Skip to content
knowrare
HealthSignal
Your condition community

Living with Mandibular prognathia

A condition in which the lower jaw sits forward of the upper jaw, affecting how the teeth meet.

Understanding Mandibular prognathia

Mandibular prognathia is a jaw difference in which the lower jaw sits further forward than the upper jaw.

It shows up as a bite problem (malocclusion) where the first permanent molars meet in a forward position. It is present from birth.

Signs & symptoms

Symptoms vary from person to person. GARD lists these among the most common:

  • Large or forward lower jaw
  • Lower lip that droops or turns out
  • Open bite

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include genetic specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

Care & treatment

Care team
Genetic specialists (geneticists)
Expert care
Ask about multidisciplinary care centers for rare conditions
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with rare disease patient organizations for support
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Which specialist, such as an orthodontist or oral surgeon, should treat the jaw?
How will the bite change as growth continues?
Could this run in our family?

Quick facts

Symptoms usually startNewborn
InheritanceAutosomal Dominant

Changes in genes (also called variants) cause this condition. It is inherited in an autosomal dominant way, so a change in one copy of the gene can be enough.

Genetic

Also known as: anterior occlusion; anteroclusion; autosomal dominant prognathism; big lower jaw; big mandible; bulldog jaw

Patient organizations

Rare-disease groups that can help

Source: NIH GARD · Mandibular prognathiaGARD ID 10319 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Mandibular prognathia.

Explore the Mandibular prognathia blog

Explore research for Mandibular prognathia

Explore actively recruiting Mandibular prognathia studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Mandibular prognathia with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

Powered by HealthSpark, our AI chat helper

I can help you find recruiting Mandibular prognathia studies. Enter a ZIP code, address or city below and I'll look within 50 miles.

Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

Get Signals for Mandibular prognathia

Stay in the loop with community stories and updates from medical researchers.

HealthStoryfor Mandibular prognathia

Create a living journal that talks back

HealthStory evolves private journaling with a living AI journal that talks back and asks thoughtful questions, helping you capture your Mandibular prognathia experiences more deeply and prepare for better conversations with your doctors and care team.

Start your journal

Your journal is private. Sharing your story publicly is a separate choice, made with Share your story above.