Background Mobile phones are potentially an invaluable tool in addressing the global challenge associated with dental caries as they may elicit behaviour change by incorporating numerous behaviour change techniques (BCTs) to address an individual's capability, opportunity and motivation.Methods The methodology for this review is published on the PROSPERO database (CRD42017078414).Results Two randomised controlled trials were included, both were undertaken with orthodontic patients and both reported significantly reduced plaque scores in the intervention group compared with the control at final follow-up. One study also reported statistically significantly lower gingival bleeding scores and caries in the intervention group at final follow-up. The risk of bias was 'unclear' for both studies and neither study intervention appeared to be based on specific theories of behaviour change. Of 93 BCTs available, only six were utilised across the two trials. The overall strength of evidence for the effectiveness of mobile phones in reducing plaque score was rated as moderate using GRADE, while the effectiveness in reducing bleeding scores was considered to be high.Conclusion There is some evidence that mobile phones are effective in improving adherence to oral hygiene advice in orthodontic patients. The generalisability of this review is limited due to the small number of trials and the unclear risk of bias of included studies.