Alloplastic total temporomandibular joint replacements: do they perform like natural joints? Prospective cohort study with a historical control

The aim of this study was to qualitatively and quantitatively describe the biomechanics of existing total alloplastic reconstructions of temporomandibular joints (TMJ). Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via dynamic stereometry technology. This non-invasive method combines three-dimensional imaging of the subject's anatomy with jaw tracking. It provides an insight into the patient's jaw joint movements in real time and provides a quantitative evaluation. The patients were also evaluated clinically for jaw opening, protrusive and laterotrusive movements, pain, interference with eating, and satisfaction with the joint replacements. The qualitative assessment revealed that condyles of bilateral total joint replacements displayed similar basic motion patterns to those of unilateral prostheses. Quantitatively, mandibular movements of artificial joints during opening, protrusion, and laterotrusion were all significantly shorter than those of controls. A significantly restricted mandibular range of motion in replaced joints was also observed clinically. Fifty-three percent of patients suffered from chronic pain at rest and 67% reported reduced chewing function. Nonetheless, patients declared a high level of satisfaction with the replacement. This study shows that in order to gain a comprehensive understanding of complex therapeutic measures, a multidisciplinary approach is needed

Intermittent intracranial condylar dislocation with minimal functional sequelae-a case report

Degenerative changes of the temporomandibular joint (TMJ) present with a broad spectrum of morphological alterations. However, erosions leading to a glenoid fossa defect and condylar impingement of the temporal lobe are a rare finding. A 77-year-old female patient presented with limited mouth opening and pre-auricular pain during mastication on the left side. She denied any neurological dysfunction. Her medical history included poliomyelitis, multiple cancers, and osteonecrosis of the left tibial plateau. Computed tomography revealed advanced degeneration of both TMJs. On the left side, a glenoid fossa fragment was elevated towards the left middle cranial fossa. Real-time dynamic magnetic resonance imaging (MRI) showed repetitive intracranial condylar dislocation during mouth closure. She declined surgery and received instructions for self-management. At the 12-month follow-up, she reported resolution of the pain and normal masticatory function. A control MRI showed a stable radiographic appearance. This report illustrates that intermittent dislocation of the mandibular condyle into the middle cranial fossa can be successfully managed conservatively. The self-limiting nature of the TMJ degenerative joint disease, patient preference, and the patient's general health status require consideration when advising patients on the therapeutic strategy

The incidence of osteoarthritic change on computed tomography of Korean temporomandibular disorder patients diagnosed by RDC/TMD; a retrospective study

Objective Osteoarthritis (OA) of the temporomandibular joint (TMJ) is generally thought to be an age-related disease like those of other joints. This study aims to investigate the incidence of computed tomographic (CT) OA changes in Korean temporomandibular disorder (TMD) patients diagnosed by the Research Diagnostic Criteria for TMD (RDC/TMD). Materials and methods The clinical records and radiographs of 1038 TMD patients (297 men and 741 women with mean age 31.1 ± 17.4 and 34.0 ± 16.2, respectively) diagnosed based on RDC/TMD Axis I in 2010 were reviewed. Results The incidence rate of OA changes in TMD patients is estimated to 27.3%, and higher in women than in men (15.5% in men and 32.0% in women) by 2.3 odds (p < 0.001). It has no correlation with age, showing an almost flat incidence rate throughout the age from the 2nd decade and has no correlation as well with pain or disc displacement diagnosed according to RDC/TMD, while arthrosis/arthritis diagnosis based on RDC/TMD supplemented by plain radiographs shows high risk of OA changes on CT by 38.8 odds (p < 0.05). Conclusions These results imply that the OA changes in young Korean TMD patients are as common as in the old and have no correlation with clinical pain and noise. Considered with high prevalence of TMDs known in the young population, the overall/absolute OA changes in the TMJ can be even higher in the young than in the old population, not like in other joints

In-vivo kinematic assessment of alloplastic temporomandibular joint replacements by means of helical axis: A cohort study with historical control

Alloplastic total temporomandibular joint replacement (TJR) is a surgical procedure used to restore normal mandibular function when conservative therapies fail. The instantaneous helical axis (HA), is a mathematical model used to visualize globally rigid body kinematics. It can be applied to mandibular motion for quantification of movement patterns and irregularities. Aim of this study was to analyze HA pathways in subjects with unilateral and bilateral TJR and compare them to a control group. An optoelectronic system was employed to track mouth opening/closing cycles (n = 3) of 15 patients (7 operated unilaterally, 8 bilaterally, 11 F, aged 24-72) and 12 controls (6 F, aged 23-40). HA position in space was determined for 30 equally-distributed steps of the observed movement. Total mandibular rotation around HA (Φtot) and total translation along HA (Ttot) were determined. Angles between HA and the anatomical coordinate system of the head (θx, θy, θz); global fluctuation of HA spatial orientation (θe), distance between condylar center (CP) and HA (dCP) and its projections on the axes (xdCP, ydCP, zdCP) were calculated. Overall, Φtot was larger in controls than in bilaterally operated subjects (p = 0.002, p = 0.003) and θz was larger in unilaterally operated subjects than in controls (p = 0.004) and bilaterally operated subjects (p = 0.002, p = 0.024). During opening, θe¯ was smaller in controls than in unilaterally operated subjects (p = 0.01). The distance dCP was smaller for alloplastic joints than for controls (p < 0.01 overall). In conclusion, mandibular HA pathways in patients with TJR differ significantly from controls in terms of spatial location and variability

