Oral injuries: systematic review

Child Protection Evidence is a resource for clinicians across the UK and internationally to inform clinical practice, child protection procedures and professional and expert opinion in the legal system.


Facial and intra-oral trauma has been described in up to 49% of infants and 38% of toddlers who have been physically abused. A torn upper labial frenum (often referred to as frenulum or phrenum) is described as the most common abusive injury to the mouth.

This systematic review evaluates the scientific literature on abusive and non-abusive oral injuries in children published up until April 2023 and reflects the findings of eligible studies. The 2023 update combined the previous two clinical questions to the single question below:

  • What oral injuries are associated with physical child abuse?

The 2023 update included six new studies that have aimed to describe the frequency and characterisation of oral injuries in children who have been physically abused.  The certainty of abuse diagnosis was high in this update with five out of six studies using multidisciplinary assessment for confirmed abuse cases (rank 2) and one study using criminal court proceedings to confirm abuse (abuse ranking criteria 1).

Key findings:

    • Evidence in the literature supports full clinical evaluation for a child with a torn upper labial frenum taking into consideration their age, developmental stage and mechanism of injury. In the absence of concerns about an abusive cause, any other injuries or social concerns, the presence of a torn upper labial frenum alone is not pathognomonic of physical abuse.
    • Evidence from the literature shows that a torn labial frenum can be associated with severe abuse. Like many other injuries, a torn labial frenum may be strongly indicative of physical abuse in a young infant or non-mobile child and has also been described as a sentinel injury.
    • In older, mobile children, torn labial frenum is a well described accidental injury where there is a clear history of an appropriate accidental mechanism of injury.
    • Oropharynx bruising was suggested by one study to be a possible indicator of physical abuse.
Disclaimer: This is a summary of the systematic review findings up to the date of our most recent literature search. If you have a specific clinical case, we strongly recommend you read all of the relevant references as cited and look for additional material published outside our search dates.

Original reviews and content © Cardiff University, funded by NSPCC

Updates and new material by RCPCH July 2023

While the format of each review has been revised to fit the style of the College and amalgamated into a comprehensive document, the content remains unchanged until reviewed and new evidence is identified and added to the evidence-base. Updated content will be indicated on individual review pages.

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