Factors Affecting Gagging and its Management in Prosthodontic Patients: A Review

ABSTRACT

Gagging is a protective reflex to guard the upper respiratory tract and the digestive tract from foreign body obstruction. When this reflex becomes abnormally active, compromise in the quality of dental treatment is observed. The selection of effective management techniques depends on causes and factors affecting gagging. The article aims to review the nature, factors, neurophysiology, different treatment modalities of gagging so that clinicians include strategies and utilize flexible approaches in dealing with this gag reflex.

Keywords- Gagging, vomiting, acupressure.

INTRODUCTION

Gagging is protective reflex for airway protection and removal of irritant material from posterior oropharynx and GIT.¹ According to GPT-8: Gag is an involuntary contraction of the muscles of the soft palate or pharynx that results in retching. When respiratory muscles undergo spasmodic contraction during retching, air is forced through the closed glottis, because of which retching sound is produced. Along with, chest muscles are in fixation and thoracic inlet muscles are contracting resulting in impediment of the venous return, dilation of the veins of the head and neck, flushing and congestion of the face. Embarrassment in patients and compromised dental treatment are major cause of concern for a dentist. For effective management of gagging patients, the dentist should determine all possible factors (anatomic, organic, psychological) and causes of this active gag reflex.

Classification of Gagging

• Faigenblum classified patients into mild and severe retching patients. The patients with mild retching experiences nausea with minimal reaction to a stimulus but are generally able to able to control their reflex. The patients with severe retching respond in an exaggerated manner to physical or psychological stimuli and are unable to tolerate impressions, operative procedures, or insertion of new or old dentures, radiographs.³
• Morstad classified gagging reflex into immediate and delayed. The immediate gagging reflex occurs immediately after the prosthesis is given to the patient. It is caused by overextension at post palatal area in maxillary denture or bulky distolingual flange in mandibular denture. Whereas the Delayed gagging reflex occurs within two weeks to two months after insertion of the denture. It may be due to an incomplete border seal which allows seepage of saliva under the denture.
• Davis classified gagging as either somatogenic or psychogenic. The somatogenic gagging is induced by physical stimuli. The five intra-oral areas ‘trigger zones’ for physical stimuli are palatoglossal and palatopharyngeal folds, base of tongue, palate, uvula, and posterior pharyngeal wall.⁴ The psychogenic gagging is induced by psychological stimuli like anxiety, fear and apprehension.¹

Neurophysiology of gagging and its clinical description

As the tactile stimulation of soft palate or posterior third of tongue occurs, afferent impulses are transmitted to the center in medulla oblongata. Following that efferent impulses are transmitted from the center of medulla oblongata resulting in spasmodic and uncoordinated movements of gagging.

The clinical description of the events during gagging is explained as:

Initially puckering of lips is observed and patient tries to close the jaws. Followed by elevation and furrowing of the tongue and elevation of soft palate and hyoid bone. Once the hyoid bone is fixed, nasopharynx gets closed. Tonsils rotates anteromedially due to contraction of faucial pillars followed by elevation, contraction and retraction of the larynx and closure of glottis. Retching or simultaneous and uncoordinated respiratory muscle spasm is observed and hence vomiting.

Factors affecting gagging

a). Local and systemic disorders:

Diaphragmatic hernia, uncontrolled diabetes and conditions like nasal obstruction, postnasal drip, sinusitis, nasal polyps, congestion of the oral, nasal and pharyngeal mucosa can increase gagging.⁵ Chronic diseases of gastrointestinal tract like chronic gastritis, peptic ulcers, carcinoma of stomach, partial gastrectomy, cholecystitis results in increased irritability and decreased threshold for excitation of oral cavity.⁶

b). Anatomical factors:

Gag reflex can be due to factors like anatomic abnormalities and oro-pharyngeal sensitivities.^7,8 In a study of denture wearers, no anatomic anomaly was observed when radiologic anatomy of gagging and non-gagging patients was compared. Though enlarged areas of sensory innervation were observed, but it couldn’t explain why patients gag with auditory, olfactory, or visual stimuli.⁹

c). Social factors of gagging: Heavy smoking and drinking can result in inflammation of pharynx and hence hypersensitive gag reflex.

d). Physiologic Factors: These can be extra oral/non tactile and intraoral/tactile stimuli.

