The influence of mild versus severe hypodontia on facial soft tissues? A three-dimensional optical laser scanning-based cohort study.

To determine whether there are differences in the facial soft tissue morphology between participants with mild (up to two) or severe (six or more) hypodontia. A prospective hospital-based cohort study. Ninety-two participants, aged 11-16 years, with confirmed hypodontia were recruited. Participants were sub-grouped based on the severity (mild, two or less and severe, six or more) and distribution of the missing teeth and age. They underwent a three-dimensional (3D) optical surface scan of the facial soft tissues. Facial surface scans were compared quantitatively, applying landmark measurements and surface-based analysis. In total, 92 participants, with an equal distribution between the mild (n=46) and severe (n=46) categories, were recruited. Patients with severe hypodontia displayed a reduced alar base, lower facial height, nasolabial angle ( Significant reductions were seen in the 3D soft tissue morphology of participants with severe hypodontia, in terms of the nasolabial angle, lower facial height, alar base and transgonial widths, emphasising the importance of using facial scanning as a relatively simple non-invasive method of assessment.