Anesthesia · patient case question
Which anaesthetic technique is required to extract tooth #19?
Patient case: Adolescent with Duchenne muscular dystrophy
Patient: Male, 15 years old, in a wheelchair
Chief complaint: “My back tooth is broken and it hurts.”
History: Duchenne muscular dystrophy diagnosed at age 4. His father is unaffected and his mother is a known carrier. He has one sister.
Findings: Non-restorable tooth #19. Limited mouth opening. Macroglossia is noted. Poor oral hygiene owing to reduced upper limb strength.
Show answer and explanation
Correct answer: B. Inferior alveolar nerve block
- A. An intrapapillary injection anaesthetises the interdental papilla for rubber dam or matrix placement. It provides no pulpal anaesthesia.
- B. CORRECT. Mandibular molars require an INFERIOR ALVEOLAR NERVE BLOCK. The dense cortical bone of the adult mandible in the molar region does not allow reliable diffusion from a buccal infiltration, so the nerve must be anaesthetised proximally, at the mandibular foramen, before it enters the canal. A long buccal supplement is added for the buccal soft tissue during extraction.
- C. The posterior superior alveolar block covers the MAXILLARY molars. Wrong arch.
- D. Buccal infiltration alone is reliable in the MAXILLA, where the cortical plate is thin and porous, and in the mandible only for primary teeth and permanent incisors. It fails at mandibular molars.
Note: Duchenne-specific considerations: progressive respiratory muscle weakness and impaired cough make general anaesthesia and deep sedation genuinely hazardous, so local anaesthesia in the chair is preferred where possible. Cardiomyopathy is near-universal by adolescence, so a cardiology review is worthwhile before extensive care, and the patient may need support to maintain an upright, safe airway position.