原文題目(出處)： Keratocystic odontogenic tumor: systematic review with analysis of 72 additional cases from Mumbai, India. Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:128-39.
原文作者姓名： Kaustubh Sansare, Mamta Raghav, Muralidhar Mupparapu, Nilesh Mundada, Freny R. Karjodkar, Shivani Bansal, Rajiv Desai
通訊作者學校： Oral Medicine and Radiology, Nair Hospital and Dental College. Division of Oral and Maxillofacial Radiology, Department of Oral Medicine, University of Pennsylvania School of Dental Medicine, Philadelphia, Oral Pathology, Nair Hospital and Dental College.
報告者姓名(組別)： 吳亭瑩 (Intern I 組)
報告日期： 102.5.10
內文：
I. Introduction
1. KCOT renamed by WHO in 2005
2. Definition: A benign uni- or multicystic intraosseous tumor of odontogenic origin with a characteristic lining of parakeratinized stratified squamous epithelium and potentially aggressive infiltrative behavior. It may be solitary or multiple. The latter is usually one of the stigmata of the inherited nevoid basal cell carcinoma syndrome (NBCCS).
3. KOTs are associated with inactivation of PTCH, the tumor suppressive gene.
4. This study determines the radiographic and clinical features more accurately for the Indian population, which will help in further diagnosis of keratocystic odontogenic tumor.
II. Materials and Methods
1. Searching the medical literature for the period from 1957 to March 2012.
2. Scientific databases namely Pubmed Plus, Medline (Pre-Medline and Medline), Cochrane Database of Systematic Reviews (evidence-based medicine), Dentistry and Oral Sciences Source, Access Science, Embase, Evidence-Based Medicine Reviews Multifile, Google Scholar, ISI Journal Citation Reports, and Ovid Multi-database
3. Search keywords included were keratocystic AND odontogenic AND tumor OR odontogenic AND keratocyst OR primordial.
4. Inclusion criteria: All case series, histologically confirmed as a parakeratinized variety, were included in this SR.
(In the pre-2005 case series where both orthokeratinized and parakeratinized variety were reported, only parakeratinized reports were selected.)
5. Excluded:
i. Syndromic cases of NBCCS were excluded from this review, because multiple tumors in this syndrome are often not synchronous.
ii. Articles on the peripheral or extraosseous variant of KOT were excluded.
6. Additional cases: Cases from Nair Hospital Dental College (Indian)
i. Cases diagnosed as KOT and OOC after 2005 and those diagnosed as OKC before 2005.
ii. Cases were reviewed for a period of 9 years, from January 2001 to
December 2009.
iii. Final diagnosis was made on the basis of histopathology.
iv. The various variables considered in this study were age, sex, arch and site of lesion, nature (single/multiple) of occurrence, and radiographic findings. Results compared with findings from the rest of the world.
7. Lesion site definition
Maxillary Mandible
Class I tooth 13-23 distal sides tooth 33-43 distal sides
Class II tooth 14M-distal, 24M-distal area tooth 34M-distal, 44M-distal area Class III lesions that extended into both
anterior and posterior segments of the maxilla.
lesions extending into both anterior and posterior segments of mandible.
Class IV lesions from third molar to third molar crossing the midline.
lesions from third molar to third molar crossing the midline.
Class V X lesions limited to posterior
segment, angle of the mandible, ramus, condyle, and coronoid process.
III. Results
1. A total of 17,449 articles were found, total of 65 articles were finally selected for the SR.
2. The results were mainly divided into 4 major groups based on origin of the genetic family: American, Caucasian, East Asian and Pacific, and African and South Asian.
American North and south America Caucasian Europe
African and South Asian
Africa and Eastern, Northern, Southern Indian subcontinent East Asian and
Pacific
Southeastern Asia and the Australian continent
3. Distribution:
America: 19, Caucasian: 22, Africa: 5, East Asian: 19
4. Comparison:
i. Number of KOT per year: higher in African and East Asian African: 8.93 per year/ World: 6.35 per year
ii. Male: predominantly in global groups iii. Mean age: higher in America
iv. Swelling: more frequent in East Asian and Caucasian groups Rare in global groups
v. Pain at first: only 1 report in African and Subsaharan group vi. Mandible common: world wide
Especially: Ammerican (71%) and Caucasian (74%)
vii. Radiographic features: NA presented, paucity of radiologic details noted in earlier studies
viii. Unilocular KOT: predominant in all global groups
Except: African group (present) and Subsaharan group (previous) ix. Border: well defined in East Asian
poorly defined in American group
x. Buccolingual expansion: common in additional case xi. Root resorption: significantly higher in East Asian
xii. KOT with unerupted tooth: not common in any of the groups
5. Additional case:
i. Only KOT was discussed.
ii. Age: average age: 30.7 yrs, predominant at 3rd (n = 24) and 2nd (n = 18) decades.
iii. Male: Female = 3:1, Mandibular-to-maxillary ratio = 2.61 : 1
iv. Sites: most common over Class 2 area. (tooth 34M- and 44M-distal) v. Unilocular more common both maxillary and mandibular.
