A retrospective pilot study of correlation of first maxillary premolar root trunk length with age and gender: a cone beam computed tomography study.

Background: Root trunk length (RTL) plays an important role in the diagnosis, prognosis and treatment of periodontitis. The aim of this retrospective pilot study was to evaluate the RTL of first maxillary premolar and to study the correlation with age and sex in this value.

Methods: The sample included 110 cone beam computed tomography (CBCT) images comprising 220 maxillaries first premolars from systemically healthy patients aged between 18 and 70 years. The tooth length (TL), root length (RL) and RTL were measured (dependent variables). Age and sex were considered as independent variables.

Results: No statistically significant correlation was found between the RTL and the TL. Longer RL and longer RTL were observed in younger patients than older subjects only in the left maxillary premolars. On the other hand, the sex of the patients had no effect on either of the dependent variables. The single rooted maxillary premolars were more frequent (relative to those with two roots) in woman and in elderly patients.

Conclusions: A correlation between the age and the RTL and RL has been found but only in left premolars. Sex seemed to have only a slight correlation on the frequency of single-rooted teeth of the right side of the mouth. Further studies should be addressed to clarify the significance of the asymmetries observed in the present study between the two sides of the mouth with the aim of deepening the knowledge and understanding of the different variables that could be correlated with the RTL.