Quantitative cone-beam computed tomography evaluation of hard and soft tissue thicknesses in the midpalatal suture region to facilitate orthodontic mini-implant placement.

OBJECTIVE: To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sexand age-related differences in these thicknesses. METHODS: The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines. RESULTS: The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1-2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age. CONCLUSIONS: The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

Fabry disease exacerbates renal interstitial fibrosis after unilateral ureteral obstruction via impaired autophagy and enhanced apoptosis.

BACKGROUND: Fabry disease is a rare X-linked genetic lysosomal disorder caused by mutations in the GLA gene encoding alpha-galactosidase A. Despite some data showing that profibrotic and proinflammatory cytokines and oxidative stress could be involved in Fabry disease-related renal injury, the pathogenic link between metabolic derangement within cells and renal injury remains unclear. METHODS: Renal fibrosis was triggered by unilateral ureteral obstruction (UUO) in mice with Fabry disease to investigate the pathogenic mechanism leading to fibrosis in diseased kidneys. RESULTS: Compared to kidneys of wild-type mice, lamellar inclusion bodies were recognized in proximal tubules of mice with Fabry disease. Sirius red and trichrome staining revealed significantly increased fibrosis in all UUO kidneys, though it was more prominent in obstructed Fabry kidneys. Renal messenger RNA levels of inflammatory cytokines and profibrotic factors were increased in all UUO kidneys compared to sham-operated kidneys but were not significantly different between UUO control and UUO Fabry mice. Protein levels of Nox2, Nox4, NQO1, catalase, SOD1, SOD2, and Nrf2 were not significantly different between UUO control and UUO Fabry kidneys, while the protein contents of LC3-II and LC3-I and expression of Beclin1 were significantly decreased in UUO kidneys of Fabry disease mouse models compared with wild-type mice. Notably, TUNEL-positive cells were elevated in obstructed kidneys of Fabry disease mice compared to wild-type control and UUO mice. CONCLUSION: These findings suggest that impaired autophagy and enhanced apoptosis are probable mechanisms involved in enhanced renal fibrosis under the stimulus of UUO in Fabry disease.

Asymmetric nasomaxillary expansion induced by tooth-bone-borne expander producing differential craniofacial changes.

OBJECTIVES: To evaluate three-dimensional (3D) craniofacial changes induced by a non-surgical tooth-bone-borne rapid palatal expander (TBB-RPE) according to the symmetrical pattern of expansion, to investigate the 3D changes between the sides in patients with asymmetric expansion, and to identify the related factors of asymmetric expansion. SETTING AND SAMPLE POPULATION: Sixty-six patients (mean age: 19.3 ± 5.7 years) treated with TBB-RPE were divided into a symmetric expansion group (Group S, n = 46) or asymmetric expansion group (Group A, n = 20). Group S was subdivided into Group Ss (n = 27), with bilateral frontomaxillary suture (FMS) split, and Group Sn (n = 19), with no FMS split. MATERIALS AND METHODS: Pre- and post-expansion cone-beam computed tomography images were superimposed, and the common coordinated system was set. All landmarks were designated as coordinate pairs, and treatment changes were automatically calculated. Analysis of variance was conducted for intergroup comparison of craniofacial changes, and logistic regression analysis was performed to identify the related factors of asymmetric expansion. RESULTS: The frequency of asymmetric expansion was 30.3%. Group A with unilateral FMS split showed less craniofacial changes than Group Ss and more changes than Group Sn. Group A exhibited different nasomaxillary displacement between the two halves, showing greater changes in the FMS-split side. Among the tested six variables (age, gender, Angle's classification, unilateral crossbite, maxillary cant and chin deviation), chin deviation was uniquely associated with asymmetric expansion. CONCLUSIONS: Tooth-bone-borne rapid palatal expander had a risk of asymmetric expansion, especially in facial asymmetric patients with chin deviation, producing different craniofacial changes from symmetric expansion.

Novel mutations in patients with X-linked Alport syndrome: Two case reports.

RATIONALE: A genotype-phenotype correlation is known to be associated with Alport syndrome (AS). Identifying novel mutations can expand the knowledge about the natural course of AS. PATIENT CONCERNS: The first patient was a-15-year-old boy detected with proteinuria during the school health check-up. The second case was a-29-year-old woman, who visited the outpatient clinic for edema. DIAGNOSIS: We performed targeted next-generation sequencing to identify the mutations associated with AS. Results were confirmed by Sanger sequencing and multiplex ligation-dependent probe amplification. Missense mutation (c.2332G>C, p.Gly778Arg) was identified in the first case and an exon 16 deletion was also identified in the second case. INTERVENTION: We treated both cases with angiotensin receptor blocker (ARB). OUTCOMES: The amount of proteinuria in the first case did not change after ARB therapy, during the follow-up period (1 year). Proteinuria in the woman decreased to half of the baseline level, 1 year after treatment. Glomerular filtration rate was also maintained during the follow-up. CONCLUSION: We identified novel mutations in Koreans with an X-linked AS mutation in the COL4A5 gene and an individual phenotype. This is the first report of AS patients with a novel missense mutation and copy number variation.

