- Email: [email protected]
Odontogenic Tumours in Thailand
Odontogenic Tumours inSurg Thailand Asian J Oral Maxillofac 2004;16:166-171. CLINICAL OBSERVATIONS
Odontogenic Tumours in Thailand Kittipong Dhanuthai Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Abstract Objective: This study was performed to determine the incidence of odontogenic tumours in the Thai population. Patients and Methods: The pathology records of 1020 patients with odontogenic tumours diagnosed at the Department of Oral Pathology, Chulalongkorn University, Thailand, during a 26-year period from 1977 to 2002 were reviewed and reclassified according to the World Health Organization 1992 criteria. Clinical data, including age, gender, and anatomical distribution of lesions, were also collected and analysed. Results: Odontogenic tumours accounted for 7.6% of all the oral and maxillofacial lesions (n = 13,472). Of these, 1010 patients (99%) had benign tumours and 10 (1%) had malignant tumours. Ameloblastoma, odontoma, and myxoma were the commonest lesions encountered. The mean age for benign odontogenic tumours was 30.0 years and for malignant lesions was 33.5 years, with the majority (54.1%) of odontogenic tumours presenting in the second and the third decades of life. Women outnumbered men for benign tumours, while the reverse was true for malignant tumours. Benign and malignant odontogenic tumours showed a predilection for the mandible, especially the posterior region. Conclusions: Odontogenic tumours are uncommon lesions in the Thai population. The data from this study show similar trends to those from Asian and African series with minor differences. Key words: Odontogenic, Retrospective, Thailand, Tumour
Introduction Teeth develop from a complex interaction between ectodermal and ectomesenchymal tissues. Remnants of these tissues are left behind in the jaws both during and after odontogenesis and can give rise to a heterogeneous group of odontogenic lesions. 1 According to the World Health Organization (WHO) Histologic Classification of Odontogenic Tumors, these tumours fall into 3 categories:2 • tumours originating from odontogenic epithelium without odontogenic ectomesenchyme • tumours originating from odontogenic epithelium with odontogenic ectomesenchyme, with or without dental hard tissue • tumours originating from odontogenic ectomesenchyme with or without odontogenic epithelium. Correspondence: Kittipong Dhanuthai, Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Henri-Dunant Road, Patumwan District, Bangkok 10330, Thailand. Tel: (66 2) 218 8582; Fax: (66 2) 218 8581; E-mail: [email protected]
166
There are numerous published reports of odontogenic tumours from North America, Africa, and Asia. However, there is little information pertaining to the incidence and distribution of odontogenic tumours in the Thai population. The purpose of this study was to determine the incidence and distribution of odontogenic tumours according to age, gender, and anatomical location of these lesions in the Thai population and to compare these data with other reported series.
Patients and Methods The pathology records of 1020 patients with odontogenic tumours diagnosed at the Department of Oral Pathology, Chulalongkorn University, Thailand, during a 26-year period from 1977 to 2002 were retrieved. Hematoxylin and eosin slides were reviewed and reclassified according to the WHO Histologic Classification of Odontogenic Tumors criteria of 1992. Clinical information, namely age, gender, and anatomical distribution of the lesions was collected from the biopsy records. For the purpose Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Dhanuthai
of anatomical location, the maxilla was divided into 3 regions: • anterior (midline to the distal surface of the canine) • middle (the mesial surface of the first premolar to the distal surface of the third molar) • posterior (tuberosity). Similarly, the mandible was divided into 3 regions: • anterior (midline to the distal surface of the canine) • middle (the mesial surface of the first premolar to the distal surface of the third molar) • posterior (angle, ramus, condyle, and coronoid process). Locations other than the aforementioned sites were recorded as ‘others’. Data collected were analysed by descriptive statistics.
Results Of 13,472 oral and maxillofacial lesions, 1020 patients (7.6%) had odontogenic tumours. Among these, 1010 (99%) were benign tumours and 10 (1%) were malignant tumours. The 3 most common odontogenic tumours in descending order of frequency were ameloblastoma (51.3%), odontoma (20.4%), and myxoma (8.2%). The most common tumour in the subcategory of tumours originating from odontogenic epithelium without odontogenic ectomesenchyme was ameloblastoma (51.3%). The most common tumour in the subcategory of tumours originating from odontogenic epithelium with odontogenic ectomesenchyme (with or without dental hard tissue) was odontoma (20.4%). The most common tumour in the subcategory of tumours originating from odontogenic ectomesenchyme with or without odontogenic epithelium was myxoma (8.2%). The distribution of various odontogenic tumours is presented in Table 1. The odontogenic tumours in this series were encountered over a wide age range, from 1 to 83 years. The mean age of patients with benign odontogenic tumours was 30.0 years, whereas that of patients with malignant odontogenic tumours was 33.5 years. 540 tumours (54.1%) occurred in patients in the second and third decades of life, with a peak incidence in the second decade (28.3%). The age distribution in this series is presented in Table 2. Among the benign odontogenic tumours, 575 (56.9%) were encountered in women and 434 (42.9%) were encountered in men, Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Number
Percent
Ameloblastoma
523
51.3
Ameloblastic fibroma
18
1.8
Ameloblastic fibro-odontoma
8
0.8
Ameloblastic odontoma
8
0.8
Adenomatoid odontogenic tumour
57
5.6
Cementoblastoma
18
1.8
Calcifying odontogenic cyst
34
3.3
Complex odontoma
134
13.1
Compound odontoma
74
7.3
Odontogenic myxoma
84
8.2
Odontogenic fibroma
29
2.8
Calcifying epithelial odontogenic tumour
20
1.9
Squamous odontogenic tumour
3
0.3
Malignant ameloblastoma
7
0.7
Ameloblastic fibrosarcoma
1
0.1
Odontogenic myxosarcoma
2
0.2
Total
1020
100
Table 1. Distribution of various odontogenic tumours.
