Xylitol chewing gum effective at reducing maternal transmission of caries producing bacteria. It has been previously shown that oral Streptococcus mutans contained in the saliva of mothers is readily transmitted to newborn children during infancy. Obviously colonization of these bacteria on primary tooth surfaces could be responsible for causing childhood caries as teeth begin to erupt. It has also been observed that xylitol chewing gum is effective at reducing oral levels of Streptococcus mutans in adults. Could maternal chewing of xylitol gum assist in reducing levels of salivary bacteria in newborn children? That question was
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DOI: 10.2319/052309-292.1
To test the hypothesis that there is no difference in the use of Invisalign® between orthodontists and general practitioners. A questionnaire was mailed to all Invisalign® providers within a 35-mile radius of Stony Brook University. The answers were statistically analyzed. The level of significance was set at P < .05. Orthodontists started more Invisalign® cases (P < .0001). General practitioners started more Invisalign® cases in the last 12 months (P = .0012). For both groups, the percentage of cases started in the last 12 months was inversely related to the number of years certified in Invisalign® (P < .0001). Significant differences in opinion (P < .001) were noted between orthodontists and general practitioners regarding the level of experience necessary to treat a Class I malocclusion with a large diastema, and whether a Class II subdivision case should be treated with Invisalign®. The hypothesis is rejected. The use of Invisalign® by orthodontists and general practitioners was compared, and significant differences were found.Abstract
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DOI: 10.2319/083109-491.1
To determine if measurements obtained from digital models from cone beam computed tomography (CBCT) images were comparable to the traditional method of digital study models by impressions. Digital models of 30 subjects were used. InVivoDental (Anatomage, San Jose, Calif) software was used to analyze CBCT scans taken by a Galileos cone beam scanner (Sirona, Charlotte, NC) with a field of view of 15 × 15 × 15 cm3 and a voxel resolution of 0.125 mm. OrthoCAD (Cadent, Fairview, NJ) software was used to analyze impression scans of patients at different stages of orthodontic treatment. Impressions were taken using alginate and were mailed to OrthoCAD for digital conversion. The scans were then electronically returned in digital format for analysis. The maxillary mean scores for the Little's Index were 9.65 mm for digital models and 8.87 mm for InVivoDental models, respectively. The mandibular mean scores for the Little's Index were 6.41 mm for digital models and 6.27 mm for InVivoDental models, respectively. The mean overjet measurements were 3.32 mm for digital models and 3.52 mm for InVivoDental models, respectively. The overbite measurements were 2.29 mm for digital models and 2.26 mm for InVivoDental models, respectively. The paired t-test showed no statistical significance between the differences in all measurements. CBCT digital models are as accurate as OrthoCAD digital models in making linear measurements for overjet, overbite, and crowding measurementsAbstract
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DOI: 10.2319/062609-358.1
To test the null hypothesis that there is no relationship between infraocclusion and the occurrence of other dental anomalies in subjects selected for clear-cut infraocclusion of one or more deciduous molars. The experimental sample consisted of 99 orthodontic patients (43 from Boston, Mass, United States; 56 from Jerusalem, Israel) with at least one deciduous molar in infraocclusion greater than 1 mm vertical discrepancy, measured from the mesial marginal ridge of the first permanent molar. Panoramic radiographs and dental casts were used to determine the presence of other dental anomalies, including agenesis of permanent teeth, microdontia of maxillary lateral incisors, palatally displaced canines (PDC), and distal angulation of the mandibular second premolars (MnP2-DA). Comparative prevalence reference values were utilized and statistical testing was performed using the chi-square test (P < .05) and odds ratio. The studied dental anomalies showed two to seven times greater prevalence in the infraocclusion samples, compared with reported prevalence in reference samples. In most cases, the infraoccluded deciduous molar exfoliated eventually and the underlying premolar erupted spontaneously. In some severe phenotypes (10%), the infraoccluded deciduous molar was extracted and space was regained to allow uncomplicated eruption of the associated premolar. Statistically significant associations were observed between the presence of infraocclusion and the occurrence of tooth agenesis, microdontia of maxillary lateral incisors, PDC, and MnP2-DA. These associations support a hypothesis favoring shared causal genetic factors. Clinically, infraocclusion may be considered an early marker for the development of later appearing dental anomalies, such as tooth agenesis and PDC.Abstract
