ABSTRACT
Tooth impaction is a frequent phenomenon, and the prevalence and distribution of this entity in different regions of the jaws may vary considerably. The third molars, maxillary canines, maxillary and mandibular premolars, and maxillary central incisors are the most commonly affected teeth. Impacted teeth in children and adolescents are rarely associated with pathological changes, but the prevalence of problems has been found to increase in later decades. Impacted teeth are commonly asymptomatic and not associated with any pathologic lesions for years. Proliferative potential of various odontogenic lesions were calculated using Ki-67 labeling index calculation, with the highest index of Unicystic Ameloblastoma followed by Adenomatoid odontogenic tumor, Unicystic Ameloblastoma, followed by the dental follicle. Ki-67 is a marker of cell proliferation, used as an important diagnostic marker in the pathologic differentiation of various lesions. It is always better to orthodontically treat or extract asymptomatic impacted teeth to avoid or to restrict the proliferative capacity of the dental follicle. Treatment decisions about the third molar have important clinical and cost implications.
ABSTRACT
BACKGROUND: Indistinct and analogous histopathological features of various fibro-osseous lesions make establishing a definitive diagnosis a challenge. There is a need for additional molecular and histochemical tools to support and differentiate these lesions in order to establish a concrete diagnosis. MATERIALS AND METHODS: A retrospective analysis of biopsied lesions in formalin-fixed paraffin-embedded sections (10 cases each of fibrous dysplasia, ossifying fibroma, and cement-osseous dysplasia) retrieved from the archives was studied for immunoexpression of osteocalcin (quantitative analysis in osteocytes), collagen characterization using Azan, Picrosirus, and Toluidine blue stain for evaluating intensity and localization of collagen fibers, and morphometric analysis of vasculature (for evaluating mean vessel density as square microns). RESULTS: Positive immunostaining of osteocalcin suggested mutations of the GNAS-1 gene found in fibrous dysplasia indirectly, as it is a negative regulator of bone formation. Osteocalcin immunopositivity was quantitatively measured in the fibro-osseous lesions, with fibrous dysplasia measuring 14.47 ± 3.628 as compared to ossifying fibroma measuring 5.23 ± 1.33, followed by cemento-osseous dysplasia measuring 2.30 ± 1.409. Toluidine blue suggests the presence of oxytalan fibers (resistant to acid hydrolysis) in ossifying fibroma and cemento-osseous dysplasia, pointing toward the pathogenesis of the lesion. Azan stain and Picrosirus (under a polarizing microscope) helped in distinguishing hard tissue characteristics (70% of cases of fibrous dysplasia showed only a magenta component followed by intermixed magenta with a blue component in 20% of cases and only 10% of cases showed magenta with blue borders whereas for ossifying fibroma, 40% of cases depicted magenta with blue borders along with the other 40% with intermixed magenta with blue component). The mean vessel density was also highest in fibrous dysplasia measuring 7.90 ± 1.079 (in Sq. micron area), followed by ossifying fibroma and cemento-osseous dysplasia. CONCLUSION: The diagnosis of fibro-osseous lesions by hematoxylin and eosin alone is confusing and thus should be supported by relatively simple histomorphometric analysis for better treatment outcomes. At the diagnostic stage of fibro-osseous lesions, evaluation of intralesional vessel size, reliable molecular marker, and histochemical nature can aid in differentiating fibrous dysplasia from central ossifying fibroma and cemento-osseous dysplasia alongside, other clinical, radiographic and pathological criteria. These parameters help in the diagnostic decision-making of fibro-osseous lesions.