a male to female ratio of 1:1.3. Among malignant odontogenic tumours, 7 (70.0%) were encountered in men and 3 occurred in women, a male to female ratio of 2.3:1. The gender distribution of odontogenic tumours is presented in Table 3. The anatomical distribution of each type of odontogenic tumour is summarised in Table 4. Overall, both benign and malignant odontogenic tumours showed a predilection for the mandible, especially in the posterior region. Ameloblastoma demonstrated a strong predilection for the mandible with the ratio of mandible to maxilla as high as 10.8 to 1. If individual tumours were considered separately, ameloblastic fibro-odontoma, ameloblastic odontoma, adenomatoid odontogenic tumour, calcifying odontogenic cyst, compound odontoma, squamous odontogenic tumour, and myxosarcoma occurred in the maxilla more often than in the mandible.
Discussion Odontogenic tumours are relatively uncommon lesions accounting for less than 3% of all the oral and maxillofacial lesions in most reported series.3-8 The few reports from Africa showed the frequency of odontogenic tumours to be roughly 30% of all oral and maxillofacial lesions.9,10 The frequency of 167
Odontogenic Tumours in Thailand Age (years) 0-9
10-19
20-29
30-39
40-49
50-59
60-69
70-79
80-89
Unknown
Mean
Ameloblastoma
9
84
130
113
87
55
28
8
2
7
34.21
Ameloblastic fibroma
4
9
4
1
0
0
0
0
0
0
15.61
Ameloblastic fibro-odontoma
1
5
1
0
0
1
0
0
0
0
17.75
Ameloblastic odontoma
0
6
0
0
1
1
0
0
0
0
21.50
Adenomatoid odontogenic tumour
1
35
17
1
3
0
0
0
0
0
19.21
Cementoblastoma
0
7
3
3
4
0
0
0
0
1
26.41
Calcifying odontogenic cyst
0
19
8
5
1
0
1
0
0
0
22.12
Complex odontoma
3
50
41
18
10
5
3
3
0
1
25.99
Compound odontoma
3
39
17
8
1
4
1
0
0
1
21.00
Odontogenic myxoma
6
20
21
14
9
6
3
4
0
1
30.29
Odontogenic fibroma
1
5
9
4
6
4
0
0
0
0
32.03
Calcifying epithelial odontogenic tumour
1
4
2
5
3
2
3
0
0
0
35.40
Squamous odontogenic tumour
0
0
0
2
1
0
0
0
0
0
39.00
Malignant ameloblastoma
0
0
2
2
2
1
0
0
0
0
37.00
Ameloblastic fibrosarcoma
0
0
1
0
0
0
0
0
0
0
20.00
Odontogenic myxosarcoma
0
0
1
1
0
0
0
0
0
0
28.00
Total
29
283
257
177
128
79
39
15
2
11
Table 2. Age distribution of odontogenic tumours. Male
Female
Unknown
Total
Male to female ratio
Ameloblastoma
251
271
1
523
1:1.1
Ameloblastic fibroma
6
12
0
18
1:2
Ameloblastic fibro-odontoma
5
3
0
8
1:0.6
Ameloblastic odontoma
2
6
0
8
1:3
Adenomatoid odontogenic tumour
16
41
0
57
1:2.6
Cementoblastoma
10
8
0
18
1:0.8
Calcifying odontogenic cyst
14
20
0
34
1:1.4
Complex odontoma
49
85
0
134
1:1.7
Compound odontoma
29
45
0
74
1:1.6
Odontogenic myxoma
32
52
0
84
1:1.6
Odontogenic fibroma
9
20
0
29
1:2.2
Calcifying epithelial odontogenic tumour
8
12
0
20
1:1.5
Squamous odontogenic tumour
3
0
0
3
NA
Malignant ameloblastoma
6
1
0
7
1:0.2
Ameloblastic fibrosarcoma
0
1
0
1
NA
Odontogenic myxosarcoma
1
1
0
2
1:1
Total
441
578
1
1020
Abbreviation: NA = not applicable.
