A study of cephalometric appraisal of the inheritance of craniofacial pattern in Gorkhas.

The phenotypic expression of biologic variability expressed in the craniofacial complex is influenced by constant interplay of heredity and environmental factors. The aim of this study was to observe the pattern of inheritance of cranio-facial complex in Gorkhas. Gorkhas are the original inhabitants of NEPAL in the slopes of HIMALAYAS and they generally marry strictly in their race. 76 individuals from 19 Gorkha families (son, daughter and both parents); were selected. Eight angular (saddle angle, articular angle, gonial angle, N-S-Gn, N-S-Go, SNA, SNB and ANB angles) and four linear (anterior facial height, posterior facial height, overjet and overbite) variables were measured from lateral head cephalograms and the values of the variables were evaluated and compared. It was found that the Inheritance of cranio facial pattern has shown significant coefficient of correlation from mother to offsprings for jarabak ratio, father to son for NS-Gn and NS-Go angle, father to daughter for articular and ANB angles. Different parts of craniofacial complex represents the resultant of morphology and size variation. Each one of these components are in turn influenced by many genetic and environmental factors.

Comparative evaluation of shear bond strength of different bracket base designs in dry and wet environments.

One hundred and thirty five extracted premolars were selected and bonded with three types of brackets with different bracket base designs viz. Gemini (foil mesh), Miniature twin (Laser etched) and Mini Dynalocks (Integral base). These brackets were bonded with Transbond XT adhesive using two types of primers viz. Conventional Transbond XT in dry conditions and M.I.P in dry and wet environments. The specimens were tested for SBS using Instron machine at C.I.P.E.T. (Amritsar), Punjab. Results were statistically analyzed. RESULTS AND DISCUSSION: The Miniature twin brackets revealed higher SBS values as compared to Gemini and Mini Dynalock in dry and wet conditions. All the groups showed higher SBS values in dry conditions as compared to wet conditions respectively. The Gemini and Mini Dynalock brackets showed very little difference of SBS values. CONCLUSION: Miniature twin brackets with laser etched bracket base in dry and wet environments have revealed the highest SBS values. All the groups have revealed clinically acceptable SBS value of above 8 MPa in moist conditions.