Purpose

Provide a defensible, anatomy-led protocol for safe HA cheek augmentation aligned with Australian regulation and international safety frameworks.

1. Scope & Indications

Applies to hyaluronic acid (HA) fillers for midface volume restoration, malar projection, and contour harmonisation in adults following a medical consultation and informed consent. Indications include age-related midface deflation, zygomatic hypoplasia, and contour asymmetry. Contraindications include active infection, pregnancy/breastfeeding, uncontrolled systemic disease, or unrealistic expectations; psychological screening is advised. Documentation must reflect indication, alternatives, risks, costs, and cooling-off consistent with Australian standards. ^{1 2 3}

2. Midface Anatomy & Vascular Considerations

The cheek is composed of layered superficial and deep fat compartments overlying zygomatic and maxillary skeleton. Clinically critical structures include the infraorbital foramen (nerve/artery) below the orbital rim, angular/facial arterial system medially, and zygomaticofacial vessels laterally. Understanding the transition between deep and superficial fat compartments informs safe planes and expected filler spread. Anastomoses with the ophthalmic system create a theoretical pathway for ocular events in the case of intravascular injection. ^{4 5 6 7 8}

3. Product Science — HA Rheology & Selection

For lateral malar projection on bone, prioritise HA with higher elastic modulus (G′) and cohesivity to resist deformation; for medial cheek blend/tear-trough junction support, consider mid‑range G′ with balanced viscosity to minimise Tyndall and irregularities. Crosslinking density and HA concentration influence lift, spread, and longevity; higher cohesivity improves shape retention but may feel firmer in thin skin. Select rheology based on target plane, skin thickness, and dynamic forces; avoid overcorrection to reduce migration and oedema risk. ^{9 11 10}

4. Pre‑Treatment Preparation

Complete a medical history (anticoagulants, autoimmune disease, previous fillers/threads), photography in standard views, and informed consent outlining material risks including vascular occlusion and vision risk. Mark the infraorbital foramen and danger triangles; plan vectors for lift versus medial support. Apply antisepsis per NHMRC guidance; consider topical or local anaesthesia where appropriate. Ensure immediate availability of hyaluronidase, anaphylaxis kit, and a documented escalation pathway. ^{1 2 11 12}

5. Injection Techniques (Planes & Access)

Lateral Zygomatic Projection (on bone): Using a 25—27G needle or 22—25G cannula, access via lateral entry. Place small supraperiosteal boluses (e.g., 0.1—0.3 mL) at the zygomatic eminence and arch to restore ogee curve. Aspirate where feasible, inject slowly (≤0.1 mL/s), and assess perfusion between boluses. ^{7 8 9 17}

Medial Malar Support (deep fat plane): Using a 25G cannula via lateral entry, traverse to the deep medial cheek fat. Deposit micro‑aliquots while avoiding the infraorbital foramen. Maintain low pressure and continuous cannula motion to minimise arterial puncture; avoid peri‑foraminal boluses. ^{8 16 17}

Tear‑Trough Interface (cautionary note): Where transition support is required, favour conservative volumes with mid‑range G′ placed on bone (very small aliquots) or deep plane via cannula, avoiding superficial placement to reduce Tyndall. Consider staged treatments with re‑assessment after two weeks. ^{9 10 16}

6. Dosing Strategy & Pearls

Start low, build gradually: typical initial total volumes 0.5—1.5 mL per side depending on deficiency and skin thickness. Employ vector‑based placement (lateral scaffold first) before medial blending. Prefer fewer, well‑placed deep boluses over multiple superficial deposits to reduce nodularity and vascular risk. Schedule a review at 2—4 weeks for symmetry and functional assessment before any top‑up. ^{10 11 17}

7. Intra‑Procedure Safety & Red Flags

Continuously monitor capillary refill, patient‑reported pain, colour change, and temperature. Red flags: sudden severe pain, blanching, livedo, coolness, or visual disturbance. Stop immediately, massage, apply warmth, consider hyaluronidase according to dose maps, and activate ophthalmic pathway if visual symptoms occur. Record events in real time. ^{13 14 5 6 15}

8. Complications — Immediate & Delayed

Immediate: vascular compromise, haematoma, vasovagal episodes. Delayed: oedema, malar mounds, Tyndall, nodules/biofilm, and migration. Management includes protocol‑guided hyaluronidase for HA, compression/ice for haematoma, delayed reassessment for oedema, and antimicrobial/anti‑inflammatory strategies for suspected biofilm in line with authoritative guidance. Serious events should be considered for TGA reporting (DAEN). ^{3 4 11 18}

