Oral pathology and oral medicine in Latin American countries: current stage.

BACKGROUND: Oral Pathology (OP) and Oral Medicine (OM) are specialties in dentistry whose main objective is the diagnosis and treatment of oral and maxillofacial diseases, and aspects related to the academic training of professionals and fields of practice are distinct and heterogeneous around the world. This study aimed to evaluate professional training and areas of activity in OP and OM in Latin American countries. MATERIAL AND METHODS: A questionnaire was sent to 11 countries, with a professional in each country responsible for answering it. The questionnaire had 21 questions related to the process of professional training, areas of practice, the existence of scientific events in each country, and also collected demographic and population information. RESULTS: OP and OM are practiced in all the countries studied, but the specialty is not recognized in all of them. Brazil was the first to recognize both as a specialty. Postgraduate programs designed to train specialists are available in various countries. Two countries offer residency programs, 6 countries provide specialization courses, 6 offer master's programs, and 3 have doctoral programs. Brazil boasts the highest number of undergraduate courses (n=412), while Uruguay has the lowest (n=2). Professional societies representing the specialty exist in ten countries. Brazil has the highest number of OP and OM specialists (n=422 and 1,072), while Paraguay has the smallest number (n=1 and 3). CONCLUSIONS: Although both specialties are widely practiced around the globe, professional training, the number of dentists trained and the fields of professional practice are very different between the countries studied.

Perineural invasion predicts poor survival and cervical lymph node metastasis in oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) usually invades peripheral nerves through a process known as perineural invasion (PNI), recognized as an adverse factor considered for the administration of postoperative adjuvant therapy. The aim of this study was to assess the impact of PNI on survival and cervical lymph node metastasis in a cohort of OSCC patients. MATERIAL AND METHODS: Presence, location and extension of PNI were assessed in a cohort of 57 paraffin-embedded OSCC resections. Clinico-pathological variables were obtained from each case. Five-year overall survival (OS) and 5-year disease-specific survival (DSS) curves were constructed according to the Kaplan-Meier method and compared with log-rank test. The Cox proportional hazard model was used to assess the role of PNI as an independent risk factor related to poor survival, and a binary logistic regression was performed to estimate the predictive value of PNI for regional lymph node metastasis. RESULTS: PNI was observed in 49.1% of the cases, affecting only small nerves. Peritumoral PNI was the most common location, and multifocal PNI the most frequent extent. Most PNI positive cases had cervical metastasis (p=0.001), and PNI was more frequent in stages III-IV than in I-II (p=0.02). The five-year OS and the 5-year DSS decreased in PNI positive and peritumoral PNI cases. PNI was an independent risk factor for poor 5-year OS and poor 5-year DSS. The odds for cervical lymph node metastasis were of 6.076 (p=0.006) and 10.257 (p=0.007) for PNI and Tumor budding (TB) positive cases, respectively. CONCLUSIONS: PNI is a frequent finding in OSCC and an independent risk factor for poor OS and DSS. PNI and TB are both risk factors associated to an increased likelihood for the development of lymph node metastasis. Therefore, we suggest further investigations to test the combined PNI-TB scoring system in risk stratification models for OSCC.

Histopathological parameters reported in microinvasive oral squamous cell carcinoma: a systematic review.

BACKGROUND: Microinvasive oral squamous cell carcinoma (OSCCmi) is an incipient stage of oral cancer. Through this systematic review, we aim to assess patterns of histopathological outcomes reported in OSCCmi cases. MATERIAL AND METHODS: An online search in major databases was performed without period restriction, and 2,024 publications in English, Spanish and Portuguese were obtained. After screening and eligibility, 4 studies were selected. The risk of bias was assessed using Joanna Briggs Institute Critical Appraisal Checklist. A descriptive synthesis was conducted. RESULTS: All 4 publications included were retrospective, reporting a total of 116 OSCCmi patients, with a male predominance (1.6:1) and a mean age of 55.9 years. The main parameters considered for microinvasion were tumor thickness (TT) (range 4-10mm) and depth of invasion (DOI) (range 0,02-5mm). Definition, cut-off values, and assessment of microscopic features were not standardized. Other relevant measures such as perineural or lymphovascular invasion and pattern of invasive front were barely described, and cytological/architectural characteristics were not discussed. CONCLUSIONS: TT and DOI are currently the primary histopathological criteria used to define OSCCmi. Nonetheless, the outcomes of this systematic review showed the absence of standardized quantitative parameters to render the diagnosis of microinvasive OSCC. Therefore, additional studies aiming to standardize histopathological features to diagnose OSCCmi are paramount.

Estimulación nerviosa eléctrica transcutánea como complemento a la terapia convencional en pacientes con trastornos temporomandibulares: un estudio caso-control / Transcutaneous electrical nerve stimulation as a complement to conventional therapy in patients with temporomandibular disorders: a case-control study

