Cysts and Pseudocysts of the Oral Cavity: Revision of the Literature and a New Proposed Classification

CD34 and Ki-67 Immunoexpression in Periapical Granulomas: Implications for Angiogenesis and Cellular Proliferation

BACKGROUND/OBJECTIVES

The main mechanism of the formation of granulation tissue is the progression of an infection from the tooth to the periapical bone. At this level, the immune system tries to localize and annihilate the microorganism's injury. Ki-67 is a protein directly associated with the cell proliferation rate, while CD34 is a biomarker involved in angiogenesis, and studies suggest that they both have a positive correlation with the intensity of the local inflammatory infiltrate. This study will determine the immunoexpression of CD34 and Ki-67 in periapical granulomas and assess their impact on the growth and development of this tissue, as well as consider their roles in the proliferative process and aggressiveness of evolution.

METHODS

In the present study, 35 periapical granulomas obtained after a tooth extraction were included. The specimens were analyzed via histopathology and immunohistochemistry.

RESULTS

A positive reaction for the Ki-67 antibody was observed in 32 (86.5%) of the 35 periapical granuloma cases included in our study. We identified the overexpression of Ki-67 and CD34 and further calculated the Ki-67 index to evaluate and correlate the proliferation potential and angiogenesis with regard to the presence of an inflammatory infiltrate.

CONCLUSIONS

These findings suggest that the persistence of an inflammatory environment directly influences Ki-67 and CD34 expression, sustaining the proliferative capacity of cells and abnormal angiogenesis. This study is the first to evaluate the presence of the CD34+ and Ki-67+ proliferating vessels in periapical granulomas.

Molecular pathogenicity of 1-nonadecene and L-lactic acid, unique metabolites in radicular cysts and periapical granulomas

Recently, 1-nonadecene and L-lactic acid were identified as unique metabolites in radicular cysts and periapical granuloma, respectively. However, the biological roles of these metabolites were unknown. Therefore, we aimed to investigate the inflammatory and mesenchymal-epithelial transition (MET) effects of 1-nonadecene, and the inflammatory and collagen precipitation effects of L-lactic acid on both periodontal ligament fibroblasts (PdLFs) and peripheral blood mononuclear cells (PBMCs). PdLFs and PBMCs were treated with 1-nonadecene and L-lactic acid. Cytokines' expression was measured using quantitative real-time polymerase chain reaction (qRT-PCR). E-cadherin, N-cadherin, and macrophage polarization markers were measured using flow cytometry. The collagen, matrix metalloproteinase (MMP)-1, and released cytokines were measured using collagen assay, western blot, and Luminex assay, respectively. In PdLFs, 1-nonadecene enhances inflammation through the upregulation of some inflammatory cytokines including IL-1β, IL-6, IL-12A, monocyte chemoattractant protein (MCP)-1, and platelet-derived growth factor (PDGF) α. 1-Nonadecene also induced MET through the upregulation of E-cadherin and the downregulation of N-cadherin in PdLFs. 1-Nonadecene polarized macrophages to a pro-inflammatory phenotype and suppressed their cytokines' release. L-lactic acid exerted a differential impact on the inflammation and proliferation markers. Intriguingly, L-lactic acid induced fibrosis-like effects by enhancing collagen synthesis, while inhibiting MMP-1 release in PdLFs. These results provide a deeper understanding of 1-nonadecene and L-lactic acid's roles in modulating the microenvironment of the periapical area. Consequently, further clinical investigation can be employed for target therapy.

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.

Clinical, Radiographic and Histologic Evaluation of 40 Cystic Oral Lesions in 37 Cats

Feline cystic oral lesions are uncommon and include odontogenic cysts and cystic odontogenic tumors. Accurate diagnosis requires close collaboration between the clinician's clinical and radiographic findings and the pathologist's histologic interpretations. The odontogenic cysts identified in this series include a periapical cyst, dentigerous cysts and a type of unclassified collateral cyst that appears to be a previously undefined, distinct entity in cats (UCC). Many of the cysts (52%) were unable to be classified due to insufficient diagnostic information, which often related to the associated tooth being unavailable for evaluation. Cystic odontogenic tumors included ameloblastomas, amyloid producing ameloblastomas (APA), and feline inductive odontogenic tumors (FIOT). The purpose of this case series was to assess correlations between clinical and radiographic findings, histopathologic interpretation and signalment to identify common characteristics and provide recommendations for clinicians and pathologists to optimize diagnostic efficiency and accuracy for cystic oral lesions in cats.

