Coronal or Sagittal Incisions: A Mathematical Approach to the Problem

Abstract

Introduction: The debate on using sagittal (parallel) or coronal (perpendicular) incisions is ongoing. However, it is our belief that coronal incisions reduce injury to the subdermal vasculature while allowing for higher graft density. In this article, we will use mathematics to support our stance that coronal incisions cause less injury to the recipient area. Objective: To mathematically prove why coronal incisions cause less trauma to the recipient area and to quantify the exact percentage of graft density increase. Method: The trigonometric theory was applied to find an equation that correlates the size of both sagittal and coronal incisions with the size of a square-end blade at any given angle. Results: Using sagittal incisions with a square-end blade directed at an acute angle results in a wound that is significantly greater in length than the size of the blade. However, using coronal incisions, the blade creates the same size wound independently of the entry angle. Conclusion: Coronal incisions minimize injury to the skin while maximizing graft density, potentially allowing for better results.