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Objectives The purpose of this retrospective study was to evaluate the accuracy of intraoral scan (IOS) images in the maxillary and mandibular arches with orthodontic brackets. Material and methods From digital impressions of 140 patients who underwent orthodontic treatment, consecutive IOS images were selected based on standardized inclusion criteria: Two pre-orthodontic IOS images (IOS1 and IOS2) of permanent dentition with fully erupted second molars and IOS images obtained immediately after orthodontic bracket bonding (IOSb). Superimpositions were performed to evaluate the reproducibility of repeated IOS images. Accuracy of IOSb images was analyzed by comparing the average surface errors between IOS1c and IOS2c images, which were IOS images cut based on the same region of the interest as between IOS1 and IOSb images. Results A total of 84 IOS images was analyzed. The average surface errors between IOS1 and IOS2 images were 57 ± 8 μm and 59 ± 14 μm in the maxillary and mandibular arch, respectively, and their reliability was almost perfect. The average errors between IOSb and IOS1c images exhibited an increase, which measured 97 ± 28 μm in the maxillary arch and 95 ± 29 μm in the mandibular arch. These surface deviations between IOSb and IOS1c images were significantly larger in each region as well as entire dentition (P Conclusions The average surface errors of the scans with brackets showed increased values compared with those without brackets. This suggests that orthodontic brackets could affect the trueness of intraoral scan images. Clinical relevance It is necessary for clinicians to consider the effect of brackets on digital impression when using IOS images in orthodontic patients.

Objectives: To determine changes in occlusal curves and dental tipping occurring from mandibular second premolar serial extraction, early extraction of deciduous mandibular second molars with missing second premolars, and late second premolar extraction compared with untreated controls. Materials and Methods: Information was collected from 85 subjects at three time points: T0, prior to serial extraction; T1, after serial extraction and drift prior to orthodontic treatment, and pretreatment for the late premolar extraction patients; and T2, posttreatment. Untreated age- and gender-matched controls were used for comparison. Three occlusal curves were measured on digitized mandibular casts, and dental tipping was assessed using lateral cephalograms. Results: At T0, there were no significant differences among groups. At T1, there was significant steepening of Monson's sphere and the curve of Wilson between early and late extraction and control groups. At T2, the differences in Monson's sphere and the curve of Wilson were fully corrected. At T1, there were significant differences in the tipping of mandibular 6's, 4's, and 3's between the early extraction groups compared with the late extraction and control groups. At T2, these differences in tipping were fully corrected. There were no differences in mandibular incisor tipping between groups at T1 or T2. Conclusions: Serial extraction produced steeper occlusal curves and significant tipping of mandibular first molars, first premolars, and canines after extraction and physiologic drift (T1). Accentuated occlusal curves and tooth tipping were fully corrected following orthodontic treatment (T2). Mandibular incisor position was unchanged by serial or late second premolar extraction.

Objectives: To compare palatal symmetry, dimensions, and molar angulations following early mixed-dentition slow maxillary expansion with parameters in normal controls. Materials and Methods: A total of 30 patients treated with a Haas-type expander for unilateral posterior crossbite with functional shift were compared with 30 controls matched for dental age, gender, and molar relationship. Records were taken before (T1) and after expansion (T2). Palatal width, surface area, volume, and molar angulations were measured on digitized models. Surface area and volume were split in half then divided into anterior, middle, and posterior segments to measure symmetry. Student's t-test was used to assess group differences. Results: Mean intercanine width increased 4.65 mm, and intermolar width increased 4.76 mm. The treated mean surface area increased 127.05 mm2 compared with 10.35 mm2 in controls. The treated palatal volume increased 927.55 mm3 compared with 159.89 mm3 for controls. At T1, the controls showed significant differences in surface area and volume between the anterior palatal segments. At T2, this difference occurred in surface area of middle palatal segments of the treated sample. First permanent molars showed an increased buccal and distal inclination after treatment, opposite to controls. The increase in buccal inclination was greater on the crossbite side. Conclusions: The Haas-type expander results in similar expansion across the canines and first molars. A palate that is symmetrical before expansion may become asymmetric after expansion but only in the middle segment. Changes in individual molar angulation following palatal expansion can be measured without radiation imaging.

