Craniomandibular Articulation Research Articles

THE EFFICACY OF HIGH CONDYLECTOMY IN INTERNAL DERANGMENT OF THE TEMPOROMANDIBULAR JOINT

Background: Temporomandibular joint (TMJ) is a giglymoarthroidal Joint; it is the only mobile joint in the entire maxillofacial region and is a part of craniomandibular articulation.
 Methods: All the patients with internal derangement of temporomandibular joint having anterior disc displacement without reduction with complaints of pain and limited opening of mouth, of all age group reporting to the Department of Oral & Maxillofacial Surgery, GDC Jaipur were included in the study.
 Results: At one month follow up out of 20 patients 13 patients were not satisfied and at 6 month follow up 2 patients were not satisfied at all.
 Conclusion: We conclude that surgical treatment for internal derangement of the TMJ is required; this technique is effective to improve pain and mouth opening without complications. Although this study has a short follow up period and small sample size.
 Keywords: Mandible, Maxilla, TMJ.

Disconnecting bones within the jaw-otic network modules underlies mammalian middle ear evolution.

The origin of the mammalian middle ear ossicles from the craniomandibular articulation of their synapsid ancestors is a key event in the evolution of vertebrates. The richness of the fossil record and the multitude of developmental studies have provided a stepwise reconstruction of this evolutionary innovation, highlighting the homology between the quadrate, articular, pre-articular and angular bones of early synapsids with the incus, malleus, gonial and ectotympanic bones of derived mammals, respectively. There are several aspects involved in this functional exaptation: (i) an increase of the masticatory musculature; (ii) the separation of the quadrate bone from the cranium; and (iii) the disconnection of the post-dentary bones from the dentary. Here, we compared the jaw-otic complex for 43 synapsid taxa using anatomical network analysis, showing that the disconnection of mandibular bones was a key step in the mammalian middle ear evolution, changing the skull anatomical modularity concomitant to the acquisition of new functions. Furthermore, our analysis allows the identification of three types of anatomical modules evolving through five evolutionary stages during the anatomical transformation of the jawbones into middle ear bones, with the ossification and degradation of Meckel's cartilage in mammals as the key ontogenetic event leading the change of anatomical modularity.

Smile because of Dr Robert Murray Ricketts.

Smile because of Dr Robert Murray Ricketts.

Comment on “Computed Tomography Evaluation of Craniomandibular Articulation in Class II Division 1 Malocclusion and Class I Normal Occlusion Subjects in North Indian Population”

Clear statement of objective, appropriate location of landmarks and removal of subjective bias in measurement is essential in all kinds of research, especially, orthodontics. The research design should be rationalistic, purposeful, and in accordance with the objectives of the study. In this communication, we highlight the errors in research design, measurement, analysis, and inferences drawn with the help of a published article as the primary source to explain these simple but useful points.

Computed Tomography Evaluation of Craniomandibular Articulation in Class II Division 1 Malocclusion and Class I Normal Occlusion Subjects in North Indian Population

Objective. The purpose of this study is to investigate the Craniomandibular articulation morphology and position of condyle in mandibular fossae in Angle's class I normal occlusion and Angle's class II division 1 malocclusion. Materials and Methods. The present study was conducted on 40 subjects with 20 subjects in each group, and the computed tomography images were obtained using spiral computed tomography technique. Each measurement was compared by two-factor analysis of variance (ANOVA) while changes in anterior and posterior joint spaces were done by paired t-test. Results. Statistically significant anterior positioning of condyle (P > 0.05) was observed in class I normal malocclusion, and it was significant only on right side in class II division 1 malocclusion. Conclusions. There was no difference found in the condylar process and joint morphology between right and left sides of both Angle's Class I normal occlusion and Angle's class II division 1 malocclusion. Evaluation of the position of the condyles in their respective mandibular fossae showed concentric position with a tendency towards anterior positioning for both right and left sides of the subjects with Angle's Class I normal occlusion as well as subjects with Angle's class II division 1 malocclusion.

