It is widely acknowledged that parental beliefs (self-efficacy) about oral health and parental oral health-related behaviours play a fundamental role in the establishment of preventative behaviours that will mitigate against the development of childhood dental caries. However, little attention has been given to the wider perspective of family functioning and family relationships on child oral health. For oral health researchers, exploration of this association requires the use of reliable, valid and appropriate assessment tools to measure family relationships. In order to promote methodologically sound research in oral health, this systematic review aims to provide a guide on self-report psychometric measures of family functioning that may be suitable to utilize when exploring childhood dental caries. This systematic review has identified 29 self-report measures of family functioning and evaluated them in terms of their psychometric support, constructs measured and potential utility for oral health research. The majority of the measures reported adequate levels of reliability and construct validity. Construct evaluation of the measures identified five core domains of family functioning, namely ‘communication', ‘cohesion/engagement', ‘control', ‘involvement' and ‘authoritative/rigid parenting style'. The constructs were subsequently evaluated with respect to their potential relevance to child oral health. Herewith this review provides a framework to guide future research to explore family functioning in furthering our understanding of the development of childhood dental caries.