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DOI: 10.2319/062509-354.1
To evaluate the success rate of autotransplantation of teeth in consecutive patients and to analyze factors affecting the outcome. The subjects consisted of 215 consecutive patients (101 women and 114 men; aged 9.1–56.4 years, median age 15.2 years [P10 = 11.4, P90 = 19.7]) who had undergone transplantation of a total of 269 teeth, all by the same surgeon. In patients with multiple transplants, only the first transplant was included, to ensure that all transplanted teeth were independent units. The transplants were recorded as unsuccessful if the tooth had been extracted or was surviving but with root resorption or ankylosis. The interval between transplantation and final follow-up was a median 4.8 years (P10 = 2.0, P90 = 5.5) for successful transplants and a median of 2.4 years (P10 = 0.4, P90 = 7.7) for unsuccessful transplants. One-hundred seventy-five (81%) of the transplantations were recorded as successful and 40 (19%) as unsuccessful. Twenty-five teeth had been extracted and 15 had survived but did not fulfill the criteria for success. The success rate of 215 consecutively transplanted teeth was 81%. The highest success rate was for transplantation of premolars to the maxillary incisor region (100%). Complications at surgery such as difficult extraction, deviant root anatomy, or damaged root periodontium affected the outcome. During growth, a successful transplant preserves alveolar bone.Abstract
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DOI: 10.2319/070209-369.1
To determine the histological reaction of the root and bone as a mini-implant approaches the root. Two kinds of mini-implants were inserted into the buccal alveolar bone of 4 beagles (2 males and 2 females). The specimens were classified as the near-root group, the PDL contact group, the root contact group, and the root perforation group. Cementum resorption, dentin resorption, cementum repair, cementum growth, ankylosis, root cracking, and root fracture were assessed as the implant neared the root. The incidence of root resorption increased when the mini-implant was less than 0.6 mm from the root in the near-root group and PDL contact group. Root cracking and root fracture occurred in the root contact group and root perforation group. Bone resorption and ankylosis were observed in some specimens. However, some specimens of the PDL contact group and root contact group had cementum growth or little root resorption despite proximity to the root. In the root perforation group, root resorption and ankylosis occurred on the side opposite the insertion. There is a risk of root contact and severe tissue damage from a thick mini-implant and the drilling procedure, either of which can induce root resorption or ankylosis. Use of smaller mini-implants may reduce root contact and tissue damage. However, the small mini-implant may need enhancement of its stability.Abstract
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DOI: 10.2319/032509-177.1
To describe the ultrastructure of the interface between periodontal tissues and titanium mini-implants in rat mandibles. A titanium mini-implant was placed between the buccal roots of the mandibular first molar of 24 adult rats. After 21, 30, 45, 60, 90, and 120 days of implantation, the mandibular portion was removed and fixed in cacodylate-buffered 2% glutaraldehyde + 2.5% formaldehyde. The material was decalcified and processed for scanning and transmission electron microscopy. Ultrastructural analysis revealed a thin cementum-like layer at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant. The alveolar bone and the periodontal ligament reorganized their constituents around the implant, and a thin cementum-like layer was formed at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant.Abstract
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DOI: 10.2319/072909-427.1
To evaluate the accuracy and precision of cone beam computed tomography (CBCT) with regard to measurements of root length and marginal bone level in vitro and in vivo during the course of orthodontic treatment. Thirteen patients (aged 12–18 years) from an ongoing study and a dry skull were examined with CBCT using multiplanar reformatting for measurements of root length and marginal bone level. For in vivo evaluation of changes in root length, an index according to Malmgren et al was used, along with a modification of this method. The in vitro mean difference between physical and radiographic measurements was 0.05 mm (SD 0.75) for root length and −0.04 mm (SD 0.54) for marginal bone level. In vivo the error was <0.35 mm for root length determinations and <0.40 mm for marginal bone level assessments. Despite changes in tooth positions, the CBCT technique yields a high level of reproducibility, enhancing its usefulness in orthodontic research.Abstract
