Early soft tissue pathosis associated with impacted third molars without pericoronal radiolucency

Correlation Between Angular Position and Pathological Changes in Impacted Lower Third Molars: A Systematic Review and Meta-Analysis

Background: The extraction of impacted third molars presents anatomical challenges and surgical risks, prompting debate over prophylactic removal, particularly for impacted lower molars. Studies highlight associated pathologies and complications that influence treatment decisions. Objective: This study aims to systematically review and analyze the correlation between the angular positions of impacted lower third molars and their association with pathological changes, including periodontal defects, alveolar bone loss, and cystic degeneration. Methods: This systematic review was conducted according to PRISMA guidelines, including studies from 2000 to 2024. Studies reporting the angular position and associated pathologies of impacted lower third molars were included. The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias. A meta-analysis of the proportion of pathological changes related to specific angular positions was performed. Results: Of the 2943 studies initially identified, six studies (including 2222 patients and 3276 impacted lower third molars) met the inclusion criteria and were included in the review, while four studies were included in the proportional meta-analysis. The most common angular positions observed were mesioangular (34.0-66.1%), followed by vertical (12.8-48.3%), horizontal (8.1-23.4%), and distoangular (3.2-14.0%). Pathological changes were reported in 8.1-75.0% of cases, with horizontal impactions demonstrating the highest correlation (41.1%, 95% CI: 20.9-63.0). Conclusions: The angular position of impactions of the lower third molars significantly influences the risk of pathological changes. Horizontal impactions exhibit the highest associated with pathological changes, whereas distoangular impactions show the lowest prevalence of complications. Standardized diagnostic and reporting practices are needed to improve clinical decision-making. Further research should focus on long-term outcomes and the impact of clinical management strategies.

Radiographic identification of symptomless mandibular third molars without clinical pericoronitis

OBJECTIVES

The aim was to identify radiographic characteristics of mandibular third molars in young adults without symptoms or clinical signs of pericoronal infection.

MATERIALS AND METHODS

An existing cross-sectional material, including records from clinical oral examination and panoramic radiographs (PANs) of university students, was submitted to retrospective analysis. The outcome variable was a symptomless and clinically pericoronitis-free mandibular third molar. Predictor variables for the third molar were clinical eruption level, pathological signs in the follicle, marginal bone level, radiographic depth in bone, inclination, stage of root development, and available space for eruption. Statistics included χ2 and Mann-Whitney U tests.

RESULTS

Analysis included 345 mandibular third molars in 189 participants (20% men, 80% women; mean age 20.7 years; SD ± 0.6). Symptomless and clinically pericoronitis-free mandibular third molars were characterized as follows: clinically unerupted in 78% of teeth, associated with reduced marginal bone level in 70%, located deeper in the bone in 87%, mesially inclined in 73%, and stage of root development incomplete in 68% (p ≤ 0.001 for all).

CONCLUSIONS

Radiographic characteristics of symptomless mandibular third molars without clinical pericoronitis in young adults can be assessed from a PAN with 68-87% certainty.

CLINICAL RELEVANCE

These findings may prove useful when trying to exclude non-pathological mandibular third molars from diseased teeth.

Prophylactic third molar removal: are oral surgeons and orthodontists aligned in preventive approaches?

BACKGROUND

There is a general consensus among dental professionals regarding the extraction of impacted third molars in the presence of clinical symptoms. However, there is less agreement on the management of asymptomatic third molars. The objective of this study is to compare the perspectives of oral surgeons and orthodontists regarding the indications for the extraction of asymptomatic third molars. It is possible that healthcare professionals from different specialties may approach the extraction of these teeth in different ways.

METHODS

In this cross-sectional study, a web-based questionnaire has been employed to collect data by inquiring about the reasons why participants prefer the extraction of asymptomatic third molars. Descriptive statistics were employed to evaluate the data obtained. The level of significance was set at P < 0.05.

RESULTS

Prophylactic extraction of partially impacted molars was more favored among the participants (P < 0.05). The orthodontists preferred prophylactic extraction due to the risk of late anterior dental crowding (LADC); however, the oral surgeons preferred pre-pregnancy extractions (P < 0.05). The extraction decision for partial impaction was higher in females when the risk of distal caries was considered. For fully impacted ones, it was higher in males when the risk of caries and pericoronitis were considered (P < 0.05).

CONCLUSIONS

Orthodontists preferred extraction because of the risk of LADC and caries, while oral surgeons focused on preventing pericoronitis, pathology, focal infection, and symptoms during pregnancy. This divergence between the participants may inform the guidelines for prophylactic management of third molars. These findings may be pertinent in gender medicine.

CLINICAL RELEVANCE

This study has been enlightening for departments to consult each other before the extraction of a patient's asymptomatic third molar.

Histopathological Changes of Dental Follicles of Impacted Third Molars in Ibb Governorate

OBJECTIVE

There is a lack of data pertaining to the examination of dental follicles (DFs) in asymptomatic impacted lower third molars (ILTMs) using cone beam computed tomography (CBCT) and histopathological analysis in the Yemeni population. The objective of this study was to explore the DFs of asymptomatic ILTMs through radiological (CBCT) and histological analysis.

MATERIALS AND METHODS

This prospective study comprised 60 patients aged 18-50 years with ILTMs. The ILTMs in these patients exhibited a DF with measurements ranging between 3 and 5 mm. CBCT was employed to evaluate the maximum width of the DF surrounding the crown of ILTMs in horizontal, sagittal, and coronal sections. After the extraction, the DFs were examined for any pathological changes and categorized as normal, inflammatory, cystic, or neoplastic. The data analysis was performed using IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States), and the statistical significance was determined by employing chi-square tests with a significance level of 0.05.

RESULTS

In the study, a total of 60 patients were included, with 17 (28.3%) being male and 43 (71.7%) being female. The majority of the patients 26 (43.3%) fell within the age range of 26-35 years. Regarding the angulation of the ILTMs, most of them were mesioangular 45 (75%), followed by vertical 7 (11.7%), horizontal 4 (6.6%), buccoangular 3 (5%), and distoangular 1 (1.6%). Histopathological changes were observed in 44 of the samples (73.3%). The majority of histopathological changes identified in the DFs were dentigerous cysts 26 (59%) followed by odontogenic keratocysts 11 (25%). Thirty-six (81.8%) of histopathological changes were found in females, whereas in only eight samples (18.1%), histological changes were observed in males. This difference was statistically significant (p=0.004). However, there were no statistically significant differences observed in the occurrence of histopathological changes based on age, angulation, and follicle size (p>0.05).

CONCLUSION

Follicles in ILTMs varied significantly based on gender, with a higher occurrence in females, and tooth impaction angle, mainly in the mesioangular position. Furthermore, a follicular size of 3-5 mm was associated with a higher incidence of pathological changes. Hence, histopathologic examination is recommended for surgically removed ILTMs irrespective of the follicle size observed in radiographic images.

