Differences in third molar development and angulation in class II subdivision malocclusions.

PURPOSE: To assess and compare the developmental stages and angulations of third molars between the class II and class I sides in class II subdivision malocclusions. METHODS: This retrospective study was performed using panoramic x­rays of 38 individuals (mean age: 15.5 years; 24 females, 14 males) with class II subdivision malocclusions, which were further divided into type 1 and 2 subgroups according to midline deviation, and a control group of 42 individuals (mean age: 17.0 years; 30 females, 12 males) with normal occlusion. Third molars were categorized using the developmental stages defined by the Demirjian method. Angles between the third molars and horizontal reference lines and also to the second molars were measured. RESULTS: No difference was found in developmental stages or angulations between the left and right third molars in the control group. In the class II subdivision malocclusion cases, no difference in third molar developmental stages was observed, but the angle between the long axes of the mandibular third and second molars was significantly greater on the class II side. In the type 2 subgroup, developmental stage of the maxillary third molar was more advanced on the class II side. In both subgroups, the angles of the maxillary third molars' long axis to the interorbital plane differed significantly between the two sides. CONCLUSION: Class II subdivision malocclusion may cause differences in third molar development and angulations between the two sides. Orthodontic treatment should be planned considering the third molars in this malocclusion.

Evaluating the changes in nasal airway volume and nasal airflow after surgically assisted rapid maxillary expansion.

OBJECTIVE: This study aims to compare the changes in the nasal airway volume and nasal airflow using acoustic rhinometry (AR), rhinomanometry (RMN), and dental volumetric tomography (DVT) after surgically assisted rapid maxillary expansion (SARME). STUDY DESIGN: Our study consists of 13 adults, 3 male and 10 female patients, aged between 15 and 26, with completed skeletal development. In our study, DVT imaging was obtained twice, preoperation and 3 months after expansion. AR and RMN measurements were recorded, and Visual Analog Score (VAS) and Nasal Obstruction Symptom Evaluation (NOSE) Scale surveys were scored at preoperation and 3 months after expansion. Nasopharyngeal-oropharyngeal airway volume and areas were calculated using the Romexis 3.8.3.R (Planmeca, Helsinki, Finland) and Nemotec V2019 (Madrid, Spain) software programs. IBM SPSS Statistics 22 (SPSS IBM, Armonk, New York) was used for statistical analysis. RESULTS: Comparing the preoperation and postexpansion measurements by both software programs revealed a statistically significant increase in the nasopharyngeal airway volume. No statistically significant change was observed in the oropharyngeal airway volume. Furthermore, we found a statistically significant increase in VAS but a significant decrease in NOSE. CONCLUSION: According to our findings, nasal airway volume increased after SARME, and although there was no significant change in nasal resistance, patients' quality of life increased significantly.

Three-dimensional palatal morphology and upper arch changes following nonsurgical and surgical maxillary expansion in adults.

OBJECTIVE: The objective of this study was to evaluate the effects of nonsurgical rapid maxillary expansion (RME) and surgically assisted RME (SARME) on palatal morphology and upper arch dimensions using three-dimensional (3D) models in skeletally mature patients. STUDY DESIGN: Thirty-eight skeletally mature patients with a maxillary transverse deficiency were divided into RME and SARME groups. Nineteen patients in the RME group (mean age, 19.16 ± 2.25 years) were treated using a full-coverage bonded acrylic splint expander; 19 patients in the SARME group (mean age, 20.38 ± 3.36) were treated using the banded palatal expansion appliance with hyrax screws. The 3D models were obtained before and after expansion. The maxillary dental arch widths, maxillary first molar angulation, palatal area, and palatal volume were calculated on the 3D models. RESULTS: All variables showed statistically significant changes after the retention period (P < .001). The maxillary arch width between first premolars (P < .05), the palatal area (P < .01), and the palatal volume (P < .05) significantly increased in the SARME group compared to the RME group. The maxillary first molar tipping in the RME group was significantly higher than that in the SARME group (P < .01). CONCLUSIONS: Although SARME has more positive effects in skeletally mature patients, nonsurgical RME can be considered as an alternative by evaluating surgical risks, periodontal status, and the need for skeletal expansion.

