Mandibular bone exposure and osteonecrosis as a complication of general anaesthesia Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=iups20 Upsala Journal of Medical Sciences ISSN: 0300-9734 (Print) 2000-1967 (Online) Journal homepage: https://www.tandfonline.com/loi/iups20 Mandibular bone exposure and osteonecrosis as a complication of general anaesthesia Mohammad Kharazmi, Lillemor Björnstad, Pär Hallberg, Jonas Wanbro, Anders-Petter Carlsson, Samandar Habib & Gunnar Warfvinge To cite this article: Mohammad Kharazmi, Lillemor Björnstad, Pär Hallberg, Jonas Wanbro, Anders-Petter Carlsson, Samandar Habib & Gunnar Warfvinge (2015) Mandibular bone exposure and osteonecrosis as a complication of general anaesthesia, Upsala Journal of Medical Sciences, 120:3, 215-216, DOI: 10.3109/03009734.2015.1010667 To link to this article: https://doi.org/10.3109/03009734.2015.1010667 © Informa Healthcare Published online: 17 Mar 2015. Submit your article to this journal Article views: 334 View related articles View Crossmark data Citing articles: 5 View citing articles https://www.tandfonline.com/action/journalInformation?journalCode=iups20 https://www.tandfonline.com/loi/iups20 https://www.tandfonline.com/action/showCitFormats?doi=10.3109/03009734.2015.1010667 https://doi.org/10.3109/03009734.2015.1010667 https://www.tandfonline.com/action/authorSubmission?journalCode=iups20&show=instructions https://www.tandfonline.com/action/authorSubmission?journalCode=iups20&show=instructions https://www.tandfonline.com/doi/mlt/10.3109/03009734.2015.1010667 https://www.tandfonline.com/doi/mlt/10.3109/03009734.2015.1010667 http://crossmark.crossref.org/dialog/?doi=10.3109/03009734.2015.1010667&domain=pdf&date_stamp=2015-03-17 http://crossmark.crossref.org/dialog/?doi=10.3109/03009734.2015.1010667&domain=pdf&date_stamp=2015-03-17 https://www.tandfonline.com/doi/citedby/10.3109/03009734.2015.1010667#tabModule https://www.tandfonline.com/doi/citedby/10.3109/03009734.2015.1010667#tabModule Upsala Journal of Medical Sciences. 2015; 120: 215–216 LETTER TO THE EDITOR Mandibular bone exposure and osteonecrosis as a complication of general anaesthesia MOHAMMAD KHARAZMI1,2, LILLEMOR BJÖRNSTAD1, PÄR HALLBERG3, JONAS WANBRO4, ANDERS-PETTER CARLSSON1,5, SAMANDAR HABIB6 & GUNNAR WARFVINGE7 1Department of Oral and Maxillofacial Surgery, Central Hospital, Västerås, Sweden, 2Section of Orthopaedics, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden, 3Department of Medical Sciences, Uppsala University, Uppsala, Sweden, 4Department of Anaesthesia and Intensive Care, Central Hospital, Västerås, Sweden, 5Section of Oral and Maxillofacial Surgery, Department of Surgical Sciences, Uppsala, Sweden, 6School of Medicine, Uppsala University, Uppsala, Sweden, and 7Department of Oral Pathology, Malmö University, Malmö, Sweden Trauma to the oral structures sometimes occurs as a complication to general anaesthesia. We here report two cases of an unusual type, mandibular osteone- crosis. To our knowledge, there has been only one previous publication of this condition (1). The first case was a 69-year-old man who under- went oral examination 3 months prior to planned cardiac surgery. His medical history included hyper- tension, diabetes mellitus, and mitral insufficiency, and he was on treatment only with enalapril. Three molars in his lower jaw were extracted due to peri- odontitis, and healing was uneventful at follow-up. At cardiac surgery, he was intubated with a standard endotracheal tube (number 8) and was placed on a cardio-pulmonary bypass (CPP) machine. Two weeks later, he complained of pain in the right side of his mandible, which had started directly after recovery from surgery and successively increased. Examination revealed a 4 � 8 mm area of exposed non-vital bone at the right mylohyoid ridge. There was no sign of infection, and radiography was unremarkable. He was treated with 2 mg/mL chlorhexidine mouth rinse twice daily and amoxicillin 500 mg three times daily. Three weeks later there was spontaneous exfoliation of a sequestrum, and there was complete healing 2 months after his cardiac surgery. The other case was an 86-year-old man with pro- gressive aorta stenosis and a history of myocardial infarction. Medication included enalapril, isosorbide mononitrate, simvastatin, acetylsalicylic acid, and glyceryl trinitrate. He was planned for cardiac surgery and underwent oral examination 2 months before. Two upper and three lower molars were extracted due to apical periodontitis, and healing was uneventful at follow-up. At cardiac surgery, the patient was intu- bated with a standard endotracheal tube (number 8) and placed on a CPP machine. Two weeks later, he complained about right-sided mandibular pain, which had started directly after recovery from