A resident about to graduate from one of the seventy accredited orthodontic programs in the US and Canada is facing a very different scenario than in previous years due to three factors: the current economic climate, the cost of attending a program and increased student debt. The AAO website provides an online document titled Accredited Schools which in 2003 I exported to Excel and analyzed the results. I repeated the exercise with the latest version of this document and will present some conclusions which are dependent upon the AAO document being up to date and accurate. I have also used
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Original Articles
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DOI: 10.2319/021611-114.1
To quantify remodeling in the bone surrounding fully erupted primary teeth and to compare bone remodeling in the primary and permanent dentitions. Two bone sections were obtained bilaterally from the maxilla and mandible of the primary molar region of approximately 5-month-old male beagle dogs. Histomorphometric methods were used to estimate the osteonal remodeling in the alveolar and basal regions of the tooth supporting bone. The following variables were calculated: mineral apposition rate (MAR, µm/d), mineralizing surface/bone surface (MS/BS, %), bone formation rate (BFR, %/y), and erosion surface/bone surface (ES/BS, %). Comparisons were made between jaws (maxilla vs mandible) and bone types (alveolar vs basal), and data analyzed by analysis of variance (ANOVA) and Tukey-Kramer tests. Remodeling (BFR) surrounding primary teeth was compared to existing data from bone surrounding permanent teeth. The mean and standard deviation BFR values (%/y) were as follows: mandibular alveolar, 44.10 (±26.89); maxillary alveolar, 3.54 (±3.57); mandibular basal, 22.65 (±14.65); and maxillary basal, 12.33 (±7.11). The mandibular BFR was significantly (P < .05) higher than the maxillary bone. The BFR of the alveolar bone of primary teeth was not significantly (P = .48) different from the alveolar bone supporting permanent teeth. The remodeling rate of alveolar bone in skeletally immature dogs was greater in the mandible than in the maxilla and remained unaltered between primary and permanent dentitions.Abstract
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DOI: 10.2319/021211-102.1
(1) To identify any differences in the accuracy of the prediction of the summed widths of unerupted permanent canines and premolars for males vs females and, if differences are identified, (2) to examine the sex differences in the best combination of independent variables and (3) to evaluate the practical accuracy using our models for both sexes, respectively. Records for 200 orthodontic patients (100 males and 100 females) with discernible tooth crowding in the permanent dentition were selected. Mesiodistal tooth crown widths, dental arch widths, and basal arch lengths were measured. Predicted sum widths of permanent canines and premolars in both dental arches were calculated using stepwise regression analysis. Among male subjects, the best combinations of independent variables were the widths of the upper central and lateral incisors (U1, U2) and the first molar (U6) for the maxilla (R2 = 0.615) and the mandible, lower central and lateral incisors (L1, L2), and the first molar (L6) (R2 = 0.685), whereas in females, the best combinations for prediction were found to be U1, U2, U6, and the maxillary arch width for the maxilla (R2 = 0.429) and L1, L2, L6, and the basal arch length for the mandible (R2 = 0.426). Correlation coefficients between each independent and dependent variable in the female subject group were found to be weaker than those for the male subject group. We found the sex differences in the accuracy of prediction and the best combination of independent variables for predicting the summed widths of unerupted canines and premolars. These new models should be clinically useful, providing highly accurate prediction.Abstract
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DOI: 10.2319/033011-229.1
The objective of this prospective controlled study was to assess the outcomes of two-phase treatment of deepbite patients revaluated at the end of circumpubertal growth, 1 year after the end of a phase-2 treatment. A sample of 58 subjects with deepbite (mean age 9.7 years, overbite greater than 4.5 mm) was treated consecutively with a two-phase protocol. Lateral cephalograms were taken before treatment (T1), at the completion of phase 1 (T2), and 1 year after the completion of phase 2 with fixed appliances (T3, mean age 15.8 years). The T1-T2, T2-T3, and T1-T3 changes were compared with those of the 29 subjects (mean age at T1 = 9.1 years) with untreated deepbite (t-tests for independent samples). Prevalence rates for improved overbite during the T1-T3 interval and for corrected overbite at T3 were contrasted in the treated vs untreated groups (z tests on proportions). Overbite was reduced by 1.9 mm in the treated group as a result of overall treatment; this group also displayed a significant reduction in the interincisal angulation (−6.6°) due to a significant proclination of upper incisors (4.1°) and a significant increase in the projection of the lower incisors (2.0 mm). The average amount of deepbite correction 1 year into retention was modest, and it was mainly due to a significant proclination of the incisors. The prevalence rate of subjects with a corrected overbite in the treated sample at T3 (74%) was not significantly different from that of the untreated sample (52%).Abstract
