Gardner syndrome

Overview

Board takeaway: Refer multiple jaw osteomas with dental anomalies for genetics and gastroenterology assessment; plan dental surgery from symptoms, obstruction, and anatomy.

An autosomal dominant condition caused by an APC mutation. Jaw osteomas and dental anomalies often appear years before intestinal polyps. Without colectomy, colorectal cancer is nearly inevitable in classic familial adenomatous polyposis.

How does Gardner syndrome affect dental management?

• Referral: Refer for genetic counseling and gastroenterology
• Surgery: Surgical removal of impacted teeth and odontomas as indicated
• Treatment selection: Plan treatment of dental anomalies with orthodontics and oral surgery according to symptoms, obstruction, and anatomic findings; an asymptomatic osteoma does not automatically need removal

Exam pearl

What is Gardner syndrome?

A variant of familial adenomatous polyposis, usually caused by an autosomal dominant APC mutation, with numerous colorectal polyps and extracolonic findings such as osteomas, skin cysts, and dental abnormalities.

What are the main systemic features of Gardner syndrome?

• Genetics: APC tumor suppressor mutation on chromosome 5q; about one third are new mutations
• Cancer risk: Colorectal polyps commonly develop in adolescence; the lifetime colorectal cancer risk approaches 100% without colectomy in classic FAP. GeneReviews.
• Other findings: Epidermoid cysts, desmoid tumors, congenital hypertrophy of the retinal pigment epithelium, thyroid cancer

What oral findings occur in Gardner syndrome?

• Osteomas: Multiple osteomas of the mandible, especially the angle, and skull and sinuses
• Dental anomalies: Compound odontomas, supernumerary teeth, impacted or unerupted teeth, hypercementosis
• Cysts: Dentigerous cysts

For Gardner syndrome, why are osteomas, odontomas, and impacted supernumeraries urgent?

• Suspect Gardner syndrome/APC-related familial adenomatous polyposis with multiple mandibular osteomas, odontomas, and impacted or supernumerary teeth. Dental findings may precede intestinal polyps.
• Colorectal cancer risk approaches 100% without colectomy in classic FAP; polyps commonly begin in adolescence.
• Genetics/GI referral for counseling and colonoscopy can be lifesaving

How is Gardner syndrome inherited?

• Inheritance: Autosomal dominant APC-related disease; absence of a family history does not exclude a new variant.
• Family assessment: Refer for genetic counseling, testing, and appropriate evaluation of first-degree relatives rather than diagnosing relatives from dental findings alone.

Sources

• Supplemental study guide: Pediatric Dental Study Guide: Gardner Syndrome
• Management Considerations for Pediatric Oral Pathology
• Supplemental genetics: MedlinePlus Genetics: familial adenomatous polyposis
• AAPD best practice: AAPD: Management of Dental Patients with Special Health Care Needs (2026)