Abstract: Objective    To compare the sagittal inclination of anterior teeth and lengths of dental arch and basal bone arch  in skeletal malocclusions and to evaluate the relevance between these three variables.  Methods    One hundred and four  pretreatment CBCT data of subjects with skeletal Class I, II, III malocclusion and normal occlusion were collected. MATLAB software was used to measure the sagittal inclination of anterior teeth, lengths of dental arch and basal bone arch. The differences and correlation between the indexes were evaluated and analyzed.    Results    The sagittal inclination of anterior teeth in class III group was significantly less than in other three groups. The lengths of dental arch and basal bone arch in class III group were greater than in the other three groups. The sagittal inclination of incisors in class II group was significantly greater than in the other three groups. The sagittal inclination of anterior teeth was moderately negatively correlated with the lengths of the corresponding basal bone arch (r=-0.557,-0.554,-0.489 P<0.001), while the sagittal inclination of anterior teeth was not correlated with the length of dental arch. Conclusions    There were differences in sagittal inclination of anterior teeth, lengths of dental arch and basal bone arch  between different skeletal malocclusions. We can evaluate the sagittal growth of basal bone by sagittal inclination of anterior tooth. However, changing sagittal inclination of anterior tooth has little impact on the length of dental arch. 

Key words: Skeletal malocclusion; ,  , Sagittal inclination; ,  , Dental arch length; ,  ,  Length of basal bone arch