Odontogenic Chronic Rhinosinusitis: Structured Histopathology Evidence in Different Patho-Physiological Mechanisms

An increased odontogenic chronic rhinosinusitis (oCRS) occurrence rate has quite recently been reported, likely due to an intensification of conservative dental surgery and implantology. The main aim of the study was to report for the first time the structured histopathological characteristics of the surgical specimens of oCRS. Possible associations between histopathological features and oCRS patho-physiological mechanisms were also evaluated. Structured histopathology features were investigated in the sinonasal mucosa tissue of 42 consecutive oCRS patients.Mean tissue eosinophil counts were significantly different between oCRS with radicular cysts, dental implants, or other dental diseases (p =0.0118): mean tissue eosinophil count was higher in oCRS with dental implants. Sub-epithelial edema score and squamous metaplasia presence were significantly different when comparing the above-mentioned sub-cohorts of oCRS (p =0.0099 and p =0.0258). In particular, squamous metaplasia was more present in oCRS cases with radicular cysts than in those with a dental implant (p =0.0423). Fibrosis presence was significantly different comparing the three sub-cohorts of oCRS (p =0.0408), too. This preliminary evidence supports the hypothesis that: (i) structural histopathology can become a useful tool for clinic-pathological practice in diagnostic, therapeutic, and prognostic terms in CRS; (ii) that oCRS, as CRS in general, is a histo-pathologically heterogeneous disease; (iii) oCRS resulting from dental implants disorders can frequently be characterized as a CRS with a rich tissue eosinophilic component.

Efficacy of bone grafts in jaw cystic lesions: A systematic review

BACKGROUND

Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects. Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture, loss of teeth, and infection. However, whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.

AIM

To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.

METHODS

A literature search was performed in Medline, Cochrane Library and Embase to identify related articles published in English in the last ten years. The following key words and MeSH terms were used: “jaw cyst”, “cystic lesion”, “odontogenic cyst”, “periapical cyst”, “dentigerous cyst”, “follicular cyst”, “keratocyst”, “treatment”, “surgery”, “bone graft”, “enucleation”, “cystectomy”, and “bone regeneration”. Case reports, clinical trials, clinical studies, observational studies and randomized controlled trials were included. Study quality was evaluated.

RESULTS

Ten studies (n = 10) met the inclusion criteria. Five studies reported spontaneous bone healing after enucleation, three studies investigated the efficacy of various bone grafts, and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting. Over 90% of bone regeneration occurred within 6 mo after bone grafting. The bone regeneration rate after cystectomy showed great variation, ranging from 50% to 100% after 6 mo, but reaching over 90% after 12 mo.

CONCLUSION

While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear, bone grafts accelerate the process of healing and significantly increase bone quality.

Efficacy of bone grafts in jaw cystic lesions: A systematic review

BACKGROUND

Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects. Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture, loss of teeth, and infection. However, whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.

AIM

To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.

METHODS

A literature search was performed in Medline, Cochrane Library and Embase to identify related articles published in English in the last ten years. The following key words and MeSH terms were used: “jaw cyst”, “cystic lesion”, “odontogenic cyst”, “periapical cyst”, “dentigerous cyst”, “follicular cyst”, “keratocyst”, “treatment”, “surgery”, “bone graft”, “enucleation”, “cystectomy”, and “bone regeneration”. Case reports, clinical trials, clinical studies, observational studies and randomized controlled trials were included. Study quality was evaluated.

RESULTS

Ten studies (n = 10) met the inclusion criteria. Five studies reported spontaneous bone healing after enucleation, three studies investigated the efficacy of various bone grafts, and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting. Over 90% of bone regeneration occurred within 6 mo after bone grafting. The bone regeneration rate after cystectomy showed great variation, ranging from 50% to 100% after 6 mo, but reaching over 90% after 12 mo.

CONCLUSION

While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear, bone grafts accelerate the process of healing and significantly increase bone quality.

Quiste dentígero. Revisión de la literatura y reporte de caso

Introducción: el quiste dentígero, también conocido como quiste folicular, es la segunda forma más habitual de los quistes de la región maxilar después del quiste radicular. Tiene una incidencia del 20% con respecto a todos los quistes odontogénicos y se encuentra más en el género masculino entre los 20-40 años. El manejo conservador en lesiones quísticas de gran tamaño es indispensable para evitar defectos óseos o daño a estructuras vecinas. Sin embargo, en lesiones de menor tamaño, la enucleación continúa siendo el tratamiento de elección. Objetivo: presentar un caso clínico de un quiste dentígero y hacer una revisión de la literatura actualizada. Caso clínico: paciente masculino de 23 años que presentó aumento de volumen en zona geniana derecha y, además, en su ortopantomografía se observó una lesión en el sector de los incisivos superiores. Se realizó enucleación de la lesión, cuyo diagnóstico histológico previo fue quiste dentígero y posteriormente se obtiene una correcta regeneración ósea tras un año de seguimiento Conclusión: el manejo del quiste dentígero es variado: puede ir desde la enucleación quirúrgica hasta la descompresión y marsupialización del mismo. No obstante, todos los tratamientos actuales se basan en contrarrestar los factores de expansión quística que permiten a esta lesión alcanzar grandes tamaños intraóseos y poder causar desde rizolisis de dientes adyacentes hasta una asimetría facial como sucedió en este caso clínico.  

