Temporomandibular Joint Remodeling Research Articles

Arthrocentesis and intermaxillary traction appliance in a patient with unilateral posterior open bite caused by temporomandibular osteoarthritis : A Case Report

Osteoarthritis in the temporomandibular joint (TMJ) affects surrounding soft and hard tissues including cartilage, sub-chondral bone, and synovial membrane, causing TMJ remodeling and articular cartilage abrasion. When degenerative bone changes worsen in some patients with osteoarthritis, facial skeletal remodeling occur such as chin deviation, malocclusion. In patients with TMJ osteoarthritis, it is important to expand the joint space and decompress it. When pathological changes in the joint are observed, minimally invasive treatment such as intra-articular injection and arthrocentesis can be performed. An intermaxillary traction appliance can be applied for a short period of time to patients with TMJ osteoarthritis with oc-clusal changes. The purpose of this report is to review the case using arthrocentesis and intermaxillary traction appliance along with conservative treatment in a patient with unilateral posterior open bite caused by temporomandibular disorder(osteoarthritis), and to report the importance of appropriate diagnosis and treatment of temporomandibular disorder.

The effect of mandibular movement on temporomandibular joint morphology while eating French fries

BackgroundThe preferred masticatory side was reported to be almost always the same as the affected side of the temporomandibular disorder. Unbalanced alterations of temporomandibular joint morphology were found to be associated with unilaterally masticatory habits. The aim of this study was to investigate the effect of the mandibular movement on the remodeling of temporomandibular joint during eating French fries using a 3D motion capture system. MethodsTwelve volunteers with non-maxillofacial deformity and a healthy temporomandibular joint were recruited. The 3D models of the mandible and the maxilla were reconstructed according to computed tomography. The subjects were asked to eat French fries by unilaterally mastication, which was recorded by a 3D motion capture system. The trajectories of the incisors and the condyles and the condylar acceleration during unilateral mastication were analyzed. ResultsDuring incisal biting, there was no significant difference in the condylar trajectories between the left and right sides (P > 0.05). During unilateral mastication, the average displacement and acceleration of the masticatory condyles were significantly lower than those of the non-masticatory condyles (P < 0.05). The trajectory angles of the masticatory condyles were significantly steeper than those of the non-masticatory condyle (P < 0.05). During swallowing, there was no obvious movement of the mandible. ConclusionsBetween both temporomandibular joints, unilateral mastication resulted in significant differences in the regions of the condylar movement within the articular fossa, and then caused different compressive regions of the temporomandibular joints. Thus, unilateral mastication might result in a significantly different pattern of temporomandibular joint remodeling between the two sides.

Asymmetry of dental or joint anatomy or impaired chewing function contribute to chronic temporomandibular joint disorders

IntroductionThe etiologies of most chronic temporomandibular joint disorders are unknown. However, an association between habitual chewing on a particular side and chronic temporomandibular joint disorders has been reported.The aim of this study was to investigate the differences between sides (affected vs unaffected) of biodynamic factors (including lateral dental guidance determined by dental anatomy) or condylar path angles (determined by temporomandibular joint morphology) and chewing function (physiological alternate chewing vs single habitual chewing side). The study scope was to investigate possible etiological factors to improve the understanding of temporomandibular joint disorders.The null hypothesis was that no difference would be found between sides that are or are not affected by chronic temporomandibular joint disorders in chewing function or in levels of dental or temporomandibular joint remodeling. MethodsThis cross-sectional, double-blind study involved 24 adults with substantial, chronic, unilateral symptoms diagnosed as temporomandibular joint disorders. Chewing function, temporomandibular joint remodeling (using axiography) and dental anatomy (lateral guidance angles using kinesiography) were assessed. ResultsHabitual chewing on one particular side was observed in 17 of 24 participants; significantly more (n=15) chewed on the affected side than on the unaffected side (P=0.002 in a two-tailed Fisher’s exact test; risk estimate=4.5; 95% CI 1.326–15.277). The condylar path (CP) angle was steeper on the affected side than on the unaffected side (mean (standard deviation)=50.52° (9.98°) versus 45.50° (7.98°); P=0.002 in a two-tailed t-test). The lateral guidance (LG) angles were flatter on the affected side in all 24 participants. ConclusionOur results suggest that habitual chewing on one side may be associated with increasing condylar path, with flattening lateral guidance angles, and also with chronic temporomandibular joint disorder on the habitual chewing side.

