Supernumerary teeth among Irish school children attending the public orthodontic service in Cork and Kerry.

Introduction Supernumerary teeth may be defined as extra teeth occurring within the dental arch. These teeth may be found within the deciduous dentition, but are more commonly found within the permanent dentition. The prevalence of supernumerary teeth in the permanent dentition has been investigated in several studies (Table 1); it varies from 0.45% to 4.5%. In Ireland the levels vary between 2.2% and 3.7%. Not only does the prevalence of supernumerary teeth vary among different ethnic populations, but the site and type of the supernumerary tooth also varies among different ethnic groups. It was decided, therefore, to re-examine data collected between January and June 1996 regarding supernumerary teeth in patients that presented to the orthodontic service in the counties of Cork and Kerry, i.e., the former Southern Health Board area. The population of Cork and Kerry in 1996 was 532,263. Material and methods The records of 100 consecutive patients who presented to the Southern Health Board orthodontic services, where the presence of a supernumerary tooth was identified, were examined. All patients were seen between January and June 1996, and all patients were Caucasian. Some patients had supernumerary teeth clinically visible, whereas in other cases they were found on radiographic examination. The age profile of the patients at referral was not considered. Some patients were recent referrals, whereas others had been on an orthodontic waiting list for a number of years. The resorbtion of the adjacent teeth to the supernumerary teeth was not considered as part of this study.