NMDA Journal Spring 2016

Swallowing in the dental setting is usually not troublesome

and is easily managed. However, in the event a patient has

disordered swallowing, the movement is usually elicited

with oral stimulation. Disordered swallowing is most seen

in patients with special needs and can be a disruption.

Management can be achieved through DS/GA with a very

experienced provider to achieve levels deep enough to

abolish the reflex. Non-pharmacological management can

be achieved with the aid of physical devices, such as bite

blocks or oral molts, high Fowler’s (beach) position (head

of the chair raised 30 to 90 degrees) of the dental chair,

reducing the force on the base of the tongue during retrac-

tion, and attentive suctioning of oral secretions.

#6 Vomit reflex

Like the Laryngospastic Ref lex, the Vomit Ref lex is

characteristically violent in nature. An expulsive force is

used to quickly move noxious material away from airway

structures or from damaging gastric mucosa. Vomiting, or

regurgitation, can be voluntary or involuntary depending

on a patient’s medical conditions. The involuntary reac-

tion will be discussed in this article. The Vomit Reflex can

be viewed as an extended consequence of Gag or Cough

Reflex failure or hyperactivity of both reflexes. As an

unwanted intrusion escapes past the first two reflexes, it

is either immediately expulsed along with gastric contents

or enters the esophagus via swallow reflex actions where

is expulsed along with gastric contents. The Vomit Reflex

begins with diaphragmatic contractions and progresses

rapidly to laryngeal elevation and distention in prepara-

tion to clear a path for the vomitus. As the larynx clears

a path, the pharyngeal muscles intrinsically relax to allow

the regurgitant 2 – 3 seconds of unimpeded reverse peri-

staltic flow out of the oral cavity.

Completion of the

vomit cycle ends as strong esophageal, hyoid, and supra-

hyoid muscle contractions subside and the patient resumes

a normal breathing pattern. As aid to the Vomit Reflex’s

actions, external abdominal muscles often contract to

help patients achieve an optimal position for regurgitant

expulsion.

In most cases the Vomit Reflex closely follows the Gag

Reflex, so managing vomiting means limiting gagging.

Physiologically, vomiting is primarily activated with aggres-

sive stimulation of the phrenic (CN3 – 5), vagal (X), and

accessory sympathetic nerves and is a reflex innate at

birth, but has the capacity for modification of intensity

and trigger.

In patients with special needs, the Vomiting

Reflex can be a defense mechanism to ward off dentists.

These patients need special care to acclimate to the dental

environment and providers. If a patient begins to vomit

in the dental setting, providers may need to help sit the

patient forward and lean them over to optimize the

reflex and allow gravity or dental suction devices to aid

in ensuring that during the first recovery breath, aspira-

tion does not occur.

#7 Esophagoglottal Closure reflex

This last ref lex is the most recent protective ref lex

being studied and is thought to play a role in preventing

refluxed stomach contents from damaging the airway.

The Esophagoglottal Closure Reflex (ECR) is elicited

during the proximal esophageal distention that occurs

during reflux events. As the name implies, a proximal

esophageal distention of 10-60 ml volume causes closure

of the glottal opening (vocal cords) to prevent aspiration

of gastric contents. Larger volumes cause concurrent

upper esophageal sphincter (UES) dilation and belching

along with glottal anterior movement to sweep materials

away from the glottal opening. These larger volumes of

refluxate cause anterior movement of the hyoid bone

which in turn recruits a wider range of tongue, pharyn-

geal, and laryngeal movements to move refluxate up and

away from the respiratory opening. While proximal esoph-

ageal distention has a direct relationship and activation of

glottal closure, UES dilation to initiate a belching event

does not directly activate glottal closure.

Esophagoglottal Closure Reflex (ECR) should not be

confused with gastroesophageal reflux disease (GERD).

GERD is the medical condition resulting from an abnor-

mally weakened lower esophageal sphincter (LES) that

results in chronic mucosal damage to the esophagus

due to escaping stomach contents. Whereas, ECR is a

normal physiological means of the airway protecting itself

when refluxed contents are detected. They are related in

that when GERD is occurring, then ECR will initiate

to protect the subglottal portions of the airway. Manage-

ment of the dentition for patients with GERD will not

be addressed in this publication. Focus for management

will be of the reflex mechanism during dental procedures.

ECR may result in a transitory cessation of breathing or

forceful coughing, may involve vomitus expelled into the

oral cavity during technique sensitive dental procedures,

and may result in patient expressing retrosternal burning

pain during the reflux episode.

Management starts with

a good medical history to determine a patient’s likelihood

of reflux occurrence, elevation of the dental chair into

New Mexico Dental Journal, Spring 2016