Three-dimensional quantitative evaluation of condylar bone remodeling of temporomandibular joint based on cone-beam CT imaging

Objective: To establish a three-dimensional （3D） quantitative measurement and evaluate the condylar bone remodeling of temporomandibular joint (TMJ). Methods: Pre-and post-treatment cone-beam CT (CBCT) data were obtained from 41 patients ［10 males, 31 females, mean age of (19.7±4.4) years (12-30 years old)］, who visited the Center for TMD and Orofacial Pain, Peking University School and Hospital of Stomatology from November 2014 to August 2019, and diagnosed with acute disc displacement without reduction or disc displacement with reduction, with intermittent locking and treated by manual disc reduction followed by anterior repositioning splint. First, condylar bone remodeling was evaluated according to the number of "double contour image" and qualitatively classified as no remodeling (no double contour image), partial remodeling (1-4 double contour images) and remarkable remodeling (5-6 double contour images). Then, condylar bone remodeling was quantitatively evaluated by CBCT based 3D measurement: segmenting condylar images using a semi-automatic method of the manually preliminary mark combined with watershed algorithm, reconstructing the surface models, superimposing the pre-and post-treatment condylar images and finally calculating the volumetric differences of condyle and condylar head, respectively. Results: The Kappa values of two-dimensional (2D) qualitative evaluation were 0.66-0.87, and 3D quantitative measurements of condyle and condylar head volume were also reliable, with the intraclass correlation coefficient (ICC) values of intra-observer 0.998/0.941 and inter-observer 0.999/0.942 respectively. The volumetric increment of the condyle and condylar head after treatment was (41.7±90.2) mm³ and (62.8±70.9) mm³, respectively. Eighty-two condyles were divided into three sub-groups: no remodeling (21), partial remodeling (20) and remarkable remodeling (41). Ranking of the volumetric increment of the condyle and condylar head after treatment was as follows: remarkable remodeling group>partial remodeling group>no remodeling group (P<0.05). Conclusions: The 3D quantitative measurement for evaluating condylar bone remodeling had excellent consistency and reliability, which was consistent with the qualitative classification for condylar bone remodeling. The condylar head as a region of interest was more sensitive to the volumetric changes.

The Biomechanical Effect of the Sagittal Split Ramus Osteotomy on the Temporomandibular Joint: Current Perspectives on the Remodeling Spectrum.

The sagittal split ramus osteotomy is a key approach for treating dentofacial deformities. Although it delivers excellent results, the sagittal split ramus osteotomy is believed to induce stress to the temporomandibular joint. Potential stress inducers could be classified as intra- and postoperative factors resulting in an inflammatory response and molecular cascades, which initiate physiological remodeling. Occasionally, this process exceeds its capacity and causes pathological remodeling, through either degenerative joint disease or condylar resorption. Hard evidence on how orthognathic surgery causes inflammation and how this inflammation is linked to the spectrum of remodeling remains scarce. Current concepts on this matter are mainly based on clinical observations and molecular mechanisms are extrapolated from fundamental research in other body parts or joints. This perspective study provides an overview of current knowledge on molecular pathways and biomechanical effects in temporomandibular joint remodeling. It provides research directions that could lead to acquiring fundamental evidence of the relation of orthognathic surgery and inflammation and its role in remodeling. Performing osteotomies in animal models and identifying inflammatory mediators as well as their effect on the joint seem promising. Patients affected by pathological remodeling can also provide samples for histological as well as molecular analysis. Individual susceptibility analysis by linking certain suspect phenotypes to genetic variation could identify the cause and molecular pathway responsible for degenerative joint disease and condylar resorption, ultimately leading to clinically applicable treatment and prevention strategies.

