The keratocystic odontogenic tumour (KCOT, odontogenic keratocyst (OKC)) was first described in the literature in 1956 and is classified by the World Health Organization classified as a benign odontogenic tumour. It is generally accepted that they arise from the remnants of the dental lamina and are benign but locally aggressive and tend to reoccur. They account for between 2% and 11% of all jaw cysts and can occur at any age. They are more common in males than females with a male:female ratio of approximately 2:1. This review attempted to determine the recurrence rate of KCOT following treatment.
A wide range of databases(Cochrane Library, MEDLINE, EIFL, Ovid and ISI.) and reference lists of the retrieved articles were searched for English language papers. Articles related to (extraosseous) varianst of KCOT/OKC and nevoid basal cell carcinoma syndrome (Gorlin-Goltz syndrome) were excluded .
They identified 1568 articles but only 2 retrospective reviews met the inclusion criteria. These studies included 108 lesions and six treatment modalities. The recurrence rates identified were
- 0% for resection,
- 0% for enucleation with peripheral ostectomy and Carnoy’s solution,
- 18.18% for enucleation with peripheral ostectomy,
- 26.09% for enucleation alone,
- 40% for marsupialisation,
- 50% for enucleation with Carnoy’s solution.
The overall recurrence rate was 23.15%.
The authors concluded
The present review discusses the methodological weaknesses of many of the studies analysed. No high quality evidence was obtained to evaluate recurrence rates related to treatment modalities of keratocystic odontogenic tumour.
Kaczmarzyk T, Mojsa I, Stypulkowska J. A systematic review of the recurrence rate for keratocystic odontogenic tumour in relation to treatment modalities. Int J Oral Maxillofac Surg. 2012 Mar 23. [Epub ahead of print] PubMed PMID: 22445416.
A Cochrane review by Sharif et al was published in 2010. The aim of that review was to assess the available evidence comparing the effectiveness of surgical interventions and adjuncts for the treatment of KCOTs. That review was restricted to randomised controlled trials and non were found.
They concluded at the time that
There are no published randomised controlled trials relevant to this review question, therefore no conclusions could be reached about the effectiveness or otherwise of the interventions considered in this review. There is a need for well designed and conducted randomised controlled trials to evaluate treatments for KCOTs.
An earlier review was conducted by Blanas et al in 2000 which concluded.
Although the existing literature consists of retrospective consecutive case series, it appears that resection or enucleation with adjunctive therapy is associated with recurrence rates that are lower than those associated with enucleation alone.
A quick search of the clinical trials databases find no registered RCTs on this topic so it would appear that despite 60 years knowledge of the KCOT and at least 3 systematic review we still have not conducted high quality studies to provide robust answers to managing this tumour!
Sharif FNJ, Oliver R, Sweet C, Sharif MO. Interventions for the treatment of keratocystic odontogenic tumours (KCOT, odontogenic keratocysts (OKC)). Cochrane Database of Systematic Reviews 2010, Issue 9. Art. No.: CD008464. DOI: 10.1002/14651858.CD008464.pub2.
Blanas N, Freund B, Schwartz M, Furst IM. Systematic review of the treatment and prognosis of the odontogenic keratocyst. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000 Nov;90(5):553-8. Review. PubMed PMID: 11077375.