An Observational Study on Cystic Alterations in Normal Dental Follicles Associated with Impacted Lower Third Molar for Early Intervention

AIM

To evaluate the cystic changes in the radiographically normal dental follicle associated with impacted mandibular third molar.

MATERIALS AND METHODS

This study was conducted on 80 patients. Samples were selected using a convenient sampling technique from the patients who had impacted mandibular third molars in Pell and Gregory's positions B and C, with follicular space less than 2.5 mm in diameter. After surgical removal of an impacted tooth, the dental follicle was sent for histopathologic evaluation.

RESULTS

Pathologic alterations were found in 19% of cases out of 80 samples. Odontogenic keratocystic and dentigerous cystic changes were found in 7% of cases. A statistically significant cystic alteration was found in female patients and distoangular impacted teeth.

CONCLUSION

This study shows a significant cystic alteration in the radiologically normal dental follicles. Clinical and radiographic features alone may not be a reliable indicator of the absence of pathology. Early intervention of impacted teeth will help to reduce morbidity due to the development of pathology.

CLINICAL SIGNIFICANCE

This study will help educate patients on the risks of retaining impacted teeth, based on scientific facts, in order to minimize the risks and to assess the correlation of pathologic alterations with the depth of impaction and angular position of the impacted tooth.

Early pathological changes of peri-coronal tissue in the distal area of erupted or partially impacted lower third molars

AIM

This study was performed to histologically evaluate peri-coronal tissues of partially impacted and erupted third molars that did not exhibit pathologic peri-coronal radiolucency.

MATERIALS AND METHODS

Healthy patients with erupted or partially erupted (with part or all of the dental crown present in the oral cavity) mandibular third molars (classified as IA and IIA according to the Pell and Gregory classification) and vertically positioned (according to the Winter classification or erupted third molars) associated with peri coronal radiolucency of equal to or less than 2.5 mm. Associated with third molar surgery, tissue sampling from the distal area was performed, which was subjected to an anatomopathological examination to determine the histological nature.

RESULTS

One hundred teeth (100 patients) were selected, and 100 specimens were analyzed. 53% of the sample were included in the non-pathological group and 47% showed pathological changes (fibrotic tissue (n 15), periodontal cyst-like (n 9), squamous epithelial metaplasia (4 cases), islands of odontogenic epithelial residues organized micro-cyst with keratocystic/ameloblastic appearance (4 cases), granulation tissue (n 8), giant cell tumour (n 4) and lobular capillary hemangioma (n 4)). Pathological changes did not have differences in incidence between the gender (p value = 0.85) and did not show any correlation with age, (p value = 0,96).

CONCLUSIONS

These findings suggest that radiographic appearance may not be a reliable indicator of the absence of disease within a dental follicle. Therefore, clinicians should pay attention to or follow up on even peri-coronal radiolucency of less than 2.5 mm.

Evaluation of the follicular space volume of lower third molars with different impaction positions and angulations: A cone-beam computed tomography and histopathological study

Objective

To quantify the volume of the follicular spaces of impacted lower third molars (ILTMs) with different impaction positions and angulations using cone-beam computed tomography (CBCT) and to determine its association with the histopathological findings.

Study design

This study included 103 ILTMs of 33 men and 70 women aged 18-46 years (mean age, 29.18 years). The follicular space volumes were measured on CBCT by manual segmentation and correlated with the histopathological diagnosis of each ILTM having different impaction positions and angulations. Statistical Product and Service Solutions, version 24, was used for statistical analyses by applying the t-test and binary logistic regression and multiple linear regression tests (p < 0.05).

Results

Overall, 83 (80.6%) dental follicles presented a non-pathological diagnosis (mean follicular volume, 0.10 cm³), whereas 20 (19.4%) presented a pathological diagnosis (mean follicular volume, 0.32 cm³; p = 0.001). Similarly, the impaction depth in Position C cases was associated with a pathological diagnosis (p = 0.010).

Conclusion

The follicular volume of the ILTMs varied significantly in teeth with a histopathological diagnosis of a follicular cyst and was associated with the impaction depth, mainly in Position C cases, and its relationship with the mandibular ramus. A mean follicular volume of 0.32 cm³ was associated with a greater probability of a pathological diagnosis.

The radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars

OBJECTIVES

The indication for removal of asymptomatic fully impacted third molars is still controversial. In this study, radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars was performed, aiming to provide a reference for clinical prophylactic extraction of these teeth.

METHODS

Patients with impacted mandibular third molars were included and the maximum width of the dental follicle around the crown was measured in horizontal, sagittal and coronal sections by cone beam computed tomography. The dental follicles were stained with haematoxylin-eosin, analysed by a pathologist and classified as normal, inflammatory or cystic. A Chi-squared test was used to analyse the association of the incidence of inflammation and cysts with the clinical variables of the impacted mandibular third molars.

RESULTS

Thirty-seven samples were normal dental follicles; 52 samples showed inflammatory infiltration with an incidence of 57.14%; 2 samples with a maximum dental follicle width of 2-3 mm were diagnosed as odontogenic cysts, and the incidence was 2.20%. There was no significant difference in the incidence of inflammatory and cystic dental follicles between males and females, or between different age groups (P > 0.05). With an increase of the maximum width of the dental follicle, there was a rise in the incidence and degree of infiltration of chronic nonspecific inflammation.

CONCLUSION

Asymptomatic impacted mandibular third molars tend to be extracted, especially for teeth with a 2-3 mm maximum width of the dental follicle on radiological examination.

Correlation Between Radiographic and Histopathologic Findings Associated with Unerupted Teeth in Dogs

An association between unerupted teeth and dentigerous cysts is well known,^{1- 4} however little is known about the presence of disease and histopathologic changes in unerupted teeth without radiographic evidence of cyst formation. Forty-two dogs representing 25 breeds, ranging in age from 5 months to 12 years were selected based on radiographic evidence of an unerupted tooth or teeth, either as a primary complaint or incidental finding. Dogs meeting the study criteria were presented to a private dental referral practice within a period of eighteen months from December 2016 through May 2018. Patients were treated with conservative en bloc resection of the unerupted tooth and overlying bone as well as debridement of any cystic structure and biopsy of the samples collected. Radiographs were evaluated using criteria previously established to assess for evidence of a cyst.^{1, 5- 7} A total of 68 unerupted teeth were identified; 63 (92.7%) were mandibular first premolar teeth. Of the 63 unerupted mandibular first premolar teeth, 28 (44.4%) had radiographic evidence of a cystic structure. Histopathology revealed that 21 of 28 (75.0%) had evidence of non-keratinizing stratified squamous epithelium consistent with a cyst lining. Of the remaining 35 of 63 (55.6%) mandibular first premolar teeth with no radiographic evidence of a cyst, 27 (77.1%) had no histologic evidence of epithelium associated with the impacted tooth. Notably however, the remaining 8 of 35 (22.9%) unerupted teeth without radiographic evidence of a cyst did have histologic evidence of non-keratinizing stratified squamous epithelium associated with the impacted tooth.

