• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.270-274
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• 2010

Introduction: Limited mouth opening is a representative clinical symptom of temporomandibular disorders (TMD) with anterior disc displacement without reduction (ADDWOR). Various treatment methods have been proposed for patients with ADDWOR. This study examined the clinical effectiveness of template therapy for patients with mouth opening difficulty due to the ADDWOR. Material and Methods: A total of 14 patients (female 12, male 2, average age: $29.1{\pm}14.4$), who had been treated in the template clinic, Sooncheonhyang University Bucheon Hospital, from January of 2006 to December of 2008, were enrolled in this study. The subjects were selected according to the following criteria: more than 2 weeks after the onset of locking, mouth opening range <35 mm, and confirmed ADDWOR without a synovial pathology by magnetic resonance imaging (MRI). All patients were treated with the template appliance, instructed to wear it while sleeping and exercise for at least 10 hours per day. The maximum mouth opening (MMO) range and pain recognition scores before and after template therapy were recorded and compared. A paired t-test and Wilcoxon's signed rank test were used for statistical analysis. Results: After the periodical follow up, significant improvement in the opening range was observed in the template treatment group. The average MMO range before treatment was $30.2{\pm}3.5mm$ and the average MMO after treatment and follow up was $47.1{\pm}4.7mm$. The mean amount of mouth opening increment was $16.9{\pm}5.4mm$ (P<0.01) and the pain recognition scores before and after treatment was also improved.(P=0.001) Conclusion: The template appliance proved to be efficient for the treatment of TMD with a closed lock and painful joint due to ADDWOR.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.293-303
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• 2007

The purpose of this paper is to evaluate if there is a relationship between anterior disc displacement without reduction and development of anterior open bite, and a relation between occurrence of open bite and occlusal appliance therapy. In general, the statistically significant differences were found between the Group 1 and 2 and normal mean group. The variables that represent mandibular size and form, showed a statistical significance in all 3 groups. Also 3 groups patients had a smaller ANB, a larger FMA than normal mean group. When we compared the 3 groups with respect to all cephalometric measurements by One-way analysis of variance (ANOVA), group 1 and 2 patients had a larger FMA, a larger SN to mandibular plane angle, a larger maxillomandibular plane angle, a larger occlusal plane to mandibular plane angle, a smaller total posterior facial height/total anterior facial height(%), and a larger gonial angle than group 3. The statistically significant differences were not found between the Group 1 and 2, and skeletal patterns were similar. Thus, morphologic features of patients with vertical discrepancies may represent a risk factor for the development of anterior open bite with or without occlusal appliance treatment. In case of patients with vertical discrepancy, we may have to be more careful when inducing a change of the vertical dimension.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.337-349
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• 1999

The extracellular matrix(ECM) is a complex network of different combination of collagens, glycosaminoglycans, laminin, fibronectin, and many other glycoproteins including proteolytic enzymes. The composition and organization of the ECM contributes to the uniques physical or biomechanical properties of a tissue. Fibronectins(FN) are dimeric glycoproteins located on cell surfaces, in the matrix of connective tissue, and in blood. Fibronectins mediate cell attachment to collagen substratum and have been implicated in a variety of important biological processes, including embryogenesis and cell differentiation. The purpose of this study was to determine the effects of surgical induction of anterior disk displacement(ADD) on distribution of fibronectin in the rabbit temporomandibular joint(TMJ) tissues included the articular cartilage, disc, retrodiscal tissue, articular eminence using an immunohistochemical technique. The left TMJ was exposed surgically, and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The right TMJ served as a shamoperated control. Normal joints were used as a nonoperated control. Fourty-five rabbits were used for experiments in total. For fibronectin immunohistochemical study, eighteen rabbits (one normal group and 5 experimental groups, each group consists of 3 rabbits) were used. The experimental rabbits were sacrified after operation period of 2, 3, 4, 6 and 8 weeks on fibronectin. The obtained results were as follows ; 1. Fibronectin immunoreaction on all TMJ tissues(mandibular condyle, articular disc, retrodiscal tissue, articular eminence) in the normal rabbit was observed. Especially the reverse cell layer and proliferation zone of articular cartilage of condyle show strong positive reaction. 2. Depletion of fibronectin in the all TMJ tissues except hypertrophic zone of articular cartilage occurred at 2 weeks following induction of ADD. 3. The restoration of immunoreaction at 4 weeks was observed and a progressive increasing reaction at 6 weeks, 8 weeks also was found. Our study generally showed degenerative changes in TMJ tissues after ADD although TMJ tissues adapted or degenerated to abnormal loads and stress distribution according to the remodeling capacity of TMJ tissues.

