Keratocystic Odontogenic Tumor Recurrence Rates With Enucleation and Curettage Using Carnoy’s Versus Modified Carnoy’s Solution

Tuesday, October 8, 2013: 1:35 PM
Jason Dashow DDS, MD, Oral and Maxillofacial Surgery, University of Michigan, Ann Arbor, MI
Joseph I. Helman DMD, Dept. of Oral and Maxillofacial Surgery, University of Michigan, Ann Arbor, MI
Sean P. Edwards DDS, MD, Oral and Maxillofacial Surgery, Univ. of Michigan, Ann Arbor, MI
Jonathan McHugh MD, Pathology, Univ. of Michigan, Ann Arbor, MI
Brent B. Ward DDS, MD, Oral and Maxillofacial Surgery, University of Michigan Hospital, Ann Arbor, MI
Keratocystic Odontogenic Tumor (KOT) is a common tumor of the jaws. KOT is locally destructive, has a high recurrence rate, and may be associated with increased morbidity secondary to multiple surgical procedures. Enucleation and curettage with application of Carnoy’s solution has been prescribed as one treatment modality with the advantage of decreased recurrence over enucleation alone. In the United States, the FDA has banned the use of chloroform for compounding resulting in a number of surgeons adopting the use of “Modified Carnoy’s” solution (without chloroform) for chemical cauterization in KOT treatment. The purpose of this study was to examine the effect of chloroform removal on recurrence rates in a series of KOTs treated by enucleation and curettage (E&C), with application of Carnoy’s Solution (CS) versus Modified Carnoy’s Solution (MC).

A Retrospective review of 210 patients with pathological diagnosis of KOT treated by three surgeons at a single center between January 1996 and December 2012 was completed.  Patients with Gorlin’s syndrome, patients treated by surgical means other than E&C with CS or MC, and patient’s with less than 12 months of post-surgical follow up were excluded from the study. All patients had biopsy confirmation of recurrence. To decrease bias, patients with recurrence were categorized as such and their subsequent treatment outcomes were excluded from the study. Seventy-five patients ultimately met inclusion criteria. Demographic, clinical, radiographic, and histological data was collected for each patient. Surgical treatment consisted of E&C and a 3-minute application of CS or MC to the walls of the bony defect.

A two-tailed student’s t-test was utilized for comparison of means and fisher exact test for recurrence vs. no recurrences. A p value of 0.05 was considered statistically significant.

The mean follow up for CS patients was 44.75 mo. (13-144) vs. 27.23 (12-51) for MC patients). This difference was statistically significant (p=.01) and expected given that the switch to MC as a change of practice driven by the FDA in the mid 2000’s. Recurrences where more than twice as common in patients treated with MC 5/26 (19.2%) vs. CS 4/48 (8.3%) which did not reach statistical significance (p=0.263). Average time to recurrence was 41.5 mo. in CS vs. 30 mo. for MC which was also not statistically significant p=0.09.

While the small sample size and lack of statistical significance limit robust conclusions, our findings support the concept of a higher recurrence rate for MC vs. CS. In theory, the development of 2 additional recurrences in the MC group over the next 17 months would both equalize the follow-up period for the groups and lead to a statistically significant difference in outcomes. While at present these results only raise concern that this difference may exist, it is an important consideration for those utilizing MC for treatment of KOT.

Johnson NR, Batstone MD, Savage NW. Management and recurrence of keratocystic odontogenic tumor: a systematic review. Oral surg oral med oral pathol oral radiol. 2012 July 6.

Pogrel, MA. The keratocystic odontogenic tumor. Oral Maxillofac Surg Clin North Am. 2013 Feb: 25 (1): 21-30.