Importance Of Mouth Opening Essay

Mouth opening is important because it determines the available space for placing and manipulating laryngoscopes as well as tracheal tubes. A small mouth opening may not accommodate either. Mouth opening also provides room to see through the uppermost part of the airway17. Mouth opening relies on the temporomandibular joint , which works in two ways. It has a hingelike movement and a gliding motion. The gliding motion is known as translation. The hingelike movement allows the mandible to pivot on the maxilla. The more the mandible swings away from the maxilla, the bigger the mouth opening.
The adequacy of mouth opening is often assessed by measuring the inter-incisor distance. An interincisor distance of 3 cm provides sufficient space for intubation, if other complicating factors are absent. This corresponds approximately to two finger breadths. The two finger breadth test is performed by placing the examiner 's

The base of tongue resides close to the glottic aperture. During traditional direct laryngoscopy, the base of tongue falls posteriorly, obstructing the line of sight into the glottis. Visualizing the larynx requires displacing the base of tongue anteriorly so that the line of sight to the glottis is restored. The tongue is frequently displaced with a hand-held rigid laryngoscope, to which Macintosh and Miller blades are most commonly attached. These laryngoscopes push the tongue anteriorly and, in so doing, move it from a posterior obstructing position to a new anterior nonobstructing position. The new position is within the mandibular space. The mandibular space is the area between the two rami of the mandible. Even with the tongue maximally displaced into the mandibular space, visualization of the larynx is sometimes inadequate. A tongue which is large compared with the size of the mouth (oropharynx) and mandible takes up excessive space in the oropharynx and thus interferes with