AtlasDevelopmentalHemifacial Microsomia

Developmental Disorders

Hemifacial Microsomia

aka HFM · Craniofacial Microsomia · First and Second Branchial Arch Syndrome · Goldenhar Syndrome (with vertebral/ocular anomalies)

Second most common craniofacial anomaly; unilateral underdevelopment of mandible, ear, and soft tissues from first and second arch defects.

Prevalence
1:3,500–5,600
Classification
Pruzansky / OMENS
Key surgery
Distraction / costochondral graft

§ overviewOverview

Congenital asymmetric hypoplasia of structures derived from the first and second branchial arches, most commonly affecting the mandible, ear, and facial soft tissues.

§ icdICD Classification

Q87.0

§ etiologyEtiology

  • 01Sporadic vascular disruption of stapedial artery
  • 02Possible genetic component (14q32)
  • 03Environmental teratogens

§ epidemiologyEpidemiology

1:3,500 to 1:5,600 births. M:F = 3:2. Right side > left.

§ pathogenesisPathogenesis

Vascular disruption or haematoma in 1st/2nd arch territory → tissue necrosis → hypoplasia of mandible, ear, muscles of mastication.

§ clinicalClinical Features

  • 01Mandibular hypoplasia (Pruzansky grades)
  • 02Microtia/anotia
  • 03Facial nerve weakness
  • 04Soft tissue deficiency
  • 05Macrostomia
  • 06Preauricular tags
  • 07Vertebral anomalies (Goldenhar)

§ investigationsInvestigations

  • 01Clinical + 3D CT
  • 02Audiometry
  • 03Spine X-ray if Goldenhar suspected

§ classificationClassification

  • 01Pruzansky (I-III) — mandible
  • 02OMENS classification — comprehensive
  • 03Goldenhar = HFM + vertebral + epibulbar dermoids

§ treatmentTreatment

  • 01Multidisciplinary craniofacial team
  • 02Distraction osteogenesis (mandible)
  • 03Costochondral graft for TMJ reconstruction
  • 04Orthognathic surgery at skeletal maturity
  • 05Ear reconstruction

§ surgicalSurgical Management

  • 01Mandibular distraction
  • 02Costochondral rib graft
  • 03Microvascular free flap for soft tissue
  • 04Auricular reconstruction

§ complicationsComplications

  • 01Obstructive sleep apnoea
  • 02Malocclusion
  • 03Hearing loss

§ prognosisPrognosis

Good functional and aesthetic outcomes with staged surgical management.

§ examKey Examination Points

  • 01Pruzansky grading predicts surgical approach
  • 02Goldenhar = HFM + vertebral + eye anomalies
  • 03Distraction useful in growing child

§ revisionQuick Revision Summary

  • 011st + 2nd arch derivative hypoplasia
  • 02OMENS: Orbit, Mandible, Ear, Nerve, Soft tissue
  • 03Stapedial artery haemorrhage theory

§ vivaBDS Viva Questions

  • 01What is the Pruzansky classification?
  • 02Differentiate HFM from Goldenhar syndrome.
  • 03What is the role of distraction in HFM?

§ mcqsMCQs — Assessment (3)

Question 1

HFM results from defects in which branchial arches?

Question 2

Goldenhar syndrome includes HFM plus:

Question 3

Pruzansky Grade III mandible:

References

  1. Kaban LB. J Oral Maxillofac Surg 1998
  2. Neville BW. Oral & Maxillofacial Pathology, 4e

Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.