Adult Temporomandibular Joint Research Articles

Classification for treatment of adult temporomandibular joint ankylosis and its secondary malformations

Classification for treatment of adult temporomandibular joint ankylosis and its secondary malformations

Alloplastic total joint replacement in management of temporomandibular joint ankylosis

Both autogenous and alloplastic material have been used in management of temporomandibular joint (TMJ) ankylosis. Second surgical site, donor site morbidity, possibility of over/undergrowth, graft fracture or resorption and increased surgical time are the disadvantages of autogenous graft. Alloplastic total joint replacement (TJR) has become a promising technique in management of adult temporomandibular joint ankylosis (TMJA). This paper intends to present the role of alloplastic TJR in management of TMJA. There is significant current evidence of the role of alloplastic TJR in the management of TMJA. Results in TMJA are excellent with sustained improvement in pain free mouth opening, correction of facial asymmetry, reduction in recurrence and improved quality of life. TMJ TJR is becoming the gold standard of care in the management of TMJA, although costs can sometime preclude access to this mode of therapy.

Evaluation of fit feasibility of stock total joint replacement in temporomandibular joint ankylosis patients

Long standing adult temporomandibular joint ankylosis (TMJA) results in smaller ramal height, and warped and undulated ramus. Despite the efforts made to standardise the sizes available in stock joint (Zimmer Biomet®), the system causes fit challenges in TMJA patients. The aim of the study was to evaluate the virtual feasibility of stock prostheses in TMJA patients. The data included amount of bone contouring for fossa placement, available ramal length, length discrepancy if placed straight, angulation of mandibular component required to adapt to the bone, and mediolateral fit discrepancy. CT data of 50 TMJA patients (71 joints; unilateral, n=29; bilateral, n=21; male, n=33; female, n=17) with mean age of 24.26±8.88 years were included. 53 joints required more than 3mm lateral bone reduction for fossa placement. The ramal length were categorised into ranges 35–40mm (n=15), 41–45mm (n=14), 46–50mm (n=28) and >50mm (n=14). Correlation between the age of occurrence of ankylosis and ramal length using the Pearson correlation coefficient revealed a positive correlation (r=0.38, p=0.001). Length discrepancy, angulation of mandibular component, and mediolateral fit discrepancy decreases as the ramal length increases. Only 14 joints had appropriate fit of stock prostheses while the remaining 57 joints warranted compromised placement. Even the smallest available stock mandibular component (45mm) had a compromised fit in terms of length and adaptability on the lateral aspect of ramus. The study concludes that a short ramus is mostly limiting factor in using stock prosthesis in TMJA patients. There is a need for still smaller size stock prostheses.

Outcome of Stock Total Joint Replacement With Fat Grafting in Adult Temporomandibular Joint Ankylosis Patients

Adult temporomandibular joint ankylosis (TMJA) lacks a uniform management protocol. The purpose of the study was to evaluate the outcome of stock total joint replacement (TJR) along with fat grafting around the joint in adult TMJA patients. Specific aim was to find out whether TJR can be a definitive management for adult TMJA. The investigators implemented a prospective study on adult TMJA patients treated with ostearthrectomy of ankylosis and stock temporomandibular joint (TMJ) TJR with fat grafting. Concomitant orthognathic correction of facial asymmetry was performed in some unilateral cases. Follow-up was carried out at regular intervals for assessing primary outcome variable of maximal incisal opening (MIO) and reankylosis. Secondary outcome variable included demographic data, etiology, duration of ankylosis (DOA), correlation between DOA and preoperative and postoperative MIO, occlusion and complications of hemorrhage, facial nerve paresis, periprosthetic joint infection, dislocation, and implant failure. The study sample was composed of 41 patients (54 joints) (bilateral, n=13; unilateral, n=28 [right side, n=12; left side, n=16]). The number of recurrent cases was 15. Trauma as etiology of ankylosis was seen in n=30 (73.2%), infection in n=7 (17.1%), unknown in n=3 (7.3%), and ankylosing spondylitis in n=1 (2.4%) cases. Mean DOA was 11.95years. Paired t test revealed a statistically significant difference between preoperative and follow-up MIO (P < .001). None of the cases showed reankylosis in the follow-up period. Pearson correlation revealed statistically negative correlation between DOA and postoperative MIO. The result of this study suggests that stock TMJ TJR along with fat grafting around the joints provides adequate mouth opening without any sign and symptoms of reankylosis. Stock TMJ TJR with fat grafting can be considered as a definitive treatment modality in adult TMJA with minimum comorbidity.

Is total joint replacement along with fat grafts a new protocol for adult temporomandibular joint ankylosis treatment?

