Nitrous oxide laughing matter

368 inevitable exposure to the infection perhaps unwittingly so given that approximately 18,100 (17%) people living with HIV in the United Kingdom (UK) are unaware of their HIV positive status. There is therefore a need for guidance specific to oral and maxillofacial surgery (OMFS) procedures to establish an acceptable threshold of known and unknown risk to both the patient and OMFS personnel with regard to HIV infection, both diagnosed and undiagnosed. Objectives: We explore the surgical opinion of OMFS surgeons within the UK on managing the HIV positive OMFS patient. Methods: An online questionnaire was performed to assess the current awareness of HIV and its management, establish opinions, concerns and the incumbent challenges involved in managing such patients in the context of OMFS. Findings: The majority of clinicians felt they had limited knowledge on the complexities involved in managing such patients and sort clearer additional guidance on how to best optimise this patient group. Conclusion: Clearer guidance is required in the management of the HIV positive OMFS patient and this study will help to inform this. http://dx.doi.org/10.1016/j.ijom.2017.02.1237 Sialoendoscopy for treatment of obstructive sialadenitis D. Hirjak ∗ , I. Kupcova, M. Beno, B. Galis Department of Oral and Maxillofacial Surgery, Comenius University, University Hospital Ruzinov, Bratislava, Slovakia Background: Salivary duct obstruction is a common disease of the major salivary glands. Sialolithiasis and other aetiologies including inflammation, strictures, mucous plugs, foreign bodies, kinks are possible causes of obstructive salivary gland diseases. Traditional diagnostic imaging, plain radiography, ultrasonography, computed tomography (CT) and others cannot identify the aetiology and location of obstruction. Sialoendoscopy is a relatively new minimally invasive method that enables direct visualisation of the ducts of the major salivary glands. Besides the diagnostic options, interventional sialoendoscopy allows therapeutical intervention. Present analysis was performed to assess the effectiveness of interventional sialoendoscopic treatment of obstructive sialadenitis of major salivary glands. Methods: This is a retrospective study of 41 patients with obstructive sialadenitis of submandibular and parotid glands who underwent sialoendoscopy between 2010 and 2015. The symptoms and clinical findings were confirmed by plain radiographs, CT scans and ultrasonography. Various interventional sialoendoscopic techniques were used, dilation of strictures and irrigation, stone retrieval by basket and stone removal by endoscopic-assisted transmucosal incision. Results: Symptomatic relief was achieved in 39 patients. Dilatation and lavage of the duct system without stone was accomplished in 17 patients. Sialoliths were removed in 24 patients. Conclusion: Sialoendoscopy is a useful minimally invasive interventional technique for direct visual detection of cause of obstruction and enables us for therapeutic options. http://dx.doi.org/10.1016/j.ijom.2017.02.1238

Maxillomandibular-chin surgical advancement for patients with obstructive sleep apnoea — review of 13 patients L.I. Ho ∗ , S.C. Fung Dentistry and Maxillofacial Surgery, United Christian Hospital, Hong Kong Background and Objectives: This is to share our experience in the management of patients with obstructive sleep apnoea via the maxillomandibular-chin surgical advancement and to review the treatment outcomes. Methods: Patients with obstructive sleep apnoea underwent maxillomandibular advancement between 2011 and 2016 were included. No pre- and postoperative orthodontics treatment was performed in all patients. Maxillomandibular advancement of 1 cm with or without advancement genioplasty in trapezoid mortised design and concomitant intrapharyngeal soft tissue surgery were performed dictated by the preoperative polysomnography and drug-induced sleep endoscopy. Surgical cure was defined as postoperative apnoea-hypopnoea index (AHI) of fewer than 5 events/h. Surgical success was defined as postoperative AHI with more than 50% reduction to fewer than 20 events/h. Findings: A total of 13 male patients with age ranging from 32–67 years (mean, 51 years) were included. 12 patients had maxillomandibular-chin advancement. The remaining patient had maxillomandibular advancement as he had genioplasty done earlier. Six patients had concomitant intrapharyngeal soft tissue surgery. Mean reduction of AHI was 85.5%. The mean lowest oxygen saturation was improved from 71.4% to 86.5% postoperatively. Eight patients achieved surgical cure and four patients achieved surgical success. The remaining patient, though not achieving surgical success, had significant reduction of AI to AHI ratio. All patients had subjective improvement in daytime performance. Complications encountered were regarded as minor, including transient nerve injury, minor occlusal change and infection of plates. Conclusion: Maxillomandibular-chin surgical advancement showed a promising treatment outcomes in the management of patients with obstructive sleep apnoea. http://dx.doi.org/10.1016/j.ijom.2017.02.1239 Nitrous oxide laughing matter M. Huston ∗ , J. Ingham, A. Baker School of Medicine, Trinity College Dublin, Ireland Background: We present the case of a young male who presented to the emergency department of our hospital complaining of gross swelling of his right face. He reported no causative history for this presentation. A computed tomography head and neck was completed which revealed significant air emphysema in the soft tissues in the absence of bony trauma. On follow-up examination some days later, the patient disclosed the cause of the incident to be associated with the recreational use of nitrous oxide (N2 O) gas. Discussion: N2 O is increasingly being used as the drug of choice amongst rave and festival goers. It is reported to create a transient sensation of relaxation, euphoria and hallucination amongst users. It is widely available and laws on restriction are difficult to enforce owing to its myriad of commercial and medical uses. In recent

