Prader–Willi syndrome

Overview

Board takeaway: Use nonfood rewards and intensive saliva-aware prevention; assess obesity, hypotonia, and sleep-disordered breathing before sedation.

How does Prader–Willi syndrome affect dental management?

• Behavior: use nonfood reinforcers and coordinate with the family's food-security plan (locked kitchen, scheduled meals). Expect possible temper outbursts and oral self-injury.
• Prevention: address salivary symptoms, use fluoride toothpaste and varnish according to risk, and seal susceptible pits and fissures. Choose any prescription paste, rinse, or chewing product for the child’s age and ability to spit, chew, and swallow safely.
• Before sedation: review obesity, hypotonia, OSA/central apnea, diabetes, and the current sleep/respiratory assessment during growth hormone treatment.
• Setting and recovery: pediatric anesthesia determines the setting and postoperative monitoring from actual respiratory risk; significant sleep-disordered breathing may need hospital care.
• Infection: a high pain threshold and poor temperature regulation can mask symptoms; examine carefully.
• Medical review: check for diabetes.

Exam pearl

What is Prader–Willi syndrome?

An imprinting disorder caused by loss of expression of paternal genes in chromosome region 15q11-q13, with hypotonia, developmental differences, and later hyperphagia.

What are the main systemic features of Prader–Willi syndrome?

• Genetics: Loss of paternal 15q11-q13 expression: paternal deletion (~70%), maternal uniparental disomy, or imprinting defect
• Infancy: severe hypotonia, poor suck, failure to thrive
• Early childhood: hyperphagia, food seeking, obesity, type 2 diabetes
• Growth and endocrine: Short stature, small hands and feet, hypogonadism; growth hormone therapy
• Behavior and development: intellectual disability, temper outbursts, skin picking, high pain threshold
• Sleep: OSA and central apnea
• Comparison: Angelman syndrome involves loss of maternal expression in the same chromosome region.

What oral findings occur in Prader–Willi syndrome?

• Thick, sticky, scant saliva
• High caries risk, compounded by hyperphagia, food seeking, salivary changes, and enamel defects
• Severe tooth wear: attrition, erosion from rumination, and bruxism
• Enamel hypoplasia, delayed eruption, micrognathia
• Gingivitis and periodontal disease; self-injury of oral tissue

For Prader–Willi syndrome, why might infection be missed?

• High pain threshold can hide pain
• Poor temperature regulation can hide fever; examine carefully

Sources

• AAPD dental guidance: AAPD: Monitoring and management of pediatric sedation
• Supplemental systemic features: MedlinePlus Genetics: prader willi syndrome
• Supplemental study guide: Pediatric Dental Study Guide: Prader Willi Syndrome
• Management of Dental Patients with Special Health Care Needs
• Behavior Guidance for the Pediatric Dental Patient
• Pediatric Airway Assessment