(1) Assess the level of available evidence regarding fistula occurrence in cleft lip and palate patients, (2) identify main research areas in the original studies, (3) evaluate the quality of original studies, and (4) summarize the evidence.Two independent researchers searched the Cochrane Database of Systematic Reviews, Medline, Web of Knowledge, Web of Science and EMBASE, the Grey literature, and the reference lists of main references. The level of evidence was assessed based on study design and according to the Hierarchy of Evidence. The quality assessment was done using the adapted Consolidated Standards of Reporting Trials and Strengthening the Reporting of Observational Studies in Epidemiology checklists and a validity scoring system. Main findings were summarized, and fistula rates were compared between early and more recent articles, also between high-quality and low-quality studies.The systematic search and relevance assessment identified a total of 127 sources of evidence. The overall level of evidence was weak because it was dominated by small studies (30 subjects), retrospective cohort studies, and case series. Main research areas were either: (1) focused on surgeries or (2) focused on risk determinants associated with fistula occurrence. Recent reports were of higher quality than the older ones, but the overall quality in the majority of reports was low. Knowledge synthesis demonstrated a wide range of rates for primary fistula (0-78%). No significant difference was found in the fistula rates of older studies compared with more recent studies or among different quality studies. Multiple risk determinants were studied and age at surgery, surgeon's experience, type and severity of cleft were the most frequently examined risk determinants. However, findings concerning different risk determinants and fistula occurrence were not consistent.The research mainly focused on surgeries and fistula-related risk determinants. The available evidence was low level and of poor quality. No consistent pattern between fistula occurrence and any of the risk determinants could be detected. Reported fistula rates did not differ significantly when comparing older studies with more recent studies or when high-quality studies were compared with low-quality studies.

Introduction One factor that can affect treatment outcomes is the treatment provider, and this factor has not been extensively studied. This research aimed to evaluate orthodontic treatment quality, length, and efficiency when 2 orthodontists collaborated on treatment, compared with the treatment provided solely by either orthodontist. Methods A total of 150 consecutively treated subjects were divided into 3 equal groups based on the treating clinician. Patients in group A were treated by orthodontist A, group B by orthodontist B, and group C by both orthodontists in collaboration. The Peer Assessment Rating (PAR), Index of Complexity, Outcome, and Need (ICON), American Board of Orthodontics–Discrepancy Index, and American Board of Orthodontics–Cast and Radiographic Evaluation were used to assess the pretreatment and posttreatment status. Patient age, gender, type of malocclusion, extraction treatment, orthognathic surgery, treatment length, number of visits, and treatment efficiency index were assessed. Results Posttreatment PAR and ICON indices showed excellent results in all 3 groups. American Board of Orthodontics–Cast and Radiographic Evaluation was significantly higher in group C (25.3 points) than in group A (21.5 points) or group B (22.0 points) (P = 0.014). Patients in group A had significantly shorter treatment time (23 months) than those in either group B or C (26 months) (P = 0.011). Patients in group C required more appointments (27 visits) than those in either group A or B (23 and 25 visits, respectively). The treatment efficiency index showed no statistically significant difference among the 3 groups. Conclusions There was no difference in treatment quality among the 3 groups, as assessed by the PAR index and ICON. Jointly treated cases required 2 to 4 more visits and had higher American Board of Orthodontics–Cast and Radiograph Evaluation scores than those treated by either orthodontist. Complex cases required 6 to 7 more months when they were treated collaboratively.

