BACKGROUND: The elliptical excision is a common surgical procedure. The dermatologic literature predominantly describes an excisional geometry with a 3:1 length:width ratio and an apical angle of 30 degrees. OBJECTIVE: To analyze the elliptical excision by applying mathematical principles and define the apical angle and its relationship to the length:width ratio. METHODS: We examined numerous examples of elliptical excisions as presented in the dermatologic literature. We analyzed the geometry of the excisions and defined it mathematically. RESULTS: The apical angle of a 3:1 elliptical excision is not 30 degrees. The true apical angle varies from 37 degrees to 74 degrees depending on excisional geometry. CONCLUSION: The commonly presented apical angle of 30 degrees is incorrect and does not reflect the true apical angle of elliptical excisions.
BACKGROUND: The elliptical excision is a common surgical procedure. The dermatologic literature predominantly describes an excisional geometry with a 3:1 length:width ratio and an apical angle of 30 degrees. OBJECTIVE: To analyze the elliptical excision by applying mathematical principles and define the apical angle and its relationship to the length:width ratio. METHODS: We examined numerous examples of elliptical excisions as presented in the dermatologic literature. We analyzed the geometry of the excisions and defined it mathematically. RESULTS: The apical angle of a 3:1 elliptical excision is not 30 degrees. The true apical angle varies from 37 degrees to 74 degrees depending on excisional geometry. CONCLUSION: The commonly presented apical angle of 30 degrees is incorrect and does not reflect the true apical angle of elliptical excisions.
Authors: David Chopp; Vinay Rawlani; Marco Ellis; Sarah A Johnson; Donald W Buck; Seema Khan; Kevin Bethke; Nora Hansen; John Ys Kim Journal: Can J Plast Surg Date: 2011