Trauma
Zygomatic Complex Fracture
aka ZMC Fracture · Tripod Fracture · Quadripod Fracture
Fracture of the zygoma at its four articulations (frontal, temporal, maxillary, sphenoid) producing malar flattening, diplopia, infraorbital paraesthesia and trismus.
§ figuresFigures (1)
Fig. 1CT brain bone window showing right zygomatic arch and anterior wall of right maxillary sinus fracture. Haemosinus is seen within the right maxillary sinus.
“CT brain bone window showing right zygomatic arch and anterior wall of right maxillary sinus fracture” · Cerevisae · CC BY-SA 4.0 · Wikimedia Commons
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Zygomatic Complex Fracture figures pending faculty review.
§ overviewOverview
Fracture of the zygomatic bone involving disruption at its articulations with the frontal, temporal, maxillary, and sphenoid bones (hence 'quadripod' rather than 'tripod').
§ etiologyEtiology
- 01Assault, RTA, sports (esp cricket/hockey)
§ clinicalClinical Features
- 01Flattening of malar prominence (masked by early oedema)
- 02Periorbital ecchymosis, subconjunctival haemorrhage extending posteriorly
- 03Infraorbital paraesthesia (V2)
- 04Diplopia, enophthalmos, hypoglobus
- 05Trismus (impingement on coronoid)
- 06Step deformity at infraorbital rim, zygomatic buttress, frontozygomatic suture
§ investigationsInvestigations
- 01CT face with coronal and 3D reconstruction (gold standard)
- 02Ophthalmology assessment: visual acuity, pupils, motility, fundus
- 03Occipitomental views if CT unavailable
§ classificationClassification
- 01Knight & North (1961) — six groups based on displacement and rotation
- 02Zingg (1992) — A (isolated), B (complete tetrapod), C (comminuted)
§ treatmentTreatment
- 01Undisplaced/minimally displaced without functional deficit: conservative + soft diet 4–6 wk + avoid sleep on affected side
- 02Displaced: open reduction with internal fixation via combined approaches: (1) frontozygomatic (upper eyelid or lateral brow), (2) infraorbital rim (subciliary/transconjunctival), (3) zygomaticomaxillary buttress (sublabial)
- 03Fix at 2–3 points depending on stability; Gillies temporal approach for pure arch fractures
- 04Orbital floor reconstruction if defect > 2 cm² or entrapment
§ complicationsComplications
- 01Persistent infraorbital paraesthesia
- 02Enophthalmos / diplopia
- 03Malar flattening
- 04Ectropion (subciliary approach)
- 05Sinusitis, malunion
§ prognosisPrognosis
Good with anatomical reduction; delayed treatment produces malunion requiring osteotomy.
§ examKey Examination Points
- 01Assess vision — retrobulbar haemorrhage is an emergency
- 02Palpate all four articulations
- 03Test V2 sensation
§ revisionQuick Revision Summary
- 01Quadripod fracture · CT gold standard · ORIF at 2–3 points · watch V2 and eye
§ vivaBDS Viva Questions
- 01Why is 'tetrapod' more accurate than 'tripod'?
- 02Approaches for ORIF?
- 03Indications for orbital floor reconstruction?
§ mcqsMCQs — Assessment (3)
Question 1
Zygoma articulates with all EXCEPT:
Question 2
Emergent complication requiring immediate decompression:
Question 3
Gillies approach is for:
§ evidenceReferences & Evidence
Current Classification
WHO Classification of Tumours Online — Head and Neck
IARC / WHO · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Evidence summary
Highest level of evidence linked to this page: WHO / Official Classification.
- L1 · Classification — 1
- L6 · Textbook — 5
1 linked source was published from 2024 onwards. Where guidance is limited or contested, rely on the higher-level sources above rather than this summary. Educational use only — not a substitute for clinical judgement.
Content last reviewed
September 2026
Evidence last reviewed
September 2026
Next scheduled review
September 2027
Review status
EVIDENCE REVIEWED
Search latest PubMed evidence
Last literature search: 7 September 2026
Current Classification
IARC / WHO. IARC · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Histopathology References
Barnes L. CRC Press · 2008
Detailed histopathological reference for head and neck diagnostic criteria.
Textbook References
Neville BW, Damm DD, Allen CM et al.. Elsevier · 2024
Standard reference textbook of oral and maxillofacial pathology used throughout this atlas.
Rajendran R, Sivapathasundharam B. Elsevier · 2020
Undergraduate and postgraduate oral pathology textbook widely used in BDS and FCPS curricula.
Hupp JR, Ellis E, Tucker MR. Elsevier · 2019
Core surgical textbook covering exodontia, infection, trauma and preprosthetic surgery.
Ehrenfeld M, Manson PN, Prein J. Thieme / AO Foundation · 2012
Reference standard for craniomaxillofacial trauma osteosynthesis principles and techniques.
Additional sources cited on this page
- Ellis E. Oral & Maxillofacial Trauma 4e
Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.