(6) Down's syndrome

Question 1

What are the causes of Down’s syndrome?

Answer 1

Complete or partial trisomy of chromosome 21

Question 2

What is the risk of having a child with Down’s syndrome? What are tests for diagnosis?

Answer 2

• Linked to maternal age (nondisjunction of chromosomes)
  
  • Aged 30+ - 1 in 1000
  • Aged 40+ - 1 in 100
• Amniocentesis (high risk)
• Blood test

Question 3

What are medical conditions that need to be considered for patients with Down’s syndrome?

Answer 3

• General joint laxity
  
  • Atlantoaxial joint (careful to avoid neck dislocation)
• Poor muscle tone
• Spinal cord compression

Question 4

Is a patient with Down’s syndrome able to give consent for the examination?

Answer 4

• Depends based on their capacity to consent
  
  • Understand, retain, and weigh the information
  • Communicate their decision

Question 5

What are extraoral characteristics of individuals with Down’s syndrome?

Answer 5

• Short stature
• Short neck
• Obesity
• Short limbs
• Broad head and sloping forehead
• Round face
• Large lips
• Flat nasal bridge
• Oblique slanting eye fissures
• Epicanthic skin folds on the inner corner of the eyes
• White spots on the iris
• Short stubby hands and fingers
• Inward-curving fifth finger

Question 6

What are oral features of Down’s syndrome?

Answer 6

• Fissured lips
• Open-mouth posture and mouth-breathing
• Tongue position
• Lack of muscle tone
• Fissuring of the dorsal surface of the tongue
• Drooling
• Bruxism
• Developmental absence of some teeth
• Teeth with short conical roots
• Interdental spacing
• Delayed eruption
• Small teeth, including ocnical crown forms
• Shallow fissures
• Hypoplastic/hypocalcified enamel
• Class 3 skeletal pattern and malocclusion
• Taurodontism
• Prone to periodontal disease
• Prone to intraoral candidal infection and angular chelitis
• Resistant to dental caries (sIgA and high salivary pH)

Question 7

Is refusal or delay of treatment an appropriate resposne?

Answer 7

No. It would be considered negligence.