Assessment of Internal Fitness on Resin Crown Fabricated by Digital Light Processing 3D Printer / 치위생과학회지

BACKGROUND: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method.METHODS: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups.RESULTS: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP.CONCLUSION: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

Effects of Fast Treadmill Training on Spinal Alignment and Muscles Thickness

PURPOSE: This study examined the effects of fast walking training on a treadmill on the spinal alignment and muscle thickness of normal adults. METHODS: A total of 36 college students in their twenties participated in the study for eight weeks, and they were divided into the normal walking, fast walking, and speed change groups. All the groups were measured in a pre-test before training. The subjects performed exercise three times per week for six weeks. A post-test was conducted six weeks after training began, and a follow-up test was done two weeks after the training ended.Trunk and pelvic tilts were measured in Formetric 4D for the spinal alignment of the subjects. The muscle thickness was examined in the trunk with an ultrasound test. Repeated-measures ANOVA was conducted to test the main effects and interactions among the measurement variables according to time and group. RESULTS: ignificant differences were observed in the pelvic tilt according to time. There were significant differences in the external oblique, internal oblique, transverse abdominal muscle according to time. The post-test results showed significant differences in the left external oblique, internal oblique muscles between before training, six weeks into training, and two weeks after the completion of training. There were significant interactions in the left oblique muscles according to the time and group. CONCLUSION: These findings have some value for patient rehabilitation and clinical applications and interventions through walking training.

Effect of Kettle Bell Swing Exercise on the Body Composition and Lower Limb Muscular Activity

PURPOSE: This study examined the effect of Kettle bell swing exercise on the body composition and lower limb muscular activity. METHODS: As subjects, 26 normal adults in their twenties were divided randomly into the experiment group (n=13), in which Kettle bell exercise was applied, and the control group (n=13), in which bar exercise was applied. Both groups participated in the interventions for eight weeks with three sessions per week. Each group was assessed before training and four and eight weeks into the training to determine the effects of training intervention within and between the groups. The body composition was measured with a body composition analyzer. The changes in muscle activity were measured with a surface electromyography. An independent t-test was conducted to test the significance between the groups according to the measurement points and Repeated measured ANOVA was performed to compare the groups according to the periods with the statistical significance level set to α=0.05. RESULTS: No significant changes to the main effects of time and the interactions of time according to the measurement points were observed in the Kettle bell and control groups in the body composition (p>0.05). The muscular activity of both muscles were significantly different between the Kettle bell and control groups according to the measurement points with the exception of the right lateral gastrocnemius muscle (p<0.05). CONCLUSION: These findings suggest that Kettle bell swing exercise can have positive effects on the development of lower limb muscles.

Comparative study of postoperative stability between conventional orthognathic surgery and a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy for skeletal class III correction

OBJECTIVES: The purpose of this study is to compare the postoperative stability of conventional orthognathic surgery to a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy (BSSRO). MATERIALS AND METHODS: The study included 20 patients who underwent BSSRO for skeletal class III conventional orthognathic surgery and 20 patients who underwent a surgery-first orthognathic approach. Serial lateral cephalograms were analyzed to identify skeletal changes before surgery (T0), immediately after surgery (T1), and after surgery (T2, after 1 year or at debonding). RESULTS: The amount of relapse of the mandible in the conventional orthognathic surgery group from T1 to T2 was 2.23±0.92 mm (P<0.01) forward movement and −0.87±0.57 mm (non-significant, NS) upward movement on the basis of point B and 2.54±1.37 mm (P<0.01) forward movement and −1.18±0.79 mm (NS) upward movement on the basis of the pogonion (Pog) point. The relapse amount of the mandible in the surgery-first orthognathic approach group from T1 to T2 was 3.49±1.71 mm (P<0.01) forward movement and −1.78±0.81 mm (P<0.01) upward movement on the basis of the point B and 4.11±1.93 mm (P<0.01) forward movement and −2.40±0.98 mm (P<0.01) upward movement on the basis of the Pog. CONCLUSION: The greater horizontal and vertical relapse may appear because of counter-clockwise rotation of the mandible in surgery-first orthognathic approach. Therefore, careful planning and skeletal stability should be considered in orthognathic surgery.