INTRODUCCIÓN: Para los trastornos temporomandibulares (TTM) el tratamiento de primera línea es el conservador, éste incluye a la terapia convencional, además se ha descrito el uso de la estimulación nerviosa eléctrica transcutánea (TENS). El objetivo de este estudio fue determinar la respuesta terapéutica del TENS como complemento a la terapia convencional comparado con pacientes que recibieron exclusivamente terapia convencional. MATERIAL Y MÉTODOS: Estudio retrospectivo caso-control en pacientes diagnosticados con TTM, tratados en la Clínica de Especialidades de la Escuela de Odontología de la Universidad de Valparaíso, entre los años 2009 y 2012. De los 231 pacientes, 63 cumplieron con los criterios de inclusión y fueron pareados en un grupo convencional y un grupo TENS. Se evaluó el dolor articular y muscular; aperturas mandibulares activa sin dolor, activa forzada y pasiva; y fuerza masticatoria. Se aplicaron test estadísticos de Kruskal-Wallis, Wilcoxon y Spearman. RESULTADOS: Para el grupo TENS, se encontraron respuestas significativas en dolor articular y muscular derecho e izquierdo, apertura mandibular activa sin dolor y fuerza masticatoria. Para el grupo convencional, se encontraron resultados similares a excepción de dolor articular derecho. También respuestas significativas para todas las variables que midieron dolor inmediatamente posterior a la aplicación de TENS. Finalmente se establecieron correlaciones entre la edad y las aperturas activa sin dolor, activa forzada y pasiva. DISCUSIÓN: La terapia convencional y la complementada con TENS demostraron similar respuesta terapéutica a largo plazo, sin embargo, la aplicación del TENS produce una respuesta inmediata que reduce el dolor en el corto plazo

INTRODUCTION: For temporomandibular disorders (TMD), conservative therapies, including conventional therapy, are the first line of treatment, and the use of transcutaneous electrical nerve stimulation (TENS) has also been reported. The aim of this study was to determine the therapeutic response to TENS as complement to conventional therapy compared with patients receiving conventional therapy exclusively. METHODOLOGY: A retrospective study was carried out with patients diagnosed with TMD, treated at the Clinic of Specialties of the Dental School of Universidad de Valparaíso, between 2009 and 2012. Of 231 patients, 63 met the inclusion criteria and were randomly allocated to a conventional therapy group (controls) and a coadjuvant TENS group (cases). Both were evaluated for pain in the temporomandibular joints (TMJ) and masseters, active opening without pain, forced active opening, passive opening, and occlusal force. Statistical analysis was performed with Kruskal-Wallis, Wilcoxon and Spearman tests. RESULTS: For TENS group, significant differences were found for pain in the right and left TMJ, pain in the right and left masseter, active opening without pain, and occlusal force. For the conventional group, the same results were obtained, except for pain in right TMJ. For the variables measured immediately after applying TENS, significant differences were found in all pain variables. Correlations were established with age, active opening without pain, forced active opening, and passive opening. DISCUSSION: Conventional therapy and TENS-complemented therapy showed good therapeutic response, concluding that TENS is a good complement to conventional therapy

The impact of head and neck radiotherapy on the dentine-enamel junction: a systematic review.

BACKGROUND: Radiotherapy is widely used in contemporary head and neck cancer treatment protocols. The ability of head and neck radiotherapy (HNRT) to cause direct radiogenic destruction to the teeth is one of the most controversial topics in the field of oral oncology. Therefore, this systematic review aimed to investigate ionising radiation as an independent factor for physical and chemical changes on the dentine-enamel junction (DEJ), a pivotal dental topography for the onset and progression of radiation-related caries (RRC) and enamel delamination. MATERIAL AND METHODS: Systematic searches were conducted on three databases: Scopus, MEDLINE (Via PubMed) and Embase (Elsevier). Laboratory studies evaluating the effects of simulated or in vivo HNRT on the DEJ were included. The GRADE tool adapted for in vitro studies was used to assess the methodological quality. RESULTS: Of the 154 initially selected studies, eight met the inclusion criteria, from which five studies were graded as high quality of evidence, two studies were graded as moderate quality and one as low quality. Two studies did not demonstrate DEJ alterations following HNRT while the other six articles described several organic and inorganic changes in the DEJ of irradiated teeth samples. These radiogenic events were mostly detected through micro and nanoindentation, Raman micro-spectroscopy, confocal microscopy, Western blotting and optical coherence tomography. CONCLUSIONS: HNRT may have a negative impact on the physical and chemical aspects of the DEJ, predisposing cancer patients to RRC and enamel delamination.

Prognostic value of immunoexpression of CCR4, CCR5, CCR7 and CXCR4 in squamous cell carcinoma of tongue and floor of the mouth.

BACKGROUND: Diverse studies have evidenced that chemokines can play a critical role in pathogenesis of oral squamous cell carcinoma (SCC). The main chemokines involved in oral carcinogenesis, tumor invasion and metastasis are CCR4, CCR5, CCR7 and CXCR4, and our aim was to evaluate the prognostic value of the immunoexpression of these chemokines in SCC of tongue and floor of the mouth. MATERIAL AND METHODS: A retrospective descriptive study of the immunohistochemical expression of CCR4, CCR5, CCR7 and CXCR4 in paraffin-embedded samples of 124 patients with SCC of the tongue and floor of the mouth was performed, considering 98 cases from Brazil and 26 cases from Chile. Associations between variables were analyzed using chi-square test. Survival curves were performed using the Kaplan-Meier method and compared with long-rank test. For multivariate survival analysis, the Cox hazard model was established. The level of significance established was p≤0.05. RESULTS: The statistical analysis showed that samples with well or moderate WHO model differentiation (p=0.001) and a high expression of CCR5 (p=0.05) were significantly associated with a higher disease specific survival, which were also observed in Cox's multivariate analysis (p=0.01). A higher expression of CCR7 (p=0.01) interfered significantly in disease-free survival in univariate analysis and in Cox's multivariate analysis (p=0.05). CONCLUSIONS: These results support additional evidence, showing that chemokine receptors CCR5 and CCR7 are helpful as biomarkers of poor prognosis in patients with SCC of the tongue and floor of the mouth.