Masseter Muscle Anti-Wrinkle - Contouring Injection Policy

Published:

November 4, 2025

1. Purpose

Provide a safe, evidence-based framework for using botulinum toxin type A (BoNT-A) in the masseter muscle for aesthetic contouring and functional management of hypertrophy, consistent with Australian clinical governance and current literature. ¹

2. Scope

Applies to AHPRA-registered practitioners administering or supervising anti-wrinkle injections to the masseter muscle for lower-face contouring or symptomatic relief of hypertrophy. ¹

3. Governance (Australia)

Requires a face-to-face consultation with a prescriber, compliance with TGA advertising and prescribing restrictions for Schedule 4 medicines, and documentation consistent with NSQHS medication-safety standards. ¹

4. Regional Anatomy & Injection Mapping

The masseter is a powerful chewing muscle at the mandibular angle. Injection mapping: identify muscle bulk via clench test, mark safe boundaries (upper limit: zygomatic arch; anterior: line from tragus to corner of mouth). Use multiple small aliquots across the muscle belly, avoiding risorius and parotid duct. ⁴

5. Dosing (Guideline Based)

Typical dose for aesthetic masseter reduction/hypertrophy: 20–50 U per side of BoNT-A (adjusted for anatomy, gender, muscle bulk, functional demands). Use distributed aliquots across the muscle belly. ⁵

6. Contraindications

Do not treat in pregnancy, breastfeeding, active infection at injection site, or significant neuromuscular disorders. Confirm full medical and allergy history before proceeding. ²

7. Informed Consent & Risks

Explain realistic outcomes (reduced masseter bulk, slimmer jawline), risks such as chewing weakness, asymmetry, or sunken cheeks from over-atrophy, and possible need for repeat injections every 4–12 months. ¹

8. Post-Treatment Care

Advise patient to avoid vigorous chewing, heavy biting, or dental clenching for first 24–48 hours; review at 2–4 weeks for symmetry and functional impact. ²

9. Adverse Events & Management

Possible mild pain or bruising at injection sites. Less common: reduction in bite strength, smile asymmetry, or sunken cheek appearance due to over-atrophy. Monitor chewing function and adjust future dosing accordingly. ⁶

10. Documentation & Audit

Record prescriber, injector, product name, lot, expiry, total dose per side, injection site map, consent, and pre/post photos. Conduct annual audit of outcomes and maintain 20 hours CPD in cosmetic injectables. ³

Sources

AHPRA 2025, Guidelines for Cosmetic Medical and Surgical Procedures, Canberra., viewed 04 November 2025, https://www.ahpra.gov.au/News/2025-09-02-New-guidelines-for-cosmetic-procedures.aspx ↩
Queensland Health 2024, Beginner’s Guide to Cosmetic Injectables, Brisbane., viewed 04 November 2025, https://www.health.qld.gov.au/newsroom/news/beginner-friendly-guide-to-cosmetic-injectables ↩
Australian Commission on Safety and Quality in Health Care (ACSQHC) 2023, NSQHS Standards – Medication Safety, Sydney., viewed 04 November 2025, https://www.safetyandquality.gov.au ↩
Kim J, Lee S, Kim JH et al. 2021, Simple Injection Technique for Masseter Reduction With Botulinum Toxin, Aesthetic Surgery Journal, 41(12): NP2104–NP2111., viewed 04 November 2025, https://academic.oup.com/asj/article/41/12/NP2104/6314953 ↩
Seo KK et al. 2024, Role of Botulinum Toxin in Masseter Muscle Hypertrophy, Toxins, 17(2):91., viewed 04 November 2025, https://www.mdpi.com/2072-6651/17/2/91 ↩
Wu Y, et al. (2023), Botulinum Toxin Type A for the Treatment of Masseter Muscle Hypertrophy: A Systematic Review and Meta-Analysis, Journal of Cosmetic Dermatology, 22(3), 567-576, viewed 04 November 2025, https://pubmed.ncbi.nlm.nih.gov/39998108/ ↩

Disclaimer for Newcastle Cosmetic Doctor Policies & Procedures

The policies and procedures contained within this document are the exclusive property of Newcastle Cosmetic Doctor and are provided for internal clinical governance and educational purposes only. These materials represent the internal operational framework, safety standards, and evidence-based protocols developed and implemented by Dr. Bart John Scanlon and the Newcastle Cosmetic Doctor team. They are designed specifically for use within Newcastle Cosmetic Doctor and reflect our clinic’s own professional standards, risk assessments, and compliance obligations under Australian law and regulatory authorities. External individuals, practitioners, or organisations must not copy, reproduce, distribute, or rely upon these materials, in whole or in part, for their own clinical, commercial, or educational use without prior written consent from Newcastle Cosmetic Doctor. These materials do not constitute medical, legal, or professional advice and are not intended to be adopted as official protocols or procedures by any other entity. Any external use or adaptation must be independently reviewed and modified to meet the relevant laws, guidelines, and standards applicable to the user’s own jurisdiction, scope of practice, and facility operations. Newcastle Cosmetic Doctor and Dr. Bart Scanlon accept no liability for any loss, injury, or damage arising from the unauthorised use, reliance upon, or misinterpretation of this material.