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DOI: 10.2319/012011-40.1
To better understand the mechanics of bracket/archwire interaction through analysis of force and couple distribution along the maxillary arch. An orthodontic simulator was utilized to study high canine malocclusion. Force/couple distributions, referenced to the center of resistance (CR) of each tooth, produced by passive ligation brackets and round wire were measured. Tests were repeated for 12 bracket sets with 12 wires per set. Propagation of the force/couple systems around the arch was minimal. Binding was observed only on the teeth adjacent to the displaced canine. For most of the teeth, reduced resistance to sliding of the passive ligation bracket yielded minimal tangential and normal forces at the bracket and contributed to lower moments at CR. Some potential mechanical advantages of passive ligation systems are suggested for the case studied. In particular, limited propagation around the arch reduces the occurrence of unwanted force/couple systems.Abstract
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DOI: 10.2319/012011-41.1
To better understand the mechanics of bracket/archwire interaction through analysis of force and couple distribution along the maxillary arch using elastic ligation and to compare these results with passive ligation. An orthodontic simulator was used to study a high canine malocclusion. Force and couple distributions produced by elastic ligation and round wire were measured. Forces and couples were referenced to the center of resistance of each tooth. Tests were repeated for 12 bracket sets with 12 wires per set. Data were compared with those derived from similar tests for passive ligation. Propagation of the force/couple systems around the arch using elastic ligation was extensive. Elastic ligation produced significantly more resistance to sliding, contributing to higher forces and couples at the center of resistance than were observed for passive ligation. The results of this study suggest some potential mechanical advantages of passive over elastic ligation. In particular, limited propagation around the arch in passive ligation reduces the occurrence of unwanted force/couple systems compared with elastic ligation. These advantages may not transfer to a clinical setting because of the conditions of the tests; additional testing would be required to determine whether these advantages can be generalized.Abstract
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DOI: 10.2319/022011-122.1
To test the hypotheses that (1) there is no difference in mandibular asymmetry between the crossbite and normal side in a unilateral crossbite group (UCG) and between the right and left sides in a bilateral crossbite group (BCG) and a control group (CG); and (2) there is no significant difference in mandibular asymmetry among crossbite groups and control group. The cone-beam computed tomography scans of three groups were studied: (1) 15 patients (6 male, 9 female; mean age: 13.51 ± 2.03 years) with unilateral posterior crossbite; (2) 15 patients (8 male, 7 female; mean age: 13.36 ± 2.12 years) with bilateral posterior crossbite; and (3) 15 patients (8 male, 7 female; mean age: 13.46 ± 1.53 years) as a control group. Fourteen parameters (eight linear, three surface, and three volumetric) were measured. Side comparisons were analyzed with paired samples t-test, and for the intergroup comparison, analysis of variance (ANOVA) and Tukey tests were used at the P < .05 level. According to side comparisons, no statistically significant difference was found in the UCG. There were statistically significant differences in hemimandibular (P = .008) and ramal (P = .004) volumes for the BCG and in ramal height (P = .024) and body length (P = .021) for the CG. Intergroup comparisons revealed significant differences in hemimandibular (P = .002) and body volume (P < .001) for the normal side of the UCG and left sides of the other groups, and in angular unit length (P = .025) and condylar width (P = .007) for the crossbite side of the UCG and the right sides of the other groups. Contrary to UCG, CG and BCG were found to have side-specific asymmetry. Skeletal components of the mandible have significant asymmetry among the crossbite groups and the CG.Abstract
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DOI: 10.2319/122810-749.1
To examine whether intermittent posterior condylar displacement causes changes in cancellous bone in the mandibular condyle during the growth period. Sixteen 5-week-old male Wistar rats were divided into experimental and control groups. In the experimental group, an appliance was attached to the maxillary incisors to induce posterior displacement of the condyles in the occluded condition. Untreated rats served as the control group. Animals were sacrificed at 14 days, and the condyles were removed to analyze the three-dimensional cancellous bone structure by microcomputed tomography (micro-CT). Serial sagittal paraffin sections of the condyles were used for hematoxylin and eosin staining to investigate histomorphological changes and for tartrate-resistant acid phosphatase (TRAP) staining to identify osteoclastic cells. Micro-CT analysis showed that in the experimental group, the bone volume fraction and the degree of anisotropy were significantly decreased compared with those in the control group in the anterior region of the condyle. Moreover, the number of TRAP-positive cells was significantly greater in the same region in the experimental group than in the control group. Intermittent posterior displacement of the mandible can cause region-specific changes in the profile and microarchitecture of the condylar cancellous bone.Abstract