Is total joint replacement along with fat grafts a new protocol for adult temporomandibular joint ankylosis treatment?

成人顎関節における内外側線維膜の立体超微形態学的研究

成人顎関節における内外側線維膜の立体超微形態学的研究

Factors affecting the variation in the adult temporomandibular joint of archaeological human populations

To elucidate factors that may affect the variation in the bony components of temporomandibular joint (TMJ), a preliminary study was conducted on the temporal articular surface of the TMJ of 30 skulls from Iron Age and medieval populations from Lithuania and a mixed Neolithic and Bronze Age population from the Central Elbe-Saale region (CESR). Using three-dimensional (3D) photos of the skulls, length and width measurements of the TMJ were obtained and compared with external skull measurements. Distinct, random variation between the TMJ values from opposite sides of the cranium were identified as fluctuating asymmetry. ANOVA results suggest significant differences in the length of the TMJ between the population of the CESR and the two Lithuanian populations, but not between the two Lithuanian populations. Environmental factors, including geography, may be responsible for the variation in the TMJ form.

Sensory Innervation of Temporomandibular Joint Disk

To investigate the nerve endings of the adult temporomandibular joint disk, in particular the presence and configuration of the sensory nerve endings by silver staining and electron microscopy. 20 cadaveric temporomandibular joints impregnated with silver stain were studied using an optical microscope; 2 other joints were studied using a transmission electron microscope. Free nerve endings were found in the disk parenchyma of all joints. Golgi-Mazzoni corpuscles, Ruffini corpuscles, and articular corpuscles were also observed as sensory nerve end organs. Myelinated and nonmyelinated nerve fibres were visualised in the disk parenchyma using the transmission electron microscope. Free nerve endings and sensory nerve end organs are present in the disk parenchyma of the human temporomandibular joint and are associated with sensation and proprioception, just as they are in the acetabular labrum, glenoid labrum, triangular fibrocartilage complex, and meniscus.

Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: A prospective longitudinal magnetic resonance imaging and cephalometric radiographic investigation

The aim of this prospective study was to analyze and compare the temporomandibular joint adaptive mechanisms in 25 adolescent and 14 young adult Class II malocclusions treated with the Herbst appliance. Temporomandibular joint remodeling was analyzed by magnetic resonance imaging. In each subject, 4 magnetic resonance images of both temporomandibular joints were available: before treatment, at the start of treatment (when the Herbst appliance was placed), during treatment (6 to 12 weeks after appliance placement), and after treatment (when the appliance was removed). Furthermore, effective temporomandibular joint changes (the sum of condylar remodeling, fossa remodeling, and condyle-fossa relationship changes) were analyzed with the aid of lateral cephalometric radiographs from before and after treatment. All subjects were treated to Class I or overcorrected Class I dental arch relationships, and their mandibles became significantly ( P < .001) more prognathic. After 6 to 12 weeks of Herbst treatment, signs of condylar remodeling were seen at the posterosuperior border in 48 of the 50 adolescent condyles and in 26 of the 28 young adult condyles. Bilateral remodeling of the mandibular ramus could be detected in 1 adolescent and 2 young adult patients. Signs of glenoid fossa remodeling at the anterior surface of the postglenoid spine were noted in 36 adolescent and 22 young adult temporomandibular joints. Effective temporomandibular joint changes during treatment were more horizontally directed and larger in both adolescents and young adult patients treated with the Herbst appliance than in an untreated group of subjects with ideal occlusion (Bolton standards). The increase in mandibular prognathism accomplished by Herbst therapy in both adolescents and young adults seems, in particular, to be a result of condylar and glenoid fossa remodeling. Because the Herbst appliance is most successful in Class II patients also at the end of the growth period, the treatment method could be an alternative to orthognathic surgery in borderline skeletal Class II cases. Magnetic resonance imaging renders an excellent opportunity to visualize the temporomandibular joint remodeling growth processes. (Am J Orthod Dentofacial Orthop 1999;115:607-18)

Three-dimensional Ultrastructural Study of Collagen Fibrils and Elastic Fibers in the Retrodiscal Tissue of the Human Adult Temporomandibular Joint

Three-dimensional Ultrastructural Study of Collagen Fibrils and Elastic Fibers in the Retrodiscal Tissue of the Human Adult Temporomandibular Joint

Development of nerve fibres in the temporomandibular joint of the human fetus.