9. Documentation, Privacy & Advertising Compliance

Record indication, product, batch/lot, expiry, total dose, planes, vectors, and post‑care advice. Store clinical images securely and obtain separate consent for any educational/marketing use. Ensure public claims avoid testimonials and comply with AHPRA/TGA guidance; present risks and variability transparently. Align records and communication practices with APPs and NSQHS governance. ^{1 2 16 17 14}

10. Follow‑Up & Continuous Improvement

Review at 2—4 weeks for symmetry, function, and satisfaction; document PROMs where feasible. Audit adverse events, refrigeration logs (if applicable), batch traceability, and escalation timings. Run periodic simulations for vascular occlusion and anaphylaxis; incorporate lessons into protocols and education. Benchmark practice against WHO patient‑safety objectives and local standards. ^{2 5 11 18}

Sources

1. AHPRA/Medical Board of Australia, Guidelines for cosmetic medical and surgical procedures (2025), viewed 28 October 2025, https://www.medicalboard.gov.au/ ↩
2. Australian Commission on Safety and Quality in Health Care (ACSQHC), National Safety and Quality Health Service (NSQHS) Standards, viewed 28 October 2025, https://www.safetyandquality.gov.au/standards/nsqhs-standards ↩
3. Therapeutic Goods Administration (TGA), Reporting adverse events and problems (DAEN), viewed 28 October 2025, https://www.tga.gov.au/safety/database-adverse-event-notifications-daen ↩
4. ACE Group World, Aesthetic Complications Expert Group (Complications guidance), viewed 28 October 2025, https://uk.acegroup.online/ ↩
5. Australian and New Zealand Committee on Resuscitation (ANZCOR), Anaphylaxis and Basic Life Support (current guidelines), viewed 28 October 2025, https://www.anzcor.org/ ↩
6. Beleznay K, Carruthers JD, Humphrey S, Jones D (2015), Avoiding and Treating Blindness From Fillers: A Review of the World Literature, Dermatologic Surgery, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/26356847/ ↩
7. Cotofana S, Lachman N (2019), Arteries of the Face and Their Relevance for Minimally Invasive Facial Procedures: An Anatomical Review, Plastic and Reconstructive Surgery, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/30688884/ ↩
8. Mendelson B, Wong CH (2013), Surgical anatomy of the middle premasseter space and its application in sub-SMAS face lift surgery, Plastic and Reconstructive Surgery, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/23806908/ ↩
9. Rohrich RJ et al., The fat compartments of the face: anatomy and clinical implications for cosmetic surgery, Plastic and Reconstructive Surgery, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/17519724/ ↩
10. Pierre S, Liew S, Bernardin A (2015), Basics of dermal filler rheology, Dermatologic Surgery, 41(Suppl 1), S120–S126, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/25828036/ ↩
11. Rashid A, A Comprehensive Evaluation of Dermal Fillers in Aesthetic Medicine: Safety, Efficacy, and Long-Term Outcomes (2025), viewed 28 October 2025, https://doi.org/10.63096/medtigo3061224 ↩
12. Office of the Australian Information Commissioner (OAIC), Australian Privacy Principles (health information & clinical images), viewed 28 October 2025, https://www.oaic.gov.au/privacy/australian-privacy-principles ↩
13. AHPRA, Advertising a regulated health service (compliance resource), viewed 28 October 2025, https://www.ahpra.gov.au/Resources/Advertising-hub.aspx ↩
14. NHMRC, Australian Guidelines for the Prevention and Control of Infection in Healthcare, viewed 28 October 2025, https://www.nhmrc.gov.au/about-us/publications/australian-guidelines-prevention-and-control-infection-healthcare-2019 ↩
15. World Health Organization (WHO), Patient Safety: Global patient safety action plan, viewed 28 October 2025, https://www.who.int/teams/integrated-health-services/patient-safety ↩
16. Hufschmidt K, Bronsard N, Foissac R, Baqué P, Balaguer T, Chignon-Sicard B, Santini J, Camuzard O., The infraorbital artery: Clinical relevance in esthetic medicine and identification of danger zones of the midface (2019), viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/30327185/ ↩
17. Swift A, Remington K, BeautiPHIcation™: a global approach to facial beauty (2011), Clinical Plastic Surgery, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/21824535/ ↩
18. Funt D, Pavicic T (2013), Dermal fillers in aesthetics: an overview of adverse events and treatment approaches, Clinical, Cosmetic and Investigational Dermatology, 6, 295–316, viewed 28 October 2025, https://pubmed.ncbi.nlm.nih.gov/24363560/ ↩