China
Africa
Explore chapters and articles related to this topic
Musculoskeletal system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
The temporomandibular joint (TMJ) is a synovial condyloid joint formed between the head (condyle) of the mandible and the mandibular fossa of the temporal bone (Fig. 3.50). The anterior part of the mandibular fossa, with which the head of the mandible articulates when the mouth is opened, is termed the articular tubercle. The joint capsule is attached superiorly to the rim of the articular surface and inferiorly to the neck of the mandible. The capsule is strengthened laterally to form the lateral or temporomandibular ligament. Intrinsically there is an interarticular disc (meniscus) that divides the joint into the superior and inferior cavities. It is attached to the periphery of the capsule and is situated over the head of the mandible, projecting anteriorly towards the tubercle. A number of small muscles combine to produce depression, elevation, protrusion, retraction and lateral movements of the mandible. These movements are complex, and the action of opening the mouth results in the head of the mandible moving downwards and forwards. Excessive movement can result in anterior dislocation of the head of the mandible on the articular tubercle. The joint derives its blood supply from the temporal and maxillary branches of the external carotid artery.
Designing for Head and Neck Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
The lower portion of the face, the jaw, provides protection as well as the motion essential for chewing and talking. The maxillae are the paired stationary upper jawbones which you can feel as a U-shaped structure holding your upper teeth. Each maxilla reaches all the way to the lower border of the eye and abuts the nasal bones medially and the zygomatic bone laterally. The mandible (lower jawbone), also U-shaped, is separate from the skull and holds the lower teeth. The temporomandibular joint (TMJ), the articulation between mandible and temporal bone, just in front of the ear canal, allows movement of the lower jaw so that you can talk and chew (inset, Figure 3.3). Keep the movement of the lower jaw (up, down, forward and back, and side-to-side) in mind when designing headgear that is strapped under the chin and/or worn while eating or talking.
Discrete Reduced Interference Distributions
Published in Antonia Papandreou-Suppappola, Applications in Time-Frequency Signal Processing, 2018
Many people have experienced the popping or clicking of a joint. Sometimes the temporomandibular joint (TMJ) clicks or pops when the jaw is moved. In many cases, this is a rare and harmless event. However, it may be indicative of a potentially serious condition. Such activity may be associated with a great deal of pain, perhaps even triggering headaches or other distressing symptoms. Even if one does not experience pain, these joint sounds may herald the development of more serious conditions. There is almost always someone in the audience with personal knowledge of pain and suffering from these problems, in terms of themselves, friends or family members when TF results are presented on these TMJ sounds. Previous work aimed at analyzing these signals has been spotty and mixed in results. Usually, the clinician simply listens to the sound and tries to report the results in some objective way. However, this method is highly subjective and often couched in terms such as likening the sound to “a dry stick breaking” or “the crunching of dry snow.” Arthritic joints, in particular, often produce creaking or crunching sounds. This is often called crepitation.
Morphological analysis of the temporomandibular joint in patients with anterior disc displacement
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Tinghui Sun, Bingmei Shao, Desmond Y. R. Chong, Zhan Liu
Temporomandibular disorders (TMD) are the most common issues when it comes to our jaw joints, sensitive bi-condylar joints that connect the mandible to the skull and regulate jaw movements during mastication, speech, expression, etc. There is a high prevalence of TMD in adults and the symptoms vary from mild discomfort to painful temporomandibular joint (TMJ) dysfunction. It was reported that 25% to 30% of the population has at least one TMD symptom (Solberg et al. 1979; Rugh and Solberg 1985; Koh and Robinson 2004) and the overall prevalence of TMD in females was much higher than in males with ratios varying from 2:1 to 8:1 in the different surveys (Solberg et al. 1979; Ingawale and Goswami 2009; de Godoi Gonçalves et al. 2010; Martins-Junior et al. 2010). Despite the high incidence of TMD, only a small amount of the patients would seek medical help, for the symptoms are mild at the early stage and many of them can be relieved spontaneously.
Comparison of stress distribution of TMJ with different mandibular deformities under incisal clenching
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Annan Li, Bingmei Shao, Zhan Liu
Temporomandibular joint (TMJ) is the only bilateral linked joint in the human body that plays a pivotal role in physiological functions, such as chewing, swallowing, speaking and so on. Besides, it is the most frequently used load-bearing joint and can be reshaped through the whole life (Palomar and Doblaré 2006; Liu et al. 2007a, 2008). Abnormal stress distribution caused by mandibular deformities can remodel the TMJs (Inui et al. 1999), and then lead to clinical signs and symptoms, such as temporomandibular disorders (TMD). Mandibular prognathism, retrusion and deviation are three common types of mandibular deformities in the population, with a prevalence percentage of 15–23.3% (Bergersen 1980; Bishara et al. 1994; Li et al. 2011). These deformities are relevant to the symptoms such as ankylosis of TMJs, dysfunction and arthritis with joint clicking and pain (Pirttiniemi 1994; Kobayashi et al. 1999; Kawai et al. 2020). On the other hand, they can also negatively affect the aesthetic appearance of the maxillofacial region and the patient's psychology health.
Numerical model proposed for a temporomandibular joint prosthesis based on the recovery of the healthy movement
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Henrique Takashi Idogava, Pedro Yoshito Noritomi, Gregory Bregion Daniel
The temporomandibular joint (TMJ) is a natural structure that connects the mandible to the skull. It is a bilateral synovial articulation between the temporal bone of the skull and the condyle of the mandible. This articulation has a very particular geometry, being composed by a superior fossa rounded at the base of skull where the condyle is fitted. Between the condyle and the fossa there is a cartilaginous disc that allows the movements. Many factors cause the substitution of this joint, such as accidents involving shocks, traumas, pathologies, congenital deformities of the condyle branch, bites with hard objects (Landes et al. 2013), rheumatic arthritis (Ahmed 2015), wear on the surface of TMJ (Mehra et al. 2009; Singh and Detamore 2009), bruxism (Seaton 1979), and osteoarthritis (Lee et al. 2017). Due to these problems, many patients are submitted to the surgical procedure to install condylar prosthesis in order to relieve chronic pain (Aagaard and Thygesen 2014).