Prevalence of odontogenic tumors: A retrospective study of an institute of Rajasthan

Introduction

Odontogenic tumors are a heterogeneous group of lesions with variable clinical and pathohistological features. The biological behavior of these tumors includes hamartomatous proliferation, non-aggressive benign tumors, and aggressive and malignant tumors.^[1] There has been considerable interest in odontogenic tumors by oral pathologists, who have studied and categorized these tumors for decades. These tumors are 2.5% of all biopsied lesions in oral pathology.^[2], ^[3] Although many retrospective studies have been conducted all over the world but unanswered question still remain about the relative frequency and the incidence of certain odontogenic tumors.^[4] The geographical distribution of these lesions is variable. 2 Many studies in different part of the world have shown differences in the relative prevalence of these tumors.^[5] Various attempts at classification of these tumors have been published to define diagnostic criteria, given the diversity of lesions that may arise from odontogenic tissues.^[1] The first classification of these tumors was published in 1971, based on a 5-year joint effort coordinated by the World Health Organization (WHO).5 An updated edition of this classification was published in 1992.^[6] A new classification was proposed in 2005, which included the odontogenic keratocyst as a benign odontogenic tumor.^[7] The purpose of this study was to investigate the epidemiological behavior of this heterogeneous group of tumors across a 2 year period and to compare these data with those in the literature.

Materials and Methods

A retrospective study was made of cases of odontogenic tumors recorded at our institution between January 2021 to December 2022. All cases of all gender and age were included in this study. All cases who were diagnosed with odontogenic tumor were also included in this study.Data was analysed for gender, age, anatomical site and histological type in 30 histopathology reports. Bone related lesions were excluded from this study.

In case of recuurent tumors, where diagnosis were different in two slides , histological appearance of both were assesed and one common diagnosis was made and considered as single case. The diagnoses were reassessed and adapted to the 2005 WHO classification.7 After the sample was obtained, a database was generated using the SPSS (v. 13.0) statistics software and statsistical data was analysed. This study was granted permission by the Research Ethics Committee of our institution.

Result

Out of 30 cases, males show predominant cases 60% (18/30 cases) and females show 40% cases (12/30 cases). Male: female ratio is 1.5:1. ([Table 1])

According to age, the most involved age group was found to be of 11-20 years which showed highest number of cases (36.7%), followed by 21-30 years (20%), 0-10 years (16.7%), 51-60 years(10%). Equal number of cases were found in age group of 31-40 years and 41-50 years (6.6%) and least was found to be in 61-70 years(3.3%). No cases were found after age of 70 years. ([Table 2]). Out of 30 cases maximum cases were found to be involving mandible (60%) and 40% involving maxilla ([Table 3]).

Out of 30 cases, most frequent odontogenic tumor was found to be ameloblastoma (46.7%) followed by Keratocystic odnontogenic tumor (20%), Odontoma (13%), Calcifying epithelial odontogenic tumor (10.4%), Adenomatoid odontogenic tumor (6.7%) and least was found to be Myxoma (3%) as seen in [Figure 1].

Discussion

Literature showed numerous reports on incidence of odontogenic tumors from different parts of world. After studying these papers some conclusions were maid which are

Benign tumors are more common than malignant tumors.

Ameloblastoma, odontoma, CCOT, KCOT myxoma are common tumors among them.

Calcifying epithelial odontogenic tumor is relatively uncommon but hiigher incidence is found in Iranian and South Indian population.

[Table 1]) this finding has not been demonstrated study done by Mosqueda-Taylor et al.^[8] But studied done by Ahlfors et al,^[9] Mullapudi et al,^[10] Verkhede et al,^[11] Gill S et al,^[12] Luo HY et al,^[13] De costa et al, ^[14] Tawfik MA et al^[15] and Johnson NR et al^[16] showed male predominance.

