Quartz 4

OFP Mock Formative Q3 - Obstructive Sleep Apnoea

4 min read

Mock OSCE Question 3

David is a 54-year-old male referred to your clinic by his general medical practitioner. He reports loud snoring, excessive daytime sleepiness — including falling asleep at his desk during the working day — and unrefreshing sleep. His partner has observed episodes in which he stops breathing during the night. He has a BMI of 32 and a known history of hypertension managed with antihypertensive medication. On examination you note a Class II skeletal pattern with a retrognathic mandible, a high Mallampati score, and clinical evidence of bruxism. His referring practitioner suspects obstructive sleep apnoea (OSA) and has asked you to assess and manage him.

  1. List 3 risk factors for OSA that are present in this patient. (3 marks)
  2. Explain the pathophysiology of OSA and describe how it relates to oral manifestations. (3 marks)
  3. Describe the role of the dentist in screening and diagnosing OSA. (3 marks)
  4. Outline 2 oral appliances commonly used in OSA management and explain their mechanisms of action. (3 marks)
  5. Describe 2 complications of untreated OSA relevant to dental and systemic health. (3 marks)
  6. List 3 non-pharmacological lifestyle modifications that may reduce the severity of OSA. (3 marks)
  7. What challenges may arise in the long-term management of OSA with oral appliance therapy? (3 marks)

Total: 21 marks

First try answers

  • 1
    • Class II skeletal pattern with retrognathic mandible
    • Hypertension
    • Obesity
  • 2
    • cant keep airway open , dry mouth?
  • 3
    • administer screening questionnaires (STOP BANG)
    • administer MAS
    • Referral to specialist
  • 4
    • tongue suck
    • mandible advancement
  • 5
    • depression
    • high risk for myocardial infarction
  • 6
    • Weight loss
    • Stress management
    • sleep hygiene / sleeping on sid e
  • 7
    • development of malocclusion
    • higher risk for candidosis ?

Marking Key

Risk Factors OSA

  • Male Gender
  • BMI over 32
  • Hypertension
  • Retrognathia (craniofacial risk factor for upperairway narrowing)
  • High Mallamptai score (indicating upper airway crowing )

Pathophysiology of OSA and describe how it relates to oral manifestations

  • OSA results from repetitive collapse of the upper airway during sleep due to loss of pharyngeal muscle tone
  • collapse leads to intermittent hypoxia and hypercapnia
  • arousal responses cause sleep fragmentation and sympathetic nervous system activation
  • increased respiratory effort and jaw bracing during airway obstruction may contribute to masticatory muscle hyperactivity and sleep bruxism
  • chronic mouth breathing secondary to upper airway obstruction can cause xerostomia and increased risk of dental caries

**Role of the Dentist in screening and Diagnosing OSA **

  • Identify risk factors through comprehensive history-taking and oral examination
  • Use validated screening tools (e.g. STOP-BANG questionnaire, Epworth Sleepiness Scale)
  • Recognize oral and craniofacial signs associated with OSA (e.g. retrognathia, macroglossia, scalloped tongue, high arched palate, enlarged tonsils, bruxism )
  • Refer to a sleep physician for definitive diagnosis via polysomnography (in-laboratory) or home sleep testing

Outline 2 oral appliances commonly used in OSA management and explain their mechanisms of action

  • tongue retaining devises (TRDs)
    • Hold the tongue in an anterior position via a negative pressure bulb, preventing posterior displacement of the tongue and pharyngeal obstruction
  • Mandibular advancement appliances (MAAs/ MADs):
    • protrude the mandible anteriorly to enlarge the upper airway, increase pharyngeal muscle tone and reduce upper airway collapsibility during sleep

Describe 2 complications of untreated OSA relevant to dental and systemic health

  • Dental/orofacial:
    • sleep bruxism
    • Temporomandibular disorders
    • Xerostomia
    • Increased caries risk
    • periodontal disease exacerbation
  • Systemic:
    • hypertension
    • increased risk of cardiovascular disease and stroke
    • type 2 diabetes
    • neurocognitive impairment
    • excessive daytime sleepiness impairing occupational and driving safety **Non- Pharmacological Modifications to OSA **
  • weight reduction
  • Positional therapy (avoidance of supine sleeping )
  • reduction or elimination of alcohol and sedatives beofre sleep
  • smoking cessation
  • regular physical exercise

Challenges for long-term management of OSA with oral appliance therapy

  • patient non-compliance iwth nightly appliance use
  • orofacial discomfort, tooth soreness or TMJ pain
  • Appliance induced occlusal changes and anterior open bite over time
  • need for ongoing titration, monitoring and review of treatment efficacy
  • appliance wear, fracture or deteriortation requiring replacement

Graph View