Camouflage treatment of posterior bite collapse in a patient with skeletal asymmetry by using posterior maxillary segmental osteotomy / 대한치과교정학회지

Orthodontic treatment of posterior bite collapse due to early loss of molars and the consequent drift of adjacent teeth is complicated. When the posterior bite collapse occurs in patients with facial asymmetry, both transverse and vertical compensation are necessary for camouflage orthodontic treatment. In such cases, posterior maxillary segmental osteotomy (PMSO) can be an effective alternative procedure that simplifies the orthodontic treatment and shows long-term stability through dental compensation within the alveolar bone housing. This case report aimed to describe the orthodontic treatment of maxillary occlusal plane canting caused by severely extruded maxillary teeth in a patient with skeletal facial asymmetry that was corrected with PMSO along with protraction of the lower second molar to replace the space of the extracted first molar. The treatment duration was 18 months, and stable results were obtained after 2 years of retention.

Surface analysis of metal clips of ceramic self-ligating brackets / 대한치과교정학회지

OBJECTIVE: The aim of this study was to analyze the surface composition, roughness, and relative friction of metal clips from various ceramic self-ligating brackets. METHODS: Six kinds of brackets were examined. The control group (mC) consisted of interactive metal self-ligating brackets while the experimental group (CC, EC, MA, QK, and WA) consisted of interactive ceramic self-ligating brackets. Atomic force microscopy-lateral force microscopy and scanning electron microscopy-energy-dispersive X-ray spectroscopy were used to analyze the surface of each bracket clip. RESULTS: All the clips in the experimental groups were coated with rhodium except for the QK clip. The results showed that the QK clip had the lowest average roughness on the outer surface, followed by the MA, EC, WA, and CC clips. However, the CC clip had the lowest average roughness on the inner surface, followed by the QK, WA, MA, and EC clips. The QK clip also had the lowest relative friction on the outer surface, followed by the MA, EC, CC, and WA clips. Likewise, the CC clip had the lowest relative friction on the inner surface, followed by the QK, WA, MA, and EC clips. CONCLUSIONS: The surface roughness and relative friction of the rhodium-coated clips were generally higher than those of the uncoated clips.

Predictors of favorable soft tissue profile outcomes following Class II Twin-block treatment / 대한치과교정학회지

OBJECTIVE@#The aim of this study was to determine cephalometric factors that help predict favorable soft-tissue profile outcomes following treatment with the Class II Twin-block appliance.@*METHODS@#Pre- and post-treatment lateral cephalograms of 45 patients treated with the Class II Twin-block appliance were retrospectively analyzed. Profile silhouettes were drawn from the cephalograms and evaluated by three orthodontists in order to determine the extent of improvement. Samples were divided into a favorable group (upper 30% of visual analogue scale [VAS] scores, n = 14) and an unfavorable group (lower 30% of VAS scores, n = 14). Skeletal and soft-tissue measurements were performed on the cephalograms and an intergroup comparison was conducted.@*RESULTS@#An independent t-test revealed that the following pre-treatment values were lower in the favorable group compared to the unfavorable group: lower incisor to mandibular plane angle, lower incisor to pogonion distance, point A-nasion-point B angle, sella-nasion line (SN) to maxillary plane angle, SN to mandibular plane angle, gonial angle, and symphysis inclination. The favorable group had a larger incisor inclination to occlusal plane. Moreover, the favorable group showed larger post-treatment changes in gonial angle, B point projection, and pogonion projection than did the unfavorable group.@*CONCLUSIONS@#Class II malocclusion patients with a low divergent skeletal pattern and reduced lower incisor protrusions are likely to show more improvement in soft-tissue profile outcomes following Class II Twin-block treatment.

