title: Forces applied to the maxillary incisors during tracheal intubation and dental injury risks of intubation by beginners: a manikin study.
abstract: OBJECTIVE
  We wished to determine whether dental injuries during intubation would occur more frequently when performed by inexperienced beginners. We measured the laryngoscopic force exerted on maxillary teeth of a modified manikin by experienced anesthesiologists and unexperienced medical students and estimated the injury risk.
  
  
  METHODS
  Thirty-two anesthesiologists and 32 medical students participated in this study. Each testee performed tracheal intubation in two scenarios in a random order. In Scenario 1, the testee performed tracheal intubation for a manikin as a patient with normal dentition, in an emergency type situation. In Scenario 2, the testee performed tracheal intubation for a manikin as a patient with unstable dentition, in a routine anesthetic situation.
  
  
  RESULTS
  The mean peak forces in Scenarios 1 and 2 were 6.1 and 1.1 N in the experienced testee group and 7.7 and 3.8 N in the unexperienced testee group, respectively (Scenario 2, p < 0.05). The unexperienced group applied higher forces than the experienced group in the nonemergency situation. However, the maximum force applied by the inexperienced group was 40.2 N, which is substantially lower than the maximum bite force of normal incisors (150-200 N).
  
  
  CONCLUSIONS
  Our results suggest that the experience levels of the laryngoscopists are not a major determinant of dental injuries in patients with healthy dentition.
authors: Department of Anesthesiology, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, Tsukuba University, Tsukuba, Ibaraki, Japan. taekof@md.tsukuba.ac.jp
authors: Taeko
authors: T
authors: Fukuda
authors: Yuri
authors: Y
authors: Sugimoto
authors: Soichiro
authors: S
authors: Yamashita
authors: Hidenori
authors: H
authors: Toyooka
authors: Makoto
authors: M
authors: Tanaka
mesh_terms: D000776:Anesthesiology / Q000193:education*; D006801:Humans; D007180:Incisor / Q000293:injuries*; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D007828:Laryngoscopy; D008348:Manikins; D008437:Maxilla; D013337:Students, Medical