Association of Moderate-Severe Atopic Dermatitis with Dental Anomalies.

Atopic dermatitis is a common inflammatory skin condition with an underlying pathophysiology that may have impact beyond the skin. Previous studies showed a higher prevalence of dental cavities in patients with atopic dermatitis. Our study aimed to establish an association of other dental anomalies in patients with moderate-severe atopic dermatitis. We prospectively recruited 15 patients with moderate-severe atopic dermatitis for a formal dental examination by a paediatric dentist. Hypodontia and microdontia were more prevalent in patients with moderate-severe atopic dermatitis as compared to reference populations and were statistically significant. Dental caries, enamel hypoplasia and agenesis of 3rd molars were also prevalent but did not reach statistical significance. Our study shows a novel finding of higher prevalence of dental anomalies in patients with moderate-severe atopic dermatitis which may warrant further investigation due to its clinical implications.

Difference in Striae Periodicity of Heilongjiang and Singaporean Chinese Teeth.

Striae periodicity refers to the number of cross-striations between successive lines of Retzius in tooth enamel. A regular time dependency of striae periodicity, known as the circaseptan interval, has been proposed. Previous studies on striae periodicity have been carried out on both modern and early humans given its potential applications in forensic age estimations and anthropology. Nevertheless, research comparing striae periodicities across gender groups and populations in different geographical locations, particularly in Asia, is lacking. In this study, we compared the striae periodicities of Heilongjiang and Singaporean Chinese, as well as that of Singaporean Chinese males and females. Results showed that while the median striae periodicity counts of Heilongjiang Chinese and Singaporean Chinese teeth are both 7, Heilongjiang Chinese tend to have lower striae periodicity counts than Singaporean Chinese (p < 0.01). No significant gender difference was observed between the median striae periodicity of Singaporean Chinese Female and Singaporean Chinese Male teeth (p = 0.511). We concluded that the median striae periodicity may statistically differ with geographical location, but not gender, provided that ethnicity and geographical location are held constant. Further studies are required to examine the causes for variation in striae periodicities between geographical locations, as well as to verify the other bio-environmental determinants of striae periodicity.

High caries prevalence and risk factors among young preschool children in an urban community with water fluoridation.

BACKGROUND: Singapore is unique in that it is a 100% urban community with majority of the population living in a homogeneous physical environment. She, however, has diverse ethnicities and cultures as such; there may be caries risk factors that are unique to this population. AIM: The aims were to assess the oral health of preschool children and to identify the associated caries risk factors. DESIGN: An oral examination and a questionnaire were completed for each consenting child-parent pair. RESULTS: One hundred and ninety children (mean age: 36.3 ± 6.9 months) were recruited from six community medical clinics. Ninety-two children (48.4%) were caries active. The mean d123 t and d123 s scores were 2.2 ± 3.3 and 3.0 ± 5.6, respectively. Higher plaque scores were significantly (P < 0.0005) associated with all measures of decay (presence of decay, dt, ds). The risk factors for severity of decay (i.e., dt and ds) include child's age, breastfeeding duration, and parents' ability to withhold cariogenic snacks from their child. CONCLUSIONS: The high caries rate suggests that current preventive methods to reduce caries in Singapore may have reached their maximum effectiveness, and other risk factors such as child's race, and dietary and breastfeeding habits need to be addressed.

Epi-third and second harmonic generation microscopic imaging of abnormal enamel.

Enamel covers the tooth crown and is responsible for protecting the inner tissues of the teeth. It is thus clinically important to diagnose the anomalies in tooth enamel structures in the early stage for prevention and treatment. In this article, we report the epi-harmonic-generation-microscopic study of various abnormal enamel from the nature surface of human teeth. With a 1230 nm light source and with an epi-collection scheme, an imaging depth greater than 300 microm can be achieved. The contrast sources of THG and SHG in the abnormal enamel have been identified and verified by comparing the images from the sound enamel with those from white spot lesions, cracks, and the irradiated enamel. Besides the previously reported interprismatic space, THG is found to be contributed from cracks or the material inhomogeneities inside the enamel prisms; while SHG is attributed to the strain-induced breakage of the 6/m point group symmetry. Combined with the high 3D spatial resolution and no energy release during imaging, our study shows that the infrared-laser-based epi-harmonic generation microscopy can provide different contrasts to differentiate the abnormal enamel from sound enamel and could provide a valuable tool for in vivo monitoring of both morphological changes and strain status of hydroxyapatite crystals in the enamel without sectioning and staining.

Effect of Er:YAG laser and organic matrix on porosity changes in human enamel.

OBJECTIVES: Cariostatic effects of lasers have been well documented in the past few decades; however, the mechanisms remain unclear. Our previous study revealed the statistically significant effect of organic matrix (OM) in the laser-induced caries prevention. The aim of the present study is to further investigate the role of organic matters in the laser-induced porosity changes. METHODS: Enamel powder from five sound molars was randomly divided into two samples. One sample was treated with approximately 10% NaClO solution to remove OM and the other was left untreated. Both groups were then subjected to irradiation by an Er:YAG laser. The samples were characterized by thermogravimetric analysis (TGA) and N(2) physico-adsorption. RESULTS: TGA results confirmed that the NaClO treatment had at least partially removed the OM in enamel powder. The surface area and pore volume of normal enamel powder decreased significantly after laser treatment. In contrast, in the NaClO-treated enamel powder, laser treatment did not significantly decrease the surface area and the pore volume remained almost unchanged. The substantial difference between the normal enamel powder and the NaClO-treated enamel powder after laser treatment confirmed the laser-induced blocking of OM in the micro-diffusion pathway in enamel. CONCLUSION: The findings in this study seemed to substantiate the "organic blocking theory" as one of the mechanisms in the laser-induced caries prevention.

Bilateral talon cusps in primary teeth: clinical significance and treatment.

Bilateral primary talon cusps are uncommon. This case report documents two new cases of bilateral talon cusps in the primary dentition. The clinical features, radiographic characteristics, and differential diagnosis of this developmental anomaly are described. The terminology, epidemiological data, potential complications, and various modes of treatment are reviewed and discussed. A new classification system was proposed. The dental anomalies of these two cases were not associated with any other somatic or dental abnormality. The general prognosis of this abnormality is satisfactorily good. However, the dentist needs to have early recognition of this anomaly in order to provide timely treatment in order to prevent potential complications.