Forces on Teeth During Videolaryngoscopy

Forces Exerted on Upper and Lower Teeth During Intubation: a Randomized, Cross-over Trial Comparing Indirect Videolaryngoscopy to Direct Videolaryngoscopy.

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01599312

Enrollment

100

Registered

2012-05-16

Start date

2012-05-31

Completion date

2012-09-30

Last updated

2015-02-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Intubation Complication, Tooth Injuries

Keywords

Videolaryngoscopy, Forces, Teeth

Brief summary

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.

Detailed description

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.

Interventions

DEVICEForces exerted on teeth during intubation

Anesthesia will be induced in the conventional matter. The classic Macintosh laryngoscope will be placed in the patient's mouth and a tube will be brought into position in front of the glottis. Hereafter, one of the three videolaryngoscopes will be placed in the patient's mouth and the endotracheal tube will be actually passed through the vocal cords. The measurement of forces applied to the teeth will be performed using Flexiforce® sensors.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

PREVENTION

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
Measuring the frequency with which forces are applied to the upper and lower teeth.	At intubation of the patient	One of the three videolaryngoscopes will be placed in the patient's mouth. The measurement of forces applied to the teeth will be performed using Flexiforce® sensors.

Secondary

Measure	Time frame
Measuring the magnitude of the forces being applied and registering the differences between (video)laryngoscopes.	At intubation of the patient

Countries

Netherlands

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026