The development of nerve fibres in the temporomandibular joint (TMJ) in relation to the development of bone, muscle and fibre components was investigated in human fetuses ranging from 9 weeks of gestation to birth. Immunohistochemistry for the glia-associated protein S-100 and for the neuro-specific marker protein gene product 9.5 (PGP 9.5) were used; specimens were compared to specimens of adult TMJ capsule and disc. At 9-10 weeks, a small number of neural elements are already present in the connective tissue around the joint and in the mesenchyme between the two articular blastemas from which the disc will differentiate. By 19 weeks many nerve fibres are clearly visible. Immunohistochemical results suggest diffuse disc innervation extending along the entire disc but not in the thin central area. More complex structures, i.e. encapsulated corpuscles, were also seen. The fetal disc appears highly innervated compared to adult tissue; already at this developmental stage morphology and distribution of nerves and corpuscles in the joint capsule are comparable to those in the adult joint. It may be concluded that the innervation of the TMJ is detectable from the end of the second month and that it develops fully between the third and the fifth month of gestation. Nerve endings in the disc are most numerous at 20 weeks, after which a progressive reduction, possibly secondary to the growth of articular tissues, is observed throughout the last trimester of fetal life and into adult life. The innervation of the lateral pterygoid muscle, on the contrary, is much less than that seen in adult muscles, even at full-term.

Relationship of articular soft tissue contour and shape to the underlying eminence and slope profile in young adult temporomandibular joints

This study examined whether the overall shape of the articular soft tissue overlying the posterior slope and articular eminence of the temporal bone could be predicted by the underlying osseous contour in a histologic model of 51 central sagittal sections of young adult temporomandibular joints. Articular soft tissue and bone contours were traced, and osseous landmarks identified on the basis of joint geometry. Soft tissue thickness measurements were made under low power light microscopy. Seven categories of articular soft tissue pattern were identified. The soft tissue uniformly followed the osseous contour in only one (14%). A progressive increase in soft tissue thickness from the middle of the posterior slope to the articular crest was the most common pattern (35%) but did not describe most of the sample that was more asymmetric. Pattern was poorly perdicted by the shape and slope of the temporal bone outline or by dental factors that describe anterior guidance and did not relate to disk displacement. The articular soft tissue compensated for flatter eminence slopes and osseous irregularities and maintained an intact surface. This study has clinical implications for radiographic interpretation of disk space, condyle translation pathways, and the integrity of the functional articular surface.

The effects of induced dental malocclusion on the fibrocartilage disc of the adult rabbit temporomandibular joint

Unilateral cast occlusal splints were fitted to the mandibular posterior teeth of adult rabbits, for periods of 1–28 days. The reactivity of the mandibular disc was examined by the effect on cell proliferation across the anterior, intermediate and posterior discal bands, as measured by metaphase arrest using vincristine sulphate. The effect on the disc was to activate cell proliferation on the splinted side. Intensity of response varied according to the length of time after fitting the splint, and the site involved. The findings suggested that the adult mandibular disc may participate in compensatory change at a cellular level and thus respond to changing functional loads placed upon the adult temporomandibular joints.

Serial variation in histological character of articular soft tissue in young human adult temporomandibular joint condyles

Histological variation was studied in serial sections, in contrast to previous studies which have generalized from representative sections. The sample consisted of consecutive serial sagittal sections from the central third of nine condyles, plus an accompanying stone cast showing the intact articular surface before sectioning. The thickness of the articular soft tissue and its fibrous connective tissue and cartilage components was measured, and the presence of undifferentiated mesenchymal (UM) cells was assessed by low-power light microscopy. Components of variance analysis showed that section-to-section variation in thickness was of the same order as differences between joints, each explaining approx. 50% of the variance in both connective tissue and cartilage thickness. The fibrous connective tissue contributed as much to the overall variation in soft tissue thickness as did the cartilage component (SD 0.0946 versus 0.0909 mm for the superior sector). Serial UM cell variability was common, and the UM cells were often distributed in islands rather than uniformly across the articular tissue. Condyles with the greatest surface irregularity were characterized by greater serial variability in fibrous connective tissue thickness, more frequent absence of cartilage, and more areas of UM cell depletion. These results suggest that serial variation in histological character may be more important than mean values in the description of surface contours and articular tissue relations in the temporomandibular joint. This should influence the design of future investigations.

Temporomandibular joint adaptation following inferior repositioning of the maxilla in adult monkeys.

Treatment of adults with vertical maxillary deficiency (short faces) has continually been an intriguing challenge for surgeons and orthodontists. For this category of patients, the introduction of simultaneous bone grafting and Le Fort I osteotomy has opened the door for improved treatment. However, despite the improved surgical techniques, surgeons have been reluctant to increase the vertical dimension of the maxilla by Le Fort I osteotomy with interpositional bone grafts because of inconsistent and variable stability after surgery. This study examines structural and functional adaptation of the adult temporomandibular joint and stability in a primate model following surgical lengthening of the maxilla in the vertical dimension. Results suggest that maxillary surgery and autorotation can alter condylar stress within physiologic ranges. However, further studies are indicated to clarify the surgery's long-term effect.