How much should incisors be decompensated? periodontal bone defects during presurgical orthodontic treatment in class III double-jaw orthognathic surgery patients.

INTRODUCTION: The aims of this study were to evaluate periodontal bone defects around the lower and upper incisors and to identify changes in the buccolingual inclination of the incisors during orthodontic decompensation in skeletal Class III orthognathic surgery patients. MATERIALS AND METHODS: The sample consisted of 26 adults with skeletal Class III deformity who had undergone presurgical orthodontic treatment and orthognathic surgery. Lateral cephalograms obtained before orthodontic treatment and before surgery were used to determine the inclination and position changes of the incisors. Cephalometric measurements were taken using Dolphin Imaging 11.95. Three-dimensional images were generated from cone-beam computed tomography (CBCT) scans prior to surgery and used to detect periodontal bone defects, including fenestration (F) and dehiscence (D). RESULTS: Intraclass correlation coefficients (ICC) were determined and the measurements showed high reproducibility. The cephalometric data showed normal distribution and there were no differences between genders in terms of cephalometric changes, dehiscence, fenestration, or coexistent (D-F/DF) formation. The patients presented maxillary incisor retroclination and mandibular incisor proclination, which was consistent with the tooth decompensation. CBCT assessment was performed for a total of 208 teeth; while 81 upper and 94 lower incisors had D-F/DF formation, 23 upper and 10 lower incisors were healthy. Statistically significant correlations were not found between the inclination degree of the incisors and D-F/DF formation. CONCLUSIONS: Decompensation of incisors during presurgical orthodontic treatment increases the risk of periodontal defects. There is no linear relationship between the increase in the inclination degrees of incisors and D-F/DF formation.

Accuracy of 3 Soft Tissue Prediction Methods After Double-Jaw Orthognathic Surgery in Class III Patients.

PURPOSE: We aimed to evaluate the accuracy and validity of conventional manual prediction method (CM) and 2-dimensional and 3-dimensional (3D) soft tissue prediction methods for Class III bimaxillary orthognathic surgery patients. METHODS: Twenty skeletal Class III patients were included in this study. Soft tissue prediction was achieved with a traditional manual technique, 2-dimensional software (Dolphin Imaging, version 11.5), and 3-dimensional software (SimPlant Master, version 16.0) on preoperative lateral cephalometric radiographs and cone beam computurized tomography (CBCT) images and then compared with postoperative lateral cephalometric radiographs obtained at least 6 months after surgery (mean, 11.5 ± 6.77 months). Forty-eight measurements were done to determine the reliability of the methods. RESULTS: All prediction methods have limited postsurgery prediction accuracy for the subnasal upper lip area. Most of the differences were not more than 3 mm for all study groups, except the 3D software, which predicted the upper lip area to be, on average, 3.08 ± 1.38 mm further back (P < 0.001). Although the conventional method predicted 20 of 48 measurements similar to the final results, the poorest predictions were found at the nasal and labiomental areas (P < 0.001). Two-dimensional software predicted 23 of 48 measurements very close to the final results but made significantly different predictions for the nasolabial and labiomental angles, labrale superius point, and the chin area. CONCLUSIONS: The 3D method predicted, especially the upper lip area, to be significantly and clinically incorrect, and its soft tissue prediction was insufficient compared with the other 2 methods. The 3D software needs to be updated, especially in evaluating soft tissue A point and upper lip changes after surgery.

Use of Laser Systems in Orthodontics.