Expression of lubricin in rat posterior mandibular condylar cartilage following functional mandibular forward repositioning.

The aim of the present study was to investigate the effects of mandibular forward repositioning on expression of lubricin in rat posterior condylar cartilage. In total, fifty 5‑week-old female Sprague Dawley rats were divided randomly into experimental groups and control groups. The animals in the experimental groups were fitted with modified acrylic inclined planes to advance the mandible, whereas rats in the normal control groups were left intact. Rats were sacrificed on days3,7,14,21, and30, and temporomandibular joint (TMJ) samples were collected. The expression of lubricin of the posterior mandibular condylar cartilage was evaluated by immunohistochemistry. In the control groups, higher expression of lubricin was observed in the proliferative zone of the posterior mandibular condylar cartilage compared with the hypertrophic zone during the experimental period. Compared with the control group, the positive signals for lubricin of the posterior mandibular condylar cartilage in the experimental animals were significantly higher on days7,14, and21; however, no statistical difference was found on day3 or30. Data analyses suggest that the bite jumping appliance temporarily enhanced lubricin expression, providing agood mechanical environment for the physiologic growth of the condyle and mandible, and contributes to TMJ remodeling by the regulation of condylar chondrocyte proliferation.

Jaw biodynamic data for 24 patients with chronic unilateral temporomandibular disorder

This study assessed 24 adult patients, suffering from severe chronic unilateral pain diagnosed as temporomandibular joint (TMJ) disorder (TMD). The full dentate patients had normal occlusion and had never received an occlusal therapy, i.e., were with natural dental evolution/maturation. The following functional and dynamic factors were assessed: (1) chewing function; (2) TMJ remodeling or the condylar path (CP); and (3) lateral jaw motion or lateral guidance (LG). CPs were assessed using conventional axiography, and LG was assessed by K7 jaw tracking. Seventeen (71%) of the 24 (100%) patients consistently showed a habitual chewing side. The mean (standard deviation [SD]) of the CP angles was 47.90 (9.24) degrees. The mean (SD) of the LG angles was 42.95 (11.78) degrees. Data collection emerged from the conception of a new TMD paradigm where the affected side could be the habitual chewing side, the side with flatter lateral jaw motion or the side with an increased CP angle. These data may lead to improved diagnosis, therapy plans and evolution in TMD patients.

Adaptive remodeling of temporomandibular joint following anterior disc displacement and treatment decision making

Anterior disc displacement (ADD) of temporomandibular joint (TMJ) is one of the common oral diseases. The TMJ can be remodeled after disc displacement. The author's recent studies show that remodeled bilaminar zone is similar to the disc in composition and functions. The remodeled condyle can match the disc-like bilaminar zone. The new disc-condylar relationship can, to a certain extent, restore the function of the TMJ. Based on these studies, the author believes that the adaptive remodeling in TMJ has important guiding significance for clinical treatment and discusses the views of the treatment decision for various stages of temporomandibular disorders.

Sex differences in the estrogen-dependent regulation of temporomandibular joint remodeling in altered loading.

Temporomandibular joint (TMJ) diseases predominantly afflict women, suggesting a role of estrogen in the disease etiology. Previously, we determined that decreased occlusal loading (DOL) inhibited collagen type II (Col2) expression in the mandibular condylar cartilage (MCC) of female wild-type (WT) mice whereas no change was observed in males. This decrease in chondrogenesis was abolished by estrogen receptor beta (ERβ) deficiency in females. Therefore, the goal of this study was to examine the role of estradiol - ERβ signaling in mediating DOL effects in male mice to further decipher sex differences. Male 21 day-old WT and ERβKO male mice were treated with either placebo or estradiol and exposed to normal or DOL for 4 weeks. Cartilage thickness and cell proliferation, gene expression and immunohistochemistry of chondrogenic markers and estrogen receptor alpha (ERα), and analysis of bone histomorphometry via microCT were completed to ascertain the effect of estradiol on DOL effects to the TMJ. ERβKO male mice lack a MCC phenotype. In both genotypes, estradiol treatment increased Col2 gene expression and trabecular thickness. DOL in combination with estradiol treatment caused a significant increase in Col2 gene expression in both genotypes. The sex differences in DOL-induced inhibition of Col2 expression do not appear to be mediated by differences in estradiol levels between male and female mice. Greater understanding on the role of estrogen and altered loading are critical in order to decipher the sex dimorphism of TMJ disorders.