Non-coding RNAs transcribed from ultra-conserved regions (T-UCRs) are differentially expressed in dental follicle tissues of impacted mandibular third molars

INTRODUCTION

Transcribed ultra-conserved regions (T-UCRs) are a new class of long non-coding RNA molecules transcribed from ultra-conserved regions (UCRs) of the human genome. T-UCRs are extremely conserved in the human, rat, and mouse genomes. Deletions of genomic areas containing UCRs resulted in live mice that developed without discernible phenotypes, implying that T-UCRs are involved in developmental processes. In addition, there is increasing evidence that dental follicle tissues exhibit various cellular alterations involving deregulation of protein-coding genes and non-coding RNAs. Accordingly, the main objective of the present study was to determine the clinical significance and distinct expression signatures of non-coding RNA molecules transcribed from ultra-conserved regions in dental follicle samples.

MATERIALS AND METHODS

From March 2021 to December 2022, a total 42 patients who referred to clinic of oral and maxillofacial surgery department with the indications of impacted mandibular third molar extraction from 38^th and 48^th positions were enrolled for the study. For the analysis of T-UCR expression levels, real-time quantitative reverse transcription PCR method was used.

RESULTS

Findings of the present study indicated that T-UCRs are distinctly expressed in dental follicle tissues of impacted mandibular third molars. The expression of uc.38, uc.112, and uc.338 was found to be significantly increased in the dental follicles of impacted mandibular third molars, indicating a clinical significance of these molecules. In addition, no differences in T-UCR expression were found as a function of demographic factors.

CONCLUSIONS

Collectively, transcribed ultra-conserved elements, such as uc.38, uc.112, and uc.338, are considerably deregulated in the dental follicle tissues of impacted mandibular third molars and might be responsible for the molecular changes acquired by dental follicle tissues of impacted mandibular third molars.

Investigation of the expression level of long non-coding RNAs in dental follicles of impacted mandibular third molars

OBJECTIVES

Dental follicle (DF) is made up of mesenchymal cells and fibers surrounding the enamel organ of a developing tooth. It has been shown that cystic and neoplastic lesions can develop from the pericoronal follicles of impacted third molars (ITMs). But the molecular transformation of DF tissues has not yet been uncovered and remains elusive. Accordingly, in the present study, we aimed to investigate the differential expression of lncRNA genes in DF tissues associated with asymptomatic impacted mandibular third molars (IMTMs) that do not show pathological pericoronal radiolucency in radiographic examination.

MATERIAL AND METHODS

A total of 30 patients with unilateral mesioangular IMTMs were enrolled for the study. The expressions of lncRNA genes were determined in the DF and healthy gingival tissues obtained from study patients. For the determination of lncRNA expression levels, RNA was isolated from the obtained tissues, converted to cDNA samples, and analyzed by quantitative real-time PCR method.

RESULTS

As a result, we found that the gene expression of MEG3 was increased about 10-fold in DF tissues compared to healthy gingival tissues (p < 0.0001). In addition, NORAD expression was found to be upregulated 4.2-fold (p = 0.0002) in DF tissues. Also, expression level of MALAT1 was found to be decreased 1.24-fold (p = 0.584) and TP73-AS1 increased 2.6-fold (p = 0.093) in DF tissues compared to healthy gingival tissues.

CONCLUSIONS

Consequently, present findings suggest that differentially expressed lncRNAs in DFs might be associated with the various levels of cellular events including osteogenic differentiation, DNA damage, and the transformation into odontogenic pathology.

CLINICAL RELEVANCE

Expression levels of MEG3 and NORAD lncRNA molecules may guide clinicians in the evaluation of asymptomatic ITM dental follicles that cannot be determined radiologically and during extraction of these teeth for prophylactic purposes.

Revisiting the human dental follicle: From tooth development to its association with unerupted or impacted teeth and pathological changes

Dental follicles are involved in odontogenesis, periodontogenesis, and tooth eruption. Dental follicles are unique structures, considering that their remnants can persist within the jawbones after odontogenesis throughout life if the tooth does not erupt. Pathological changes may occur in these tissues as individuals age. The changes range from benign to life threatening. Thus, the assessment of age-related changes in dental follicles associated with unerupted teeth is of paramount importance. In this review, we summarize the physiological roles and changes in dental follicles in odontogenesis, tooth eruption, and aging, in addition to the pathological changes associated with these structures. We encourage investigators to consider this peculiar tissue as a unique model and explore its potential to clarify its importance from the viewpoints of developmental biology, tissue physiology, and pathology.

Age-Related Metabolic Pathways Changes in Dental Follicles: A Pilot Study

Aging is not a matter of choice; it is our fate. The “time-dependent functional decline that affects most living organisms” is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology.

What factors differentiate dentigerous cysts from other pericoronal lesions?

OBJECTIVE

To evaluate the histopathologic outcomes of pericoronal radiolucencies and identify factors predictive of diagnosis.

STUDY DESIGN

A retrospective cohort study of 258 patients with 280 radiolucent pericoronal lesions undergoing treatment at our institution between 2005 and 2019. The primary predictor variable was lesion size (≥2 cm and <2 cm). The primary outcome variable was histopathologic diagnosis (dentigerous cyst vs other pathologic entity). Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between clinical and radiographic variables and histopathologic diagnosis.

RESULTS

The study sample was composed of 258 patients with 280 histopathologic specimens. There were 218 dentigerous cysts (77.9%) and 62 other pathologic entities (22.1%). Lesions ≥2 cm were 3.20 times more likely to be diagnosed as a nondentigerous cyst pathologic entity (P ≤ .001). After adjusting for jaw (maxilla vs mandible), pain, history of infection, cortical perforation, expansion, and multiple lesions, younger age (P ≤ .001, odds ratio [OR] = 0.950, 95% confidence interval [CI] = 0.929-0.972) and lesion size as a continuous variable (P = .007, OR = 1.06, 95% CI = 1.02-1.11) were independent predictors of other pathologic entities.

CONCLUSIONS

The majority of pericoronal radiolucent lesions were dentigerous cysts. Younger age and larger lesions were independent predictors of other pathologic entities.

Effects of aging on DNA hydroxymethylation and methylation in human dental follicles

OBJECTIVE

Despite the high frequency of impacted teeth and increased frequency of lesions in dental follicles (DF) with aging, DF age-changes remain unclear. We compared the global methylation and hydroxymethylation profiles in DF in relation to age.

