Long-term follow-up on keratocysts treated according to a defined protocol.

A prospective study was conducted on 82 odontogenic keratocysts (OKCs) diagnosed in 80 patients over a 25 year period. The clinical and radiographic data were correlated, which resulted in an accurate picture of the clinical presentation, relationship with teeth and incidence of lingual perforations in mandibular OKCs. In 40% of the cysts no suspicion had arisen before surgery, in 60% the diagnosis was secured before surgery. This last group of patients was treated according to a defined protocol, with the exception of the maxillary OKCs, which entailed excision of the attached, overlying mucosa and enucleation of the cyst after which the defect was treated with Carnoy's solution. The other patients underwent just enucleation of the cysts. For the first 5 years the patients were seen every year, thereafter every 2 years if possible. Recurrences (9/82) were mainly found in the patients in which the cyst had just been enucleated. Only three cysts recurred in the group treated according to the above mentioned protocol. Most recurrences presented within 5 years, but late recurrences did occur even after 25 years. The aetiology and pathogenesis of OKCs is briefly discussed in the light of the present findings. It is concluded that the suggested treatment protocol and follow-up schedule provides a safe means to manage a lesion that is known to recur and may even give rise to life threatening situations.