Esthetics is one of the major motivating factors for patients seeking orthodontic treatment. Hard tissue and soft tissue drape both determine the facial esthetics. The structures in this region are so variable that the nasolabial angle (NLA) has been drawn differently by various investigators. Variations can lead to erroneous conclusions in orthodontic diagnosis. Aims and objectives:The study was done to evaluate a reliable method of constructing the nasolabial angle (NLA) and to correlate the soft tissue profile parameters with one another. Materials and methods:Lateral cephalogram of 50 randomly selected adult patients were taken. The tracings were made and 10 copies of each tracing were randomly distributed to 10 different orthodontists to draw the NLA. Results:Pearson's correlation coefficient (r) showed both N/ FH and L/FH angles to have significant p values when compared with NLA. The regression analysis showed that the nasolabial angle can be calculated for any given value of N/FH or L/FH by the formula: NLA = 80.33° + 1.02° (N/FH) and NLA = 14.2° + 1.04° (L/FH). The mean value of N/FH was 17.42° ± 8.40° and L/FH was 80.68° + 6.45° for this sample. Inter examiner reliability calculated by repeated measures of ANOVA and Dahlerg's formula showed high degree of reliability and reproducibility of the method.Clinical significance: NLA can be predicted for any given value of N/FH and L/FH. NLA = 80.33° + 1.02° (N/FH) and NLA = 14.2° + 1.04° (L/FH). If an individual has either N/FH or L/FH in the normal range but not the NLA then one could calculate the correct NLA using this formula. Thereby the NLA can be brought within the normal range by altering the other nasolabial parameters by correct treatment planning. Since the nasolabial angle plays a vital role in profile esthetics of a person, the clinician should place greater emphasis in evaluating this area and plan treatment mechanics to place this angle within the accepted normal variation.

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Copper exhibits high thermal conductivity properties and hence it is extensively used in cryogenic applications like cold fingers, heat exchangers, etc. During the realization of such components, copper undergoes various machining operations from the raw material stage to the final component. During these machining processes, stresses are induced within the metal resulting in internal stresses, strains and dislocations. These effects build up resistance paths for the heat carriers which transfer heat from one location to the other. This in turn, results in reduction of thermal conductivity of the conducting metal and as a result the developed component will not perform as per expectations. In the process of cryogenic treatment, the metal samples are exposed to cryogenic temperature for extended duration of time for 24 hours and later tempered. During this process, the internal stresses and strains are reduced with refinement of the atomic structure. These effects are expected to favourably improve thermal conductivity properties of the metal. In this experimental work, OFHC copper samples were cryotreated for 24 hours at 98 K and part of them were tempered at 423K for one hour. Significant enhancement of thermal conductivity values were observed after cryotreating and tempering the copper samples.

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Objectives:The aim was to evaluate the relationship of the K-primer variant of the transforming growth factor-alpha (TGF-α) gene and C677T variant of the methylenetetrahydrofolate reductase (MTHFR) gene with nonsyndromic cleft lip and palate (CL/P) in the Indian population.Setting and Sample Population:The study group consisted of DNA samples of 25 subjects with nonsyndromic CL with or without cleft palate and 25 unrelated controls, already existing in the Department of Orthodontics, D.A.P.M.R.V. Dental College, Bengaluru, Karnataka, India.Materials and Methods:The DNA samples were divided into two categories: Group A which included the 25 subjects with nonsyndromic CL/P; and Group B, which consisted of the 25 unrelated controls. The polymerase chain reaction (PCR) test was done for amplification of the region of interest from the DNA samples. Restriction digestion was then performed on the amplified product using the restriction enzyme HinfI, separately for each of the variants. The digested PCR products were separated into channels on a 1.5% agarose gel containing ethidium bromide in an electrophoretic chamber. A U.V. transilluminator was used to see the specific bands of base pairs of the digested PCR products.Results:In Group A, the TGF-α gene variant was present in 16 subjects (P = 0.001) and MTHFR gene variant was present in 8 subjects (P = 0.185). A combination of both gene variants were present in seven subjects, which was an interesting finding. In Group B, four subjects tested positive for the TGF-α and MTHFR gene variants.Conclusions:The TGF-α gene variant and a combination of TGF-α + MTHFR gene variants significantly contribute to the development of nonsyndromic CL/P and can be considered as genetic markers for Indian population. The MTHFR gene variant, though a minor risk factor, cannot be considered as a genetic marker.