Hypo-hyperdontia in an Irish population

The records of 3,056 orthodontic patients, for whom adequate orthopantomogram radiographs were available, were examined to assess the prevalence of hypo-hyperdontia. The level of 0.45% was in line with previous studies. However, only 131 patients were eligible to be assessed for congenital absence of third molars. It may be that if a more mature sample were examined, the actual prevalence might be higher than the quoted figure.