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DOI: 10.2319/030211-150.1
To analyze the effects of single-jaw surgery (mandible or maxilla only) vs bimaxillary surgery on final peer assessment rating (PAR) score outcome and overall treatment duration. Treatment records of 63 consecutively treated orthognathic patients were assessed; 41 underwent bimaxillary procedures, and the remainder single-jaw procedures. All treatment was undertaken at Kent and Canterbury Hospital in the United Kingdom. Demographic characteristics and clinical parameters, including treatment duration, number of visits required, initial and final PAR scores, and number of extractions undertaken, were recorded. The mean treatment time was 30.6 months; treatment time was shortest in the maxillary procedure only group. The mean reduction in percentage PAR score was 77%, with an average final score of 9. Linear regression analysis confirmed that procedure type had no influence on final PAR score (P = .62) or on overall treatment duration after adjustment for extractions and initial PAR score as confounders (P = .47). No significant difference was noted in treatment duration or in occlusal outcome between single- and double-jaw surgeries.Abstract
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DOI: 10.2319/112210-681.1
To examine and compare the maxillofacial characteristics affecting chin deviation three-dimensionally in facial asymmetry patients with mandibular retrusion and mandibular prognathism. Maxillofacial computed tomography (CT) scan data were obtained from 48 orthognathic surgery patients (24 cases of mandibular retrusion and 24 cases of mandibular prognathism) with facial asymmetry. Although chin deviation was assessed on the basis of the ANS-to-menton line on frontal cephalograms, its contributing factors were evaluated on three-dimensional CT images. Maxillary height, ramus length, frontal ramal inclination, lateral ramal inclination, mandibular body length, and body height were defined on each side, and right-left differences were calculated and analyzed. In an assessment of chin deviation, subjects in this study showed predominantly left side deviation regardless of the group, and the degree of menton deviation did not reveal significant differences between groups. In a comparison of right-left differences in contributing factors, all values were noted to be greater in the retrusion group, except for body height, which showed no difference between chin-deviated and contralateral sides. In particular, ramus length presented a statistically significant difference between the two groups. Based on the same degree of chin deviation in mandibular prognathism and retrusion in this study, results of right-left differences in contributing factors indicate that chin deviations are expressed easily in mandibular prognathism, whereas they occur only with significant right-left differences in relevant maxillofacial structures in individuals with mandibular retrusion.Abstract
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DOI: 10.2319/120810-711.1
To quantify in vivo changes in miniscrew implant (MSI) stability over time using resonance frequency analysis, and to determine if pilot holes and placement sites affect changes in MSI stability. Twenty-two self-tapping MSIs (1.6 mm wide and 9 mm long) were placed in the maxillae of 2 adult beagle dogs (20 months old). The Osstell Mentor was used to measure the implant stability quotient (ISQ) weekly for 8 weeks. A split-mouth design was used to evaluate the effects of 1.1-mm wide, 3-mm deep pilot holes. The MSIs that failed showed significantly (P < .05) greater decreases in ISQ values during the first 3 weeks than the MSIs that remained stable. All of the MSIs that failed (41%) had been placed in nonkeratinized tissue. MSIs that remained stable throughout the study also showed significant decreases in ISQ values during the first 3 weeks, followed by increases during the fourth and fifth weeks. Changes in ISQ values of MSIs inserted into bone with and without pilot holes were comparable (P > .05). Stability of unloaded MSIs decreased during the first 3 weeks and increased thereafter. Although the effects of pilot holes on stability could not be confirmed, placement of MSIs into nonkeratinized tissue negatively affected their stability and increased the likelihood of failures.Abstract
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DOI: 10.2319/031011-176.1