Quality of life, chronic pain, insomnia, and jaw malfunction in patients after alloplastic temporomandibular joint replacement: a questionnaire-based pilot study

Studies of patients undergoing alloplastic total temporomandibular joint replacement seldom report on quality of life (QoL) and sleep. The aim of this pilot study was to assess these factors in such a patient cohort using validated psychometric questionnaires. Data were collected via online surveys comprising the following six questionnaires: Short Form-12 Health Survey (SF-12), Patient Health Questionnaire-15, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, Insomnia Severity Index, Graded Chronic Pain Scale, and Jaw Disability List. Pain intensity, limitation in nutrition, and treatment satisfaction were assessed using numerical rating scales. Mouth opening was measured at follow-up. The SF-12 Physical Composite Score was markedly lower than that of the age-matched general population, whereas the Mental Composite Score did not differ significantly. Participants indicated a low somatization level and low level of disability due to pain, but reduced QoL. Clinically relevant insomnia was reported by 36% of participants. In conclusion, the results of this pilot study indicate that QoL and sleep in patients with a total temporomandibular joint replacement differ from those in the general population, indicating the need for a comprehensive outcome assessment utilizing validated psychometric tools in accordance with the current biopsychosocial model of chronic disorders

Integrativer Behandlungsansatz bei chronischen Kiefer- und Gesichtsbeschwerden

The interdisciplinary Orofacial Pain Unit at the Center of Dental Medicine of the University of Zurich celebrates its 15th anniversary. This article outlines the evidence-based integrative treatment concept with a focus on psychosocial aspects of pain. We exemplify how the evaluation and treatment by a pain psychologist complements the dental therapy. For example, self-management techniques can assist in reducing apprehension, worries and fears, which are often associated with an increased tone of the masticatory muscles. Manifestations include clenching and grinding of teeth, orofacial pain, and other less specific symptoms such as tinnitus. The clinical relevance is illustrated by selected case studies from routine clinical practice

Beschwerdevisualisierung und -quantifizierung mit webbasierter Symptom-Evaluation (WISE)

Die Diagnostik und Behandlung von Mund- und Gesichtsschmerzen sowie von Funktionsstörungen der Kiefergelenke bedarf einer differenzierten Patientenbetrachtung. In unserer interdisziplinären Schmerzsprechstunde wird seit über zwei Jahren eine eigenentwickelte webbasierte Symptom-Evaluation ("web-based interdisciplinary symptom evaluation" [WISE]) zur Erhebung einer problemfokussierten Anamnese eingesetzt. Von zuhause aus übermitteln Patienten den Behandelnden vor der Erstvorstellung detaillierte Angaben zu ihren Beschwerden in strukturierter digitaler Form. Den Behandelnden stehen die vorab erhobenen Patientendaten zusammengefasst zur Verfügung. Diese ermöglicht in Kürze eine Übersicht der Fallkomplexität, der Therapiedringlichkeit und des Ressourcenbedarfs (Zeitbedarf, zuständige Fachkompetenz). Für telemedizinische Beratungen in Pandemiezeiten sind mit der WISE umfassende quantitative Angaben übersichtlich verfügbar. Für wissenschaftliche Zwecke sind die Daten in strikt anonymisierter Form nutzbar. Insgesamt wird mit WISE eine personalisierte Medizin ermöglicht, die interprofessionelle Ausbildung und Zusammenarbeit erleichtert und eine multizentrische, patientenbezogene Forschung unterstützt

Short‐term effects of NTI‐tss and Michigan splint on nocturnal jaw muscle activity: A pilot study

Objectives: Sleep bruxism is mostly assessed by reporting of tooth-grinding or clenching during sleep and by clinical signs (tooth wear, cracks, or fractures). Parafunctional tooth damage is usually prevented by employing occlusal appliances mainly of the full arch covering type (Michigan splint) and of the partial type covering only central incisors (NTI-tss). To date, the effects of occlusal appliances on sleep bruxism or jaw muscle activity during sleep are still controversial. The present study is a randomized controlled clinical trial that evaluated the effects of two different splint designs on jaw muscle activity in sleep bruxers otherwise healthy. Material and methods: Ten patients from a private dental practice were treated by a single operator. A Michigan splint and an NTI-tss device were manufactured individually and used at random order. Electromyographic jaw muscle activity was recorded for four consecutive nights in the first, fourth, and seventh week with and without splint. Participants reported on splint comfort and side effects. Results: Muscle activity decreased only while wearing the NTI-tss device. Most patients preferred though the Michigan splint due to its greater wearing comfort. Conclusions: NTI-tss devices proved more effective for the reduction of jaw muscle activity during sleep. The main advantage of the prefabricated NTI-tss is its prompt availability in an acute phase of temporomandibular disorders associated with sleep bruxism. In long-term therapies, patients should be informed of the possible risk of irreversible occlusal changes. Subjective preferences, wearing comfort, and costs should also be considered