Dental follicular hamartomas in the opercula of teeth delayed in eruption

Abstract

Background. Delay or failure of tooth eruption has been attributed to a number of systemic conditions or local factors. Odontogenic lesions of cystic, neoplastic, or hamartomatous origin occasionally may result in delayed eruption of teeth. However, odontogenic hamartomas that interfere with tooth eruption have received limited attention and their histogenesis, clinicopathologic features, nomenclature, and classification remain a topic of debate.Case report. A healthy, 14-year-old Caucasian male presented complaining of pain in the region of the mandibular left and right second molars for approximately 3 months. On examination, the soft tissues overlying the distal portions of the partially erupted teeth #18 and #31 appeared inflamed and a clinical diagnosis of pericoronitis was made. The opercula covering both teeth were excised and submitted for histopathologic evaluation. The biopsy revealed islands of odontogenic epithelium with squamous metaplasia and focal round calcifications in a dense connective tissue stroma, also demonstrating numerous stellate-type giant cells with 1 or 2 nuclei and occasional multinucleated giant cells interspersed between thick bundles of collagen fibers. Despite the overall similarity of these lesions with peripheral odontogenic fibroma (POdF), the association with the opercula of partially erupted permanent molars and the presence of numerous giant cells strongly supported a diagnosis of odontogenic hamartomatous lesions in a pericoronal location. Excision of the opercula allowed the uneventful eruption of both teeth.Conclusions. Odontogenic hamartomatous lesions present within the operculum may represent a common cause of delayed eruption of permanent teeth. We believe that these lesions exhibit an indolent nonneoplastic clinical behavior and should be distinguished from POdF based on clinicopathologic correlation. Identification of stellate-type and multinucleated giant cells, which are predominantly present in at least a subset of these hamartomatous lesions, may further facilitate their discrimination from neoplastic POdF. We propose the use of the pathologic term “dental follicular hamartomas,” which may be followed by the anatomic and clinical specification “in the opercula of teeth delayed in eruption.” Background. Delay or failure of tooth eruption has been attributed to a number of systemic conditions or local factors. Odontogenic lesions of cystic, neoplastic, or hamartomatous origin occasionally may result in delayed eruption of teeth. However, odontogenic hamartomas that interfere with tooth eruption have received limited attention and their histogenesis, clinicopathologic features, nomenclature, and classification remain a topic of debate. Case report. A healthy, 14-year-old Caucasian male presented complaining of pain in the region of the mandibular left and right second molars for approximately 3 months. On examination, the soft tissues overlying the distal portions of the partially erupted teeth #18 and #31 appeared inflamed and a clinical diagnosis of pericoronitis was made. The opercula covering both teeth were excised and submitted for histopathologic evaluation. The biopsy revealed islands of odontogenic epithelium with squamous metaplasia and focal round calcifications in a dense connective tissue stroma, also demonstrating numerous stellate-type giant cells with 1 or 2 nuclei and occasional multinucleated giant cells interspersed between thick bundles of collagen fibers. Despite the overall similarity of these lesions with peripheral odontogenic fibroma (POdF), the association with the opercula of partially erupted permanent molars and the presence of numerous giant cells strongly supported a diagnosis of odontogenic hamartomatous lesions in a pericoronal location. Excision of the opercula allowed the uneventful eruption of both teeth. Conclusions. Odontogenic hamartomatous lesions present within the operculum may represent a common cause of delayed eruption of permanent teeth. We believe that these lesions exhibit an indolent nonneoplastic clinical behavior and should be distinguished from POdF based on clinicopathologic correlation. Identification of stellate-type and multinucleated giant cells, which are predominantly present in at least a subset of these hamartomatous lesions, may further facilitate their discrimination from neoplastic POdF. We propose the use of the pathologic term “dental follicular hamartomas,” which may be followed by the anatomic and clinical specification “in the opercula of teeth delayed in eruption.”