Alveolar bone loss around mandibular anterior teeth in Class I, II, and III malocclusions: a CBCT evaluation study

Background: To quantitatively and qualitatively evaluate alveolar defects of mandibular anterior alveolar bone in three different types of malocclusion with cone-beam computed tomography (CBCT). Methods: A total of 542 teeth from 30 skeletal class I malocclusion (mean age: 19.26±5.63), 33 class II malocclusion (mean age: 19.36±4.17), and 28 class III malocclusion (mean age: 21.47±4.53) patients were evaluated with CBCT. Sagittal sectional views were evaluated with regard to labial and lingual alveolar bone thickness and vertical alveolar bone level. Analysis of variance and Tukey’s test were used for statistical comparisons at P<.05 Results: Qualitative analysis: Class II (64.47%) and Class III malocclusions (58.43%) had higher prevalence of dehiscence than Class I malocclusions (32.96%), P <0.05. No significant difference was found in the prevalence of fenestration among the three groups. Quantitative analysis: In general, Class II and III groups had lesser alveolar bone volume than the Class I group. Furthermore, the vertical alveolar height and coronal alveolar bone thickness in Class II malocclusion was significantly lesser than that in the Class III group. Conclusions: The Class II group, followed by the class III group, showed the most severe alveolar bone deficiency For these patients undergoing orthodontic treatment, special care should be taken to avoid aggravated preexisting alveolar bone loss in the mandibular anterior teeth.