Anti-cancer Activity of Anthricin through Caspase-dependent Apoptosis in Human Hypopharyngeal Squamous Carcinoma Cell

Anthricin (Deoxypodophyllotoxin), a naturally occurring flavolignan, has well known anti-cancer properties in several cancer cells, such as prostate cancer, cervical carcinoma and pancreatic cancer. However, the effects of Anthricin are currently unknown in oral cancer. We examined the anti-cancer effect and mechanism of action of Anthricin in human FaDu hypopharyngeal squamous carcinoma cells. Our data showed that Anthricin inhibits cell viability in a dose- and time-dependent manner (IC50 50 nM) in the MTT assay and Live & Dead assay. In addition, Anthricin treated FaDu cells showed marked apoptosis by DAPI stain and FACS. Furthermore, Anthricin activates anti-apoptotic factors such as caspase-3, -9 and poly (ADP-ribose) polymerase (PARP), suggesting that caspase-mediated pathways are involved in Anthricin-induced apoptosis. Anthricin treatment also leads to accumulation of the pro-apoptotic factor Bax, followed by inhibition of cell growth. Taken together, these results indicate that Anthricn-induced cell death of human FaDu hypopharyngeal squamous carcinoma cells is mediated by mitochondrial-dependent apoptotic pathway. In summary, our findings provide a framework for further exploration on Anthricin as a novel chemotherapeutic drug for human oral cancer.

Mini-plate removal in maxillofacial trauma patients during a five-year retrospective study

OBJECTIVES: The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients. MATERIALS AND METHODS: The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal. RESULTS: The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%). CONCLUSION: The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

Guided tissue regeneration using resorbable membrane with or without xenograft in osseous defect / 대한치주과학회지

PURPOSE: In advanced case of periodontitis, surgical treatment without bone contouring may result in residual pockets inaccessible to proper cleaning during post-treatment maintenance. This problem can be avoided or reduced by applying guided tissue regeneration. MATERIALS AND METHODS: All of 3 patients had deep periodontal pocket depth and bleeding on probing, and radiograph revealed osseous defect, so we planned guided tissue regeneration using resorbable membrane with or without xenograft. RESULT: 6 months later, periodontal pocket depth and bleeding on probing was improved and gingiva was stable. CONCLUSION: Guided tissue regeneration using resorbable membrane with or without xenograft in osseous defect is predictable.

The MRI Findings in the Patients of Diffuse Brain Injury: Review of the Distribution and Clinical Course

In the last decade Computed Tomography(CT) has played a critical role in the diagnostic evaluation of the patients with focal brain injury. But it is apparent from pathologic studies that CT underestimates the severity of the many forms of cerebral injury such as primary brain stem injury, non-hemorrhagic cortical contusion and diffuse axonal injury(DAI). Magnetic Resonance Imaging(MRI), however, has been shown to be highly sensitive in detecting diffuse brain injury(DBI). Among the consecutive 13 cases of DBI patients in this series for 10 months, twelve patients were verified as MR evidence of injury in prospective studies. The anatomical distribution of the injuries were 11 cases of corpus callosal lesion, 6 cases of lobar white matter lesion, 1 case of primary brain stem lesion. The sensitivities of MR imaging in detecting the primary lesion were 76.9%(10/13) in T1WI and 92.3%(12/13) in T2WI. In DBI, patients with callosal injuries had higher incidence(8/12) than lobar white matter and primary brain stem lesion, the corpus callosal atrophy by midsaggital MR imaging and behavioral seguellae in survivous of severe head injury implicate the corpus callosal injury and degeneration. More accurate detection and delineation of traumatic lesions with MR should permit more accurate prediction of neurologic and cognitive recovery and assist in optimizing form of treatment.