Indian Journal of Dental ResearchIndian Journal of Dental ResearchIndian Journal of Dental Research
Indian Journal of Dental Research   Login   |  Users online: 1011

Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size         


Table of Contents   
Year : 2020  |  Volume : 31  |  Issue : 1  |  Page : 80-84
Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study

1 Universidade Federal Da Bahia, Bahia, Brazil
2 Universidade Federal do Rio Grande Do Sul, Porto Alegre, Brazil
3 Centro Universitário Franciscano, Santa Maria, Brazil

Click here for correspondence address and email

Date of Submission29-May-2018
Date of Decision19-Jun-2018
Date of Acceptance16-Jul-2018
Date of Web Publication02-Apr-2020


Aim: This study aimed to analyze the prevalence of diseases related to pericoronal follicles, and assess the rate of concordance between clinical and histopathological diagnoses. Methods: Histologically, we analyzed 1,298 tissue samples surrounding the crowns of teeth that were diagnosed clinically as pericoronal follicles. In addition, we determined associations among histopathological diagnosis, patients' age and sex, tissue site, presence of nests of odontogenic epithelium, presence of reduced enamel epithelium, and presence of diffuse inflammation. Results: Odontogenic pathologies were present in 35% of the samples, and rate of concordance between clinical and histopathological diagnoses was 0.54. Probability of developing odontogenic pathologies was high in the mandibular molars (odds ratio: 2.13) and in the tissues with odontogenic epithelial remnants (odds ratio: 1.2), reduced enamel epithelium (odds ratio: 1.3), and diffuse inflammation. (odds ratio: 10.5). Conclusions: The findings of this study highlight the clinical relevance of histopathological examination of the pericoronal tissue in unerupted and partially erupted teeth for early diagnosis of pathologies because this study demonstrated the odontogenic cysts and inflammatory lesions in tissues clinically diagnosed as pericoronal follicles.

Keywords: Dentigerous cyst, diagnosis, odontogenic cysts, oral and maxillofacial pathology, oral, pericoronitis

How to cite this article:
da Silva VP, Meyer Gd, Daroit NB, Maraschin BJ, de Oliveira MG, Visioli F, Rados PV. Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study. Indian J Dent Res 2020;31:80-4

How to cite this URL:
da Silva VP, Meyer Gd, Daroit NB, Maraschin BJ, de Oliveira MG, Visioli F, Rados PV. Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study. Indian J Dent Res [serial online] 2020 [cited 2021 May 11];31:80-4. Available from:

   Introduction Top

Unerupted teeth are commonly affected by odontogenic lesions.[1],[2],[3],[4] Pericoronal follicles are tissue that surround the crown of unerupted teeth, which consist of connective tissue containing nests of odontogenic epithelium.[5] These structures are reported to have the potential to proliferate and develop into odontogenic cysts and tumors.[1],[2],[4],[6]

The prevalence rate of the development of odontogenic lesions associated with impacted teeth shows discrepancy among reports in the literature; however, the overall conclusion is that their development is uncommon.[7],[8],[9],[10],[11] Most studies have analyzed radiographic imaging data alone, including some with long-term follow-up.[7],[10],[11],[12],[13] It is likely that many odontogenic and inflammatory lesions were not confirmed, due to absence of associated symptoms and radiographic evidence.[2]

In routine clinical practice, tissues are further examined only under radiographic image finding of large radiolucent areas.[14],[15],[16],[17] The aim of this study was to microscopically evaluate the tissues surrounding the crowns of unerupted teeth that were clinically diagnosed as pericoronal follicles.

   Methods Top

Our institutions' Research Ethics Committee approved the study design. The study was conducted in accordance with the Declaration of Helsinki. All samples that were clinically diagnosed as pericoronal follicles, over an eight-year period, were selected from oral pathology laboratory archives. Patients' age, sex, lesion site, presence of odontogenic epithelial remnants, reduced enamel epithelium, and diffuse inflammation were recorded.