Baseline-Corrected QT (QTc) Interval Is Associated with Prolongation of QTc during Severe Hypoglycemia in Patients with Type 2 Diabetes Mellitus

BACKGROUND: We investigated an association between baseline heart rate-corrected QT (QTc) interval before severe hypoglycemia (SH) and prolongation of QTc interval during SH in patients with type 2 diabetes mellitus (T2DM). METHODS: Between January 2004 and June 2014, 208 patients with T2DM, who visited the emergency department because of SH and underwent standard 12-lead electrocardiography within the 6-month period before SH were consecutively enrolled. The QTc interval was analyzed during the incidence of SH, and 6 months before and after SH. QTc intervals of 450 ms or longer in men and 460 ms or longer in women were considered abnormally prolonged. RESULTS: The mean age and diabetes duration were 68.1±12.1 and 14.1±10.1 years, respectively. The mean QTc intervals at baseline and SH episodes were 433±33 and 460±33 ms, respectively (P<0.001). One hundred and fourteen patients (54.8%) had a prolonged QTc interval during SH. There was a significant decrease in the prolonged QTc interval within 6 months after SH (QTc interval prolongation during SH vs. after recovery, 54.8% vs. 33.8%, P<0.001). The prolonged QTc interval was significantly associated with baseline QTc interval prolongation (odds ratio, 2.92; 95% confidence interval, 1.22 to 6.96; P=0.016) after adjusting for multiple confounders. CONCLUSION: A prolonged QTc interval at baseline was significantly associated with prolongation of the QTc interval during SH in patients with T2DM, suggesting the necessity of QTc interval monitoring and attention to those with a prolonged QTc interval to prevent SH.

Analysis of midpalatal miniscrew-assisted maxillary molar distalization patterns with simultaneous use of fixed appliances: A preliminary study / 대한치과교정학회지

Skeletal anchorage-assisted upper molar distalization has become one of the standard treatment modalities for the correction of Class II malocclusion. The purpose of this study was to analyze maxillary molar movement patterns according to appliance design, with the simultaneous use of buccal fixed orthodontic appliances. The authors devised two distinct types of midpalatal miniscrew-assisted maxillary molar distalizers, a lingual arch type and a pendulum type. Fourteen patients treated with one of the two types of distalizers were enrolled in the study, and the patterns of tooth movement associated with each type were compared. Pre- and post-treatment lateral cephalograms were analyzed. The lingual arch type was associated with relatively bodily upper molar distalization, while the pendulum type was associated with distal tipping with intrusion of the upper molar. Clinicians should be aware of the expected tooth movement associated with each appliance design. Further well designed studies with larger sample sizes are required.

Prediction of the Response to Proton Pump Inhibitor Treatment Using Wireless Ambulatory pH Monitoring in Patients with Globus Sense / 대한소화기학회지

BACKGROUND/AIMS: Globus is a persistent or intermittent non-painful sensation of a lump or foreign body in the throat and a commonly encountered clinical condition. We aim to evaluate the prevalence of gastroesophageal reflux disease (GERD) and to determine the parameters for predicting the response to treatment with proton pump inhibitor (PPI) using wireless pH monitoring in patients with globus sense. METHODS: We retrospectively reviewed the medical records of 37 patients with atypical GERD symptoms. A total of 27 patients with dominant globus sense were enrolled. Endoscopic examination and 48-hour wireless esophageal pH monitoring were performed, and the patients underwent a therapeutic trial of full dose PPIs daily over a period of 4 weeks. RESULTS: Both typical and atypical GERD symptoms co-existed in 14 patients (51.9%, 14/27). According to ROME III criteria, 19 patients (70.4%, 19/27) were diagnosed as GERD. Twelve patients (44.4%, 12/27) were PPI responders. A significant difference in the frequency of symptom index (+) or symptom associated probability (+) was observed between the PPI responder group and the non-responder group (p<0.01). CONCLUSIONS: In patients with globus sense, 70.4% were diagnosed with GERD. Symptom index/symptom associated probability in wireless ambulatory pH monitoring was a good objective parameter for PPI responder.