Table 3. Gender distribution of odontogenic tumours.
odontogenic tumours (7.6%) in this study is slightly higher than in previous studies,3-8 probably because of the university hospital setting where referrals, especially for ameloblastoma, are received from many hospitals and private clinics. Another 168
explanation may be that many more (and possibly all) cases of reactive and inflammatory lesions in western Europe and North America are submitted for histopathologic examination than in other parts of the world. Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Dhanuthai
Maxilla
Mandible
Others
Unknown
Maxillary: mandibular ratio
Anterior
Midline
Posterior
Anterior
Midline
Posterior
Ameloblastoma
26
36
6
162
399
175
11
3
1:10.8
Ameloblastic fibroma
2
2
0
6
14
1
0
0
1:5.3
Ameloblastic fibro-odontoma
4
3
1
0
4
1
0
0
1:0.6
Ameloblastic odontoma
2
3
2
2
1
0
0
0
1:0.4
Adenomatoid odontogenic tumour
35
17
1
11
9
0
1
1
1:0.4
Cementoblastoma
2
1
0
2
12
0
1
0
1:4.7
Calcifying odontogenic cyst
18
7
0
10
8
0
0
0
1:0.7
Complex odontoma
31
31
2
15
60
5
0
0
1:1.3
Compound odontoma
39
10
0
17
14
1
0
1
1:0.7
Odontogenic myxoma
20
19
4
17
33
8
4
3
1:1.3
Odontogenic fibroma
6
7
0
7
15
0
0
0
1:1.7
Calcifying epithelial odontogenic tumour
6
2
0
7
9
0
1
1
1:2
Squamous odontogenic tumour
2
2
0
0
0
0
0
0
NA
Malignant ameloblastoma
0
2
1
2
3
3
0
0
1:2.7
Ameloblastic fibrosarcoma
0
0
0
0
0
0
0
1
NA
Odontogenic myxosarcoma
0
1
1
0
0
0
0
0
NA
Abbreviation: NA = not applicable.
Table 4. Anatomical distribution of odontogenic tumours.
In this study, ameloblastoma ranked as the most common odontogenic tumour, similar to studies from Asia and Africa, but this was in contrast to studies from North and South America, which demonstrated that odontoma was the most common odontogenic tumour. The explanation for this disparity may be that most odontomas are asymptomatic lesions and the majority of people in developing countries in Asia and Africa do not undergo routine radiographic examination. Only when the lesion produces symptoms or disfigurement would they seek medical attention. Some odontomas are removed without being sent for histopathologic examination even though this is considered to be poor clinical practice. Fregnani et al also suggested that the discordant results in the frequency of ameloblastoma and odontoma in different studies might be due to the location where the data were collected.11 Normally, data collected from general hospitals showed a higher incidence of ameloblastoma than odontoma, while those from dental hospitals showed the opposite. These authors stated that ameloblastomas were diagnosed in dental schools, but treatments were often carried out in general hospitals.11 Lastly, geographic Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
and ethnic factors might be another explanation for the differences.4 In this study, ameloblastoma accounted for 51.3% of all odontogenic tumours, which was comparable to those by Adebayo et al (54.0%),10 Komori (57.0%),12 Odukoya (58.5%),13 and Wu and Chan (59.4%).3 The age and gender distributions of ameloblastoma in the present study were in accordance with previous studies with only minor differences.14-21 For instance, ameloblastomas in the present study occurred almost equally between genders, while studies from China,22 India,23 Nigeria,10,18 and Switzerland24 showed a male predominance. Regarding the site of occurrence, ameloblastomas in the present study showed a strong predilection for the mandible (91.5%) with only 8.5% occurring in the maxilla. This figure was comparable to those from Asia20,22 and Africa,10 but lower than studies from Turkey25 (18.8%) and Switzerland (19.2%).24 The compound and complex odontomas combined represented 20.4% of all odontogenic tumours. This figure was comparable to that from 169
Odontogenic Tumours in Thailand
Turkey,25 and lies somewhere between those from China,22 Africa,10,13 and the American continent.4,5,7,8 Several studies showed that compound odontomas were more common than complex odontomas,22,26-29 which was in contrast to the present study and that of MacDonald-Jankowski.30 Most studies, including ours, reported that odontomas present in the second and third decades of life.26-30 The present study and that of Lu et al22 showed that compound odontomas occurred more than complex odontomas in younger patients, while Katz26 reported that compound and complex odontomas demonstrated a similar age distribution. In this study and others,10 both compound and complex odontomas showed a predilection for women, but a number of studies reported a nearly equal gender distribution.4,26,27,29 The anterior maxilla was the site of predilection for compound odontoma, as in previous studies, 4,26,30 whereas complex odontoma showed a predilection for the anterior maxilla and mandibular premolar-molar region as in the studies of MacDonald-Jankowski 30 and Mosqueda-Taylor et al.4 Odontogenic myxomas accounted for 8.2% of all the odontogenic tumours in this study. This figure was comparable with that from the Chinese study,22 higher than the North American studies,5,7 and lower than the African and Turkish studies. 