Clinicopathological Evaluation of Odontogenic Jaw Cysts

a. Assistant Professor & Head, Department of Oral & Maxillofacial Surgery, Update Dental College & Hospital b. Junior Consultant, Department of Dental Surgery, BIRDEM General Hospital, Shahabag, Dhaka-1000. c. Junior Consultant, Brahmanbaria Medical College & Hospital. d. Junior consultant, Department of ENT, Jalalabad Ragib Rabeya Medical College & Hospital, Sylhet. e. Junior Consultant, Shahabuddin Medical College & Hospital, Gulshan, Dhaka.


Conclusion:
The most frequently occurring lesion was radicular cyst and the site was the anterior region of the maxilla.The dentigerous cyst and odontogenic keratocyst were the next most common lesions and preferred site was in the ramus and angular region of the mandible.

Introduction:
A cyst is a pathological fluid, semi-fluid or gaseous-filled cavity lined by epithelium that, in turn, is lined by a capsule of connective tissue.They deserve one's attention, mainly because of all the complications they can originate, such as facial aesthetic changes, jaw fractures, infections, and occasional neoplasia of its epithelium 1 .Many classifications of jaw cysts have been proposed and used, according to different criteria such as its embryologic origin, aetiology, or its clinical-morphological manifestations.
The World Health Organization (WHO) more recently, classifies epithelial cysts (or true cysts), as odontogenic cysts and non-odontogenic cysts.The first type includes two categories: inflammatory and developmental.Non-odontogenic cysts are also developmental cysts and include nasopalatine and nasoalveolar cysts, amongst others.Cysts without epithelial lining, also called pseudo-cysts, are nowadays considered to be non-neoplastic bone lesion and include solitary bone cysts and aneurysmal bone cysts 1, 2. Odontogenic cysts are one of the most common osseous-destructive lesions affecting the jaws.These cysts arise from the epithelial components of the odontogenic apparatus or its remnants that lie entrapped within bone or in the gingival tissue.They are classified traditionally into a developmental group, including keratocysts and dentigerous cysts.The most recent classification of the World Health Organization (WHO) reallocated keratocyst (keratinized primordial cyst) within the classification of maxillary tumours under the term "keratocystic odontogenic tumour" (KOT).Its slow, expansible and noninfiltrating growth pattern constitutes clear evidence of its benign nature -a situation which may facilitate late diagnosis 2, 4, 5, 8, 9, 13, 14- 18. Odontogenic keratocysts (OKCs) are common, clinically aggressive lesions that are thought to arise from the dental lamina or its remnants.The most characteristics clinical aspect of odontogenic keratocysts (OKCs) is the high frequency of recurrence.The mechanism of recurrence is thought to be related to residues of cysts epithelium and an intrinsic growth potential following excision 3, 6, 7, 10 11, 12, 19, 20, 21. .Developmental odontogenic cysts and inflammatory odontogenic cysts are epithelial lesions, characterized by a slow growth and an expansible tendency and in spite of being entities which present a benign biological behavior, they can reach considerable size if they are not diagnosed in time and treated appropriately.Since a number of cystic lesions of the jaws share similar clinical and radiographic features, the diagnosis of odontogenic cysts usually requires a detailed analysis of clinical, radiographic, and histopathologic findings 2, 4.11,12,14, 22-25.Materials and Methods: This was a cross-sectional, observational study conducted with 62 patients having odontogenic cyst of the jaw.The total period of study was from 1 st March' 2010 to 28 th February '2011.The study was undertaken at inpatient and outpatient department of Oral and Maxillofacial Surgery, Bangabondhu Sheikh Mujib Medical University, Shahabag, Dhaka.Eligible Patient came with cystic lesion in the mandible or maxilla was included in the study.After taking informed consent, data were collected by history, clinical examination, radiological and histopathological examination.The following variable were recorded: gender, age, site of the lesion, swelling, tooth obility, carious tooth, discolored tooth, missing tooth, radiological features of the lesions and associated with impacted teeth and correlating with histological types After the patient had given consent to be included in the study, a standardized structured data collection sheet was used to collect necessary information of the study subject.The data were screened and checked for any missing value and discrepancy.The data were then analyzed by using Microsoft Excel.Data were interpreted accordingly and were presented in tables, chart and bar diagrams.

Results and Observation:
The study was conducted in the department of Oral and Maxillofacial Surgery, BSMMU, Dhaka.The study was intended to determine the frequency of different types of odontogenic jaw cysts diagnosed among the Bangladeshi population. .A total of sixty-two patients were included.After collection of data, the data were assessed carefully and meticulously.Then it was entered in the computer for analysis.The data were then analyzed by using Microsoft Excel.Data were interpreted accordingly and were presented in tables, chart and bar diagrams.Table-4: Shows that 56% (n=35) cyst were located in the maxilla and 44% (n=27) cyst were located in the mandible.In the maxilla 48% (n=30) were located in anterior part and 8% (n=5) were located in posterior part.In the mandible 12% (n=7) were located in anterior part and 32% (n=20) were located in posterior part.In the maxilla 48% (n=30) were located in anterior part and 8% (n=5) were located in posterior part.In the mandible 11% (n=7) were located in anterior part and 33% (n=20) were located in posterior part.Also shows that among the radicular cyst 42% (n=26) located in the anterior maxilla and in case of dentigerous cyst & odontogenic keratocyst the common site was posterior mandible.were males and 43% were females 4,5 .Similarity found in other studies 8-12, 14, 16 .Radicular cysts are lesions which are produced as a consequence of pulpar necrosis and therefore, are considered to be of an inflammatory nature.In this study found that the radicular cysts represent 56% (n=35) of all odontogenic cysts, being the most frequent of all these lesions in relative terms; this finding is similar to that of Kavita  3,5 .Others support the present study 9,10,11,12,13,14  With respect to anatomic location, most odontogenic cysts affected the maxilla 56% (n=35) and 44% (n=27) in the mandible.In the maxilla 48% (n=30) were located in anterior part and 8% (n=5) were located in posterior part.In the mandible 12% (n=7) were located in anterior part and 32% (n=20) were located in posterior part.The most frequent location of inflammatory cysts (radicular and residual cysts) was the maxilla, and for developmental cysts (keratocysts and dentigerous cysts) was the mandible, mainly in the posterior sector.These results are similar to those obtained by Luis Monteiro et al.Who as for the location of the cysts 53.3% of all cysts were on the maxilla and 46.5% were on the mandible.In the maxilla, the most affected sector was the anterior (59.7%), whereas in the mandible, the most affected sector was the posterior (81.5%), those of Kavita Rao et al.Who found, the maxilla (59%) was more commonly involved than the mandible (41%) 1,2 .The majority of cysts were detected in the anterior maxilla followed by the posterior mandible.In anterior maxilla, radicular cysts were more common.Odontogenic keratocyst was more common in the posterior mandible [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][22][23][24][25] .

Conclusion and recommendation
The present results showed a similar frequency of prevalence of odontogenic cysts when compared to other similar studies, with inflammatory cysts being identified as the most frequent odontogenic cyst.The most frequently occurring lesion was radicular cyst and the site was the anterior region of the maxilla.The dentigerous cyst and odontogenic keratocyst were the next most common lesions and preferred site was in the ramus and angular region of the mandible.Knowledge of the biological and histological behaviour of odontogenic cysts and their frequency are key aspects for ensuring early detection and adequate treatment.It is recommended that a detail history, thorough clinical examination and radiological evaluation are mandatory for the diagnosis and better management of odontogenic jaw cysts.