Dental arch characteristics among South Indian twins - A morphometric study

Genetic and environmental factors are essential in occlusal variations and malocclusion and have been of considerable interest to orthodontists. Studies on twin pairs are one of the most effective methods for investigating genetically determined occlusal variables. Many studies have focused on distances between first molars or between canines but malocclusions can also occur in other regions of the dental arch. Aim: To evaluate the characteristics of the dental arch between pairs of Monozygotic (MZ) and Dizygotic (DZ) twins from Southern India. Methods: A random sample of 51 twin pairs (12­18years old) participated in this study. The zygosity of twin pairs was recorded by facial appearance. The occlusion of the first permanent molars was recorded according to Angle's classification. Study models were prepared to assess dental arch characteristics (i.e., arch form, arch perimeter, arch length; intercanine, intermolar width, and teeth size discrepancy). The obtained data was statistically analyzed using SPSS software 19.0. The student's t-test (two-tailed, independent) and Chi-square test was used to determine the significance of studied parameters. Results: Angle's Class I molar relation was more commonly observed followed by the Class II molar relationship among twins. The measured dental arch dimensions did not show a statistically significant difference among twin pairs. The ovoid arch form was commonly observed among Monozygotic and Dizygotic Twins. There was a similarity among MZ and DZ twins in the anterior and overall Bolton's ratio. Conclusion: There were similar occurrences of measured parameters among twins, which showed genetic predominance in the expression of measured dental arch traits

Assessment of salivary total antioxidant levels and oral health status in children with Down syndrome.

UNLABELLED: Down syndrome (DS) is an autosomal chromosomal disorder caused by trisomy of all or a critical part of chromosome 21. Individuals with DS have high levels of oxidative stress throughout their lifespan. It has been suggested that levels of antioxidants could be altered in response to an infection or disease. AIM: To assess the total antioxidant capacity (TAC), nitric oxide (NO), and sialic acid (SA) of saliva in children with DS and its relation to their oral health status. MATERIALS AND METHODS: Thirty-four noninstitutionalized children in the age group of 7-12 years having DS formed the study group. The control group consisted of 34 normal, healthy children. The W.H.O. criteria were used for diagnosis and recording of dental caries. Oral hygiene status was assessed using the simplified oral hygiene index. Estimation of TAC, NO, and SA levels in saliva was done. Data obtained were subjected to statistical analysis. RESULTS: In comparison to normal children, DS children showed significantly lower TAC of saliva and significantly higher salivary SA levels. In both groups of children, dental caries was higher in primary dentition when compared to their permanent dentition.