DESIGN

DF associated with impacted lower third molars were obtained from 59 individuals. Global DNA methylation (5mC content) and hydroxymethylation (5hmC) were evaluated by ELISA. We tested the correlation between 5mC and 5hmC content, and the correlation of each with patients' age. The differences in age, 5mC, and 5hmC in DF from men/women, and location (left/right mandible) was tested.

RESULTS

The mean age of the 59 individuals was 19.56 ± 3.92, ranging from 13 to 31 years, and most were women (n = 39). 5hmC content and age up to 19 years were inversely correlated (Spearman's correlation coefficient=-0.552, p = 0.0003, n = 38). There was no relationship between 5hmC and 5mC content. There was no difference in the medians of age (p = 0.25), 5hmC (p = 0.33) and 5mC (p = 0.86) between men/women, nor in the medians of age (p = 0.39), 5hmC (p = 0.99) and 5mC (p = 0.22) between the left/right side of the tooth extraction.

CONCLUSION

An inverse correlation between 5hmC and age was established, with no correlation between 5mC and 5hmC content in DF. The biological meaning of such a decrease of global DNA hydroxymethylation with age in DF remains to be clarified.

Prevalence of Pathologies Associated with Impacted Third Molars in Kosovar Population: an Orthopanthomography Study

Objective

The aim of this study was to evaluate the prevalence of pathologies associated with impacted third molars radiographically noticeable in a Kosovar population, as currently no data are available.

Methods and Materials

This was a retrospective study of 5515 panoramic images of patients who visited the University Dentistry Clinical Center of Kosovo. Of these 5515 patients, 2368 were males and 3147 were females. The age range was from 18 to 77 years. We reviewed panoramic images in order to determine the number of pathologies associated with impacted third molars. The following radiographic lesions were recorded: caries of impacted teeth and/or adjacent tooth, root resorption of adjacent tooth, periodontal bone loss of adjacent tooth of more than 5mm below the cemento-enamel junction and an increase in pericoronar gap over 4mm.

Results

The prevalence of pathologies associated with impacted third molar in Kosovar population was 29.5%. Root resorption of adjacent tooth had the highest frequency of pathology 307 (23.7%). It was followed by periodontal bone loss of adjacent tooth of more than 5 mm 71 (5.5%) and caries 33 (2.5%). The lowest was an increase in pericoronar gap 15 (1.2%).

Conclusion

The most common pathology was root resorption, with the highest incidence of pathology localized in the maxilla 159 (32.3%). The prevalence of periodontal bone loss, caries and increase in pericoronar gap was significantly lower. The findings of our research could have an impact on development of prevention strategies that will proficiently deal with pathologies that result from impacted teeth.

Tridimensional assessment of the dental follicle dimensions of impacted mandibular third molars using cone-beam CT

Background

The present study was performed to compare follicle dimensions of impacted mandibular third molar (IMTM) with different impaction angulations using cone beam computed tomography (CBCT).

Material and Methods

Forty-nine individuals with IMTM (24 male, 25 female) were selected. Their age range was 25-55 years. The sample was divided into three IMTM groups either vertical (n=16), mesioangular (n=18) or horizontal (n=15) position based on Winter’s classification (the angle between the longitudinal axis of the second and third molars). Follicular spaces (FS) from available CBCT imaging were measured from the midpoint of the teeth’s crown in several dimensions (mesial, distal, occlusal, apical, vestibular and lingual) in axial, sagittal and coronal planes. An ANOVA, T-student, Kruskal–Wallis and Mann-Whitney U tests were used.

Results

A comparison of the mesial FS for all groups revealed significant differences (p<0.001). Significant difference was also found for vestibular FS between the vertical and mesioangular IMTM groups (p=0.04). Buccolingual FS for all groups revealed no significant differences (p=0.074), whereas significant difference was found for the vertical and horizontal IMTM groups (p=0.02). No significant statistical differences were found for occlusal (p=0.54), apical (p=0.06), and lingual (p=0.64) FS.

Conclusions

In this sample IMTM follicles have different dimensions according to their degree of angulation. Mesioagulated and horizontally positioned IMTMs seems to consistently have some increased FS dimensions (mesial and vestibular aspects).

Key words:Dental follicle, impacted tooth, third molar, cone-beam computed tomography.

Study of Pathological Changes in the Dental Follicle of Disease-Free Impacted Third Molars

Background

The prophylactic extraction of third molars is a common practice in dental offices, but divergent opinions are found in the literature regarding the indication of this procedure. The aim of the present study was to determine the prevalence of pathological changes associated with the pericoronal tissue of asymptomatic impacted third molars that could justify prophylactic extraction.

Materials and Methods

A cross-sectional observational study was conducted in which 109 pericoronal tissues with no radiographic evidence of pathology were histopathologically analyzed. The specimens were fixed in 10% formalin, embedded in paraffin, stained with hematoxylin and eosin and analyzed individually by two pathologists.

Result

The frequency of inflammatory infiltrate in the dental follicle of patients older than 20 years of age was significantly higher than that of younger patients (p = 0.004), demonstrating an association between inflammation in the dental follicle and patient age. The occurrence of squamous metaplasia was also greater in patients older than 20 years (p = 0.042), demonstrating that the prevalence of squamous metaplasia increases with age. A significant association was also found between inflammation and squamous metaplasia (p < 0.001).

Conclusion

Pathological changes may be present in the dental follicle of impacted third molars even in the absence of clinical or radiographic signs of disease.

Dentigerous Cystic Changes in the Follicles Associated with Radiographically Normal Impacted Mandibular Third Molars

Objective

To assess the incidence of dentigerous cystic changes in the follicles of radiographically normal impacted mandibular third molars.

Methods

One hundred and thirteen follicles obtained after surgical removal of impacted mandibular third molars with radiolucency of less than 2.5 mm in the radiograph were sent for histopathologic evaluation to evaluate pathologic changes.

Results

The incidence of dentigerous cystic changes observed was 15.9%, that is, 18 out of 113 patients (51 males and 62 females), with the maximum incidence of cystic changes seen in the follicular space size of 0.5 mm. The mean age of the patients included was 27.8 ± 8.1. The most common indication for extraction among the patients in this study was recurrent pericoronitis (95%). There were no statistically significant differences in occurrence of cystic changes based on age, gender, angulation, relation to ramus, depth, side of impaction, and follicle size (P > 0.05).

Conclusion

Dental follicles obtained from surgically removed impacted mandibular third molars should be submitted for histopathologic examination irrespective of the radiographic size of the follicle.

