Temporomandibular joint dislocation due to acute propranolol intoxication

Area of Science:

• Pharmacology
• Emergency Medicine
• Orthopedics

Background:

• Temporomandibular joint (TMJ) dislocation is a rare condition.
• Beta-blocker toxicity is not a commonly recognized cause of TMJ dislocation.
• Propranolol is a widely used beta-blocker with potential for severe toxicity.

Purpose of the Study:

• To report the first documented cases of TMJ dislocation secondary to acute propranolol toxicity.
• To investigate the potential mechanism linking propranolol toxicity to TMJ dislocation.

Main Methods:

• Case report of two patients admitted with severe acute propranolol toxicity.
• Clinical diagnosis of bilateral TMJ dislocation based on physical examination.
• Documentation of successful manual reduction and follow-up for recurrence.

Main Results:

• Two patients with severe acute propranolol intoxication developed bilateral TMJ dislocation.
• No prior history of TMJ dislocation or other predisposing factors were present in the patients.
• Successful reduction of TMJ dislocation was achieved in both cases with no recurrence within two weeks post-discharge.

Conclusions:

• Acute severe propranolol toxicity can be a novel cause of TMJ dislocation.
• Spastic contraction of the lateral pterygoid muscle is proposed as the likely mechanism.
• This finding challenges previous hypotheses implicating masseter muscle contraction in bilateral TMJ dislocation.