Prevalence and Patterns of Non-syndromic Hypodontia in Permanent Dentition among the Nepalese Population: A Radiographic Study and Literature Review

Introduction Odontogenesis is a complex process involving interactions between odontogenic and ecto-mesenchymal cells, mediated by growth factors and signaling pathways. Disruptions in these pathways lead to various dental anomalies. This study aimed to evaluate the prevalence and patterns of non-syndromic hypodontia among the Nepalese population. Methods A total of 5,075 panoramic radiographs taken between 2012 and 2020 were retrospectively reviewed. The mean age of the study subjects was 20.17 ± 5.51 years (range: 8 to 40 age), comprising 1,805 males (35.56%) and 3,270 females (64.43%). Hypodontia was diagnosed based on the absence of crown calcification of permanent teeth. Prevalence, distribution, and symmetry of hypodontia were assessed, with categorical associations analyzed using the Chi-square test ( p <0.05). Results The study analyzed 5,075 panoramic radiographs, consisting of 1,805 males (35.56%) and 3,270 females (64.43%). Hypodontia was identified in 400 subjects, 200 males (50%) and 200 females (50%), representing 7.88% of the population. A total of 655 missing teeth were recorded, 45.8% in females and 54.2% in males. Despite an equal number of affected males and females, a statistically significant association was found between gender and overall hypodontia prevalence in the sample ( p < 0.05), with males showing a higher likelihood of being affected. Maxillary lateral incisors were the most affected (47.33%), followed by mandibular second premolars (19.08%) and maxillary first premolars (17.56%). The maxillary arch had a significantly higher prevalence of hypodontia than the mandibular arch ( p < 0.05). Unilateral hypodontia was more prevalent than bilateral hypodontia ( p < 0.05). The most common associated dental anomalies were rotated adjacent teeth and retained deciduous teeth, but they were not statistically significant ( p > 0.05). Conclusion The prevalence of hypodontia among the Nepalese population was 7.8%. The findings of this study align with global trends, particularly the higher frequency of hypodontia in the maxillary lateral incisors.