OBJECTIVE: This study was conducted to perform histomorphometric evaluations of the bone surrounding orthodontic miniscrews according to their proximity to the adjacent tooth roots in the posterior mandible of beagle dogs. METHODS: Four male beagle dogs were used for this study. Six orthodontic miniscrews were placed in the interradicular spaces in the posterior mandible of each dog (n = 24). The implanted miniscrews were classified into no loading, immediate loading, and delayed loading groups according to the loading time. At 6 weeks after screw placement, the animals were sacrificed, and tissue blocks including the miniscrews were harvested for histological examinations. After analysis of the histological sections, the miniscrews were categorized into three additional groups according to the root proximity: high root proximity, low root proximity, and safe distance groups. Differences in the bone–implant contact (BIC, %) among the root proximity groups and loading time groups were determined using statistical analyses. RESULTS: No BIC was observed within the bundle bone invaded by the miniscrew threads. Narrowing of the periodontal ligament space was observed in cases where the miniscrew threads touched the bundle bone. BIC (%) was significantly lower in the high root proximity group than in the low root proximity and safe distance groups. However, BIC (%) showed no significant differences among the loading time groups. CONCLUSIONS: Regardless of the loading time, the stability of an orthodontic miniscrew is decreased if it is in contact with the bundle bone as well as the adjacent tooth root.
Animals ; Dogs ; Humans ; Male ; Mandible ; Periodontal Ligament ; Tooth Root

Purpose: To investigate the outcomes of patients who underwent surgical correction of congenital superior oblique muscle paralysis in adulthood. Methods: We retrospectively analyzed the medical records of 35 patients who underwent surgical correction of congenital superior oblique muscle paralysis after the age of 18 years. At the final follow-up, success was defined as residual hypertropia < 4 prism diopters (PD), whereas failure was defined as residual hypertropia ≥ 5 PD or overcorrection. Clinical features were compared between the success and failure groups to identify factors affecting the surgical outcome. At the final follow-up, the resolution of symptoms, such as head tilt and diplopia, was also recorded. Results: Of the 35 patients, 24 (68.6%) and 11 (31.4%) were classified into the success and failure groups, respectively. Preoperative vertical deviation was larger in the failure group compared to the success group (23.1 vs. 15.2 PD, respectively; p < 0.05). Of the 31 patients with preoperative head tilt, head tilt resolved in 29 (93.5%). Of the 19 patients with diplopia, it resolved in all except 1 who was overcorrected. Conclusions The preoperative vertical angle of the superior oblique muscle may affect the outcome of surgery performed in adulthood for correcting congenital superior oblique paralysis. Head tilt, diplopia, and subjective symptoms are typically resolved postoperatively.

MRI (magnetic resonance imaging ) had been the most up-to-dated modality in evaluating white matter disease in recent years, whereas US (ultrasonogram) has been used extensively in diagnosis of neonatal PVL(periventricular leukomalacia) conventionally. We evaluated the diagnostic value of MRI by reviewing the MR findings and correlation of MR and US of PVL in II preterm infants. Evaluation criteria were MR signal intensity and discrimination of PVL on each pulse sequences land comparision between MR and US findings performed simultaneously, on the extent of PVL, size of the largest cyst and detectability of hemorrhagic lesion. MR findings of 11 cases of PVL were of low signal patterns on T1WI (T1weighted image) in 7, low signal patterns of PDWI (proton density weighted image) in 9, iso signal patterns on T2WI(T2weighted image) in 8 and low signal patterns on STIR(short time inversion recovery) in 7 cases. The lesions of 11 PVL were well discriminated in all 11 cases of T1WI, 7 cases of STR, 5 case of PDWE and 2 cases of T2WI. The lateral ventricle was diffuse dilated (n=1) and focally dilated (n=3) in atrial area. In the comparative study, MR presented more extensive lesions in 7 cases, larger cysts in 6 cases out of 7 PVL and more definitive hemorrhage in 3 cases out of 4 cases than sonography. In conclusion MR was more valuable than sonography in evaluating the extent of lesions, size of the largest cystic lesion and detetion of hemorrhage. TIWI and STIR images were more useful in detection of PVL than T2WI and PDWI.
Diagnosis ; Discrimination (Psychology) ; Hemorrhage ; Humans ; Infant, Newborn ; Infant, Premature ; Lateral Ventricles ; Leukoencephalopathies ; Magnetic Resonance Imaging