To assess the mechanical stability of a newly revised orthodontic mini-implant design (N2) compared with a design introduced in Part 1 of the study (N1) and the most widely-used commercially-available design (CA). To evaluate the mean buccal bone thickness of maxillary and mandibular posterior teeth using cone-beam computed tomography (CBCT). From the CBCT scans of 20 patients, six tomographic cross-sections were generated for each tooth. Buccal bone thickness was measured from the most convex point on the bone to the root surface. CA (1.5 mm in diameter and 6 mm in length), N1, and N2 (shorter and narrower than N1) were inserted in simulated bone with cortical and trabecular bone layers. Mechanical stability was compared in vitro through torque and lateral displacement tests. The bone thickness ranged from 2.26 to 3.88 mm. Maximum insertion torque was decreased significantly in N2 compared to N1. However, force levels for all displacement distances and torque ratio were the highest in N2, followed by N1 and CA (α = .05). Both torque and lateral displacement tests highlighted the enhanced stability of N2 compared with CA. Design revisions to N1 effectively mitigated N1's high insertion torque and thus potentially reduced microdamage to the surrounding bone. The N2 design is promising as evidenced by enhanced stability and high mechanical efficiency. Moreover, N2 is not limited to placement in interradicular spaces and has the capacity to be placed in the buccal bone superficial to the root surface with diminished risk of endangering nearby anatomic structures during placement and treatment.Abstract
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DOI: 10.2319/012311-47.1
To evaluate the success rate of Bollard miniplate anchorage for bone anchored maxillary protraction (BAMP). Twenty-five consecutive patients (mean age, 12.0 ± 1.2 years; range, 8.7–14.8 years) with maxillary hypoplasia without congenital or acquired deformation were included in this study. A total of 100 Bollard modified miniplates were placed by the same surgeon. Ninety-nine miniplates were inserted under general anesthesia, and one was placed under local anesthesia because of initially soft bone conditions. Loading of the miniplates with 150 g elastics was initiated at 17.5 ± 6.9 days (range, 11–38 days) after surgery. Mean follow-up was provided at 20.8 ± 11.1 months (range, 6.5–46.2 months). The overall success rate of miniplate anchorage in terms of stability was 97%. During orthodontic loading, five miniplates showed signs of mobility. After interruption of loading over 2 months, two miniplates became stable again. However, a total of three miniplates needed to be removed and were successfully replaced under local anesthesia after a mean healing period of 3 months. Skeletal anchorage by means of Bollard modified miniplates is effective for BAMP. Success depends on proper presurgical patient counseling, minimal invasive surgery, good postsurgical instructions, and orthodontic follow-up.Abstract
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DOI: 10.2319/120710-708.1
To measure ion release from four sol-gel bioactive glass–containing orthodontic resin bonding agents (BAG-Bonds) following immersion into simulated body fluid (SBF) at pH values of 4 and 7. Four BAG-Bonds, two containing fluoride, were developed. Prepared in our laboratory, the BAG-Bonds were composed of a mixture of resin monomers and bioactive glasses (BAGs). Workability of the final BAG-Bonds determined the amount of filler added to each, and this varied according to BAG composition. Commercially available Transbond-XT was used as the control. Three disks (10 mm × 2 mm) of each material were individually suspended in 3.5 mL of SBF at pH 4 and pH 7. SBF was analyzed to measure pH and ions released at 1 hour, 10 hours, and 100 hours. Calcium was measured by atomic absorption analysis, phosphate by ultraviolet visible spectrometry, and fluoride by an ion-specific electrode. The data were compared using a three-way analysis of variance, with P ≤ .05. Significant differences in calcium and phosphate ion release were found between the four BAG-Bonds and the control at multiple time points. Significant changes in pH were also found. There was no measureable release of fluoride from any of the materials. The BAG-Bonds showed the capacity for buffering acidic oral environments and significant release of calcium ions into their surrounding environment, and they hold the potential to be biomimetic bonding agents that may reduce white spot lesion formation.Abstract
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DOI: 10.2319/121710-727.1
To evaluate and compare the effects of circumferential supracrestal fiberotomy in vivo (using diode, CO2, and Er∶YAG lasers) on the morphology and chemical composition of the root surface. Forty healthy premolar teeth, intended for extraction for orthodontic reasons, were used in this study. Root surfaces were treated using different laser methods, as follows: (1) control; (2) Er∶YAG laser (2.94 µm, 100 mJ, 10 Hz); (3) diode laser (808 nm, 1.2 W, continuous wave); and (4) CO2 laser (10.6 µm, 3 W, continuous wave). Subsequently, the teeth were removed and subjected to scanning electron microscopic (SEM) examination and energy dispersive x-ray (EDX) spectrometric analysis. SEM analysis indicated that no thermal changes, including melting or carbonization, were observed following the lasing procedures. EDX analysis showed that the laser procedures resulted in similar mineral contents (weight % of calcium and phosphate) as compared to those in the control group. Based on these findings, we concluded that laser-aided procedures, when used at appropriate laser settings, preserve the original morphology and chemical composition of cementum.Abstract
