Photobiomodulation Therapy Partially Restores Cartilage Integrity and Reduces Chronic Pain Behavior in a Rat Model of Osteoarthritis: Involvement of Spinal Glial Modulation.

OBJECTIVE: Chronic pain associated with osteoarthritis (OA) often leads to reduced function and engagement in activities of daily living. Current pharmacological treatments remain relatively ineffective. This study investigated the efficacy of photobiomodulation therapy (PBMT) on cartilage integrity and central pain biomarkers in adult male Wistar rats. DESIGN: We evaluated the cartilage degradation and spinal cord sensitization using the monoiodoacetate (MIA) model of OA following 2 weeks of delayed PBMT treatment (i.e., 15 days post-MIA). Multiple behavioral tests and knee joint histology were used to assess deficits related to OA. Immunohistochemistry was performed to assess chronic pain sensitization in spinal cord dorsal horn regions. Furthermore, we analyzed the principal components related to pain-like behavior and cartilage integrity. RESULTS: MIA induced chronic pain-like behavior with respective cartilage degradation. PBMT had no effects on overall locomotor activity, but positive effects on weight support (P = 0.001; effect size [ES] = 1.01) and mechanical allodynia (P = 0.032; ES = 0.51). Greater optical densitometry of PBMT-treated cartilage was evident in superficial layers (P = 0.020; ES = 1.34), likely reflecting the increase of proteoglycan and chondrocyte contents. In addition, PBMT effects were associated to decreased contribution of spinal glial cells to pain-like behavior (P = 0.001; ES = 0.38). CONCLUSION: PBMT during the chronic phase of MIA-induced OA promoted cartilage recovery and reduced the progression or maintenance of spinal cord sensitization. Our data suggest a potential role of PBMT in reducing cartilage degradation and long-term central sensitization associated with chronic OA.

Orthodontic tooth movement in immature apices: a systematic review / El movimiento dental ortodóncico en ápices inmaduros: revisión sistemática

ABSTRACT Introduction: orthodontic tooth movement with open apices which have not completed root formation has not been sufficiently studied. There is controversy about the risks associated to this movement, such as root resorption and decreased root length. The goal of this systematic review is to determine the possible effects of lengthening, shortening, or root resorption possibly occurring during orthodontic movement in teeth that have not completed root formation. Methods: electronic search (PubMed, Cochrane, Dentistry and Oral Sciences Source, Science Direct, Google Scholar, IdeA, ProQuest, Embase, Medline, Lilacs, TRIP) and manual search at Universidad El Bosque Juan Roa Vázquez Library since 1990 to 2014. Articles meeting the inclusion criteria, such as randomized clinical trials, prospective and retrospective studies, and studies in early mixed dentition with 2 x 4 system, were evaluated and methodologically qualified by four researchers. Results: this study involved a custom methodological rating taken from Lagravere et al (2005). Four articles were finally selected, three of which were retrospective: Amlani et al (2007), with 26 patients, found root resorption in 8% of the sample, with no statistical significance. Mavragani et al (2002), with a sample of 146 patients, found longer roots in younger teeth, and Kim & Park (2004), with 59 patients, found higher resorption in maxillary lateral incisors. Da Silva et al (2005), with 46 patients, reported a prevalence of 4.4% in root resorption in central incisors. Conclusions: this systematic review must be taken cautiously due to the low and moderate level of evidence found. In general terms, there were no alterations in terms of root length or shape when teeth with open apices were subjected to fixed orthodontic forces. The risk of apical resorption was more related to treatment duration in teeth with both open and closed apexes.

RESUMEN Introducción: el movimiento dental ortodóncico con ápices abiertos que no han terminado su formación radicular completa no ha sido estudiado suficientemente. Existe controversia sobre los riesgos que se pueden generar por dicho movimiento, como reabsorción radicular o disminución de la longitud radicular. El objetivo de esta revisión sistemática es determinar los posibles efectos de alargamiento, acortamiento o reabsorción radicular que se pudieran presentar durante el movimiento dental ortodóncico en dientes que no han terminado su formación radicular. Métodos: se hizo una búsqueda electrónica (PubMed, Cochrane, Dentistry and Oral Sciences Source, Science Direct, Google Scholar, IdeA, ProQuest, Embase, Medline, Lilacs, TRIP) y una búsqueda manual en la biblioteca Juan Roa Vázquez, de la Universidad El Bosque, desde 1990 a 2014. Los artículos que cumplieron con los criterios de inclusión, como ensayos clínicos aleatorizados, prospectivos, retrospectivos y de dentición mixta temprana con sistema 2 x 4, fueron evaluados por cuatro investigadores y calificados metodológicamente. Resultados: se realizó una calificación metodológica personalizada tomada de Lagravere y colaboradores (2005). Cuatro artículos fueron finalmente seleccionados, de los cuales tres fueron de modalidad retrospectiva: Amlani y colaboradores (2007), con 26 pacientes, encontraron reabsorción radicular en el 8% de la muestra, sin significancia estadística. Mavragani y colaboradores (2002), con una muestra de 146 pacientes, encontraron raíces más largas en dientes más jóvenes, y Kim y Park (2004), con 59 pacientes, encontraron mayor reabsorción en incisivos laterales maxilares. Da Silva y colaboradores (2005), con 46 pacientes, reportaron una prevalencia de 4.4% de reabsorción radicular en incisivos centrales. Conclusiones: esta revisión sistemática debe ser tomada con cautela por el bajo y moderado nivel de evidencia encontrado. En términos generales, no se encontró alteración en la forma ni en la longitud radicular cuando los dientes con ápices abiertos fueron sometidos a fuerzas ortodóncicas fijas. El riesgo de reabsorción apical estuvo más relacionado con la duración del tratamiento, en dientes con ápices tanto abiertos como cerrados.