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DOI: 10.2319/042509-229.1
To test the feasibility of automated lateral cephalometric radiograph (LCR) superimposition using an image fitting algorithm. Using radiopaque markers, we identified seven cephalometric landmarks on three dry skulls, took digital LCRs on each in several rotated positions, and used a custom software program (XRay3D) to automatically superimpose each rotated image on the initial image using an anterior cranial base reference. We measured superimposition error at each landmark and adjusted image brightness levels to simulate potential fitting error due to exposure variation. The greatest mean error for 24 image rotation trials of less than 10° was less than 0.5 mm. Rotations of 10° or more were not reliably superimposed. Errors of 0.2–1.6 mm occurred for ±10% brightness but increased exponentially with further brightness alteration. Automated superimposition of LCRs, using this fitting technique, has great potential when rotation is less than 10° and brightness variation is less than 10%.Abstract
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DOI: 10.2319/061109-330.1
To perform a preliminary study of the short-term effect of fixed, customized lingual orthodontic appliances on periodontal and microbial parameters. The sample comprised 20 subjects (6 males and 14 females) with a mean age of 22.3 years ± 8.6 years. Before (T0) and 4 weeks after placement (T1) of custom-made lingual appliances on the lower teeth only, plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) were measured. A 16S rRNA-based polymerase chain reaction (PCR) method was used to detect Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) in the crevicular fluid. To compare periodontal parameters on bonded lingual (testing) and unbonded palatal (control) and labial (control) sites between T0 and T1, the Wilcoxon test was applied. On the lingual aspects of bonded teeth, a significant increase of BOP (T0: 23.4 ± 22.5%; T1: 46.2 ± 23.5%; P = .001) and PI (T0: 0.3 ± 0.3; T1: 1.0 ± 0.7; P = .001) was observed, but no significant changes for PPD (T0: 2.1 ± 0.4 mm; T1: 2.2 ± 0.3 mm; P = .286) were found. On control sites, no significant changes were recorded for any periodontal parameter. Aa was found in 25% of the patients at baseline (5 subjects) and in 35% of the patients at T1 (2 additional positive subjects), whereas Pg was found in 5% of the cohort at T0 and at T1 (same patient). Even in the short term, insertion of fixed lingual appliances induced a worsening of periodontal parameters restricted to bonded lingual sites.Abstract
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DOI: 10.2319/062709-359.1
To evaluate the treatment effects of twin-block and Mandibular Protraction Appliance-IV (MPA-IV) in the treatment of Class II division 1 malocclusion. Fifty North Indian girls with Class II division 1 malocclusion, in the age range of 9–13 years, were chosen. The subjects were divided among a control group (n = 10), a twin-block group (n = 25), and an MPA group (n = 15). Pre–follow-up and post–follow-up lateral cephalograms of control subjects and pretreatment and posttreatment lateral cephalograms of the treatment subjects were traced manually and subjected to a pitchfork analysis. Neither twin-block nor MPA-IV significantly restricted the forward growth of maxilla. Mandibular growth and improvement in the sagittal skeletal relation were significantly greater in the twin-block subjects. Distal movement of the maxillary dentition and mesial movement of the mandibular dentition were more prominent in the MPA-IV subjects. Molar correction and overjet reductions were significantly greater in the treatment subjects (P < .001). Twin-block and MPA-IV were effective in correcting the molar relationships and reducing the overjet in Class II division 1 malocclusion subjects. However, twin-block contributed more skeletal effects than MPA-IV for the correction of Class II malocclusion.Abstract
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DOI: 10.2319/082409-479.1
To investigate the comparative amount of root shortening between two-step and en masse space closure procedures. Fifty-two patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no dental trauma; no dilacerations of incisor roots, anodontia, or impacted canines; complete root formation at the start of treatment; intact and caries-free incisors; no endodontically treated incisors; Angle Class I or II malocclusion; extraction of four first premolars; and space closure with moderate anchorage. Patients received treatment with either a two-step or an en masse procedure to close the extraction spaces after alignment and leveling with the same preadjusted appliances. Root shortening of the maxillary and mandibular incisors was evaluated on panoramic radiographs, taken before and after space closure, and measured in millimeters. Distortion of measurements caused by panoramic radiographs was corrected by using special metal rods ligated to brackets. Statistical comparisons of root shortening between space closure procedures were investigated with the two-sample t test. No difference was found in the amount of root shortening between space closure procedures. The average root shortening of maxillary central and lateral incisors was 0.43 ± 0.12 mm and 0.58 ± 0.10 mm, respectively, and that of mandibular central and lateral incisors was 0.23 ± 0.07 mm and 0.22 ± 0.06 mm, respectively. No difference should be expected in root resorption between two-step and en masse space closure procedure.Abstract