Histopathological diagnosis was established according to the following criteria: Presence of pericoronal follicles composed of fibrous connective tissue surrounding the crown of impacted tooth, possibly with myxoid changes, odontogenic epithelial remnants, and/or reduced enamel epithelium exhibiting a nest or string formation [Figure 1]a;[18] presence of dentigerous cysts showing three or more layers of non-keratinized stratified squamous epithelium surrounding the crown of unerupted tooth, over a capsule of connective tissue of variable density, possibly containing odontogenic epithelial remnants and reduced enamel [Figure 1]b;[3] presence of paradental cysts showing either isolated cystic stratified squamous epithelium surrounding the crown of partially erupted tooth, or in continuity with the sulcular and mucosal epithelium [Figure 1]c;[18] and finally, tissue samples with pericoronitis showing presence of hyperplastic sulcular epithelium with exocytosis and dense, homogenous inflammatory cell infiltration in the entire area [Figure 1]d.[19] In addition, analysis of each slide indicated the presence of reduced enamel epithelium, nests of odontogenic epithelium, and diffuse inflammation.
Figure 1: Photomicrographs of representative cases of different histopathological diagnosis. (a) Pericoronal follicle showing reduced enamel epithelia and odontogenic epithelial remnants. (b) Dentigerous cyst showing hyperplastic non-keratinized stratified epithelium lining. (c) Paradental cyst showing cystic stratified squamous epithelium with cord-like anastomoses of intense inflammatory cells continuous with parakeratinized stratified mucosal epithelium. (d) Pericoronitis showing mucosal tissue lined by parakeratinized stratified squamous epithelium and chronic inflammatory infiltrate (H/E)

Click here to view

From a total of 7,228 specimens registered in the pathology laboratory, 1,326 samples (18.34%) were clinically diagnosed as pericoronal follicles. We excluded 28 samples either because of nonavailability of slides/blocks or because of insufficient material for further analysis. Diagnoses other than those described above were categorized as other (fragments of mucosa, giant cell lesions, blood clots, chronic non-specific inflammation). We classified the lesion site into following five categories: Mx-ICP (maxillary incisors, canines, and premolars); Mx-M (maxillary molars); Md-ICP (mandibular incisors, canines, and premolars); Md-M (mandibular molars); and SUPER (supernumerary teeth). Patients' age was classified into following four categories: 0-10, 11-20, 21-30, and 31-59 years.

Slides were assessed by two previously calibrated examiners (VPS, MGO), intra-examiner kappa values were calculated, and results >0.7 were considered as acceptable. Rate of agreement between clinical and histopathological diagnoses was calculated using prevalence-adjusted and bias-adjusted kappa (PABAK-OS) test. Other analyses such as Chi-square test, Yates' correction for continuity, Fisher's exact test, and logistic regression were performed. Results were analyzed using Statistical Package for the Social Sciences (SPSS) version 19 (Armonk, NY: IBM Corp.). Statistical significance was set at P < 0.5%.

   Results Top

The final sample comprised of 1,298 specimens, of which, 35% had final diagnosis based on microscopy finding that differed from initial clinical diagnosis. Rate of concordance between clinical and histopathological diagnoses was 0.54 (PABAK-OS). Distribution of the five histopathological diagnostic categories is shown in [Table 1].
Table 1: Correlation of histopathological diagnostic category with patients' sex and lesion site

Click here to view

Statistically significant association was found between patients' sex and diagnosis of paradental cysts, with female predilection (54% of female patients vs 46% of male patients). Pericoronitis was diagnosed in 52% of male patients and 48% of female patients. Pericoronal follicles and dentigerous cysts were more prevalent among women, with diagnosis in 71% of female patients and 29% of male patients [Table 1].