β2-Adrenergic signal transduction plays a detrimental role in subchondral bone loss of temporomandibular joint in osteoarthritis.

The present study tested whether activation of the sympathetic tone by aberrant joint loading elicits abnormal subchondral bone remodeling in temporomandibular joint (TMJ) osteoarthritis. Abnormal dental occlusion was created in experimental rats, which were then intraperitoneally injected by saline, propranolol or isoproterenol. The norepinephrine contents, distribution of sympathetic nerve fibers, expression of β-adrenergic receptors (β-ARs) and remodeling parameters in the condylar subchondral bone were investigated. Mesenchymal stem cells (MSCs) from condylar subchondral bones were harvested for comparison of their β-ARs, pro-osteoclastic gene expressions and pro-osteoclastic function. Increases in norepinephrine level, sympathetic nerve fiber distribution and β2-AR expression were observed in the condylar subchondral bone of experimental rats, together with subchondral bone loss and increased osteoclast activity. β-antagonist (propranolol) suppressed subchondral bone loss and osteoclast hyperfunction while β-agonist (isoproterenol) exacerbated those responses. MSCs from experimental condylar subchondral bone expressed higher levels of β2-AR and RANKL; norepinephrine stimulation further increased their RANKL expression and pro-osteoclastic function. These effects were blocked by inhibition of β2-AR or the PKA pathway. RANKL expression by MSCs decreased after propranolol administration and increased after isoproterenol administration. It is concluded that β2-AR signal-mediated subchondral bone loss in TMJ osteoarthritisis associated with increased RANKL secretion by MSCs.

Changes in the temporomandibular joint space after functional treatment of disk displacement with reduction.

This study aimed to evaluate the changes of temporomandibularjoint (TMJ) space in the treatment of disk displacement with reduction (DDWR) for class II cases. Forty-two adolescent patients with unilateral DDWR, who were successfully treated by functional appliance, were selected in this study. Magnetic resonance imaging scans were used before treatment (T1), at the start of treatment (T2), and after functional treatment (T3). Compared with the normal joint, the change of joint space index was calculated. The anterior, posterior, and superior joint spaces were analyzed on the largest sagittal plane among T1, T2, and T3. Student's t-test was used for statistical analysis. The mean treatment period was 10 months (6-16 mo). Functional appliance was effective in eliminating pain and clicking. During the phase of T1, the value of the joint space index of DDWR was significantly higher than that of the control (P < 0.05). There was a significant decrease in the anterior space and an increase in the postsuperior space at T2 (P < 0.01), and then the contrary changes occurred at T3. However, there was a significant increase in the postsuperior space and no significant decrease in the anterior space when T1 and T3 were compared. This study indicates that the TMJ space is well distributed after disk repositioning with functional treatment of DDWR. It is also suggested that the adaptive remodeling in TMJ occurs via functional treatment.

The Biology of TMJ Growth Modification

Several studies have indicated a positive response of the temporomandibular joint (TMJ) to mandibular advancement, while others have reported that TMJ adaptive responses are non-existent and negligible. Controversy continues to grow over the precise nature of skeletal changes that occur during mandibular growth modification, due to an apparent lack of tissue markers required to substantiate the precise mechanism by which this is occurring. However, evidence suggests that orthopedic forces clinically modify the growth of the mandible. To further our knowledge about the effect of orthopedic treatment on the TMJ, it is necessary that we understand the biologic basis behind the various tissues involved in the TMJ’s normal growth and maturation. The importance of this knowledge is to consider the potential association between TMJ remodeling and mandibular repositioning under orthopedic loading. Considerable histologic and biochemical research has been performed to provide basic information about the nature of skeletal growth modification in response to mandibular advancement. In this review, the relevant histochemical evidence and various theories regarding TMJ growth modification are discussed. Furthermore, different regulatory growth factors and tissue markers, which are used for cellular and molecular evaluation of the TMJ during its adaptive response to biomechanical forces, are underlined.

