Overview
Primary condylar hyperplasia (PCH), also sometimes called mandibular condylar hyperplasia or condylar hyperplasia of the jaw, is a rare condition where one or both of the jaw joints (called condyles) grow too much or keep growing beyond the normal period of development. The condyle is the rounded end of the lower jawbone that connects to the skull. When this area grows abnormally, it causes the face and jaw to become uneven or asymmetrical over time. In some cases, both sides are affected, causing the lower jaw to grow too far forward. The most noticeable effects are changes in the appearance of the face, problems with how the upper and lower teeth fit together (called the bite or occlusion), and sometimes pain or difficulty chewing. The condition usually becomes apparent during the teenage years or early adulthood, when facial growth is still happening. It can progress slowly over several years before stabilizing. Treatment depends on whether the condition is still actively growing or has stopped. Options range from orthodontic braces to correct the bite, to surgical procedures to reshape the jaw or remove part of the overgrown condyle. With proper treatment, most people can achieve good facial symmetry and a functional bite. Early diagnosis is important to plan the right timing for any surgery.
Also known as:
Key symptoms:
Facial asymmetry — one side of the face looks different from the otherThe lower jaw shifts to one side or juts forwardTeeth do not fit together properly (malocclusion)Difficulty chewing foodJaw pain or discomfortProgressive changes in facial appearance over timeOpen bite — upper and lower front teeth do not meet when the mouth is closedCrossbite — lower teeth sit outside the upper teeth on one sideClicking or popping sounds in the jaw jointHeadaches related to jaw muscle strain
Clinical phenotype terms (6)— hover any for plain English
Sporadic
Usually appears on its own, not inherited from a parent
Juvenile
Begins in the teen years
Treatments
No FDA-approved treatments are currently listed for Primary condylar hyperplasia.
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Specialists
View all specialists →No specialists are currently listed for Primary condylar hyperplasia.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Primary condylar hyperplasia.
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Caregiver Resources
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Family & Caregiver Grants
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Social Security Disability
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Questions for your doctor
Bring these to your next appointment
- Q1.Is my condylar hyperplasia still actively growing, and how do you know?,What type of bone scan or imaging do I need, and how often should it be repeated?,At what point would you recommend surgery, and what type of surgery is best for my case?,Will I need braces before or after surgery, and for how long?,What happens if I choose not to have surgery?,Is there any chance the condition will come back after treatment?,Are there any support groups or resources for people with jaw asymmetry conditions?
Common questions about Primary condylar hyperplasia
What is Primary condylar hyperplasia?
Primary condylar hyperplasia (PCH), also sometimes called mandibular condylar hyperplasia or condylar hyperplasia of the jaw, is a rare condition where one or both of the jaw joints (called condyles) grow too much or keep growing beyond the normal period of development. The condyle is the rounded end of the lower jawbone that connects to the skull. When this area grows abnormally, it causes the face and jaw to become uneven or asymmetrical over time. In some cases, both sides are affected, causing the lower jaw to grow too far forward. The most noticeable effects are changes in the appearance
How is Primary condylar hyperplasia inherited?
Primary condylar hyperplasia follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Primary condylar hyperplasia typically begin?
Typical onset of Primary condylar hyperplasia is juvenile. Age of onset can vary across affected individuals.