Evaluation of enamel demineralization in adolescents after rapid maxillary expansion using the quantitative light-induced fluorescence method: A single-center, randomized controlled clinical trial.

INTRODUCTION: The aim of this 2-arm parallel trial was to evaluate enamel demineralization after rapid maxillary expansion (RME) compared with an untreated control group using quantitative light-induced fluorescence. METHODS: Thirty-six patients who needed RME as part of their orthodontic treatment were separated randomly into either the control group or the intervention group (RME). Eligibility criteria included crossbite, no previous orthodontic treatment, no systemic disease, and all permanent teeth erupted except second and third molars. The main outcome was quantitative evaluation of demineralization, and assessment of the vulnerability of each tooth to demineralization was the secondary outcome. Randomization was made at the start of the study with preprepared random number tables. Blinding was applicable for outcome assessment only. Patients in the RME group underwent expansion with a bonded acrylic expander; patients in the control group were untreated. Records were taken using quantitative light-induced fluorescence Digital Biluminator (Inspektor Research Systems, Amsterdam, The Netherlands) in pretreatment and posttreatment observation phases. The presence and extent of lesions on the buccal surfaces of all teeth, except the second and third molars, were assessed. The fluorescence loss, lesion area, and percentage of fluorescence loss were determined using the system's software. The numbers of teeth with more than a 5% change in fluorescence loss, were calculated. Data were analyzed with Wilcoxon signed rank, Mann-Whitney U, multivariate analysis of variance, and chi-square tests (P <0.05). Risk and odds ratios were calculated. RESULTS: A total of 36 patients were randomized to either the RME or the control group in a 1:1 ratio. This study was completed with 18 patients in the RME group (8 girls, 10 boys; mean age, 14.2 ± 1.0 years) and 18 patients in the control group (10 girls, 8 boys; mean age: 14.1 ± 0.8 years). All patients completed the study, and none were lost to follow-up. The area of demineralization decreased in the RME group (-17.50 mm2), which was a significantly greater decrease than in the control group (0.00) (effect size, -2.63; mean difference, -87.94; 95% confidence interval, -223.75-47.86; P = 0.008). No statistically significant difference was found for fluorescence loss. The numbers of teeth with demineralization and remineralization were higher in the treatment group. According to the risk ratio, the difference between groups regarding demineralization was not significant. No harm was found except gingivitis associated with the bonded appliance. CONCLUSIONS: RME therapy using a bonded expander does not increase enamel demineralization. REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement.

Facial soft-tissue changes after rapid maxillary expansion analyzed with 3-dimensional stereophotogrammetry: A randomized, controlled clinical trial.

OBJECTIVE: To evaluate three-dimensional (3-D) soft tissue facial changes following rapid maxillary expansion (RME) and to compare these changes with an untreated control group. MATERIALS AND METHODS: Patients who need RME as a part of their orthodontic treatment were randomly divided into two groups of 17 patients each. Eligibility criteria included having maxillary transverse deficiency with crossbite, and to be in the normal range according to body mass index. In the first group (mean age  =  13.4 ± 1.2 years), expansion was performed. The second group received no treatment initially and served as untreated control (mean age  =  12.8 ± 1.3 years). Skeletal and soft tissue changes were evaluated using posteroanterior cephalograms and 3-D facial images. The primary outcome of this study was to assess the soft tissue changes. The secondary outcomes were evaluation hard tissue and soft tissue relations. Randomization was done with preprepared random number tables. Blinding was applicable for outcome assessment only. MANOVA, t-test, and correlation analyses were used (P  =  .05). RESULTS: In both groups, there was a general trend of increase for the transverse skeletal measurements, but these increases were more limited in the control group. Alar base width was greater in the treatment group (P  =  .002). Pogonion soft tissue point (P  =  .022) was located more posteriorly in the expansion group compared with the control group. CONCLUSIONS: Soft tissue changes between groups were similar, except for the alar base, which became wider in the treatment group. Weak correlations were found between the skeletal and soft tissue changes.

