In this randomized crossover trial the investigators test whether three different brands of videolaryngoscopes (VLS) exhibit reduced forces on both upper and lower teeth, and compare them with a classic Macintosh laryngoscope blade.

During endotracheal intubation the anesthesiologist uses a laryngoscope blade to distract the tongue to achieve the best view of the glottis opening, thereby avoiding using the maxillary incisors as a fulcrum to lever the soft tissues upwards. Using the maxillary incisors as a fulcrum may otherwise result in dental trauma. It is obvious that contact with teeth and - even worse - the incidence of accidental dental trauma, is directly related to the difficulty of the intubation.

Indirect videolaryngoscopy has proven advantageous over direct laryngoscopy using a classic Macintosh blade, for improved viewing of the glottis, with subsequent more successful intubations, and a shorter effective airway time both in patients with normal and difficult airways. Previously, it has been demonstrated that the forces exerted by the anesthesiologist on the patient's maxillary incisors are reduced when using a VLS, compared with a classic Macintosh laryngoscope. However, only one type of VLS (V-MAC®, Karl Storz, Tuttlingen, Germany) was used or only forces applied to upper teeth were being registered.

Inclusion Criteria:

• Informed patient consent
• ASA I -III
• Age > 18 years
• Elective surgery, other than head and/or throat surgery
• Pre-operative Mallampati I -III
• Fasted (≥6 hours)

Exclusion Criteria:

• No informed patient consent
• ASA ≥ IV
• Age < 18 year
• Emergency surgery, surgery of head and/of throat
• Locoregional anaesthesia
• Pre-operative Mallampati IV
• Fasted < 6 hours
• Pre-operative expected difficult airway
• No teeth, bad dentition
• Dental crowns and/or fixed partial denture