Current Status and Clinical Impact of Pediatric Endoscopy in Korea / 대한소화기학회지

BACKGROUND/AIMS: In pediatrics, endoscopic examination has become a common procedure for evaluation of gastrointestinal presentations. However, there are limited data on pediatric endoscopy in Korea. The aim of this study was to analyze the current status and clinical impacts of endoscopic examination in children and adolescents. METHODS: We retrospectively reviewed the medical records of outpatients who visited the tertiary hospital. Patients under 18 years of age who underwent endoscopy were included. Endoscopic findings were classified as specific and normal based on gross findings. Specific endoscopic findings were reflux esophagitis, peptic ulcers, and Mallory-Weiss tear. Other findings included acute gastritis classified according to the updated Sydney system. RESULTS: In 722 of 330,350 patients (0.2%), endoscopic examination (554 esophagogastroduodenoscopies [EGDs], 121 colonoscopies, 47 sigmoidoscopies) was performed between January 2008 and January 2013. In EGD, abdominal pain was the most frequent presentation (64.1%). The most common diagnosis was gastritis (53.2%), followed by reflux esophagitis. The frequency of peptic ulcer disease was 12.8%. Frequent symptoms leading to colonoscopic examination were abdominal pain, diarrhea, and hematochezia. In colonoscopy, a negative result was more likely in children younger than 7 years old. After the procedure, the diagnostic yield of EGD and colonoscopy was 88.1% and 45.8%, respectively, and the rate of change in management was 67.1%. CONCLUSIONS: In pediatrics, endoscopic examination was useful for the choice of therapeutic strategy and it would be a standard method for evaluation of gastrointestinal presentation.

Histologic assessment of the biological effects after speedy surgical orthodontics in a beagle animal model: a preliminary study / 대한치과교정학회지

OBJECTIVE: Speedy surgical orthodontics (SSO), an innovative orthodontic treatment, involves the application of orthopedic forces against temporary skeletal anchorage devices following perisegmental corticotomy to induce movement of specific dental segments. Herein, we report the biological effects of SSO on the teeth and periodontal structures. METHODS: Five beagle dogs were divided into 2 groups and their 6 maxillary incisors were retracted en masse by applying 500 g orthopedic force against a single palatal mini-plate. Retraction was performed without and with perisegmental corticotomy in groups I and II, respectively. All animals were killed on the 70th day, and their periodontal structures were processed for histologic analyses and scanning electronic microscopy (SEM). The linear distance between the third maxillary incisor and canine was used as a benchmark to quantify the retraction amount. RESULTS: Retraction was markedly faster and retraction amount greater in group II than in Group I. Surprisingly, Group II did not show any root resorption despite extensive retraction, while Group I showed prominent root surface irregularities. Similarly, SEM showed multiple resorption lacunae in Group I, but not in Group II. CONCLUSIONS: SSO is an effective and favorable orthodontic approach for major en masse retraction of the maxillary anterior teeth.

Effects of compressive stress on the expression of M-CSF, IL-1beta, RANKL and OPG mRNA in periodontal ligament cells / 대한치과교정학회지

OBJECTIVE: The aim of this study was to determine if human PDL cells can produce osteoclastogenic mRNA and examine how compressive stress affects the expression of osteoclastogenic mRNA in human PDL cells. METHODS: Human PDL cells were obtained from biscupids extracted for orthodontic treatment. The compressive force was adjusted by increasing the number of cover glasses. PDL cells were subjected to a compressive force of 0.5, 1.0, 2.0, 3.0 or 4.0 g/cm2 for 0.5, 1.5, 6, 24 or 48 hours. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to examine levels of M-CSF, IL-1beta, RANKL, OPG mRNA expression. RESULTS: Human PDL cells could produce M-CSF mRNA. Human PDL cells under compressive stress showed increased M-CSF, IL-1beta and RANKL mRNAs expression in a force (up to 2 g/cm2) and time-dependent manner. However, OPG mRNA expression was constant regardless of the level and duration of stress. CONCLUSIONS: Continuous compressive stress induced the mRNA expression of osteoclastogenic cytokines including M-CSF, RANKL, IL-1beta in PDL cells. Together with an unchanged OPG mRNA level, these results suggest that compressive stress-induced osteoclastogenesis in vivo is partly controlled by M-CSF, RANKL and IL-1beta expression in PDL cells.

