Dental anomalies: Prevalence and associations between them in a large sample of non-orthodontic

Background: To analyze the prevalence and associations between dental anomalies detectable on panoramicradiographs in a sample of non-orthodontic growing subjects.Methods: For this cross-sectional study, digital panoramic radiographs of 5005 subjects were initially screened froma single radiographic center in Rome. Inclusion criteria were: subjects who were aged 8–12 years, Caucasian, andhad good diagnostic quality radiographs. Syndromic subjects, those with craniofacial malformation, or orthodonticpatients were excluded and this led to a sample of 4706 subjects [mean (SD) age = 9.6 (1.2) years, 2366 males and2340 females]. Sample was subsequently divided into four subgroups (8, 9, 10, and 11–12 year-old groups). Twooperators examined panoramic radiographs to observe the presence of common dental anomalies. The prevalenceand associations between dental anomalies were also investigated.Results: The overall prevalence of dental anomalies was 20.9%. Approximately, 17.9% showed only one anomaly, 2.7% two anomalies, while only 0.3% had more than two anomalies. The most frequent anomalies were the displacementof maxillary canine (7.5%), hypodontia (7.1%), impacted teeth (3.9%), tooth ankylosis (2.8%), and tooth transposition (1.4%).The lower right second premolar was the most frequent missing teeth; 3.7% had only one tooth agenesis, and 0.08% hadsix or more missing tooth (Oligodontia). Mesiodens was the most common type of supernumerary tooth (0.66%). Twosubjects had taurodontic tooth (0.04%). Tooth transpositions and displacement of maxillary canine were seen in 1.4 and 7.5%, retrospectively (approximately 69 and 58% were in the 8 and 9 year-old groups, retrospectively). Significantassociations were detected between the different dental anomalies (P < .05).Conclusions: The results of our study revealed significant associations among different dental anomalies andprovide further evidences to support common etiological factors.