Odontogenic cysts: an update

The clinical outcomes of vital intact teeth close to large cystic lesions of endodontic origin: A prospective clinical study

AIM

To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin.

METHODOLOGY

This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty-two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post-surgery. Student's t-test (p < .05) was used to compare the EPT values at baseline and T4. anova (p < .05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p < .05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response.

RESULTS

At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p > .05), but significant differences were observed for EPT values between T1 and T4 (p < .05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points.

CONCLUSIONS

These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post-surgery follow-up with TPT and EPT is recommended to assess pulp status.

Immunohistochemical Comparison of Ki-67 and MCM-3 in Odontogenic Cysts: An Observational Study

Odontogenic cysts are a diverse group of pathologic entities with different proliferation potential, leading to variations in their biological behavior. One of the most cited proliferation markers used in diagnostic histopathology is Ki-67. Another group of proteins recently investigated is minichromosome maintenance (MCM-3) and its expression has been evaluated in several odontogenic lesions but the results were controversial. Thus, the present study endeavored to compare the expression of MCM-3 and Ki-67 in odontogenic cysts. Furthermore, a pioneer attempt was made to evaluate the sensitivity of these markers to inflammation. A total of 101 cases (37 dentigerous cysts, 37 odontogenic keratocysts, and 27 radicular cysts) were included. Immunohistochemical expression of Ki-67 and MCM-3 were investigated using a labeling index (LI). In addition, they were scored for inflammation, followed by correlation with both markers. The data obtained were subjected to statistical analysis ( P <0.05). Overall, a higher LI of MCM-3 than Ki-67 was obtained in all study groups along with a positive correlation of Ki-67 LI with inflammation. Thus, MCM-3 proteins proved to be a more accurate means to determine the proliferation potential and were not sensitive to external stimuli like inflammation than conventional markers, such as Ki-67.

A review of oral pathology in orthodontics. Part 2: Pathology of the jaw bones

For many patients, their first full jaw imagining will be requested and reported by an orthodontist. This may lead to the discovery of unexpected pathology in the jaws. In this review article, we discuss the clinical and radiological appearance as well as the pathologic features and treatment of the more common entities of the jaws. In addition, we will discuss the less common lesions which carry important consequences for the patient. Through the identification of these lesions, appropriate referral and management can be pursued.

Expression pattern of hypoxia-related genes in odontogenic cysts

OBJECTIVE

The aim of the present study was to reveal the effects of hypoxia-associated signaling in odontogenic cysts.

DESIGN

The expression levels of genes involved in the hypoxia-associated signaling pathway were determined by quantitative Polymerase Chain Reaction (PCR) method.

RESULTS

As a result, it was found that phosphatase and tensin homolog (PTEN) expression was low (p = 0.037), and the expression levels of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (p = 0.0127), hypoxia inducible factor 1 alpha (HIF1A) (p < 0.001), and HIF1A antisense RNA 1 (HIF1A-AS1) (p = 0.0218) were higher in cyst tissue compared to normal tissue. HIF1A gene expression was found to be significantly altered according to the pathologic subtypes of odontogenic keratocyst, dentigerous cyst, and radicular cyst.

CONCLUSIONS

Odontogenic cysts were found to have higher expression of HIF1A and HIF1A-AS1, which may be related to the increased hypoxia in these lesions. In addition, PI3K/Akt signaling may be stimulated by increased PIK3CA and decreased PTEN expression, which promote cell survival and support the mechanism of cyst formation.

Differentiated Immunohistochemical Expression of Osteoclastogenic Markers in Radicular Cyst, Odontogenic Keratocyst, and Ameloblastoma

The aim of this study was to investigate the osteoclastogenesis process by means of immunohistochemical markers for receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), interleukin-6 (IL-6), and cathepsin K (CTSK) antigens in osteolytic lesions of maxillary bones. The sample consisted of 23 radicular cysts (RC), 25 odontogenic keratocysts (OKC), and 25 ameloblastomas (AM). RANKL was statistically higher in RC (49.6±15.2/53.7±18) and OKC (48.6±15.1/51.4±16.8) when compared with AM (37.2±12.5/36.4±13) in the epithelium and connective tissue. OPG was lower in OKC (34.8±18.5) only in connective tissue when compared with RC (44.5±11.2). The expression of RANKL was statistically higher than OPG in RC (epithelium and connective tissue) and OKC (connective tissue). For IL-6, a statistical difference was observed only in the connective tissue between groups, with higher expression in RC (48.2±15) and lower in OKC (22±11.9). The expression of IL-6 was correlated with the intensity of the inflammatory infiltrate. CTSK was statistically higher in AM (34±19) and OKC (29±13.8) compared with RC (19±10.5). According to the results of the present research the bone resorption in cysts and odontogenic tumors occurs through different mechanisms. The ostoclastogenic process in lesions with aggressive clinical behavior, as AM and OKC, seems to be associated with the expression of CTSK. In contrast, lesions with inflammatory etiology, as RC, the expression of IL-6 seems to have an important role in the bone resorption process. The highest expression of RANKL under the expression of OPG also seems to contribute to the growth mechanism of RC and OKC.