IV. Discussion
1. 2005 reclassify:
i. Parakeratinized lesion as KOT ii. Orthokeratinized lesion as OOC
2. KOT and OOC: completely different lesions 3. KOT – inactivation of PTCH
i. Importance of genetic origin of KOT p’t.
ii. The SR is the first compilation of KOT in Indian population iii. Additional cases/ African and South Asian community
1. Results might match – genetic belonging, geographic proximity 4. Awareness or not
i. American and Caucasian groups: greater number of case report and earlier diagnosed
ii. African and South Asian groups: higher number of cases reported per year.
iii. Higher number of KOTs per year in the African and East Asian groups indicates a higher incidence of KOT in these groups
5. Mean age
i. Mean age higher in American group of the present SR.
ii. Combined analysis of the American and Caucasian groups: didn’t reflect higher mean age.
iii. KOT in American groups may occur much earlier.
6. Pain and multilocular
i. Rare, only 1 report presented it common in African groups.
7. Maxilla/Mandible predominated
i. Maxilla predominated in African group – because of Sri Lankan report.
8. Swelling: East Asian, Caucasian African and Latin American groups.
i. American groups not involved.
ii. Might due to increased size because of poor awareness.
9. Buccolingual expansion
i. Known as rare buccolingual expansion.
ii. Significantly higher in East Asian group.
10. Root resorption
i. Significantly higher in East Asian group.
11. Unerupted tooth
i. Significantly higher in American group.
ii. Might be high incidence of prophylactic removal of impacted teeth in America.
12. Additional Cases
i. OOC in Indian community: 6.5%, world average: 11%
7% for Subsaharan and 8% each for the Latin American and East Asian groups
ii. KOT in additional cases: 93.5%,
Subsaharan (93%), Latin American (92%), and East Asian (92%) groups but more than the Western group (89%)
iii. Male/ Female ratio = 3 1.3 to 1.6 worldwide.
iv. Age: predominately 3rd decade, both male and female.
1st decade of female and 3rd decade of male during previous SR.
v. Mandibular: Maxillary involved = 2:1 vi. Most common sites: class 2 > 5 > 1 > 4
Class 4 rare might because early examination due to oral radiographic examinations..etc.
vii. Unilocular variant dominated: 63.3%
American (unilocular 74.5%), and Caucasian (unilocular 86.4%), and East Asian (unilocular 54.7%) groups
viii. Good marginal definition
Poorly defined borders in American group ix. Root resorption: rare in India area.
V. Conclusions KOT:
1. Painless, occasionally swelling in certain population, majorly mandible involves, Unilocular variety more common. Root resorption and buccolingual expansion mainly in East Asian group.
2. Additional cases (Indian population):
i. 72 KOTs and 5 OOCs.
ii. Male major, 3rd decade predominately.
題號 題目
1 Which one about Keratinized odontogenic tumor (KOT) and Orthokeratinized Odontogenic cyst is in correct?
(A) Recurrence rate of KOT is higher than OOC.
(B) KOT and OOC both predominated in posterior mandible area.
(C) Histopathologic findings: KOT and OOC both has palisaded basal cell.
(D) KOT and OOC are different kinds of lesion.
答案(C) 出處：Oral and Maxillofacial Pathology, edition 3
題號 題目
2 Which one about KOT was wrong?
(A) Majorly infect 2rd to 3nd decade’s male.
(B) Root resorption and buccolingual expansion mainly happens in East Asian group cases.
(C) Reclassified by WHO in 2005 and named as Keratinized Odontogenic Tumor because of it’s character like high recurrence rate.
(D) Associated to activation of PTCH gene and 9th chromosome changing.
答案(D) 出處：Oral and Maxillofacial Pathology, edition 3
Keratocystic odontogenic tumor: systematic review with analysis
of 72 additional cases from Mumbai, India
