Spearman correlation assessment of dermal collagen and elastic fibers in skin tissues of two different orientations from head and neck region

Back ground: The differences in quantitative fraction of dermal collagen and elastic fibers in two orientations of skin tissues from head and neck region have been explained under its varied skin texture and skin lines. Further detailed investigation in the pattern of correlation of collagen content between horizontal (CH) and vertical (CV) directions as well as that of elastic fiber content between horizontal (EH) and vertical (EV) directions has been undertaken in this study. Materials and method: Total of 320 skin samples were collected in horizontal and vertical orientations from temporal, submandibular, neck, lateral canthal and forehead areas of 32 human cadavers and processed histologically. Spearman correlation coefficient (r) was calculated from the quantitative fraction data of dermal collagen and elastic fiber content to investigate the linear association between the variables (CH/CV/EH/EV) statistically. Strength of association between the variables of significant correlation (p<0.05) were evaluated. Results: Statistically significant positive correlation between CH and CV in all 5 areas, between EH and EV in all areas except in forehead were noted. Negative correlation between CV and EV was found in temporal, submandibular and neck regions. But none of these areas showed correlation between CH and EH. Conclusion: Positive correlation for collagen and elastic fibers between horizontal and vertical directions, and negative correlation of these fiber contents in vertical direction in the selective areas provide valuable guidelines to aesthetic surgeons in placing elective incisions in the direction which maximally utilizes the anatomical facts for aesthetically pleasing result.