Diagnóstico de quiste dentígero en sacos foliculares de terceros molares incluídos

Objetivo: establecer el tipo de patología más frecuente asociada a terceros molares incluidos, extraídos en las clínicas de cirugía oral de la Facultad de Odontología de la Universidad Nacional de Colombia y la frecuencia de aparición de quistes dentígeros, rango de edad, sexo y la región anatómica en que predominan. Métodos: se revisaron 17 sacos foliculares de 11 pacientes atendidos en las clínicas de cirugía oral entre agosto del 2018 y febrero 2019. Resultados: se recolectaron 7 biopsias de 5 pacientes masculinos  y 10 de 7 pacientes femeninos, con edades comprendidas entre los 17 a 24 años (media: 20.40), se realizó estudio histopatológico con hematoxilina-eosina, los datos obtenidos se analizaron para determinar frecuencia, edad, sexo y patología asociada. Se encontraron 15 casos que mostraron cambios quísticos diagnosticados como quistes dentígeros y  2 casos diagnosticados como saco folicular. Conclusiones: aunque la muestra es pequeña, este estudio da indicios que los sacos foliculares asociados a terceros molares incluídos están  altamente implicados en la formación de quistes dentígeros.

Evaluación radiográfica de la estabilidad en medidas cefalométricas de pacientes Clase III sometidos a cirugía ortognática bimaxilar*

Objetivo: evaluar cefalométricamente en los planos sagital y vertical la estabilidad de pacientes con maloclusión clase III sometidos a cirugía ortognática bimaxilar. Métodos: estudio longitudinal en 20 pacientes (11 mujeres), con un promedio de 22.5 años y diagnóstico de hipoplasia del tercio medio facial y prognatismo mandibular, tratados con ortodoncia y cirugía ortognática bimaxilar. Se realizaron tres radiografías cefálicas laterales por cada paciente: una previa al procedimiento quirúrgico (T1), otra a los 8 meses posquirúrgicos (T2) y a los 18 meses posquirúrgicos (T3). Se evaluaron los cambios en el plano X y Y en los tres tiempos, realizando las pruebas estadísticas pertinentes con el fin de observar diferencias. Resultados: se encontraron medidas más estables en el maxilar superior en sentido vertical y sagital, mientras que la mandíbula es menos estable a los movimientos quirúrgicos, principalmente en sentido vertical (diferencias estadísticamente significativas p<0.05) Conclusión: la cirugía ortognática bimaxilar en casos de clase III es muy estable (especialmente en el maxilar); dicha estabilidad fue definida solamente con medidas cefalométricas, sin tener en cuenta variables como la función o las características clínicas de los pacientes.

Comparative analysis between developmental and inflammatory odontogenic cysts: retrospective study and literature review

PURPOSE

To assess epidemiological, clinical, and radiographic characteristics of odontogenic cysts (OCs) in a South Brazilian sample and to compare the results with international literature.

METHODS

For the main study purposes, biopsy and histopathological records were retrospectively analyzed from December 2006 to December 2018, OC cases were selected, and data about clinical characteristics were evaluated. Further, a literature review was performed for similar studies.

