NMDA Journal Spring 2016

The following seven intrinsic reflexes, often seen as a disruption or obstacle to completing dental care, are actu-

ally hard-wired defensive responses the body uses for protection. One or all of these mechanisms may be a reason for a

patient’s reluctance to seek general dental care and their declining poor dental health. While the following physiological

actions can be executed voluntarily, the functional actions resulting from reflex initiation is involuntary and it is these

autonomic actions that are considered in this article.

#1 Gag Reflex

The Gag Reflex is a common reason patients seek deeper

levels of sedation for dentistry. The Gag Reflex halts

swallowing to prevent intrusion of foreign materials,

substances, or large food stuffs from entering the trachea,

pharynx or larynx and prompt choking. This reflex is acti-

vated when an unwelcome object touches the soft palate

in the mouth, posterior one third of the tongue, tonsillar

and surrounding tissues, or the oropharynx. Neurons

that innervate the nucleus tractus solitarii (NTS) in the

medulla oblongata are responsible for the activation of

motor/sensory cranial nerve IX (glossopharyngeal n.),

along accessory nerves to begin the tongue’s downward

positioning and forward thrusting action in preparation

to launch the unwanted material.

Though closely related

to the Laryngospastic Reflex covered in a later section,

the rapid vocal cord closure, or laryngospam, in the Gag

Reflex differs in that it is not exaggerated or prolonged,

only lasting as long as is needed to expel the invading

material and usually associated with fully awake, non-

sedated patients. For patients undergoing procedures in

or around the airway, oral cavity structures, soft palate,

posterior tongue, such as dental procedures, aerosol

delivery of 4% lidocaine given during quite breathing

prior to stimulation has been shown to abolish the gag

reflex for 15 to 20 mins.

Tried management techniques for the Gag Reflex during

dental procedures have ranged from hypnosis to deep

levels of anesthesia. Literature reviews show dentists using

acupuncture, Listerine swish and swallow techniques, and

while moderate success can be obtained, two methods

have stood out as effective management techniques. One,

deep levels of sedation/general anesthesia and behavior

modification. Deep levels of anesthesia/general anesthesia

(DS/GA) by a trained dental anesthesia provider is an

effective means due to the fact that the patient is chemi-

cally, but safely brought into a decreased responsive state,

thereby, decreasing the responsiveness to the nerve stimu-

lation needed to initiate the gagging motion. Deep seda-

tion/general anesthesia is most beneficial with patients

that have a severe or highly disruptive gag reflex. DS/

GA is quick to administer and most dental work can be

completed in one visit.

For those providers that do not have access to a dental

anesthesiologist, one of the more widely useful techniques

is behavior modification. While deep sedation/general

anesthesia can be a short-term solution, behavior modi-

fication can be a long-term solution and is most useful

for slight to moderate gaggers. Behavior modification is

based off the fact that the act of gagging is multifactorial

and controlling triggers, such as sight or smell of equip-

ment or materials, is controlled and adapted. Behavior

modification attempts to identify the dental trigger event

and adapt the five anatomical intraoral areas, known to be

“trigger zones”: palatoglossal and palatopharyngeal folds,

base of tongue, palate, uvula, and posterior pharyngeal

wall to accept pressure from dental manipulation.

The

drawback to successful behavior modification is that

dental treatment must now be performed over a number

of office visits with reinforcement of the acclimatizing

technique at each appointment.

# 2 Cough Reflex

As with the Gag Ref lex, the NTS nerve clusters in

the medulla also facilitate the Cough Reflex, but with

increased neuronal transmission involvement from the

continues



By Jason R. Flores, RN, DDS, DADBA, DNDBA, FADSA