Hyperplastic Dental Follicles Research Articles

Range and demographics of radiolucent jaw lesions in a New Zealand population

To determine the range and demographic features of radiolucent jaw lesions in a New Zealand population. Histopathology reports from the University of Otago School of Dentistry over a 20-year period were reviewed to identify radiolucent jaw lesions. Reporting characteristics where standardised over the time period. There were no clinical exclusive criteria and the samples represented a wide range of clinical presentation and treatment history from multiple providers. Data were analysed using SPSS. A total of 17, 038 specimens were submitted to the oral pathology diagnostic service of which there were 4983 radiolucent lesions that fulfilled the criteria to be included in the study. The full range of pathology was detected over the twenty-year period and the study showed that the five most common radiolucent jaw lesions were the periapical granuloma, radicular cyst, dentigerous cyst, hyperplastic dental follicle and odontogenic keratocyst, which they accounted for 79.6% of all radiolucent jaw lesions. The range and demographic features of radiolucent jaw lesions in a New Zealand population was similar to international trends.

Multiple calcifying hyperplastic dental follicles: comparison with hyperplastic dental follicles

Multiple calcifying hyperplastic dental follicles (MCHDF) is a rare disorder that is characterized by multiple impacted teeth and enlarged dental follicles that include calcifications. The current lack of information characterizing MCHDF impedes clinicians from making prompt differential diagnoses. We describe five cases of MCHDF and analyze their clinical and histopathological features in an effort to compare MCHDF with hyperplastic dental follicles (HDF) of singly impacted teeth. Our five cases of MCHDF were examined and clinically/histologically compared with data from 50 singly impacted teeth with HDFs. The five patients described in this study were all male. The pattern of impaction varied, but every second molar was impacted in all the patients. Alterations in the number of teeth, such as supernumerary or congenitally missing teeth were observed. Upon microscopic examination, most of the calcifications consisted of basophilic droplets that were fused to one another, and were surrounded by whirling spindle cells. Another type of calcification that was observed less frequently resembled woven bone. These features were consistent with three previously reported cases and observed in HDFs of 20 singly impacted teeth. While the average period of impaction and the time to reach some level of calcification in MCHDFs was shorter than in single calcifying HDFs, the calcification was more generalized in MCHDFs. This study indicates that MCHDF is a separate pathologic entity with exclusive male predilection and earlier calcifications, different to HDF. Further studies are needed to understand the etiology of MCHDFs to provide various options for treatment, and to clarify the mechanisms of eruption.

Downregulation of matrix metalloproteinases in hyperplastic dental follicles results in abnormal tooth eruption

In this study, we compared the gene expression profiles of non-syndromic hyperplastic dental follicle (HDF) fibroblasts and normal dental follicle (NDF) fibroblasts using cDNA microarrays, quantitative PCR, and immunohistochemical staining. Microarray analysis showed that several collagens genes were upregulated in the HDFos, including collagen types I, IV, VIII, and XI and TIMP-1, -3, and -4 (fold ratio > 2.0). In contrast, the expression of MMP-1, -3, -10, and -16 together with IL-8 was more than two fold downregulated. The differential expression of the genes encoding alkaline phosphatase, MMP-1, -3, -8, and IL-8 was confirmed by quantitative RT-PCR, while that of 24 HDFs and 18 NDFs was confirmed by immunohistochemical analysis. However, HDFs showed stronger expression of MMP-3 than NDFs (P < 0.001). Collectively, these results indicate that defective regulation of MMPs mediating connective tissue remodeling may be responsible for abnormal tooth eruption.

Migrating Third Molar: A Report of a Case

Pathologic migration is an abnormal change in the position of a tooth within the dental arch. There are many etiologic factors associated with this phenomenon, but the exact cause is often difficult to diagnose. The following is a report of a 42-year-old man exhibiting a unique form of bilateral migration of his mandibular third molars. He was asymptomatic and unaware of this occurrence. The morbidity to remove these teeth was deemed too great to justify extraction. Biopsy of the overlying tissue associated with a left-impacted third molar revealed no significant pathologic process other than inflammation and some hyperplasia within the dental follicle. Histologic-radiographic correlation was inconclusive in determining whether epithelium from pericoronal soft tissue involving the right third molar was from a hyperplastic dental follicle or a small dentigerous cyst. It is speculated that the ultimate cause of the migration of the third molars was severe, aggressive periodontal disease of the adjacent molars.

Multiple calcifying hyperplastic dental follicles

This article describes two additional examples of this unusual condition; two others were reported previously. The microscopic features are those of the hyperplastic dental follicles that occur in regional odontodysplasia. However, the teeth are not defective, as in regional odontodysplasia. This rare condition is sufficiently distinctive to be considered a pathologic entity.

Pathological Study of the Hyperplastic Dental Follicle.

Eleven specimens of hyperplastic dental follicles were studied clinicopathologically, with reference to the patient's sex and age at the time of diagnosis, site of the lesions, and histopathology. The patients comprised 6 males and 5 females with an average age of 15.7 years (range 10 to 23 years). Two cases involved multiple lesions, and 9 a single lesion. The lesions were related to impaction of the canine, second premolar, second molar or third molar. Radiographically, the lesions showed various degrees of radiolucency around the crown of the impacted tooth. Most of the cases were diagnosed clinically as dentigerous cyst. The histopathological features of the lesions were similar to those of normal dental follicular tissue around the developing tooth. No tumorous features such as odontogenic fibroma, odontogenic myxoma or myxofibroma were evident in the lesions.

The central odontogenic fibroma: an attempt at clarification.

Three different but probably related central lesions of the jaws have been referred to previously as odontogenic fibromas. They are (1) hyperplastic dental follicles, (2) a fibrous neoplasm having a histologic appearance similar to that of a dental follicle, and (3) a more complicated lesion, illustrated in a WHO publication, consisting of fibrous connective tissue with varying amounts of odontogenic epithelium, dentin, and/or material resembling cementum. The terms simple odontogenic fibroma and odontogenic fibroma (WHO type) are proposed, respectively, for lesions 2 and 3 above. Some examples of lesion 3 may be confused histologically with the calcifying epithelial odontogenic tumor. More information is required on the biologic behavior of both 1 and 2. A central fibroma of the jaws should be considered a desmoplastic fibroma if it does not appear to have arisen from the odontogenic apparatus and is not a neurofibroma.