• The korean journal of orthodontics
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• v.51 no.2
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• pp.105-114
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• 2021

Objective: The purpose of this study was to evaluate the relationship between rotational disk displacement (DD) of the temporomandibular joint (TMJ) and the dentoskeletal morphology. Methods: Women aged > 17 years were included in this study. Each subject had a primary complaint of malocclusion and underwent routine cephalometric examinations. They were divided into five groups according to the findings on sagittal and coronal magnetic resonance images of their TMJs: bilateral normal disk position, bilateral anterior DD with reduction (ADDR), bilateral rotational DD with reduction (RDDR), bilateral anterior DD without reduction (ADDNR), and bilateral rotational DD without reduction (RDDNR). Twenty-three cephalometric variables were analyzed, and the Kruskal-Wallis test was used to evaluate differences in the dentoskeletal morphology among the five groups. Results: Patients with TMJ DD exhibited a hyperdivergent pattern with a retrognathic mandible, unlike those with a normal disk position. These specific skeletal characteristics were more severe in patients exhibiting DD without reduction than in those with reduction, regardless of the presence of rotational DD. Rotational DD significantly influenced horizontal and vertical skeletal patterns only in the stage of DD with reduction, and the mandible exhibited a more backward position and rotation in patients with RDDR than in those with ADDR. However, there were no significant dentoskeletal differences between ADDNR and RDDNR. Conclusions: The results of this study suggest that rotational DD of TMJ plays an important role in the dentoskeletal morphology, particularly in patients showing DD with reduction.

• Korean Journal of Radiology
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• v.23 no.2
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• pp.218-225
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• 2022

Objective: This study aimed to explore the feasibility of functional evaluation of the lateral pterygoid muscle (LPM) using diffusion tensor imaging (DTI) in patients with temporomandibular joint disorders (TMDs). Materials and Methods: A total of 119 patients with TMD (23 male and 96 female; mean age ± standard deviation, 41 ± 15 years; 58 bilateral and 61 unilateral involvements for a total of 177 joints) and 20 healthy volunteers (9 male and 11 female; 40 ± 13 years; 40 joints) were included in this prospective study. Based on DTI of the jaw in the resting state, the diffusion parameters, apparent diffusion coefficient (ADC), fractional anisotropy (FA), λ1, λ2, and λ3 of the superior and inferior heads of the LPM (SHLPM and IHLPM) were measured. Patients with TMD with normal disc position (ND), anterior disc displacement with reduction (ADWR), and anterior disc displacement without reduction (ADWOR) were compared. Results: Patients with TMD overall, and ADWR and ADWOR subgroups had significantly higher ADC, λ1, λ2, and λ3 in both the SHLPM and IHLPM than those in volunteers (p < 0.05 for all), whereas the ND subgroup only had significantly higher ADC and λ1 (p < 0.001). Meanwhile, significant differences in FA in the SHLPM and IHLPM were found between volunteers and ADWOR (p = 0.014 and p = 0.037, respectively). Among the three TMD subgroups, except for λ3 and FA in the ADWR subgroup, ADWR and ADWOR subgroups had significantly higher ADC, λ1, λ2, and λ3 and lower FA than those in the ND group (p < 0.050). There was no significant difference in diffusion variables between ADWR and ADWOR. In ADWOR, the osteoarthritis group had significantly higher λ3 and lower FA values in the IHLPM than those in the non-osteoarthritis group. Conclusion: DTI successfully detected functional changes in the LPM in patients with TMD. The unsynchronized diffusivity changes in the LPM in different subgroups of TMD signified the possibility of using diffusion parameters as indicators to identify the severity of LPM hyperfunction at various stages of TMD.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.44.1-44.7
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• 2019

Background: We evaluated the improvement of pain and the increase in mouth opening after temporomandibular joint arthrocentesis and the possible association with various factors such as previous splint treatment, medication, and diagnosis. Results: We studied 57 temporomandibular joint disorder patients who underwent arthrocentesis at Korea University Anam Hospital. These patients (24 males and 33 females, aged between 15 and 76 years) underwent arthrocentesis that was performed by one surgeon. The degree of mouth opening (assessed using the maximum mouth opening: MMO) and pain (assessed using the visual analog scale: VAS) were assessed pre- and post-arthrocentesis. The study also investigated whether treatment modalities other than arthrocentesis (medication and appliance therapy) were performed. Statistical analysis revealed that there was a significant difference in mouth opening and pain after temporomandibular joint arthrocentesis. Preoperative appliance therapy affected the results of arthrocentesis, but it was not statistically significant. With regard to pain relief, preoperative diagnosis did not show a significant difference. However, with regard to maximum mouth opening, patients with disc displacement without reduction with limited mouth opening (closed lock) showed the highest recovery (11.13 mm). Conclusion: The average of MMO increase after arthrocentesis was 9.10 mm, and patients with disc displacement without reduction with locking (closed lock) showed most recovery in maximum mouth opening and it was statistically significant. The average pain relief of patients after arthrocentesis was 3.03 in the VAS scale, and patients using anterior repositioning splint (ARS) preoperatively showed the most pain relief.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.423-427
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• 2001