The aim of this study was to determine the prevalence of malocclusion and orthodontic treatment need according to the Index of Complexity, Outcome, and Need (ICON) among schoolchildren of the island community of Haida Gwaii in northwestern British Columbia, Canada. Two elementary and two high schools in Haida Gwaii were approached for census sampling. Out of 535 schoolchildren, 215 (90 boys and 125 girls) agreed to participate (40.2% response) in this cross-sectional epidemiological study. A trained examiner assessed orthodontic treatment need in children employing the ICON score and the ICON complexity grade. The mean age (N = 215) was 12.9 ± 2.8 years. Of the examined schoolchildren, 67% had Aboriginal ancestry (at least one Aboriginal parent). The mean ICON score (N = 215) was 43.5 ± 26.2. There were no statistically significant differences in ICON scores for gender (t test, p = 0.207), ethnicity (t tests: paternal ethnicity, p = 0.886 and maternal ethnicity, p = 0.389), or school (ANOVA with post hoc Bonferroni adjustment, p = 0.317). Overall, 43.7% of the surveyed Haida Gwaii adolescents needed orthodontic treatment (ICON > 43). Based on the ICON complexity grade, 31% of the schoolchildren had moderate to very difficult malocclusions; therefore, specialty orthodontic services are recommended in this remote community.

Objective: To examine the time trends and determinants of palatal fistula in children with different types of cleft at British Columbia's Children's Hospital between 1995 and 2012. Methods: A total of 558 medical charts of nonsyndromic patients with cleft lip and palate were eligible for the chart review. The occurrence of primary palatal fistula was assessed at any time throughout the patient's total observation period. Three types of clefts were recorded: unilateral cleft lip and palate (ULCLP), bilateral cleft lip and palate (BLCLP), and isolated cleft palate (ICP). Cleft severity, time period of treatment, type of surgery and surgeon's experience were tested as determinants. Results: Of all 558 patients, 228 had ULCLP, 226 had ICP, and 104 had BLCLP. The combined postoperative palatal fistula rate was 28%. The significant differences in fistula rates related to type of cleft (patients with BLCLP had the highest fistula rates), time period (rates were higher in earlier years than in later years), type of surgery (highest rates were for two-flap palatoplasty), and surgeons with less experience. Conclusions: Almost one quarter of the patients, developed fistula, and fistula incidence declined after 2009. The higher fistula rates were determined by cleft severity, time period of treatment, type of surgery, and surgeon's experience.

Cyanobacteria are present in many drinking water reservoirs in Taiwan, and some of them may produce off-flavour compounds and natural toxins. To investigate the correlation among two groups of cyanobacterial metabolites, microcystins and 2-methylisoborneol (2-MIB), and other environmental parameters, approximately 22 water quality and meteorological parameters were monitored for two source waters (Moo-Tan and Tseng-Wen reservoirs) in south Taiwan from August 2003 to April 2005. Monitoring results showed that the two groups of cyanobacterial metabolites were present in the source waters. Concentrations of 2–30 ng/L of 2-MIB was observed for the two reservoirs, while that of the total concentrations of the five microcystin congeners measured were between 30 and 340 ng/L. The concentration of both 2-MIB and microcystins showed higher concentrations in warmer seasons. A stepwise regression technique was employed to correlate 2-MIB and microcystins concentrations with all the corresponding water quality and meteorological parameters. Correlations among 2-MIB concentration, microcystin concentration, water temperature and air temperature were found in the water samples collected from both reservoirs. The correlations may provide a simple means for the water utility to anticipate the two groups of cyanobacterial metabolites in the two source waters.

Cyanobacteria are present in many drinking water reservoirs in the world, and some of them may produce microcystins, anatoxin-a and other natural toxins: In this study, two groups of algal toxins: microcystins and anatoxin-a, and associated toxin producers were investigated. Water samples from nine major drinking water reservoirs and seven associated water purification plants were collected. An HPLC and an LC/MS were employed to detect the concentrations of five microcystins (microcystins-LR, RR, YR, LW, LF) and anatoxin-a. Molecular biotechnology methods were used to sequence Microcystis sp. gene from the cyanobacteria bloom from two of the reservoirs. Monitoring results suggested that microcystins were present in all the drinking water reservoirs studied, and some of them had concentration higher than the WHO guideline of microcystins-LR (1 μg/L). Unlike microcystins, anatoxin-a was only found in four reservoirs, mostly in King-Men island. After comparing the DNA sequence with existing cyanobacteria reference database, Microcystis aeruginosa and other Microcystis sp. were confirmed present in the two reservoirs tested.

