Prevalence and patterns of tooth agenesis in Angle class II division 2 malocclusion in Italy: A case-control study

Objective: The aim of this case-control retrospective study was to assess the prevalence and pattern of tooth agenesis in a group of Italian Caucasian test subjects with Class II division 2 malocclusion. The findings were then compared with an Italian control group of orthodontic patients and with previous studies performed in other countries. Material and method: Six hundred patients (37 subjects with Angle Class II division 2 malocclusion and 563 orthodontic patients with other malocclusions), aged 7 or older, from the Orthodontic Department of University of Padua Dental Clinic were collected. For this investigation, two expert operators evaluated the Angle Class from dental casts, intraoral photographs and lateral cephalograms. Inclusion criteria for Class II division 2 were: U1-SN less than 90° and overbite > 3 mm. Tooth agenesis were assessed with digital panoramic radiographs. Third molars were excluded from the analysis. Descriptive analysis using absolute and relative frequencies were performed to check out the prevalence and pattern of tooth agenesis in the sample considered. The relative frequencies in each table were calculated as a percentage based from column total. Results: The prevalence of tooth agenesis in the Angle Class II division 2 group was 18.92%, while in the general population was 8.35%. This result was sufficient to demonstrate a significant difference between the two groups concerning the tooth agenesis prevalence (P-value < 0.05). Conclusion: Prevalence of permanent tooth agenesis was more than 2 times higher in the Class II division 2 group rather than in the control group. No agenesis of maxillary lateral incisors was found in Class II division 2 group.