Site selection of micro-implant anchorages in the infrazygomatic crest in adult orthodontic patients.

OBJECTIVES: To determine the optimal placement of miniscrews, this study compared adult male and female patients in terms of cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest region. METHODS: The cone beam computed tomography imaging data of 200 patients (20-30 years old; 100 males and 100 females) were collected. The right maxillary posterior teeth in the sagittal plane were divided into six levels from proximal to distal, and three measurement sites were positioned at vertical distances of 8, 10, and 12 mm from the cementum. Cortical bone density, cortical bone thickness, and available bone width were measured in 18 measurement sites in the infrazygomatic crest and analyzed statistically. RESULTS: The highest cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest in adult male and female patients were at the level of the interradicular space between the maxillary second premolar and maxillary first molar. The bone cortical density and thickness increased with vertical height, whereas the available bone width decreased with increasing vertical height. Differences were observed in cortical bone density, cortical bone thickness, and available bone width between adult male and female patients. CONCLUSIONS: The optimal implantation sites of the micro-implant anchorages in the infrazygomatic crest were at the level of the interradicular space between the maxillary second premolar and the maxillary first molar, and the vertical height of the optimal implantation site in males was appropriately higher than that in females.

Retrospective evaluation of the success rate and factors associated with the stability of alveolar ridge orthodontic miniscrews: Pilot study.

BACKGROUND: An uncommon location for placing miniscrews, used to provide anchorage control in various tooth movements, is the alveolar ridge. This study aimed to provide an evaluation of the success rate of alveolar ridge miniscrews and examine variables that might impact their success. METHODS: Charts for 295 patients who had miniscrews were screened. Twenty patients (5 male and 15 female: average age = 38.15 ± 15.10 years) with a total of 50 alveolar ridge miniscrews were analyzed. A customized data form was used to collect patients' and miniscrews' related variables. Kaplan-Meier estimator was used for the survival function, whereas Cox proportional hazards regression models were used to associate collected variables with alveolar ridge miniscrew survival. RESULTS: In total, 31 (62.0%) miniscrews were stable and 19 (38.0%) failed. The survival time for those that failed was 6.03 ± 7.08 months. The follow-up period for those that survived was 35.84 ± 19.47 months. Male gender versus female (hazard ratio [HR] 2.46; 95% confidence interval [CI] 1.35-4.48; P = 0.003), and if the miniscrew was a replacement versus non-replacement (HR 0.27; 95% CI 0.07-0.99; P = 0.048) influenced the survival. Additionally, miniscrews that were used for both indirect and direct or indirect anchorage alone plus those with evidence of splinting showed a 100% survival rate, which led to an HR 0 (P < 0.001). When the previously mentioned variables were modeled, none seemed to have a significant effect on failure except for splinting and type of anchorage (P < 0.001), because none of the splinted miniscrews failed. CONCLUSIONS: The failure rate of alveolar ridge miniscrews was (38.0%) over 6.03 ± 7.08 months. The survival rate was (62.0%) over 35.84 ± 19.47 months. The evidence of splinting and the type of anchorage had a significant effect on survival probability.

Influence of the Curve of Spee on Tooth Displacement Patterns: A Finite Element Analysis at Varying Implant Heights.

Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

Surface Treatment of Dental Mini-Sized Implants and Screws: A Systematic Review with Meta-Analysis.

Miniscrews are devices that allow for absolute skeletal anchorage. However, their use has a higher failure rate (10-30%) than dental implants (10%). To overcome these flaws, chemical and/or mechanical treatment of the surface of miniscrews has been suggested. There is no consensus in the current literature about which of these methods is the gold standard; thus, our objective was to carry out a systematic review and meta-analysis of the literature on surface treatments of miniscrews. The review protocol was registered (PROSPERO CRD42023408011) and is in accordance with the PRISMA guidelines. A bibliographic search was carried out on PubMed via MEDLINE, Cochrane Library, Embase and Web of Science. The initial search of the databases yielded 1684 results, with 98 studies included in the review, with one article originating from the search in the bibliographic references of the included studies. The results of this systematic review show that the protocols of miniscrew surface treatments, such as acid-etching; sandblasting, large-grit and acid-etching; photofunctionalization with ultraviolet light; and photobiomodulation, can increase stability and the success of orthodontic treatment. The meta-analysis revealed that the treatment with the highest removal torque is SLA, followed by acid-etching. On the other hand, techniques such as oxidative anodization, anodization with pre-calcification and heat treatment, as well as deposition of chemical compounds, require further investigation to confirm their effectiveness.