Laser systems have been used in the practice of dentistry for >35 years. Laser systems have so many advantages, such as increase patient cooperation, reduce the duration of treatment time, and help the orthodontists to enhance the design of a patient's smile to improve treatment efficacy, and the success of orthodontic treatments can also be improved by diminishing the orthodontic pain and the discomfort of the patients. Laser systems also have some disadvantages, such as cost, large space requirements for some types, and high-risk potential for physician and patient if not used at the appropriate wavelength and power density, that is why before incorporating lasers into clinical practice, the physician must fully understand the basic science, safety protocol, and risks associated with them. Lasers have many applications in orthodontics, including accelerating tooth movement, bonding and debonding processes, pain reduction, bone regeneration, etching procedures, increase mini-implant stability, soft tissue procedures (gingivectomy, frenectomy, operculectomy, papilla flattening, uncovering temporary anchorage devices, ablation of aphthous ulcerations, and exposure of impacted teeth), fiberotomy, scanning systems, and welding procedures. In reviewing the literature on the use of laser in orthodontics, many studies have been conducted. The purpose of the present study was to give information about the use of laser in the field of orthodontics, the effects of laser during the postoperative period, and its advantages and disadvantages and to provide general information about the requirements to be considered during the use of laser.

Effects of mesenchymal stem cell transfer on orthodontically induced root resorption and orthodontic tooth movement during orthodontic arch expansion protocols: an experimental study in rats.

OBJECTIVES: The aim was to evaluate the effects of mesenchymal stem cell (MSC) transfer to periodontal ligament (PDL) on the inhibition and/or repair of orthodontically induced root resorption (OIRR) during and after arch expansion and on the orthodontic tooth movement (OTM) rate of the maxillary first molar teeth of rats. MATERIAL AND METHODS: Sixty Wistar rats were divided into three groups as the untreated group, MSC and control injections during the expansion period group (EMSC-EC), and MSC and control injections at the retention period group (RMSC-RC). Fifty grams of orthodontic force was applied to the maxillary first molar teeth of the rats for 14 days in the vestibular direction, and then, 20 days of retention was carried out. MSCs and control injections were performed every 3 days in the EC, RC, EMSC, and RMSC groups. At the end of the experiment, samples were prepared for OTM evaluation, mRNA expression analysis, micro-computed tomography measurements, cementum thickness calculations, and structural examinations. RESULTS: The amount of OTM in EMSC group was significantly higher than in EC group (P < 0.001). MSC transfer during the expansion and retention periods reduced the number of resorption lacunae, volumetric and linear resorptive measurements, and cyclooxygenase-2 and receptor activator of nuclear factor kappa B ligand (RANKL) mRNA expression levels, and increased the osteoprotegerin (OPG) expression levels, OPG/RANKL ratio, and cementum thickness in the EMSC and RMSC groups. CONCLUSIONS: MSC transfer to PDL during expansion increased the amount of OTM. Injection of MSC during the retention period was found to be slightly more effective in prevention and/or repair of OIRR than MSC transfer during the expansion period.

Evaluation of Time-Dependent Temperature Changes during Different Interdental Stripping Procedures by Thermal Imaging: An In Vitro Study.

PURPOSE: To investigate the temperature changes in pulp chamber of incisor and canine teeth during different stripping procedures with thermal imaging. MATERIALS AND METHODS: Intact and freshly extracted human permanent 40 maxillary lateral incisor, 40 mandibular canine and 40 mandibular incisor teeth were selected for this study. Diamond bur, tungsten carbide bur and perforated diamond-coated disc were used for interdental stripping in high and low speed handpieces by air and water cooling. Temperature changes and cooling time of the tooth groups were recorded by a thermal imaging system. Paired t test and one-way analysis of variance (ANOVA) tests were performed for intragroup and intergroup comparisons of temperature changes and cooling time values. RESULTS: Stripping procedures created a statistically significant temperature rise in all study groups (p < 0.05). For maxillary lateral incisors and mandibular incisors, the greatest temperature rise was calculated during stripping with tungsten bur and perforated disk under air cooling (p < 0.001), while no statistically significant difference was found between the temperature rise values of mandibular canine teeth during different stripping procedures (p = 0.053). The lowest temperature rise and cooling time values among all tooth groups were observed during stripping with diamond bur under water cooling and the longest cooling time values were detected during stripping with perforated disc under air cooling (maxillary incisor; p < 0.001, mandibular incisor; p < 0.05, mandibular canine; p < 0.05). CONCLUSION: For all tooth groups, stripping with diamond bur in a high speed handpiece under water cooling produced the lowest temperature rise in the pulp chamber and the shortest cooling time values among different stripping procedures.

