Canine-premolar Transposition, Family Pedigree and Related Dental Anomalies

Abstract

Maxillary canine-premolar transposition is a rare and complicated dental anomaly that needs specialconsideration by the orthodontist. The aim of the present study was to investigate the clinical features ofmaxillary canine-premolar transposition and report the family pedigree to determine the mode of inheritance.A cross-sectional study was performed on 39 patients having maxillary canine-premolar transposition inwhich both clinical and radiographic examination were performed. Moreover, 112 family members wereclinically examined looking for canine transposition. Variables such as location, sex and the presence ofhypodontia and peg-shaped lateral incisors were investigated. The study found that unilateral transposition(89.7%) was more common than bilateral occurrence (10.2%) affecting the left side (64.1%) more than theright side (35.9%). Females were affected more than males (74.4% and 25.6% respectively). Congenitallymissing teeth were reported in 12.8% and lower second premolar was the most commonly missing tooth.Peg-shaped maxillary lateral incisor was reported in 7.7% of the sample. Family pedigree confirmed thepresence of a history of transposition or ectopically positioned canine in 15.3% of the sample suggestingan autosomal dominant inheritance of the trait. In conclusion this study suggested an association betweengenetic factors and maxillary canine-premolar transposition. Further studies are required using genetictesting to confirm the findings of the present study.