ABSTRACT: Head and neck malignant neoplasms are usually treated with surgery combined with radiotherapy, causing alterations in the maxillofacial structures, leaving sequelae in the tissues related to the temporomandibular joint (TMJ) and associated muscles. The literature is not clear about the pretreatment evaluation and diagnosis of cancer patients or their correct evaluation, so the diagnoses could be wrong. An scoping review of the literature was carried out presenting the most up-to-date information regarding the diagnoses and relevant outcomes of temporomandibular disorders (TMDs) in patients treated with radiotherapy for head and neck cancer. Four (4) electronic bibliographic databases were reviewed including original articles in English from January 2010 to July 2020 focused on the evaluation and diagnosis of TTMs and morphofunctionally associated tissues in a narrow group of patients. 353 articles were found that applied the inclusion and exclusion criteria. 7 relevant articles for evaluation. The association between the degree of exposure to radiotherapy and the molecular changes in the tissues that induce mandibular hypometry may be debatable due to not considering a careful study of the TMJ and its associated tissues, nor a specific pre-radiotherapy diagnosis to determine the preexistence of some TMD, inducing its aggravation or perpetuation. The literature is not explicit regarding the signs and symptoms associated with a correct examination of the temporomandibular joint and associated structures prior to radiotherapy. Trismus is only a sign of functional alteration of the stomatognathic system, but not a diagnosis in itself, which must be made based on standardized criteria and performed by an Orofacial Pain Specialist. To our knowledge, this is the first review that attempts to summarize the most current and relevant evidence on the diagnoses of temporomandibular disorders other than “trismus” in this group of patients.

RESUMEN: Las neoplasias malignas en cabeza y cuello son usualmente tratadas con cirugía combinada con radioterapia en algunos casos, provocando alteraciones en las estructuras maxilofaciales, dejando secuelas en los tejidos relacionados a la articulación temporomandibular (ATM) y la musculatura asociada. La literatura no es clara sobre la evaluación y diagnóstico pretratamiento del paciente oncológico ni su correcta evaluación, por lo que los diagnósticos podrían estar errados. Se realizó una revisión sistemática exploratoria de la literatura presentando la información más actualizada respecto a diagnósticos y alcances relevantes sobre trastornos temporomandibulares (TTMs) en pacientes tratados con radioterapia por cáncer de cabeza y cuello. Se revisaron 4 bases bibliográficas electrónicas incluyendo artículos en inglés originales de enero de 2010 a julio de 2020 enfocados en la evaluación y diagnóstico de TTMs y tejidos asociados morfofuncionalmente en estre grupo de pacientes Se encontraron 353 artículos que aplicados los criterios de inclusión y exclusión se obtuvieron 7 artículos pertinentes para evaluación. La asociación entre el grado de exposición a radioterapia y los cambios moleculares en los tejidos inductores de hipometría mandibular puede ser discutible debido a no considerar un estudio acucioso de la ATM y sus tejidos asociados ni un diagnóstico específico preradioterapia para determinar la preexistencia algún TTM, induciendo su agravamiento o perpetuación. La literatura no es explícita respecto a los signos y síntomas asociados a un correcto examen de la articulación temporomandibular y estructuras asociadas preradioterapia. El trismus es sólo un signo de alteración funcional del sistema estomatognático, pero no un diagnóstico en sí el que debe ser realizado en base a criterios estandarizados y realizado por un Especialista en Dolor Orofacial. Hasta donde sabemos, esta es la primera revisión que intenta resumir la evidencia más actual y relevante sobre los diagnósticos de trastornos temporomandibulares diferentes a “trismus” en este grupo de pacientes.

Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.