Management of gag reflex for patients undergoing dental treatment

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, which makes therapeutic procedures distressing and often difficult or even impossible to perform. Various interventions can be used to control the gag reflex; for example, anti-nausea medicines, sedatives, local and general anaesthetics, herbal remedies, behavioural therapies, acupressure, acupuncture, and prosthetic devices.

To assess the effects of pharmacological and non-pharmacological interventions for the management of gagging in people undergoing dental treatment.

We searched the Cochrane Oral Health Group's Trials Register (to 7 April 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 4, 2014), MEDLINE via OVID (1946 to 7 April 2015), EMBASE via OVID (1980 to 7 April 2015), CINAHL via EBSCO (1980 to 7 April 2015), AMED via OVID (1985 to 7 April 2015), IADR Conference Proceedings (online, 2001 to 7 April 2015), clinical trial registries and Google search engine.

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 and cross-over trials. 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.

Two review authors independently selected trials. Three review authors independently extracted data and assessed risk of bias in the included trials. We estimated risk ratios (RRs) for dichotomous data, and mean differences (MDs) for continuous data, with 95% confidence intervals (CIs). We assessed the overall quality of the evidence using the GRADE approach.

One RCT, a trial on acupuncture at P6 (Pericardium 6 - situated on the anterior surface of wrist), met the inclusion criteria. It included 33 adults who reported previous nausea during dental procedures that hindered or prevented dental treatment from being carried out properly. The trial was at unclear risk of bias. The outcome reported in this trial was reduction in gagging. We obtained data for our primary outcome (successful completion of dental procedure) by contacting the trial author.Successful completion of dental procedure reported by the assessor showed no difference in acupuncture at P6 group compared to sham acupuncture (RR 1.65, 95% CI 0.59 to 4.57). Reduction in gagging as reported by the assessor showed no difference between acupuncture at P6 and sham acupuncture at any stage (stage 1: MD 0.40, 95% CI -0.12 to 0.93; stage 2: MD 0.49, 95 % CI -0.26 to 1.24; stage 3: MD 0.67, 95% CI -0.18 to 1.53). Reduction in gagging as reported by the participant also showed no difference between acupuncture at P6 and sham acupuncture (MD 0.86, 95% CI -1.13 to 2.85). The quality of the evidence for all outcomes was very low.No noteworthy adverse effects were reported.We did not find trials evaluating any other interventions used to manage gagging in people undergoing dental treatment.

We found very low quality evidence from a single trial that was insufficient to conclude if there is any benefit of acupuncture 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.