Sex Differences in Chondrocyte Maturation in the Mandibular Condyle from a Decreased Occlusal Loading Model

Temporomandibular joint disorders (TMDs) predominantly afflict women of childbearing age. Defects in mechanical loading-induced temporomandibular joint (TMJ) remodeling are believed to be a major etiological factor in the development of TMD. The goal of this study was to determine if there are sex differences in CD-1 and C57BL/6 mice exposed to a decreased occlusal loading TMJ remodeling model. Male and female CD-1 and C57BL/6 mice, 21days old, were each divided into two groups. They were fed either a normal pellet diet (normal loading) or a soft diet and had their incisors trimmed out of occlusion (decreased occlusal loading) for 4weeks. The mandibular condylar cartilage was evaluated by histology, and the subchondral bone was evaluated by micro-CT analysis. Gene expression from both was evaluated by real-time PCR analysis. In both strains and sexes of mice, decreased occlusal loading caused similar effects in the subchondral bone, decreases in bone volume and total volume compared with their normal loading controls. However, in both strains, decreased occlusal loading caused a significant decrease in the expression of collagen type II (Col2) and Sox9 only in female mice, but not in male mice, compared with their normal loading controls. Decreased occlusal loading causes decreased bone volume in both sexes and a decrease in early chondrocyte maturation exclusively in female mice.

Expression of chondromodulin‐1 in the temporomandibular joint condylar cartilage and disc

The temporomandibular joint (TMJ) cartilage consists of condylar cartilage and disc and undergoes continuous remodeling throughout post-natal life. To maintain the integrity of the TMJ cartilage, anti-angiogenic factors play an important role during the remodeling process. In this study, we investigated the expression of the anti-angiogenic factor, chondromodulin-1 (ChM-1), in TMJ cartilage and evaluate its potential role in TMJ remodeling. Eight TMJ specimens were collected from six 4-month-old Japanese white rabbits. Safranin-O staining was performed to determine proteoglycan content. ChM-1 expression in TMJ condylar cartilage and disc was determined by immunohistochemistry. Three human perforated disc tissue samples were collected for investigation of ChM-1 and vascular endothelial growth factor (VEGF) distribution in perforated TMJ disc. Safranin-O stained weakly in TMJ compared with tibial articular and epiphyseal cartilage. In TMJ, ChM-1 was expressed in the proliferative and hypertrophic zone of condylar cartilage and chondrocyte-like cells in the disc. No expression of ChM-1 was observed in osteoblasts and subchondral bone. ChM-1 and VEGF were both similarly expressed in perforated disc tissues. ChM-1 may play a role in the regulation of TMJ remodeling by preventing blood vessel invasion of the cartilage, thereby maintaining condylar cartilage and disc integrity.

Effect of hydrostatic pressure on ultrastructure of synovial fibroblasts from rat temporomandibular joint

To investigate the role of apoptosis in the remodeling of temporomandibular joint (TMJ) under pressure. Synovial fibroblasts obtained from rat temporomandibular joint were subjected to different hydrostatic pressure for 12 h. Changes of ultrastructure were observed by transmission electron microscope. At 30 kPa, the ultrastructure of synovial fibroblasts showed no obvious changes. At 60 kPa, the chromatin was condensated, the baryon took on crescent and the mitochondria seemed varicose. At 90 kPa, the apoptosis-like body was wrapped by membrane and embedded in the high density chromatin. Apoptosis-like change took place in ultrastructure of synovial fibroblasts under hydrostatic pressure, and the degree of the change was related to the hydrostatic pressure exerted.

