Lip Repositioning With or Without Myotomy Treating Excessive Gingival Display

Objectives: The study aims to compare two surgical techniques for lip repositioning in subjects with excessive gingival display (gummy smile).
The objectives include 1) To compare the amount of gingival display reduction with myotomy and lip repositioning without myotomy, stratified in accordance with the etiology of the excessive gingival display. 2) To compare subject satisfaction and morbidity (swelling and pain) between the two techniques.
Methods: 20 human subjects with excessive gingival display (defined as 2mm or more of gingival display apical to the CEJ of #9) were randomly assigned to receive a lip repositioning procedure with or without a myotomy to treat the patient's excessive gingival display (Group 1 and Group 2 respectively). Pre-operative, diagnostic information (CEJ detectability, lateral cephalometric X-ray, lip mobility) was collected to determine the patient's etiology for excessive gingival display. Also, pre and post-operative measurements (gingival display, lip length, and vermillion border length) were taken with a digital caliper to record changes in the patients' gingival display and overall smile esthetics. Patients were followed up, 6 months after the surgical procedure.
Results: Combining both procedures, the average reduction in gingival display following lip repositioning was 3.5 mm. Lip repositioning with myotomy, on average, reduced gingival display by 4.2 mm, while without myotomy the average reduction was 3.25 mm. The differences between these two procedures were statistically significant for patients with excessive gingival display caused by vertical maxillary excess (VME), VME and altered passive eruption (APE), or a hypermobile lip.
There were no statistically significant differences in patient satisfaction nor patient morbidity between the two surgical procedures.
Conclusions: Lip repositioning with and without myotomy are valid treatment options for treating patients with excessive gingival display. Our study suggests that if a patient has VME, VME and APE, or a hypermobile lip, a myotomy should be performed to deter relapse of the excessive gingival display.