Background: Children who have been abused could exhibit lesions and diseases in their oral cavity and develop psychological consequences towards the dentist-patient relationship. Objectives: Analyse the oral lesions and diseases, the psychological consequences and understand the role of the dentist in the detection and notification of child abuse. Methods: Systematic review, according to PRISMA statement, with two search strategies in the MEDLINE/PubMed database. 19 publications were included after the application of selection and eligibility criteria. Results: Physical-abuse-related lesions and Münchausen syndrome are not pathognomonic; this requires the detection of indicators of suspicion. Physical-neglect diseases usually have associated other chronic health problems. Specifically, diseases related to sexual abuse are the oral infection caused by Treponema pallidum and Neisseria gonorrhoeae; while other lesions and diseases might only suggest abuse. The most frequent psychological sign of child abuse in the dentist-patient relationship is dental phobia. Typically, when detecting and notifying, dentist face the following barriers: insufficient information; fear of wrong suspicion; impact in the professional practice; fear of consequences on the minor; fear of violence against the dentist; lack of knowledge of necessary documents/procedures; fear of judicial statement. Conclusions: Child-abuse-related lesions and diseases often appear in the oral region. Dentists play a fundamental role in the detection and notification of those. It is essential to establish training and action protocols as well as reliance strategies in the patient-dentist relationship.