• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.265-274
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• 2006

Temporomandibular joint (TMJ) internal derangement, especially disc displacement with reduction (DDwR) is the most common TMJ arthropathy and has been thought to do some effects on masticatory performance. Measuring of maximal bite force has been widely used as objective and quantitative method of evaluating masticatory performance, but previous studies showed various results due to various characteristics of subjects and different measuring devices and techniques. In a few studies about the correlation of bite force and temporomandibular disorders (TMD), some authors reported that bite force and masticatory performance would be reduced in patients with TMD because of pain. But the correlation of changes in structure of articular disc and masticatory performance has not been well investigated yet. In this study, to investigate the influences of non-painful disc change on the masticatory performance, we measured the value of maximal bite force, occlusal contact area and occlusal pressure of 39 patients with non-painful DDwR of the TMJ using pressure sensitive film, and compared it with that of 59 controls. The results are summarized as follows: 1. The maximal bite force (P<0.01) and the occlusal contact area (P < 0.05) of the DDwR patients were greater than the controls. 2. There was no significant difference in occlusal pressure between the DDwR patients and the controls (P > 0.05). 3. The maximal bite force of the male group was greater than that of the female group (P < 0.05). However, the occlusal contact area and the occlusal pressure between the male and the female group didn't show significant difference (P > 0.05). From the results above, we can suggest that DDwR could be a factor of changing bite force, but more controlled, large scaled and EMG related further study is needed.

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.391-397
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• 2021

Purpose: Tranexamic acid (TXA) can reduce perioperative blood loss and the frequency of blood transfusions in lower extremity surgery. On the other hand, the effects of TXA on reverse total shoulder arthroplasty (rTSA) remain undetermined. This study evaluated the efficacy of TXA on perioperative blood loss, transfusion requirements, and the change in the hemotologic index. Materials and Methods: This study evaluated patients who underwent rTSA from September 2009 to July 2020. The patients were classified into two groups. The TXA group were administered TXA intravenously and topical TXA during surgery. The non-TXA group was not administered TXA. The quantity of hemovac drainage, which represented the postoperative blood loss, transfusion requirements, and postoperative change in hemoglobin and hematocrit level, were recorded. Results: The TXA and non-TXA groups consisted of 93 and 84 patients, respectively. The preoperative demographics showed no significant differences in age (72.0±7.0 vs. 71.5±5.8, p=0.656), sex (male:female, 28:65 vs. 23:61, p=0.689) and the prevalence of hypertension and diabetes (hypertension:diabetes:both, 36:3:13 vs. 32:3:8, p=0.806) between the two groups. There were significant differences in the requirements of transfusion (0 vs. 9, p=0.001), hemovac drainage at the 1^st (98.8±61.2 ml vs. 162.7±98.8 ml, p<0.001), the 2^nd postoperative day (73.8±48.4 ml vs. 91.5±54.5 ml, p=0.024), hemoglobin level at the 1^st (11.7±1.2 g/dl vs. 11.2±1.4 g/dl, p=0.048), 3^rd (10.9±1.2 g/dl vs. 10.2±1.2 g/dl, p<0.001), and 6^th (11.2±1.3 g/dl vs. 10.7±1.3 g/dl, p=0.020) postoperative day, and the hematocrit level at the 1^st (35.0%±3.6% vs. 32.5%±3.8%, p=0.001), 3^rd (32.3%±5.0% vs. 29.8%±3.6%, p<0.001), and 6^th (33.5%±3.8% vs. 31.5%±3.7%, p<0.001) postoperative day between the two groups. Conclusion: Intravenous and topical intra-articular TXA can reduce the transfusion requirement and blood loss in rTSA.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.418-426
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• 2019

Purpose: This study analyzed the features of humeral head decentralization in large to massive rotator cuff tears with a shoulder dislocation in the elderly. Moreover, shoulder instability and treatment were reviewed. Materials and Methods: From May 2005 to February 2017, Group A containing 45 cases (45 patients) over 65 years old accompanied by a large or massive rotator cuff tear with a shoulder dislocation and Group B containing 45 cases (45 patients) without a shoulder dislocation were enrolled. The mean ages in Groups A and B were 73.2 and 72.1 years old, and the mean follow-up periods were 30.7 and 31.3 months, respectively. Twenty-one cases (46.7%) in Group A underwent rotator cuff repair, and 8 cases (17.8%) underwent concomitant rotator cuff repair with Bankart repair. Sixteen cases (35.6%) underwent reverse total shoulder arthroplasty for cuff tear arthropathy. 45 cases (100%) in Group B underwent rotator cuff repair. The off-the center and head elevation were measured in the preoperative magnetic resonance imaging (MRI) of Groups A and B. The preoperative and postoperative visual analogue scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and University of California Los Angeles (UCLA) score in Groups A and B were compared. Results: In Groups A and B, the mean off-the centers were posterior 7.41 mm and posterior 2.02 mm (p=0.03), and the mean head elevations were superior 6.66 mm and superior 2.44 mm (p=0.02), respectively. The mean ASES scores of Groups A and B were 32.8 and 33.4 before surgery, and 77.1 (p=0.02) and 78.1 (p=0.02) after surgery (p=0.18), respectively. The mean UCLA scores of Groups A and B were 13.1 and 12.8 before surgery, and 28.9 (p=0.02) and 29.5 (p=0.01) after surgery (p=0.15), respectively. Conclusion: Patients over 65 years old with a shoulder dislocation in large to massive rotator cuff tears had higher off-the center and head elevation on the preoperative MRI than those without a shoulder dislocation. This measurement can help predict preceding shoulder instability. Early rotator cuff repairs should be performed and other treatments, such as Bankart repair and reverse total shoulder arthroplasty, should also be considered.