Dental injury in general anesthesia: a comparison between direct laryngoscopy and McGRATH® VLS.

Abstract INTRODUCTION Dental injury occurs in 0.06 - 0.13 % of general anesthesia procedures requiring endotracheal intubation, and it is still a reason of complaint against anesthesiologists. Maxillary central incisors are the most common teeth injured. OBJECTIVES: The aim of this study is to measure the forces applied on teeth using a direct laryngoscope or a McGRATH® video-laryngoscope. MATERIALS AND METHODS: 39 Anesthesiologists were divided into 2 groups, one of experienced anesthesiologists and the other of residents enrolled in the anesthesiology residency program of “Città della Salute e della Scienza” of Turin. Six intubations each were performed on a training manikin; three intubations using the standard intubation system with a traditional laryngoscope, and the other three using the McGRATH® video-laryngoscope in order to test the intubation forces exerted. A force sensor (Tekscan Flexiforce® ELF system) was applied under a customized dental bite made for maintaining the pressure sensor in the correct position. This customized device was handcrafted on the dental impression of the manikin teeth in order to register any type of pressure reported on the incisal margin of the manikin`s central incisors. The forces applied were translated and measured thanks to a force acquisition system (ELF System) for real-time force measurement data acquisition. RESULTS: Between February 2017 and May 2017, 39 anesthesiologists were enrolled in the study. The median age was 42 (IQR 31-53).70% were experienced anesthesiologists. There was statistically significant reduction of the forces directly applied to the maxillary incisors using the McGRATH® VLS, compared with the classic McGill blade (reduction of 11.44 Newton, 95%CI -14.33; -8.55, p >0.0001) CONCLUSION: The use of the McGRATH® VLS during endotracheal intubation can be useful to reduce/prevent tooth damage. In the pre-anesthesiologist visit there are certain categories of patient who have to be visited by a dentist before oro-tracheal intubation(OTI). In these categories of selected patients, the use of the McGRATH®VLS can be a viable treatment option.