Anatomy of the Temporomandibular Joint

The temporomandibular joint (TMJ), also known as the mandibular joint, is an ellipsoid variety of the right and left synovial joints forming a bicondylar articulation. The common features of the synovial joints exhibited by this joint include a fibrous capsule, a disk, synovial membrane, fluid, and tough adjacent ligaments. Not only is the mandible a single bone but the cranium is also mechanically a single stable component; therefore, the correct terminology for the joint is the craniomandibular articulation. The term temporomandibular joint is misleading and seems to only refer to one side when referring to joint function. Magnetic resonance imaging has been shown to accurately delineate the structures of the TMJ and is the best technique to correlate and compare the TMJ components such as bone, disk, fluid, capsule, and ligaments with autopsy specimens.

The effect of posture change on the position of the skin marks for the transverse horizontal axis

Marks are placed on facial skin in clinical dentistry to indicate the position of more deeply placed landmarks or reference points. In this study the movement of the transverse horizontal axis skin points overlying the craniomandibular articulation were observed and quantified. The time taken for the skin displacement to occur when the posture changed between upright and supine was also studied. The extent of displacement of the skin point was approximately 3 mm in the sagittal plane and 2 mm in the frontal plane when the posture was changed from upright to supine and vice versa. The displacement was complete after 30 seconds in 95% of subjects. The direction of the displacement was primarily cephalad but with a dorsal component of more than 10 degrees in 87% of subjects. The extent of the movement in the sagittal and frontal planes was correlated. There was no gender difference for the skin displacement. Awareness by clinicians of the extent and direction of such facial skin movements can help to prevent errors.

Alteration of Vertical Dimension and Its Effect on Head and Neck Posture

Previous research has shown a relationship between head posture and rest position of the mandible. Should this relationship really be an interrelationship? Does a change in mandibular posture alone also alter head and neck posture? The purpose of this article is to demonstrate how a change in mandibular posture, specifically an increase in vertical dimension, contributes to craniovertical extension leading to suboccipital compression and upsetting the postural balance between the head and neck. A model of physiologic equilibrium is presented for the craniomandibular articulation.

An intraoral single-tray impression system to protect the craniomandibular articulation.

AbstractProtection of the craniomandibular articulation is critical during lengthy prosthetic procedures. The system described in this article can make accurate recordings of anatomic detail by providing an impression of the dentition while the patient's teeth are in a fully occluded position. The procedure is accurate and easily accomplished, and it is not traumatic to the tissues within the temporomandibular joint.

A combined tomographic-cephalometric analysis of the TMJ.

AbstractThe authors designed this analysis to serve as a tool for use in the study of growth and development of the craniomandibular articulation. It integrates an examination of the morphology and function of the temporomandibular joint with dento-skeletal characteristics according to pre-established cephalometric norms. The experimental sample consisted of 30 dental students with normal occlusions. Gnathologic principles, a tomographic study, cephalometric x-rays, submental vertex views, and temporomandibular joint space analysis were all correlated to provide a thorough and detailed approach to study of the joint.

Understanding temporomandibular biomechanics.

In all synovial joints normal function demands that sharp surface contact of the moving parts be maintained at all times. This is termed joint stability. Ordinary masticatory function imposes on the craniomandibular articulation a variety of mechanical forces which, if not counteracted, would separate the articulating parts and create a state of instability. An essential role of the articular discs is to maintain sharp contact of the joint surfaces during the full range of function—at rest as well as during empty-mouth movements, power strokes, and maximum intercuspation.The mechanism by which stability is maintained in the temporomandibular joints is unique and complex. A full understanding of mandibular function (and dysfunction) depends largely on accurate knowledge of the biomechanics by which the articular discs maintain joint stability. Applying such information at a clinical level brings new meaning to symptoms that identify disc interferences. This knowledge improves diagnosis and makes therapy more effective.

The Postnatal Development of the Temporomandibular Joint of the Common Marmoset (Callithrix jacchus)

The temporomandibular joints (TMJ) of 55 male and 50 female common marmosets (Callithrix jacchus) with an age range of 1 day- to < 12-yr-old have been studied to extend the knowledge on the craniomandibular articulation of this primate. Details of changes in the bone structure, gross and functional anatomy, and histologic appearance of the marmoset TMJ during the neonatal period, infancy, childhood, adolescence, and adulthood are compared with those which occur in the TMJ of man. It is concluded that further investigations on the structure and function of the marmoset TMJ and jaws may establish this nonhuman primate as a valuable analog for TMJ research in man.