Pneumomediastinum as a Complication of Oral and Maxillofacial Injuries: Report of 3 Cases and a 50-Year Systematic Review of Case Reports

Abstract

Objectives: Pneumomediastinum (PM) secondary to oromaxillofacial trauma (OMF) is a rare but well-described complication/pathologic finding. The aim of this study was twofold: first, to report our experience in treatment of maxillofacial trauma patients with PM, and second, to review the literature regarding the clinical features, severity, course, and management of the aforementioned complication.

Material and methods: We retrospectively reviewed the medical records and charts of patients who suffered from maxillofacial trauma and treated in our hospital between September 1, 2013 and September 31, 2017. The inclusion criteria were patients with radiologically confirmed PM. In addition, the electronic databases PubMed, Scopus, and Science Direct were queried for articles reporting PM cases secondary to OMF injuries and published in English, French, and German language.

Results: Three cases of PM out of 3,514 cases of craniomaxillofacial trauma were found; there were 3 male patients who presented in our emergency department with the chief complaint of cervicofacial swelling. Literature search isolated 58 selected articles and 63 cases were assessed in total; posttraumatic repeated blowing of nose was proved as most frequent triggering factor among them. Furthermore, the outcomes of review showed that thoracic pain, respiratory distress, and swallowing difficulties were not frequently reported in patients with ME due to facial trauma.

Conclusions: Both our experience and the results of systematic literature review indicated that patients with PM due to OMF injuries present mild clinical course. If properly managed, this specific pathologic condition may have no further complications or relative comorbidities. The exact etiology and mechanism of PM in the context of maxillofacial injuries always needs to be identified. Radiographic, laboratory, and endoscopic examinations should be applied to rule out the more serious and frequently diagnosed aerodigestive, thoracic, and abdominal causes of PM.

Keywords: Hamman’s syndrome; cervicofacial emphysema; facial trauma; maxillofacial fracture; mediastinal emphysema; pneumomediastinum.

Figure 1.

Evidence search and selection.

Figure 2.

A 38-year-old male patient presented to ED because of an assault-related injury. He chiefly complained for inability to open his right eye owing to periorbital ecchymosis and oedema. The patient was hemodynamically stable, fully orientated without alteration of mental status, and denied any chest pain, respiratory distress, or visual disturbances. Crepitation was apparent on palpation of right periorbital and midcheek area. Emergency computed tomography (CT) scan of head, neck, and thorax was conducted. CT findings evidenced a facial emphysema extended along the neck and up to superior mediastinum and a non-displaced fracture of the right zygomatico-maxillary complex (Figure 2a and b). Air also found in the right orbital cavity and periorbital region (Figure 2c). He was discharged 5 days later without evidence of residual PM in follow-up CT.

Figure 3.

A 45-year-old male patient was admitted on our emergency department 2 hours after accidental fall from a height of 2 m. He presented with right periorbital edema and ecchymosis, and complained of unilateral moderate facial and chest pain, after forceful nose blowing and multiple episodes of sneeze. Full-body CT scan revealed linear undisplaced fractures involving the right: anterior sinus wall and orbital floor (Fig. 3a, red arrow), anterior and posterior tables of frontal sinus (Fig. 3a and b, green and white arrows), and roof and posterior wall of sphenoid sinus. These findings were accompanied by the presence of PM (Fig. 3c, yellow arrow), cervicofacial emphysema (Fig. 3d), orbital emphysema and pneumocephalus (Fig. 3b). The patient was discharged 9 days later and both PM and pneumocephalus had completely resolved in follow-up CT.

Figure 4.

A 63-year-old male patient with the presenting sign of closed rhinolalia who diagnosed with retropharyngeal emphysema (Fig. 4a, yellow arrows) and PM (Fig. 4b, green arrow) due to a linear and nondisplaced fracture of right anterior sinus wall extending to the base of frontal process of ipsilateral maxillary bone (Fig. 4c). He mentioned multiple attempts of forceful nasal blowing shortly after a motorcycle accident. He was admitted in our clinic, and interruption in use of his face mask for continuous positive airway pressure due to history of sleep apnea was applied. Patient’s course was uncomplicated and he was discharged 5 days later, with almost complete resolution of cervicofacial emphysema and absence of residual PM in follow-up imaging tests.