The ameloblastoma was the most common tumor in this study (46.7%) ([Table 2]); its frequency is similar to other studies done by Oduyoka et al^[17] (58%), Lu et al.^[18] (59%), Mullapudi et al,^[10] Verkhede et al, ^[11] Gill S et al,^[12] Tawfik MA et al ^[15] and Adebayo et al.^[19] (48%). In our study, the frequency of ameloblastoma was higher in males (57.2%) ([Table 1]), as also seen in studies conducted in Nigeria^[19] and Turkey;.^[20] Studies done in Africa showed that the prevalence of this tumor is higher in the second to fifth decades of life,^[19], ^[21] and that they are located preferably in the mandible,^[18], ^[21] both of which were seen in our study also ([Table 2], [Table 3]).

As of 2005, a new classification included the odontogenic keratocyst as one of the odontogenic tumors, renaming it as a keratocystic odontogenic tumor. The reasons includes its clinical behavior, having high recurrence rate after simple enucleation, the histological appearance, and the presence of tumor markers like proliferating cell nuclear antigen (PCNA), Ki67, BCE2, matrix metalloproteinase (MMP) 2 and 9, and p53.^[22] This was found to be the second most prevalent lesion in this study (20%) ([Table 2]). However study done by Pandiar D et al^[23] had highest prevalence of KOT in their study, and also found that it is affecting mandible and vast majority affected posterior region including ramus and angle of mandible.

Reichart et al ststted in his study that the average age of initial diagnosis in industrialized countries is 39.1 years compared with 27.7 years from developing countries and hypothesized that ameloblastoma develops 10 to 15 years earlier in developing countries than in industrialized countries.^[24] Dodge proposed that this variation among countries may be due to the poor nutrition and healthcare in developin contries which leads to accelerated aging process.^[25]

Odontoma is considered to be a tumor-like malformation (hamartoma) rather than a true odontogenic neoplasm of dental tissue and this tumor accounts for the fourth most common tumor. This was the most common of these tumors in the Americas, as reported by Ochsenius et al. ^[26] Mosqueda- Taylor et al.^[3] and Daley et al.^[27] Odontomas are least frequent in Africans ^[6] and Chinese. ^[18] There were 4 cases of odontomas in our study (50%) ([Table 1]). The lower incidence of odontomas in Africans is probably due to the lack of symptoms in many of these lesions or by their genetic factors. ^[6] This neoplasm was diagnosed mostly in patients aged below 30 years. Some published papers have also reported that new odontomas are discovered up to the third decade of life.^[8], ^[14] Odontomas were more prevalent in the maxilla (75%) ([Table 3]) and has similar incidence in both males and females ([Table 1]); this is similar with findings of Ladeinde et al^[5] who also reported no sex predilection in their study but different to the findings of Santos et al.^[28] which showed higher incidence in females. This relative less number of cases of odontoma in our study is may be due to the fact that odontoma are usually asymptomatic and the patients do not seek medical assistance everytime. Furthermore, some cases may go to ENT specialists and thus all the excised specimen are not submitted for histopathological examination.

The incidence of the adenomatoid odontogenic tumor was 6.7% of all odontogenic tumors in our study ([Table 2]). Some papers have reported that this tumor is more frequently found in the maxilla ^[21], ^[28] and in female patients.^[21] ([Table 1]); these findings were different in our study in our study, in which 50% of these lesions were found in the maxilla and 50% in mandible ([Table 3]) and equally present in both males and female ([Table 1]), all in the second decade of life (2 cases) ([Table 2]).

The calcifying epithelial odontogenic tumor was seen in 3 cases (10.7%) ([Table 2]); there was a slightly higher incidence in males (66.7%) ([Table 1]), and 66.7% of these cases were in the mandible ([Table 3]). These findings are similar to those in most studies ^[28] except for Hiroyuki et al ^[21] report. This neoplasm is usually found accidentally in routine exams. ^[19]

It is essential to define the epidemiology of these tumors to improve our knowledge about their behavior, which allows us to optimize the diagnosis and therapy.

Limitation of this study is that it is a one institute study with limited number of cases in this region, more such study should be done with multi institute study to know incidence of odontogenic tumors in more details.

Conclusion

There is a slight predominance of odontogenic tumors in men and during the first decades of life; most of them occur in the mandible. Statistically significant differences among the variables histological type and symptoms were found. In India, specifically in this study, which was done in a region where population miscegenation is significant, there were some differences compared to published studies undertaken in other parts of the world.

Conflict of Interest

None as stated by authors.

Source of Funding

None as stated by authors.