Light emitting diode mediated photobiomodulation therapy improves orthodontic tooth movement and miniscrew stability: A randomized controlled clinical trial.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the effects of light-emitting diode-mediated-photobiomodulation therapy (LPT) on the stability of miniscrews, rate of orthodontic tooth movement, and interleukin-1ß levels in gingival and peri-implant crevicular fluid. MATERIALS AND METHODS: This study was a double blind, randomized placebo/control matched pairs clinical trial to test the efficacy of LPT. This split-mouth design study consisted of 20 patients (13 girls, 7 boys). The eligibility criteria included patients who had extraction of maxillary first premolars. Mini-screws were placed between maxillary first molars and second premolars on both sides as anchorage units. LPT was applied with an energy density of 20 mW/cm2 over a period of 21 successive days (20 minutes per day) over the movement of canine teeth on the test side and using a pseudo application on the placebo side. The main outcome of this study was to assess effect of LPT on the rate of orthodontic tooth movement. The secondary outcomes were measuring stability of miniscrews and interleukin-1ß levels in gingival and peri-implant crevicular fluid after LPT. Randomization was accomplished with random LPT application side selection by coin toss. Measurements were made by blinding clinicians. Blinding of the patients was achieved using the same LPT device on both sides but irradiating only one side. For statistical comparison, paired samples t-test and one-way analysis of variance (ANOVA) were used at P < 0.05 level. RESULTS: Miniscrew stability was similar between control and LPT groups at baseline (T0) and the 1st month (T1). However, miniscrew stability was significantly increased in the LPT group in 2nd (T2) and 3rd (T3) months. Comparison of tooth movement during three different time intervals (T1-T0, T2-T1, and T3-T2) revealed that statistically significantly increased in every time intervals after LPT. No statistically significant change was detected in the IL-1ß levels between groups. CONCLUSION: LPT had the potential of accelerating orthodontic tooth movement and had a positive effect on miniscrew stability. Lasers Surg. Med. 48:936-943, 2016. © 2016 Wiley Periodicals, Inc.

Different pulse modes of Er:YAG laser irradiation: effects on bond strength achieved with self-etching primers.

OBJECTIVE: The aim of this study was to compare the effects of different pulse modes of Er:YAG laser on shear bond strength (SBS) of orthodontic brackets bonded with self-etching primers (SEP) and phosphoric acid etching. MATERIALS AND METHODS: A total of 120 human mandibular third molars were randomly assigned to 3 groups of 40 specimens depending on the bonding procedure to be used. The groups were divided into two subgroups according to the pulse mode of the erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation as medium-short pulse (MSP) mode and quantum-square pulse (QSP) mode at 120 mJ, 10 Hz, 1.2 W. In each subgroup, the mesio- or distobuccal tooth surfaces were randomly assigned as experimental or control sides. After surface preparation with different modes of Er:YAG laser on experimental side, whole buccal tooth surfaces were treated with phosphoric acid etching or two different SEPs. Then metallic brackets were bonded with Transbond XT (3 M Unitek, Monrovia, CA, USA) or Kurasper F (Kuraray, Okayama, Japan). SBS values and the amount of adhesive remaining on the tooth after debonding were assessed. One-way analysis of variance (ANOVA) was used to evaluate the changes in mean SBS between groups resulting from laser etching, followed by post hoc test of Tukey. RESULTS: There were statistically significant differences between the experimental and control sides of all groups (p < 0.05). CONCLUSION: Laser etching with QSP and MSP modes increases the SBS of metallic brackets and Er:YAG laser irradiation with QSP mode increases the SBS of SEPs.

Outcomes of different Class II treatments : Comparisons using the American Board of Orthodontics Model Grading System.