Maturation of cervical vertebrae in relation to menarche / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to investigate the relationship between menarche and cervical vertebral maturation. METHODS: Lateral cephalograms of 67 young korean girls within the range of 1 year before or after their menarche were gathered. The concavity of the cervical vertebrae base and the ratio of the base length to the 3rd and 4th cervical vertebrae anterior height were measured and analyzed. RESULTS: The mean measured values were as follows; concavity of the 3rd cervical vertebrae base: 1.27 (+/- 0.18) mm, concavity of the 4th cervical vertebrae base: 1.06 (+/- 0.15) mm, ratio of the base length to the 3rd cervical vertebrae anterior height: 0.73 (+/- 0.06) and ratio of the base length to the 4th cervical vertebrae anterior height: 0.70 (+/- 0.05). There was a significant increase in the ratio of the base length to the 3rd vertebrae anterior height and the base concavity of the 3rd and 4th cervical vertebrae during the period of 1 year before to 1 year after their menarche. CONCLUSIONS: These characteristics of the 3rd and 4th cervical vertebrae on the lateral cephalogram can provide useful clues on evaluating the growth stage.

Menarcheal timing and growth curve shape during the adolescent growth spurt / 대한치과교정학회지

OBJECTIVE: This study investigated the onset, peak height velocity (PHV) and end of adolescent growth spurt as well as menarcheal timing deduced from surveying accumulative height growth over many years. METHODS: Ninety six students of Samgoe high school between 1st and 3rd grade that were in good health participated in the research. A survey questionnaire was distributed to examine the students' health status and menarche timing. RESULTS: Adolescent growth spurt typically began at the age of 9.9 and reached a PHV at the age of 11.6. The growth spurt ended at the age of 14.1 on average. The average age of menarche was 12.6 years, which was about one year after the PHV of adolescent growth spurt. In most cases, menarche came after PHV. But in 24% of the students, menarche and PHV was nearly coincident or menarche preceded PHV. The growth curves were classified into four types. A typical adolescent growth spurt showed one PHV on graph that drastically drops after the PHV. However, there were cases with two PHVs. CONCLUSIONS: The results indicate that individual growth patterns show large individual differences, however the categorization into the various growth curves may aid in predicting individual growth patterns.

Bone-implant contact and mobility of surface-treated orthodontic micro-implants in dogs / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. METHODS: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150 - 200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using Periotest(R). RESULTS: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. CONCLUSIONS: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.

Effects of surface treatment on the osseointegration potential of orthodontic mini-implant / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to compare the torque resistance to removal of sandblasted large grit and acid etched (SLA) surface treated orthodontic mini-implants and smooth surface orthodontic mini-implants as well as performing histologic observations. METHODS: Two groups of custom screw shaped orthodontic mini-implants (C-implant, 1.8 mm outer diameter x 9.5 mm length, Cimplant, Seoul, Korea) were designated. 22 SLA treated C-implants (SLA group) and 22 machined surface C-implants (machined group) were placed in the tibia metaphysis of 11 adult New Zealand white rabbits. Following a 6-week healing period, the rabbits were sacrificed. Subsequently, the C-implants were removed under reverse torque rotation with a digital torque measuring device and independent t-test was performed. Selected tissues were prepared for histologic observation. RESULTS: The SLA group presented a higher mean removal torque value (6.286 Ncm) than the machined group (4.491 Ncm) which was statistically significant (p < 0.005). Histologic observation revealed a trend of more new bone formation in contact with the screw surface in the SLA group than the smooth group. CONCLUSIONS: The results of this study suggested that SLA surface treatment can enhance the osseintegration potential for C-orthodontic mini-implants.

