The Relationship between Third Molar Agenesis and Gender, Residence Area and Class of Malocclusion

The aim of this study was to assess the prevalence of third molar agenesis and its relation with gender, home residence area and class of malocclusion. We took into study 250 orthodontic adolescent patients, 171 females and 79 males, with ages between 11-21 years. Dental age and third molar agenesis were evaluated on orthopantomograms and for the malocclusion class diagnostic was used the ANB angle measured on lateral cephalometric films. We found out that there is a strong correlation between chronological age and dental age $(\mathrm{R}^{2}=0.911)$ and third molar agenesis is present in 28% of the patients; females were more affected than males, with a ratio 4:3, but no statistically significance could be established. The number of patients in the rural showed slightly an increase in third molar agenesis (27.14%) compared with the patients in the urban area (22.78%), but no correlation was established according to residence place (p$\lt$0.05). Third molar agenesis is related to malocclusion, class I malocclusion patients had mostly one tooth missing, while class II and class III malocclusion patients presented multiple agenesis. These results suggest that third molar agenesis does not relate to the gender or residence area, but correlates with the class of malocclusion.