Validation of risk prediction tools in elderly patients who initiate dialysis.

PURPOSE: The number of elderly patients with end-stage renal disease on maintenance dialysis therapy is gradually increasing. The elderly population has difficulties in making decisions regarding initiation of dialysis treatment because of their high morbidity and frailty. The purpose of this study was to determine the best prognostic tool in predicting short-term mortality in elderly patients undergoing dialysis. METHODS: This study is a multicenter retrospective study. We enrolled patients, aged ≥ 75 years, who began hemodialysis at three university hospitals in Korea from January 2010 to December 2016. We applied two comorbidity-based score tools (Thamer and Wick, each consisting of seven variables) and the Clinical Frailty Scale (CFS, seven scales), which were validated for mortality prediction in elderly incident patients. Patient's information was obtained from electronic medical records in the participating center, and mortality data (up to December 2016) were obtained from the Korean National Statistical Office. Models were compared using the area under the receiver operating characteristic curve. RESULTS: Among the 219 patients enrolled in this study, the 3- and 6-month mortality rates were 31 (14.4%) and 48 (22.4%), respectively. Receiver operating characteristic curve analysis revealed that both score systems and the CFS showed similar performance while predicting 3- and 6-month mortality. The scores from these indices correlated with survival time. CONCLUSION: Predicting short-term mortality and long-term survival time for elderly patients is possible using the Thamer and Wick scores and the CFS.

Physician Confidence in Artificial Intelligence: An Online Mobile Survey.

BACKGROUND: It is expected that artificial intelligence (AI) will be used extensively in the medical field in the future. OBJECTIVE: The purpose of this study is to investigate the awareness of AI among Korean doctors and to assess physicians' attitudes toward the medical application of AI. METHODS: We conducted an online survey composed of 11 closed-ended questions using Google Forms. The survey consisted of questions regarding the recognition of and attitudes toward AI, the development direction of AI in medicine, and the possible risks of using AI in the medical field. RESULTS: A total of 669 participants completed the survey. Only 40 (5.9%) answered that they had good familiarity with AI. However, most participants considered AI useful in the medical field (558/669, 83.4% agreement). The advantage of using AI was seen as the ability to analyze vast amounts of high-quality, clinically relevant data in real time. Respondents agreed that the area of medicine in which AI would be most useful is disease diagnosis (558/669, 83.4% agreement). One possible problem cited by the participants was that AI would not be able to assist in unexpected situations owing to inadequate information (196/669, 29.3%). Less than half of the participants(294/669, 43.9%) agreed that AI is diagnostically superior to human doctors. Only 237 (35.4%) answered that they agreed that AI could replace them in their jobs. CONCLUSIONS: This study suggests that Korean doctors and medical students have favorable attitudes toward AI in the medical field. The majority of physicians surveyed believed that AI will not replace their roles in the future.

Bariatric Surgery Reduces Elevated Urinary Mitochondrial DNA Copy Number in Patients With Obesity.

OBJECTIVE: Obesity is an independent risk factor for chronic kidney disease. Recently, urinary mitochondrial DNA (mtDNA) has been used as a surrogate marker of mitochondrial damage in various kidney diseases. However, there are no data regarding its use in patients with obesity or the change in urinary mtDNA copy number after surgery. DESIGN: We prospectively recruited age- and sex-matched healthy volunteers and patients with obesity (n = 22 in each group: nine men and 13 women). The copy number of urinary and serum mtDNA nicotinamide adenine dinucleotide dehydrogenase subunit-1 (mtND-1) and cytochrome-c oxidase 3 (mtCOX-3) was measured using quantitative PCR. We measured urinary mtDNA and body weight and carried out laboratory tests, 6 months after surgery. RESULTS: Urinary mtND-1 copy number was significantly higher in the obese group than in healthy volunteers. However, urinary mtCOX-3 and serum ND-1 copy numbers in the obese group did not differ from that in the healthy volunteers. When patients with obesity were divided into two groups, according to their baseline mtND-1 copy number, bariatric surgery reduced the mtND-1 copy number (P = 0.006) in the high baseline mtDNA copy-number group. The change in urinary mtND-1 copy number was correlated with a change in urinary albumin (r = 0.478, P = 0.025). CONCLUSIONS: Obesity is associated with elevated urinary mtND-1 copy number. Bariatric surgery reduces the elevated urinary mtND-1 copy number in patients with obesity. This suggests that bariatric surgery could attenuate mitochondrial damage in the kidney cells of patients with obesity.

Volumetric accuracy of cone-beam computed tomography.