EXTRAORAL STIMULI:

Factors like visual, auditory and objector stimuli (odour of smoke of cigarette, dental materials and clinic) can predispose to gagging. Landa describes how gag reflex precipitated in a patient due to acoustic stimulus of his gagging wife in another operatory.¹⁰

INTRAORAL STIMULI:

Tactile (Intraoral) stimulation is present while execution of dental procedures. According to Landa, most sensitive regions in oral cavity are posterior part of palate and upper surface of the posterior one third of the tongue.¹⁰ According to the dental literature the biomechanical considerations like inadequate post dam, freeway space, retention, over extended posterior borders may result in gag reflex.^11,12 Movement of the prostheses due to these considerations stimulates tickling sensation and contributes to gagging. Krol explained how inadequate freeway space can elicit a gag reflex. If vertical dimension exceeds the rest vertical dimension, As the spasm of tensor palatini muscles occurs, tactile sensation is produced. Due to this sensation, maxillary denture extends too bar backward, pressing against the posterior border of the denture, predisposing to gag reflex.¹

e). Iatrogenic Factors: Iatrogenic factors like incorrect occlusion, poor retention, surface finish of denture can affect reflex of gagging. Landa explained that by correction of occlusion and using balanced articulation, gag reflex can be managed.¹⁰

GAGGING SCORES

Dickinson & Fiske gave the gagging severity index¹³

MANAGEMENT

Clinician has to obtain a detailed history in a comfortable and reassuring environment. After the intraoral examination, the consent is taken to proceed with the treatment plan. The role of the clinician is to be sympathetic to the patient’s difficulties and to allow the patient to receive dental care with a minimum of anxiety and stress.^1,14,15 Effective management depends on the factors and causes and not only on the symptoms of the gagging patients fall into the following categories:

1. Psychologic intervention
2. Prosthodontic management
3. Pharmacologic measures
4. Surgical intervention
5. Accupressure and Accupunture.

1). Psychologic intervention:

Psychotherapy includes hypnosis, behavior management procedure of systemic desensitizing, covert reinforcement modelling fear reduction. Relaxation helps to rule out the awkward thought processes. Patient is asked to tense and relax certain muscle groups, starting with the legs and working upwards. This relaxes the patient and thus helps him/her to adapt to the clinical procedures ahead.

Distraction techniques can be used for short dental procedure by diverting patient’s attention. Landa suggested engagement in other topics of patient’s interest for distraction.¹⁰ Kovats suggested a technique by which patient simultaneously breathes audibly through nose and taps the right foot on the floor.¹⁶ Faigenblum stated that by simply talking to patient clinician can distract the patient to carry out the clinical procedures.³ Krol asked the patient to raise one of their leg and told him/her to concentrate on keeping the leg in the same position for the duration of impression procedure. This will help the patient to prevent the episode of gag reflex by distraction from clinical procedure.¹ Robb explained the use of two suggestion/distraction technique. Firstly the ‘sick stick’ on which patient is asked to focus during impression procedure. Secondly in ‘temporal tap’ technique, dentist taps the temporo-parietal suture for distracting the patient from the clinical procedure. Some dentists use virtual reality goggles, chair mounted television and music therapy as an aid to manage the anxiety of the patients by distraction.

‘Controlled rhythmic breathing’ was the method used by Hoad-Reddick to overcome gag reflex.¹⁵ Barsby suggested to encourage ‘relaxed abdominal breathing’.

Hypnosis is one of the management approaches for the patients with gagging. Barbsy stated that hypnosis is not itself a therapy but means of facilitating a particular treatment strategy. Hypnotherapy is the treatment of disease by hypnosis. But due to lengthy and multiple interviews it is not used by many dentists.¹⁷ Desensitization Technique provides with permanent effects in contrast to temporary solutions by the distraction techniques. Wilks used a number of successful methods of desensitization, namely habituation and de-conditioning. These include stroking the tip of the tongue repeatedly; asking patient to hold small buttons under tongue, roll them around the mouth and instructed about the method of swallowing keeping teeth apart. The patient is asked to repeat the procedure as homework. The Cognitive Therapy emphasizes on change of irrational thought processes.¹⁸ For example, in some patients retching is observed during use of high-speed handpiece due to fear of choking and breathlessness. Acognitive behavioral psychotherapist tries to rationalize these thought patterns to prevent gagging.

