Orthodontics · patient case with 1 question
A young man who snores, with a Class III bite
Patient: Male, 24 years old
Chief Complaint: “I snore badly, I am exhausted all day, and my bottom teeth sit in front of my top ones.”
Background: BMI 34. Polysomnography confirms moderate obstructive sleep apnea with an AHI of 22. He has tried CPAP and tolerates it poorly. Hand-wrist films and serial records confirm that growth is complete.
Vital Signs: BP 136/86 mmHg · HR 78 bpm · Neck circumference 17.5 in
Findings: Skeletal Class III with maxillary retrusion. Angle Class III molar and canine relationships with a reverse overjet of 4 mm. Cephalometric ANB −4°. Mallampati class III airway, large tongue, low hyoid position.
Question 1
What is the most appropriate definitive treatment?
Show answer and explanation
Correct answer: D. Orthodontics combined with orthognathic surgery
- A. A mandibular advancement device is a reasonable option for mild to moderate apnea in a patient who declines CPAP — but it works by protruding the MANDIBLE, which in a skeletal Class III with an existing reverse overjet would worsen the occlusion. It is also symptomatic management rather than definitive correction.
- B. Camouflage moves teeth to disguise a skeletal discrepancy. At an ANB of −4° with 4 mm of reverse overjet the discrepancy is beyond what dental compensation can hide, and camouflage typically involves retroclining the lower incisors — which does nothing for the airway and can reduce tongue space.
- C. Growth modification with functional appliances, or maxillary protraction with a face mask, requires REMAINING GROWTH. At 24 with confirmed skeletal maturity that window has closed.
- D. CORRECT. Growth is complete and the discrepancy is genuinely SKELETAL, which makes combined orthodontic and surgical management the definitive approach: presurgical orthodontic decompensation, then orthognathic surgery. The elegance of it in this patient is that MAXILLOMANDIBULAR ADVANCEMENT enlarges the pharyngeal airway by advancing the skeletal framework to which the soft palate, tongue base and suprahyoid muscles attach — it is the most effective surgical treatment for obstructive sleep apnea short of tracheostomy. One plan addresses both the occlusion and the airway.
Note: A skeletal Class III pattern produces a CONCAVE profile — retrusive midface, prominent chin. Convexity belongs to Class II. Treat that as a transcription slip in the recall rather than a feature of the case. Also worth noting: weight loss and CPAP remain first-line MEDICAL management of OSA, and the surgical plan does not displace them.