Clinical Evaluation of Single Versus Repeated Micro-Osteoperforations During Orthodontic Canine Retraction: A Randomized Clinical Trial.

INTRODUCTION: In the majority of orthodontic premolar extraction cases, the canine retraction phase is the most laborious procedure. This randomized clinical trial aimed to assess the effect of single versus repeated micro-osteoperforations (MOPs) during orthodontic canine retraction. METHODS: In this split-mouth study, two equal groups of 18 patients who required maxillary first premolar extractions and fixed orthodontic therapy were randomly assigned (n=9). In Group I, MOPs were only performed once on one site before retraction, whereas in Group II, MOPs were performed on one site repeatedly once a month for four months. In both groups, the contralateral control sites received no MOPs. The canines were retracted using mini-screws and closed-coil nickel-titanium springs. Using the patients' 3D models, the primary outcome measure at four months was the amount of orthodontic canine distal movement. The amount of anchorage loss (AL), degree of molar rotation (MR) and canine rotation (CR), and degree of canine tipping (CT) were measured as the secondary outcomes. The comparison of mean changes in the primary and secondary outcomes between the groups was done using the independent sample t-test (p<0.05). RESULTS: The rate of canine retraction, degree of CT, and rotation were not significantly different between the two groups (p>0.05). Additionally, there were no statistically significant variations in the maxillary first MR and the degree of AL (p>0.05). CONCLUSIONS: When maxillary canine retraction was performed with a single and repeated regimen of MOPs, comparable levels of distal CR and tipping were observed, along with an identical minimal degree of MR and AL.

Reliability and safety of miniscrew insertion planning with the use of lateral cephalograms assessed on corresponding cone-beam computer tomography images.

BACKGROUND/OBJECTIVES: Recently, lateral cephalograms have been proposed for guided miniscrew insertion planning. Therefore, the aim was to assess the reliability and safety of such planning on corresponding cone-beam computer tomography (CBCT) images. MATERIALS/METHODS: Intraoral scans, lateral cephalograms, and CBCT images of 52 subjects (even sexes distribution), aged 15.1 ±â€…2.5 years, were included. Miniscrew (n = 104) insertion planning was performed using lateral cephalograms superimposed on the maxillary intraoral scans, while the assessment of their bicortical placement, length in bone, contact with adjacent teeth, incisive canal, and nasal floor perforation was done on corresponding superimposed CBCT images. Moreover, maxillary incisor inclination, crowding, and the maxillary intercanine width were measured. RESULTS: The overall miniscrew length in bone was 7.2 ±â€…1.3mm. Bicortical placement was seen in 58.7% of the sample (38.5% of subjects). Incisive canal and nasal floor perforation was seen in 25% and 21.2% of subjects, respectively. No contact of the miniscrew with adjacent teeth was recorded. A negative significant interaction was seen between the miniscrew length in bone, the percentage of total miniscrew length and maxillary anterior teeth crowding (ß, -0.10, P = .047 and ß, -0.90, P = .006, respectively). Moreover, a positive significant interaction was seen between the incisive canal perforation and maxillary anterior teeth crowding (OR = 1.32, P = .021). LIMITATIONS: Exclusion of subjects with impacted teeth. CONCLUSIONS: Miniscrew insertion planning using lateral cephalograms, despite being safe in preventing contact with adjacent teeth, is limited in achieving bicortical placement and insufficient in completely avoiding incisive canal and nasal floor perforation.

Usage of temporary anchorage devices: A cross-cultural and cross-sectional survey of orthodontists in Australia and the UK.