13,25 Most myxomas in the present study were encountered in the second to fourth decades of life as in previous studies,22,31 and occurred in women more often than men as in other studies.4,7,10,25,31 Several studies, including ours, showed that myxomas preferentially occurred in the mandible, especially the posterior part.4,10,22,31 Malignant odontogenic tumours are rare in the Thai population, accounting for only 1.00% of all odontogenic tumours and 0.07% of all oral and maxillofacial lesions. The figure from this study was comparable to that of Gunhan et al25 (1.5%), but lower than those of Odukoya13 (4.84%) and Lu et al22 (6.1%). Most studies, including ours, showed that odontogenic carcinomas outnumber odontogenic sarcomas. The most common malignant odontogenic tumour in this study was malignant ameloblastoma and this is in agreement with Lu et al.22 Malignant ameloblastomas predominantly 170
occurred in men and in the mandible more often than the maxilla, as in the studies of Odukoya,13 Lu et al,22 and Gunhan et al.25 In conclusion, odontogenic tumours are uncommon oral and maxillofacial lesions. Ameloblastoma is the most common odontogenic tumour in the Thai population, as in most Asian and African series, but different from most North and South American series in which odontoma ranks as the most common odontogenic tumour. The incidence and distribution of patient age and gender, and site of predilection in the present study are in accordance with most Asian and African series with only minor differences. Malignant odontogenic tumours are extraordinarily rare oral and maxillofacial lesions in the Thai population, with odontogenic carcinoma outnumbering odontogenic sarcoma. The most common odontogenic carcinoma in the present study was malignant ameloblastoma. However, the number of malignant odontogenic tumours was too small to draw any meaningful conclusions regarding age, gender, and site of predilection for these lesions.
Acknowledgements I would like to thank all staff in the Department of Oral Pathology for their contributions to this research.
References 1. Melrose RJ. Benign epithelial odontogenic tumors. Semin Diagn Pathol 1999;16:271-287. 2. Kramer IRH, Pindborg JJ, Shear M. Histological typing of odontogenic tumours, 2nd ed. Berlin: Springer-Verlag; 1992. 3. Wu PC, Chan KW. A survey of tumours of the jawbones in Hong Kong Chinese: 1963-1982. Br J Oral Maxillofac Surg 1985;23:92-102. 4. Mosqueda-Taylor A, Ledesma-Montes C, Caballero-Sandoval S, Portilla-Robertson J, RuizGodoy Rivera LM, Meneses-Garcia A. Odontogenic tumors in Mexico: a collaborative retrospective study of 349 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84: 672-675. 5. Daley TD, Wysocki GP, Pringle GA. Relative incidence of odontogenic tumors and oral and jaw cysts in a Canadian population. Oral Surg Oral Med Oral Pathol 1994;77:276-280. Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
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6. Ochsenius G, Ortega A, Godoy L, Penafiel C, Escobar E. Odontogenic tumors in Chile: a study of 362 cases. J Oral Pathol Med 2002;31:415-420. 7. Regezi JA, Kerr DA, Courtney RM. Odontogenic tumors: analysis of 706 cases. J Oral Surg 1978; 36:771-778. 8. Santos JN, Pinto LP, de Figueredo CR, de Souza LB. Odontogenic tumors: analysis of 127 cases. Pesqui Odontol Bras 2001;15:308-313. 9. Arotiba JT, Ogunbiyi JO, Obiechina AE. Odontogenic tumours: a 15-year review from Ibadan, Nigeria. Br J Oral Maxillofac Surg 1997;35: 363-367. 10. Adebayo ET, Ajike SO, Adekeye EO. Odontogenic tumours in children and adolescents: a study of 78 Nigerian cases. J Craniomaxillofac Surg 2002;30:267-272. 11. Fregnani ER, Fillipi RZ, Oliveira CR, Vargas PA, Almeida OP. Odontomas and ameloblastomas: variable prevalences around the world? Oral Oncol 2002;38:807-808. 12. Komori A. Odontogenic tumors. In: Nikai H, Okabe H, editors. Pathology for dental students: oral pathology. Tokyo: Ishiyaku Publishers; 1995:209-221. 13. Odukoya O. Odontogenic tumors: analysis of 289 Nigerian cases. J Oral Pathol Med 1995;24: 454-457. 14. Sirichitra V, Dhiravarangkura P. Intrabony ameloblastoma of the jaws. An analysis of 147 Thai patients. Int J Oral Surg 1984;13:187-193. 15. Ueno S, Nakamura S, Mushimoto K, Shirasu R. A clinicopathologic study of ameloblastoma. J Oral Maxillofac Surg 1986;44:361-365. 16. Kameyama Y, Takehana S, Mizohata M, Nonobe K, Hara M, Kawai T, Fukaya M. A clinicopathological study of ameloblastomas. Int J Oral Maxillofac Surg 1987;16:706-712. 17. Siar CH, Ng KH. Ameloblastoma in Malaysia — a 25-year review. Ann Acad Med Singapore 1993;22:856-860. 18. Olaitan AA, Adeola DS, Adekeye EO. Ameloblastoma: clinical features and management of 315 cases from Kaduna, Nigeria. J Craniomaxillofac Surg 1993;21:351-355. 19. Chidzonga MM, Lopez Perez VM, Portilla Alvarez AL. Ameloblastoma: the Zimbabwean
Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
experience over 10 years. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82:38-41. 20. Kim SG, Jang HS. Ameloblastoma: a clinical, radiographic, and histopathologic analysis of 71 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:649-653. 21. Reichart PA, Philipsen HP, Sonner S. Ameloblastoma: biological profile of 3677 cases. Eur J Cancer B Oral Oncol 1995;31B:86-99. 22. Lu Y, Xuan M, Takata T, Wang C, He Z, Zhou Z, Mock D, Nikai H. Odontogenic tumors. A demographic study of 759 cases in a Chinese population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998 ;86:707-714. 23. Potdar GG. Ameloblastoma of the jaw as seen in Bombay, India. Oral Surg Oral Med Oral Pathol 1969;28:297-303. 24. Zwahlen RA, Gratz KW. Maxillary ameloblastomas: a review of the literature and of a 15-year database. J Craniomaxillofac Surg 2002; 30:273-279. 25. Gunhan O, Erseven G, Ruacan S, Celasun B, Aydintug Y, Ergun E, Demiriz M. Odontogenic tumours. A series of 409 cases. Aust Dent J 1990; 35:518-522. 26. Katz RW. An analysis of compound and complex odontomas. ASDC J Dent Child 1989;56: 445-449. 27. Ng KH, Siar CH. A clinicopathologic study of odontomas: Malaysian findings. J Nihon Univ Sch Dent 1997;39:171-175. 28. Owens BM, Schuman NJ, Mincer HH, Turner JE, Oliver FM. Dental odontomas: a retrospective study of 104 cases. J Clin Pediatr Dent 1997;21: 261-264. 29. Miki Y, Oda Y, Iwaya N, Hirota M, Yamada N, Aisaki K, Sato J, Ishii T, Iwanari S, Miyake M, Kudo I, Komiyama K. Clinicopathological studies of odontoma in 47 patients. J Oral Sci 1999;41: 173-176. 30. MacDonald-Jankowski DS. Odontomas in a Chinese population. Dentomaxillofac Radiol 1996;25:186-192. 31. Kaffe I, Naor H, Buchner A. Clinical and radiological features of odontogenic myxoma of the jaws. Dentomaxillofac Radiol 1997;26:299-303.
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Odontogenic Tumours in Thailand Kittipong Dhanuthai Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Abstract Objective: This study was performed to determine the incidence of odontogenic tumours in the Thai population. Patients and Methods: The pathology records of 1020 patients with odontogenic tumours diagnosed at the Department of Oral Pathology, Chulalongkorn University, Thailand, during a 26-year period from 1977 to 2002 were reviewed and reclassified according to the World Health Organization 1992 criteria. Clinical data, including age, gender, and anatomical distribution of lesions, were also collected and analysed. Results: Odontogenic tumours accounted for 7.6% of all the oral and maxillofacial lesions (n = 13,472). Of these, 1010 patients (99%) had benign tumours and 10 (1%) had malignant tumours. Ameloblastoma, odontoma, and myxoma were the commonest lesions encountered. The mean age for benign odontogenic tumours was 30.0 years and for malignant lesions was 33.5 years, with the majority (54.1%) of odontogenic tumours presenting in the second and the third decades of life. Women outnumbered men for benign tumours, while the reverse was true for malignant tumours. Benign and malignant odontogenic tumours showed a predilection for the mandible, especially the posterior region. Conclusions: Odontogenic tumours are uncommon lesions in the Thai population. The data from this study show similar trends to those from Asian and African series with minor differences. Key words: Odontogenic, Retrospective, Thailand, Tumour
Introduction Teeth develop from a complex interaction between ectodermal and ectomesenchymal tissues. Remnants of these tissues are left behind in the jaws both during and after odontogenesis and can give rise to a heterogeneous group of odontogenic lesions. 1 According to the World Health Organization (WHO) Histologic Classification of Odontogenic Tumors, these tumours fall into 3 categories:2 • tumours originating from odontogenic epithelium without odontogenic ectomesenchyme • tumours originating from odontogenic epithelium with odontogenic ectomesenchyme, with or without dental hard tissue • tumours originating from odontogenic ectomesenchyme with or without odontogenic epithelium. Correspondence: Kittipong Dhanuthai, Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Henri-Dunant Road, Patumwan District, Bangkok 10330, Thailand. Tel: (66 2) 218 8582; Fax: (66 2) 218 8581; E-mail: [email protected]
166
There are numerous published reports of odontogenic tumours from North America, Africa, and Asia. However, there is little information pertaining to the incidence and distribution of odontogenic tumours in the Thai population. The purpose of this study was to determine the incidence and distribution of odontogenic tumours according to age, gender, and anatomical location of these lesions in the Thai population and to compare these data with other reported series.