PURPOSE: This study was performed to investigate the influence of object shape and distance from the center of the image on the volumetric accuracy of cone-beam computed tomography (CBCT) scans, according to different parameters of tube voltage and current. MATERIALS AND METHODS: Four geometric objects (cylinder, cube, pyramid, and hexagon) with predefined dimensions were fabricated. The objects consisted of Teflon-perfluoroalkoxy embedded in a hydrocolloid matrix (Dupli-Coe-Loid TM; GC America Inc., Alsip, IL, USA), encased in an acrylic resin cylinder assembly. An Alphard Vega Dental CT system (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan) was used to acquire CBCT images. OnDemand 3D (CyberMed Inc., Seoul, Korea) software was used for object segmentation and image analysis. The accuracy was expressed by the volume error (VE). The VE was calculated under 3 different exposure settings. The measured volumes of the objects were compared to the true volumes for statistical analysis. RESULTS: The mean VE ranged from -4.47% to 2.35%. There was no significant relationship between an object's shape and the VE. A significant correlation was found between the distance of the object to the center of the image and the VE. Tube voltage affected the volume measurements and the VE, but tube current did not. CONCLUSION: The evaluated CBCT device provided satisfactory volume measurements. To assess volume measurements, it might be sufficient to use serial scans with a high resolution, but a low dose. This information may provide useful guidance for assessing volume measurements.

A New Designed Expander Supported by Spike Miniscrews With Enhanced Stability.

INTRODUCTION: This article represents a new design of expander-spike expander-to correct transverse maxillary deficiency. This new type appliance is easy to fabricate, more hygienic, and less soft-tissue irritation because of elimination of acrylic plate. In addition, because of the position of mini-implant, it can provide a relatively parallel alveolar expansion, compared with other types of expander. MATERIALS AND METHODS: The spike expander consists of 2 parts: 4 spike screws and an expansion screw. Four spike screws were placed on the palatal slope. After installation of the spike screws, based on the position of spike screw, the extension arms of expansion screw were bended on the cast model, and connected to the spike screws by adding resin. The expansion screw was turned once a day (0.25 mm/d), and the process was terminated at 6 weeks. RESULTS: The stability and design of the spike screw enable widening of maxilla easier. Compared with other expander, spike expander reduces the forces being placed directly on teeth, which can maximize skeletal expansion, minimize dental tipping, produce a relatively parallel expansion, and reduce soft-tissue irritation caused by acrylic pads. Furthermore, the teeth can be aligned and leveled simultaneously using the fixed appliance because teeth are free of contact by the expander. And the best point for spike expander is that it is simply fabricated and removed. CONCLUSIONS: The design of spike expander is combining spike screws and an expansion screw, which can provide a good and easy treatment method for transverse maxillary deficiency.

Intravenous contrast media application using cone-beam computed tomography in a rabbit model.

PURPOSE: This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. MATERIALS AND METHODS: CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. RESULTS: The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. CONCLUSION: Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography.

The incidence and configuration of the bifid mandibular canal in Koreans by using cone-beam computed tomography.

PURPOSE: This study was performed to investigate the incidence and configuration of the bifid mandibular canal in a Korean population by using cone-beam computed tomography (CBCT) imaging. MATERIALS AND METHODS: CBCT images of 1933 patients (884 male and 1049 female) were evaluated using PSR-9000N and Alphard-Vega 3030 Dental CT units (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan). Image analysis was performed by using OnDemand3D software (CyberMed Inc., Seoul, Korea). The bifid mandibular canal was identified and classified into four types, namely, the forward canal, buccolingual canal, dental canal, and retromolar canal. Statistical analysis was performed by using the chi-squared test and one-way analysis of variance (ANOVA). RESULTS: Bifid mandibular canals were observed in 198 (10.2%) of 1933 patients. The most frequently observed type of bifid mandibular canal was the retromolar canal (n=104, rate: 52.5%) without any significant difference among the incidence of each age and gender. The mean diameter of the accessory canal was 1.27 mm (range: 0.27-3.29 mm) without any significant difference among the mean diameter of each type of the bifid mandibular canal. The mean length of the bifid mandibular canals was 14.97mm(range: 2.17-38.8 mm) with only a significant difference between the dental canal and the other types. CONCLUSION: The bifid mandibular canal is not uncommon in Koreans and has a prevalence of 10.2% as indicated in the present study. It is suggested that a CBCT examination be recommended for detecting a bifid canal.

Primary intraosseous squamous cell carcinoma mimicking periapical disease: a case report.

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare carcinoma, which arises within the jaws without connection to the oral mucosa and presumably develops from a remnant of odontogenic epithelium. We present a case of solid type PIOSCC in a 52-year-old male patient complaining of dull pain on his left lower molar. In this case, early stage PIOSCC mimicking a periapical lesion might lead to a one-year delay in treatment due to the misdiagnosis of osteomyelitis after extraction of the third molar. The clinical, radiological, and histologic features are described. In this case, there was initial radiographic evidence for PIOSCC mimicking a periapical lesion. Incautious radiographic interpretation and treatment procedures had delayed the correct diagnosis and resulted in extensive bony destruction during the patient's disease progression.