Objective: This study was prepared to figure out a certain dimension and morphology of the condyle at the central, medial and lateral aspects on MR images of asymptomatic volunteers, which could be comparable with those of the TMD patients' condyle. Materials: Sixty TMJs from 30 asymptomatic volunteers(15 male, 15 female) who had no clinical symptoms and no disc displacement on sagital and coronal view of MRI were served as normal. Method: MR images were taken from the asymptomatic volunteers and the dimension of the anteroposterior length, mediolateral width, height, convexities were measured through the images on the sagittal and coronal sections of mandibular condyle. Then, these data were collected and analyzed. Result: The mean value of anteroposterior length was $8.00{\pm}1.21mm$ at central section and mediolateral length was $21.40{\pm}2.32mm$ on coronal view. The anterior condylar length at medial side was the shortest and the convexity of anterior slop at the lateral side was proved to be the flattest among 3 sections. There were little dimensional and morphological differences at sagittal sections, but the mediolateral width of condyle at coronal section was significantly different between male and female. Conclusion: In sagittal sections, the anterior condyle length was shortest at medial side and the convexity of anterior slop was flattest at lateral side, and there were little dimensional and morphologic differences between male and female. In coronal section, male's condyle was more wider and flatter than female's.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.3
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• pp.178-181
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• 2022

Williams-Beuren syndrome (WS) is a rare genetic disorder that results from microdeletion at chromosome 7, which harbors the elastin gene. Clinical findings include arteriopathy, aortic stenosis, hypertension, and laxities and contractures in different joints throughout the body. While many components of the temporomandibular joint (TMJ) normally contain elastin, there are few reports on TMJ manifestations of WS. This study reports a TMJ ankylosis case in a WS patient and shares insight on a possible link between development of TMJ ankylosis and elastin deficiency in WS patients. A WS patient presented with bilateral TMJ ankylosis and was successfully treated with TMJ gap arthroplasty. Hypermobility of TMJ and lack of elastin in retrodiscal tissue can induce anterior disc displacement without reduction. Due to lack of elastin, which has a significant role in the compensatory and reparatory mechanism of TMJ, WS patients might be prone to TMJ ankylosis.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.191-203
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• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• Asian Spine Journal
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• v.12 no.6
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• pp.1060-1068
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• 2018

Study Design: Retrospective study. Purpose: Lumbar intervertebral disc degeneration is an important cause of low back pain. Overview of Literature: Spinal fusion is often reported to have a good course for adolescent idiopathic scoliosis (AIS). However, many studies have reported that adjacent segment degeneration is accelerated after lumbar spinal fusion. Radiography is a simple method used to evaluate the orientation of the vertebral column. magnetic resonance imaging (MRI) is the method most often used to specifically evaluate intervertebral disc degeneration. The Pfirrmann classification is a well-known method used to evaluate degenerative lumbar disease. After spinal fusion, an increase in stress, excess mobility, increased intra-disc pressure, and posterior displacement of the axis of motion have been observed in the adjacent segments. Methods: we retrospectively secured and analyzed the data of 15 patients (four boys and 11 girls) with AIS who underwent a spinal fusion surgery. We studied the full-length view of the spine (anterior-posterior and lateral) from the X-ray and MRI obtained from all patients before surgery. Postoperatively, another full-length spine X-ray and lumbosacral MRI were obtained from all participants. Then, pelvic tilt, sacral slope, curve correction, and fused and free segments before and after surgery were calculated based on X-ray studies. MRI images were used to estimate the degree to which intervertebral discs were degenerated using Pfirrmann grading system. Pfirrmann grade before and after surgery were compared with Wilcoxon signed rank test. While analyzing the contribution of potential risk factors for the post-spinal fusion Pfirrmann grade of disc degeneration, we used generalized linear models with robust standard error estimates to account for intraclass correlation that may have been present between discs of the same patient. Results: The mean age of the participant was 14 years, and the mean curvature before and after surgery were 67.8 and 23.8, respectively (p<0.05). During the median follow-up of 5 years, the mean degree of the disc degeneration significantly increased in all patients after surgery (p<0.05) with a Pfirrmann grade of 1 and 2.8 in the L2-L3 before and after surgery, respectively. The corresponding figures at L3-L4, L4-L5, and L5-S1 levels were 1.28 and 2.43, 1.07 and 2.35, and 1 and 2.33, respectively. The lower was the number of free discs below the fusion level, the higher was the Pfirrmann grade of degeneration (p<0.001). Conversely, the higher was the number of the discs fused together, the higher was the Pfirrmann grade. Conclusions: we observed that the disc degeneration aggravated after spinal fusion for scoliosis. While the degree of degeneration as measured by Pfirrmann grade was directly correlated by the number of fused segments, it was negatively correlated with the number of discs that remained free below the lowermost level of the fusion.