OBJECTIVE: The aim of this study was to evaluate the clinical outcomes of three different Class II treatment modalities followed by fixed orthodontic therapy, using the American Board of Orthodontics Model Grading System (ABO-MGS). MATERIALS AND METHODS: As a retrospective study, files of patients treated at postgraduate orthodontic  clinics in different cities in Turkey was randomly selected. From 1684 posttreatment records, 669 patients were divided into three groups: 269 patients treated with extraction of two upper premolars, 198 patients treated with cervical headgear, and 202 patients treated with functional appliances. All the cases were evaluated by one researcher using ABO-MGS. The χ (2), Z test, and multivariate analysis of variance were used for statistical evaluation (p < 0.05). RESULTS: No significant differences were found among the groups in buccolingual inclination, overjet, occlusal relationship, and root angulation. However, there were significant differences in alignment, marginal ridge height, occlusal contact, interproximal contact measurements, and overall MGS average scores. The mean treatment time between the extraction and functional appliance groups was significantly different (p = 0.017). CONCLUSION: According to total ABO-MGS scores, headgear treatment had better results than functional appliances. The headgear group had better tooth alignment than the extraction group. Headgear treatment resulted in better occlusal contacts than the functional appliances and had lower average scores for interproximal contact measurements. Functional appliances had the worst average scores for marginal ridge height. Finally, the functional appliance group had the longest treatment times.

Reproducibility and reliability of three-dimensional soft tissue landmark identification using three-dimensional stereophotogrammetry.

OBJECTIVE: To evaluate the intraexaminer repeatability and interexaminer reproducibility of soft tissue landmarks on three-dimensional (3-D) stereophogrammetric images. MATERIALS AND METHODS: Thirty-four stereophotogrammetric images were taken and 19 soft tissue points were identified. The images were obtained using the 3-DMD Face (3-DMD TM Ltd, Atlanta, Ga) system. Two examiners marked 34 images manually with a mouse-driven cursor 4 weeks apart. Intraexaminer marking differences were calculated and classified as <0.5 mm, 0.5-1 mm, and >1 mm. Intraclass correlation coefficients were calculated for intraexaminer reliability. A paired-samples t-test was used to evaluate the difference between the examiners. Interexaminer reproducibility was evaluated by kappa analysis. Statistical significance was set at P < .05. RESULTS: Only one landmark (labiale superior) had an intraexaminer marking difference less than 0.5 mm. Existing landmarks had an intraexaminer difference less than 1 mm, but higher than 0.5 mm. The intraclass correlation coefficients (ICCs) indicated good intraexaminer repeatability for both observers. The ICC range for examiners 1 and 2 was 0.986-1.000 and 0.990-1.000, respectively. Kappa scores showed good interexaminer agreement, especially on the z-axis. CONCLUSIONS: Except labiale superior, the soft tissue landmarks used in this study were shown to have moderate reproducibility, but the difference between the landmarks was less than 1 mm, and they had clinically acceptable reproducibility.

Natural head position and lower incisor irregularity: Is there a relationship?

OBJECTIVE: The aim of this study was to assess the relationship between dynamic measurements of natural head position (NHP) and lower incisor irregularity to identify potential gender differences. MATERIALS AND METHODS: A total of 103 plaster models and dynamic NHP measurements were taken from 51 male (mean age: 14.20 ± 2.51 years) and 52 female (mean age: 15.02 ± 2.67 years) subjects. The dynamic NHP data were gathered by using an inclinometer device and a portable data logger. Lower incisor irregularity was measured with Little's irregularity index. The Mann-Whitney U and Kruskal-Wallis rank tests were used at a significance level of p < 0.05. To evaluate the correlation between NHP and lower incisor irregularity, Spearman correlation coefficients (r) were calculated. RESULTS: There were significant gender differences in the sagittal measurements of NHP (p = 0.031) and incisor irregularity (p = 0.023). A Kruskal-Wallis test revealed no significant difference in NHP measurements between subjects presenting different levels of irregularity. Females displayed no significant correlation between incisor irregularity and any NHP measurement. However, in the males high correlation coefficients between incisor irregularity and sagittal NHP measurements (r = 0.369; p = 0.008) were noted. CONCLUSION: Significant correlations between lower incisor irregularity and sagittal NHP measurements in males were observed. Females had a more forwardly inclined NHP than males. Moreover, male subjects displayed greater incisor irregularity than female subjects.

Effects of different pre-treatment methods on the shear bond strength of orthodontic brackets to demineralized enamel.