INTRODUCTION: Detailed insight regarding the use of temporary anchorage devices (TAD) in Australia and the United Kingdom (UK) is lacking. The primary aim of the present cross-sectional survey was to investigate TAD usage among UK-based and Australian-based orthodontists. The secondary objectives were to compare TAD-related preferences and protocols between orthodontists in the two countries. METHODS: A pilot-tested electronic questionnaire was distributed to members of the British Orthodontic Society and the Australian Society of Orthodontists. Questions pertained to their demographic details, and current use of TADs including protocols, treatment objectives and factors influencing their use. RESULTS: A total of 192 responses were recorded (Australia: 122; UK: 70). One hundred and forty-two respondents (74.0%) reported using TADs as part of their orthodontic treatment, 77.0% in Australia (n=94) and 68.6% in the UK (n=48). Molar protraction was the most common procedure for which TADs were reportedly used (Australia: n=118; 87.2%, UK: n=36; 75.0%). "Loosening" was the most prevalent reported complication overall (n=124; 90.1%). "Confidence", "insufficient postgraduate education" and "availability of equipment" were the factors that most influenced the decision not to provide TADs. CONCLUSIONS: Most orthodontists in both countries provided TADs. TAD protocols of orthodontists in both countries were reported. Similarities and differences regarding TAD-related clinical practices and procedures, complications and factors influencing the use of TADs and reasons for not using TADs were explored. Information from the present study can provide baseline data for future related studies in each country and for comparison of TAD usage in other countries.

Cephalometric and digital model analysis of dentoskeletal effects of infrazygomatic miniscrew vs. Essix- anchored Carriere Motion appliance for distalization of maxillary buccal segment: a randomized clinical trial.

TRIAL DESIGN: Parallel. OBJECTIVE: To compare skeletally anchored Carriere Motion appliance (CMA) for distalization of the maxillary buccal segment vs. Essix anchored CMA. METHODS: Thirty-two class II malocclusion patients were randomly allocated into two equal groups. One group was treated with infrazygomatic (IZC) miniscrew- anchored CMA (IZCG) and the other group treated with Essix retainer- anchored CMA (EXG). Two lateral cephalograms and two digital models for upper and lower arches were taken for each patient: immediately before intervention and after distalization had been completed. RESULTS: Distalization period was not significantly different between the two groups. In contrast to EXG, IZCG showed insignificant difference in ANB, lower incisor proclination, and mesial movement of the lower first molar. There was significant rotation with distal movement of maxillary canine and first molar in both groups. CONCLUSION: IZC anchored CMA could eliminate the side effects of class II elastics regarding lower incisor proclination, mesial movement lower molars with a more significant amount of distalization of the maxillary buccal segment but with significant molar rotation. TRIAL REGISTRATION: The ClinicalTrials.gov Protocol Registration and Results System (PRS) has this RCT registered as (NCT05499221) on 12/08/2022.

Adult female skeletal anterior open bite treated by customized lingual orthodontic appliance with miniscrews-assisted in vertical control for perfect orthodontic compensation: A case report with 5-year follow-up.

The benefits of lingual orthodontics go beyond appearance. In this case study, a 30-year-old female patient was treated with a custom lingual orthodontic appliance for a Class II high-angle malocclusion, anterior open bite, incisor biprotrusion and crossbite, unilateral second molar scissor bite and dysfunctional tongue thrust. To achieve a counterclockwise rotation of the mandible, implant anchorage was used to control the vertical height. To complete the compensatory therapy, four first premolars were removed. As well as ensuring aesthetics over the 20-month treatment period, the treatment also established a Class I molar relationship, normal overbite and overjet, and improved the facial profile. After a five-year follow-up, the treatment results remained stable.

Histomorphometric and CBCT comparison of osseointegration around orthodontic titanium miniscrews coated with different nanoparticles: An in-vivo animal study.