Histopathological Evaluation of Dental Follicle Associated with Radiographically Normal Impacted Mandibular Third Molars

Introduction

Removal of impacted mandibular third molar is a common procedure performed in oral surgery. Indications for removal of the third molar have generated much discussion in dentistry. The presence of pericoronal pathosis is generally accepted reason for the extraction of impacted mandibular third molars. Radiographic pathology is usually defined as a pericoronal radiolucency measuring about 2.5 mm or larger in any dimension.

Purpose

This study aims to evaluate the histopathologic changes in radiographically normal dental follicles associated with impacted mandibular third molars.

Methods

After extraction of 50 impacted mandibular third molars, dental follicle associated with extracted teeth was placed in 10% formalin solution. Histopathologic examination was done. The type of pathological changes was recorded based on histopathological reports. Patients' gender, age, and radiographic parameters were recorded.

Results

Cystic changes were found in 24% of radiographically normal impacted mandibular third molars. Significant cystic changes were observed in position A vertically impacted lower third molars (ILTMs). Male predominance for cystic change was seen with a male-female ratio of 2:1.

Conclusion

The result of the present study shows that radiographic analysis may not be reliable technique for the diagnosis of cystic changes in ILTM. The presence of cystic changes can be found even in radiographically normal impacted mandibular third molars. Hence, we recommend that impacted mandibular third molars should be removed and histopathological analysis should be conducted on all surgically extracted dental follicles.

P53 Protein Expression in Dental Follicle, Dentigerous Cyst, Odontogenic Keratocyst, and Inflammatory Subtypes of Cysts: An Immunohistochemical Study

OBJECTIVES

An odontogenic keratocyst (OKC) is a developmental odontogenic cyst with aggressive clinical behavior. This cyst shows a different growth mechanism from the more common dentigerous cyst and now has been renamed as a keratocystic odontogenic tumor (KCOT). Inflammation can assist tumor growth via different mechanisms including dysregulation of the p53 gene. This study aims to assess and compare the expression of tumor suppressor gene p53 in inflamed and non-inflamed types of OKC and dentigerous cyst.

METHODS

Immunohistochemical expression of p53 was assessed in 14 cases of dental follicle, 34 cases of OKC (including 18 inflamed OKCs), and 31 cases of dentigerous cyst (including 16 inflamed cysts).

RESULTS

The mean percentage of p53 positive cells was 0.7% in dental follicles, 5.4% in non-inflamed OKCs, 17.3% in inflamed OKCs, 1.2% in non-inflamed dentigerous cysts, and 2.2% in inflamed dentigerous cysts. The differences between the groups were statistically significant (p < 0.050) except for the difference between inflamed and non-inflamed dentigerous cysts, and between dental follicle and non-inflamed dentigerous cyst.

CONCLUSIONS

The difference in p53 expression in OKC and dentigerous cyst can explain their different growth mechanism and clinical behavior. Inflammation is responsible for the change in behavior of neoplastic epithelium of OKC via p53 overexpression.

Incidence of Radiographic Cystic Lesions Associated With Unerupted Teeth in Dogs

Medical records and radiographs were retrospectively reviewed over a 3-year period (2012-2015) from dogs presented to a private dental referral practice. Medical records were evaluated for the diagnosis of impacted or embedded teeth. The identified dogs’ radiographs were reviewed for the presence of radiographically significant cystic lesions that were associated with the impacted or embedded teeth. Radiographic criteria were established by the authors for the purposes of identifying cystic lesions in dogs of different breeds and sizes, using established indices from human dental pathology as a basis. When histopathology results were available, they were reviewed and reported. In this study, 136 dogs ranging in age from 3 months to 17 years were diagnosed with 213 unerupted teeth during the study period. There were 62 (29.1%) of the 213 radiographically apparent cystic lesions identified based on the criteria proposed in this study. In this study, 146 (68.5%) of the 213 unerupted teeth were identified as mandibular first premolar teeth. Histopathology was obtained on 28 (45.1%) of the 62 diagnosed cystic lesions. Dentigerous cysts accounted for 20 (71.4%) of the 28 cystic lesions. Brachycephalic breeds were overrepresented in this study. Boxer, pug, Shih Tzu, and Boston terrier dogs were most likely to present with cystic lesions associated with unerupted teeth. Seventeen (85%) of the 20 cases with a histopathologic diagnosis of dentigerous cyst were found within these 4 brachycephalic breeds.

Calcifying Cystic Odontogenic Tumor in Radiologically Normal Dental Follicular Space of Mandibular Third Molars: Report of Two Cases

Two cases of calcifying cystic odontogenic tumor (CCOT) of the dental follicle in an impacted third molar without clinical and radiological evidence are reported during routine histopathological examination. In both the cases left mandibular third molar was mesioangularly impacted with pericoronal radiolucency of less than 2.5 mm, which was not indicative of any pathology. As a routine protocol (which is not practiced widely) of our institution, dental follicles associated with extracted molars were sent for histopathological examination. Histopathological features were consistent with CCOT with pathognomonic ghost cell transformation of odontogenic epithelium. The patients were followed for one year with no recurrence. This paper emphasizes the importance of routine histopathological examination of dental follicles associated with asymptomatic impacted teeth without any clinical or radiographic evidence of follicular lesion.

Prevalence of pathologies related to impacted mandibular third molars

OBJECTIVE

Prevalence of cysts and tumors related to impacted third molars has been considered important because the risk justifies prophylactic extraction. This retrospective study aimed to evaluate the prevalence of cysts or tumors associated with impacted mandibular third molars (IMTMs) according to patients' age and gender.

METHODS

Over the period from August 2006 to August 2011, 20,802 third molars from 17,535 patients were removed. Among these, IMTMs without cysts nor tumors were classified as non-pathology group, and IMTMs with cysts and tumors were classified into pathology group. The prevalence of IMTMs and associated cysts or tumors was analyzed in patient groups stratified by age and gender. The pathology group patients were also classified according to histopathological findings and the corresponding age groups.

RESULTS

Radiographic signs of disease were detected for 176 lesions (0.846 %) in 165 patients. Of these, 135 (76.4 %) lesions were diagnosed as dentigerous cysts, 31 (17.6 %) as keratocysticodontogenic tumors, and 10 (5.7 %) as ameloblastomas. The prevalence of cysts or tumors tended to increase after 50 years of age, such as 7.27 % in 6th decades, 18.60 % in 7th decades, and 11.53 % in 8th decades, with a male predominance in older patients.

CONCLUSIONS

IMTMs in old age patients more than 50 years old has high possibilities of developing cyst or tumors especially in male patients. However, these results should not be used as the only evidence for justifying prophylactic extraction, and further studies should investigate the survival rate of IMTMs without any pathologic in older populations.

