Agenesis of permanent teeth – a report based on cases from clinical practice at the Department of Orthodontics, Medical University of Warsaw

Introduction
Tooth agenesis (OMIM # 106600), i.e. the congenital lack of tooth buds, is the most common dental abnormality. The congenital lack of tooth buds is a consequence of disturbances in their initial development, at the stage of formation and proliferation. Genetic, epigenetic and environmental factors affect the development of this abnormality.

Aim
The aim of the work was to characterise a group of patients with the congenital lack of permanent tooth buds based on cases from clinical practice at the Department of Orthodontics, Medical University of Warsaw.

Material and methods
Material for the study was obtained from a database of the Department of Orthodontics, Medical University of Warsaw, and included a group of 712 patients, namely 430 women and 282 men. The study was conducted on the basis of an analysis of medical history charts and available additional examinations, namely radiological images and photographic documentation. The data obtained were subject to statistical analysis.

Results
In this group, agenesis was found in 60.4% of women, and 39.6% of men. The mean number of missing teeth in the maxilla was 3.15, in the mandible – 3.03, and in the maxilla and mandible together – 6.18.Hypodontia was observed in 58.2% (414 patients), oligodontia in 41.2% (293 patients), and anodontia in 0.7% (5 patients). The lack of lateral incisors in the maxilla (16.1% of missing teeth) and of second premolars in the mandible (15.5%) was observed the most frequently, followed by the lack of second premolars in the maxilla (12.7%) and of central incisors in the mandible (9.6%), and rarely of central incisors in the maxilla (1.3%).

Summary
Agenesis was more common in women and more common in the maxilla than in the mandible. Hypodontia was also more frequent than oligodontia. Anodontia of permanent teeth was observed the most rarely.