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DOI: 10.2319/021111-101.1
To assess the antiadherent and antibacterial properties of surface modified stainless steel orthodontic brackets with photocatalytic titanium oxide (TiO2) against Lactobacillus acidophilus. This study was done on 120 specimens of stainless steel preadjusted edgewise appliance (PEA) orthodontic brackets. The specimens were divided into four test groups. Each group consisted of 30 specimens. Groups containing uncoated brackets acted as a control group for their respective experimental group containing coated brackets. Surface modification of brackets was carried out by the radiofrequency (RF) magnetron sputtering method with photocatalytic TiO2. Brackets then were subjected to microbiological tests for assessment of the antiadherent and antibacterial properties of photocatalytic TiO2 coating against L acidophilus. Orthodontic brackets coated with photocatalytic TiO2 showed an antiadherent effect against L acidophilus compared with uncoated brackets. The bacterial mass that was bound to the TiO2-coated brackets was less when compared with the uncoated brackets. Furthermore, TiO2-coated brackets had a bactericidal effect on L acidophilus, which causes dental caries. Surface modification of orthodontic brackets with photocatalytic TiO2 can be used to prevent the accumulation of dental plaque and the development of dental caries during orthodontic treatment.Abstract
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DOI: 10.2319/122810-751.1
To elucidate some of the parameters determining the frictional behavior of passive, active, and interactive self-ligating brackets during sliding mechanics. A custom jig mimicking the three-dimensional tooth movements that occur during sliding mechanics and an Instron testing machine were used to determine the resistance to sliding of six different self-ligating brackets (SPEED, In-Ovation C, CarrièreSLB, ClaritySL, SmartClip, VisionLP). Each bracket was tested on three rectangular stainless steel wires: 0.017 × 0.022 inch, 0.017 × 0.025 inch, and 0.019 × 0.025 inch. A two-way balanced analysis of variance was used for statistical analysis. The four passive self-ligating brackets (CarrièreSLB, ClaritySL, SmartClip, VisionLP) displayed significantly lower frictional resistance (P < .001) than the remaining brackets, which featured an active (SPEED) or interactive (In-Ovation C) clip. The SPEED bracket consistently demonstrated the highest resistance to sliding. The mode of self-ligation appears to be the primary variable in determining the frictional behavior of orthodontic brackets undergoing sliding mechanics. Passive self-ligating brackets demonstrated significantly lower frictional resistance to sliding. With regard to the resistance of active self-ligating brackets, the depth (buccolingual thickness) of the wire had a more significant influence than its height.Abstract
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DOI: 10.2319/030711-165.1
To determine the relationship of E-space preservation with lingual holding arches to mandibular permanent second molar impaction. Two hundred consecutively treated patients undergoing nonextraction treatment for incisor crowding were entered into the study. Lower incisor crowding was assessed by the Little Irregularity Index. Treatment involved E-space preservation via a passive lingual arch placed prior to exfoliation of the second primary molar. Panoramic and cephalometric radiographs were analyzed for any significant relationship of mandibular permanent second molar impaction relative to molar angulation, spacing, growth pattern, and skeletal relationships. Twenty-nine patients had at least one impacted second molar (14.5%). Of a possible 400 mandibular second molars, 34 were determined to be impacted (8.5%). Only the mandibular first molar–second molar angulation was found to be significant (P < .001). Pretreatment intermolar angulation of 24 degrees had a positive predictive value of 1. Impaction of permanent second mandibular molars in patients undergoing nonextraction via E-space preservation with a passive lingual arch is 10 to 20 times more prevalent than that observed in the general population. Risk of impaction is best predicted by the pretreatment intermolar angulation between first and second permanent mandibular molars.Abstract
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DOI: 10.2319/022211-132.1
To assess the frequency and type of upper bonded retainer failure and to identify possible predisposing factors. The records of 466 consecutive patients with upper bonded retainers were analyzed retrospectively with respect to retainer failures and failure type as well as timing of failure, differences among operators, and the number of defects of the multibracket appliances (MB) prior to the retention period. A total of 58.2% of all patients experienced retainer failures. The average failure odds were 1.26 failures per retainer. The odds were highest for 3-3 retainers (1.37) and lowest for the 1-1 retainer (0.54). The detachment and total loss rates were significantly influenced by operator experience—both rates were lower for experienced practitioners. Total retainer losses occurred more frequently in case of previous MB defects, while retainer fractures were seen more frequently when the retainer included the canines. Upper bonded retainer failures are a frequent problem during the retention period (58.2% of patients). Less operator experience correlated with higher failure rates. An increased number of total retainer losses must also be expected with a decreasing number of bonding sites and in cases involving previous MB defects.Abstract
