Differential Diagnosis for Patient's Mouth Stuck Open While Yawning
- Single Most Likely Diagnosis
- Temporomandibular joint (TMJ) dislocation: This condition occurs when the jawbone (mandible) becomes displaced from its normal position in the joint, often happening during activities that involve wide opening of the mouth, such as yawning. The sudden, forceful movement can cause the jaw to become stuck in an open position.
- Other Likely Diagnoses
- TMJ subluxation: Similar to dislocation but less severe, where the jaw partially displaces but can sometimes reduce spontaneously or with less force.
- Trismus: A condition characterized by spasms of the muscles of mastication, which can limit the range of motion of the jaw, potentially causing the mouth to become stuck in an open position if the spasms occur during yawning.
- Dystonic reaction: A type of movement disorder that can cause involuntary muscle contractions, potentially affecting the jaw and leading to abnormal postures, including the mouth being stuck open.
- Do Not Miss Diagnoses
- Stroke or Transient Ischemic Attack (TIA): Although less common, a stroke or TIA affecting the brainstem or the cranial nerves controlling facial and jaw movements could potentially cause sudden, unexplained weakness or paralysis leading to the jaw becoming stuck.
- Tetanus infection: Characterized by muscle stiffness and spasms, tetanus could theoretically cause the jaw muscles to lock in place, although this would be accompanied by other systemic symptoms.
- Rare Diagnoses
- Eagle syndrome: A condition involving an elongated styloid process or calcified stylohyoid ligament, which can cause pain and limited mobility of the jaw, potentially leading to the sensation of the mouth being stuck open.
- Myasthenia gravis: An autoimmune disease that affects the nerve-muscle connection, leading to weakness and rapid fatigue of the muscles under voluntary control. In rare cases, this could affect the muscles of mastication and lead to jaw weakness or abnormal positioning.