• Journal of Oral Medicine and Pain
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• v.41 no.2
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• pp.41-47
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• 2016

Purpose: The purpose of this study was to analyze the size and morphology of mandibular condyle and mandibular fossa between temporomandibular joint (TMJ) disc displacement (DD) patients and healthy subjects using cone-beam computed tomography (CBCT). Methods: Twenty healthy subjects and twenty TMJ DD patients participated in this study respectively. We made five measurements in mandibular condyle (medio-lateral dimension, antero-posterior dimension, condyle height, intercondylar distance and intercondylar angle) and two measurements in mandibular fossa (mandibular fossa depth and articular eminence angle) using CBCT image. Results: There was no difference between two groups in medio-lateral dimension. In case of antero-posterior dimension, average of healthy controls was larger than that of TMJ DD patients, but that was not significant statistically. There were no significant differences between two groups in condyle height. Comparing intercondylar distance and intercondylar angle between two groups, there was no significant difference between two groups. In comparison of mandibular fossa depth and articular eminence angle, there was no significant difference between two groups. Conclusions: We couldn't find any definite relationship between TMJ morphology and TMJ DD.

• Journal of Oral Medicine and Pain
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• v.16 no.1
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• pp.33-72
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• 1991

The purpose of this study was to investigate the stress distribution and the displacement in the temporomandibular joints following the teeth loss patterns. The three dimensional finite element method was used for a mathematical model. The finite element model was composed of 1,632 elements and 2,411 nodes in the mandible with articular disc and mandibular fossa of the temporal bone. The masseter, the temporal and the internal pterygoid muscle forces were applied at each insertion site, bisecting point of gonion and antegonion, tip of the coronoid process, and gonion at the ration of 2:2:1 respectively. The directions of muscles force were obtained from frontal and lateral cephalometric tracings using bony landmarks of the skull. The results were as follows : 1. In control model, the minimum principal stresses were concentrated on the region of anterosuperior part of the condyle head and articular disc, and maximum principal stresses on the anterior part of the condyle head and posterolateral part of the articular disc. 2. In case of unilateral teeth loss, the greater principal stress appeared at the teeth loss side and the principal stresses increased at the teeth loss side as the number of the posterior teeth loss went up. 3. In case of bilateral teeth loss, the principal stresses were greater than those of the control model and as the number of the posterior teeth loss increased, the grater principal stresses on the temporomandibular joints appeared at the both side. 4. When the posterior teeth existed bilateral, the principal stress patterns were similar to those of the control model. 5. The displacement ws directed mainly upward and backward in the upper part of the temporomandibular joints and upward and forward in the largest part of the condyle head. The displacement increased as the number of the posterior teeth loss went up.

• The Journal of the Korean dental association
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• v.51 no.6
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• pp.302-312
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• 2013

It has been established that disk displacement of the temporomandibular joint(TMJ) can cause mandibular asymmetry in growing subjects. One of the causes of internal derangement of TMJ seems to be the result of poor positioning of the joint structure in unilateral cross bite, and the subsequent occlusal trauma transferred to the functioning unit of the mandible, the joint and disc. Transverse discrepancy of the maxillary and the mandibular posterior dentoalveolar units was often found in mandibular asymmetric subjects. Most of the asymmetry in growing subjects becomes worse with further growth if left untreated. However once sufficient posterior overjet is gained through orthodontic treatment, many cases have shown improvement in facial asymmetry. Furthermore, the position of condyles in computed tomogram(con-beam CT) changed from anatomically unfavorable position to more concentric position.

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.205-211
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• 2012

A 35 year-old female presented with the complaint of sudden occurrence of bite change and concurrent opening limitation, as well as pain in the right temporomandibular joint (TMJ) during mouth opening. From her history it was revealed that she had simple clicking of right TMJ for several years before onset of these symptoms, and that the clicking sound subsided recently after development of opening limitation. On clinical examination, anterior open bite, midline shift of the mandible to right, and premature contacts on left posterior teeth were observed. Maximum mouth opening and lateral movement to left were also restricted. On magnetic resonance images, the right TMJ showed anterior disc displacement without reduction and the posterior joint space is greatly collapsed by retrusion of the condyle. It was thought that the sudden occurrence of occlusal change would be resulted from abrupt displacement of the mandible associated with development of the anterior disc displacement without reduction. The stabilization appliance traction therapy was performed initially for first 3 months along with physical and pharmacologic therapy. However, the anterior open bite and opening limitation didn't resolve and the position of mandible still remained altered. So the stabilization appliance was changed to intermaxillary traction device. Then the mandible returned progressively to normal position and the occlusion became more stable and comfortable. After 5 months of intermaxillary traction therapy, the anterior open bite was dissolved completely and the occlusion became stabilized satisfactorily along with recovery of normal mouth opening range. On post-treatment magnetic resonance image, remodeling of condylar head was observed.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.2
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• pp.75-84
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• 2001

The purpose of this study is to to analyze the mechanical stress on articular disk of the dentated skull with the condition of unilateral posterior molar missing. For this study, the three dimensional finite element model of human skull scanned by means of computed tomography. (G.E. 8800 Quick, USA) was constructed. The finite element model of jaws is composed of 98,394 elements and 38,321 nodes, and it consists of articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. Boundary condition included rigid restraints at the first molar and endosteal cortical surfaces of the insertion points of temporal bone. The data derived from Nelson's study were used for the loading conditions of mandible during clenchings and for maxilla, new loading and constraint conditions were applied. A clenching task during intercuspal position was modeled to the three dimensional finite element model. The stress level and displacement of articualr disc on the model with unilateral posterior molar missing under bilateral clenching task can be analyzed. During bilateral clenchings, the compressive stress level and diplacement of the articular disk on the side of unilateral posterior molar missing is greater than that on the case with full dentition, whereas a higher stress was found on the disk on the balancing side of the full dentition. Although this kind of study is not enough to explain the role of occlusion as an etiologic factor of TMD, there may be a possibiliy that the condition of posterior molar missings may contribute in part to the TMJ biomechanics.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.9-14
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• 2011