Influence of immediate loading on the removal torque value of mini-screws / 대한치과교정학회지

OBJECTIVE: The purpose of this experimental study was to evaluate the effect of immediate orthodontic loading on the stability at the bone-implant interface of titanium miniscrews in a rabbit model. METHODS: Forty titanium miniscrews (1.6 mm diameter, 8 mm length) were inserted in the tibiae of 10 rabbits. Twenty test group miniscrews were subjected to continuous orthodontic forces of 200 g immediately after implantation for a period of 6 weeks. The remaining 20 control group miniscrews were left unloaded for the same follow-up interval. Removal torque values were recorded using a digital torque gauge. An independent t-test was performed. RESULTS: All the miniscrews were stable, and exhibited no mobility or displacement throughout the experimental period. Histologically, miniscrews were well-integrated into bone. No statistically significant differences in removal torque data were found between the loaded test and the unloaded control groups. CONCLUSIONS: These findings suggest that titanium miniscrews can be used as anchoring units for orthodontic tooth movement immediately after insertion.

The frontal characteristics of esthetic lips and lips after anterior segmental osteotomy in Korean females / 대한치과교정학회지

OBJECTIVE: The aim of this study was to determine firstly the characteristics of esthetic lips in Korean females and secondly to measure the changes of the lips before and after anterior segmental osteotomy in bimaxillary protruded patients. METHODS: Samples consisted of 30 models and 26 nonmodels, and 10 patients who had received anterior segmental osteotomy. Twelve linear measurements, 5 angular measurements, and the lip perimeter and area were measured. These results were compared for each group using unpaired and paired t-tests. RESULTS: Full face width, nose to chin, upper vermilion height and angle, lateral heights at the point of the tips of Cupid's bow, central bow angle, and the lower lip to chin lengths were significantly greater in nonmodels than in models. However, overall lip width, lower vermilion height and angle, tip-to-tip of Cupid's bow lip perimeter, and lower vermilion area were greater in models than in nonmodels. Comparison of before and after anterior segmental osteotomy revealed that the values for the upper vermilion and lateral heights, the angle to Cupid's bow tip lengths, and upper vermilion area of post-operative patients had become similar to those of Korean female models. Our findings demonstrated that Korean female models have a fuller lower vermilion & thinner upper vermilion compared with nonmodel controls, as determined by the vermilion heights, angles, and areas. CONCLUSIONS: It will be helpful for clinicians to use these measurements as guidelines for improving patients' facial esthetics.

Comparison of arch forms between Korean and Japanese in Class I, II, and III malocclusion / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to compare arch dimensions and frequency distribution of arch forms between Korean and Japanese Class I, II, and III malocclusion groups. METHODS: The sample consisted of 368 Korean cases (114 Class I, 119 Class II, and 135 Class III malocclusion) and 160 Japanese cases (60 Class I, 50 Class II, and 50 Class III malocclusion). The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket slot points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. Measurements are statistically analyzed in each malocclusion group. The dental arches were classified into square, ovoid, and tapered forms to determine and compare the frequency distributions between the two ethnic groups. RESULTS: The findings of this study showed that Japanese females in Class I and II groups had a statistically significant narrower mandibular dental arch width compared with the Japanese males, Korean males and Korean females. But in the Class III group, there was no significant difference in the mandibular dental arch size according to the two ethnic groups and genders. CONCLUSIONS: The majority of Koreans and Japanese in all the malocclusion groups exhibited square and ovoid arch forms. The most frequent arch forms found in Koreans was square but ovoid for Japanese.

Clinical considerations with self-ligating brackets / 대한치과교정학회지

Self-ligating brackets have a permanently installed movable component to entrap the archwire which reduces much of the friction created by conventional ligation. Therefore, it allows for rapid tooth movement and shorter overall treatment time. Due to these advantages, interest in self-ligating brackets is increasing. In this report, several practical considerations for using self-ligating brackets are given to appreciate and maximize their benefits. It is thought that self-ligating brackets make shorter and more efficient treatment possible.