BACKGROUND: Temporarily installed titanium orthodontic miniscrews are usually used for many orthodontic applications, especially those cases that need high force, such as skeletally anchored orthodontic appliance cases. Surface modification of titanium miniscrews has proved success in preventing failure and overcoming their limitations. OBJECTIVE: The present study aims at the assessment of the quality of osseointegration of surface modified titanium miniscrews installed in the maxilla of albino rabbits with cone-beam computed tomography (CBCT) imaging as well as histomorphometric investigations. MATERIAL AND METHODS: The orthodontic titanium miniscrews (TMSs) were coated with silver/hydroxyapatite (Ag/HA) nanoparticles (NPs) or zinc oxide (ZnO) NPs via electrochemical deposition. The coating nanomaterials were then characterized with X-ray diffractometry (XRD) and scanning electron microscopy (SEM) imaging. Moreover, the antimicrobial activity of the coated titanium miniscrews were evaluated in the rabbits' oral cavity to investigate their ability to prevent biofilm formation. RESULTS: It was found that the Ag/HA-coated TMSs demonstrated the highest antimicrobial activity and bone area fill, followed by the ZnO NPs-coated TMSs when compared to their uncoated counterparts. In the anterior area surrounding the installed TMSs, the highest osseointegration was demonstrated by ZnO NPs-coated TMSs. However, Ag/HA-coated TMSs showed the highest osseointegration values in the posterior peri-implant area. CONCLUSIONS: Ag/HA- and ZnO NPs-coated TMSs may provide a promising solution to overcome the 30% probable failure in temporarily installed orthodontic miniscrews, as they can enhance the osseointegration process and prevent biofilm formation.

A 3D Finite Element Analysis of biomechanical effects on teeth and bone during true intrusion of posteriors using miniscrews.

OBJECTIVE: The primary objective of this study was to investigate the biomechanical effects and stresses on bone, PDL, cementum and displacement along X-,Y- and Z-axis during true intrusion of molars using mini-implants with finite element analysis; the secondary objective of the study was to find out the best method for posterior intrusion in clinical practice. MATERIAL AND METHODS: A 3D finite element method was used to simulate true molar intrusion using sliding mechanics. Two groups were made, with mini-implants placed on buccal side and palatal side with a cap splint for MODEL1, and a single mini-implant placed buccally with transpalatal arch (TPA) for MODEL2. The material characteristics which include the Young's modulus and Poison's ratio were assigned. von Mises stress, principal stress on PDL and alveolar bone, displacements in all the 3 planes were determined. RESULTS: Bone stress patterns showed compressive stresses on the buccal aspect and tensile stresses on the palatal aspect for both MODELS. Stresses in the PDL and cementum were mainly concentrated in the apex region, with a more uniform distribution of stresses for MODEL 1. Tooth displacement showed true intrusion for both MODELS, i.e. the Z axis, and a more controlled buccal tipping for MODEL 1. CONCLUSION: Of the modalities compared, the best controlled tooth movements for posterior intrusion in the treatment of open bite were obtained with mini-implants placed with a cap splint (MODEL 1).

Evaluation of mechanical properties and morphology of miniscrews Ti6Al4V cold worked versus annealed in artificial bones.

PURPOSE: This study aimed to evaluate the influence of different manufacturing procedures (Eli annealed - hot work versus cold worked - cold work) of the raw material under mechanical properties and morphological characteristics of orthodontic miniscrews (MS). MATERIAL AND METHODS: Thirty MS were randomly separated into 3 types (n=10) according to manufacturer and manufacturing process of the raw material: type A - SIN® annealed (control group); type B - Dentfix® annealed; and, type C - Dentfix® cold worked. MI were inserted in artificial bone blocks, through the manufacturer's specific manual key attached to the digital torquemeter stabilized via custom device. Data of fracture's occurrence was performed using Fisher's exact test. Comparisons between the other two types regarding insertion torque and removal torque were performed using the Mann-Whitney test. Data of fracture torque, shear stress, normal stress and torque ratio was submitted to Kruskal Wallis and Dunn tests (α=0.05). Representative images of surface morphology and fractures were selected. RESULTS: Type C showed statistically the lowest fracture torque (N.cm) (26.11±0.41) (P=0.0012) and highest torque ratio (%) (98.74±0.85) (P=0.0007). Type C showed statistically higher calculated shear (MPa) (2,432.73±508.41) and normal stress (MPa) (1,403.86±293.39) than type B and type A, showing that they differed in relation to the mechanical strength of the material with which they were made (P=0.0007). CONCLUSION: Type A fractured completely inside the most apical bone. Type B and type C fractured closer to the transmucosal profile. Cold worked process should be more prone to fractures than those annealed raw manufactured.

Comprehensive orthodontic treatment using miniscrews and digital rehabilitation in a patient with severe recessive dystrophic epidermolysis bullosa.