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DOI: 10.2319/060809-318.1
To compare two clinically applied treatments to stimulate bone healing—low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF)—for their effects on RANKL and OPG expression in osteoblast-like cells in vitro. LIPUS or PEMF was applied to Saos-2 cells for 10 minutes or 3 hours. RANKL and OPG expressions were analyzed at 0, 4, 8, or 12 hours after treatment with real-time PCR. Secreted protein levels in culture supernatant were analyzed at the same posttreatment time points using specific ELISA assays. Neither LIPUS nor PEMF had an effect on RANKL protein expression. OPG protein was significantly increased by LIPUS after 0 and 4 hours (brief short-term effect) and was increased almost 2.5-fold by PEMF after 8 hours. The mRNA levels of OPG and RANKL were hardly affected by LIPUS treatment at any time point. PEMF induced a fivefold increase in RANKL mRNA expression at t = 0. A brief PEMF treatment of 10 minutes resulted in downregulation of RANKL expression after 0 and 4 hours and upregulation at 12 hours. OPG mRNA was downregulated after 8 hours. The effects of LIPUS or PEMF expression on OPG and RANKL are limited. From our experiments, it seems that LIPUS treatment resulted in a quick protein response, while the response of cells to PEMF (3 hours) was delayed. The increase in OPG protein at 8 hours post PEMF treatment is indicative of reduction of osteolysis.Abstract
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DOI: 10.2319/072109-402.1
To test if leptin can be detected in the gingival crevicular fluid (GCF) around moving teeth, and to determine whether any changes occur during orthodontic tooth movement. An upper canine requiring distal movement served as the test tooth; the contralateral canine was used as a control tooth. The control tooth was included in the orthodontic appliance, but was not subjected to the orthodontic force. GCF sampling from the distal sites of the test and control teeth was done at baseline, 1 hour, 24 hours, and 168 hours. Leptin concentrations of the test teeth decreased in a time-dependent manner. When compared with the baseline measurement, the decrease was significant at 168 hours (P < .05). The concentration of leptin in GCF is decreased by orthodontic tooth movement; the results of the present study also suggest that leptin may have been one of the mediators responsible for orthodontic tooth movement.Abstract
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DOI: 10.2319/072909-431.1
To longitudinally investigate the caries risk levels in children undergoing orthodontic treatment with sectional brackets. A total of 42 children scheduled for orthodontic treatment with sectional orthodontic appliances participated in this study. They were divided into two groups based on decayed, missing, and filled permanent and deciduous teeth (DMFT/dmft) scores and counts of mutans streptococci (MS) prior to treatment. One was the low caries risk group (n = 26) and the other was the high caries risk group (n = 16). Paraffin-stimulated whole saliva was collected for examination of salivary flow rate, buffer capacity, and MS and lactobacilli (LB) levels before treatment, 2 and 4 months after appliance placement, and 2, 4, and 8 months after appliance removal. The pretreatment salivary flow rates, buffer capacity, and MS levels remained statistically unchanged during and after active orthodontic treatment in both groups. The levels of LB in the high caries risk group were significantly elevated by appliance placement, but upon appliance removal started to fall significantly and came a little short of the pretreatment levels. In the low caries risk group, the pretreatment levels of LB remained statistically unchanged during and after treatment. There were no significant differences in salivary flow rate or buffer capacity, but there were significant differences in MS and LB scores between the two groups at every measurement time. In children undergoing orthodontic treatment with sectional brackets, LB levels are an important part in making caries risk assessment.Abstract
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DOI: 10.2319/052209-286.1