OBJECTIVE: To compare the effects of different treatment methods used for the enamel damage, on the shear bond strength (SBS) and fracture mode of orthodontic brackets. MATERIALS AND METHODS: Freshly-extracted 140 premolars were randomly allocated to seven groups: Group I was considered as the control of other groups. The remaining groups were exposed to demineralization. In group II, brackets were directly bonded to the demineralized enamel surface. CPP-ACP paste (GC Tooth Mousse), fluoride varnish (Bifluorid 12), microabrasion with a mixture prepared with 18% hydrochloric acid and fine pumice powder, microabrasion with an agent (Opalustre) and resin infiltrant (Icon®) were applied in Groups III, IV, V, VI and VII, respectively. The specimens were tested for SBS and bond failures were scored according to the Adhesive Remnant Index (ARI). Analysis of variance and Tukey tests were used to compare the SBS of the groups. ARI scores were compared with G-test. The statistical significance was set at p < 0.05 level. RESULTS: Statistically significant differences were found among seven groups (F = 191.697; p < 0.001). The SBSs of groups I (mean = 18.8 ± 2.0 MPa) and VII (mean = 19.1 ± 1.4 MPa) were significantly higher than the other groups. No statistically significant difference was found between groups IV (mean = 11.5 ± 1.2 MPa) and V (mean = 12.6 ± 1.5 MPa). The differences in ARI scores of the groups were statistically significant (p < 0.01). CONCLUSIONS: All demineralization treatment methods improve bonding to demineralized enamel. Resin infiltrant application after demineralization showed similar bond strength values as intact enamel.

Effects of different orthodontic primers on enamel demineralization around orthodontic brackets.

AIM: The purpose of this work is to evaluate the effectiveness of one self-etching and two filled orthodontic primers on enamel demineralization around orthodontic brackets. METHODS: Brackets were bonded to 84 bovine teeth and the vestibular enamel surfaces covered with acid-resistant nail varnish exposing 1 mm of space on each side of the bracket base. The teeth were allocated to four groups, using either Transbond XT conventional primer on etched enamel (group 1), Transbond Plus Self-Etching Primer on untreated enamel (group 2), Pro Seal filled resin primer on etched enamel (group 3), or Opal Seal filled resin primer on etched enamel (group 4). Each tooth was subjected to 15,000 strokes of brushing followed by exposure to an acid challenge. Calcium-ion release from each sample was calculated using atomic absorption spectrophotometry. Data were analyzed using one-way ANOVA and a post hoc Tukey test. Differences were considered statistically significant at p ≤ 0.05. RESULTS: Statistically significant differences were observed between the four groups (p < 0.001). No significant difference was found between the controls (group 1) and the Opal Seal group. Higher calcium release was observed in the Pro Seal group and the self-etching primer group compared to the controls. The highest calcium release was recorded in the self-etching primer group. CONCLUSION: Filled sealants may not have a protective effect against enamel demineralization. Transbond Plus Self-Etching Primer should be used cautiously, considering the risk of demineralization involved in its application.

Curve of Spee and its relationship to vertical eruption of teeth among different malocclusion groups.

INTRODUCTION: Our objectives were to assess the depth of the curve of Spee (COS) in different malocclusion groups, to relate this to the eruption of anterior or posterior teeth quantitatively, and to determine whether the depth of the COS is affected by the vertical eruption of anterior or posterior teeth. METHODS: Two hundred conventional lateral cephalograms and 3-dimensional models of untreated patients (70 boys, mean age: 16.4 ± 1.4 years; 130 young women, mean age: 18.1 ± 1.8 years) were included and assigned to 4 malocclusion groups as Class I, Class II Division 1, Class II Division 2, and Class III. The depth of the COS, overjet, and overbite were measured on 3-dimensional models. The perpendicular distance between the incisal tip of the mandibular central incisor (L1-MP), the deepest point of the COS (S-MP), and the distobuccal cusp tip of the mandibular second molar (L7-MP) to the mandibular plane were calculated and proportioned with each other. The Pearson correlation coefficient was calculated, and multiple linear regression analysis was carried out. Also, multivariate analysis of variance was performed at the P <0.05 level. RESULTS: The mesiobuccal cusp of the first molar was the deepest part of the COS in all groups, with a maximum depth of 2.44 ± 0.73 mm in the Class II Division 1 subjects and a minimum depth of 1.76 ± 0.94 in the Class III subjects. The depth of the COS changed as follows: Class II Division 1 > Class II Division 2 > Class I > Class III malocclusion groups. Statistically significant positive correlations were found between the depth of the COS and L1-MP/S-MP (r = 0.541) and L7-MP/S-MP (r = 0.269) in the Class I and Class III subjects, and between the depth of the COS and overjet (r = 0.483) and L7-MP/S-MP (r = 0.289) in the Class II Division 1 subjects. All variables except overjet had positive correlations with the depth of the COS in Class II Division 2 subjects. The multivariate analysis of variance showed statistically significant differences in overjet, overbite, L1-MP/S-MP, L7-MP/S-MP, and the depth of the COS (P <0.001) among the groups. CONCLUSIONS: Although the overjet differed, vertical eruption of the anterior teeth did not differ among the different malocclusion groups and had a significant contribution to the depth of the COS in subjects with Class I and Class III malocclusions.