369 years a number of case reports have been published, highlighting complications associated with its illegitimate use. Conclusion: Much study has been completed, investigating the side effects and complications of inhaled N2 O when used in a controlled healthcare setting. This case demonstrates a previously unpublished presentation of emphysema within the facial tissues as a result of its recreational use. Given the increased usage of illicit gaseous drugs, it is likely further complications will present in the future. http://dx.doi.org/10.1016/j.ijom.2017.02.1240 Regeneration of knee meniscus damages by transplanting adipose tissue-derived regenerative cells M. Itose ∗ , T. Suzawa, R. Kamijo, T. Shirota Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Tokyo, Japan Background: Knee meniscus and temporomandibular joint (TMJ) disc are composed of fibrocartilages, lack intrinsic healing capacity following damages due to low vascularisation. Recent reports indicated that adipose tissue-derived regenerative cells (ADRCs) have an ability to regenerate various damaged tissues. Objectives: In this study the regenerative potential of ADRCs on knee meniscus was investigated. Methods: ADRCs were isolated from the inguinal region of Sprague-Dawley rats. We removed the anterior half of the medial meniscus and transplanted the atelocollagen scaffolds with or without ADRCs. ADRCs from green fluorescent protein (GFP)transgenic rats were transplanted into the meniscal defect in nude rats. Chondrogenic, osteogenic differentiation and frequency of ADRCs derived from the inguinal region of rat were also demonstrated. Findings: The area of the regenerated meniscus was appreciably larger in the scaffolds with ADRCs groups than in the scaffolds without ADRCs groups at 12 weeks. In the scaffolds with ADRCs groups, type II collagen expression was clearly observed in areas of regeneration. Using GFP-transgenic rats, we observed that the regeneration of the meniscus resulted from contribution from donor cells of ADRCs. ADRCs had a small fraction of adiposederived stem cells (CD31−/CD34+/CD45−). ADRCs were also able to differentiate into chondrocyte-like and osteoblast-like cells in vitro. Conclusion: ADRCs is useful for regeneration of meniscus tissue. Furthermore, it might become possible to provide novel cell-based therapy for TMJ disc damages by utilising ADRCs for knee meniscus damages. http://dx.doi.org/10.1016/j.ijom.2017.02.1241

Oral syphilis seen at the lateral surface of the tongue: a case report with literature review M. Kumagai ∗ , K. Odashima, N. Kanda, Y. Ezoe Department of Oral and Maxillofacial Surgery, Tohoku Kosai Hospital, Sendai, Japan Background: The incidence of syphilis has been rising worldwide, including in Japan, where the number of registered cases is the highest since the survey by National Institute of Infectious Diseases, Japan began in 1999. Oral manifestations are uncommon and may represent a diagnostic challenge because of its wide spectrum of clinical appearances. Objectives: To cultivate a better understanding of the oral manifestations of syphilis. Methods: A case of secondary syphilis revealed by manifestation at the lateral surface of the tongue was reported. Case reports of oral syphilis in Japan over the past 30 years were reviewed. Finding: A 39-year-old female was referred for diagnosis of soreness of her tongue continuing for approximately one month. On extraoral examination, multiple erythema lesions were observed on her palms. Painlessly swollen cervical lymph nodes with a diameter of 20 mm were felt at both sides of the cervical region. Intraoral examination revealed multiple indeterminately formed slightly raised greyish-white lesions on both sides of the tongue. In serologic tests, fluorescent treponemal antibody absorption (FTAABS) immunoglobulin G resulted positive; rapid plasma reagin (RPR) titer, 1:128 and treponema pallidum haemagglutination (TPHA) 1: 40,960. A diagnosis of secondary syphilis was established. In the Japanese literature, 52 cases were reported from 1986 to 2015. 13 cases were diagnosed as primary syphilis, 30 cases, secondary, 3 cases latent, and 2 cases tertiary. The remaining cases were not documented the disease stage classification. Various manifestations were listed among these reports. Conclusion: Dental surgeons should keep in mind the various manifestations of syphilis in the oral cavity. http://dx.doi.org/10.1016/j.ijom.2017.02.1242 The difficulties of diagnosis of extracranial head and neck schwannomas: two case reports R.L.S. Monteiro ∗ , Y. Deniz, C. Aubert, Y. Vanhemelrijck, M. Shahla, D. Dequanter, P. Lothaire CHU Charleroi, Belgium Background: Schwannomas are benign tumours of the nerve sheath. It is reported that 25–45% of all schwannomas occur in the head and neck region (extracranial). Head and neck schwannomas (HNS) are slow growing and clinical manifestations depend on the tumour location, size and the nerve of origin, but a schwannoma may be found incidentally. Case Reports: We describe two different cases of facial and vagus schwannomas. The first case is an intraparotid schwannoma (IS) in a 57-year-old male complaining of a painless parotid mass mimicking a pleomorphic adenoma according to the ultrasound and magnetic resonance imaging (MRI) findings preoperatively. The second case is a 44-year-old male with a mass in the anterior compartment of the neck. The MRI results showed a tumour located between the carotid artery and the internal jugular vein, suggesting a schwannoma arising from the vagus nerve. Both patients were