To test the hypothesis that young people's esthetic perception of dentition midline deviation or the threshold below which they find the deviation “acceptable” depends on the gender and face type of the person with the deviation and the gender of the evaluator. Facial images of six young subjects with three different face types were captured, and their dentition midlines were altered digitally. The images were evaluated by young people with no dental training. Statistical analysis was carried out to determine the threshold for acceptable dentition midline deviation and factors influencing perception. The mean value for the threshold below which a deviation was judged “acceptable” was 2.403 mm (95% confidence interval, 2.315–2.491). The preferences of evaluators did not significantly depend on the direction of the deviation. Both male and female evaluators were significantly less tolerant of deviation in female subjects than in male subjects. However, female evaluators were significantly more tolerant of midline deviations in male subjects than were male evaluators. In addition, the same degree of deviation was most noticeable in male subjects with a tapered face type and least noticeable in female subjects with a square face type. The gender and face type of an individual with dentition midline deviation and the gender of the evaluator do affect young people's esthetic perception of a dentition midline deviation and the threshold below which they find the deviation “acceptable.”Abstract
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DOI: 10.2319/081109-457.1
To investigate the degree of debris, roughness, and friction of stainless steel orthodontic archwires before and after clinical use. For eight individuals, two sets of three brackets (n = 16) each were bonded from the first molar to the first premolar. A passive segment of 0.019- × 0.025-inch stainless steel archwire was inserted into the brackets and tied by elastomeric ligature. Debris level (via scanning electron microscopy), roughness, and frictional force were evaluated as-received and after 8 weeks of intraoral exposure. Mann-Whitney, Wilcoxon signed-rank, and Spearman correlation tests were used for statistical analysis at the .05 level of significance. There were significant increases in the level of debris (P = .0004), roughness of orthodontic wires (P = .002), and friction (P = .0001) after intraoral exposure. Significant positive correlations (P < .05) were observed between these three variables. Stainless steel rectangular wires, when exposed to the intraoral environment for 8 weeks, showed a significant increase in the degree of debris and surface roughness, causing an increase in friction between the wire and bracket during the mechanics of sliding.Abstract
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DOI: 10.2319/060309-315.1
To determine if there is a significant difference in the clinical outcomes of cases treated with 0.018-inch brackets vs 0.022-inch brackets according to the American Board of Orthodontics (ABO) Objective Grading System (OGS). Treatment time and the ABO-OGS standards in alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal relationships, occlusal contacts, interproximal contacts, and root angulations were used to compare clinical outcomes between a series of 828 consecutively completed orthodontic cases (2005–2008) treated in a university graduate orthodontic clinic with 0.018-inch- and 0.022-inch-slot brackets. A two-sample t-test showed a significantly shorter treatment time and lower ABO-OGS score in four categories (alignment/rotations, marginal ridges, overjet, and root angulations), as well as lower total ABO-OGS total score, with the 0.018-inch brackets. The ANCOVA—adjusting for covariants of discrepancy index, age, gender, and treatment time—showed that the 0.018-inch brackets scored significantly lower than the 0.022-inch brackets in both the alignment/rotations category and total ABO-OGS score. There were statistically, but not clinically, significant differences in treatment times and in total ABO-OGS scores in favor of 0.018-inch brackets as compared with the 0.022-inch brackets in a university graduate orthodontic clinic (2005–2008).Abstract
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DOI: 10.2319/070209-370.1
To describe tongue pressure changes before, during, and after crib appliance therapy in mixed dentition open bite cases. A crib appliance was applied to each of the 13 patients in the study group. The control group consisted of six patients. Tongue pressures were measured using a diaphragm-type pressure transducer during rest position and swallowing in changing intervals for 12 months in both groups. Tongue pressures were performed on the upper first molar, upper and lower central incisors, and on the middle spur of the crib appliance. In the study group, the initial resting tongue pressure on the upper molar increased after appliance insertion and was followed by a decreasing trend for 12 months. The resting tongue pressures on the upper and lower incisors remained lower than initial values at the end of 12 months. Swallowing pressures returned to initial values at the end of 12 months, and the changes were insignificant. The resting and swallowing tongue pressures on the middle spur of the crib appliance decreased gradually during the 10 months (P < .05). Pressure changes in the control group were insignificant for all measurements. Open bite values in the study group increased significantly by the end of 12 months. Measurements performed on the crib confirm the tongue adaptation to environmental changes. Resting tongue pressures at the 12th month remained lower than the initial values. These findings indicate adaptive behavior of the tongue to open bite closure and the new position of the incisors.Abstract
