Wisdom Tooth Formation as a Method of Estimating Age in a New Zealand Population

Abstract

Dental ageing relies on assumptions aboutthe progression of tooth development from the middletrimester to adulthood and relative stability of thisprocess in the face of adverse dietary, hormonal, diseaseor nutritional factors. Most studies of dental ageingemploy the method of Demirjian et al., (1973), which isbased upon an assessment of crown and root formationstages from dental radiographs. Unfortunately, thismethod has a ceiling effect at age 16, when the secondmolar attains full maturity. The aim of our study was toextend the window of ageing by using the developmentof the third molar teeth. Panoramic radiographs of 207(105 males) children aged between 7 years, 6 months and18 years formed the basis of this study. Upper and lowerleft wisdom teeth were scored according to Demirjian et al. (1973) by a single examiner. Intra-examiner reliabilitywas evaluated by repeat scoring of a randomly selected(10%) sample one week after the initial staging. Theseshowed a consistency of 76% for the mandibular data and95% for the maxillary data, giving an overall percentageof 85%. When the re-scored teeth were not consistentwith their original score, this differed only by one stage.In this population males were advanced in their thirdmolar development and this trend was more markedfor maxillary than mandibular wisdom teeth. Hence, theNew Zealand population examined, males were moreadvanced in their third molar development and thistrend was more marked for maxillary than mandibularteeth.