Biomechanics and Derangements of the Temporomandibular Joint.

The human temporomandibular joint, is a ginglymo-arthrodial joint. The articular disk serves as a fibrous, viscoelastic structure that allows force distribution and smooth movement of the joint in its normal arrangement during mandibular movements. Most studies suggest that in the normal disk position the posterior band is located at the 12'o clock position within the glenoid fossa in the closed mouth posture. When the biomechanics of the joint is altered, the disk may be displaced creating an abnormal relationship between the disk, condyle, and the eminence that is often referred to as an internal derangement. This article reviews the various presentations of internal derangements.

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

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, dental trauma, facial nerve paralysis, 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.

Prolonged gingival cold allodynia: a novel finding in patients with atypical odontalgia.

OBJECTIVE: The aim of this study was to examine atypical odontalgia (AO) patients with extraoral quantitative sensory testing (EQST) and an intraoral mucosal cold test. STUDY DESIGN: Twenty-one subjects with AO and 18 control subjects underwent EQST for electrical and thermal pain and detection thresholds. Cold was applied to painful mucosal areas in AO patients and randomly in control subjects. RESULTS: Electrical pain thresholds were higher in AO patients than in control subjects in the same dermatome affected by the pain (P = .03), but no significant differences were observed in electrical detection thresholds and heat pain and detection thresholds at other sites. Cold application was painful in control and AO subjects, but duration of pain sensation was significantly longer in AO patients (P = .019 in contralateral side; P = .029 in affected side). CONCLUSIONS: The finding of extended painful aftersensation following cold application in AO patients supports the involvement of central mechanisms. The cold test is clinically easy to apply and of clinically significant value.

Orofacial pain: basic mechanisms and implication for successful management.

Orofacial Pain is the field of dentistry devoted to the diagnosis and management of chronic, complex, facial pain and oromotor disorders. This specialty in dentistry has developed over a number of years out of the need for better understanding of a group of patients who somehow were not clearly suffering from dental pain disorders, but still did not seem to have a clearly defined medical problem. After a long period of treating patients based on the mechanicist aspect of the disease, our profession has realized the importance of basic knowledge and differencial diagnosis in order to proper manage these patients. This modification in the approach has caused severe changes in education as well as in clinical activities. Historically considered as a problem of occlusion, Orofacial Pain, including Temporomandibular Disorders (TMD) has recently reached the status of "Specialty" in Brazil. Therefore, this paper aims to discuss the main differences between musculoskeletal and neuropathic pain and the importance of basic knowledge to perform successful management.

Dores orofaciais: mecanismos básicos e implicaçöes para um tratamento efetivo / Orofacial pain: basic mechanisms and implication for successful management

Dor orofacial é um campo da odontologia dedicado ao diagnóstico e tratamento de dores orofaciais crônicas e complexas, além d e desordens motoras. Essa especialidade odontológica tem se desenvolvido por vários anos com o objetivo de prover um melhor entendimento de um grupo de pacientes que, de alguma forma, näo tinham dores de origem dentária e nem condiçöes óbvias médicas que explicassem suas dores na face. Depois de um longo período propondo tratamentos baseados apenas no aspecto mecanicista da doença, nossa profissäo percebeu a importância de entender mecanismos básicos de diagnóstico diferencial para melhor controlar esses casos. Essa mudança de mentalidade tem levado a modificaçöes na educaçäo em odontologia, assim como nos procedimentos clínicos executados. Historicamente considerada como um "problema de oclusäo", as dores orofaciais obtiveram recentemente o reconhecimento como especialidade em nosso país. Baseado nisso, o objetivo desse artigo é discutir diferenças básicas entre os tipos mais comuns de dor orofacial, assim como ressaltar a importância do conhecimento de mecanismos de conduçäo de dor para a formulaçäo de um plano de tratamento efetivo