Factors affecting bone mineral density in children and adolescents with secondary osteoporosis

Purpose@#This study aimed to investigate the clinical factors associated with bone mineral density (BMD) among children and adolescents with osteoporosis secondary to treatment for underlying clinical conditions. @*Methods@#We retrospectively reviewed the medical records of patients aged 10–18 years and evaluated them for lumbar spine BMD (LSBMD) after treatment for underlying diseases, including hemato-oncologic, rheumatologic system, and inflammator y bowel diseases. LSBMD measured by dual-energy x-ray absorptiometry (DXA) performed from March 2019 to March 2021 was evaluated. We analyzed 117 patients who underwent initial DXA after treatment for underlying diseases. @*Results@#Subjects in this study had multiple underlying diseases: hemato-oncologic (78.6%), rheumatologic (11.1%), and inflammatory bowel diseases (10.3%). There was no significant association between the z-score and bone metabolic markers (P>0.05). However, higher cumulative glucocorticoid (GC) dose significantly reduced LSBMD z-score (P=0.029). Moreover, the association between cumulative dose of GC and initial z-score of LSBMD was significant in logarithmic regression analysis (P=0.003, R2=0.149). GC accumulation was a significant risk factor for vertebral fracture when the initial BMD was evaluated after treatment (P=0.043). Bone metabolic markers did not significantly influence the risk of vertebral fracture. @*Conclusion@#Initial bone mass density of the lumbar spine evaluated after long-term GC use for underlying diseases is a predictor of further vertebral fractures.

Probiotic supplementation has sexdependent effects on immune responses in association with the gut microbiota in community-dwelling older adults:a randomized, double-blind, placebocontrolled, multicenter trial

BACKGROUND/OBJECTIVES@#Probiotics have been suggested as potent modulators of agerelated disorders in immunological functions, yet little is known about sex-dependent effects of probiotic supplements. Therefore, we aimed to investigate sex-dependent effects of probiotics on profiles of the gut microbiota and peripheral immune cells in healthy older adults. @*SUBJECTS/METHODS@#In a randomized, double-blind, placebo-controlled, multicenter trial, healthy elderly individuals ≥ 65 yrs old were administered probiotic capsules (or placebo) for 12 wk. Gut microbiota was analyzed using 16S rRNA gene sequencing and bioinformatic analyses. Peripheral immune cells were profiled using flow cytometry for lymphocytes (natural killer, B, CD4 + T, and CD8 + T cells), dendritic cells, monocytes, and their subpopulations. @*RESULTS@#Compared with placebo, phylum Firmicutes was significantly reduced in the probiotic group in women, but not in men. At the genus level, sex-specific responses included reductions in the relative abundances of pro-inflammatory gut microbes, including Catabacter and unclassified_Coriobacteriales, and Burkholderia and unclassified Enterobacteriaceae, in men and women, respectively. Peripheral immune cell profiling analysis revealed that in men, probiotics significantly reduced the proportions of dendritic cells and CD14 + CD16 - monocytes; however, these effects were not observed in women. In contrast, the proportion of total CD4 + T cells was significantly reduced in women in the probiotic group. Additionally, serum lipopolysaccharide-binding protein levels showed a decreasing tendency that were positively associated with changes in gut bacteria, including Catabacter (ρ = 0.678, P < 0.05) and Burkholderia (ρ = 0.673, P < 0.05) in men and women, respectively. @*CONCLUSIONS@#These results suggest that probiotic supplementation may reduce the incidence of inflammation-related diseases by regulating the profiles of the gut microbiota and peripheral immune cells in healthy elders in a sex-specific manner.