Patients and Methods The pathology records of 1020 patients with odontogenic tumours diagnosed at the Department of Oral Pathology, Chulalongkorn University, Thailand, during a 26-year period from 1977 to 2002 were retrieved. Hematoxylin and eosin slides were reviewed and reclassified according to the WHO Histologic Classification of Odontogenic Tumors criteria of 1992. Clinical information, namely age, gender, and anatomical distribution of the lesions was collected from the biopsy records. For the purpose Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Dhanuthai
of anatomical location, the maxilla was divided into 3 regions: • anterior (midline to the distal surface of the canine) • middle (the mesial surface of the first premolar to the distal surface of the third molar) • posterior (tuberosity). Similarly, the mandible was divided into 3 regions: • anterior (midline to the distal surface of the canine) • middle (the mesial surface of the first premolar to the distal surface of the third molar) • posterior (angle, ramus, condyle, and coronoid process). Locations other than the aforementioned sites were recorded as ‘others’. Data collected were analysed by descriptive statistics.
Results Of 13,472 oral and maxillofacial lesions, 1020 patients (7.6%) had odontogenic tumours. Among these, 1010 (99%) were benign tumours and 10 (1%) were malignant tumours. The 3 most common odontogenic tumours in descending order of frequency were ameloblastoma (51.3%), odontoma (20.4%), and myxoma (8.2%). The most common tumour in the subcategory of tumours originating from odontogenic epithelium without odontogenic ectomesenchyme was ameloblastoma (51.3%). The most common tumour in the subcategory of tumours originating from odontogenic epithelium with odontogenic ectomesenchyme (with or without dental hard tissue) was odontoma (20.4%). The most common tumour in the subcategory of tumours originating from odontogenic ectomesenchyme with or without odontogenic epithelium was myxoma (8.2%). The distribution of various odontogenic tumours is presented in Table 1. The odontogenic tumours in this series were encountered over a wide age range, from 1 to 83 years. The mean age of patients with benign odontogenic tumours was 30.0 years, whereas that of patients with malignant odontogenic tumours was 33.5 years. 540 tumours (54.1%) occurred in patients in the second and third decades of life, with a peak incidence in the second decade (28.3%). The age distribution in this series is presented in Table 2. Among the benign odontogenic tumours, 575 (56.9%) were encountered in women and 434 (42.9%) were encountered in men, Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Number
Percent
Ameloblastoma
523
51.3
Ameloblastic fibroma
18
1.8
Ameloblastic fibro-odontoma
8
0.8
Ameloblastic odontoma
8
0.8
Adenomatoid odontogenic tumour
57
5.6
Cementoblastoma
18
1.8
Calcifying odontogenic cyst
34
3.3
Complex odontoma
134
13.1
Compound odontoma
74
7.3
Odontogenic myxoma
84
8.2
Odontogenic fibroma
29
2.8
Calcifying epithelial odontogenic tumour
20
1.9
Squamous odontogenic tumour
3
0.3
Malignant ameloblastoma
7
0.7
Ameloblastic fibrosarcoma
1
0.1
Odontogenic myxosarcoma
2
0.2
Total
1020
100
Table 1. Distribution of various odontogenic tumours.
a male to female ratio of 1:1.3. Among malignant odontogenic tumours, 7 (70.0%) were encountered in men and 3 occurred in women, a male to female ratio of 2.3:1. The gender distribution of odontogenic tumours is presented in Table 3. The anatomical distribution of each type of odontogenic tumour is summarised in Table 4. Overall, both benign and malignant odontogenic tumours showed a predilection for the mandible, especially in the posterior region. Ameloblastoma demonstrated a strong predilection for the mandible with the ratio of mandible to maxilla as high as 10.8 to 1. If individual tumours were considered separately, ameloblastic fibro-odontoma, ameloblastic odontoma, adenomatoid odontogenic tumour, calcifying odontogenic cyst, compound odontoma, squamous odontogenic tumour, and myxosarcoma occurred in the maxilla more often than in the mandible.
