Dental Injury Related To Conventional Direct Laryngoscopy

This study aims to investigate especially minor dental traumas and associated damages instead of major traumas that can be directly seen due to conventional laryngoscopy using transillumination technique with cold light source.

After the approval of the Selcuk University Local Institutional Ethics Committee (2017/05), 300 ASA I-III adult patients who underwent elective surgical operations under general anesthesia and underwent endotracheal intubation were included in this prospective, double-blinded study. Written informed consent was obtained from each patient during the preoperative anesthetic evaluation.

During the preoperative anesthetic evaluation, an anesthetist and dentist in the study team performed a detailed oral physical examination on all study patients. Demographic data such as age, gender, body weight, height, data related to airway management such as mallampati score, thromental distance, mouth opening size, and information about past anesthesia history, including previously described difficult intubation and medical condition, were questioned, and recorded. During a dental examination, all teeth, but particularly anterior 6 of maxillary and mandibular teeth, were examined regarding general dental hygiene and the existence of any missing teeth, tooth decay, plaque and stone formation, discoloration, gum problems such as recession and gingivitis, and tooth trauma. The patients with the presence of deformation due to a trauma or a congenital abnormality in the maxilla-fascial region, a swinging tooth, and a history of previous surgical operation regarding the maxilla-fascial region and oral cavity were not included in the study.

All patients were subjected to the same anesthetic process. None of the patients were given anesthetic premedication on the day of surgery. Anesthesia induction was achieved with 2.0 mg.kg-1 iv propofol, 2.0 mg.kg-1 iv fentanyl, and 0.6 mg.kg-1 iv rocuronium after routine monitoring with ECG, non-invasive blood pressure, and SpO2. Each patient was ventilated with a face mask with 100% O2 for 2-3 minutes and intubated with a proper endotracheal tube by the same anesthetist using a conventional laryngoscope. All intubations were achieved by anesthesiologists with different statuses (senior assistants and consultants who were blind to the study). After the endotracheal intubation, the anesthesiologist included in the study recorded the data about intubation and airway management such as Cormack-Lehane Score, laryngoscope blade type and size, difficulty in intubation, use of additional devices such as oral airway, intubating supraglottic airway device, video laryngoscope, and intubating guide in the airway management, and the number of intubating attempts by asking the practitioner.

The intraoperative dental evaluation was performed using a transillumination technique with a cold light source at two different time points: T1: Before anesthesia induction, and T2: After endotracheal intubation, before the start of the surgical operation. The same dentist performed all dental evaluations. Although all teeth were evaluated, the evaluation with the cold light source was particularly for every six teeth in the lower and upper jaws.