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DOI: 10.2319/013111-62.1
To determine the forces and moments delivered to a maxillary central incisor during rotation with aligners when a simulated occlusal force generated during swallowing acts on the appliance. Five identical appliances were manufactured from four different starting materials (Erkodur 0.8 mm and 1.0 mm; Biolon 0.75 mm and 1.0 mm). An upper central incisor fixed in a measuring device was rotated around its central axis in 0.5-degree steps up to ±10 degrees with the appliance fixed in place. An occlusal force of 30 N generated during swallowing was simulated with a weight positioned on the appliance. For statistical analysis, the moments Tz (rotation) and forces Fz (intrusion) at a deflection of ±0.34 mm to the incisor edge (±5 degrees rotation) were tested. Means and standard deviations for Tz and median and 25% and 75% quartiles for Fz were calculated. An analysis of variance was performed. The simulated occlusal force increased the measured intrusive force Fz (maximum with a weight, −3.7 N [−3.7, −2.4]; minimum without a weight, −1.3 N [−1.4, −1.1]) and the rotary moment Tz (maximum with a weight, −50.8 Nmm [±0.8]; minimum without a weight, 18.2 Nmm [±0.9]) significantly in all cases (P < .01). This was found for all materials measured and for both directions of rotation. During rotation with aligners, a simulated occlusal force increases the intrusive force and the rotary moment. The biological adverse side effects of these phenomena remain unclear, especially in patients with periods of bruxism.Abstract
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DOI: 10.2319/030211-151.1
To evaluate cyclic and static shear bond strengths (SSBSs) of metal orthodontic brackets bonded to a porcelain surface using different conditioning protocols. A total of 100 feldspathic porcelain disks were fabricated. The specimens were divided into four equal groups. Porcelain surfaces were conditioned with different protocols. In group 1, hydrofluoric acid and Embrace First-Coat primer were used. In group 2, hydrofluoric acid and silane were utilized. In groups 3 and 4, sandblasting with aluminum oxide powder was done instead of etching. Metal brackets were bonded to the porcelain surfaces using Transbond XT adhesive. SSBS testing was carried out in 10 specimens, while cyclic shear bond strength (CSBS) testing was done in 15 specimens from each group. The data were subjected to analysis of variance, least significant difference post hoc, and Student's t-tests. Embrace First-Coat and silane exhibited a comparable SSBS. The sandblasting process significantly increased SSBS. No significant difference was found in bond SSBS utilizing either hydrofluoric acid and Embrace First-Coat or sandblasting and silane. With regard to CSBS, the use of sandblasting and Embrace First-Coat revealed the highest significant CSBS value, followed by sandblasting and silane. Etching with hydrofluoric acid prior to application of either primer exhibited the least CSBS values; however, no significant difference was found between them. The SSBS was significantly higher than CSBS. Embrace First-Coat could be used successfully as an alternative to silane. Sandblasting provides higher bond strength than did hydrofluoric acid. Cyclic loading significantly decreased bond strength.Abstract
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DOI: 10.2319/011811-34.1
To evaluate the force decay characteristics of nonlatex vs latex interarch elastics within the normal range of salivary pH levels. Two nonlatex groups and one latex quasi-control group were tested. Elastics were stretched to 15 mm and were held for 10 seconds (baseline), 4 hours, 8 hours, and 12 hours in artificial saliva solutions with pH levels of 5.0, 6.0, and 7.5. Force magnitudes were measured at 25 mm of activation. Each specimen was used once. Measurements were assessed using three-way analysis of variance (ANOVA). The three-way interaction between group, pH, and time was not significant (P = .13); the group-by-pH interaction also was not significant (P = .70). However, pH-by-time (P = .0179) and group-by-time (P = .0001) interactions were significant. American Orthodontics nonlatex generated significantly higher loads than Auradonics nonlatex. American Orthodontics nonlatex produced significantly higher forces than American Orthodontics latex at 4, 8, and 12 hours, but not at 10 seconds. American Orthodontics latex was significantly stronger than Auradonics nonlatex at 10 seconds, but not at 4, 8, and 12 hours. No clinically significant correlation between pH and force decay was observed.Abstract
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DOI: 10.2319/010711-8.1
