This study confirms that intra‐oral injury occurs in a significant number of children who have been physically abused. Injuries are widely distributed to the lips, gums, tongue and palate and include fractures, intrusion and extraction of the dentition, bruising, lacerations and bites.
There is a paucity of published scientific literature about the torn labial frenum. There are no studies defining the incidence of torn labial frena in abuse and none that compare the injury in abused and non‐abused children. It is impossible, therefore, to ascribe a probability of abuse for a torn labial frenum. Published studies are limited to 30 highly selected cases where a torn labial frenum is described in predominantly pre‐school children who had suffered serious abuse, and where the majority of cases were fatal with extensive associated injuries. The only substantiated cause of an abusive torn labial frenum was a direct blow. There were no recorded cases of forced feeding, twisting or rubbing causing this injury. The literature includes mention of torn labial frena that were not abusive, and therefore a torn frenum in isolation cannot be described as pathognomonic of physical abuse. Clearly the finding of an unexplained torn labial frenum in a young child warrants full investigation, but the paucity of data in the literature and the highly selected nature of cases reported precludes defining an age band where concern would be highest. A diagnosis of physical abuse should not be based on a single injury in isolation, but arrived at in the context of the child's medical, social and developmental history and the explanation offered for the injury.
Some of the largest series in the literature
31,32 were not eligible for inclusion as they were only ranked 5 for abuse. They included cases of suspected abuse, with no separation of data on those cases where abuse was actually confirmed.
It is important when assessing a possible torn labial frenum to consider rarer congenital abnormalities of the labial frena such as midline diastema,
33,34 hypertrophic frenum in association with hypoplastic left heart syndrome,
35 and multiple frena in other congenital heart syndromes such as Ellis‐van Creveld or Pallister‐Hall
36,37 as possible explanations of the abnormality.
The most frequently reported abusive injury to the mouth is not a torn labial frenum, as has been suggested,
4 but injury to the lips. This assumes that the mouths of all abused children in the various series were fully examined. As these were retrospective studies of case notes,
1,21 this is far from clear. None of the described abusive intra‐oral injuries had any diagnostic characteristics, except for a bitten tongue.
1,13,15,17,19,20,21,24,25,26,27,28,29,31 It is clear that paediatricians should always examine a child's mouth when assessing a child for suspected abuse. As it is doubtful whether non‐dental specialists would recognise the significance of grey discolouration of the teeth as a micro‐fracture or previous injury,
38 or whether they would be able confidently to distinguish this from the characteristic yellow‐brown to grey discoloration found in dentinogenesis imperfecta, it is important to involve dental colleagues. This would be particularly pertinent if co‐existent skeletal fractures were found, as may be the case with combined osteogenesis imperfecta and dentinogenesis imperfecta.
39 It is important that paediatricians are aware of the appropriate primary and secondary dentition expected at a given age, in order to question the absence of permanent teeth, as described by Carrotte.
15Many of the intra‐oral injuries described in abused children are likely to be seen by general dental practitioners, yet dentists make very few child protection referrals. This is highlighted by Cotton,
40 who noted that of 20

000 child abuse investigations only 12 were initiated by dentists. A survey by Becker
et al of 1332 dentists in the USA, where there was mandatory reporting with a response rate of 40%, noted that 22 cases of child abuse were seen but only four (18%) were referred to social services,
1 despite a legal requirement to report suspected abuse. A similar study by Malecz
41 showed that not only did few dentists report abuse cases, but 7% of 155 respondents said that under no circumstances would they report child abuse. Reasons cited included uncertainty about diagnosis and fear of litigation, although practitioners making a referral “in good faith” are protected from litigation in the United States.
3 Even 12 years later, a survey of 250 dentists, 157 of whom responded, showed that 50% of dentists had suspected abuse but one third did not refer the case,
42 and similar reluctance has recently been documented in the UK where 21% of dentists did not refer cases they suspected of having been abused.
43 There have been a number of initiatives in the United States to tackle this issue,
44,45 and Welbury
et al have developed a computer‐assisted learning programme for general dental practitioners in the United Kingdom,
46 and the British Dental Council have recently published guidance.
47There is no legal mandatory reporting of child abuse in the UK, but the British Dental Association has made it clear that dentists do have an ethical responsibility to report child abuse.
48 Clearly, those responsible for child protection training in each region must include dental practitioners and hygienists in such programmes, and offer ongoing support.
As in previous reviews,
12,49 children with disability were not represented. This is particularly disappointing as disabled children are recorded as being three times more likely to be abused than their able‐bodied counterparts.
50Whilst this review did not deal with dental neglect, a notable number of cases presented co‐existing neglect with resulting dental caries, likely to cause severe pain to the child.
25,28 Dental neglect while variably defined,
38 should be considered in any child with extensive dental caries or early childhood caries where appropriate dental care has not been sought.
51,52 This subject merits a review in its own right, in view of the potential implications in relation to pain, morbidity and faltering growth.
53Future research should be directed at determining the sensitivity and specificity of intra‐oral injuries in abuse by well designed comparative studies. It is clear that we need to define those children who sustain accidental torn frena, in isolation or otherwise, by age, developmental stage and co‐existent injury and cause, in order to aid the distinction from abusive torn frena. Attention should be given specifically to documenting the full extent of intra‐oral injuries in physically abused children and their co‐existent injuries, and this should include disabled children.