Diagnosis and Building Your Care Team

Getting to a diagnosis of Hemifacial Hyperplasia (HFH) is often a journey of ruling out more common conditions. Because it is so rare, the process requires a combination of high-tech imaging, specialized genetic testing, and a team of experts who look at the “big picture” of your or your child’s health ^[1][2].

The Diagnostic Process

Diagnosis usually begins with a clinical exam, followed by detailed imaging to see exactly which tissues are involved:

• 3D Imaging: Tools like Computed Tomography (CT) or Cone Beam CT (CBCT) allow doctors to measure bone density and volume with extreme precision ^[3][4]. Stereophotogrammetry (a specialized 3D camera system) may be used to map the soft tissues of the face without radiation ^[3].
• Tissue Biopsy: This is the “gold standard” for confirming HFH ^[5]. Because the genetic change is mosaic (only in certain cells), a standard blood test will almost always come back negative ^[6][7]. Instead, doctors must test a small sample of the affected skin, fat, or bone using ultra-deep sequencing to find the mutation ^[6][8].

Note on Biopsy Logistics: The thought of a surgical biopsy on the face can be terrifying. To minimize scarring, surgeons often wait to collect this tissue during another necessary procedure (like a dental extraction or minor debulking), or they use a tiny “punch biopsy” in a hidden area. Talk to your surgeon about the least invasive way to get this sample.

Ruling Out “Mimics”

Several other conditions can cause facial asymmetry, and it is vital to distinguish them from HFH to ensure the right long-term care:

• Beckwith-Wiedemann Syndrome: This can cause overgrowth but often involves the tongue (macroglossia) and may affect internal organs, which HFH does not ^[4].
• Proteus Syndrome: This involves more aggressive, “distorting” overgrowth and often affects other parts of the body, like the hands or feet ^[4].
• Unilateral Condylar Hyperplasia (UCH): This is often confused with HFH, but UCH typically starts in late adolescence, whereas HFH is present at birth ^[1][9].

Building Your Care Team

Managing HFH requires a multidisciplinary approach—meaning doctors from different specialties must talk to each other ^[3][1]. Your core team should include:

1. Craniofacial / Maxillofacial Surgeon: The “architect” of the team who manages bone and soft tissue changes ^[10][11].
2. Orthodontist: A specialist with experience in craniofacial cases who can manage the unique dental and bite issues associated with uneven jaw growth ^[3][12].
3. Clinical Geneticist: To help confirm the diagnosis through proper testing and provide guidance on the PROS spectrum ^[9].
4. Speech-Language Pathologist (SLP) / Feeding Specialist: Critical for evaluating and managing speech articulation, feeding, and swallowing difficulties caused by jaw misalignment or soft tissue overgrowth in the airway.
5. Psychologist or Counselor: To provide emotional support for the unique social and self-esteem challenges of living with a facial difference.

Vetting Your Experts

When meeting a new doctor, remember that you are interviewing them as much as they are evaluating you. Don’t be afraid to ask how many cases of HFH or PROS they have personally managed. Specialized Craniofacial Centers (often found at major university hospitals) are typically the best choice, as they already have these specialists working together in one building ^[13].