With regard to lesion site, 72% of patients had lesions in the mandibular third molars; whereas, at other sites, pericoronal follicle was the most frequent diagnosis. There were no cases of pericoronitis or paradental cysts in the Mx-ICP, Md-ICP, and SUPER groups [Table 1]. Analysis of age distribution showed that pericoronal follicles were more prevalent in the 11-20 years' age group, whereas, paradental cysts and pericoronitis were more common in the 21-30 years'age group [Figure 2]. Significant associations were observed between pathological diagnoses and presence of reduced enamel epithelium, odontogenic epithelial remnants, and diffuse inflammation [Figure 3].
Figure 2: Distribution of cases based on histopathological diagnosis and age

Click here to view
Figure 3: Correlation between diagnoses and specific histopathological findings. PF, pericoronal follicle; DC, dentigerous cyst; PC, paradental cyst; PERI, pericoronitis; REE, reduced enamel epithelium; OER, odontogenic epithelial remnants

Click here to view

Odds ratio analysis revealed that likelihood of developing pathologies was 1.13-fold higher when the tissues originated from the mandibular molar (odds ratio: 2.13); in addition, the likelihood of developing pathologies increased in the presence of reduced enamel epithelium, odontogenic epithelial remnants, and diffuse inflammation (odds ratio: 1.3, 1.2, and 10.5, respectively).

   Discussion Top

In clinical practice, histopathological examination of pericoronal follicles is usually neglected[20] in cases with normal radiographic findings and absence of symptoms.[14],[20],[21] Sample size in our study (approximately 1000) was similar to those in another study regarding odontogenic lesions related to pericoronal follicles.[2] In this study, 35% of tissue samples collected from around the crowns of unerupted teeth showed histopathological abnormalities and were diagnosed as dentigerous cysts, paradental cysts, or pericoronitis, despite absence of radiographic abnormalities, indicative of need for histopathological examination in confirmed diagnosis of clinically unsuspected lesions.

Based on previous reports, odontogenic epithelial remnants and reduced enamel epithelium that are present in pericoronal follicles have potential to develop into odontogenic cysts or tumors under exposure to certain stimuli.[4] This was described in two cases of pericoronal follicles with histopathological diagnosis of ameloblastoma that did not show clinical or radiographic signs of disease prior to microscopic examination.[22]

In this study, dentigerous cyst was the most frequent histopathological diagnosis. Reports lack consensus regarding criteria for differentiation of pericoronal follicles and dentigerous cysts. Currently, diagnosis of dentigerous cyst requires combined presence of clinical, surgical, radiographic, and histological characteristics compatible with the condition; in the absence of any of these features, diagnosis of pericoronal follicle should be established.[5],[14],[16],[23] Alternatively, presence of stratified squamous epithelium on microscopic examination is a characteristic sign of cell activation and proliferation. This morphologic finding is sufficient for diagnosis of dentigerous cyst.[3],[20],[21] These events could be interpreted as the initial stage of cystic development, which does not produce radiographic evidence of bone resorption. da Silva Baumgart et al.[4] showed that the proliferative potential of reduced enamel epithelium may be similar to that of normal mucosa.

Paradental cysts and pericoronitis are more commonly associated with partially erupted molars. They result from accumulation of bacteria in periodontal tissues surrounding the crown of the tooth, causing inflammatory reactions and thus, triggering disease progression.[19] We detected diffuse inflammation in 70.5% of samples diagnosed with paradental cysts, and in 100% of those diagnosed with pericoronitis. In addition, we observed that in the presence of inflammation, tissues surrounding the crowns of unerupted teeth had 10.5% higher probability of developing pathologies, compared with those without signs of inflammation (odds ratio: 10.5). Thus, inflammatory process is a potential influencing factor in pathogenesis of the lesions.

In our study, pathologies were more frequently found in tissue samples from patients aged 11–30 years, which is in accordance with previously reported findings.[24],[25],[26] Moreover, with increasing age, dentigerous cysts showed higher frequency of occurrence than that of pericoronal follicles. This corroborates the hypothesis of positive correlation between duration in situ of the epithelial remnants and possibility of odontogenic lesions' development.[2],[3],[20],[26]

Further evidence included finding of increase in number of inflammatory odontogenic lesions, such as pericoronitis and paradental cysts, with increase in patients' age [Figure 2], possibly due to presence of semi-erupted teeth and consequently, biofilm accumulation. In our study, paradental cyst was more prevalent in female patients. This result is in accordance with that of de Souza et al.[27] and in contrast to that of others studies,[28],[29] possibly because the study population in the former was Brazilian, as was our study.

