Lung Abscess Resulting From Aspiration Pneumonia Following Orthognathic Surgery With Le Fort I and Sagittal Split Ramus Osteotomies.

Intermaxillary fixation (IMF) is commonly performed following orthognathic surgery, including Le Fort I osteotomy and sagittal split ramus osteotomy, to maintain the planned occlusion. Although perioperative pulmonary complications are rare in healthy young adults, we encountered a case of lung abscess that developed from aspiration pneumonia during the period of IMF. Here, we report the case with a review of the literature. The patient was a 22-year-old man with bilateral cleft lip and palate, presenting with class III malocclusion due to maxillary hypoplasia. Orthognathic surgery (Le Fort I osteotomy and sagittal split ramus osteotomy) was performed to improve facial appearance and occlusion. Postoperatively, he developed a fever, and his oxygen saturation decreased. On postoperative day (POD) 8, chest radiography and CT revealed pneumonia in the left lower lobe, and antibiotic therapy was initiated. Despite treatment, his condition persisted, and a repeat CT on POD 15 showed progression to a lung abscess. A string test-positive Klebsiella pneumoniae (Kp) was identified as the causative organism. Upon switching to broad-spectrum antibiotics, the inflammatory response subsided, and antibiotic treatment was completed on POD 43. Severe aspiration pneumonia is rare in young patients without underlying disease. In this case, IMF and infection with a string test-positive Kp led to abscess formation, complicating treatment. This highlights the importance of early detection and treatment of pneumonia during the period of IMF.