Bone marrow mesenchymal stem cells enhance bone formation in orthodontically expanded maxillae in rats.

OBJECTIVE: To transplant bone marrow-derived mesenchymal stem cells (MSCs) into the interpremaxillary suture after rapid maxillary expansion with the aim of increasing new bone formation in the suture. MATERIALS AND METHODS: Nineteen male Wistar rats were divided into two groups (control, n  =  9; experimental, n  =  10). Both groups were subjected to expansion for 5 days, and 50 cN of force was applied to the maxillary incisors with a helical spring. Pkh67(+) (green fluorescent dye)-labeled MSCs were applied to the interpremaxillary suture after force application into the interpremaxillary suture of rats. Bone formation in the sutural area was histomorphometrically evaluated, including the amount of new bone formation (µm(2)), number of osteoblasts, number of osteoclasts, and number of vessels. Mann-Whitney U-test was used for statistical evaluation at the P < .05 level. RESULTS: After 10 days of retention, Pkh67(+) can be detected in suture mostly in the injection site under fluorescence microscope. Histomorphometric analysis revealed that a single local injection of MSCs into the midpalatal suture increased the new bone formation in the suture by increasing the number of osteoblasts and new vessel formation, compared with controls injected with phosphate-buffered saline. CONCLUSIONS: This preclinical study might provide foundations for the underlying potential clinical use of MSCs after maxillary expansion. Given the fact that MSCs are currently in use in clinical trials, this approach might be a feasible treatment strategy to accelerate new bone tissue formation in midpalatal suture and to shorten the treatment period for patients undergoing maxillary expansion reinforcement.

Development of the curve of Spee in Class II subdivision malocclusion: a longitudinal study.

OBJECTIVE: To compare the depth of curve of Spee (COS) in Class I and II sides of Class II subdivision malocclusion longitudinally and to describe the changes in the COS in relation to dental arch over time. MATERIALS AND METHOD: The study group comprised 17 subjects exhibiting Class II subdivision malocclusion. The depth of COS, intermolar width, distances from mesial anatomic contact points of the first permanent molars to the contact point of the central incisors in Class I and II sides and arch length in mandible were analysed on digital models in three different time points based on cervical vertebral maturation (T1; mean age: 12.4 years, T2; mean age: 15.1 years, and T3: mean age: 19.1 years). Pearson's correlation coefficients were calculated and linear multiple regression analysis with enter method was carried out. RESULTS: No significant differences were found in the depth of COS between Class I and II sides in all time periods. The mesiobuccal cusp of the first molar was the deepest part of COS in both sides and in all time periods, with a maximum depth of 2.37±0.83mm in T1 and a minimum depth of 1.91±0.66mm in T3. Between baseline and final follow-up; the depth of COS, ach length, and distance in Class I side decreased significantly. Arch length had a significant correlation with the depth of COS (r = 0.471) in T3. CONCLUSIONS: As the depth of COS did not differ between either the Class II or I sides, the same mechanics can be used to level the COS in either sides of the mandibular arch.

Effect of LED-mediated-photobiomodulation therapy on orthodontic tooth movement and root resorption in rats.