Access to results of radiographic examination was not possible in our study; instead, this information was provided by the surgeon. In future analysis, such data would be important to correlate with histopathological aspects; moreover, use of molecular markers as immunohistochemistry, can be effective to elucidate etiopathogenesis to improve understanding of these lesions.

   Conclusions Top

In summary, there is evident gap in knowledge of management of soft tissue surrounding the crowns of unerupted teeth, under absence of characteristic radiological findings, including proliferative potential and treatment approach. Finding of high percentage rate of lesions observed in our sample suggests that tissues surrounding the crowns of unerupted teeth are highly likely to develop into pathological forms including odontogenic lesions. Based on our findings, diseases of odontogenic origin are under-diagnosed; pathologies of odontogenic origin may be diagnosed early and managed adequately by combined clinical, radiographic, and microscopic information.


School of Dentistry of Universidade Federal do Rio Grande do Sul and the financial support of the Coordination and Improvement of Higher Level or Education Personnel (CAPES). The authors wish to specially acknowledge Dr. Manoel Sant'Ana Filho for her contribution in histopathological diagnostics.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Adelsperger J, Campbell JH, Coates DB, Summerlin DJ, Tomich CE. Early soft tissue pathosis associated with impacted third molars without pericoronal radiolucency. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89:402-6.  Back to cited text no. 1
Curran AE, Damm DD, Drummond JF. Pathologically significant pericoronal lesions in adults: Histopathologic evaluation. J Oral Maxillofac Surg 2002;60:613-7.  Back to cited text no. 2
Glosser JW, Campbell JH. Pathologic change in soft tissues associated with radiographically 'normal' third molar impactions. Br J Oral Maxillofac Surg 1999;37:259-60.  Back to cited text no. 3
da Silva Baumgart C, da Silva Lauxen I, Filho MS, de Quadros OF. Epidermal growth factor receptor distribution in pericoronal follicles: Relationship with the origin of odontogenic cysts and tumors. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:240-5.  Back to cited text no. 4
Daley TD, Wysocki GP. The small dentigerous cyst. A diagnostic dilemma. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:77-81.  Back to cited text no. 5
Cabbar F, Güler N, Comunoǧlu N, Sençift K, Cöloǧlu S. Determination of potential cellular proliferation in the odontogenic epithelia of the dental follicle of the asymptomatic impacted third molars. J Oral Maxillofac Surg 2008;66:2004-11.  Back to cited text no. 6
van der Linden W, Cleaton-Jones P, Lownie M. Diseases and lesions associated with third molars. Review of 1001 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:142-5.  Back to cited text no. 7
Anderson M. Removal of asymptomatic third molars: Indications, contraindications, risks and benefits. J Indiana Dent Assoc 1998;77:41-6.  Back to cited text no. 8
Girod SC, Gerlach KL, Krueger G. Cysts associated with long-standing impacted third molars. Int J Oral Maxillofac Surg 1993;22:110-2.  Back to cited text no. 9
Kahl B, Gerlach KL, Hilgers RD. A long-term, follow-up, radiographic evaluation of asymptomatic impacted third molars in orthodontically treated patients. Int J Oral Maxillofac Surg 1994;23:279-85.  Back to cited text no. 10
Stanley HR, Alattar M, Collett WK, Stringfellow HR Jr. Spiegel EH. Pathological sequelae of “neglected” impacted third molars. J Oral Pathol 1988;17:113-7.  Back to cited text no. 11
Eliasson S, Heimdahl A, Nordenram A. Pathological changes related to long-term impaction of third molars. A radiographic study. Int J Oral Maxillofac Surg 1989;18:210-2.  Back to cited text no. 12
