Depressor Anguli Oris (DAO) Anti-Wrinkle Policy

Published:

November 4, 2025

1. Purpose

Provide a safe, evidence-based framework for using botulinum toxin type A (BoNT-A) in the depressor anguli oris (DAO) muscle to relax downturned mouth corners and improve lower-face posture, in line with Australian cosmetic-medicine governance and clinical literature. ¹

2. Scope

Applies to AHPRA-registered practitioners who assess, consent, inject, or supervise injections of BoNT-A into the DAO muscle for aesthetic correction of the downturned mouth corner. ¹

3. Governance (Australia)

Requires face-to-face consultation by a prescriber, compliance with TGA requirements for Schedule 4 medicines, and documentation aligned with NSQHS medication-safety standards. ¹

4. Regional Anatomy & Injection Mapping

The DAO originates from the mental tubercle and inserts into the modiolus, exerting a downward pull on the oral commissure. Injection mapping: identify the muscle via clench/frown test, mark lateral to the modiolus and 5–10 mm below the cheilion-mandibular line; use small aliquots. The 3D analysis showed soft-tissue depth at DAO point ~6.7 mm. ⁴

5. Dosing (Guideline Based)

Typical dosing: 2–4 Units per side, injected at 1–2 sites each side into the mid-belly of the DAO. Adjust per anatomy, symmetry and functional requirements. ⁵

6. Contraindications

Defer in pregnancy, breastfeeding, active infection at site, neuromuscular disorder or uncontrolled medication interactions; review full history before proceeding. ²

7. Informed Consent & Risks

Explain expected outcome (gentle elevation of mouth corners, improvement of downturned expression), possible risks such as smile asymmetry, lower-lip imbalance, difficulty with pursing/pouting, bruising, or needing repeat treatments every 3–4 months. ¹

8. Post-Treatment Care

Advise patient to stay upright ≥ 4 hours, avoid massaging the area, strenuous exercise or facial treatments for 24–48 hours; review at 2 weeks for symmetry and effect. ²

9. Adverse Events & Management

Over-diffusion may affect the depressor labii inferioris or risorius, causing smile asymmetry or compromised lip movement. Manage conservatively and adjust future dosing accordingly. ⁶

10. Documentation & Audit

Record prescriber, injector, product name, lot, expiry, dose per side, injection map, consent, baseline and follow-up images, and outcome notes. Conduct annual audits, log complications, and maintain over 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 ↩
Yi KH, Lee JH, Hu HW et al. 2023, Novel anatomical proposal for botulinum neurotoxin injection targeting depressor anguli oris for treating drooping mouth corner, Anatomy & Cell Biology, 56:161–165., viewed 04 November 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10319486/ ↩
Hwang K, Kim DJ, Song JY. 2023, Increasing Precision When Targeting the Depressor Anguli Oris, Aesthetic Surgery Journal, 44(9): NP661–NP666., viewed 04 November 2025, https://academic.oup.com/asj/article-abstract/44/9/NP661/7633282 ↩
Munoz-Lora VRM, Thiesen V, Loureiro D, Giro G, Alfertshofer M, Cotofana S, Germani M (2024), Understanding clinical meaningfulness when targeting the depressor anguli oris muscle (DAO) with neuromodulators: a clinical prospective interventional study, Journal of Neural Transmission, viewed 04 November 2025, https://pubmed.ncbi.nlm.nih.gov/39276240/ ↩

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.