Differential Diagnosis for Masseter Muscle Trembling

• Single most likely diagnosis
  • Bruxism: This condition, characterized by involuntary grinding or clenching of the teeth, is a common cause of masseter muscle trembling. The repeated contraction and relaxation of the masseter muscle can lead to trembling or spasms.
• Other Likely diagnoses
  • Anxiety or Stress: High levels of anxiety or stress can cause muscle tension, including in the masseter muscle, leading to trembling.
  • Caffeine or Nicotine Withdrawal: Withdrawal from caffeine or nicotine can cause muscle tremors, including in the masseter muscle.
  • Dental Problems: Issues like temporomandibular joint (TMJ) disorders or dental pain can lead to masseter muscle spasms or trembling.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Thyroid Storm: Although rare, a thyroid storm (a life-threatening complication of untreated or undertreated hyperthyroidism) can cause muscle tremors, including in the masseter muscle.
  • Neurological Disorders: Conditions like Parkinson's disease, multiple sclerosis, or peripheral neuropathy can cause muscle tremors, including in the masseter muscle.
• Rare diagnoses
  • Hemifacial Spasm: A rare neurological disorder characterized by involuntary muscle spasms on one side of the face, including the masseter muscle.
  • Dystonia: A movement disorder that can cause involuntary muscle contractions, leading to repetitive movements or abnormal postures, including masseter muscle trembling.
  • Botulism: A rare but serious illness caused by a toxin that can cause muscle weakness, including in the masseter muscle, leading to trembling or difficulty swallowing.