Pronounced mediastinal emphysema after restorative treatment of the lower left molar—a case report and a systematic review of the literature

Abstract

This case report presents an iatrogenic induced mediastinal emphysema after restorative treatment of the lower left second molar, aimed to highlight the potential life-threatening consequences, and providing diagnostics and treatment concepts of complicated dental induced emphysema based on literature review. A 74-year-old female patient was admitted to the emergency department due to a fall on her shoulder. Additional finding was a significant swelling of the face and neck. In the computer tomography of the head, neck, and thorax, a humerus fracture and pronounced soft tissue emphysema from the infraorbital region to the mediastinum was detected. The patient reported that she had been treated by her dentist 4 days earlier. The treatment had to be discontinued after beginning of a pronounced swelling. Other reasons for the emphysema could be excluded out on an interdisciplinary teamwork. The patient was monitored as an inpatient for 5 days and received intravenous antibiotic therapy. This case report shows the rare complication of pronounced mediastinal emphysema after root canal treatment. Emphysema should always be a differential diagnosis of soft tissue swelling and, in case of doubt, a general medical presentation should be made.

A swollen face and neck after dental surgery: Think of subcutaneous emphysema and pneumomediastinum

“…A review of the literature, from 1973 until August 2023, reveals a total of 44 reported cases of pneumomediastinum following a single dental extraction, usually resulting from the use of high-speed dental drills, which is designed for cutting teeth and uses air or air and water to cool the dental bur [ 1 , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] ]. The mandibular molars are more frequently involved, which is not only supported by the presented case, but also by 21 of the 33 cases (63.6 %) reported by Spille et al [ 2 , 5 ]. In particular the removal of the second and third molar from the lower jaw seems to be the main reason for development of mediastinal emphysema.…”

“…The roots of the second and third mandibular molars are in connection with the submandibular space. Therefore, air can diffuse from the submandibular space to the parapharyngeal space and subsequently to the retropharyngeal space, which is believed to be the main route of communication between the mouth and the mediastinum [ 1 , [5] , [6] , [7] , [8] , 12 ].…”

“…However, when the subcutaneous emphysema is extending to the thorax it can cause possible life-threatening complications, such as airway obstruction, pneumomediastinum, pneumothorax or pneumopericardium. Isolated subcutaneous emphysema is generally painless, but if it is accompanied by dyspnoea, chest pain or dysphagia it should raise awareness for the possibility of a pneumomediastinum [ 2 , 5 , 7 , 8 , 12 ].…”

“…In the majority of cases, this is a complication due to abdominal operations, head and neck surgery, dental surgery, intubation, mechanical ventilation, endoscopic procedures, pleural cavity instrumentation, central vascular access procedures and chest operations. However, it has also been described as a rare complication following a routine dental extraction [ [2] , [3] , [4] , [5] ]. It is assumed that this complication is underdiagnosed.…”

“…Since life-threatening complications can emerge from subcutaneous emphysema extending into the mediastinum, it is important to recognize the symptoms and clinical signs and to raise awareness that it can develop after different dental treatments. To highlight the importance of including this presumably underdiagnosed complication in the differential diagnosis, we present a case of pneumomediastinum and subcutaneous emphysema, which developed following a second molar extraction with an air-turbine handpiece [ 2 , 5 , 7 ].…”