Review question
With this Cochrane Review we tried to find out the best way to manage gagging in people having dental treatment.
Background
The gag reflex is a normal process to protect the throat and airway from foreign objects and prevent choking. Many people have an exaggerated gag reflex that causes distress during dental treatment. This can make it difficult or even impossible to perform the treatment. The interventions used to manage gagging include anti-nausea medicines, sedatives, local and general anaesthetics, herbal remedies, behaviour therapy and cognitive behaviour therapy, acupressure, acupuncture, laser, and prosthetic devices.
We wanted to know how effective and safe these interventions are in helping people complete their dental treatment with less gagging. We compared them to no intervention or a placebo or to other interventions.
Study characteristics
This review is up-to-date as of 18 March 2019. We included four trials with 328 people (263 adults and 65 children who were 4 years or older). These people had nausea before when having dental treatment that caused the treatment to be stopped or not carried out properly.
Key results
Acupuncture at P6 point (a point located in the inside of the wrist) showed uncertain evidence regarding the successful completion of dental treatment and reduction in gagging when compared to sham (fake) acupuncture. The same intervention with sedation did not show a difference.
Acupressure (with thumb or sea band (bands that fit around the wrist just like a sweat band with a pressure stud sewn inside)) at P6 point with or without sedation did not show any difference when compared to sham acupressure. Acupressure at P6 point with device showed a difference in completing dental treatment and reduction in gagging. It did not show a difference when combined with sedation.
Laser at P6 point showed a difference in absence of gagging and reduction in gagging during dental treatment when compared to sham laser application.
The included studies did not report any important harmful effects of the treatment.
Certainty of the evidence
The level of belief we have in these findings is very low. This was due to unclear risk of bias and the small number of people studied in the four included trials.
Conclusion
We do not have enough evidence to say which intervention works better to manage gagging in people having dental treatment. We suggest that more well-conducted studies should be done in this area.
We found very low-certainty evidence from four trials that was insufficient to conclude if there is any benefit of acupuncture, acupressure or laser at P6 point in reducing gagging and allowing successful completion of dental procedures. We did not find any evidence on any other interventions for managing the gag reflex during dental treatment. More well-designed and well-reported trials evaluating different interventions are needed.
The gag reflex is an involuntary defence mechanism to protect the pharynx and throat from foreign objects. Gagging is a common problem encountered during dental treatment, making therapeutic procedures distressing and often difficult or even impossible to perform. Various interventions can be used to control the gag reflex: anti-nausea medicines, sedatives, local and general anaesthetics, herbal remedies, behavioural therapies, acupressure, acupuncture, laser, and prosthetic devices. This is an update of the Cochrane Review first published in 2015.
To assess the effects of pharmacological and non-pharmacological interventions for the management of gagging in people undergoing dental treatment.
Cochrane Oral Health's Information Specialist searched the Cochrane Oral Health's Trials Register (to 18 March 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2) in the Cochrane Library (searched 18 March 2019), MEDLINE Ovid (1946 to 18 March 2019), Embase Ovid (1980 to 18 March 2019), CINAHL EBSCO (1937 to 18 March 2019), AMED Ovid (1985 to 18 March 2019), and the proceedings of the International Association for Dental Research (IADR) online (2001 to 18 March 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. We also conducted forwards citation searching on the included studies via Google Scholar. No restrictions were placed on the language or date of publication when searching the electronic databases.
We included randomised controlled trials (RCTs), involving people who were given a pharmacological or non-pharmacological intervention to manage gagging that interfered with dental treatment. We excluded quasi-RCTs. We excluded trials with participants who had central or peripheral nervous system disorders, who had oral lesions or were on systemic medications that might affect the gag sensation, or had undergone surgery which might alter anatomy permanently.
We independently selected trials, extracted data, and assessed risk of bias. We followed Cochrane's statistical guidelines. We assessed the overall certainty of the evidence using GRADE.
We included four trials at unclear risk of bias with 328 participants (263 adults and 65 children who were four years or older), in which one trial compared acupuncture and acupressure (with thumb, device and sea band) at P6 (point located three-finger breadths below the wrist on the inner forearm in between the two tendons) to sham acupuncture and acupressure with and without sedation. One trial compared acupuncture at P6 point to sham acupuncture. These trials reported both completion of dental procedure and reduction in gagging (assessor and patient reported) as their outcomes. One cross-over and one split-mouth trial studied the effect of laser at P6 point compared to control. One trial reported reduction in gagging and another reported presence or absence of gagging during dental procedure.
Acupuncture at P6 showed uncertain evidence regarding the successful completion of dental procedure (RR 1.78, 95% CI 1.05 to 3.01; two trials, 59 participants; very low-certainty evidence) and uncertain evidence regarding the reduction in gagging (RR 2.57, 95% CI 1.12 to 5.89; one trial, 26 participants; very low-certainty evidence) in comparison to sham acupuncture. Acupuncture at P6 with sedation did not show any difference when compared to sham acupuncture with sedation (RR 1.08, 95% CI 0.91 to 1.28; one trial, 34 participants; very low-certainty evidence).
Acupressure using thumb pressure with or without sedation showed no clear difference in completing dental procedure (RR 0.96, 95% CI 0.84 to 1.10; one trial, 39 participants; very low-certainty evidence; and RR 0.85, 95% CI 0.50 to 1.46; one trial, 30 participants; very low-certainty evidence; respectively), or reduction in gagging (RR 1.06, 95% CI 0.92 to 1.23; one trial, 39 participants; very low-certainty evidence; and RR 0.92, 95% CI 0.60 to 1.41; one trial, 30 participants; very low-certainty evidence; respectively) when compared to sham acupressure with or without sedation.
Acupressure at P6 with device showed uncertain evidence regarding the successful completion of dental procedure (RR 2.63, 95% CI 1.33 to 5.18; one trial, 34 participants; very low-certainty evidence) and uncertain evidence regarding the reduction in gagging (RR 3.94, 95% CI 1.63 to 9.53; one trial, 34 participants; very low-certainty evidence) when compared to sham acupressure. However, device combined with sedation showed no difference for either outcome (RR 1.16, 95% CI 0.90 to 1.48; one trial, 27 participants; very low-certainty evidence; and RR 1.26, 95% CI 0.93 to 1.69; one trial, 27 participants; very low-certainty evidence; respectively).
Acupressure using a sea band with or without sedation showed no clear difference in completing dental procedure (RR 0.88, 95% CI 0.67 to 1.17; one trial, 21 participants; very low-certainty evidence; and RR 1.80, 95% CI 0.63 to 5.16; one trial, 19 participants; very low-certainty evidence; respectively), or reduction in gagging (RR 0.88, 95% CI 0.67 to 1.17; one trial, 21 participants; very low-certainty evidence; and RR 2.70, 95% CI 0.72 to 10.14; one trial, 19 participants; very low-certainty evidence; respectively) when compared to sham acupressure with or without sedation.
Laser at P6 showed a difference in absence of gagging (odds ratio (OR) 86.33, 95% CI 29.41 to 253.45; one trial, 40 participants; very low-certainty evidence) and reduction in gagging (MD 1.80, 95% CI 1.53 to 2.07; one trial, 25 participants; very low-certainty evidence) during dental procedure when compared to dummy laser application.
No noteworthy adverse effects were reported. For acupuncture at P6, the trial authors were unsure whether the reported adverse effects were due to participant anxiety or due to the intervention. None of the trials on acupressure or laser reported on this outcome.
We did not find trials evaluating any other interventions used to manage gagging in people undergoing dental treatment.