between Wits and LAFH% (r = -.64, P-value < .001); however, no relationship was observed between ANB and LAFH% (P > .05) based on linear regression analysis.

CONCLUSIONS: There is a positive relationship between ANB and Wits; however, neither correlated well with a purer antero-posterior assessment (AF-BF). Furthermore, variations in the vertical skeletal measurements affect the strength of agreement. Caution is advised in the interpretation of antero-posterior analysis especially in the presence of vertical discrepancy.