History of jaw dislocation? A specific query to be made during all preanesthetic assessments

Sir, Most patients during conduct of general anesthesia require jaw thrust and chin lift as upper airway obstruction is common owing to the tongue falling back. These maneuvers can result in dislocation of jaw, especially in those with unstable temporomandibular joints (TMJs). We are reporting a case of a 68-year-old-male patient posted for direct laryngoscopy and biopsy for a vocal cord lesion. He was edentulous with sunken cheeks. For the procedure, he was induced with propofol and paralyzed with a short-acting relaxant like succinylcholine to facilitate intubation as we anticipated difficult mask ventilation. As he became unconscious and apnoeic, mask ventilation was initiated, which was found to be difficult. Jaw thrust and chin lift were given to open up airway, and gauze pads were kept over both cheeks to reduce leaks. Patient was ventilated for 1 min. On removing the face mask for intubation, it was noticed that lower jaw was dislocated and the mouth remained wide open. The dislocation was then reduced without difficulty by the intraoral closed reduction technique. Following reduction, the patient was intubated and atracurium 15 mg was given. After completion of surgical procedure, anesthetic agents were discontinued, neuromuscular blockade was reversed, and a nasopharyngeal airway introduced after decongesting and lubricating one nostril. The patient was extubated when fully awake. In the postoperative period, when the patient was quizzed about any previous history of jaw dislocation, he disclosed that he had multiple incidents of jaw dislocation in the past. During the preanesthetic evaluation, he did not disclose it as he thought it was irrelevant. TMJ dislocation is a common problem associated with airway manipulation, especially in sedated or anesthetized patients [1]. It involves dislodgement of the condyle from its normal position in the squamotemporal portion of the cranial base [2,3]. Dislocation can happen spontaneously or associated with trauma, laryngoscopy, intubation, endoscopy, or yawning. Hypermobility and subluxation of TMJ has a prevalence of up to 25–50% in the general population and is common in middle-aged females [4]. During preoperative evaluation, limitation of range of motion of the TMJ, ability to voluntarily protrude lower jaw, history of previous injury to jaw, periauricular pain, and any clicking or grating sounds during jaw movements should be noted [5]. In patients with prior history of jaw dislocation, airway manipulation should be gentle. Use of nasopharyngeal airway once patient is unconscious could help to avoid jaw thrust to relieve airway obstruction while holding face mask. Delaying extubation till patient is fully awake avoids mask holding in a sedated state. Reduction of dislocated mandible is easy and is performed intraorally. Place both thumbs orally on the lower molars or on the ridge of mandible posterior to the molars, and the other fingers should be wrapped externally around the mandible. Then firm, slow, and steady pressure is applied in a downward and posterior direction. Following successful TMJ reduction patient will be able to close the mouth. These patients are prone for recurrent TMJ dislocation and hence constant vigil is required for early diagnosis of the same in the intraoperative and immediate postoperative period. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.