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DOI: 10.2319/032309-173.1
To examine changes in gravity fluctuation caused by experimentally altering the area of occlusal contact. Subjects consisted of 15 adult Japanese males with normal stomatognathic function, no missing teeth except for the third molars, and equivalent occlusal contact in the anterior and bilateral posterior regions. Silicon biteplates fabricated for each subject to evaluate gravity fluctuation in relation to changes in occlusal contact area were as follows: RP(−)–OC(+) (entire occlusal surface covered in centric occlusion); RP(+)–OC(+) (entire occlusal surface covered with bite slightly raised); Ant or Pos/RP(+)–OC(+) (anterior or posterior region selectively covered); and RP(+)–OC(−) (only retromolar pads covered, no occlusal coverage). No significant differences in gravity fluctuation were noted between subjects wearing biteplates covering the entire occlusal surface. Subjects wearing biteplates with no occlusal contact showed greater gravity fluctuation than those with occlusal contact. In addition, gravity fluctuation for the Ant/RP(+)–OC(+) group (no occlusal contact in the posterior region) was greater than for RP(+)–OC(+) and Pos/RP(+)–OC(+). However, groups with unilateral occlusal contact in the posterior region exhibited large right and left sway amplitude. These results suggest that occlusal contact, especially posterior occlusal contact, affects gravity fluctuation, and that appropriate occlusion attained by maintaining even occlusal contact in the posterior region is crucial for gravity fluctuation.Abstract
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DOI: 10.2319/042909-235.1
To test the hypothesis that different nickel-titanium (NiTi) archwires may have dissimilar corrosion resistance in a fluoride-containing oral environment. Linear polarization test, a fast electrochemical technique, was used to evaluate the corrosion resistance, in terms of polarization resistance (Rp), of four different commercial NiTi archwires in artificial saliva (pH 6.5) with various NaF concentrations (0%, 0.01%, 0.1%, 0.25%, and 0.5%). Two-way analysis of variance was used to analyze Rp with the factors of archwire manufacturer and NaF concentration. Surface characterizations of archwires were analyzed using scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. Both archwire manufacturer and NaF concentration had a significant influence on Rp of NiTi archwires. Different surface topography was present on the test NiTi archwires that contained the similar surface chemical structure (TiO2 and trace NiO). The surface topography did not correspond to the difference in corrosion resistance of the NiTi archwires. Increasing the NaF concentration in artificial saliva resulted in a decrease in Rp, or corrosion resistance, of all test NiTi archwires. The NiTi archwires severely corroded and showed similar corrosion resistance in 0.5% NaF-containing environment. Different NiTi archwires had dissimilar corrosion resistance in acidic fluoride-containing artificial saliva, which did not correspond to the variation in the surface topography of the archwires. The presence of fluoride in artificial saliva was detrimental to the corrosion resistance of the test NiTi archwires, especially at a 0.5% NaF concentration.Abstract
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DOI: 10.2319/042809-232.1
To investigate whether oral cleansing agents affect the essential work of fracture (EWF) and plastic work of fracture (PWF) for two types of orthodontic thermoplastic retainer materials. Polyethylene-terephthalate-glycol (PETG; Tru-Tain Splint) and polypropylene/ethylene-propylene rubber (PP-EPR) blend (Essix-C+) sheets were compared. For each material, six sets of 25 sheets were thermoformed into double-edge-notched-tension specimens; subsets of five specimens were formed with internotch distances (L) equal to 6, 8, 10, 12, or 14 mm, respectively. Sets were stored (160 hours, 25°C) in air (DRY), distilled water (DW), Original Listerine (LIS), mint Crest ProHealth (CPH), 3% hydrogen peroxide (HP), or Polident solution (POL). Specimens were fractured in tension at 2.54 mm/min. Areas under load-elongation curves were measured to determine total work of fracture (Wf). Linear regressions (Wf vs L [n = 25]) yielded intercepts (EWF) and slopes (PWF). Ninety-five percent confidence intervals were used to evaluate differences in EWF and PWF estimates. PP-EPR blends showed higher EWFs after storage in HP vs storage in DW. PP-EPR blend showed higher EWFs after storage in CPH vs PETG. After HP storage, PP-EPR exhibited lower PWFs than with any other storage conditions. PP-EPR exhibited higher PWFs than PETG after storage in DRY, DW, and LIS. Compared with DW, none of the cleansers decreased the energy to initiate fracture. With one exception, no cleanser decreased the energy to continue plastic fracture extension. In PP-EPR blend, increased resistance to fracture initiation was observed with CPH and HP, yet, surprisingly, HP decreased resistance to plastic fracture growth.Abstract
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DOI: 10.2319/031309-148.1
To determine and compare the longitudinal and transverse roughness parameters of the enamel surface of bovine teeth and evaluate the influence of these parameters on bond strength. Ninety bovine incisors were used. The surface roughness of enamel was measured with a profilometer. For each tooth, five readings were taken in the longitudinal plane and five were taken in the transverse plane of the long axis of the tooth in an area equal to the size of the bracket base. The metal brackets were bonded with Transbond XT, and bond strength was evaluated in a universal test machine. There was a statistical correlation (P < .01) between the longitudinal and transverse roughness measurements. There was no correlation between roughness measurements (longitudinal and transverse) and bond strength (P > .05), nor was there a correlation between total roughness (longitudinal Ra and transverse Ra) and bond strength. The Student's t-test showed that there was a statistically significant difference (P < .05) between longitudinal and transverse roughness. The transverse roughness is greater than the longitudinal roughness, there is a strong correlation between longitudinal and transverse roughness, and there is no correlation between enamel roughness and bond strength.Abstract
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DOI: 10.2319/080809-448.1
To determine the effect of Ankaferd Blood Stopper (ABS) on the shear bond strength (SBS) of orthodontic attachments. The study material consisted of 60 freshly extracted bovine permanent mandibular incisor teeth. All teeth were cleaned and randomly divided into three groups of 20 specimens and etched with 37% phosphoric acid for 15 seconds, washed, and air-dried. Teeth in groups 1 and 2 were contaminated with ABS and blood, respectively. Teeth in group 3 were only air-dried. Roth Generous maxillary central incisor brackets were bonded with Transbond XT to all teeth. SBS was applied using a universal test machine. The one-way analysis of variance (ANOVA) test was used to determine significant differences in SBS between the three groups, and Tukey honestly significant post hoc test was used to compare subgroups. The mean bond strengths and standard deviations of groups 1, 2, and 3 were 9.58 ± 0.95, 4.04 ± 0.69, and 19.56 ± 1.84 MPa, respectively. Specimens contaminated with blood showed a statistically significant lower in vitro SBS than those contaminated with ABS. ABS may be used clinically for obtaining a blood-free tooth surface during application of the brackets on surgically exposed, impacted teeth.Abstract
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Review Article
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DOI: 10.2319/081009-454.1
To evaluate the clinical differences in relation to the use of self-ligating brackets in orthodontics. Electronic databases were searched; no restrictions relating to publication status or language of publication were applied. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) investigating the influence of bracket type on alignment efficiency, subjective pain experience, bond failure rate, arch dimensional changes, rate of orthodontic space closure, periodontal outcomes, and root resorption were selected. Both authors were involved in study selection, validity assessment, and data extraction. Disagreements were resolved by discussion. Six RCTs and 11 CCTs were identified. Meta-analysis of the influence of bracket type on subjective pain experience failed to demonstrate a significant advantage for either type of appliance. Statistical analysis of other outcomes was unfeasible because of inadequate methodological design and heterogenous designs. At this stage there is insufficient high-quality evidence to support the use of self-ligating fixed orthodontic appliances over conventional appliance systems or vice versa.Abstract
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DOI: 10.2319/042009-222.1