To test the null hypothesis that the form and size of the pharyngeal airways in preadolescents do not differ among various skeletal patterns. Sixty healthy children (mean age, 11.79 ± 1.11 years) were divided into three groups by anteroposterior jaw relationships. Using cone-beam computed tomography, the inclination and the volume of the pharyngeal airway were measured and compared with craniocervical angles and cephalometric variables. Children with Class II malocclusion have a larger angle between the FH plane and midplane of the oropharyngeal airway (ang-OA) compared with children with Class I and III malocclusion (P < .01). Ang-OA was significantly correlated with craniocervical angle (ang-cc) and anteroposterior variables, mainly ANB angle, Pog-N perpendicular (P < .01). Airway volume had a positive correlation with facial depth (P < .01). Children with Class II malocclusion have more backward orientation and smaller volume of the pharyngeal airway than do children with Class I and III malocclusion. Inclination of the oropharyngeal airway might be a key factor in determining the form of the entire pharyngeal airway and is related to head posture.Abstract
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DOI: 10.2319/011011-15.1
To evaluate whether biomarkers of inflammation and periodontal remodeling are differentially expressed in the gingival crevicular fluid (GCF) of patients wearing different types of orthodontic retainers. Thirty-one adult subjects (17 men and 14 women with an age range of 20 to 35 years) were allocated to three different groups. Group 1 consisted of 10 patients wearing fixed retainers, group 2 included 11 patients using lower removable retainers, and group 3 comprised 10 patients without retainers (control). Periodontal health assessment and GCF collection were carried out at two sites per subject: the lingual side of a central lower incisor and the lingual side of a lower second premolar. Aliquots from diluted GCF were screened for the presence of biomarkers using a microarray technique. Group 1 patients exhibited a higher percentage of sites with visible plaque in the incisor region than the other groups (P = .03); no differences were noted in gingival bleeding and probing depths. The median concentrations (pg/mL) of interferon-gamma and interleukin-10 were significantly higher in the premolar sites of patients in group 2 (P = .01 and P = .04, respectively), whereas the concentration of matrix metalloproteinase-9 was significantly higher at the incisors of patients wearing fixed retainers (P = .02). A significant difference between the two sites was seen only in group 2. The presence of different orthodontic retainers may promote specific alterations in the GCF composition. With retention periods potentially becoming longer, this finding may be of clinical significance.Abstract
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DOI: 10.2319/013111-64.1
To explore whether orthodontic residents and orthodontists differ in their attitudes and behavior concerning the treatment of underserved patients and to investigate how background factors such as the providers' gender, ethnicity/race, and age affect these attitudes and behavior. Survey data were collected from 135 residents in US and Canadian graduate orthodontic programs and from 568 active members of the American Association of Orthodontists. Attitudes toward various aspects of treating underserved patients were rated on a five-point scale, with 1 indicating the most negative attitude and 5 indicating the most positive. Orthodontic residents had more positive attitudes about treating poor patients (3.02 vs 1.99; P < .001), pro bono cases (3.87 vs. 3.45; P < .001), and patients with craniofacial anomalies (3.64 vs 3.01; P < .001) or mental retardation (3.13 vs 2.72; P < .001) than orthodontists. However, compared to orthodontists, lower percentages of residents intended to treat pro bono cases (73.5% vs 83%; P = .009) and patients with craniofacial anomalies (63.6% vs 82.9%; P < .001) or mental retardation (55% vs 81.5%; P < .001). The providers' gender did not have an effect on these attitudes and related behavior, while ethnicity/race and age of the providers were relevant. Residents had more positive attitudes concerning the treatment of underserved patients than orthodontists. However, their behavioral intentions did not indicate an increased willingness to provide care for these patients.Abstract
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DOI: 10.2319/022411-134.1
To compare the effectiveness of preoperative administration of ibuprofen and piroxicam on orthodontic pain experienced after separator placement. Ninety patients aged between 13 years 9 months and 18 years 2 months who were to undergo fixed appliance orthodontic treatment were enrolled in this double-blind, parallel-arm, prospective study. Patients were evenly and randomly distributed to any of three experimental groups, as follows: (1) administration of placebo, (2) administration of 400 mg ibuprofen, and (3) administration of 20 mg piroxicam; medications were administered 1 hour before separator placement. The pain perceived was recorded by the patients on a linear and graded Visual Analogue Scale at time intervals of 2 hours; 6 hours; nighttime on the day of appointment; 24 hours after the appointment; and 2 days, 3 days, and 7 days after separator placement during each of the four activities (viz, chewing, biting, fitting front teeth, and fitting back teeth). The results revealed that preoperative administration of 20 mg of piroxicam 1 hour prior to separator placement resulted in a significant decrease in pain levels at 2 hours, 6 hours, nighttime, and 24 hours and on the second and third days after separator placement, compared to patients on a placebo or ibuprofen. Premedication with 20 mg of piroxicam results in significantly decreased pain experienced, compared to premedication with 400 mg of ibuprofen or placebo. Usage of 20 mg of piroxicam 1 hour prior to separator placement is recommended.Abstract