The purpose of this study was to assess in vitro bone nodule formation by cells exposed to a range of microstrain, at a sub-optimal oscillation frequency for bone formation. Fetal rat calvarial cells experienced a Flexercell regimen within either FLEX I (deformable) or FLEX II (non-deformable) substrates. Cells in FLEX I plates were exposed to growth medium only; those in FLEX II plates were exposed to either growth medium only, or growth medium + 10(-7) M IGF-1. Cell numbers were assessed from 1 to 6 days. Other cells were exposed to the Flexercell regimen (-2 kPa, 0.05 Hz) for 1-3 (Group 1), 3-6 (Group 2), 1-9 (Group 3) or 10-15 (Group 4) days and were maintained, at other times, under standard conditions. After 21 days, nodules were counted within each well and within the compression,999, 1000-4900, 5000-9999, 10,000-14,999 and 15,000-25,000 microstrain regions of the FLEX I membrane. Cyclic deformation inhibited cell numbers from 1 to 6 days, compared to control or IGF-1 groups (P0.001). The number of nodules in Groups 2 and 4 were greater than Groups 1 or 3 (P0.001), but not different from control or IGF-1 groups. Compression or tensile microstrain significantly affected nodule formation in all groups, with Group 4 producing more nodules than other groups in most microstrain regions. Thus, the number of bone nodules produced by osteogenic cell cultures exposed to cyclic deformation was significantly affected by the timing of initiation and the characteristics and magnitude of the deformation regimen.

Introduction Variations in treatment times for serial extraction and late premolar extraction patients may be due to differences in the time needed to flatten the occlusal curves. In this study, we compared tooth tipping and occlusal curves in patients treated by serial extractions or late premolar extractions with untreated controls. Methods Mandibular dental casts and cephalometric radiographs were collected from 90 subjects (30 Class I control subjects, 30 patients with serial extractions, and 30 with late premolar extractions) at 3 time points: T0, baseline for the controls and serial extraction patients; T1, after natural drift and preorthodontics for the controls and the serial extraction patients, and pretreatment for the late premolar extraction patients; and T2, after comprehensive orthodontic treatment for the serial extraction and the late premolar extraction groups. The long axes of the central incisor, canine, and first molar to the palatal plane were measured on digitized headfilms to determine the direction and the amount of tipping between the time points. Three occlusal curves were measured by sphere fitting cusp-tip landmarks on digitized mandibular casts. Results From T0 to T1, incisors and canines in the patients with serial extractions tipped distally. Molars at T1 in the patients with serial extractions were tipped forward more than in the late premolar extraction patients and the controls. From T1 to T2, canines and molars in the patients with serial extractions were uprighted. Conclusions Serial extractions produce steeper occlusal curves and distal tipping of the incisors and canines after drift (T1). Posttreatment (T2) occlusal curves in the patients with serial extractions are steeper than in the late premolar extraction patients and controls (except for the curve of Spee). After the serial extractions, orthodontic treatment included incisor and canine proclination, with molar uprighting and occlusal curve flattening.

Sodium acetate reportedly promotes bone atrophy by inducing resorption and inhibiting osteoprogenitor-cell proliferation, but little is known about its effects on bone-matrix deposition and mineralization by a population containing osteoprogenitor cells. The objective here was to assess the effects of 1-20 mM sodium acetate on the proliferation and differentiation of these cells and their resultant bone-nodule formation and mineralization in an in vitro assay. Exposure to 10 mM sodium acetate had no effect on cellular proliferation but significantly increased the production and mineralization of bone nodules (p0.01), suggesting that it affected osteoprogenitor differentiation and subsequent metabolism. However, 10 mM acetate did not increase net bone mass. Dilutions of 1-5 and 20 mM inhibited cellular proliferation and resultant bone-nodule formation and mineralization, significantly reducing the percentage bone area as compared to controls (p0.001). These data suggest that 1-5 and 20 mM sodium acetate significantly inhibit bone deposition, whereas 10 mM has no effects, which could contribute to iatrogenic metabolic bone disease in patients receiving either renal dialysis or total parenteral nutrition.