Incidência de anormalidades histológicas em tecido correspondente ao espaço pericoronário de terceiros molares inclusos e semi-inclusos

INTRODUÇÃO: O Folículo Pericoronário envolve a coroa do germe dental durante seu desenvolvimento. Quando o dente permanece incluso, alterações do folículo podem originar doenças, como cistos e tumores odontogênicos. OBJETIVO: Analisar as alterações histológicas no tecido mole circundante a terceiros molares inclusos e semi-inclusos, independentemente de alterações patológicas aparentes em suas radiografias correspondentes, além de relacionar o diagnóstico histológico com o diagnóstico radiográfico dos casos. MATERIAL E MÉTODO: A partir de terceiros molares extraídos de 26 pacientes, foram analisados espécimes histológicos de folículos pericoronários por dois examinadores calibrados. O diagnóstico histopatológico obtido foi relacionado ao radiográfico, sendo este realizado por meio de radiografias periapicais e, quando necessário, complementado por radiografias panorâmicas. RESULTADO: Dos 37 folículos pericoronários avaliados, 30% mostraram alterações histológicas compatíveis com cistos dentígeros; 51% eram folículos normais, e 19% continham apenas fragmentos de mucosa. Radiograficamente, 100% dos casos demonstraram características de folículos sem alterações. CONCLUSÃO: Esses dados exemplificam que anormalidades podem estar presentes nos tecidos pericoronários sem que haja evidências clínicas e radiográficas. O exame histopatológico provê um diagnóstico mais preciso e deve ser considerado para a construção do diagnóstico definitivo.

Quantitative and qualitative analysis of epidermal growth factor receptor expression in pericoronal follicles in predicting proliferative potential

OBJECTIVE

The odontogenic epithelium in pericoronal follicles (PFs) are known to proliferate to form cysts and tumors. This epithelium is mostly composed of the reduced enamel epithelium (REE) and odontogenic rests (OR). The objective of the present study was to evaluate the epidermal growth factor receptor (EGFR) immunoexpression in these PFs to assess their proliferative potential.

STUDY DESIGN

The immunoexpression of EGFR in 30 PFs were assessed by two independent observers for intensity, percentage and the location of the EGFR staining.

RESULTS

EGFR immunoexpression was noted in 100% of the follicles. A greater proportion of the follicles showed strong intensity (70%). It was noted that nearly 54% of the follicles demonstrated more than 50% of cells with EGFR immunolabelling. EGFR showed combined cytoplasm and membrane staining (40%) and cytoplasm only staining (37%). The analysis of the REE and OR individually for the above-mentioned parameters did not show statistical significance.

CONCLUSION

The increased intensity and overall positivity of the epithelium in follicles shows that odontogenic epithelium is responsive to EGFR mediated growth factors. The predominant combined staining pattern is suggestive of increased potential for the epithelium to undergo cystic or neoplastic proliferation.

Immunohistochemical analysis of Ki-67 in dental follicle of asymptomatic impacted third molars

INTRODUCTION

Dental follicle (DF) is an ectomesenchymal tissue that surrounds the developing tooth germ and contains precursor cells for cementoblasts, periodontal ligaments and osteoblasts. Radiographically, the DFs are seen as semicircular radiolucencies around unerupted teeth. However, if the DFs are larger than 2.5 mm, they are considered to be a pathological change.

AIMS AND OBJECTIVES

The purpose of this study is to assess the cell proliferation activity of DF surrounding an asymptomatic impacted third molar teeth using the Ki 67 proliferation marker and to evaluate the variation of cell proliferation depending on the age factor.

MATERIALS AND METHODS

Forty-four specimens of DFs associated with impacted mandibular third molars fully covered by mucosa or bone were surgically removed from 44 patients. The patients were divided into 2 age groups. Twenty of forty-four DFs were between 18 and 29 years (Group 1) and 24 were 30 years and above (Group 2). Ki-67 immunostaining was evaluated in epithelial component of the DFs.

RESULTS

Ki 67 expression was found to be 60% in Group 1 and 75% in Group 2. Statistically significant differences were found among the two groups in both the basal layer and the supra-basal layer.

CONCLUSION

This study shows that DFs have more proliferative potential in older people as compared to the young and squamous metaplasia may be an early sign of developing lesions of odontogenic origin. Therefore, clinicians should be aware that histopathological changes could be found in DFs without clinical and radiographic alterations.

Analysis of the immunoexpression of Ki-67 and Bcl-2 in the pericoronal tissues of impacted teeth, dentigerous cysts and gingiva using software image analysis

BACKGROUND

Pericoronal tissue is the soft tissue located between the bony crypt and the impacted tooth, which is histologically composed of fibrous connective tissue and is usually lined by the reduced enamel epithelium. Increased epithelial cell proliferation in the pericoronal tissue is associated with pathological changes such as development of an odontogenic cyst or an epithelial odontogenic tumor. This study is an attempt to evaluate and compare the proliferative index in the epithelium surrounding the impacted third molar teeth, dentigerous cysts, and gingiva.

MATERIALS AND METHODS

A case control study on pericoronal tissues and dentigerous cysts was carried out using immunomarkers. Forty pericoronal tissues were obtained from asymptomatic impacted third molars with pericoronal radiolucency less than 2.5 mm. Samples of 20 dentigerous cysts and normal gingiva were also included. Routine hematoxylin and eosin and immunostaining for Ki-67, a cell proliferation marker and Bcl-2, an anti apoptotic protein were performed on sections of pericoronal tissues, dentigerous cysts, and gingival tissues. The percentage of Ki-67-positive cells and Bcl-2 positive areas was found using the DigiPro™ version 4.0 Image analysis software. Bcl-2 immunopositivity and Ki-67-Li were analyzed using the Chi-square test and paired t-test. P- values of less than .05 were considered to indicate statistical significance.

RESULTS

The immunohistochemical analysis revealed overexpression of Bcl-2 in the pericoronal tissues with squamous metaplasia, which was comparable to the dentigerous cyst. Ki-67 Li of the pericoronal tissue with squamous metaplasia was equal to the proliferative index of the dentigerous cyst. The expression of Ki-67 Li and inflammatory cells were highly significant (P < 0.0001).

CONCLUSIONS

The results of this study indicate that the pericoronal tissues of asymptomatic impacted third molars may be actively proliferating and normal pericoronal radiolucency cannot serve as an indicator for the differentiation potential.

The relation of pericoronal third molar follicle dimension and bcl-2/ki-67 expression: An immunohistochemical study

Background:

Most common impacted teeth are the mandibular third molars and decision about extraction of them is usually controversial. The presence of pericoronal pathologic changes is an acceptable reason for removal of impacted teeth. Differences in the proliferation rate and apoptosis of odontogenic epithelial cells may influence on the formation of odontogenic epithelial lesions. Therefore, the aim of the present study is to evaluate the immunohistochemical expression of the bcl-2 apoptosis-inhibiting protein and the cell-cycle-related ki-67 antigen in pericoronal follicle of impacted third molars with ≥2.5 mm and <2.5 mm radiolucency.