Effects of High-Energy Curing Lights on Time-Dependent Temperature Changes of Pulp Space During Orthodontic Bonding.

OBJECTIVE: The purpose of this study was to assess the temperature changes and cooling times during orthodontic bonding by a light-emitting diode (LED) and plasma arc lights (PAC) in different time and power modes with thermal imaging. METHODS: A total of 100 human permanent upper first premolar teeth were included in the study. Five groups were conducted, 20 teeth each, and different energy outputs of curing lights were used for adhesive polymerization with different exposure times. The temperature changes in the pulp space and cooldown times were measured by a thermal imaging system. A paired t-test, analysis of variance (ANOVA), and Student-Newman-Keuls multiple comparison tests were used for data analysis. RESULTS: A statistically significant temperature rise was detected with all curing lights (p<0.05). The greatest temperature changes were observed in the LED standard mode with 10 seconds of exposure time (6.66±1.98°C) and LED extra power mode with 6 seconds of exposure time (6.50±1.64°C) among groups, while using PAC for 3 seconds created the smallest temperature increase (1.81±0.99°C). An application of the LED extra power mode for 6 seconds exhibited the longest cooldown time (205.91±47.48 seconds), and the shortest cooldown time was detected as 71.30±43.15 seconds with the PAC 3-second application. CONCLUSIONS: LED lights with an increased exposure time induced significant temperature rises, while no PAC light group exceeded the critical threshold value. The exposure time is more important than the energy output level of the light-curing system on temperature increments of the pulp chamber.

Changes in pharyngeal airway dimensions following incremental and maximum bite advancement during Herbst-rapid palatal expander appliance therapy in late adolescent and young adult patients: a randomized non-controlled prospective clinical study.

OBJECTIVES: This was a parallel, assessor-blinded, randomized, non-controlled prospective trial with the objective to evaluate and compare the effects of maximum advancement (MA) and incremental advancement (IA) of mandible with cast-splint-type Herbst-rapid palatal expander (RPE) appliance on pharyngeal airway dimensions and hyoid bone position in skeletal Class II late adolescents and young adults. MATERIALS AND METHODS: A total of 48 patients (19 male and 29 female, mean age: 15.45 ± 1.42 years) with skeletal Class II malocclusion were treated with cast-splint Herbst-RPE appliance. Inclusion criteria were skeletal Class II malocclusion, mandibular retrognathia, bilateral Class II molar and canine relationship, increased overjet, normal or decreased vertical dimensions, minimal crowding, and no missing teeth. Enrolled subjects were randomly allocated into two groups according to mandibular advancement type: IA and MA Herbst-RPE therapy. The outcome assessor was blinded. Advancement in MA group was adjusted until tête-à-tête incisor relationship or super Class I molar relationship was obtained. Initial forward movement in IA group was 4-5 mm and followed by bimonthly 2 mm of subsequent advancements. Skeletal, pharyngeal airway, and hyoid measurements were performed using lateral cephalometric films. Statistical significance was set at P value of less than 0.05. RESULTS: Hypopharyngeal airway dimensions (P < 0.000), oropharyngeal airway dimensions (P < 0.001, P < 0.007), and PASmin values (P < 0.010, P < 0.009) were increased and soft palate angle (P < 0.018, P < 0.007) was decreased in MA and IA groups significantly. Hyoid bone measurements revealed a significant difference in H-Cv2 distance (MA: P < 0.002-P < 0.002; IA: P < 0.001-P < 0.043) and H-Cv3 distance (P < 0.005, P < 0.001) for both groups. However, all these changes did not differ among the MA and IA activation groups. ANB°, Wits, overjet, and overbite measurements decreased and SNB°, Co-Gn, Na-Me, ANS-Me, and S-Go increased with the treatment significantly in both mandibular advancement groups (P < 0.000-P < 0.040). CONCLUSIONS: Herbst-RPE appliance provided a similar improvement in the oropharyngeal and hypopharyngeal airway dimensions and similar changes in sagittal and vertical hyoid position for both maximum and IA protocols in patients with skeletal Class II malocclusion. TRIAL REGISTRATION: ISRCTN69743543.