Erythropoietic protoporphyria (EPP) is an inherited blood disorder in which formation of the heme group of hemoglobin is defective. Specifically, a deficiency of the enzyme ferrochelatase leads to the accumulation of protoporphyrin, resulting in often painful photosensitivity of the skin and tissues. The prevalence of EPP is estimated at 1:75,000 to 1:200,000. Photosensitivity is exhibited upon exposure to light with specific wavelengths through the creation of reactive oxygen products (oxidants), activation of the complement system, and mast cell degranulation. The aim of this article is to report the orthodontic treatment of an 11-year-old boy with EPP, a Class III skeletal relationship, and an anterior crossbite. Orthodontic treatment established normal overbite and overjet. Short-term periodontal and dental tissue responses to treatment were noted. Extra care was needed when collecting photographic and radiographic records for this patient and during some treatment procedures to avoid causing a photosensitive reaction of the skin or oral mucosa.

The mechanism by which compressive mechanical stress affects glycosaminoglycan synthesis in the articular disk was investigated with a modified organ culture technique. Forty-eight male Sprague-Dawley rats were divided into three experimental groups and one control group of 12 animals each, aged 7 and 9 weeks. The experimental groups followed different regimens of stress applied for 25%, 75%, or 100% of the time during the total test period of 24 hours. Articular disks were stressed with flexible bottomed dishes (Flex I dishes, Flexcell Corp., McKeesport, Pa.) using the Flexercell Strain Unit (Flexcell Corp., McKeesport, Pa.) and incubated with [3H]-glucosamine for 24 hours. Samples were then collected, digested with Pronase-E, and after precipitation with cetylpyridinium chloride (CPC) and ethanol, the different glycosaminoglycans (GAGs) were separated by using cellulose acetate electrophoresis. The significant GAG types with stress were chondroitin6sulfate (C6S), hyaluronic acid (HA), and dermatan sulfate (DS). There was no significant relationship in the experimental groups between age and regimen of stress applied in either age. Higher stress regimens showed significantly higher proportions of C6S when compared with the controls, whereas HA appeared to decrease slightly and DS was not affected. Since C6S is the major component of hyaline cartilage, the results of this study suggest that compressive forces in the articular disk may stimulate the development of more cartilagenous-like properties with respect to GAG content.

Newly synthesized collagen and glycosaminoglycans (GAG) were studied in the temporomandibular discs of male Sprague-Dawley rats of 3-13 weeks of age. Each age group had eight animals and [14C]glycine or [3H]glucosamine were used to determine the proportion of newly synthesized type III to type I collagens or the proportion of different types of newly synthesized GAGs during 4 h of labelling in organ culture. Separation of newly synthesized collagen bands from rat disc by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed a peak in type III at the ages of 7 and 8 weeks. Type III collagen synthesis and the rate of mandibular growth were strongly related through all ages studied. GAG chains were separated by cellulose-acetate electrophoresis. Calculation of disintegrations/min per mg of wet disc tissue for each GAG peak showed that hyaluronic acid (HA), chondroitin-6-sulphate and keratan sulphate/chondroitin-4-sulphate (KS/C4S) were the predominant molecules synthesized in the disc. There was also a steady increase in newly synthesized HA and C6S synthesis up to 6 and 7 weeks respectively. Proportions of newly synthesized C4S/KS, HA and C6S were significantly higher than those of other GAGs with respect to ageing. From these observations it appears that the articular disc shows more of the characteristics of cartilage, as evidenced by the increased amounts of C6S and KS/C4S during the mandibular growth spurt at the ages of 6 and 7 weeks, similar to that of type III collagen. There were also increased amounts of HA, suggesting that during 5-7 weeks of age the rat disc is undergoing more active remodelling. This study provides baseline data for further analysis of the effects of mechanical loading and trauma on articular disc responses.