INTRODUCTION: Epidermolysis bullosa (EB) is a rare genetic disorder characterized by skin fragility and blister formation. The phenotypic presentation is broad with four major types, being Recessive Dystrophic EB (RDEB) the most severe, including oral anomalies such as severe microstomia, ankyloglossia, vestibule obliteration and occlusal anomalies, turning orthodontic treatment into a challenge. AIM: This case report aims to present the comprehensive treatment of a patient with severe RDEB, including periodontal surgery, orthodontic fixed braces with mini-screws and oral rehabilitation with anterior veneers. CASE REPORT: A 27-year-old female patient with severe RDEB received orthodontic treatment in the upper jaw to improve malalignment and anterior crossbite. After 13 months of treatment with fixed appliances, miniscrews were placed in the anterior segment to intrude and procline the upper incisors. Oral surgery was performed to increase the vestibule depth of the upper lip. Once edge-to-edge occlusion was obtained, anterior veneers were placed to improve aesthetic and stabilize occlusion, especially with the lack of posterior support. DISCUSSION: The multidisciplinary treatment approach, involving orthodontic treatment, periodontal surgery and oral rehabilitation, played a crucial role in achieving favorable results. This case highlights the successful use of miniscrews as a viable orthodontic approach for patients with severe RDEB.

Three-dimensional evaluation of the cortical and cancellous bone density and thickness for miniscrew insertion: a CBCT study of interradicular area of adults with different facial growth pattern.

AIM: The purpose of this study was to evaluate the effect of the density and the thickness of the cortical and the cancellous bone at selected inter-radicular areas in subjects with different facial growth patterns using cone beam computed tomography (CBCT) in order to choose the optimal area for miniscrew insertion. MATERIALS AND METHODS: From 150 CBCT scans, 45 scans were included in the study. The subjects were categorized into three groups based on their skeletal growth pattern according to SN-GoMe angle and facial height index. Cortical and cancellous bone density and thickness were measured at the selected inter-radicular areas. RESULTS: Compared to the other two groups, the hyperdivergent group had thinner cortical bone in the anterior region of the maxilla between the central and the lateral incisors on the buccal side at 4 mm from the alveolar crest (P-value: 0.012) and on the palatal side at 7 mm from the alveolar crest (P-value: 0.030). Cancellous bone density values in these areas were higher in subjects with hypodivergent and hyperdivergent growth pattern. Furthermore, in hyperdivergent group less dense cortical bone in the posterior region of the maxilla on the palatal side between the second premolar and the first molar (p-value: 0.020) and on the buccal side between the first molar and the second molar (p-value: 0.038 & 0.047) was observed. No significant differences were found in the mandible between the three groups. No significant differences were found between the male and the female subjects. CONCLUSION: Hyperdivegents presented thinner cortical bone in the anterior of the maxilla between the central and the lateral incisors. Less dense cortical bone was found between maxillary second premolar and first molar on the palatal side and also between the maxillary first molar and the second molar on the buccal side in this group too. Normal showed higher density values in the posterior of the maxilla compared to the other two groups. No significant differences were found among three groups in mandible.

Comparative analysis of anchorage strength and histomorphometric changes after implantation of miniscrews in adults and adolescents: an experimental study in Beagles.

OBJECTIVES: This study aimed to explore the differences in anchorage strength and histomorphometric changes in orthodontic miniscrews between adult and adolescent beagles. MATERIAL AND METHOD: Six adult beagles and six young beagles were used as experimental subjects, and eight miniscrews were symmetrically placed in the posterior mandible of each dog. Measurement of the displacement (mm) of two adjacent miniscrews after load application was performed to compare the anchorage strength between the adult and adolescent groups. Three intravital bone fluorochromes (oxytetracycline, calcein green, xylenol orange) were administered postoperatively to mark the active bone-forming surface. Subsequently, the mineral apposition rate and bone-implant contact ratio were measured for dynamic and static histomorphometry. Finally, the expression levels of the RANKL/OPG ratio were evaluated by immunohistochemistry. RESULTS: The average displacement of miniscrews in the adult group was significantly less than that in the adolescent group after load application. For histomorphometry analysis, the mineral exposure rate in the adolescent group was higher than that in the adult group with or without force application. In addition, more fractures and new bone formation but deceased bone-implant contact ratios were observed in the adolescent group than in the adult group. The ratio of RANKL/OPG expression increased more in the adolescent group than in the adult group. CONCLUSION: Miniscrews do not remain in the same position as skeletal anchors, and the amount of displacement was higher in adolescent group than that in adult group, reflecting the weaker anchorage strength of miniscrews in adolescents due to the higher bone turnover rate and active bone remodelling. Therefore, it is feasible to apply orthodontic loading to the miniscrews in adult patients earlier, even immediately, but it is recommended to wait a period for the adolescents.