Discussion Odontogenic tumours are relatively uncommon lesions accounting for less than 3% of all the oral and maxillofacial lesions in most reported series.3-8 The few reports from Africa showed the frequency of odontogenic tumours to be roughly 30% of all oral and maxillofacial lesions.9,10 The frequency of 167
Odontogenic Tumours in Thailand Age (years) 0-9
10-19
20-29
30-39
40-49
50-59
60-69
70-79
80-89
Unknown
Mean
Ameloblastoma
9
84
130
113
87
55
28
8
2
7
34.21
Ameloblastic fibroma
4
9
4
1
0
0
0
0
0
0
15.61
Ameloblastic fibro-odontoma
1
5
1
0
0
1
0
0
0
0
17.75
Ameloblastic odontoma
0
6
0
0
1
1
0
0
0
0
21.50
Adenomatoid odontogenic tumour
1
35
17
1
3
0
0
0
0
0
19.21
Cementoblastoma
0
7
3
3
4
0
0
0
0
1
26.41
Calcifying odontogenic cyst
0
19
8
5
1
0
1
0
0
0
22.12
Complex odontoma
3
50
41
18
10
5
3
3
0
1
25.99
Compound odontoma
3
39
17
8
1
4
1
0
0
1
21.00
Odontogenic myxoma
6
20
21
14
9
6
3
4
0
1
30.29
Odontogenic fibroma
1
5
9
4
6
4
0
0
0
0
32.03
Calcifying epithelial odontogenic tumour
1
4
2
5
3
2
3
0
0
0
35.40
Squamous odontogenic tumour
0
0
0
2
1
0
0
0
0
0
39.00
Malignant ameloblastoma
0
0
2
2
2
1
0
0
0
0
37.00
Ameloblastic fibrosarcoma
0
0
1
0
0
0
0
0
0
0
20.00
Odontogenic myxosarcoma
0
0
1
1
0
0
0
0
0
0
28.00
Total
29
283
257
177
128
79
39
15
2
11
Table 2. Age distribution of odontogenic tumours. Male
Female
Unknown
Total
Male to female ratio
Ameloblastoma
251
271
1
523
1:1.1
Ameloblastic fibroma
6
12
0
18
1:2
Ameloblastic fibro-odontoma
5
3
0
8
1:0.6
Ameloblastic odontoma
2
6
0
8
1:3
Adenomatoid odontogenic tumour
16
41
0
57
1:2.6
Cementoblastoma
10
8
0
18
1:0.8
Calcifying odontogenic cyst
14
20
0
34
1:1.4
Complex odontoma
49
85
0
134
1:1.7
Compound odontoma
29
45
0
74
1:1.6
Odontogenic myxoma
32
52
0
84
1:1.6
Odontogenic fibroma
9
20
0
29
1:2.2
Calcifying epithelial odontogenic tumour
8
12
0
20
1:1.5
Squamous odontogenic tumour
3
0
0
3
NA
Malignant ameloblastoma
6
1
0
7
1:0.2
Ameloblastic fibrosarcoma
0
1
0
1
NA
Odontogenic myxosarcoma
1
1
0
2
1:1
Total
441
578
1
1020
Abbreviation: NA = not applicable.
Table 3. Gender distribution of odontogenic tumours.
odontogenic tumours (7.6%) in this study is slightly higher than in previous studies,3-8 probably because of the university hospital setting where referrals, especially for ameloblastoma, are received from many hospitals and private clinics. Another 168
explanation may be that many more (and possibly all) cases of reactive and inflammatory lesions in western Europe and North America are submitted for histopathologic examination than in other parts of the world. Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
Dhanuthai
Maxilla
Mandible
Others
Unknown
Maxillary: mandibular ratio
Anterior
Midline
Posterior
Anterior
Midline
Posterior
Ameloblastoma
26
36
6
162
399
175
11
3
1:10.8
Ameloblastic fibroma
2
2
0
6
14
1
0
0
1:5.3
Ameloblastic fibro-odontoma
4
3
1
0
4
1
0
0
1:0.6
Ameloblastic odontoma
2
3
2
2
1
0
0
0
1:0.4
Adenomatoid odontogenic tumour
35
17
1
11
9
0
1
1
1:0.4
Cementoblastoma
2
1
0
2
12
0
1
0
1:4.7
Calcifying odontogenic cyst
18
7
0
10
8
0
0
0
1:0.7
Complex odontoma
31
31
2
15
60
5
0
0
1:1.3
Compound odontoma
39
10
0
17
14
1
0
1
1:0.7
Odontogenic myxoma
20
19
4
17
33
8
4
3
1:1.3
Odontogenic fibroma
6
7
0
7
15
0
0
0
1:1.7
Calcifying epithelial odontogenic tumour
6
2
0
7
9
0
1
1
1:2
Squamous odontogenic tumour
2
2
0
0
0
0
0
0
NA
Malignant ameloblastoma
0
2
1
2
3
3
0
0
1:2.7
Ameloblastic fibrosarcoma
0
0
0
0
0
0
0
1
NA
Odontogenic myxosarcoma
0
1
1
0
0
0
0
0
NA
Abbreviation: NA = not applicable.
Table 4. Anatomical distribution of odontogenic tumours.
