A. Viswanath

Temporomandibular Joint Osteoarthritis: Diagnosis and Long-Term Conservative Management: A Topic Review

Degenerative joint disease (DJD), a common osteoarthritic problem encountered in clinical practice presents as a chronic debilitating disease resulting in altered joint structure due to degradation and loss of articular cartilage, along with changes in the subchondral bone and other soft tissues. DJD is a frequent finding in the Temporomandibular joints (TMJs). Consequently, a good understanding of the use of a diagnostic algorithm will lead to a better control of DJD in the TMJ. The etiopathogenesis of osteoarthritis is complex, and it is associated with multiple risk factors. The condition progresses slowly through different phases with periods of remission and activity finally reaching the burnout phase. Conservative management forms the cornerstone for the treatment of most of these cases. This review attempts to acquaint the dentist with the diagnosis, pathogenesis and general characteristics of the disease while highlighting and updating them with the current conservative treatment algorithms in order to assist in the formulation of a treatment plan for these patients.

Trigeminal nerve injury following accidental airbag deployment and assessment with quantitative sensory testing

Abstract High velocity motor vehicle accidents are associated with an increase in mortality rates and a significant number of facial injuries. Accidental deployment of airbags and the associated release of hot gases can result in both thermal and mechanical injuries. The more commonly reported maxillofacial injuries include temporomandibular joint fractures and dislocations,1 dental trauma,2 facial nerve paralysis, 3 and other orofacial pain complaints. The following case report describes a patient with facial trauma from the accidental deployment of an airbag resulting in complaints consistent with a neurological injury for which quantitative sensory testing was used in confirming the diagnosis.

Biomechanical evaluation of different osteosynthesis methods after mandibular sagittal split osteotomy in major advancements

The aim of this study was to assess the biomechanical stability of six different osteosynthesis methods after sagittal split osteotomy. Sixty polyurethane hemimandibles were divided into two groups, with six subgroups in each. After 10-mm advancement of the distal segment (group 1) and 10-mm advancement combined with 20° counterclockwise rotation (group 2), the bone segments were fixed using 2.0-mm plates/screws as follows: subgroup A, one conventional straight plate; subgroup B, two conventional straight plates; subgroup C, one conventional sagittal plate; subgroup D, one locking straight plate; subgroup E, two locking straight plates; subgroup F, one locking sagittal plate. The hemimandibles were tested for compressive strength by three-point biomechanical test, until there was 3mm of displacement between the segments. The fixations showed better performance in group 1 than in group 2 in all cases, with statistical significance for subgroups A, C, and D. In both groups, the use of two straight miniplates showed the most resistance, followed by the sagittal miniplates. However, in counterclockwise rotations, no statistically significant difference was found between two conventional straight plates and the sagittal locking plate. This study shows that the use of two plates is the form of fixation with the minimum displacement. If the clinician opts to use one plate, a sagittal plate is the best alternative.

Mouse model demonstrates strain differences in susceptibility to opioid side effects

Individual differences have been observed in responses to opioid drugs, including common side effects. In this study, the inbred mouse strains A/J and C57BL/6J were used to determine whether their specific strain differences correlate with differences in susceptibility to respiratory depression and constipation. To measure the effects of morphine on respiration, morphine at 15 and 40 mg/kg was injected subcutaneously. Respiratory parameters were then measured 30 and 60 min later. To measure the effects on constipation, 5, 15, 40, and 60 mg/kg doses were administered subcutaneously three times daily for three days. Gastrointestinal transit distance was then measured using the charcoal bolus test. C57BL/6J mice showed a greater degree of change in several respiratory parameters, resulting in more pronounced respiratory depression. C57BL6J mice also showed significantly more constipation than A/J mice with 40 and 60 mg/kg morphine doses. This study demonstrates that the strain differences between A/J and C57BL/6J mice have a major effect on opioid-induced constipation and respiratory depression. These correlations are of great clinical interest, as they could lead to the development of methods for reducing side effects.

231 IL‐2, IL‐4, IL‐6, IL‐12, AND TNF ALPHA IN NEURITIS AND CHRONIC CONSTRICTION NEUROPATHIC PAIN MODELS IN THE RAT

Background and Aims: Perineural inflammation contributes to the development of neuropathic pain. The aims of the present study were to assess levels of pro and anti inflammatory cytokines secretion in models of neuritis and chronic constriction injury (CCI) induced neuropathic pain and to study the effects of direct application of these cytokines on the nerve. Methods: Rats Sciatic nerves were exposed either to oxidized cellulose saturated with inflammatory adjuvant producing perineural inflammation, or loose ligations causing both inflammation and nerve damage. Cytokines secretion levels were assessed employing ELISA (R&D, MN, USA), 2 hours, 4 hours, 3 and 8 day following the procedure, in the ipsilateral and in the contralateral nerves. Tactile allodynia and hyperalgesia, and heat allodynia were tested upto 8 days following application of IL-6, TNFa, IL-12, IL-2, IL4, PBS, and CFA. Results: In both models anti inflammatory cytokines were elevated ipsilaterally two hours following the procedure, and bilaterally after 4 hours. In the CCI model, IL-4 level were elevated ipsilaterally up to 8 days following the procedure. TNFa, was elevated ipsilaterally in both models after 4 hour. TNFa and IL-6 were elevated bilaterally after 3 days. In CCI model TNFa and IL-6 levels remained high 8 days following the procedure. Conclusions: In both models, pro inflammatory cytokine secretion correlates with the pain behavior, up to three days in the neuritis model and longer in the nerve damage model. The absence of anti inflammatory cytokines 3 and 8 days following the procedure, may contribute to neuropathic pain development.