Comparison of dental measurements between conventional plaster models, digital models obtained by impression scanning and plaster model scanning.

OBJECTIVE: Comparison of dental measurements between conventional plaster models, digital models obtained by impression scanning and plaster model scanning. PURPOSE: To evaluate and to compare the accuracy and reliability of tooth size, arch width and Bolton tooth size discrepancy measurements on 3 Dimensional (3D) digital models obtained by plaster dental model scanning, dental impression scanning and conventional plaster models. MATERIAL AND METHODS: This study was carried out on the maxillary and mandibular dental models of 25 patients with Angle Class I molar relationship and minimal crowding. Mesio-distal dimensions of the teeth, intercanine and intermolar arch width, and Bolton tooth size discrepancy measurements were calculated by conventional methods on plaster models, digital methods and on 3D models obtained from plaster model scanning and impression scanning. All measurements were repeated after three weeks for each of the investigated methods. Reliability of measurements was evaluated by Dahlberg formula and Pearson Correlation Coefficient. Comparisons of dental measurements between three methods were achieved with ANOVA Test. RESULTS: The repeated measurements were highly correlated for all methods. Method error was found within clinically acceptable limits. There was no significant difference between dental measurements on plaster dental models, digital models obtained from plaster dental model scanning and dental impression scanning. Results showed the methods being highly reliable and accurate for tooth size, arch width and Bolton analysis at total and anterior proportion calculation. CONCLUSION: Digital measurements of tooth size, arch width and Bolton tooth size discrepancy on digital models obtained from plaster dental model scanning and dental impression scanning showed high accuracy and reliability. There was no significant difference between the three methods for dental measurements.

Effectiveness of incremental vs maximum bite advancement during Herbst appliance therapy in late adolescent and young adult patients.

INTRODUCTION: The purpose of this research was to compare the effects of Herbst appliance therapy using incremental vs maximum advancement in late adolescent and young adult patients with Class II skeletal malocclusion. METHODS: Forty-two patients with skeletal Class II malocclusion were treated with cast-splint Herbst appliances. The subjects were randomly allocated into 2 groups according to activation type: incremental advancement (IA) and maximum advancement (MA). Initial forward movement in the IA group was 4 to 5 mm and was followed by subsequent bimonthly advancements of 2 mm. Single-step advancement was achieved in the MA group until an edge-to-edge incisor relationship or an overcorrected Class I molar relationship was obtained. Total treatment times were 9.7 ± 1.1 months for the IA group and 9.5 ± 1.1 months for the MA group. Dental, skeletal, and soft tissue measurements were performed on lateral cephalograms taken just before and at the end of the Herbst appliance therapy. Statistical significance was set at P ≤ 0.05. RESULTS: All mandibular skeletal dimensions increased, and improvements of the sagittal maxillomandibular parameters were found in both groups. Protrusion and proclination of the mandibular incisors were greater in the IA group (95.90° ± 5.34°) compared with the MA group (92.04° ± 7.92°). Other dentoalveolar changes in both groups were intrusion of the maxillary first molars, and extrusion of the mandibular first molars and maxillary incisors. The mentolabial sulcus was flattened, soft tissue convexity was reduced, and forward movement of mandibular soft tissues was seen after Herbst therapy. CONCLUSIONS: Similar skeletal, dental, and soft tissue changes were obtained in both groups after Herbst therapy. Greater proclination and more protrusion of the mandibular incisors were found in the IA group.