PURPOSE: To investigate the difference in rectal complications rate following prostate low dose rate (LDR) brachytherapy based on prostate-rectum distance and prostate longitudinal length among early prostate cancer patients. MATERIALS AND METHODS: From March 2008 to February 2013, 245 prostate cancer patients with a Gleason score < or =7 were treated with 125-I LDR brachytherapy. Among them, 178 patients with prostate volume 20-35 mL and a follow-up period > or =6 months were evaluated for radiation proctitis. Magnetic resonance imaging (MRI) was performed for a prebrachytherapy evaluation, and prostate-rectum distance and prostate longitudinal length were measured. The radiation proctitis was confirmed and graded via colonoscopy based on the radiation therapy oncology group (RTOG) toxicity criteria. RESULTS: Twenty-three patients received a colonoscopy for proctitis evaluation, and 12 were identified as grade 1 on the RTOG scale. Nine patients were diagnosed as grade 2 and 2 patients were grade 3. No patient developed grade 4 proctitis. The rectal-complication group had a mean prostate-rectum distance of 2.51+/-0.16 mm, while non-rectal-complication control group had 3.32+/-0.31 mm. The grade 1 proctitis patients had a mean prostate-rectum distance of 2.80+/-0.15 mm, which was significantly longer than 2.12+/-0.31 mm of grades 2 and 3 patient groups (p=0.045). All 11 patients of grades 2 and 3 had a prostate longitudinal length of 35.22+/-2.50 mm, which was longer than group 1, but the difference was not statistically significant (p=0.214). CONCLUSIONS: As the prostate-rectum distance increased, fewer postimplantation rectal symptoms were observed. Patients with a shorter prostate-rectum distance in MRI should receive modified implantation techniques or radical prostatectomy.
Aged ; Brachytherapy/*adverse effects ; Carcinoma/*radiotherapy ; Colonoscopy ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Organ Size ; Proctitis/diagnosis/*etiology ; Prostate/*pathology ; Prostatic Neoplasms/*radiotherapy ; Radiation Injuries/diagnosis/*etiology ; Severity of Illness Index

Background/Aims: Maintaining vascular access (VA) is very important in the management of hemodialysis (HD) patients. Therefore, the identification of risk factors for decreased vascular access flow has clinical relevance. The aim of the present study was to investigate the impact of serum phosphorus (P) on autologous arteriovenous fistula flow in HD patients. Methods: Sixty-two maintenance HD patients who visited the dialysis unit of CHA Bundang Medical Center between November 2016 and December 2017 were included in the study. Serum P levels were obtained every month, and time-averaged serum P was calculated. All patients had left arm arteriovenous fistulas (AVF; side-to-side anastomosis). AVF flow was assessed by Transonic HD 03. Decreased AVF flow was defined as < 600 mL/min. Results: Decreased AVF flow was observed in 14 of 62 patients. In univariate analysis and multivariable analysis, higher serum P had a significant independent association with decreased AVF flow. Advanced age, reduced ejection fraction, low blood flow rate in dialysis, and higher serum calcium were not associated with AVF flow. Conclusions The present study demonstrated that higher serum P was an independent risk factor for decreased autologous AVF flow in maintenance HD patients. Serial monitoring of serum P may be helpful in stratifying patients by risk of AVF dysfunction, and proper management of serum P levels may be helpful in maintaining flow through autologous AVFs.

Objectives: . This study aimed to elucidate the patterns of upper airway collapse in obstructive sleep apnea (OSA) patients with a low body mass index (BMI). Methods: . We designed and conducted a retrospective cohort study. Consecutive patients diagnosed with OSA who underwent drug-induced sleep endoscopy (DISE) were included. Patients were classified into four groups according to their BMI. Age, sex, and polysomnography data were investigated. The patterns of upper airway collapse were characterized by the structures involved (soft palate, tongue base, lateral pharyngeal wall, and epiglottis). We compared the patterns of upper airway collapse in the supine and lateral decubitus position among the four BMI groups using the chi-square test and multivariate binary logistic regression analysis. Results: . A total of 627 patients (male, 517; mean age, 47.6±12.8 years) were included, consisting of 45, 79, 151, and 352 patients who were underweight or lower normal-weight (defined as the low BMI group), upper normal-weight, overweight, and obese, respectively. Severity indicators of OSA, such as the overall apnea-hypopnea index and duration of SaO2 below 90%, were significantly lower in patients with a low BMI than in obese patients, while their average oxygen saturation was significantly higher. The most common obstruction site in the supine position was the tongue base in patients with a low BMI (100%), whereas this obstruction site was significantly less common in obese patients (54.8%). Tongue base obstruction was mostly relieved in the lateral position, with no discernible obstruction in 86.7% of the low BMI patients. Conclusion . Airway obstruction in OSA patients with a low BMI is mostly due to tongue base obstruction, which improves in the lateral position. These characteristics should be kept in mind when considering treatment options for this subgroup of OSA patients.

PURPOSE: Perceived color of ceramics changes by the spectral power distribution of ambient light. This study aimed to quantify the amount of shifts in color and color coordinates of clinically simulated seven all-ceramics due to the switch of three ambient light sources using a human vision simulating spectroradiometer. MATERIALS AND METHODS: CIE color coordinates, such as L*, a* and b*,of ceramic specimens were measured under three light sources, which simulate the CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp). Shifts in color and color coordinate by the switch of lights were determined. Influence of the switched light (D65 to A, or D65 to F9), shade of veneer ceramics (A2 or A3), and brand of ceramics on the shifts was analyzed by a three-way ANOVA. RESULTS: Shifts in color and color coordinates were influenced by three factors (P<.05). Color shifts by the switch to A were in the range of 5.9 to 7.7 DeltaE*abunits, and those by the switch to F9 were 7.7 to 10.2; all of which were unacceptable (DeltaE*ab > 5.5). When switched to A, CIE a* increased (Deltaa*: 5.6 to 7.6), however, CIE b* increased (Deltab*: 4.9 to 7.8) when switched to F9. CONCLUSION: Clinically simulated ceramics demonstrated clinically unacceptable color shifts according to the switches in ambient lights based on spectroradiometric readings. Therefore, shade matching and compatibility evaluation should be performed considering ambient lighting conditions and should be done under most relevant lighting condition.
Androsterone ; Ceramics ; Humans ; Light ; Lighting ; Reading ; Vision, Ocular