Background: Pulp stones are discrete calcified bodies found in the dental pulp. The aims of this study were to calculate the prevalence of pulp stones in young Australian adults using radiographs, and to report any associations between occurrence of pulp stones and sex, tooth type, dental arch, side and dental status. Methods: From 217 undergraduate dental students, comprising 123 males and 94 females aged between 17-35 years, 3296 teeth were examined under 2x magnification on bitewing radiographs. Pulp stones were scored as present or absent, and associations with sex, tooth type, dental arch, side and dental status noted. Results: Pulp stones were found in 100 (46.1 per cent) of the subjects and 333 (10.1 per cent) of the teeth examined. Occurrences were rare in premolars (0.4 per cent) but significantly higher in molars (19.7 per cent). Pulp stones were significantly more common in first molars than in second molars, and in maxillary first molars than in mandibular first molars. Carious and/or restored maxillary right first molars and maxillary left second molars displayed higher prevalences of pulp stones than unrestored and intact molars. Conclusion: Pulp stones may provide useful forensic information when examining dental records to identify deceased persons.Key words: Pulp tissue, calcification, dental arches, dental status.(Accepted for publication October 2000.) and the latter being degenerative pulp calcifications. Other studies have noted problems with the above classification and new histologic classifications have been proposed. [2][3][4]

Non-carious cervical lesions involve loss of hard tissue and, in some instances, restorative material at the cervical third of the crown and subjacent root surface, through processes unrelated to caries. These non-carious processes may include abrasion, corrosion and possibly abfraction, acting alone or in combination. Abfraction is thought to take place when excessive cyclic, non-axial tooth loading leads to cusp flexure and stress concentration in the vulnerable cervical region of teeth. Such stress is then believed to directly or indirectly contribute to the loss of cervical tooth substance. This article critically reviews the literature for and against the concept of abfraction.Although there is theoretical evidence in support of abfraction, predominantly from finite element analysis studies, caution is advised when interpreting results of these studies because of their limitations. In fact, there is only a small amount of experimental evidence for abfraction. Clinical studies have shown associations between abfraction lesions, bruxism and occlusal factors, such as premature contacts and wear facets, but these investigations do not confirm causal relationships. Importantly, abfraction lesions have not been reported in pre-contemporary populations.It is important that oral health professionals understand that abfraction is still a theoretical concept, as it is not backed up by appropriate clinical evidence. It is recommended that destructive, irreversible treatments aimed at treating so-called abfraction lesions, such as occlusal adjustment, be avoided.

Symmetry is a major correlate of physical attractiveness across species, including humans. Investigating the nature of this relationship has been difficult, however, for several reasons, including the facts that variance in symmetry is attributable to more than one source and is often correlated with other variables related to attractiveness. This study assessed the role of facial symmetry in relation to perceptions of facial attractiveness. Some of the natural covariates of symmetry were controlled for by comparing the symmetry and attractiveness differentials between monozygotic co-twins, who are genetically, but not developmentally, identical. The more symmetric twin of a pair was consistently rated as more attractive, and the magnitude of the difference between twins in perceived attractiveness was directly related to the magnitude of the difference in symmetry.

The clinical importance of variations of tooth number, size and shape is seen in many dental disciplines. Early diagnosis allows optimal patient management and treatment planning, with intervention at an appropriate time to prevent complications in development and so reduce later treatment need. Understanding the process of dental morphogenesis and the variations in outcomes is an important contribution to the multidisciplinary clinical team approach to treatment. Tooth number, size and shape are determined during the initiation and morphogenetic stages of odontogenesis. The molecular evidence of repetitive signalling throughout initiation and morphogenesis is reflected clinically in the association of anomalies of number, size and shape. This association has been statistically modelled from epidemiological evidence and confirmed by 2D and 3D measurement of human dental study casts. In individuals with hypodontia, the teeth that are formed are smaller than the population mean and often show reduced and simplified shape. In contrast, in individuals with supernumerary teeth, the other teeth are larger than average and may show an enhanced shape. Clinical observations in humans and studies of laboratory animals gave rise to the concept of morphogenetic fields within the dentition. The findings, which can also be considered as reflecting gene expression territories, have been developed to incorporate field, clone and homeobox theories. The clinical distribution of developmental anomalies tends to follow the pattern of these fields or territories. Improved care for patients with these anomalies will come not only from utilizing a multidisciplinary clinical team but also by expanding the approach to include other relevant scientific disciplines.

No abstract