Development of a new three-directional distractor system for the correction of maxillary transverse and sagittal deficiency.

PURPOSE: Class 3 malocclusions with maxillary deficiency, which are treated surgically and/or ordonotically, are common among adult patients. The aim of this study was to develop a three-directional bone-borne distractor that would allow the transverse expansion and sagittal advancement of the maxilla simultaneously. MATERIALS AND METHODS: Computed tomography images of a patient with maxillary deficiency were transmitted to a software program, and a distractor was designed with different sizes (D1, D2, D3) and manufactured from titanium alloy. Y-shape segmental osteotomies were performed on the model, and vertical bite forces were applied. The biomechanical properties were evaluated by using the finite element method. RESULTS: The highest von Mises stress value on the body of the distractor was seen in D2 (D2>D3>D1), with 234 N bite forces. D2 had maximum stress distribution on maxillary bone under 234 N and 93 N (D2>D1>D3). No difference was found among the plastic deformation rates according to biomechanical test results. CONCLUSION: A three-directional bone-borne palatal distractor was produced, and this distractor system can be used for the treatment of skeletal class 3 patients with maxillary hypoplasia for its advantages of shortening the overall treatment time and reducing the scar formation. However, further animal and clinical studies are essential to determine the biological response of soft and hard tissues.

Effects of Photobiomodulation and Ultrasound Applications on Orthodontically Induced Inflammatory Root Resorption; Transcriptional Alterations in OPG, RANKL, Cox-2: An Experimental Study in Rats.

Objective: The aim of this study was to evaluate and compare the reparative and inhibitory effects of a light-emitting diode-mediated photobiomodulation (PBM) and of a low-intensity pulsed ultrasound (LIPUS) on orthodontically induced inflammatory root resorption (OIIRR). Materials and methods: Forty-nine Wistar rats were divided into four groups: untreated group (negative control), group treated with orthodontic appliances (positive control), PBM-treated group (wavelength: 618 nm, output power density: 20 mW/cm2), and LIPUS-treated group (frequency: 1.5% ± 5% MHz, pulse repetition ratio: 1.0% ± 10% kHz, effect area: 3.88% ± 1% cm2 and intensity: 30% ± 30% mW/cm2). OIIRR was induced experimentally in rats for 14 days with an applied force of 100g, and therapeutic approaches were performed concurrently. At the end of the experiment, upper first molar teeth of rats were prepared for genetic analysis, scanning electron microscopy, hematoxylin and eosin staining, and tartrate-resistant acid phosphatase staining. Kruskal-Wallis and post hoc Dunn's tests were performed. Results: Number of osteoclasts (p < 0.01), number of resorption lacunae and resorption area ratio (p < 0.001) decreased and number of total cells (p < 0.001) increased with the PBM and LIPUS applications when compared with the positive control group. Receptor activator of nuclear factor kappa B ligand (RANKL) levels of PBM and LIPUS groups were lower (p < 0.001), and osteoprotegerin (OPG) levels were higher (p < 0.001) than the positive control group. Cyclooxygenase-2 (Cox-2) expression significantly decreased with LIPUS and PBM administrations (p < 0.05). No significant difference was observed among PBM and LIPUS groups. Conclusions: PBM and LIPUS applications showed marked inhibitory and reparative effects on OIIRR by modulating the OPG/RANKL ratio, Cox-2 expression, and cell differentiation of osteoblasts and osteoclasts.

A minimally invasive transfer method of mesenchymal stem cells to the intact periodontal ligament of rat teeth: a preliminary study.

