Class - III malocclusion: Genetics or environment? A twins study.

Etiology of class-III malocclusion is generally believed to be genetic. A wide range of environmental factors have been suggested as contributing factors for the development of class-III malocclusion. Twin study is one of the most effective methods available for investigating genetically determined variables of malocclusion. Discordancy for class-III malocclusion is a frequent finding in dizygotic twins. However, class-III malocclusion discordancy in monozygotic twins is a rare finding. The purpose of this study of monozygotic twins is to assess the genetic and environmental components of variation within the cranio-dento-facial complex.

A mixture of Ca(OH)2 paste and ZnO powder as a root canal filling material for primary teeth: a preliminary study.

The present pilot study was conducted on five primary mandibular second molars requiring endodontic treatment to evaluate the clinical and radiographic success of root canal filling material which was a mixture of calcium hydroxide paste (1 cm), Zinc oxide powder (15 gms) and distilled water using hand operated lentulo spirals. All the five cases on clinical evaluation after 2,4,6,9, and 12 months were found to be asymptomatic with no history of pain, tenderness or abnormal mobility. Immediate post-operative radiographic evaluation revealed adequate root canal filling in all cases. The obturated material remained upto the apex of root canals till the beginning of physiologic root resorption. The roots of the primary teeth as well as the filling material mentioned above were seen to resorb at the same rate in one case.