Commentary

For most orthodontists, whether they work in specialist practice or in hospital, the management of ectopically erupting maxillary permanent canines occupies a significant amount of their clinical time. Although the prevalence of impacted, displaced or ectopic maxillary canines is reported as only between 1% to 3%,1,2 this can lead to dental crowding as well as movement or root resorption of neighbouring teeth and, more rarely, cyst formation.3,4 It is generally accepted that the majority (85%) of ectopic maxillary canines move palatally,5 although a more recent CT study,3 suggests the figure may be closer to 50%. Unless it is decided to leave and monitor the unerupted canine tooth, treatment will usually involve surgical exposure followed by orthodontic treatment with fixed appliances, and this may be prolonged.6 Alternatively, where it is suspected that the permanent maxillary canine is developing palatally, it is common practice to extract the deciduous predecessor. However, previous reviews,7,8 have shown that there is only limited evidence supporting this interceptive treatment.

This paper is an update of a Cochrane review published in 2009 and represents a further search of the literature. The authors identified a further 125 references since the original study. From this only two studies have been regarded as acceptable for inclusion in this update. Interestingly, both of these papers, Leonardi 2004, Baccetti 2008,9,10 were previously available and were excluded from the 2009 study. It was evident that there was some debate about their inclusion in this review. Although both were described as randomised control trials, they had previously been excluded due to deficiencies in reporting and insufficient data. It was hoped to address these problems by contacting one of the lead researchers, Dr Baccetti, but tragically he died in November 2011. Reviewers were unable to establish from the co-authors further important information concerning the design of the studies and the outcome data. It is evident from the review that both of these studies provided incomplete information about randomisation and that the groups were not matched at the outset. In addition, the outcome data were incomplete and it was also concluded that both studies were at a high overall risk of bias. This review states that neither trial provided any further evidence of the positive effects of extraction of the deciduous canine tooth in the management of palatally displaced maxillary permanent canines.

This Cochrane review thus reaches the same conclusions as its predecessor,7 and also the review carried out by Naoumova et al. in 2010.8

This latter paper went on to state that further, better controlled and well designed RCTs are required and if carried out, ideally they should also include assessment of patient satisfaction and pain experienced, as well as an analysis of the cost and side-effect of treatment.

This information does not assist the practitioner who cannot palpate one or both of the maxillary permanent canines in their 10-year-old patient. A decision whether to leave and observe the situation or to extract one or more of the deciduous canines will be made without a strong evidence base. In such a case, referral to a specialist orthodontist for an opinion at least, would be the best course of action.

Practice point

  • Any clinical examination of patients aged nine and above should involve palpation of the permanent maxillary canines if these teeth have not yet started to erupt

  • If the position of an unerupted maxillary canine is not clear, refer promptly for a specialist orthodontic opinion.