Presence of third molars in orthodontic patients from northern Greece

Georgia Barka,¹ Georgios Tretiakov,¹ Theodosios Theodosiou,² Ioulia Ioannidou-Marathiotou^3
1School of Dentistry, ²Biostatistics, Department of Informatics, School of Natural Sciences, ³Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece

Objective: The purpose of the present study was to investigate the frequency of presence of third molar teeth and their distribution in each jaw and each side, according to sex, in a group of orthodontic patients with permanent dentition from northern Greece.
Methods: The sample included panoramic radiographs from 220 patients with permanent dentition (mean age 13.62 ± 1.81). The Χ² test was used to assess the relationships between the variables, and the Fisher's exact test was used in cases where the expected frequencies in each cell were <5.
Results: The frequency of third molar presence was 79.1%, and 20.9% was the frequency of third molar agenesis. Intersexual differences in the number of third molars was not statistically significant. There was a correlation between the distribution of third molars on the right and the left side (Fisher's exact test = 100.788; P = 0). The two sides showed the same tendency toward the presence or absence of third molars. A correlation was also found between the distribution of maxillary and mandibular third molars (Fisher's exact test = 24.372; P = 0). In each jaw, the presence or absence of third molars was highly related to the number of third molars found in the other jaw.
Conclusion: The present results showed that in this orthodontic group of northern Greek patients, presence accounted for 79.1% and agenesis for 20.9%. No significant difference was found between the frequencies of third molar presence on the left and right sides in either the maxilla or mandible.

Keywords: third molars, presence, orthodontic population, Greeks