Materials and Methods:

This was a cross-sectional study that 20 follicles with <2.5 mm radiolucency and 20 follicles with ≥2.5 mm radiolucency were selected by a professional radiologist in digital panoramic radiographs and then referred to a surgeon. Formalin fixed paraffin-embedded tissues were immunohistochemical analyzed for immunoreactivity of bcl-2 protein and ki-67 antigen. The data was analyzed using logistic regression, Spearman correlation coefficient and t-test and Mann-Whitney. P<0.05 was considered significant.

Results:

The findings showed correlation between size of the third molar's follicles and expression of bcl-2 protein (P < 0.001, r = 0.556) but there was no correlation between size of third molar's follicles and staining with ki-67 antigen (P = 0.546, r = 0.098). The follicles with radiolucency ≥2.5 mm showed increased immunoreactivity for bcl-2 protein.

Conclusion:

The results of study suggest that impacted third molars with radiolucency ≥2.5 mm may be associated with deregulation of cell death, indicated with increased expression of the anti- apoptotic protein bcl-2, while cell proliferation (ki-67) does not seem to play a significant role.

Histopathologic evaluation of follicular tissues associated with impacted lower third molars

CONTEXT

Previous studies have reported that the dental follicular tissues associated with impacted lower third molars (ILTMs) may undergo cystic degeneration and/or neoplastic transformation. This is especially likely when the pericoronal space is >2.5 mm on intraoral radiographs and >3 mm on panoramic radiographs and to examine dental follicular tissue for pathological changes in patients with ILTMs and pericoronal radiolucencies of <2.5 mm.

AIM

Histopathological evaluation of follicular tissues associated with ILTMs.

MATERIALS AND METHODS

The morphology of the hematoxylin and eosin-stained follicular tissues of 146 such impactions were studied.

RESULTS

On microscopy, no cystic structures with fibrous walls were identified. 85 cases (58%) showed fibrous or myxomatous connective tissue and no epithelial elements. 61 cases (42%) showed epithelial elements in addition to fibrocollagenous tissue. Of these, 16 cases exhibited epithelium, of which 13 cases showed reduced enamel epithelium and three cases showed squamous metaplasia/non-keratinized stratified squamous epithelium.

CONCLUSIONS

All asymptomatic unerupted third molars with pericoronal radiolucency of <2.5 mm should be retained since they do not exhibit cyst formation microscopically.

Clinicopathological evaluation of 164 dental follicles and dentigerous cysts with emphasis on the presence of odontogenic epithelium in the connective tissue. The hypothesis of "focal ameloblastoma"

Objectives: Some ameloblastomas presumably originate from odontogenic epithelium within the connective tissue of dental follicles and dentigerous cysts. Therefore, it would seem reasonable to discuss as whether odontogenic epithelium proliferations, frankly displaying ameloblastomatous features (“focal ameloblastoma”), should be considered as an “early” ameloblastoma. Study Design: Histopathological reports from 164 dental follicles and dentigerous cysts from the Department of Oral and Maxillofacial Surgery/Oral Pathology of the VU Free University medical center in Amsterdam, The Ne-therlands, were reviewed. Histopathological slides from 39 cases reporting the presence of odontogenic epithelium within the connective tissue were re-evaluated in order to assess the possible presence of focal ameloblastomas. Results: Focal ameloblastomas were detected in one dental follicle and in two dentigerous cysts. During a follow-up period of 6, 8 and 22 years, respectively, no clinical signs of (recurrent) ameloblastoma have occurred in these patients. Conclusions: Focal ameloblastoma possibly represents the early stage of ameloblastoma development.

Key words:Ameloblastoma, odontogenic epithelium, dentigerous cyst, dental follicle.

A study on dentigerous cystic changes with radiographically normal impacted mandibular third molars

BACKGROUND

Dentigerous cyst develops in the follicular tissue surrounding the impacted lower third molar. A study was carried out to know the incidence of Association of Dentigerous cyst with radiographically normal impacted lower third molars and to draw the attention of the Oral Surgeons towards the prophylactic removal of impacted third molars.

METHODS

A prospective study was done on 30 patients with impacted lower third molars which were indicated for extraction. The follicle tissue surrounding the impacted tooth was subjected for histopathologic investigations. Only those teeth with a radiographic finding of pericoronal space of less than 2.5 mm were considered. Two Oral Pathologists reviewed the slides for any changes suggestive of cystic pathology.

RESULTS

Pathologic changes suggestive of Dentigerous cyst was found in 7 of the 30 follicular tissue sent for histopathologic testing. It was found to be statistically significant (P < 0.001).

CONCLUSION

This study shows statistically high incidence of Dentigerous cyst association with radiographically normal impacted lower third molar teeth. Hence the Oral and Maxillofacial surgeons should consider histopathologic evaluation and radiographic diagnosis in the management of impacted lower third molars. Prophylactic extractions of normal impacted lower third molars should be considered as a treatment option.

Benign cysts and tumors of the paranasal sinuses

To thoroughly understand the biology of any lesion and render the appropriate management, clear and accurate definitions are paramount. For benign cysts and tumors of the oral maxillofacial region, an accurate depiction of these lesions needs to be elucidated to provide both the treating surgeon and the patient with a clear understanding of the course of treatment and the outcome.

Pericoronal follicles of asymptomatic impacted teeth: a radiographic, histomorphologic, and immunohistochemical study

Objective. To associate radiographic and histopathological features of pericoronal follicles (PFs) of asymptomatic impacted teeth and evaluate cell proliferation and apoptosis in the epithelium. Study Design. Epithelium and mesenchyme of radiographically normal (NPF ≤ 2.5 mm) and hyperplastic (HPF 2.6 to 5 mm) PF (n = 140) were studied histologically. Cell proliferation (PI) and epithelial apoptosis were evaluated by Ki-67 and bcl-2 expression in 14 NPFs and 10 dentigerous cysts (DCs). Results. Radiographically, 127 were NPFs and 13 were HPFs; 87.8% of total PFs exhibited epithelium on the surface. Reduced enamel epithelium was observed in 78 (61.4%) NPFs and 6 (46.2%) HPFs, squamous metaplasia in 17 (13.4%) NPFs and 4 (30.8%) HPFs, and cystic epithelium in 15 (11.8%) NPFs and 3 (23%) HPFs. Mean PI was 1.97 ± 1.25 and 7.97 ± 1.74 in the epithelial component of NPF and DC, respectively; bcl-2 positive expression was observed in 9 (64.3%) NPFs and 7 (70%) DCs. Conclusion. The scant epithelial remnant proliferation could imply low risk for development of odontogenic pathologies in the absence of an additional stimulus.