RESULTS

In the main study, the prevalence of OCs was 11.26% (n = 406), the majority of patients was male (56.73%), and the mean age was 39 ± 17.33 years. Radicular cyst was the most common OC (46.06%), followed by the odontogenic keratocyst (15.02%), dentigerous cyst (14.04%), and paradental cyst (13.55%). Inflammatory OCs were more prevalent in the maxilla (54.84%) and developmental cysts in the mandible (69.92%) (p < 0.05). Individuals with inflammatory OCs were usually older (41.0 ± 15.34 years) than the ones with developmental OC (28.0 ± 19.68 years) (p < 0.05). Regarding the literature review, 22 articles were included. Analysis of pooled data showed that global prevalence of OCs was 11.62% (95%CI = 9.97-13.37), from which radicular cyst was the most common (54.26%; 95%CI = 49.30-59.18), followed by dentigerous cyst (22.94%; 95%CI = 19.22-26.89) and odontogenic keratocyst (11.99%; 95%CI = 8.88-15.49). Furthermore, studies from Asia (72.40%; 95%CI = 70.30-74.40) and South America (68.48%; 95%CI = 64.07-72.72) presented the highest frequencies of inflammatory OCs.

CONCLUSION

The main study showed that the prevalence of OCs was 11.26%, which corroborates with international literature. Considering geographic variability of OC distribution, public health authorities and researchers could use these data for the development of focused prevention interventions, especially with regard to inflammatory OCs.

Odontogenic Cyst From an Ectopic Supernumerary Tooth Impacted in the Orbital Floor

Objectives:

Supernumerary dentition has been found to occur in various areas of the head and neck. Although they are commonly found along the dental arch, there are some instances of ectopic supernumerary teeth found elsewhere in the upper aero digestive tract. This case report details an impacted molar tooth in the orbital floor.

Methodology:

We present an unusual case of a 30-year-old male with a chief complaint of nasal obstruction. Clinically, it was manifested with an impacted molar in the orbital floor with associated bony expansion into the maxillary and ethmoid sinuses.

Results:

Radiographically, CT scan revealed a benign appearing expansile mass in the left maxilla, completely occupying the sinus and extending into the nose and expanding laterally into the cheek. There appeared to be a well-formed tricuspid tooth clearly visible at the top of this lesion protruding into the left orbit. The patient underwent endoscopic surgical removal, showed findings of an impacted tricuspid in the medial and inferior walls of the orbit. Histopathologic examination confirmed a large cyst lined by thick stratified squamous epithelium and embedded with dense fibrous connective tissue, consistent with an orthokeratinized odontogenic cyst. The medial orbital wall was decompressed, and his postoperative course was uneventful with no orbital complications. Ectopic supernumerary teeth are unusual findings, particularly in association with the orbit. They are frequently impacted and as such can lead to the development of cystic lesions. As with other odontogenic cysts, surgery is usually definitive. This case study demonstrates complete removal with endoscopic surgery.

The World Health Organization classification of odontogenic and maxillofacial bone tumors: An appraisal

Classification is the process of grouping similar entities under one category for the ease of their comprehension and better handling. Medical classification dates back to the days of William Farr who is credited with the development of a nosology, which later served as the forerunner for the modern-day disease classification by ICD. The WHO system of classification is a time-honoured system that has prevailed from decades together and is under constant evolution. The classification of odontogenic tumours was first formulated by Pierre Paul Broca and has undergone several transformations over years. Though the earlier classifications and their modifications by several authors and even by the WHO appeared to be fitting for their time, the latest edition of WHO classification of odontogenic and maxillofacial bone tumours neither seems to be complete nor perfect, even at the present context. It is unfortunate that even with the advancement of molecular biology, the present WHO classification on Odontogenic and Maxillofacial bone tumours, fails to serve as a 'reference standard' in the true sense of the term. This article highlights the limitations of the current classification with constructive criticism that may help in further improvement.

Demographic and Clinical Characteristics of 5294 Jaw Cysts: A Retrospective Study of 38 Years

The aim of the present study is to report the demographic and clinical characteristics of all jaw cysts diagnosed in a single Oral Pathology Department. 5294 cases of jaw cysts diagnosed during a 38-year period were retrospectively collected and classified according to the latest classification of Head and Neck Tumors of the World Health Organization. The patients' gender and age, as well as the main clinical features of the cysts were retrieved from biopsy report forms. Jaw cysts were more common in male patients, with a male to female ratio of 1.6:1. Most patients were in the 4th-6th decade of life, with a mean age of 42.3 ± 16.1 years. There was no jaw predilection and the majority of lesions were more commonly encountered in the anterior region of the maxilla, followed by the molar region of the mandible. The most common jaw cyst was radicular cyst followed by dentigerous cyst, residual cyst and odontogenic keratocyst. The majority of jaw cysts are of inflammatory origin and represent a sequale of pulp necrosis. However, other type of jaw cysts may also be found.