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DOI: 10.2319/030411-159.1
To test the null hypothesis that there is no significant difference in the initial growth pattern among three cleft types before alveolar bone graft (ABG) according to cleft type (unilateral cleft lip and alveolus [UCLA], unilateral cleft lip and palate [UCLP], and cleft palate [CP]). Samples consisted of the UCLA group, the UCLP group, and the CP group. Individuals were treated with the identical surgical technique by the same surgeon and had no history of orthodontic/orthopedic treatment. Lateral cephalograms taken 1 month before ABG were analyzed using 29 variables. One-way analysis of variance (ANOVA) testing and bivariate and logistic regression analyses were performed. An increasing tendency for Class III relationships in the order of UCLA, UCLP, and CP was noted (ANB, AB-to-facial plane angle, AB-to-mandibular plane angle; P < .001, respectively). UCLP and CP groups demonstrated more posterior positioning of the maxilla (SNA, A-to-N-perp; P < .001, respectively) and a hyperdivergent pattern (gonial angle, SN-GoMe angle, FMA; P < .001, respectively) compared with the UCLA group. Because no differences in palatal plane angle and SN-to-occlusal plane angle were noted among the three groups, the hyperdivergent pattern in the UCLP and CP groups might be due to an innate growth pattern and eventual adaptation of the mandible to maxillary growth. UCLP and CP groups showed more Class III relationships (ANB: P < .05, P < .001, respectively) and a more hyperdivergent pattern (FMA: P < .05, P < .01, respectively) than the UCLA group. When the degree of cleft involvement increases from the primary palate to the secondary palate, the predominance of the Class III relationship and the hyperdivergent pattern increases also.Abstract
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Guest Editorial
Academic Opportunities
This listing of academic opportunities is provided as a free service to the profession and the community. Rank: Orthodontic Residency Program Dir. University of Alabama at Birmingham School of Dentistry Dept. of Orthodontics, Birmingham, AL 35294-0007 Contact: Dr. Chung How Kau, (205) 934-1289 FAX: (205) 975-7590 e-mail: ckau@uab.edu Rank: 2 Orthodontic Instructors University of Alabama at Birmingham School of Dentistry Dept. of Orthodontics, Birmingham, AL 35294-0007 Contact: Dr. Chung How Kau, (205) 934-1289 FAX: (205) 975-7590 e-mail: ckau@uab.edu Rank: Graduate Program Director Full-time position Loma Linda University School of Dentistry Program for Advanced Education in OrthodonticsALABAMA
CALIFORNIA
New Publication from The Angle Society
About this monumental sourcebook on the beginnings of modern orthodontics... This is a 4-volume limited-edition hard-cover book set of over 3400 pages. Dr. Angle's correspondence and business accounts from 1899 to 1910, among his most creative years, are included. In addition, all of his patents—45 USA patents and 1 Canadian patent—from 1889 to 1934 (posthumous) are reproduced. These historic materials were preserved by Dr. Anna Hopkins Angle and are now part of the archives of The Angle Society. Typed and handwritten documents have been retyped for legibility and arranged chronologically. The book set is published on a non-profit basis by
Rotational fulcrum and dentoskeletal changes after rapid palatal expansion with tooth-bone-borne (MARPE) and tooth-borne appliances in post-pubertal patients
Luciana Quintanilha Pires Fernandes,
Giselle Naback Lemes Vilani,
Bruno de Paula Machado Pasqua,
Cristiane Barros André, and
Jonas Capelli Jr.
Effects of printing layer thickness and build orientation on the mechanical properties and color stability of 3D-printed clear aligners
Chengzan Wu,
Utkarsh Mangal,
Na Bai,
Hoon Kim,
Geelsu Hwang,
Jung-Yul Cha,
Kee-Joon Lee,
Jae-Sung Kwon, and
Sung-Hwan Choi
Evaluation of treatment outcome assessment using the American Board of Orthodontics Objective Grading System in subjects treated with lower incisor extraction with severe to moderate crowding
Inna Burnett,
Vaibhav Gandhi,
Loiy Alshami,
Jay Patel, and
Janakiraman Nandakumar
Is the Peer Assessment Rating index a valid measure for change in Oral Health-Related Quality of Life following orthodontic treatment? Results of a cohort study
J. Monisha,
Elbe Peter, and
Suja Ani George
Orthodontic forces and moments of three-bracket geometries
Matthew H. Kei,
Paul M. Schneider,
Marie A. Cornelis, and
Paolo M. Cattaneo
eISSN: 1945-7103 | ISSN: 0003-3219
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