[Histological analysis of dental follicles after unerupted mandibular third molar extraction]

INTRODUCTION

The extraction of third mandibular tooth germ (M3) is often prophylactic to avoid orthodontic treatment relapse and to prevent infectious or tumoral diseases developing from the dental sac. The purpose of this study was to screen for early histopathological modification of dental follicles (inflammatory, infiltration, or epithelial metaplasia) after extraction of third mandibular tooth germ (M3) on asymptomatic patients. The secondary objective was to study the proliferative activity of the epithelium by dosing the anti Ki-67 antibody.

PATIENTS AND METHOD

Twenty dental follicles extracted from 12 boys and eight girls between 14 and 18 years of age were examined under phototonic microscopy. The proliferative activity of the epithelium was assessed by immuno-histochemistry.

RESULTS

Three dental follicles presented with focal epidermoid metaplasia of the epithelium, without odontogenic tumoral proliferation. In all other cases, the cylindrical epithelial cell structure was normal. A mild chronic inflammatory infiltrate was present in 30% of the cases. Immuno-histochemical analysis revealed labeling of very rare epithelial lining cells, slightly more in cases presenting with metaplasia.

DISCUSSION

The prevalence of early morphological changes of dental sac is low. This histo-morphological study does not support the systematic extraction of asymptomatic mandibular tooth germs (M3).

Malondialdehyde levels in dental follicles of asymptomatic impacted third molars

PURPOSE

Increased levels of reactive oxygen species lead to oxidative stress and tissue damage. Malondialdehyde (MDA) is one of many low-molecular-weight endproducts of lipid peroxidation that increases with oxidative stress. The aim of this study was to determine oxidative stress in dental follicles (DFs) of radiologically asymptomatic impacted third molars (ITMs) using MDA.

MATERIALS AND METHODS

This study involved 40 DFs of 40 patients referred for clinically and radiographically asymptomatic ITMs. Forty healthy gingival tissues in the same patients were obtained during surgical removal of teeth as a control group. DF widths on periapical radiographs narrower than 2.5 mm were included in the study. All tissues samples were analyzed for MDA as an indicator of oxidative stress.

RESULTS

Levels of MDA were significantly higher in DFs from ITMs than those from healthy gingival tissues of the same patients (P < .01).

CONCLUSION

The results suggest that significant oxidative stress may occur in DFs of asymptomatic ITMs. The findings suggest that increased MDA may play an important role in oxidative stress in DFs. In light of these preliminary findings of the present study, further investigations and comprehensive studies are required to determine the role of antioxidants that scavenge free radicals in DFs.

Odontogenic epithelium: immunolabeling of Ki-67, EGFR and survivin in pericoronal follicles, dentigerous cysts and keratocystic odontogenic tumors

The aim of this study was to evaluate the biological profile of odontogenic epithelium by immunolabeling of epidermal growth factor receptor (EGFR), Ki-67 and survivin in keratocystic odontogenic tumors (KOT), dentigerous cysts (DC), and pericoronal follicles (PF). Immunohistochemical analysis was performed in 13 KOTs, 14 DCs and 9 PFs. Immunolabeling was analyzed in the basal and suprabasal layers of KOTs and DCs, and in the islands of odontogenic epithelium and/or reduced enamel epithelium of PFs. KOTs showed the highest proliferation rate among the three groups, mainly in suprabasal layers. EGFR immunolabeling was observed mainly in the cytoplasm in basal and suprabasal layers of KOTs and in the suprabasal layer of DCs. Immunolabeling in both membrane and cytoplasm was greater in PFs. In PFs, membrane-only staining was observed. Survivin immunolabeling showed a greater percentage of positive cells (scoring +++) in the suprabasal layer of KOTs. In DCs, both layers showed similar percentages of cells scoring +++; PFs showed the highest percentage of these cells. In KOTs, epithelial cells showed stimulus-independent neoplastic proliferative characteristics, suggesting the presence of a suprabasal proliferative compartment, maintained by inhibition of apoptosis. In DCs, the basal layer seemed to proliferate in response to stimulus. Although PFs showed low proliferative activity, the expression of EGFR indicates that some cells have a high capacity to respond to stimuli, which could probably explain the origin of odontogenic lesions.

Determination of potential cellular proliferation in the odontogenic epithelia of the dental follicle of the asymptomatic impacted third molars

PURPOSE

The aim of this study is to determine the proliferative potentials of dental follicles (DF) of radiographically asymptomatic impacted third molar teeth by using Ki-67 and mini-chromosome maintenance protein 2 (MCM-2) proliferation markers, and to discuss whether there is any necessity for the removal of all impacted third molars by detecting the potential of the developing cysts and tumors of its DF.

MATERIALS AND METHODS

This study involved 59 DF of 54 patients referred for clinically and radiographically asymptomatic lower impacted third molars. Thirteen healthy gingiva tissues obtained during the impacted third molar operation in 13 patients served as a control group. DF widths on periapical radiographs below 2.5 mm were included in the study. The epithelial and mesenchymal components of DF were examined histologically. All specimens were stained with periodic acid Schiff, Alcian blue, and mucin for the evaluation of mucous cell prosoplasia. Epithelial cell proliferation was determined by using immunohistochemical labeling.

RESULTS

The histologic examinations showed 11.9% mucous cell prosoplasia, 55.9% squamous metaplasia, 15.3% glandular epithelium, and 33.9% inflammation. Ki-67 expression was found to have higher values than MCM-2 expression in controls 6.15 (3.18) and 10.53 (5.77) and in DF 4.46 (1.39) and 5.89 (2.89), respectively. The expression of both proliferation markers in the basal epithelial cells, mucous, and squamous epithelium and inflammatory cells were statistically significant (P < .01).

CONCLUSION

The results of this study indicate that the odontogenic epithelium in DF of asymptomatic impacted third molars might be actively proliferating and may be an indicator for the differentiation potential of DF. It would also seem that the inflammation observed in the mesenchymal components of DF up-regulate the cell turnover of odontogenic epithelium and lead to proliferation. Based on these observations, we support prophylactic removal of impacted third molars.

Extraction versus nonextraction management of third molars

Surgical removal of impacted third molars is the most commonly performed procedure by oral and maxillofacial surgeons. The removal of diseased or symptomatic third molars has not been an issue of controversy. The risk of surgery and associated complications are justified and uniformly accepted by most surgeons when the teeth are associated with chronic or acute pathologic processes, including caries, nonrestorable teeth, fractured roots, resorption, associated pathologic conditions (cysts, tumors), periapical abscesses, odontogenic infections, osteomyelitis, removal before reconstructive or ablative surgery, and radiation therapy.