Evidence that ectopic upper third molars can result in upper second molar impactions: A case series.

Introduction: The aim of these four case reports was to illustrate the presence of potential upper second molar impactions associated with ectopic third molars and to highlight that some cases have an atypical radiographic presentation.

Case presentations: Four patients (age range = 7-12 years) with various malocclusions presented to the paediatric and orthodontic departments for treatment to address their presenting complaints. Incidental radiographic findings demonstrated potentially impacted upper second molars associated with ectopic third molars. In all of these cases, a joint paediatric-orthodontic approach was adopted to address their dental health, prevent upper second molar impaction and to treat their malocclusion.

Discussion: Careful and systematic review of radiographic imaging was necessary in order to diagnose these cases correctly. These cases demonstrated that it was not always simple to determine impactions, particularly as identification of third molar crypts can be difficult. On occasion, sequential radiographic monitoring is advocated, particularly in patients in the mixed dentition; however, clinicians must be mindful of the risks of ionising radiation as it is not routine practice to irradiate a patient multiple times.

Conclusion: The series of cases highlights the need for a systematic assessment of OPTs to identify ectopic upper third molars. The input from radiologists is invaluable and if necessary, supplemental three-dimensional cone-beam computed tomography can be performed.