Abstract

Introduction: The 4^th edition of the World Health Organization (WHO) classification of head and neck tumors, released in January 2017, re-designated the keratocystic odontogenic tumor as the Odontogenic Kerato-Cyst (OKC). The subsequent 5th edition published in 2022 maintains essentially the same conceptual framework for odontogenic lesions. OKCs are now regarded as benign odontogenic cysts and represent approximately 10% of all odontogenic cysts. They originate from remnants of the dental lamina and are characterised by a cystic cavity containing desquamated keratin, lined by a thin, parakeratinised squamous epithelium. OKCs can occur across a wide age range but most frequently present in the third decade of life, with a slight predominance in males. Although they may arise in any tooth-bearing area, the mandible is affected more often than the maxilla, particularly the posterior body, angle and ramus. In our series, a few cases involved the anterior mandible and were detected incidentally on panoramic radiographs. Subsequent CBCT imaging clarified the extent of cortical involvement and internal architecture. In contrast, maxillary OKCs most frequently originate in the anterior region and third molar area. OKCs are notable for their locally aggressive behavior and relatively high recurrence rate, especially in syndromic cases. Multiple OKCs are a hallmark feature of Nevoid Basal Cell Carcinoma Syndrome (NBCCS), an autosomal dominant multisystem disorder. Radiological evaluation-particularly Computed Tomography (CT)-plays a central role in the diagnosis, characterization and management of OKCs. This pictorial review aims to illustrate the imaging characteristics of OKCs across different modalities and highlight key radiologic findings that aid in distinguishing them from other cystic and neoplastic odontogenic lesions.

Key points:a. Panoramic radiography is valuable for the initial evaluation of suspected OKCs.
b. CBCT is the preferred imaging modality for detailed assessment of OKCs.
c. The differential diagnosis should include ameloblastoma, dentigerous cysts and radicular cysts.
d. The presence of multiple OKCs is a major diagnostic criterion for NBCCS.

Keywords:Odontogenic keratocysts; Panoramic radiography; Computed tomography; Magnetic resonance imaging; Basal cell nevus syndrome