The aim of this study was to introduce a minimally invasive procedure for mesenchymal stem cell (MSC) transfer into the intact periodontal ligament (PDL) of the molar teeth in rats. Ten 12-week-old Wistar albino rats were used for this preliminary study. MSCs were obtained from bones of two animals and were labeled with green fluorescent protein (GFP). Four animals were randomly selected for MSC injection, while 4 animals served as a control group. Samples were prepared for histological analysis, Cox-2 mRNA expression polymerase chain reaction analysis, and fluorescent microscopy evaluation. The number of total cells, number of osteoclastic cells, and Cox-2 mRNA expression levels of the periodontal tissue of teeth were calculated. The number of total cells was increased with MSC injections in PDL significantly (P < 0.001). The number of osteoclastic cells and Cox-2 mRNA expression were found to be similar for the two groups. GFP-labeled MSCs were observed with an expected luminescence on the smear samples of the PDL with transferred MSCs. The results of this preliminary study demonstrate successful evidence of transferring MSCs to intact PDL in a nonsurgical way and offer a minimally invasive procedure for transfer of MSCs to periodontal tissues.

The effects of different desensitizer agents on shear bond strength of orthodontic brackets after home bleaching: an in vitro study.

PURPOSE: The aim of this study was to test the null hypothesis that no difference exists between shear bond strength values of control and bleaching plus desensitizer applied groups. MATERIALS AND METHODS: A hundred freshly extracted human premolar teeth were randomly divided into five groups. Group I served as the control group with no bleaching application, while only bleaching was achieved in Group II. Desensitizer containing potassium nitrate-fluoride and casein phosphopeptide amorphous calcium phosphate were applied in Groups III and IV, after bleaching respectively. A bleaching agent containing amorphous calcium phosphate was used in Group V. Shear bond strength tests were carried out using a universal testing machine (Instron Corp., Norwood, MA, USA). Remnant adhesive on the teeth and brackets was examined to score the adhesive remnant index. Kruskal-Wallis and Chi-Square tests were used for statistical analysis of the data. RESULTS: Statistically significant differences were found among the groups for shear bond strength values (p<.001). The shear bond strength of Group III (8.0±2.2 MPa) was significantly lower than the other groups (p<.05). The highest shear bond strength values were found for Group I (13.6±3.7 MPa) and Group IV (12.8±4.0 MPa). No statistically significant difference was observed between Group II (10.0±2.7 MPa) and Group V (10.8±2.9 MPa). The differences between adhesive remnant index scores of the groups were not statistically significant. CONCLUSION: Casein phosphopeptide amorphous calcium phosphate gel application showed a similar shear bond strength value to the control group, while shear bond strength values decreased after using other desensitizers.

Rate of tooth movement and dentoskeletal effects of rapid canine retraction by dentoalveolar distraction osteogenesis: A prospective study.

INTRODUCTION: The purpose of this study was to test the null hypothesis that duration of orthodontic treatment can be significantly reduced by accelerating canine retraction using dentoalveolar distraction (DAD). METHODS: Thirty-six maxillary canines of 19 patients comprised the DAD group, and 28 canines of 14 patients were included in the distalization group (DG). The initial mean ages were 15.8 ± 1.96 years for the DAD group and 16.02 ± 2.8 years for the DG. A custom-made, rigid, tooth-borne intraoral distraction device was used for the DAD group, and intraoral elastics were applied for canine distalization in the DG. Six skeletal and 11 dental variables were measured for the cephalometric evaluation. RESULTS: Canine retraction was 7.9 ± 1.49 mm in 11.8 ± 1.3 days and canine distal tipping was 11.48° ± 4.37° after DAD; the canines were distalized 5.29 ± 2.01 mm and tipped 13.64° ± 9.54° in 200 ± 57 days in the DG. The rates of posterior canine movement were 0.67 ± 0.14 mm per day after DAD and 0.03 ± 0.01 mm per day in the DG. No significant first molar anchorage loss was observed after DAD, although the DG showed some vertical and sagittal first molar movement. CONCLUSIONS: We failed to reject the null hypothesis. DAD can reduce the duration of orthodontic treatment time by accelerating canine retraction in extraction patients without undesirable side effects.