In this study, ameloblastoma ranked as the most common odontogenic tumour, similar to studies from Asia and Africa, but this was in contrast to studies from North and South America, which demonstrated that odontoma was the most common odontogenic tumour. The explanation for this disparity may be that most odontomas are asymptomatic lesions and the majority of people in developing countries in Asia and Africa do not undergo routine radiographic examination. Only when the lesion produces symptoms or disfigurement would they seek medical attention. Some odontomas are removed without being sent for histopathologic examination even though this is considered to be poor clinical practice. Fregnani et al also suggested that the discordant results in the frequency of ameloblastoma and odontoma in different studies might be due to the location where the data were collected.11 Normally, data collected from general hospitals showed a higher incidence of ameloblastoma than odontoma, while those from dental hospitals showed the opposite. These authors stated that ameloblastomas were diagnosed in dental schools, but treatments were often carried out in general hospitals.11 Lastly, geographic Asian J Oral Maxillofac Surg Vol 16, No 3, 2004
and ethnic factors might be another explanation for the differences.4 In this study, ameloblastoma accounted for 51.3% of all odontogenic tumours, which was comparable to those by Adebayo et al (54.0%),10 Komori (57.0%),12 Odukoya (58.5%),13 and Wu and Chan (59.4%).3 The age and gender distributions of ameloblastoma in the present study were in accordance with previous studies with only minor differences.14-21 For instance, ameloblastomas in the present study occurred almost equally between genders, while studies from China,22 India,23 Nigeria,10,18 and Switzerland24 showed a male predominance. Regarding the site of occurrence, ameloblastomas in the present study showed a strong predilection for the mandible (91.5%) with only 8.5% occurring in the maxilla. This figure was comparable to those from Asia20,22 and Africa,10 but lower than studies from Turkey25 (18.8%) and Switzerland (19.2%).24 The compound and complex odontomas combined represented 20.4% of all odontogenic tumours. This figure was comparable to that from 169
Odontogenic Tumours in Thailand
Turkey,25 and lies somewhere between those from China,22 Africa,10,13 and the American continent.4,5,7,8 Several studies showed that compound odontomas were more common than complex odontomas,22,26-29 which was in contrast to the present study and that of MacDonald-Jankowski.30 Most studies, including ours, reported that odontomas present in the second and third decades of life.26-30 The present study and that of Lu et al22 showed that compound odontomas occurred more than complex odontomas in younger patients, while Katz26 reported that compound and complex odontomas demonstrated a similar age distribution. In this study and others,10 both compound and complex odontomas showed a predilection for women, but a number of studies reported a nearly equal gender distribution.4,26,27,29 The anterior maxilla was the site of predilection for compound odontoma, as in previous studies, 4,26,30 whereas complex odontoma showed a predilection for the anterior maxilla and mandibular premolar-molar region as in the studies of MacDonald-Jankowski 30 and Mosqueda-Taylor et al.4 Odontogenic myxomas accounted for 8.2% of all the odontogenic tumours in this study. This figure was comparable with that from the Chinese study,22 higher than the North American studies,5,7 and lower than the African and Turkish studies. 13,25 Most myxomas in the present study were encountered in the second to fourth decades of life as in previous studies,22,31 and occurred in women more often than men as in other studies.4,7,10,25,31 Several studies, including ours, showed that myxomas preferentially occurred in the mandible, especially the posterior part.4,10,22,31 Malignant odontogenic tumours are rare in the Thai population, accounting for only 1.00% of all odontogenic tumours and 0.07% of all oral and maxillofacial lesions. The figure from this study was comparable to that of Gunhan et al25 (1.5%), but lower than those of Odukoya13 (4.84%) and Lu et al22 (6.1%). Most studies, including ours, showed that odontogenic carcinomas outnumber odontogenic sarcomas. The most common malignant odontogenic tumour in this study was malignant ameloblastoma and this is in agreement with Lu et al.22 Malignant ameloblastomas predominantly 170
occurred in men and in the mandible more often than the maxilla, as in the studies of Odukoya,13 Lu et al,22 and Gunhan et al.25 In conclusion, odontogenic tumours are uncommon oral and maxillofacial lesions. Ameloblastoma is the most common odontogenic tumour in the Thai population, as in most Asian and African series, but different from most North and South American series in which odontoma ranks as the most common odontogenic tumour. The incidence and distribution of patient age and gender, and site of predilection in the present study are in accordance with most Asian and African series with only minor differences. Malignant odontogenic tumours are extraordinarily rare oral and maxillofacial lesions in the Thai population, with odontogenic carcinoma outnumbering odontogenic sarcoma. The most common odontogenic carcinoma in the present study was malignant ameloblastoma. However, the number of malignant odontogenic tumours was too small to draw any meaningful conclusions regarding age, gender, and site of predilection for these lesions.
Acknowledgements I would like to thank all staff in the Department of Oral Pathology for their contributions to this research.
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