Skeletal and dentoalveolar changes after total maxillary arch distalization using the casted palatal plate vs. buccal miniscrews: A randomized clinical trial.

OBJECTIVES: To evaluate treatment changes after total maxillary arch distalization using the casted palatal plate compared with buccal miniscrews. MATERIAL AND METHODS: This was a randomized, parallel, two-arm, single center trial. Participants were young adults with class II dental relationships and normal or horizontal growth patterns. The patients were treated with total distalization of the maxillary arch and were randomly allocated, according to the anchorage devices, between the plate group and the minivis group. The primary outcomes were sagittal, vertical and angular changes of molars and incisors, while the secondary outcomes were skeletal and soft tissue changes. Outcomes were evaluated on lateral cephalograms and blinding of outcome assessment was implemented. A multivariate analysis of Variance (MANOVA) tests were used and Bonferroni correction for multiple comparisons with P<0.001. RESULTS: Forty patients (33 females and 7 males; mean age 20±3.1 years) where enrolled. A significant distalization of U6 was observed in both groups (4.33mm in the plate group and 1.88mm in the miniscrews group). It was combined with significant intrusion and non-significant distal tipping of the U6 in the plate group (1.85mm and 3.10°, respectively), while intrusion and distal tipping were non-significant in the miniscrew group (0.8mm and 2°, respectively). Both groups showed significant retraction and palatal inclination without vertical changes of U1. Only the plate group produced significant reduction of ANB and Wits. Upper and lower lips were retracted and the nasolabial angle increased significantly in both groups. There was no significant main effect of the appliance type on the comparison of treatment effects between the two groups (P=0.623). However, univariate comparisons showed that the plaque group showed greater distalization of the U6 (P<0.001). CONCLUSIONS: Both the casted palatal plate and buccal miniscrews can be viable devices for total distalization of the maxillary arch in the treatment of class II patients. The casted plate may be considered when more extensive distalization is required.

Evaluation of Patient-Centered Outcomes Associated With the Acceleration of en-Masse Retraction of Upper Anterior Teeth Assisted by Flapless Corticotomy Compared to Traditional Corticotomy: A Two-Arm Randomized Controlled Trial.

OBJECTIVE: This study aimed to assess the levels of pain, discomfort, and functional impairment associated with the en-masse retraction of the upper anterior teeth when treating Class II division 1 malocclusion patients using traditional corticotomy or flapless corticotomy. In addition, an assessment of patients' satisfaction with the selected surgical intervention was undertaken at one-month post-operatively. MATERIALS AND METHODS: The study sample comprised 40 patients with Class II division 1 malocclusion, randomly assigned to either the traditional corticotomy group (n=20) or the flapless corticotomy group (n=20). Patients underwent extraction of the maxillary first premolars, and orthodontic mini-screws were placed between the maxillary second premolars and the first molars for skeletal anchorage. An en-masse retraction was accomplished in both groups. Patients were asked to fill in a questionnaire at 24 hours (T1), four days (T2), seven days (T3), 14 days (T4), and 28 days (T5) after the surgical intervention using standardized questionnaires. Most questions were answered on a visual analog scale where zero scores meant the absence of pain, discomfort, or functional impairment, and 100 scores meant the worst feelings of these traits. RESULTS: All patients in both groups entered data analysis with no dropouts. All measured levels were significantly greater in the traditional corticotomy group during the first two weeks following the corticotomy intervention in terms of pain perception (P˂0.001), discomfort (P=0.004), and difficulty in chewing (P=0.015). Additionally, during the first week following corticotomy, levels of perception of discomfort (P˂0.001), difficulty in swallowing (P=0.001), and limitation of jaw movement (P˂0.001) were significantly greater in the traditional corticotomy group. Patient satisfaction, the recommendation to a friend, and acceptance of flapless corticotomy were significantly greater than traditional corticotomy (P=0.002, P=0.001, respectively). 78% of patients in the traditional corticotomy group considered it more discomfort than a tooth extraction, while 50% of patients in the flapless corticotomy group considered tooth extraction more discomfort, with a significant difference between the two groups (P=0.001). CONCLUSIONS: The levels of negative patients' reported outcomes were significantly smaller with flapless corticotomy than with traditional corticotomy. Traditional corticotomy was associated with mild to moderate levels of pain, swallowing difficulty, moderate levels of discomfort, chewing difficulty, and jaw movement limitation after 24 hours of the surgical procedure. In contrast, flapless corticotomy was less problematic and associated with mild pain, swelling, chewing difficulty, jaw movement limitation, and swallowing difficulty at the same assessment time. Patient satisfaction, acceptance, and recommendation to a friend were greater for flapless corticotomy than traditional intervention.