Short-term effect of growth hormone treatment in childhood leukemia survivors with growth hormone deficiency

Purpose@#Survivors of childhood leukemia are at risk of growth impairment due to intensive chemotherapy and radiation treatments. This study investigated the auxological and biochemical characteristics of childhood leukemia survivors diagnosed with growth hormone deficiency (GHD) and the changes in these parameters after 1 year of growth hormone (GH) treatment. @*Methods@#A total of 24 children diagnosed with GHD after leukemia treatment was analyzed. Clinical and biochemical data were collected retrospectively at leukemia diagnosis, GHD diagnosis, and 1 year after GH treatment. Standard deviation score (SDS) was calculated based on the age- and gender-adjusted population. @*Results@#Of the 24 children included in this study, 19 received GH treatment. The median age at GHD diagnosis was 12.3 years, and the median delay in bone age was 1.46 years. Height SDS decreased from -0.69 at leukemia diagnosis to -2.58 at GHD diagnosis (P<0.001). The change in height SDS with and without GH for 1 year was 0.35 and -0.21, respectively (P=0.044). In regression analyses, higher height SDS at GHD diagnosis and a smaller decrease of the height SDS between leukemia and GHD diagnoses were positively correlated with height SDS after GH treatment. @*Conclusion@#GH treatment could be beneficial and safe for improving height in childhood leukemia survivors with GHD. Height SDS at GHD diagnosis and reduction of height SDS between leukemia and GHD diagnosis could be potential factors in predicting the therapeutic effects. Close auxological monitoring is recommended for any childhood leukemia survivors who experience posttreatment height decline.

Adrenocortical carcinoma and a sporadic MEN1 mutation in a 3-year-old girl: a case report

Childhood adrenocortical carcinoma (ACC) is a rare disease that is mostly linked to familial cancer syndrome. Although the prevalence of ACC is extremely low in children, it is clinically important to diagnose ACC early because age and tumor stage are closely related to prognosis. From this perspective, understanding the underlying genetics and possible symptoms of ACC is crucial in managing ACC with familial cancer syndromes. In this report, we present the case of a 3-year-old girl who initially presented with symptoms of precocious puberty and was later found to have ACC by imaging analysis. On genetic analysis, the patient was found to have a MEN1 gene mutation. MEN1 mutations are found in patients with multiple endocrine neoplasia type 1 (MEN1), usually precipitating multiple endocrine tumors, including pituitary adenoma, parathyroid hyperplasia, and adrenal tumors. Although MEN1 mutation is usually inherited in an autosomal dominant manner, neither of the patient’s parents had the same mutation, making hers a case of sporadic MEN1 mutation with initial presentation of ACC. The clinical course and further investigations of this patient are discussed in detail in this report.

Transient Neonatal Diabetes Mellitus Managed with Continuous Subcutaneous Insulin Infusion (CSII) and Continuous Glucose Monitoring

Neonatal diabetes mellitus can be categorized as transient, permanent, or syndromic, and approximately half of the cases are transient. We present a case involving a term newborn who showed overt progression of transient neonatal diabetes mellitus, with complete remission within 6 months. On the second day of life, the patient presented with tachypnea, hyperglycemia, and decreased serum levels of C-peptide and insulin. Continuous subcutaneous infusion of insulin and continuous glucose monitoring were well tolerated. The patient showed a normal growth pattern, with no hyperglycemic or hypoglycemic episodes at 6 months of age. As it is rare and often asymptomatic, hyperglycemia may be attributed to various factors, including intrauterine environment, perinatal stress, and diverse genetic background. Therefore, consistent blood glucose monitoring and prompt early insulin therapy are crucial for any term newborns with persistent hyperglycemia, to prevent further diabetic complications. Moreover, continuous subcutaneous insulin infusion and the utilization of continuous glucose monitoring devices are the most effective and practical management strategies.

Effect of body mass index on peak growth hormone level after growth hormone stimulation test in children with short stature