Purpose: The pelvic tilting exercise is a well recognized rehabilitation maneuver. However, little information is available on the changes of lumbar segmental motion during pelvic tilting. This study was conducted to measure the kinematics of the pelvic tilting exercise on the supine and prone positions via fluoroscopy. Methods: A total of 10 female subjects were enrolled. During anterior, neutral, and posterior pelvic tilting, radiographs were taken in each exercise via fluoroscopy (ARCADIS Orbic, Siemens, USA). Images were sent to the picture archiving communication system (PACS), and the digitized images were analyzed using LabVIEW software (National Instruments, USA). Lumbosacral lordosis and the intervertebral body angle, intervertebral disc angle, and intervertebral displacement were analyzed. Results: The results of lumbar kinematic analysis during three tilting postures in the supine and prone positions demonstrated that lumbosacral lordosis and the intervertebral body angle and intervertebral disc angle were significantly higher when the pelvis was tilted anteriorly (p>0.05). However, there was no significant difference between anterior and neutral tilting in the intervertebral disc angle at the L3/4 level in the prone position (p>0.05), and there was no significant difference among tilting positions in intervertebral body displacement in the prone position (p>0.05). Conclusion: This study provides scientific evidence about the pelvic tilting exercise in lumbosacral segmental motion. Depending on the pelvic tilting exercise, kinematic changes were demonstrated in both positions, especially in the supine position. It is suggested that the supine position is effective for mobility, but it should be used carefully for the LBP (Low back pain) patient with hypermobility.

• The Korean Journal of Pain
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• v.25 no.2
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• pp.116-120
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• 2012

A psoas compartment block has been used to provide anesthesia for orthopedic surgical procedures and analgesia for post-operative pain. Currently, this block is advocated for relieving pain in the lower extremity and pelvic area resulting from various origins. We report a case of a 69-year-old male patient who had gait abnormality with posterior pelvic and hip pain, which were both aggravated by hip extension. From the magnetic resonance image, the patient was found to have a laterally herniated intervertebral disc at the L2/3 level, which compressed the right psoas muscle. This was thought to be the origin of the pain, so a psoas compartment block was performed using 0.25% chirocaine with triamcinolone 5mg, and the pain in both the pelvis and hip were relieved.

• The Korean Journal of Pain
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• v.25 no.4
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• pp.258-261
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• 2012

Posterior neck pain is a common complaint of patients in the pain clinic. The atlas (C1) burst fracture is known to be a cause of posterior neck pain and instability. Although the atlas burst fracture and instability can be discovered by plain X-rays which show lateral mass displacement or widening of the atlantodental interval, assessment of an atlas burst fracture can be difficult if there is no instability in the imaging study. Here we report a case of a 46-year-old female patient who had complained of sustained posterior neck pain for 6 months. Plain X-rays showed only disc space narrowing at C4/5 and C5/6, without any cervical instability. However, an unrecognized C1 lateral mass fracture was detected by CT and MRI. The patient's pain was then successfully treated after atlantoaxial joint injection with a C2 DRG block.

• 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.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.397-409
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• 2007

Owing to needs of biomechanical comprehension and analysis to obtain various medical treatment designs which are related with the spine in order to cure and diagnose LBP patients, the FE modeling and nonlinear analysis of lumbosacrum including a partial ilium and iliolumbar ligaments, were carried out. First, we investigated whether the geometrical configuration of vertebrae displayed by DICOM slice files is regular and normal condition. After constructing spinal vertebrae including a partial ilium, a sacrum and five lumbars (from L1 to L5)with anatomical shape reconstructed using softwares such as image modeler and CAD modeler, we added iliolumbar ligaments, lumbar ligaments, discs and facet joints, etc.. And also, we assigned material property and discretized the model using proper finite element types, thus it was completely modeled through the above procedure. For the verification of each segment, average sagittal ROM, average coronal ROM and average transversal ROM under various loading conditions(${\pm}10Nm$), average vertical displacement under compression(400N), ALL(Anterior Longitudinal Ligament) and PLL(Posterior Longitudinal Ligament) force at L12 level, strains of seven ligaments on sagittal plane at L45 level and maximal strain of disc fibers according to various loading conditions at L45 level, etc., they were compared with experimental results. For the verification of multilevel-lumbosacrum spine including partial ilium and iliolumbar ligaments, the cases with and without iliolumbar ligaments were compared with ROM of experiment. The results were obtained from analysis of the verified FE model as follows: I) Iliolumbar ligaments played a stabilizing role as mainly posterior iliolumbar ligaments under flexion and as both posterior and anterior iliolumbar ligaments of one side under lateral bending. 2) The iliolumbar ligaments decreased total ROM of 1-8% in total model according to various motion conditions, which changed facet contact forces of L5S level by approximately 0.8-1.4 times and disc forces of L5S level by approximately 0.8-1.5 times more than casewithout ilioligaments, under various loading conditions. 3) The force of lower discs such as L45 and L5S was bigger than upper discs under flexion, left and right bending and left and right twisting, except extension. 4) It was predicted that strains of posterior ligaments among iliolumbar ligaments would produce the maximum 16% under flexion and the maximum 10% under twisting. 5) It's expected that this present model applies to the development and design of artificial disc, since it was comparatively in agreement with the experimental datum.