Effect of estrogen replacement on temporomandibular joint remodeling in ovariectomized rats

Purpose: The investigation was performed to elucidate the effect of estrogen on the temporomandibular joint (TMJ) and to evaluate the therapeutic effect of 17β-estradiol replacement in growing rats.Materials and Methods: Thirty 4-week-old female albino Wister rats were divided into 3 groups. Ten rats were ovariectomized followed by intramuscular administration of 17β-estradiol for hormone replacement (OXV + E2), 10 were sham operated (CTL), and 10 were ovariectomized without hormone replacement (OVX). Five rats from each group were killed at 1 and 2 weeks postoperatively, and the serum estrogen was determined to verify the adequacy of replacement. The temporomandibular joints of the age-matched sham-operated control and ovariectomized groups were histomorphometrically evaluated at the same periods.Results: In OVX animals, the thickness of the articular soft tissue was increased by a concomitant increase of the transitional and cartilage zones in the anterior and posterior portions at 1 and 2 weeks postoperatively. However, the bone volume was decreased in the anterior and posterior portions at 2 weeks after the surgery and the condyle was flattened. Replacement with 17β-estradiol restored most of the histomorphometric parameters. The thickness of articular soft tissue was increased in the anterior portion by an increase in the cartilage zone in the OVX + E2 group at 2 weeks postoperatively. Increase of bone volume was found at 2 weeks after hormone replacement with a corresponding increased osteoid surface and decreased quiescent surface in the central portion at 1 week postoperatively. A flattened condyle was still noted at 2 weeks postoperatively in the OVX + E2 animals despite the hormone replacement.Conclusions: Estrogen in a physiologic concentration may play an important role in TMJ remodeling. Progesterone may be indispensable for remodeling, particularly contributing to morphogenesis.

Effect of estrogen replacement on the temporomandibular joint remodeling in ovariectomized rats

Because of the high prevalence of temporomandibular dysfunction (TMD) symptoms among women compared with men, a role for female sex hormones in the pathophysiology of TMD symptoms has been theorized. 1 Bush FM Harkins SW Harrington WG et al. Analysis of gender effect on pain perception and symptom presentation in temporomandibular pain. Pain. 1993; 53: 73 Abstract Full Text PDF PubMed Scopus (154) Google Scholar , 2 Ganshorn ML Gartner F Studies in possible correlation between diseases of the temporomandibular joint and female sex hormones. ZWR. 1975; 25: 720 Google Scholar Such a hypothesis has been further supported by reports of the presence of receptors for these hormones in the temporomandibular joint (TMJ) tissues 3 Abubaker AO John F Sotereanos GC et al. Prevalence of female sex estrogen receptors hormone use by female TMJ patients. J Dent Res. 1992; 71 (abstr): 1225 Google Scholar , 4 Milam SB Aufdemorte TB Sheridan PF et al. Sexual dimorphism in the distribution of estrogen receptors in the temporomandibular joint complex of the baboon. Oral Surg Oral Med Oral Pathol. 1987; 64: 527 Abstract Full Text PDF PubMed Scopus (85) Google Scholar , 5 Ng MC Harper RP Le C Brenden SW Effects of estrogen on the condyle cartilage as the condyle of the rat mandible in organ culture. J Oral Maxillofac Surg. 1999; 57: 818 Abstract Full Text PDF PubMed Scopus (33) Google Scholar and the finding of several epidemiologic studies that showed a high prevalence of TMD symptoms among women receiving these hormones. 6 Abubaker AO Rowhani B Laskin DM et al. Incidence of history trauma, family TMJ symptoms, and use of female sex hormones in female TMJ patients. J Dent Res. 1994; 73 (abstr): 674 Google Scholar , 7 LeResche L Saunders K Von-Kroff MR et al. Use of exogenous hormones and risk of temporomandibular disorder pain. Pain. 1997; 69: 153 Abstract Full Text Full Text PDF PubMed Scopus (279) Google Scholar Since then, several experimental studies on the effect of estrogen on the TMD tissues have been carried out. This study is very valuable in further elucidating the relationship between TMJ tissue changes and sex hormones in an experimental animal model. Such studies hopefully will advance our understanding of the role of these hormones in the pathophysiology of TMD symptoms.

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)

Influence of Function on Temporomandibular Joint Remodeling and Degenerative Disease

Influence of Function on Temporomandibular Joint Remodeling and Degenerative Disease