Ahlqwist M, Gröndahl HG. Prevalence of impacted teeth and associated pathology in middle-aged and older Swedish women. Community Dent Oral Epidemiol 1991;19:116-9.  Back to cited text no. 13
Damante JH, Fleury RN. A contribution to the diagnosis of the small dentigerous cyst or the paradental cyst. Pesqui Odontol Bras 2001;15:238-46.  Back to cited text no. 14
Simşek-Kaya G, Özbek E, Kalkan Y, Yapici G, Dayi E, Demirci T, et al. Soft tissue pathosis associated with asymptomatic impacted lower third molars. Med Oral Patol Oral Cir Bucal 2011;16:e929-36.  Back to cited text no. 15
Stathopoulos P, Mezitis M, Kappatos C, Titsinides S, Stylogianni E. Cysts and tumors associated with impacted third molars: Is prophylactic removal justified? J Oral Maxillofac Surg 2011;69:405-8.  Back to cited text no. 16
Villalba L, Stolbizer F, Blasco F, Mauriño NR, Piloni MJ, Keszler A, et al. Pericoronal follicles of asymptomatic impacted teeth: A radiographic, histomorphologic, and immunohistochemical study. Int J Dent 2012;2012:935310.  Back to cited text no. 17
Kim J, Ellis GL. Dental follicular tissue: Misinterpretation as odontogenic tumors. J Oral Maxillofac Surg 1993;51:762-7.  Back to cited text no. 18
Philipsen HP, Reichart PA, Ogawa I, Suei Y, Takata T. The inflammatory paradental cyst: A critical review of 342 cases from a literature survey, including 17 new cases from the author's files. J Oral Pathol Med 2004;33:147-55.  Back to cited text no. 19
Yildirim G, Ataoǧlu H, Mihmanli A, Kiziloǧlu D, Avunduk MC. Pathologic changes in soft tissues associated with asymptomatic impacted third molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:14-8.  Back to cited text no. 20
Tegginamani AS, Prasad R. Histopathologic evaluation of follicular tissues associated with impacted lower third molars. J Oral Maxillofac Pathol 2013;17:41-4.  Back to cited text no. 21
[PUBMED]  [Full text]  
da Silva VP, Nör F, Gomes e Nóbrega T, Oliveira MG, Rados PV, Sant'Ana Filho M, et al. The importance of histopathologic analysis of pericoronal follicles for the early identification of ameloblastomas. J Craniofac Surg 2015;26:e231-2.  Back to cited text no. 22
Slater LJ. Comments on “Pathologic changes in the soft tissues associated with asymptomatic impacted third molars”. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:5.  Back to cited text no. 23
Carvalho Mde V, Iglesias DP, do Nascimento GJ, Sobral AP. Epidemiological study of 534 biopsies of oral mucosal lesions in elderly Brazilian patients. Gerodontology 2011;28:111-5.  Back to cited text no. 24
Prockt AP, Schebela CR, Maito FD, Sant'Ana-Filho M, Rados PV. Odontogenic cysts: Analysis of 680 cases in Brazil. Head Neck Pathol 2008;2:150-6.  Back to cited text no. 25
Sharifian MJ, Khalili M. Odontogenic cysts: A retrospective study of 1227 cases in an Iranian population from 1987 to 2007. J Oral Sci 2011;53:361-7.  Back to cited text no. 26
de Souza LB, Gordón-Núñez MA, Nonaka CF, de Medeiros MC, Torres TF, Emiliano GB, et al. Odontogenic cysts: Demographic profile in a Brazilian population over a 38-year period. Med Oral Patol Oral Cir Bucal 2010;15:e583-90.  Back to cited text no. 27
Mosqueda-Taylor A, Irigoyen-Camacho ME, Diaz-Franco MA, Torres-Tejero MA. Odontogenic cysts. Analysis of 856 cases. Med Oral 2002;7:89-96.  Back to cited text no. 28
Kambalimath DH, Kambalimath HV, Agrawal SM, Singh M, Jain N, Anurag B, et al. Prevalence and distribution of odontogenic cyst in Indian population: A 10 year retrospective study. J Maxillofac Oral Surg 2014;13:10-5.  Back to cited text no. 29

Correspondence Address:
Pantelis Varvaki Rados
Faculdade de Odontologia, Universidade Federal Do Rio Grande Do Sul., R. Ramiro Barcelos, 2492 Porto Alegre, RS
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijdr.IJDR_459_18

Rights and Permissions


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  

    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded26    
    Comments [Add]    

Recommend this journal