原文題目

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口腔病理科 On-Line KMU Student Bulletin

原文題目(出處)： Frequency of odontogenic cysts and tumors: a systematic review. J Investig Clin Dent 2014;5:9-14

原文作者姓名： Nigel R. Johnson, Orla M. Gannon, Neil W. Savage, Martin D. Batstone

通訊作者學校： Department of Maxillofacial Surgery, Royal Brisbane and Womens’ Hospital, Brisbane, Queensland, Australia

報告者姓名(組別)：蔡沛倫 Intern K 組

報告日期： 2014.6.9

內文：

Abstract

1. A systematic review of the literature from 1993 to 2011 was undertaken examining frequency data of the most common odontogenic cysts and tumors.

2. There were 18297 odontogenic cysts reported. Among these cases, there were 9982 (54.6%) radicular cysts, 3772 (20.6%) dentigerous cysts and 2145 (11.7%) keratocystic odontogenic tumors.

3. With the reclassification of keratocystic odontogenic tumor in 2005 as an odontogenic tumor, there were 8129 odontogenic tumors reported with 3001 (36.9%) ameloblastomas, 1163(14.3%) keratocystic odontogenic tumors, 533 (6.5%) odontogenic myxomas, 337 (4.1%) adenomatoid odontogenic tumors and 127 (1.6%) ameloblastic fibromas.

4. This systematic review found that odontogenic cysts are 2.25 times more frequent than odontogenic tumors.

Introduction

1. Epidemiological data for odontogenic cysts and tumors have been reported extensively in the literature, with an emphasis on the more destructive lesions such as the keratocystic odontogenic tumor (KCOT) and ameloblastoma.

2. Odontogenic lesions can be divided discretely into cysts and tumors.

(1) cyst: an epithelial lined pathological cavity

(2) tumor: a solid tissue mass, not necessarily neoplastic 3. Odontogenic cysts:

(1) A radicular cyst is due to a long standing inflammatory process in the bone of the surrounding root apex with the proliferation of the epithelial rests of Malassez.

(2) Dentigerous cysts are developmental in origin, with fluid expanding the dental follicle peri-coronally.

(3) The KCOT arises from the dental lamina and other sources of odontogenic epithelium. This lesion tends to be more aggressive in its growth pattern, providing a higher recurrence rate than other odontogenic pathoses.

4. Odontogenic tumors:

(1) Ameloblastomas can be derived from any odontogenic epithelium ranging from the dental lamina ,to reduced enamel epithelium , to epithelial rests of Malassez and Serres , and possibly the basal layer of the overlying epithelium.

Ameloblastomas can have a varied radiographic appearance.

(2) Odontogenic myxoma is an intraosseous neoplasm consisting of myxomatous fibrous extracellular matrix originating from mesenchymal remnants.

(3) Adenomatoid odontogenic tumors arise from the dental lamina in the gubernacular cord of developing permanent teeth.

(4) Ameloblastic fibromas are similar in origin to ameloblastomas, being derived from the enamel organ or dental lamina, except there is a lack of dental hard

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tissue in the specimen.

5. The aim of this study was to systematically review all papers between 1993 and 2011 that provided frequency data for odontogenic cysts and tumors.

Methods

A systematic review was conducted using the databases CENTRAL, MEDLINE, and EMBASE.

Results

1. There were 5231 papers identified in the preliminary database search. Of these there were 10 papers that met the inclusion criteria that described odontogenic cysts.

2. There were 12 papers that met the inclusion criteria that described odontogenic tumors. With the change of the WHO classification describing KCOT as a tumor in 2005,there was a subset of 4 papers that dealt with KCOT under the odontogenic tumor classification.

3. All selected papers dealt with populations ranging from the 10~80.

4. The total number of cysts or tumors reported in each paper was combined.

Table2. Relative frequencies of selected odontogenic cysts

Table3. Relative frequencies of selected odontogenic tumors

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Table4. Relative frequencies of selected odontogenic tumors---after KCOT reclassification.

The relative frequency of KCOT in these papers was higher (36.6%) than was reported when KCOT was classified as an odontogenic cyst (11.7%).This is most likely due to the smaller numbers of odontogenic tumors reported as opposed to odontogenic cysts and is not a true increase in frequency.

Discussion

1. The specific odontogenic cysts and tumors were chosen for this review as they were the most common lesions across the literature. This review has found that odontogenic cysts are 2.25 times more frequent than odontogenic tumors.

2. There were several different odontogenic cysts and tumors that were diagnosed less frequently, and these other terms were only a small proportion of the overall total. Not all studies reviewed had these other variants present, therefore no comparison could be made.

3. As odontogenic cysts and tumors are not notifiable to any cancer or diseases registry, it is difficult to ascertain whether any of the data published are truly accurate.

4. The reclassification of KCOT from a cyst to a tumor by the WHO in 2005appears to have minimal influence on the frequency of other odontogenic tumors.

Conclusion

1. Radicular cysts are the most frequent odontogenic cyst, followed by the dentigerous cyst and KCOT (when classified as a cyst).

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2. Ameloblastomas are the most frequent odontogenic tumor, followed by KCOT (when classified as a tumour), odontogenic myxoma, adenomatoid odontogenic tumor, and ameloblastic fibroma.

題號題目

1 下列何種囊腫不屬於發育性囊腫？

(A) 含齒囊腫（dentigerous cyst）

(B) 原基性囊腫（primordial cyst）

(C) 根尖囊腫（radicular cyst）

(D) 戈林氏囊腫（Gorlin cyst）

答案(C) 出處：Oral and Maxillofacial Pathology, 3^rd edition P.130

Epithelium at the apex of a nonvital tooth presumably can be stimulated by inflammation to form a true epithelium-lined cyst, or periapical cyst

題號題目

2 在下顎正中門齒的X光片，有如圖所示之放射線透過區，門牙的活性

測驗均為正常反應，最可能的診斷為：

(A) 根尖囊腫（periapical cyst）

(B) )腺樣齒源性囊腫（glandular odontogenic cyst）

(C) 造釉細胞瘤（ameloblastoma）

(D) 根尖牙骨質骨質發育不良（periapical cemento-osseous dysplasia）

答案( D) 出處：Oral and Maxillofacial Pathology, 3^rd edition P.641

Periapical cemento-osseous dysplasia : periapical radiograph showing multiple radiolucent lesions at the apices of the anterior mandibular teeth