Discussion
Impaction of teeth is a common presentation that dentists and surgeons routinely diagnose. Most commonly this involves mandibular third permanent molars impacting against the adjacent second molar. When partially erupted, this can lead to recurrent infections involving the pericoronal space. Cyst development can also be a complication of impaction, sometimes causing displacement of the tooth and adjacent structures. Our case was particularly interesting, not only due to its kissing molar formation, but because it was bilateral in nature. Currently only nine other cases of bilateral kissing molars could be found in the literature.
This case highlighted how there is no set protocol or guidelines in place for the management of kissing molars. Some cases may present a high risk of pathological fracture and inferior alveolar nerve injury. In these cases, a cone beam CT can prove helpful to provide information regarding the buccolingual positioning of the IAN, width of remaining bone and therefore aid planning[5]. For our patient, the risk of damage to bilateral inferior alveolar nerves was increased due to their close proximity to the second molars. Therefore, following discussion with the patient, it was decided that surgical intervention was only to be carried out in the lower left quadrant where the dentigerous cyst was more advanced and presented a higher risk of infection due to its oral communication.
For some patients, orthodontic alignment of the impacted molars may be possible so an orthodontic opinion should be sought where appropriate. Alternatively, kissing molars can be monitored, but a discussion with the patient regarding the risks of nearby root resorption and cyst formation should be balanced against the risks of surgical intervention.
Some clinicians routinely prescribe post operative steroids following surgical removal of kissing molars[2]. Improved patient comfort, reduced swelling and trismus following third molar removal and post operative steroid use has also been reported[6].
There remains no concrete evidence regarding the aetiology of kissing molars. It is theorised by some that an ectopic tooth bud is responsible and that early cystic development around a molar can cause their crowns to displace[7]. Mucopolysaccharidosis[8] and hyperplastic dental follicles[9] has also been suggested.