Jaw bone cysts were initially described by Fauchard in 1728 as intra-osseous pathological cavities filled by fluids, semi-solid, or gaseous material, partially or completely covered with epithelial cells, and surrounded by a capsule of connective tissue. When a cyst develops from odontogenic epithelial remnants, it is referred to as an odontogenic cyst [1-3]. The odontogenic cysts are the unique lesions that affect the oral and maxillofacial tissues. They develop as a result of inflammatory and/or developmental pathogenic processes related with the tooth-forming apparatus epithelium [4, 5]. These cysts are characterized by slow-growing and expanding. Despite being benign, they can grow to critical size if not diagnosed or treated early . Numerous consensus meetings have attempted to provide a more systematic classification of these lesions, as promoted by the World Health Organization in 1971, taking into account various odontogenic cysts . The other WHO meetings in 1992, 2005, and 2017 changed the classifications of these lesions . In the 3rd edition of the odontogenic lesions classification, published in 2005, odontogenic keratocysts and calcifying odontogenic cysts were classified as neoplasm tumors and given the names keratocystic odontogenic tumours (KCOT) and calcifying odontogenic cystic tumors (COCT), respectively. However, the debate about odontogenic tumors subtypes persisted. In 2017, the WHO revised its categorization of odontogenic tumors, redesignating KCOT, and COCT as developing odontogenic cyst keratocysts, and calcifying odontogenic cysts, respectively . Recently, the 5th edition of the World Health Organization (WHO) classification of Head and Neck Tumors (HNT) was released in March 2022. This edition is not conceptually very different from the previous classification of odontogenic lesions. The classification of odontogenic cysts, which was removed in the third edition of 2005 and added in the fourth edition of 2017, is maintained in the current fifth edition with the same entities . Although there are numerous researches about odontogenic cysts in the literature, little is known about the demographics and behavioral patterns of the Iraqi population.
This study aims to investigate the prevalence of odontogenic cysts in the Iraqi population during 11 years and compare findings with those from other different geographical areas.
Materials and Methods
This retrospective cross-sectional study was conducted between 10. 11. 2021 to 05.05.2022 after ethical approval was obtained from the Ethical Committee in the College of Dentistry, University of Baghdad (Ref.: 125, 28.11.2019). All (3992) recodes of the oral biopsies at the pathological laboratory in the College of Dentistry, University of Baghdad were checked and the odontogenic cysts samples had been isolated. The diagnosis of odontogenic cysts was confirmed by examining the histopathological picture in each case by two pathologists using light microscope according to the latest criteria of the WHO published in 2022. Demographic data and histopathological findings of the patients were retrieved from their case sheets. The ages and sex of the patients and the location of each lesion were noted. All case records were reevaluated to be classified according to the latest criteria of the WHO published in 2022 . Two sites were determined: the maxillary area and the mandibular region, regardless of the side and exact position.
The descriptive statistical analyses were performed with IBM SPSS for Windows Version 21.0 package program (IBM Corp released in 2012). Numerical variables were summarized with the mean, and standard deviation (MSD). Categorical variables were given in numbers and percentages.
Results and Discussion
Three hundred and sixty-eight patients out of 3992 patients were diagnosed as the odontogenic cysts. The frequency of odontogenic cysts was 10.8% of total biopsied specimens. When the results of the present study were compared with the results of the other studies from different countries (Table 4), it was found that the studies from Mexico , India , Brazil [11, 12], Greece , and Iran [14, 15] reported similar frequencies ranging between 6.8% and 17.7%. Studies from Turkey , Brazil , and Kenya  reported the higher frequencies for odontogenic cysts (Table 1). According to the WHO classification, the radicular cyst diagnosed in 212 patients (57.61%), followed by keratocyst 66 (17.93%), dentigerous cyst 57 (16.03%), calcifying odontogenic cyst 19 (5.16%), and Glandular odontogenic cyst 6 (1.63%) (Table 2). Therefore, the most common type of odontogenic cyst in this study was radicular cysts. Similar results were found in most of the previous studies of different countries [18-26], while odontogenic keratocyst was the most predominant in the Brazil study . Furthermore, Butt et al. reported that dentigerous cysts (31%) were the most common type of odontogenic cysts, followed by radicular cysts (22%) in Kenya  with slight differences. Furthermore, Baghaei et al. identified dentigerous cyst (27.2%) as the most common odontogenic cyst and radicular cyst (18.6%) as the 2nd in Iran . According to the age of patients, it differs from 6 years old to 80 years old, with a mean of 32.4 ± 16.4. The present study revealed that the odontogenic cysts mainly occurred in the 2nd and the 3rd decades of life, which is in line with studies from Mexican , Brazilian , Indian , and Iranian populations . Furthermore, of the 368 odontogenic cyst patients, 222 (60.33%) were males and 146 (39.67%) were females. With a male-to-female ratio of about 1.52:1 (Tables 2 and 3), which was consistent with research performed in other countries, including Portugal, Brazil, Mexico, Italy, India, Kenya, Greece, Turkey, Italy, and Iran (ranging between 50.9 % and 64.4 %) [9-25]. In contrast, female predominance was significant in the Brazilian population  and among Indonesians . These variances in frequency, gender, and age may be attributable to the fact that the majority of these studies classified odontogenic keratocyst and calcifying odontogenic cyst as neoplasms rather than cysts, as well as genetic and socioeconomic factors that influence the prevalence of inflammatory cysts, Moreover, the higher male prevalence may be due to poor oral hygiene and greater trauma susceptibility. On the other hand, this study revealed that odontogenic cysts mainly were located in the mandible (52.89%) similar to the other previous studies . The OC site distribution revealed that the maxilla was exaggerated in 182 (49.46%) cases while the mandible was in 186 (50.54%) cases. The most common site of radicular cysts was the maxillary area. On the other hand, odontogenic keratocysts (68.18%) and dentigerous cysts (54.24%) were more frequent in the mandibular area (Table 4).
The current study evaluated the demographic and histopathological features of odontogenic cysts in a sample of Iraqis between 2011 and 2021 in a leading center of oral and maxillofacial pathology in Iraq. The findings revealed that male patients in their second and third decades have the highest prevalence of odontogenic cysts, particularly in the mandibular region. The current data analysis provides more information
on the demographic distribution and clinical aspects of odontogenic cysts in the Iraqi population.
The authors would like to express their sincere gratitude to the Oral and Maxillofacial Pathology Laboratory staff at the College of Dentistry, University of Baghdad for their kind assistance throughout the study.
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
All authors contributed to data analysis, drafting, and revising of the paper and agreed to be responsible for all the aspects of this work.
Conflict of Interest
There are no conflicts of interest in this study.
Haider H. Al-Qazzaz
Bashar H. Abdulllah
Omar S. Museedi
HOW TO CITE THIS ARTICLE
Haider H. Al-Qazzaz, Bashar H. Abdulllah, Omar S. Museedi. Clinicopathological Analysis of Odontogenic Cysts in Iraqi Population. J. Med. Chem. Sci., 2023, 6(4) 891-897