Purpose@#The aim of this study is to evaluate the effect of body mass index (BMI) on peak serum growth hormone (GH) level after GH stimulation test in children with short stature. @*Methods@#Data were obtained from retrospective medical record reviews of those who visited the pediatric endocrine clinic at St. Vincent’s Hospital of Catholic University for short stature from January 2010 to June 2019. A total of 115 children (66 boys and 49 girls) whose height was less than the third percentile according to age and sex underwent GH stimulation testing. @*Results@#Of the 115 subjects, 47 were diagnosed with GH deficiency (GHD) and 68 were diagnosed with idiopathic short stature (ISS). In patients with GHD, weight standard deviation score (SDS) (P<0.001) and BMI SDS (P≤0.001) were higher, and free thyroxine (T4) level (P=0.012) was lower than those in the ISS group. In total subjects, peak serum GH level after GH stimulation test showed negative correlations with weight SDS (r=-0.465, P<0.001), BMI SDS (r=-0.398, P<0.001), and thyroid stimulating hormone (r=-0.248, P=0.008) and a positive correlation with free T4 (r=0.326, P<0.001). In multiple regression analysis, BMI SDS (P=0.003) was negatively associated with peak serum GH level in GH stimulation testing after adjusting for age, sex, pubertal status, and type of pharmacological stimulus. @*Conclusion@#The BMI SDS influences peak serum GH level after GH stimulation testing. We should consider BMI factors when interpreting the results of GH stimulation testing.

Transient Neonatal Diabetes Mellitus Managed with Continuous Subcutaneous Insulin Infusion (CSII) and Continuous Glucose Monitoring

Neonatal diabetes mellitus can be categorized as transient, permanent, or syndromic, and approximately half of the cases are transient. We present a case involving a term newborn who showed overt progression of transient neonatal diabetes mellitus, with complete remission within 6 months. On the second day of life, the patient presented with tachypnea, hyperglycemia, and decreased serum levels of C-peptide and insulin. Continuous subcutaneous infusion of insulin and continuous glucose monitoring were well tolerated. The patient showed a normal growth pattern, with no hyperglycemic or hypoglycemic episodes at 6 months of age. As it is rare and often asymptomatic, hyperglycemia may be attributed to various factors, including intrauterine environment, perinatal stress, and diverse genetic background. Therefore, consistent blood glucose monitoring and prompt early insulin therapy are crucial for any term newborns with persistent hyperglycemia, to prevent further diabetic complications. Moreover, continuous subcutaneous insulin infusion and the utilization of continuous glucose monitoring devices are the most effective and practical management strategies.

Effect of body mass index on peak growth hormone level after growth hormone stimulation test in children with short stature

Purpose@#The aim of this study is to evaluate the effect of body mass index (BMI) on peak serum growth hormone (GH) level after GH stimulation test in children with short stature. @*Methods@#Data were obtained from retrospective medical record reviews of those who visited the pediatric endocrine clinic at St. Vincent’s Hospital of Catholic University for short stature from January 2010 to June 2019. A total of 115 children (66 boys and 49 girls) whose height was less than the third percentile according to age and sex underwent GH stimulation testing. @*Results@#Of the 115 subjects, 47 were diagnosed with GH deficiency (GHD) and 68 were diagnosed with idiopathic short stature (ISS). In patients with GHD, weight standard deviation score (SDS) (P<0.001) and BMI SDS (P≤0.001) were higher, and free thyroxine (T4) level (P=0.012) was lower than those in the ISS group. In total subjects, peak serum GH level after GH stimulation test showed negative correlations with weight SDS (r=-0.465, P<0.001), BMI SDS (r=-0.398, P<0.001), and thyroid stimulating hormone (r=-0.248, P=0.008) and a positive correlation with free T4 (r=0.326, P<0.001). In multiple regression analysis, BMI SDS (P=0.003) was negatively associated with peak serum GH level in GH stimulation testing after adjusting for age, sex, pubertal status, and type of pharmacological stimulus. @*Conclusion@#The BMI SDS influences peak serum GH level after GH stimulation testing. We should consider BMI factors when interpreting the results of GH stimulation testing.

