Background: Comforting behaviours, such as the use of pacifiers (dummies, soothers), blankets and finger or thumb sucking, are common in babies and young children. These comforting habits, which can be referred to collectively as 'non-nutritive sucking habits' (NNSHs), tend to stop as children get older, under their own impetus or with support from parents and carers. However, if the habit continues whilst the permanent dentition is becoming established, it can contribute to, or cause, development of a malocclusion (abnormal bite). A diverse variety of approaches has been used to help children with stopping a NNSH. These include advice, removal of the comforting object, fitting an orthodontic appliance to interfere with the habit, application of an aversive taste to the digit or behaviour modification techniques. Some of these interventions are easier to apply than others and less disturbing for the child and their parent; some are more applicable to a particular type of habit.
Objectives: The primary objective of the review was to evaluate the effects of different interventions for cessation of NNSHs in children. The secondary objectives were to determine which interventions work most quickly and are the most effective in terms of child and parent- or carer-centred outcomes of least discomfort and psychological distress from the intervention, as well as the dental measures of malocclusion (reduction in anterior open bite, overjet and correction of posterior crossbite) and cost-effectiveness.
Search methods: We searched the following electronic databases: the Cochrane Oral Health Group Trials Register (to 8 October 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 9), MEDLINE via OVID (1946 to 8 October 2014), EMBASE via OVID (1980 to 8 October 2014), PsycINFO via OVID (1980 to 8 October 2014) and CINAHL via EBSCO (1937 to 8 October 2014), the US National Institutes of Health Trials Register (Clinical Trials.gov) (to 8 October 2014) and the WHO International Clinical Trials Registry Platform (to 8 October 2014). There were no restrictions regarding language or date of publication in the searches of the electronic databases. We screened reference lists from relevant articles and contacted authors of eligible studies for further information where necessary.
Selection criteria: Randomised or quasi-randomised controlled trials in children with a non-nutritive sucking habit that compared one intervention with another intervention or a no-intervention control group. The primary outcome of interest was cessation of the habit.
Data collection and analysis: We used standard methodological procedures expected by The Cochrane Collaboration. Three review authors were involved in screening the records identified; two undertook data extraction, two assessed risk of bias and two assessed overall quality of the evidence base. Most of the data could not be combined and only one meta-analysis could be carried out.
Main results: We included six trials, which recruited 252 children (aged two and a half to 18 years), but presented follow-up data on only 246 children. Digit sucking was the only NNSH assessed in the studies. Five studies compared single or multiple interventions with a no-intervention or waiting list control group and one study made a head-to-head comparison. All the studies were at high risk of bias due to major limitations in methodology and reporting. There were small numbers of participants in the studies (20 to 38 participants per study) and follow-up times ranged from one to 36 months. Short-term outcomes were observed under one year post intervention and long-term outcomes were observed at one year or more post intervention. Orthodontics appliance (with or without psychological intervention) versus no treatmentTwo trials that assessed this comparison evaluated our primary outcome of cessation of habit. One of the trials evaluated palatal crib and one used a mix of palatal cribs and arches. Both trials were at high risk of bias. The orthodontic appliance was more likely to stop digit sucking than no treatment, whether it was used over the short term (risk ratio (RR) 6.53, 95% confidence interval (CI) 1.67 to 25.53; two trials, 70 participants) or long term (RR 5.81, 95% CI 1.49 to 22.66; one trial, 37 participants) or used in combination with a psychological intervention (RR 6.36, 95% CI 0.97 to 41.96; one trial, 32 participants). Psychological intervention versus no treatmentTwo trials (78 participants) at high risk of bias evaluated positive reinforcement (alone or in combination with gaining the child's co-operation) or negative reinforcement compared with no treatment. Pooling of data showed a statistically significant difference in favour of the psychological interventions in the short term (RR 6.16, 95% CI 1.18 to 32.10; I(2) = 0%). One study, with data from 57 participants, reported on the long-term effect of positive and negative reinforcement on sucking cessation and found a statistically significant difference in favour of the psychological interventions (RR 6.25, 95% CI 1.65 to 23.65). Head-to-head comparisonsOnly one trial demonstrated a clear difference in effectiveness between different active interventions. This trial, which had only 22 participants, found a higher likelihood of cessation of habit with palatal crib than palatal arch (RR 0.13, 95% CI 0.03 to 0.59).
Authors' conclusions: This review found low quality evidence that orthodontic appliances (palatal arch and palatal crib) and psychological interventions (including positive and negative reinforcement) are effective at improving sucking cessation in children. There is very low quality evidence that palatal crib is more effective than palatal arch. This review has highlighted the need for high quality trials evaluating interventions to stop non-nutritive sucking habits to be conducted and the need for a consolidated, standardised approach to reporting outcomes in these trials.