Three-Dimensional Photography for Evaluating the Effectiveness of Botulinum Toxin Injection for Masseter Hypertrophy

Dun-Wei Huang; Chung-Yu Lai; Jia-En Chen; Chin-Chieh Yi; Ya-Hsin Chen; Chih-Hsin Wang; Shyi-Gen Chen

doi:10.1007/s00266-024-03974-7

Three-Dimensional Photography for Evaluating the Effectiveness of Botulinum Toxin Injection for Masseter Hypertrophy

Aesthetic Plast Surg. 2024 May 13. doi: 10.1007/s00266-024-03974-7. Online ahead of print.

Authors

Dun-Wei Huang^{1

2}, Chung-Yu Lai³, Jia-En Chen^{4

5}, Chin-Chieh Yi⁴, Ya-Hsin Chen¹, Chih-Hsin Wang¹, Shyi-Gen Chen⁶

Affiliations

¹ Division of Plastic and Reconstructive Surgery, Department of Surgery, National Defense Medical Center, Tri-Service General Hospital, No. 325, Sec. 2, Chenggong Rd., Neihu District, Taipei City, 11490, Taiwan, ROC.
² Department of Orthopedics, Hand and Arm Center, Harvard Medical School, Massachusetts General Hospital, Boston, USA.
³ National Defense Medical Center, Graduate Institute of Aerospace and Undersea Medicine, Taipei, Taiwan, ROC.
⁴ Medical 3D Printing Center, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan, ROC.
⁵ Department of Medical Physics and Bioengineering, University College London, London, WC1E 6BT, UK.
⁶ Division of Plastic and Reconstructive Surgery, Department of Surgery, National Defense Medical Center, Tri-Service General Hospital, No. 325, Sec. 2, Chenggong Rd., Neihu District, Taipei City, 11490, Taiwan, ROC. shyigen@gmail.com.

PMID: 38740625
DOI: 10.1007/s00266-024-03974-7

Abstract

Background: Masseter hypertrophy is a common condition that causes a undesirable square face, and often treated with botulinum toxin type A (BoNTA). Subjective assessments of BoNTA effectiveness vary from physician to patient, necessitating an objective approach for evaluation. This study introduces three-dimensional photography (3DP) for the first time in clinical assessment to evaluate BoNTA treatment for masseter hypertrophy.

Methods: Ten patients received 36U of BoNTA at three injection points on each side masseter muscle. 3DP scanner using Artec Eva® was taken at the first, third, and sixth postoperative months for objective evaluation. Patient's self-perceived prominence, patients self-rated satisfaction, and physicians provided 5-grade scores were the subjective indicators.

Results: A significant decrease in left masseter volume at the sixth month (P = 0.002, P = 0.004 at rest and clenching, respectively) was observed. Patient's self-perceived prominence decreased at the first (P = 0.021) and third (P = 0.039) months. Physicians' scores significantly decreased at all postoperative months. No significant changes were noted in the right masseter volume and patients self-rated satisfaction. Patient self-rated satisfaction did not consistently correlate with objective measures, except for left masseter with clenching at the sixth month.

Conclusion: Three-dimensional photography accurately quantifies facial changes post-BoNTA treatment. Despite objective improvements, patient satisfaction may not align consistently. Reliable assessment tools are crucial in cosmetic surgery to manage expectations and prevent disputes.

Level of evidence iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Keywords: Botulinum toxin type A (BoNTA) injection; Masseter hypertrophy; Objective evaluation; Patient satisfaction; Three-dimensional photography (3DP).