Non-surgical camouflage of severe skeletal Class II with protrusion and gummy smile using 3D planning, temporary anchorage device, and botulinum toxin: A case report
Year: 2025
Type: article
Study design: Case Report
Abstract: The study aimed to describe the interdisciplinary non-surgical management of a severe skeletal Class II division 1 malocclusion with bimaxillary protrusion and asymmetric gummy smile using three-dimensional (3D) digital planning, skeletal anchorage, and unilateral botulinum toxin injection. A 38-year-old female presented with lip incompetence, a 4 mm unilateral gummy smile on the right side, and protrusive upper and lower incisors. Cephalometric analysis showed A point, nasion, B point (ANB) 4.1°, U1-SN 125°, and incisor mandibular plane angle (IMPA) 105°. The treatment plan included the extraction of teeth 24, 35, and 45; full fixed appliance therapy; two maxillary inter-radicular miniscrews and two mandibular buccal shelf miniscrews for en masse anterior retraction and vertical control; and unilateral botulinum toxin injection at the Yonsei point after debonding to reduce hyperactivity of the right upper lip elevator complex. Total treatment time was 24 months. Post-treatment records demonstrated improved facial profile, symmetrical smile, and Class I canine and molar relationships. Cephalometric changes included a reduction of ANB from 4.1° to 2.8°, U1-SN from 125° to 108.9°, and IMPA from 105° to 95.2°. Gingival display on the right side was reduced from 4 mm to within normal limits, with balanced smile esthetics. The combination of digital 3D planning, skeletal anchorage mechanics, and targeted unilateral botulinum toxin injection can effectively address both the dental-skeletal and soft-tissue components of an asymmetric gummy smile in a severe skeletal Class II case. This approach offers a predictable, minimally invasive alternative to orthognathic surgery for selected adult patients.
Source: APOS Trends in Orthodontics
Author: Viet Hoang
Language: English
Subfield: Orthodontics
Field: Dentistry
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4415905325