The effect of indomethacin on the matrix metalloproteinases in canine permanent tooth eruption / 대한치과교정학회지

Tooth eruption requires remodeling of surrounding tissues. This study was aimed to investigate the effect of indomethacin on the dental follicle and paradental tissues during tooth eruption by observing the distribution and expression of MMP by the immunohistochemical method. Ten mongrel dogs of ten to twelve weeks old were divided into 5 groups; four experimental groups administered indomethacin 2 mg/Kg/day and 8 mg/Kg/day orally 2 times a day for 14 days and 7 days respectively, and the control group was administered a placebo. Permanent teeth before eruption and their surrounding tissues were selected and excised. H and E staining and immunohistochemical stainings of MMP-3 and -9 were performed and examined under the light microscope. Osteoclasts, osteoblasts, periodontal ligament cells, ameloblasts and odontoblasts of the control group all expressed MMP-3 and -9. In the experimental group, osteoclasts, osteoblasts and periodontal ligament cells showed reduced expression of MMP-3 and -9. Magnitude of MMP reduction in the experimental group showed a time and dose of indomethacin administration dependent manner. These results show that indomethacin inhibited MMP-3 and -9 expression in the dental follicle and surrounding tissues and suggest that when indomethacin is administered for long periods, tooth eruption could be delayed.

Removal torque of sandblasted large grit, acid etched treated mini-implant / 대한치과교정학회지

OBJECTIVE: The purposes of this study were to evaluate the differences between sand blasted, large grit and acid-etched (SLA) treated mini-implants and smooth surface orthodontic mini-implants in relation to the removal torque as well as the histologic analysis. METHODS: Custom-made, screw-shaped, titanium implants with a length of 9.5 mm and an outer diameter of 1.8 mm were divided into 2 groups; the SLA group (20 SLA treated orthodontic mini-implants) and the smooth surface group (20 smooth surface mini-implants), and placed in the tibia metaphysis of 10 rabbits. Each rabbit had 4 mini-implants placed, 2 in each tibia. The right tibia were implanted with the SLA group mini-implants and the left tibia had the smooth group mini-implants placed. Each mini-implant group were immediately applied with a continuous traction force of 150 g using a Ni-Ti coil spring. The rabbits were sacrificed 6 weeks post-surgically. Subsequently, the legs were stabilized, the Ni-Ti coil springs were removed and the mini-implants were removed under reverse torque rotation with a digital torque gauge. RESULTS: 6 weeks after placement, the SLA group presented a higher mean removal torque value (8.29 Ncm) than the smooth group (3.34 Ncm) and histologic analysis revealed a higher new bone formation aspect along the screw in the SLA group. CONCLUSION: Results of this study indicates that SLA treated mini-implants may endure higher orthodontic forces without loosening.

Effects of Indomethacin on the physiologic root resorption of deciduous teeth in dogs / 대한치과교정학회지

This study was aimed to investigate the effects of indomethacin on physiologic root resorption and to examine the dental pulp and tissue changes around the resorbing teeth. 13-14 week old six mongrel dogs were divided into 3 groups; two experimental groups administered indomethacin 2 mg/kg/day and 8 mg/kg/day orally two times a day for 14 days respectively, and control group administered a placebo. The deciduous incisors showing root resorption were selected, fixed for 24 hrs in 10% formalin solution, demineralized in 10% EDTA solution, invested in paraffin and sectioned in 5 micrometer thick sections. The preparations were stained with H and E staining and Masson's trichrome staining and examined under the light microscope. Observation revealed that deciduous root resorbing tissue resembles inflammatory tissue and accompanies bone remodelling. The dental pulp was normal except the area near root resorption, well organized columnar odontoblasts layer under the predentin, and the odontoblasts near root resorption were cuboidal or flat cells in the disrupted layer under the predentin. Indomethacin administered group showed a partial decrease in the number of odontoclasts and nucleus. But there was no sign of pulp change by indomethacin. These results suggest that indomethacin inhibits recruitment of odontoclasts partially and that of osteoclasts more, and so when it is administered for long periods, deciduous root resorption can be delayed and eruption of the successor can be delayed for a short period.