How reliable are follow-up studies on odontogenic keratocysts?

Follow-up studies on odontogenic keratocysts have reported widely varying recurrence rates. This raises the question of how reliable these studies are and how the results should be interpreted. The aim of this study was to critically assess the information from all follow-up studies published since 2004 against a set of criteria to determine how thorough the study was. These criteria include the exclusion of the orthokeratinized variant, exclusion of cysts associated with nevoid basal cell carcinoma syndrome, and appropriate reporting of dropouts. A search of four electronic databases covering the years 2004-2022 was performed. Only studies with a sufficient follow-up period (covering a range of 1-8 years) were included. Studies with fewer than 40 cases were excluded. Fourteen relevant studies were identified in the literature search. The vast majority of these studies had considerable shortcomings, giving rise to serious doubts about the validity of their recurrence rate results. Of note, these studies have often been included in meta-analyses that report on the best treatment options to reduce the tendency of recurrences. The results of this review strongly suggest that multicentre studies with strict protocols should be performed to advance knowledge of the presentation of recurrences, both the timing and frequency.