Dental Age Assessment: a comparison of 4- to 24-year-olds in the United Kingdom and an Australian population.

BACKGROUND: The physiological age of a person is determined by the degree of maturation of the different tissue systems. Children of the same chronological age (CA) can demonstrate different degrees of maturation. Dental age (DA) is based on the maturation of teeth. Tooth formation is a continuous process, where the developmental stages of the tooth can be sequenced and defined depending on the degree of mineralization. These stages can be visualized on a dental panoramic tomograph (DPT). AIM: The aim of this study was to use a new method of Dental Age Assessment (DAA) to compare a United Kingdom (UK) and an Australian (AUS) population. DESIGN: The DPTs used are from the archives of the Westmead Centre for Oral Health (Westmead, Australia) and the King's College London Dental Institute. From the preliminary sample of 89 DPTs from each population, 77 were suitable for use as matched pairs. The radiographic technique used was developed by Demirjian and describes eight stages of tooth development. This was used in combination with numerical data derived from a meta-analysis of a single UK subject. RESULTS: A significant difference was shown between the CA and DA of the AUS patients. The AUS patients were also shown to have a significant 0.82 years delay in their DA compared to the UK patients. The findings indicate a difference in AUS compared to UK patients. These results indicate the need to develop a reference data set for the AUS population for DAA. CONCLUSIONS: This research is of significance in a number of clinical disciplines and can also be used to assist in age determination of subjects of unknown birth date to assist in forensic dentistry or social deliberations.

Assessment of the "golden proportion" in agreeable smiles.

OBJECTIVES: The aim of this study was to determine the prevalence of the "golden proportion" in individuals presenting agreeable smiles. METHOD AND MATERIALS: Two hundred sixty university students aged 18 to 30 years of age (130 subjects of each gender) with maxillary incisors, canines, and premolars presenting anatomic integrity were evaluated. Agreeable smiles were considered to be those displaying at least second premolars; revealing no gingival recession in the smile area; having interdental papillae that filled all interdental spaces and were not hyperplastic; showing less than 3 mm of the maxillary gingiva; displaying the line of the lower lip parallel to the incisal line of the maxillary teeth and also to an imaginary line linking the contact points of these teeth; and, finally, presenting symmetry upon examination. Twenty-one individuals of this sample who presented this kind of smile (11 female and 10 male subjects) had their maxillary incisors, canines, and premolars of the same hemiarch measured in the cervicoincisal and mesiodistal directions using a periodontal probe, a digital Boley gauge, and digitalized analysis. Data were submitted to statistical analysis for comparison of adjacent teeth considering 1.618 (golden proportion) as a reference, with a statistical significance of P < .05. RESULTS: Of the agreeable smiles evaluated, 7.1% exhibited the golden proportion. CONCLUSION: The golden proportion was not often found in adjacent teeth shown in smiles in the sample studied.