MATERIALS AND METHODS: 100 smokers and 100 nonsmokers ages 18-50 years were recruited for this study in Kota Bharu, Malaysia. Oral hygiene (good/fair vs poor) was determined using the Simplified Oral Hygiene Index, and the halitosis level was measured using a Halimeter. Subjects were instructed to refrain from consuming foods containing garlic, onions, strong spices, alcohol and using mouthwashes 48 h prior to the examination. The halitosis levels were quantified by recording volatile sulphur compounds (VSCs) three times at 3-min intervals, resulting in a mean halitosis score. Various statistical analyses were performed, ranging from simple frequency analysis to multivariable modelling.

RESULTS: The proportions of subjects with poor oral hygiene and high halitosis were 24.0% and 41.5%, respectively. According to bivariate analyses, both problems were significantly less frequent among younger adults (halitosis), females, subjects with higher education, those with adequate habits to maintain good oral hygiene, those who had recent dental visits and those self-reporting fewer health problems. The percentages of poor oral hygiene and high halitosis were significantly higher in smokers (p < 0.001). However, almost all these variables failed to show significance in the multivariate analyses, with the exceptions of smoking for both poor oral hygiene and halitosis, education for poor oral hygiene, and age, self-reported health problems and time since the previous dental visit for halitosis.

OBJECTIVES: The objectives of this review were to assess the effects of various interventions used to control halitosis due to oral diseases only. We excluded studies including patients with halitosis secondary to systemic disease and halitosis-masking interventions.

SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 8 April 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 3) in the Cochrane Library (searched 8 April 2019), MEDLINE Ovid (1946 to 8 April 2019), and Embase Ovid (1980 to 8 April 2019). We also searched LILACS BIREME (1982 to 19 April 2019), the National Database of Indian Medical Journals (1985 to 19 April 2019), OpenGrey (1992 to 19 April 2019), and CINAHL EBSCO (1937 to 19 April 2019). The US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (8 April 2019), the World Health Organization International Clinical Trials Registry Platform (8 April 2019), the ISRCTN Registry (19 April 2019), the Clinical Trials Registry - India (19 April 2019), were searched for ongoing trials. We also searched the cross-references of included studies and systematic reviews published on the topic. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA: We included randomised controlled trials (RCTs) which involved adults over the age of 16, and any intervention for managing halitosis compared to another or placebo, or no intervention. The active interventions or controls were administered over a minimum of one week and with no upper time limit. We excluded quasi-randomised trials, trials comparing the results for less than one week follow-up, and studies including advanced periodontitis.

DATA COLLECTION AND ANALYSIS: Two pairs of review authors independently selected trials, extracted data, and assessed risk of bias. We estimated mean differences (MDs) for continuous data, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS: We included 44 trials in the review with 1809 participants comparing an intervention with a placebo or a control. The age of participants ranged from 17 to 77 years. Most of the trials reported on short-term follow-up (ranging from one week to four weeks). Only one trial reported long-term follow-up (three months). Three studies were at low overall risk of bias, 16 at high overall risk of bias, and the remaining 25 at unclear overall risk of bias. We compared different types of interventions which were categorised as mechanical debridement, chewing gums, systemic deodorising agents, topical agents, toothpastes, mouthrinse/mouthwash, tablets, and combination methods. Mechanical debridement: for mechanical tongue cleaning versus no tongue cleaning, the evidence was very uncertain for the outcome dentist-reported organoleptic test (OLT) scores (MD -0.20, 95% CI -0.34 to -0.07; 2 trials, 46 participants; very low-certainty evidence). No data were reported for patient-reported OLT score or adverse events. Chewing gums: for 0.6% eucalyptus chewing gum versus placebo chewing gum, the evidence was very uncertain for the outcome dentist-reported OLT scores (MD -0.10, 95% CI -0.31 to 0.11; 1 trial, 65 participants; very low-certainty evidence). No data were reported for patient-reported OLT score or adverse events. Systemic deodorising agents: for 1000 mg champignon versus placebo, the evidence was very uncertain for the outcome patient-reported visual analogue scale (VAS) scores (MD -1.07, 95% CI -14.51 to 12.37; 1 trial, 40 participants; very low-certainty evidence). No data were reported for dentist-reported OLT score or adverse events. Topical agents: for hinokitiol gel versus placebo gel, the evidence was very uncertain for the outcome dentist-reported OLT scores (MD -0.27, 95% CI -1.26 to 0.72; 1 trial, 18 participants; very low-certainty evidence). No data were reported for patient-reported OLT score or adverse events. Toothpastes: for 0.3% triclosan toothpaste versus control toothpaste, the evidence was very uncertain for the outcome dentist-reported OLT scores (MD -3.48, 95% CI -3.77 to -3.19; 1 trial, 81 participants; very low-certainty evidence). No data were reported for patient-reported OLT score or adverse events. Mouthrinse/mouthwash: for mouthwash containing chlorhexidine and zinc acetate versus placebo mouthwash, the evidence was very uncertain for the outcome dentist-reported OLT scores (MD -0.20, 95% CI -0.58 to 0.18; 1 trial, 44 participants; very low-certainty evidence). No data were reported for patient-reported OLT score or adverse events. Tablets: no data were reported on key outcomes for this comparison. Combination methods: for brushing plus cetylpyridium mouthwash versus brushing, the evidence was uncertain for the outcome dentist-reported OLT scores (MD -0.48, 95% CI -0.72 to -0.24; 1 trial, 70 participants; low-certainty evidence). No data were reported for patient-reported OLT score or adverse events.

METHODS: Fit to the Rasch model was examined in 6648 8-to-15-year-olds from Australia, New Zealand, Brunei, Cambodia, Hong Kong, Malaysia, Thailand, Germany, United Kingdom, Brazil and Mexico.

RESULTS: In all but two items, the initial five answer options were reduced to three or four, to increase precision of the children's selection. Items 10 (Shy/embarrassed) and 11 (Concerned what others think) showed an 'extra' dependency between item scores beyond the relationship related to the underlying latent construct represented by the instrument, and so were deleted. Without these two items, the CPQ was unidimensional. The three oral symptoms items (4 Food stuck in teeth, 3 Bad breath and 1 Pain) were required for a sufficient person-item coverage. In three out of 14 items (21 %), Europe and South America showed regional differences in the patterns of how the answer options were selected. No differential item functioning was detected for age.

CONCLUSION: Except for a few modifications, the present analysis supports the combination of items, the cross-cultural validity of the CPQ with 14 items and the extension of the age range from 8 to 15 years.