Comparative Metabolomics Reveals the Microenvironment of Common T-Helper Cells and Differential Immune Cells Linked to Unique Periapical Lesions

Periapical abscesses, radicular cysts, and periapical granulomas are the most frequently identified pathological lesions in the alveolar bone. While little is known about the initiation and progression of these conditions, the metabolic environment and the related immunological behaviors were examined for the first time to model the development of each pathological condition. Metabolites were extracted from each lesion and profiled using gas chromatography-mass spectrometry in comparison with healthy pulp tissue. The metabolites were clustered and linked to their related immune cell fractions. Clusters I and J in the periapical abscess upregulated the expression of MMP-9, IL-8, CYP4F3, and VEGF, while clusters L and M were related to lipophagy and apoptosis in radicular cyst, and cluster P in periapical granuloma, which contains L-(+)-lactic acid and ethylene glycol, was related to granuloma formation. Oleic acid, 17-octadecynoic acid, 1-nonadecene, and L-(+)-lactic acid were significantly the highest unique metabolites in healthy pulp tissue, periapical abscess, radicular cyst, and periapical granuloma, respectively. The correlated enriched metabolic pathways were identified, and the related active genes were predicted. Glutamatergic synapse (16–20),-hydroxyeicosatetraenoic acids, lipophagy, and retinoid X receptor coupled with vitamin D receptor were the most significantly enriched pathways in healthy control, abscess, cyst, and granuloma, respectively. Compared with the healthy control, significant upregulation in the gene expression of CYP4F3, VEGF, IL-8, TLR2 (P < 0.0001), and MMP-9 (P < 0.001) was found in the abscesses. While IL-12A was significantly upregulated in cysts (P < 0.01), IL-17A represents the highest significantly upregulated gene in granulomas (P < 0.0001). From the predicted active genes, CIBERSORT suggested the presence of natural killer cells, dendritic cells, pro-inflammatory M1 macrophages, and anti-inflammatory M2 macrophages in different proportions. In addition, the single nucleotide polymorphisms related to IL-10, IL-12A, and IL-17D genes were shown to be associated with periapical lesions and other oral lesions. Collectively, the unique metabolism and related immune response shape up an environment that initiates and maintains the existence and progression of these oral lesions, suggesting an important role in diagnosis and effective targeted therapy.

An atypical presentation of a bilateral nasolabial cyst: a case report

The nasolabial cyst is a rare, non-odontogenic, soft tissue cyst that develops submucosally in the anterior nasal floor. This cyst accounts for 0.7% of all non-odontogenic cysts. Bilateral nasolabial cyst represents only 10% of the cases. This cyst originates from the remnants of embryonic nasolacrimal duct tissue. Generally, patients present with swelling and facial deformity and rarely local pain. The definite diagnosis should be based on clinical, radiological and above all histopathologic findings. The treatment is enucleation of the cystic tissue. Following is a case report of a bilateral nasolabial cyst in a 40-year-old woman who presented with a chronic nasal obstruction.

Computed tomographic imaging and surgical treatment of an acquired dentigerous cyst in a Slovakian Chuvach – a case report

Dentigerous cysts occur infrequently in dogs and they should be a primary consideration in young dogs presented with oral swelling in the edentulous area. They are even less common in cats compared to dogs. Classification of lesions in animals is not very different from those described in humans. Dentigerous cysts are most frequently seen affecting the mandibular first premolar area with unerupted mandibular first premolar teeth. This report describes the clinical case of a four-year-old female Slovakian Chuvach that suffered from long-term difficulties associated with epistaxis and swelling of the facial area. Computed tomography revealed a cyst-like structure associated with an intra-nasal canine, prompting the suspected diagnosis of an odontogenic cyst. Histopathological examination of tissues obtained during the subsequent surgical procedure confirmed the diagnosis of a dentigerous cyst.

Calcified shell in the maxillary antrum: An interesting imaging characteristic of an antral cyst

The proximity of the maxillary antrum to the maxillary alveolus and teeth leads to many antral lesions being diagnosed by an oral physician. Antral lesions may be intrinsic pathologies arising from the sinus mucosa itself or as a result of extrinsic odontogenic or non-odontogenic lesions arising from the maxillary alveolus or teeth. We present an interesting case of a 41-year-old lady with a maxillary swelling which clinically appeared as a maxillary cyst, radiologically as a calcified shell in the antrum and eventually the histology showed it was a maxillary antral cyst.