Prevalence of dental anomalies in a sample of growing subjects: a retrospective study

BACKGROUND: dental anomalies are a group of disorders characterized by alterations in tooth number, shape, size, structure, development, and timing of eruption due to genetic and environmental factors. OBJECTIVES: to identify the prevalence of dental anomalies in a large sample of non-orthodontic subjects. DESIGN: a retrospective chart review was conducted based on digital panoramic radiographs by two examiners who assessed the presence of displacement of the maxillary canines (DMC), impacted teeth (IT), tooth agenesis (TA), supernumerary/supplementary teeth (ST), and tooth transpositions (TT). SETTING AND PARTICIPANTS: radiographs of subjects aged between 8 and 18 years were analysed. A chi2 test was employed to assess possible associations between the number and type of dental anomalies and patients' gender. When an association was present, a binary logistic regression was conducted to calculate the odds ratio between the variables. The significance level was set at p<0.05. RESULTS: a total of 1,124 subjects (25.7%) showed at least one dental anomaly. DMC (12.1%) and IT (12%) were the most frequent dental anomalies. The most represented impacted teeth were the upper canine (9.2%) and the upper central incisor (1.3%). TA was detected in 296 radiographs (6.8%), with 134 showing two or more TA. The prevalence of ST and TT in the total sample was 2.2% and 0.7%, respectively. Associations were found between ST and IT, between TA and DMC, and between TA and IT. CONCLUSIONS: the results obtained encourage the radiographic investigation of dental anomalies at an early stage