Dredging Method-A Conservative Approach for the Treatment of Keratocystic Odontogenic Tumor -
Keratocystic odontogenic tumor (KCOT) was previously designated as odontogenic keratocyst, which stresses the benign behavior of this lesion. In 2005, WHO Working Group recommends the term KCOT as it better reflects its neoplastic nature.
The most important clinical feature of the KCOT is its potential for locally destructive behavior, its recurrence rate, and its tendency to multiplicity. The traditional method for the treatment of KCOT is surgical enucleation. However, due to the lining of the cyst being delicate, the presence of the daughter cyst and the fact that KCOT frequently recur, this method is not sufficient. In such cases, additional surgical treatment, such as marginal resection or segmental resection should be considered. The resection of the mandible including involving condyle, wide anterior region and young patient is associated with numbers of complications, such as loss of jaw support, deformity, dysfunction and psychological distress even after reconstruction. To overcome these disadvantages by invasive surgery, to eliminate the tumor completely and to restore the normal form and function of the jaw, dredging method is performed for the treatment of KCOT in our division. In this study, we evaluate the clinical outcome of KCOT treated with dredging method.
Patients and Methods
The term “Dredging Method” is a conservative surgical procedure in which, deflation and enucleation or only enucleation, followed by repeated dredging is applied to accelerate new bone formation by removing out the scar tissue from the bony cavity. In 132 patients, 122 patients had a single lesion and the other had multiple lesions, so that 151 KCOTs were treated in our university between 1985 and 2005. The lesions more than 25mm in greatest dimension, were treated by dredging methods and the other lesions were treated by enucleation alone or deflation followed by enucleation.
Results
The daughter cysts was found in 50% patients with multiple lesions and in 18% of patients with single lesions. The daughter cyst was found in 31.8% of multilocular lesion that was much higher rate than the unilocular lesions in 18.6%. In 57 lesions treated with dredging method, only 28 lesions were cleared out at enucleation step, but the other lesions were still found the remaining cyst at dredging step in pathologically. During the observation period, the recurrence was identified only in 7 out of 151 lesions (4.6%), between 34 and 124 months after final dredging.
Conclusions
Daughter cyst was found in much higher rate in multiple cases and multilocular lesions. The recurrence rate of the KCOT in our division was 4.6%. Long term follow up is essential for dredging method.
References
1. Nigel R. Johnson, Martin D. Batstone, Neil W. Savage : Management and recurrence of keratocystic odontogenic tumor : a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol. 116 : 271–276, 2013
2. Fadi Titinchi, Christoffel J. Nortje : Keratocystic odontogenic tumor : a recurrence analysis of clinical and radiographic parameters. Oral Surg Oral Med Oral Pathol Oral Radiol. 114 : 136–142, 2012