The aim of this experimental study was to evaluate the effects of light-emitting diode-mediated-photobiomodulation therapy (LPT), on the rate of orthodontic tooth movement (TM) and orthodontically induced root resorption, in rats. Twenty male 12-week-old Wistar rats were separated into two groups (control and LPT) and 50 cN of force was applied between maxillary left molar and incisor with a coil spring. In the treatment group, LPT was applied with an energy density of 20 mW/cm(2) over a period of 10 consecutive days directly over the movement of the first molar teeth area. The distance between the teeth was measured with a digital caliper on days 0 (T0), 10 (T1), and 21 (T2) on dental cast models. The surface area of root resorption lacunae was measured histomorphometrically using digital photomicrographs. Mann-Whitney U and Wilcoxon tests were used for statistical evaluation at p < 0.05 level. TM during two different time intervals (T1-T0 and T2-T1) were compared for both groups and a statistically significant difference was found in the LPT group (p = 0.016). The TM amount at the first time period (1.31 ± 0.36 mm) was significantly higher than the second time period (0.24 ± 0.23 mm) in the LPT group. Statistical analysis showed significant differences between two groups after treatment/observation period (p = 0.017). The magnitude of movement in the treatment group was higher (1.55 ± 0.33 mm) compared to the control group (1.06 ± 0.35 mm). Histomorphometric analysis of root resorption, expressed as a percentage, showed that the average relative root resorption affecting the maxillary molars on the TM side was 0.098 ± 0.066 in the LPT group and 0.494 ± 0.224 in the control group. Statistically significant inhibition of root resorption with LPT was determined (p < 0.001) on the TM side. The LPT method has the potential of accelerating orthodontic tooth movement and inhibitory effects on orthodontically induced resorptive activity.

Buccal cortical bone thickness at miniscrew placement sites in patients with different vertical skeletal patterns.

OBJECTIVE: Cortical bone thickness plays an important role in the primary stability of miniscrews. The purpose of this study was to evaluate the buccal cortical bone thickness in adolescent subjects with different vertical skeletal patterns using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: We examined the CBCT images of 75 patients (30 males, 45 females; mean age 16.5 years; range 15.3-17.7 years) in the present study. High-, average- and low-angle subgroups were generated according to SN-GoMe angle. On volumetric images, we measured the buccal cortical bone thickness from canine to the second molar teeth at heights of 5, 7 and 9 mm from cemento-enamel junction (CEJ). For statistical evaluation, the Wilcoxon signed rank, Kruskal-Wallis and Tukey HSD tests were applied at the p < 0.05 level. RESULTS: Buccal cortical bone was thickest in the low-angle group. We observed statistically significant differences in the maxilla between the high- and low-angle groups at all levels. In the mandible, we noted statistically significant differences between high-angle and low-angle groups in the canine-first premolar regions at heights of 5 and 7 mm, and in the second premolar-first molar region at 7 mm height from CEJ. Significant differences were also present between the first and second premolars at heights of 7 and 9 mm. Average cortical bone thickness ranged from 1.10-1.37 mm in the maxilla and 1.20-3.28 mm in the mandible for all groups. CONCLUSION: Buccal cortical bone thickness in adolescents varied in different vertical skeletal patterns and was greater in the mandible than in the maxilla, with the distance increasing from the CEJ to the apex. As the buccal cortical bone is thinner in high-angle patients, patient-specific measures should be taken when performing miniscrew treatment.

Longitudinal evaluation of dental arch asymmetry in Class II subdivision malocclusion with 3-dimensional digital models.