The multiple endocrine neoplasia (MEN) syndromes are a relatively uncommon group of genetic disorders characterized by the development of tumors in various endocrine organs. MEN type 2B is of particular interest to the dental profession because of its oral manifestations, which are often some of the earliest clinically detectable signs of the disorder. Early identification of this syndrome is critical because affected patients often develop a characteristic malignancy, medullary carcinoma of the thyroid, at a very early age. We describe a 17-year-old male whose initial diagnosis of MEN-2B was triggered by his orthodontist's request for an oral and maxillofacial pathology consultation to evaluate the patient's oral abnormalities.Abstract
and
DOI: 10.2319/051009-250.1
To describe the location and presence of permanent teeth in nonsyndromic complete bilateral cleft lip and palate patients from the Manitoba Centre for Craniofacial Difference. Records of 1570 patients dating back to 1958 were assessed in this retrospective chart review. Thirty-eight patients met the inclusion criteria, providing 76 cleft site teeth: A tooth on each side of the cleft was considered to have developed from a single lateral incisor tooth bud. The pattern M was assigned when a tooth was found mesial to the cleft, D when distal, MD when mesial and distal and AB if none was found. Pattern M was noted 9.2% of the time; D, 47.4%; MD, 5.3%; and AB, 38.2%. Teeth outside the cleft site: In the maxilla, agenesis occurred in 11.9% of second premolars and 10.5% of central incisors. In the mandible, agenesis occurred in 4.0% of second premolars, 2.6% of lateral incisors, 2.6% of central incisors, and 2.6% of second molars. The lateral incisor was most commonly found distal to the cleft. Agenesis of the lateral incisor and teeth outside the cleft were more common than in noncleft populations.Abstract
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DOI: 10.2319/041209-209.1
The purpose of this report is to describe the dentoalveolar distraction (DAD) technique and to present its effects on the surrounding structures by presenting a Class II case. A 15-year-old skeletal and dental Class II female patient with an overjet of 9 mm was treated by DAD osteogenesis. A custom-made, rigid, tooth-borne intraoral distraction device was used for rapid canine retraction. Osteotomies surrounding the canines were made to achieve rapid movement of the canines within the dentoalveolar segment, in compliance with distraction osteogenesis principles. The amount of canine retraction was 7.5 mm in 12 days at a rate of 0.625 mm per day, with no posterior anchorage loss. The canine teeth showed 1.6 mm extrusion and 11 degrees inclination change (distal tipping) during the same period. Orthodontic treatment continued for 6 months with no clinical and radiographic evidence of complications such as root fracture, root resorption, ankylosis, and soft tissue dehiscence. The DAD technique is an innovative method, because it reduces overall orthodontic treatment time by about 50%, with no unfavorable effects on periodontal tissues and surrounding structures and with no need to use any intraoral or extraoral anchorage appliances.Abstract
Editorial
The ubiquitous orthodontic model has been part of orthodontics as long as we have been looking at orthodontic questions. Still we have no evidence based way of rating a model. Standard practice is to hold up or mount a set of models for visual inspection and offer an opinion presumably based on our individual concept of what constitutes ideal or perfection. We are biased by Angle's “old glory” concept, but we are aware of individual variation. What is missing is an agreed upon gold standard individualized for this patient. Everyone knows of tooth size issues, problems that arise with upper
Lip incompetence resolved by active vertical control in nonsurgical treatment of a protrusion case with vertical maxillary excess
Johnny JL Liaw,
Jae Hyun Park,
Fang Fang Tsai,
Betty MY Tsai, and
Wendy WT Liao
Changes in glenoid fossa of adult female patients with Class II division 1 malocclusion during premolar extraction treatment and mini-implant anchorage: a cone-beam computed tomography study
Xiao-Chuan Fan,
Lin-Sha Ma,
Marco Aoqi Rausch,
Li Chen,
Qing Zhang,
Diwakar Singh,
Xiaohui Rausch-Fan, and
Xiao-Feng Huang
Differences in the cooperation of teenagers for orthodontic treatment: Z Generation versus Y Generation
Nitsan Miron,
Nir Shpack,
Michael V. Joachim, and
Amir Laviv
Miniscrew-assisted slow palatal expansion with bone borne expander in adult patients: a case control study on consecutively treated patients
Niki Arveda,
Marco Migliorati,
Anna De Mari,
Filippo Forin Valvecchi,
Irene Schiavetti,
Fabio Annarumma,
Giovanni Battista, and
Hussein Aghazada
Influence of personalized replacement protocol and low-level laser therapy combined with vibration on tooth movement rate and tooth movement accuracy in clear aligner treatment: a randomized clinical trial
Zeyao Miao,
Liling Ren,
Haijuan Zhang,
Chengdong Zheng,
Yuxuan Yang,
Jinyuan Zhu,
Yandong Han, and
Shuang Wang
eISSN: 1945-7103 | ISSN: 0003-3219
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