Vascular changes in the periodontal ligament after release of orthodontic force and their possible contribution to relapse of relocated teeth are poorly understood. This study documented the periodontal vascular changes after 2 weeks of tooth movement and during a 3-week period after release of orthodontic force. This study is the first comprehensive quantitative description of these events. Changes in blood vessel number and density were correlated with the direction of tooth movement (initially mesial in response to force but later distal because of relapse). Application and removal of orthodontic force produced significant changes in blood vessel number and density, which were not related to changes in tissue volume. The vascular changes were dependent on the site of evaluation and the size of the blood vessel. The periodontal vascular distribution and density can be summarized as follows: (1) increased after application of orthodontic force, (2) transient decrease subsequent to removal of force, (3) transient increase during reactivated distal drift, and (4) normalization. Normalization was achieved during an interval equivalent to the duration of orthodontic force, suggesting that the vasculature could modulate interstitial tissue pressures, resulting in relapse of relocated teeth. The role of the periodontal vasculature in alveolar remodeling and in modifying interstitial tissue fluid pressures coincident to human tooth movement requires further study.

Mechanical stimulation of the skeleton alters the metabolism of bone cells, but the effects of mechanical strain on the cytoskeleton of osteoblasts are poorly understood. While changes in the distribution of the cytoskeleton in mechanically strained cells have been reported, little is known about the pathways by which these changes are transduced into cell functions. Human osteosarcoma (HOS) TE-85 cells were cultured in Dubelcco's modified Eagle's medium/F-12 and grown to confluency in Flexercell type I dishes in a humidified incubator with 5% CO2 and 95% air. Intermittent strain (3 cycles/min) was applied to the cells for periods of 15 and 30 min, 2, 4 and 24 h, and 3, 5, 7, 10, 14, 20 and 28 days. Unstrained cells were used as controls. The distribution of beta 1 integrin was studied immunocytochemically. Total RNA was isolated at every period of time and Northern blots were used to study the effects of strain on the levels of beta 1-integrin expression. The results indicated that mechanical strain increased the synthesis of beta 1 integrin. Northern blots showed that beta 1 mRNA expression was increased significantly (p < 0.005) at 30 min and 3 days of strain application. Strain also affected beta 1 distribution markedly in 24-h cultures. The response of HOS cells to mechanical strain demonstrates that the cytoskeleton of the osteoblast adapts to strain through the stimulation of specific cytoskeletal and receptor proteins. These results suggest a pathway through which mechanical strain is transmitted to the osteoblastic-like cells.

Second-messenger systems have been implicated to transmit mechanical stimulation into cellular signals; however, there is no information on how mechanical stimulation is affected by such systemic factors as parathyroid hormone (PTH). Regulation of adenylyl cyclase and phosphatidylinositol pathways in rat dentoalveolar bone cells by mechanical strain and PTH was investigated. Two different cell populations were isolated after sequential enzyme digestions from dentoalveolar bone (group I and group II) to study potential differences in response. Mechanical strain was applied with 20 kPa of vacuum intermittently at 0.05 Hz for periods of 0.5, 1, 5, 10, and 30 minutes and 1, 3, and 7 days using the Flexercell system. Levels of cAMP, measured by RIA, and levels of inositol 1,4,5-triphosphate (IP3) and protein kinase C activity (PKC), measured by assay systems, increased with mechanical strain. When PTH was added to the cells, there was a significant increase in levels of all the intracellular signals, which appeared to potentiate the response to mechanical strain. IP3 levels (0.5 minute) peaked before those of PKC activity (5 minutes), which in turn peaked before those of cAMP (10 minutes). Group II cells showed higher levels of cAMP and IP3 than the group I cells. This suggests that the former may ultimately play the predominant roles in skeletal remodeling in response to strain. Immunolocalization of the cytoskeleton proteins vimentin and alpha-actinin, focal contact protein vinculin, and PKC showed a marked difference between strained and nonstrained cells. However, the addition of PTH did not cause any significant effect in cytoskeleton reorganization. Staining of PKC and vimentin, alpha-actinin, and vinculin suggests that PKC participates actively in the transduction of mechanical signals to the cell through focal adhesions and the cytoskeleton, although only PKC seemed to change with short time periods of strain. In conclusion, dentoalveolar osteoblasts responded to mechanical strain initially through increases in levels of IP3, PKC activity, and later cAMP, and this response was potentiated when PTH was applied together with mechanical strain.