surgery. Exam- ination revealed an 8 � 5 mm area of non-vital exposed bone at the right mylohyoid ridge. There was no sign of infection, and radiography was unre- markable. He was treated with 2 mg/mL chlorhexidine mouth rinse twice daily and phenoxymethylpenicillin 1 g three times daily, and there was complete healing 2 months after surgery preceded by exfoliation of a small sequestrum. The incidence of osteonecrosis as here described is unknown. It is probably low, but the location at the medial aspect of the mandible could make it easily mistaken for discomfort after intubation (2). The pathogenesis is unclear, but the prominence of Correspondence: Mohammad Kharazmi DDS, Department of Oral and Maxillofacial Surgery, Central Hospital, Västerås, SE-721 89 Västerås, Sweden. Fax: +46 21 17 54 30. E-mail: kharazmi.mohammad@gmail.com (Received 22 December 2014; accepted 8 January 2015) ISSN 0300-9734 print/ISSN 2000-1967 online � 2015 Informa Healthcare DOI: 10.3109/03009734.2015.1010667 http://informahealthcare.com/journal/ups mailto:kharazmi.mohammad@gmail.com the mandibular shelf, covered by only a thin layer of oral mucosa, is probably vulnerable to trauma, which may affect the blood supply to the periosteum leading to local ischemia and osteonecrosis. Another possi- bility could be soft tissue necrosis caused by several hours of pressure from the endotracheal tube or the transesophageal echocardiograph with its bite blocks. Although the anaesthesiologists reported no proce- dural complications, reduced blood pressure could have aggravated the condition through diminished blood flow in the soft tissue. In a previously published case series (Table I), it appears that the affected area was at the right side of the posterior part of the mandible in all cases, indicating that trauma from the laryngoscope blade was a possible cause (1). Although the exact mechanism involved in this type of osteonecrosis remains unknown (2), we believe that an association with general anaesthesia in our cases is very likely. There was no history of bisphosphonate use or radiation treatment, and follow-up oral exam- ination prior to surgery showed no sign of osteone- crosis. Also, the onset of mandibular pain was right after recovery from anaesthesia in both cases. Factors that may predispose to this type of osteo- necrosis include prominent mandibular shelves, lim- ited mouth opening, and extensive oral manipulation while managing the airway during anaesthesia. Previous or ongoing treatment with bisphosphonates or radiation might also lead to more severe complica- tions in affected patients. We hope that our reported cases will increase the awareness of this type of complication to general anaesthesia. Acknowledgements All authors contributed to this study and in the writing of the manuscript. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. References 1. Almazrooa SA, Chen K, Nascimben L, Woo SB, Treister N. Case report: osteonecrosis of the mandible after laryngoscopy and endotracheal tube placement. Anesth Analg. 2010;2: 437–41. 2. Fisher QA. True, true–but how related? Bony necrosis and sequestration in the mandible after endotracheal intubation. Anesth Analg. 2010;2:272–3. Table 1. Summary of cases in the literature and the present report. Age/ gender Location of osteonecrosis Duration of intubation (hours) Osteonecrosis visualized by radiography Symptoms Onset of symptoms after general anaesthesia Treatment Time until healing Case 1a 49F Posterior, right side of mandible 2.5 Yes (CT) Oral pain After 1 week Non-surgical removal of the sequestrum. Chlorhexidine rinse. Within 1 week Case 2a 60M Posterior, right side of mandible 3 Yes (plain X-ray) Oral pain Immediately after recovery Non-surgical removal of the sequestrum. Chlorhexidine and saline rinse. 2 weeks Case 3a 47F Posterior, right side of mandible 1.5 NA Oral pain Immediately after recovery Non-surgical removal of the sequestrum. Amoxicillin. NA Case 4a 67F Posterior, right side of mandible 1.75 NA Soreness and oral pain After 1 day Non-surgical removal of the sequestrum. Chlorhexidine rinse. Within 1 week Case 1b 69M Posterior, right side of mandible 4.5 No (plain X-ray) Oral pain Immediately after recovery Amoxicillin. Chlor- hexidine rinse. 6 weeks Case 2b 86M Posterior, right side of mandible NA No (plain X-ray) Oral pain Immediately after recovery Phenoxymethylpenicil- lin. Chlorhexidine rinse. 7 weeks aAlmazrooa SA et al, 2010 (1). bPresent report. NA = not available. 216 M. Kharazmi et al. http://www.ncbi.nlm.nih.gov/pubmed/20495140?dopt=Abstract http://www.ncbi.nlm.nih.gov/pubmed/20495140?dopt=Abstract http://www.ncbi.nlm.nih.gov/pubmed/20664092?dopt=Abstract http://www.ncbi.nlm.nih.gov/pubmed/20664092?dopt=Abstract ss1 Acknowledgements Declaration of interest References