Management of gag reflex for patients undergoing dental treatment.

BACKGROUND: 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. OBJECTIVES: To assess the effects of pharmacological and non-pharmacological interventions for the management of gagging in people undergoing dental treatment. SEARCH METHODS: 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. SELECTION CRITERIA: 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. DATA COLLECTION AND ANALYSIS: 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. MAIN RESULTS: 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. AUTHORS' CONCLUSIONS: 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.

Interventions for the management of taste disturbances.

BACKGROUND: The sense of taste is very much essential to the overall health of the individual. It is a necessary component to enjoying one's food, which in turn provides nutrition to an individual. Any disturbance in taste perception can hamper the quality of life in such patients by influencing their appetite, body weight and psychological well-being. Taste disorders have been treated using different modalities of treatment and there is no consensus for the best intervention. Hence this Cochrane systematic review was undertaken. OBJECTIVES: To assess the effects of interventions for the management of patients with taste disturbances. SEARCH METHODS: We searched the Cochrane Oral Health Group Trials Register (to 5 March 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2014), MEDLINE via OVID (1948 to 5 March 2014), EMBASE via OVID (1980 to 5 March 2014), CINAHL via EBSCO (1980 to 5 March 2014) and AMED via OVID (1985 to 5 March 2014). We also searched the relevant clinical trial registries and conference proceedings from the International Association of Dental Research/American Association of Dental Research (to 5 March 2014), Association for Research in Otolaryngology (to 5 March 2014), the US National Institutes of Health Trials Register (to 5 March 2014), metaRegister of Controlled Trials (mRCT) (to 5 March 2014), World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) (to 5 March 2014) and International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Clinical Trials Portal (to 5 March 2014). SELECTION CRITERIA: We included all randomised controlled trials (RCTs) comparing any pharmacological agent with a control intervention or any non-pharmacological agent with a control intervention. We also included cross-over trials in the review. DATA COLLECTION AND ANALYSIS: Two authors independently, and in duplicate, assessed the quality of trials and extracted data. Wherever possible, we contacted study authors for additional information. We collected adverse events information from the trials. MAIN RESULTS: We included nine trials (seven parallel and two cross-over RCTs) with 566 participants. We assessed three trials (33.3%) as having a low risk of bias, four trials (44.5%) at high risk of bias and two trials (22.2%) as having an unclear risk of bias. We only included studies on taste disorders in this review that were either idiopathic, or resulting from zinc deficiency or chronic renal failure.Of these, eight trials with 529 people compared zinc supplements to placebo for patients with taste disorders. The participants in two trials were children and adolescents with respective mean ages of 10 and 11.2 years and the other six trials had adult participants. Out of these eight, two trials assessed the patient reported outcome for improvement in taste acuity using zinc supplements (RR 1.45, 95% CI 1.0 to 2.1; very low quality evidence). We included three trials in the meta-analysis for overall taste improvement (effect size 0.44, 95% CI 0.23 to 0.65; moderate quality evidence). Two other trials described the results as taste acuity improvement and we conducted subgroup analyses due to clinical heterogeneity. One trial described the results as taste recognition improvement for each taste sensation and we analysed this separately. We also analysed one cross-over trial separately using the first half of the results. None of the zinc trials tested taste discrimination. Only one trial tested taste discrimination using acupuncture (effect size 2.80, 95% CI -1.18 to 6.78; low quality evidence).Out of the eight trials using zinc supplementation, four reported adverse events like eczema, nausea, abdominal pain, diarrhoea, constipation, decrease in blood iron, increase in blood alkaline phosphatase, and minor increase in blood triglycerides. No adverse events were reported in the acupuncture trial.None of the included trials could be included in the meta-analysis for health-related quality of life in taste disorder patients. AUTHORS' CONCLUSIONS: We found very low quality evidence that was insufficient to conclude on the role of zinc supplements to improve taste perception by patients, however we found moderate quality evidence that zinc supplements improve overall taste improvement in patients with zinc deficiency/idiopathic taste disorders. We also found low quality evidence that zinc supplements improve taste acuity in zinc deficient/idiopathic taste disorders and very low quality evidence for taste recognition improvement in children with taste disorders secondary to chronic renal failure. We did not find any evidence to conclude the role of zinc supplements for improving taste discrimination, or any evidence addressing health-related quality of life due to taste disorders.We found low quality evidence that is not sufficient to conclude on the role of acupuncture for improving taste discrimination in cases of idiopathic dysgeusia (distortion of taste) and hypogeusia (reduced ability to taste). We were unable to draw any conclusions regarding the superiority of zinc supplements or acupuncture as none of the trials compared these interventions.