Maxillary odontogenic keratocyst

JADA, Vol. 134, July 2003 877 The canine region is the most common location for the odontogenic keratocyst in the maxilla. D E N T I S T R Y & M E D I C I N E views and intraoral periapical films, in most cases are adequate to determine the location and estimate the size of an OKC. Advanced imaging techniques like computerized tomography and magnetic resonance imaging can be useful in large cases involving the maxillary Copyright ©2003 American Dental Association. All rights reserved. sinus and the rare cases that extend to the skull base. Several studies of the clinical presentation of OKCs have been conducted. Most have shown that the mandible is involved more often than the maxilla. In addition, the posterior part of the mandible is the most common location for OKCs. There are inconsistencies regarding the predominant location of OKCs in the maxilla. One study shows that OKCs are divided equally between the anterior and the posterior maxilla, some show that there are more anterior lesions than posterior lesions, and others conclude that the posterior region is the predominant site. We used a retrospective analysis to establish the most common location of OKCs in the maxilla and compared our findings with previous reports of maxillary OKCs. METHODS We reviewed all cysts diagnosed as OKCs by the Oral and Maxillofacial Pathology Diagnostic Laboratory at the University of Florida College of Dentistry from July 1, 1993, to June 30, 2001. We obtained information regarding each case from a microscopic analysis of hematoxylin-eosin–stained sections and from biopsy forms submitted by clinicians. We included in the study only cases that satisfied the following clinical and histopathologic criteria: dadequate description of the anatomical location on the case history form; dadherence to histologic features described by Pindborg and Hansen for OKC; dno recurrent lesions. After selecting cases, we used the following criteria to define the locations of the lesions in each jaw: danterior—midline to distal surface of the lateral incisor; dcanine—distal surface of lateral incisor to mesial surface of the first premolar; dpremolar—mesial surface of the first premolar to the distal surface of the second premolar; dfirst and second molar—distal surface of the second premolar to the distal surface of the second molar; dthird molar and ramus—distal surface of the second molar to the distal surface of the third molar, including the ramus; dthird molar and tuberosity—distal surface of the second molar to the distal surface of the third molar, including the tuberosity. In addition, we categorized the cysts as: dperiapical/radicular lesions—lesions appearing radiographically consistent with a periapical/ radicular cyst; dpericoronal lesions—lesions appearing radiographically consistent with a dentigerous cyst; dlateral root lesions—lesions appearing consistent with a lateral periodontal cyst or lateral radicular cyst; dlesions not associated with a tooth. We recorded other clinical information such as age and sex for each case. We obtained information regarding the practitioner’s clinical diagnoses from the biopsy forms for the cases in the most common maxillary location. RESULTS Location. Of the 513 cases we reviewed, 120 did not meet various criteria, and we excluded them. In 62 cases, the history was incomplete; in 16 cases, the lesion was too large; 36 cases were recurrent; and in six cases, classic histologic features of OKC described by Pindborg and Hansen could not be identified with certainty due to the degenerative changes of the cystic epithelium secondary to intense inflammation in the wall. The pathologist (R.A.B.) initially diagnosed these six cases as “inflamed odontogenic cyst, suggestive of inflamed OKC.” A total of 398 OKCs from 393 patients satisfied the criteria for this study. There were 266 (66.8 percent) OKCs in the mandible and 132 (33.2 percent) in the maxilla, a ratio of 2:1. In the mandible, 137 (34.4 percent) cysts occurred in the third molar and ramus area, 41 (10.3 percent) in the premolar area, 41 (10.3 percent) in the canine area, 33 (8.3 percent) in the first and second molar area and 14 (3.5 percent) in the anterior area (Figure 1). In the maxilla, 54 (13.6 percent) cysts occurred in the canine area, 30 (7.5 percent) in the third molar and tuberosity region, 28 (7.0 percent) in the anterior area, 13 (3.3 percent) in the first and second molar area and seven (1.8 percent) in the premolar area (Figure 2). We also recorded the position of the OKCs in relation to the teeth and 878 JADA, Vol. 134, July 2003 D E N T I S T R Y & M E D I C I N E The data demonstrate that in the maxillary canine region odontogenic keratocysts may mimic other lesions. Copyright ©2003 American Dental Association. All rights reserved. show the relationships in Table 1. The most common site of involvement was the mandibular third molar and ramus region with 137 (34.4 percent) OKCs. The next most common site was the canine region of the maxilla with 54 (13.6 percent). Age. OKCs occurred in patients aged 10 to 94 years—a wide range of years. We show the age distribution in Figure 3. The peak incidence was 21.6 percent in the 70 to 79 years age group. Sex. Of the 393 patients, 221 were male (56.2 percent), and 172 (43.8 percent) were female. In one case, the sex of the patient was unspecified. The male-to-female ratio was 1.3:1, constituting a slight male predisposition. Maxillary canine region findings. Of the 132 maxillary cases, 54 (40.9 percent) occurred in the canine region. Of canine region OKCs, 27 were in the periapical/radicular position, and 25 were in the interproximal position. One cyst was in the coronal position, and one cyst was not associated with a tooth or previous extraction site (Table 1). The frequency of the clinical diagnoses submitted for the 54 cases in the maxillary canine region showed that OKC was mentioned as a diagnosis or one of the differential diagnoses in 17 (31.5 percent) cases, periapical cyst or granuloma in 14 (25.9 percent) cases, lateral periodontal cyst in 15 (27.8 percent) cases, globulomaxillary cyst in six (11.1 percent) cases, odontogenic tumor (adenomatoid odontogenic tumors, ameloblastoma and central giant cell granuloma) in five (9.3 percent) cases and dentigerous cyst in three (5.6 percent) cases (Table 2, page 881). DISCUSSION In our study, the age range was wide, from 10 to 94 years, with a peak incidence in the 70 to 79 years age group. Other studies reported a peak incidence in the second and third decades of life. JADA, Vol. 134, July 2003 879 D E N T I S T R Y & M E D I C I N E