INTRODUCTION: Class II subdivision malocclusions with their asymmetric occlusal relationships often pose treatment difficulties. The aim of this study was to evaluate the longitudinal changes of dental arch asymmetry in untreated subjects with Class II subdivision malocclusion. METHODS: From 706 files from the University of Michigan Growth Study, longitudinal records of 17 untreated subjects with Class II subdivision malocclusion were included this study. Dental arch changes at 3 consecutive longitudinal intervals, defined by the cervical vertebral maturation method, were analyzed on digital dental models. The average ages of the subjects were 12.4, 15.1, and 19.1 years at the 3 time periods, respectively. Maxillary and mandibular reference lines were constructed and used for the intra-arch asymmetry measurements. The Friedman test and analysis of variance with repeated measures were used to determine dental arch asymmetries at the P <0.05 level. RESULTS: All subjects were found to have a type 1 Class II subdivision malocclusion characterized by distal positioning of the mandibular first molar on the Class II side. No statistically significant intra-arch asymmetry changes were found for the maxillary and mandibular dental arches in any time period. Between the baseline and the final follow-up, the data indicated decreases in maxillary and mandibular intercanine arch widths and arch lengths symmetrically. CONCLUSIONS: The results of this study indicate that the dental arch asymmetry in patients with Class II subdivision malocclusions did not improve or worsen with growth.

Comparison of orthodontic treatment outcomes in nonextraction, 2 maxillary premolar extraction, and 4 premolar extraction protocols with the American Board of Orthodontics objective grading system.

INTRODUCTION: The aim of this study was to compare the orthodontic clinical outcomes of 2 maxillary premolar extraction, 4 premolar extraction, and nonextraction treatment protocols. METHODS: The sample for this retrospective study was selected randomly from the archives of postgraduate orthodontic clinics in various cities in Turkey. Posttreatment records including dental casts and panoramic radiographs of 1098 patients were divided into 3 groups: group 1 comprised 269 patients treated with 2 maxillary first premolar extraction, group 2 comprised 267 patients treated with 4 premolar extraction, and group 3 comprised 562 patients treated with a nonextraction protocol. Only 1 researcher evaluated all subjects using the American Board of Orthodontics objective grading system. RESULTS: There were no statistically significant differences among the 2 maxillary premolar extraction, 4 premolar extraction, and nonextraction treatment groups for alignment, marginal ridge height, buccolingual inclination, overjet, and interproximal contact measurements. Statistically significant differences were found in occlusal contacts, occlusal relationships, and root angulation measurements between the 4 premolar extraction and the nonextraction groups. CONCLUSIONS: The nonextraction patients had more teeth in occlusion than did the 4 premolar extraction patients. The nonextraction patients finished with more satisfactory sagittal dental relationships. The 4 premolar extraction group had the least satisfactory sagittal dental relationships. The nonextraction patients finished with better root angulations.

Relationship between pretreatment case complexity and orthodontic clinical outcomes determined by the American Board of Orthodontics criteria.

OBJECTIVE: To evaluate the relationship between pretreatment case complexity and orthodontic treatment outcomes. MATERIALS AND METHODS: The total sample contained 1693 cases (853 females and 840 males, mean age  =  16.3 years) from the archives of postgraduate orthodontic clinics. The complexity of each case was evaluated using the American Board of Orthodontics (ABO) Discrepancy Index (DI), and orthodontic clinical outcomes were evaluated using the ABO Objective Grading System (OGS). Only one investigator evaluated all cases. Multivariate analysis of variance, correlation analysis, and multiple variable regression analysis were used for statistical evaluation (P < .05 as significant). RESULTS: The mean total DI score was 16.2, and the mean total OGS score was 18. No significant correlation was found between the total DI and the total OGS scores. However, pretreatment overbite, lateral open bite, crowding, buccal posterior crossbite, and other components affected the total OGS score significantly. The highest percentage of passing OGS values was found for cases of medium-level complexity. CONCLUSION: This retrospective study of university clinical records showed that the posttreatment clinical outcomes were significantly affected from pretreatment case complexity. Posttreatment alignment was affected significantly from pretreatment buccal posterior crossbite and cephalometric values. Similarly, posttreatment buccolingual inclination was affected from pretreatment anterior open bite, occlusion, and other factors. Occlusal contacts were affected significantly from pretreatment lingual posterior crossbite and other factors. In addition, we determined that posttreatment root angulations were affected significantly from pretreatment crowding values.

Dentoskeletal effects of Twin Block and Herbst appliances in patients with Class II division 1 mandibular retrognathy.

