Résumé

<p>Abstract<br>Background: To describe epidemiological features of 565 Chinese patients with odontogenic keratocysts (OKC),&nbsp;<br>to investigate possible prognostic factors related to recurrence, and to analyse features of recurrent OKC (rOKC).<br>Material and Methods: A retrospective chart review of 565 cases of OKC treated between 2003 and 2015 was&nbsp;<br>undertaken. The probability of recurrence related to prognostic factors including large size, cortical perforation&nbsp;<br>combined with involved teeth in the lumen of the cyst, inflammation, sites of the involved lesion, sex, and daughter&nbsp;<br>cyst variables were analysed. The subsequent relapse of each OKC was compared.<br>Results: Patients ranged in age from 7 to 81 years (mean age, 28.4 years) and, of those affected, 66.9% were male&nbsp;<br>and 33.1% were female. Mandibular OKC occurred in 63.01% and 36.99% occurred in the maxilla, 80.53% of&nbsp;<br>patients had non-rOKC, 10.44% rOKC, and 9.03% had multiple OKC lesions. Enucleation with preservation of the&nbsp;<br>involved teeth in the cystic lesion combined with cortical perforation was statistically associated with high recur-<br>rence rate, as were daughter cysts, and multilocular lesions. The number of recurrences and the average time (in&nbsp;<br>years) to relapse decreased from the first relapse of OKC to the third relapse, and the difference was significant&nbsp;<br>(P&lt;.05).</p><p>Conclusions: Preservation of the involved teeth combined with cortical perforation appeared to be a potential prog- </p><p>nostic factor associated with high recurrence. The follow-up evaluation period for rOKC with ≥ 2 previous treatments </p><p>should be shorter than for first-time rOKC. The decreasing average duration (years postoperatively) to relapse was </p><p>related to the number of rOKCs, timing of relapse, and rOKC type. </p><p>Key words: Keratocystic odontogenic tumor, risk of recurrence, involved teeth and cortical perforation, relapse, epi- </p><p>demiological features.</p><p>&nbsp;</p>