Repair of the adult temporomandibular joint meniscus with an autogenous dermal graft

A surgical procedure for the successful repair of the temporomandibular joint meniscus is described. Twenty-three patients have been treated by this procedure, with both objective and subjective improvement. The procedure is accomplished with minimal technical difficulty and minimal cosmetic defect.

Repair of the adult temporomandibular joint meniscus with an autogenous dermal graft

A surgical procedure for the successful repair of the temporomandibular joint meniscus is described. Twenty-three patients have been treated by this procedure, with both objective and subjective improvement. The procedure is accomplished with minimal technical difficulty and minimal cosmetic defect.

Histologic analysis of temporomandibular joint adaptation to protrusive function in young adult rhesus monkeys (Macaca mulatta)

It is generally believed that the adult temporomandibular joint is incapable of a significant adaptive response to forces produced by functional jaw orthopedics. To evaluate this view, twelve young adult female rhesus monkeys were fitted with functional protrusive appliances for periods ranging from 2 to 24 weeks. Histologic analysis of the temporomandibular joint demonstrated that six of the experimental animals exhibited a tissue response that was qualitatively similar to that noted in juvenile animals. However, the response in young adults was greatly reduced in magnitude from that seen in juveniles and was not related to duration of treatment. It must also be noted that three adult animals developed cross-bites in response to appliance placement, and three animals who functioned anteriorly exhibited little or no detectable condylar response. This study indicates that while some adaptive capability may still be present in the temporomandibular joints of young adults, the potential magnitude of the joint response is limited and highly variable in occurrence.

Neuromuscular and skeletal adaptations to altered function in the orofacial region

The purpose of this study was to investigate the nature of intrinsic musculo-skeletal adaptations resulting from experimental alteration of the orofacial environment. A new occlusal configuration was devised which modified oral sensory stimuli, subsequently prompting anterior positioning of the mandible of rhesus monkeys ( Macaca mulatta) during functional jaw movements at four defined stages of maturation. Specific skeletal, dental, and neuromuscular adaptations were studied and interrelated by means of serial electromyography, serial cephalometric radiography with metallic implants, and microscopic analysis. The study was divided into two time periods. During the 13-week control period, normal growth data were gathered from the four age groups. During the 13-week experimental period, specific neuromuscular and skeletal alterations caused by the experimental conditions were identified. Postural activity in the muscles of mastication and presumably the postural position of the mandible were altered by the induced changes in the oral environment. The superior head of the lateral pterygoid gradually increased in activity, first during functional movements and then during the maintenance of mandibular postural position. The superior head appeared to function as a principal forward positioner of the mandible. This activity decreased or disappeared by the end of the experiment. At the end of the experimental period, ten of the twelve experimental monkeys demonstrated an anteroposterior alteration in molar relationship. No single adaptive process could be isolated and identified as the sole cause of any effective alteration in maxillomandibular relationship at any age level. Rather, each resulting relationship was the composite of specific complementary (and occasionally antagonistic) adaptations throughout the craniofacial complex. Mandibular skeletal adaptations occurred primarily in the infant and juvenile animals in which the extent and direction of growth at the condyle were altered. Dentitional adjustments in the mandible were most notable in the adolescent and adult animals. In the nasomaxillary area a decrease in the vertical displacement of the maxillary complex was noted in all but three of the experimental animals. Horizontal displacement of the maxillary complex and the drift pattern of the maxillary dentition were also affected, but the expression of this effect was variable. After 13 weeks, little histologic evidence of physiologic or pathologic responses to the induced protrusive function was evident in the sacrificed animals. These histologic findings were consistent with past studies which suggest that the adult temporomandibular joint was stable and resistant while the growing articulation was responsive to functional changes. The results of this study further indicated that a chronologic correlation existed between the occurrence and disappearance of altered neuromuscular function and the re-establishment of skeletal balance. As skeletal balance was restored through specific structural adaptations, the need for compensatory muscle function was reduced. Further, the nature and extent of the specific skeletal and dental adaptations depended upon the level of maturation of the animal.

Alterations in the temporomandibular joint

A histologic and radiographic study of seventeen adult temporomandibular joints was initiated in order to assess factors which may contribute to alterations in joint morphology. Disc perforation was found in five of the specimens, particularly those from females. One case in particular demonstrated a drastic alteration of condylar form which appeared to be associated with a large defect in the articular disc. The extent of this remodeling was not revealed by lateral oblique radiographic projections but was demonstrated by radiographs which outlined the condyle in the near-frontal plane.