Effects of self-ligating brackets and other factors influencing orthodontic treatment outcomes: A prospective cohort study / 대한치과교정학회지

Objective@#The purpose of this study was to evaluate the effects of self-ligating brackets (SBs) and other factors that influence orthodontic treatment outcomes. @*Methods@#This two-armed cohort study included consecutively treated patients in a private practice. The patients were asked to choose between SBs and conventional brackets (CBs); if any patient did not have a preference, he or she was randomly allocated to the CB or SB group. All patients were treated using an identical archwire sequence. Evaluated parameters were as follows: treatment duration, number of bracket failures, poor oral hygiene, poor elastic wear, extraction, use of orthodontic mini-implants (OMI), OMI failure, American Board of Orthodontics (ABO) Discrepancy Index (DI), arch length discrepancy, and ABO Cast-Radiograph Evaluation (CRE) score. Stepwise regression analysis was performed to generate the equation for prediction of the CRE. @*Results@#The final sample comprised 134 patients with an average age of 22.73 years. The average DI, CRE, and treatment duration were 21.81, 14.25, and 28.63 months, respectively. Analysis of covariance showed a significant difference in CRE between the CB and SB groups after adjusting for the effects of confounding variables. Stepwise regression analysis using four variables, namely extraction, SB use, poor elastic wear, and additional appliance use, could explain only 25.2% of the variance in the CRE. @*Conclusions@#Although the CRE was significantly better for CBs than for SBs, the clinical significance of this result seems to be limited. Extraction, SB use, poor elastic wear, and additional appliance use may have significant effects on treatment outcomes.

A case of 45,X/47,XXX mosaic Turner syndrome: Clinical manifestations and effect of growth hormone treatment

In Turner syndrome (TS), 45,X/47,XXX mosaicism is a rare genotype. Due to its low frequency, the clinical features and prognosis are not clearly known. A 10-year-old girl was diagnosed with 45,X/47,XXX mosaicism TS and presented with short stature. She did not show any other TS phenotypic features, except for short stature, and developed spontaneous puberty and menarche, although she had unilateral ovarian agenesis. She achieved a significant growth improvement following growth hormone treatment. Since 45,X/47,XXX mosaic TS shows different gonadal function from that of classic TS, it is necessary to conduct surveillance for premature ovarian insufficiency.

Predicting First-Year Growth in Response to Growth Hormone Treatment in Prepubertal Korean Children with Idiopathic Growth Hormone Deficiency: Analysis of Data from the LG Growth Study Database

Background@#The first-year growth in response to growth hormone (GH) treatment seems to be the most important factor in determining the overall success of GH treatment. @*Methods@#Data from children (n = 345) who were in the LG Growth Study Database were used to develop a model. All subjects had been diagnosed with idiopathic growth hormone deficiency (GHD) and presented in a prepubertal state during the first year of GH treatment. @*Results@#The Δheight standard deviation score (SDS) during 1st year of GH treatment was correlated positively with weight-SDS (β = 0.304, P < 0.001), body mass index (BMI)-SDS (β = 0.443, P < 0.001), paternal height-SDS (β = 0.296, P = 0.001), MPH-SDS (β = 0.421, P < 0.001) and MPH SDS minus baseline height SDS (β = 0.099, P < 0.001) but negatively with chronological age (β = −0.294, P < 0.001), bone age (β = −0.249, P < 0.001). A prediction model of 1st year growth in response to GH treatment in prepubertal Korean children with idiopathic GHD is as follows: Δheight SDS during 1st year of GH treatment = 1.06 − 0.05 × age + 0.09 × (MPH SDS minus baseline height SDS) + 0.05 × BMI SDS. This model explained 19.6% of the variability in the response, with a standard error of 0.31. @*Conclusion@#The present model to predict first-year response to GH treatment might allow more tailored and personalized GH treatment in Korean prepubertal children with idiopathic GHD.

Growth patterns over 2 years after birth according to birth weight and length percentiles in children born preterm

