Effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.

Objective: To evaluate the effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.

Materials And Methods: A total of 154 patients with at least two or more congenitally missing teeth were selected and divided into two groups (group I [mild]: patients with two to five missing teeth; group II [severe]: patients with six or more missing teeth). The patients with hypodontia were divided into three groups according to the location of missing teeth in the dental arches (anterior, posterior, and both anterior and posterior) and location of missing teeth between the jaws (maxilla, mandible, and both maxilla and mandible). Fifty Class I patients without any missing teeth served as the control group. Twenty-one measurements were performed on lateral cephalograms. Intergroup differences for the severity and location of hypodontia were analyzed using analysis of variance (ANOVA) and post-hoc Tukey tests.

Results: Significant decreases were found in mandibular plane angles (P < .05), upper and lower incisor measurements (P < .05), anterior (P < .001) and posterior (P < .05) face heights, and ramus height (P < .01), as well as a significant increase in the soft tissue convexity angle (P < .05) among the hypodontia groups and control group. These differences were more excessive in the severe hypodontia group. Upper lip-E plane measurements were significantly longer in the mandible group than in the maxilla group (P < .01).

Conclusions: Patients with congenitally missing teeth have different craniofacial morphologies. The severity and location of missing teeth have a significant effect.