This study examined the relations between degree of posterior dental compensation and skeletal discrepancy in Class III malocclusion. The pretreatment lateral cephalograms and dental casts of 87 skeletal Class III adults were selected to provide a random sampling of skeletal Class III malocclusion. Skeletal discrepancy was described with ANB angle, Wits appraisal, SN-Mn plane angle, FMA and ratios of basal arch width. Degree of posterior dental compensation was described with maxillary intermolar angle, mandibular intermolar angle and sum of intermoloar
angle. The relationships between skeletal discrepancy and degree of posterior dental compensation were analyzed with simple correlation analysis, stepwise multiple regression analysis.
The results were as follows :
I. A strong association was found between the variation in the anteroposterior measure, ANB angle and the variation of posterior dental compensation measures, sum of intenmolar angle and mandibular intermolar angle in skeletal Class III malocclusion.
2. There was no statistically significant relationship between the variation in the vertical measures and the variation
of posterior dental compensation measures in skeletal Class III malocclusion.
3. There was no statistically significant relationship between the variation in the anteroposterior and vertical
measures and degree, of basal arch width discrepancy.
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