Purpose@#To analyze growth patterns over 2 years after birth according to preterm infant birth weight and length percentiles. @*Methods@#Anthropometric measurements of 82 preterm infants were retrospectively reviewed. Preterm infants with birth weight or length below the 10th percentile were classified as small for gestational age (SGA) (n=19) and those between the 10th and 89th percentile as appropriate for gestational age (AGA) (n=63). The association between the length standard deviation score (SDS) at 2 years of corrected age and clinical factors were analyzed. @*Results@#The length SDS of the SGA group was significantly increased at 6 months (-1.30±1.71) and 24 months (-0.97±1.06) of corrected age. The length SDS was lower in the SGA group than those in the AGA group at 6 months (-1.30±1.71 vs. -0.25±1.15, P=0.004), 18 months (-0.97±1.39 vs. -0.03±1.29, P=0.015), and 24 months (-0.97±1.06 vs. -0.29±1.12, P=0.022,). The percentage of children with a length SDS of <-2 (growth failure) at 24 months was 15.8% in the SGA group and 4.8% in the AGA group (P=0.108). Multiple linear regression analysis demonstrated that length at 24 months of corrected age was negatively correlated with birth length below the 10th percentile (coefficient β=-0.91, P=0.001) and duration of stay in the neonatal intensive care unit (NICU) (coefficient β=-0.01, P=0.001). @*Conclusion@#Despite the fact that catch-up growth occurs during the early period of infancy in a large portion of preterm SGA infants, a significant portion of these infants show growth failure at 24 months of age. Growth over 2 years after birth is affected by birth length and duration of stay in the NICU in preterm children.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

Purpose@#Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and ‘fixed cutoff point’ (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS). @*Methods@#Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010–2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP. @*Results@#Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweightormal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR. @*Conclusion@#The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Discriminatory performance of insulin-like growth factor 1 and insulin-like growth factor binding protein-3 by correlating values to chronological age, bone age, and pubertal status for diagnosis of isolated growth hormone deficiency

Purpose@#The discriminatory performance of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated by correlating their values with chronological age (CA), bone age (BA), and pubertal status (PS) for diagnosis of isolated growth hormone deficiency (IGHD). @*Methods@#We evaluated IGF-1 and IGFBP-3 levels in 310 short-stature subjects subdivided into 2 groups: IGHD (n=31) and non-IGHD (n=279). IGF-1 and IGFBP-3 were assayed using immune-radiometric assay and transformed into standard deviation score (SDS) according to CA, BA, and PS. @*Results@#The highest sensitivity was found in IGF-1-SDS for CA and IGFBP-3-SDS for CA (22.6% and 30.0%, respectively). The highest specificity was found in IGF-1-SDS for PS and IGFBP-3-SDS for PS (98.2% and 94.4%, respectively). Groups with the highest positive predictive values were IGF-1-SDS for BA and IGFBP-3-SDS for BA (10.9% and 5.1%, respectively). Highest negative predictive values were seen in IGF-1-SDS for CA and IGFBP-3-SDS for CA (98.4% and 98.4%, respectively). @*Conclusion@#IGF-1-SDS for CA, instead of IGF-1-SDS for BA or PS, could be used as a standard variable for IGHD screening. The sufficiently high specificity of IGF-1-SDS for PS suggests that this value is a useful tool for identification of IGHD.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

Purpose@#Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and ‘fixed cutoff point’ (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS). @*Methods@#Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010–2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP. @*Results@#Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweightormal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR. @*Conclusion@#The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Discriminatory performance of insulin-like growth factor 1 and insulin-like growth factor binding protein-3 by correlating values to chronological age, bone age, and pubertal status for diagnosis of isolated growth hormone deficiency

Purpose@#The discriminatory performance of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated by correlating their values with chronological age (CA), bone age (BA), and pubertal status (PS) for diagnosis of isolated growth hormone deficiency (IGHD). @*Methods@#We evaluated IGF-1 and IGFBP-3 levels in 310 short-stature subjects subdivided into 2 groups: IGHD (n=31) and non-IGHD (n=279). IGF-1 and IGFBP-3 were assayed using immune-radiometric assay and transformed into standard deviation score (SDS) according to CA, BA, and PS. @*Results@#The highest sensitivity was found in IGF-1-SDS for CA and IGFBP-3-SDS for CA (22.6% and 30.0%, respectively). The highest specificity was found in IGF-1-SDS for PS and IGFBP-3-SDS for PS (98.2% and 94.4%, respectively). Groups with the highest positive predictive values were IGF-1-SDS for BA and IGFBP-3-SDS for BA (10.9% and 5.1%, respectively). Highest negative predictive values were seen in IGF-1-SDS for CA and IGFBP-3-SDS for CA (98.4% and 98.4%, respectively). @*Conclusion@#IGF-1-SDS for CA, instead of IGF-1-SDS for BA or PS, could be used as a standard variable for IGHD screening. The sufficiently high specificity of IGF-1-SDS for PS suggests that this value is a useful tool for identification of IGHD.