OBJECTIVE: The aim of this study is to evaluate dentoskeletal effects of Herbst and Twin Block (TB) appliance therapies in Skeletal Class II malocclusion. SUBJECTS AND METHODS: Herbst group consisted of 11 girls and 9 boys (mean age = 12.74 ± 1.43 years), TB group comprised of 10 girls and 10 boys (mean age = 13.0 ± 1.32 years), and control group included 9 girls and 11 boys (mean age = 12.17 ± 1.47 years). Mean treatment/observation times were 15.81 ± 5.96 months for Herbst, 16.20 ± 7.54 months for TB, and 15.58 ± 3.13 months for control group. Pre-treatment (T0) and post-treatment (T1) lateral cephalograms were traced using a modified Pancherz's cephalometric analysis. Inter-group differences were evaluated with one-way analysis of variance, and intra-group differences were assessed with paired samples t-test at the P < 0.05 level. RESULTS: In control group, all sagittal and vertical skeletal measurements increased as a result of continuing growth. However, skeletal discrepancy and overjet remained unchanged. After functional appliance therapy, greater increases were recorded in TB group for all mandibular skeletal measurements compared with those in control group. Upper dental arch distalization and lower incisor protrusion were significant in Herbst group, compared with control. All face height measurements increased after functional appliance therapy. IMPLICATIONS AND CONCLUSIONS: In TB group, the treatment effects were mainly due to mandibular skeletal changes. Both skeletal and dental changes contribute to Class II correction with Herbst appliance therapy. Herbst appliance may be especially useful in Skeletal Class II patients with maxillary dentoalveolar protrusion and mandibular dentoalveolar retrusion, whereas TB appliance may be preferred for skeletal mandibular retrognathy patients.

OPG and RANKL levels around miniscrew implants during orthodontic tooth movement.

INTRODUCTION: The aim of this study was to determine the peri-miniscrew implant crevicular fluid receptor activator of nuclear factor-кB ligand (RANKL) and osteoprotegerin (OPG) levels around loaded and unloaded miniscrew implants at different time intervals. METHODS: Twenty loaded and 16 unloaded miniscrew implants were included in this study. All miniscrew implants were placed bilaterally between the maxillary second premolars and first molars as anchorage units for canine distalization. Peri-miniscrew implant crevicular fluid was taken from the mesiobuccal aspects of the loaded and unloaded miniscrew implants before loading; at 24, 48, and 168 hours; and on day 30 after force application. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the peri-miniscrew implant crevicular fluid samples. Wilcoxon, Mann-Whitney U, and Spearman correlation tests were used for statistical evaluations at the P <0.05 level. RESULTS: Although the total amount of OPG was not different between the groups, the total amount of RANKL was significantly elevated in the loaded miniscrew implant group (P <0.05) at all time periods. Peri-miniscrew implant crevicular fluid volume was the highest at 48 hours in the loaded group. Also, the OPG/RANKL ratio in the peri-miniscrew implant crevicular fluid was significantly decreased in the loaded miniscrew implant group. CONCLUSIONS: The OPG and RANKL levels vary around loaded and unloaded miniscrew implants as a result of force application.

Relationship between odontogenic bacteremia and orthodontic stripping.

INTRODUCTION: The aim of this study was to evaluate the prevalence of bacteremia associated with an orthodontic stripping procedure. METHODS: The study included 29 orthodontic patients (mean age, 18.2 ± 3.4 years). We used a standardized stripping procedure: a perforated stripping disk with a contra-angle hand piece was used at a low speed (<15,000 rpm; 10 seconds) on the mandibular anterior teeth. Blood samples were collected by inserting a cannula into the left antecubital fossa. A baseline sample was taken before treatment, and a second sample was taken after the stripping procedure. These samples were inoculated into aerobic and anaerobic blood culture bottles and incubated, and the bacterial cultures were identified; the samples collected before and after the stripping procedure were statistically analyzed. RESULTS: Transient bacteremia was not detected in any pretreatment blood sample, but it was found in 1 postoperative blood sample; this sample tested positive for Streptococcussanguis. CONCLUSIONS: The bacterial species in the positive postoperative blood sample was S sanguis, which might be associated with infective endocarditis. Clinicians should explain the level of risk to the patient and consult a concerned medical specialist.