Alveolar Bone Microstructure Surrounding Orthodontic Anchor Screws with Plasma Surface Treatment in Rats.

A lateral load was applied to anchor screws that had undergone surface treatment, and the structure, cellular dynamics, and quality of the bone surrounding anchor screws were analyzed to investigate the effect of this surface treatment on the peri-implant jawbone. In addition, bone microstructural characteristics were quantitatively evaluated for each site of loading on the bone around the anchor screw. Rats were euthanized after observation on days 3, 5, or 7, and bone quality analyses were performed. Bone-implant contact rate increased more rapidly at an early stage in the treated surface group than in the untreated surface group. Bone lacuna morphometry showed that the measured values adjacent to the screw at the screw neck on the compressed side (A) and at the screw tip on the uncompressed side (D) were significantly lower than those at the screw tip on the compressed side (B) and at the screw neck on the uncompressed side (C). Collagen fiber bundle diameter showed that the measured values adjacent to regions A and D were significantly higher than those at regions B and C. Anchor screw surface activation facilitates initial bone contact of the screw, suggesting that early loading may be possible in clinical practice.

Comparison of mechanical stability of mini-screws with resorbable blasting media and micro-arc oxidation surface treatments under orthodontic forces: An in vitro biomechanical study.

INTRODUCTION: The aim of this study was to compare the primary stability of mini-screws with different surface treatments such as resorbable blasting media (RBM) and micro-arc oxidation (MAO) under in vitro orthodontic forces. MATERIAL AND METHODS: Thirty-six self-drilling TiAl6V4-ELI grade 23 titanium alloy 1.6×8mm mini-screws were inserted into polyurethane foam blocks and divided into three groups according to surface properties: machine surface (MS), RBM-treated, and MAO-treated. An orthodontic force of 150g was applied to the mini-screws using NiTi coils. Maximum insertion torque (MIT) and maximum removal torque (MRT) were measured with a digital torque screwdriver during insertion and removal. For each mini-screw, stability measurements were made with the Periotest M device at day 0 and weeks 1, 2, 4, 8, and 12. RESULTS: Significant differences in MIT were observed between all groups in pairwise comparisons (P<0.001) with the highest value in the MAO-treated group and the lowest in the MS group. The mean MRT values differed in all three groups (P=0.001). In pairwise comparisons of MRT, only the difference between MS group and RBM-treated group was significant. The highest value was observed in the RBM-treated group, while the lowest value was observed in the MS group. Periotest values were significantly higher in the MAO-treated group than the RBM-treated group at weeks 8 and 12. A positive significant correlation was found between MIT and MRT in all groups. No significant correlation was found between MIT, MRT and Periotest values in all groups. CONCLUSION: RBM-treated group was significantly higher than the MS group in MIT and MRT values. According to Periotest values, RBM-treated group was found to be significantly more stable than the MAO-treated group at weeks 8 and 12. Therefore, RBM surface treatment was found to be more favourable than other surfaces to increase success rate in clinical applications.