Total arch distalization with interproximal stripping in a patient with severe crowding / 대한치과교정학회지

When a patient shows severe crowding, premolar extraction should be considered to provide required available space for alignment. If the third molars have already erupted and demonstrate a poor prognosis, third molar extraction and distalization of the posterior dentition can be used instead of premolar extraction to obtain space. Interproximal stripping (IPS) may also be used to gain space in cases of crowding. This case report describes the treatment of a 25-year-old man with severe crowding and mild lip protrusion. Although the crowding in the lower arch was severe enough to require first premolar extraction, distalization of the entire lower dentition with orthodontic mini-implants, extraction of the lower third molars, and IPS could successfully resolve the crowding and lip protrusion.

Obesity Prevalence in Pediatric Headaches / 대한소아신경학회지

PURPOSE: Obesity and headache are two highly prevalent diseases both in childhood and adolescent. In this study, we assessed the prevalence of obesity in pediatric headaches patients in a single institution in Korea, and differences according to age, sex, headache type, frequency, intensity, and disability. METHODS: We retrospectively reviewed the medical records of 340 subjects (6–18 years of age) who visited the Pediatric Headache Clinic of Bucheon St. Mary's Hospital during the period from January 2015 through March 2018. Data on age, sex, height and weight, as well as headache type, frequency, intensity and disability, were collected. Body Mass Index (BMI) percentile was calculated based on the 2017 Korean Children Adolescence Growth Chart. RESULTS: 17.6% of the pediatric headache patients were obese. The prevalence of obesity in male patients was higher than females (Male 23.8% VS Female 11.6%, P=0.002). There were no significant differences in obesity rate according to age, headache type, frequency, intensity, and disability. CONCLUSION: The prevalence of obesity in the pediatric headache population was 17.6% which is higher than 10.1% in general population (Korea National Health and Nutrition Examination Survey, KNHANES, 2013).

Factors affecting height velocity in normal prepubertal children

PURPOSE: To analyze the effects of clinical and laboratory factors, including insulin-like growth factor (IGF) levels, on the height velocity of normal prepubertal children. METHODS: Ninety-five healthy prepubertal children (33 boys, 62 girls) were enrolled. The mean chronological age was 6.3±1.4 years, with a height standard deviation score (SDS) of -0.88±0.70. IGF-1, IGF binding protein-3 (IGFBP-3), SDS for anthropometric measurements, and changes in SDS for anthropometric measurements were analyzed for 1 year, and their associations with 1-year height velocity were investigated. RESULTS: The group of children with a 1-year height velocity of ≥6 cm were chronologically younger than the group with a 1-year height velocity of < 6 cm (5.9±1.3 years vs. 6.7±1.3 years, P=0.004), with a lesser increase of SDS for body mass index (BMI) over 1 year (-0.18±0.68 vs. 0.13±0.53, P=0.014). There were no differences between the 2 groups in IGF-1 SDS and IGFBP-3 SDS. Multiple linear regression showed that baseline chronological age (r=0.243, P=0.026) and height SDS (r=0.236, P=0.030) were positively associated with IGF-1 SDS. Binomial logistic regression showed that an older chronologic age at referral (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.47–0.99) and an increase of BMI SDS over 1 year (OR, 0.41; 95% CI, 0.18–0.89) were associated with a decreased growth possibility of an above-average height velocity (≥6 cm/yr). CONCLUSIONS: Height velocity of normal prepubertal children is affected by an increase of BMI SDS and chronological age. Prepubertal IGF-1 SDS reflects height SDS at the time of measurement but is not associated with subsequent height velocity.

Comparison of mechanical and biological properties of zirconia and titanium alloy orthodontic micro-implants / 대한치과교정학회지

OBJECTIVE: The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. METHODS: Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of 0°, 10°, 20°, 30°, and 40°. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. RESULTS: There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was 56.88 ± 6.72%. CONCLUSIONS: Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.