2). Prosthodontic management:

It involves certain modifications of the prosthesis for better acceptance in the patients. Before making any radical modifications in the prosthesis, overextension, excess thickness or inadequate postdam of the prosthesis should be corrected. Jordan suggested that smooth, glossy surface was less acceptable than matte finish is more acceptable to patients than a glossy surface.¹⁶ Krol explained the importance of "Freeway" space. He evaluated serious gagging problems in100 patients due to inadequate freeway space which was resolved by an increase in the interocclusal distance.¹

Borkin advocated the use of intraoral wax, which being thermoplastic could be used to obtain the final impression in gagging patients.¹⁹

Singer’s marble technique was reported as one of the effective approaches for complete denture gagging patients. At the first appointment, the patient was asked to place five marbles in his mouth one at a time and at his leisure. On the day of second appointment, patient is advised to keep the marbles for 1 week except for eating and sleeping. At the third visit modeling compound impression were made, refined and completed. At the fourth visit, the lower base tray was inserted along with three marbles in the mouth, and a "training bead" was placed on the lingual aspect of the base tray to maintain proper tongue position. During the fifth visit, patient was advised to discontinue the use of marbles. On sixth visit, jaw records were made and the occlusion rims marked. The completed dentures were inserted at the seventh visit and patients were motivated to use the prosthesis.²⁰

Modification of edentulous maxillary custom tray

In this technique second layer of autopolymerising tray acrylic is added to original custom tray. Removal of wax spacer is done to aid in removal of excess impression material as it extrudes from the posterior border of the maxillary custom tray before it can elicit a gag reflex in the patient.^21,22

Denture modifications

Palateless denture, Nickel chrome alloy or aluminium cast metal denture base are the possible modifications to prevent gag reflex.^23,24 The advantage of such metal base denture is increased rigidity, retention thereby providing a stable base for recording of jaw relations.^25,26 Bay recommended shape modification of denture base in combination with overdenture principle for excellent retention and management of the gag reflex.²⁷ Use of neutral zone principle for construction of the hollow obturators also prevented gagging in patients.^28,29

3). Pharmacologic measures:

After psychologic and prosthodontic measures, pharmacologic measures are considered as possible way to manage gagging patients. These can be classified as peripherally acting or centrally acting.

Peripherally acting drugs

These drugs are topical and local anesthetics. They may be applied in the form of sprays, gels, or lozenges or by injection. Topical anesthetics used include topical benzocaine 14% and tetracaine hydrochloride 2%. These are effective only for minor gagging. These drugs eliminate afferent impulses from sensitive oral tissues, hence prevents gagging. These drugs don’t provide long term solution.³⁰ Kovats successfully made the maxillary impression by using topical anesthetic spray over the hard palate.³¹ Schole observed that “Topical anesthetics may actually increase nausea and vomiting because the and pharyngeal areas may be sufficient to excite the vomiting reflex”.³² Landa objected to the use of an injectable local anesthesia as it can initiate gag reflex and may distend the tissues, which results in compromised retention.¹⁰ Appleby and Day reported that the use of common table salt on the tongue or on the palate may prevent gagging in complete denture patients.³³

Centrally acting drugs

These drugs are categorized as antihistamines, sedatives and tranquilizers, parasympatholytics, and central nervous system depressants. Pharmacologic intervention offers only a short-term solution, especially for severe, chronic problems.

Kramer and Braham recommended the intramuscular injection of Phenergan (for its strong antihistaminic, antisalivary and antiemetic effect) and Nisentil (for its sedative effect) in gag reflex patients.³⁰

4). Surgical Techniques:

Leslie et al described a surgical technique for shortening and tightening of soft palate in patients who were unable to tolerate dentures because of gagging. In patients with atonic and relaxed soft palates, the palate will be in an abnormal relation with the uvula and pharyngeal wall which produces a tendency for gagging.³⁴ But this technique is not acceptable nowadays.

5). Accupuncture and Accupressure:

Acupuncture is a system of medicine in which a one, fine, single-use disposable needle of 7mm in length is inserted into the anti-gagging point of each ear to depth of 3mm. The needle is manipulated for 30 seconds prior to dental treatment and it remains in situ while the dental procedure. Needle is removed just before the patient is discharged. This technique is said to be safe, quick, inexpensive and relatively non-invasive.

Accupressure technique has been described as effective in controlling gag reflex during dental procedures. Chengjiang (REN-24), an effective acupressure point, is located in the horizontal mento-labial groove, approximately midway between the chin and the lower lip. In this technique light finger pressure is applied with the index finger until the patient feels discomfort. This procedure should start at least 5 minutes before impression making and should continue throughout. It should be terminated only after the removal of impression from patient’s mouth.^35,36,37

SUMMARY AND CONCLUSION

The most serious problem associated with the gag reflex is the strong potential for compromised treatment and the complications associated with treatment. To manage the problem of gagging clinician requires knowledge and experience of all the management techniques. No single technique is sufficient to manage gagging problem, so a thorough examination, detailed history and diagnosis for selection of technique may help to overt this gag reflex.

REFERENCES