Abstract

Functional Genioplasty- Not Only a Mere Esthetic Benefit for Camouflage a Deficient Chin or Vertical Excess

by Chamberland Sylvain

Functional genioplasty (via inferior border osteotomy) as an isolated procedure allows simultaneous movements to correct both horizontal deficiency and vertical lower third excess. Excessive lower anterior face height, deficient anteroposterior (AP) chin position, and dentoalveolar protrusion may affect the neighbouring structure, including the lips, which often appear incompetent at repose. Bringing the lips into contact causes active contraction of the labiomental musculature, leading to the unesthetic soft-tissue contour of the chin and creating periosteal tension and muscular imbalance. In the past, surgery of the chin has been thought to be only a cosmetic procedure. However, changes in form also produce attendant changes in function. Thus, functional genioplasty changes facial convexity and helps achieve facial balance, can provide beneficial changes in lip function by altering the position and the form of the chin and its associated myocutaneous structures, improving labiomental muscular balance and lip competence and increase in chin-throat length. Patients who have excessive lower anterior facial height often have mandibular incisors display on smiling. Moving the chin upward or forward moves the lower lip up and decreases the display of the mandibular incisors on smiling. Thus, a genioplasty to improve facial balance influences the dynamic of smile display, allowing the lower lip to move up as the upper lip moves up. Improving the lip competence in repose and the smile display are 2 benefits of an inferior border osteotomy that explain the improvement in the function of the perioral musculature and hence the designation of functional genioplasty. Postsurgery osseous remodeling is unavoidable in genioplasty procedures. When the genial fragment is advanced with or without vertical reduction, bone remodeling occurs at the inferior border of the proximal segment between the distal point of the osteotomy cut and the advanced distal segment. When indications for this type of genioplasty are recognized, early surgical correction (before age 15) produces a better outcome in terms of bone remodeling.

Learning Objectives

After this lecture, you will be able to diagnose chin deficiency and vertical excess of the lower anterior face height.
After this lecture, you will be able to treatment plan the amount of surgical change
After this lecture, you will be able to understand the benefit of a functional genioplasty in terms of bone remodelling and lip function at rest.