The Validity of Customized Orthodontic Bracket Set up
Condition: Orthodontic Appliance Complication
Study type: Interventional

Summary: 
      CAD/CAM systems have assisted orthodontists in planning and positioning brackets to minimize
      errors and improve the excellence of treatment. This study aimed to validate measurements
      obtained from manual and digital systems, as well as evaluate the effectiveness, and
      periodontal changes that occurred after the treatment. Materials and Methods: This study is a
      prospective randomized controlled trial, in which clinical evaluation of virtual setup
      (digital and manual) techniques versus CAD/CAM brackets (Ormco© Insignia™ .022" twin
      brackets) in terms of expression of bracket prescription and treatment outcome. The sample
      consisted of 30 young adults with Angle Class I malocclusion. Cone beam computer tomography
      (CBCT) were obtained before and after the treatment to assess the parallelism between the
      dental roots and periodontal conditions. Digital impression by three dimensional (3D)
      intraoral scans (IOS) will be obtained for all participants. The 3D models are converted to
      stereolithography (STL) for all groups. The sample will be dividing randomly into three
      groups; the first one treated with CAD/CAM brackets (Ormco© Insignia™ .022" twin brackets),
      while the other two groups were treated by customization of bracket base of the conventional
      pre-adjusted twin bracket with orthodontic adhesive material, this will be done through
      planning and creating the virtual setup by using Maestro® 3D Ortho Studio software. The
      Indirect bonding devices for the second group will manufacturing from 3D printed models while
      third group from the manual double-layer vacuum-formed thermoplastic trays. All patients will
      treat with fixed orthodontic twin brackets appliances. The 3D models of the Virtual setup are
      comparing with the treated occlusion. The linear and angular measurements are performing by
      the Geomagic® software and using the 3Shape's Ortho-Analyzer TM software in all groups to
      assess the American Board of Orthodontics grading system scores. Random errors are assessing
      by Intra-class Correlation Coefficient (ICC) and method errors. Descriptive statistical
      analysis, Shapiro-Wilk test to detect the normality of variable distribution and the
      Chi-square test evaluated whether the ABO scores measurements are within the limits of
      agreement of each criterion. ABO scores between both groups are analyze by using Wilcoxon
      test. The Bland-Altman analysis evaluated if differences are within the limits of agreement.
    

Detailed description: 
      Introduction Treatment efficiency has become an increasingly important goal of orthodontic
      treatment, yet basic questions about the efficiency of bracket system remain. In contemporary
      preadjusted edgewise orthodontic appliance, the greatest challenge in the success of
      orthodontic therapy depends undoubtedly on the perfection in bracket design, prescription,
      and its positioning in addition to the orthodontist's skill and training. However, due to
      uneven and dissimilar tooth surface anatomy, the need for an accurate method of bracket
      positioning with pre-determined torque and angulation incorporated in the brackets according
      to the patients' need is of key importance.

      Therefore, it is valuable to know, dose digital bracket setting offers better outcomes?
      Previously, indirect bracket positioning technique was done using plaster dental cast where
      kesling setting (teeth alignment) made using the clinical crown. However, recently digital
      technique was used to assess teeth setting and bracket positioning acknowledging root
      positioning using typodonts.

      Null hypothesis:

      There is no difference between the CAD/CAM brackets setting technique (Ormco© Insignia™ .022"
      twin brackets) and virtual (digital and manual) bracket setting technique regarding to
      treatment efficiency and root positioning.

      Aim and Objectives: The aim of the present study is to compare the efficacy of the virtual
      digital / manual setup technique compared to indirect bonded CAD/CAM brackets (Insignia™ twin
      brackets) in terms of expression of bracket prescription and treatment outcome using American
      Board of Orthodontics (ABO) scoring.

      Primary Objectives: The bracket positional accuracy between manual setup-model indirect
      bonding and digital-driven indirect bonding methods.

      Secondary Objectives: Determine the incidence of bracket debonding rate. Methodology Study
      design: This study is a prospective randomized controlled trial, in which clinical evaluation
      of virtual setup (digital and manual) techniques versus CAD/CAM brackets (Ormco© Insignia™
      .022" twin brackets) in terms of expression of bracket prescription and treatment outcome.

      Sample size: All patients will be recruited from the multicenter with one operator. Prior to
      initiating recruitment, a convenient sample size will be recruited. Initially the effect size
      in the sense of Cohen's for the material effect will be determined based on a previous study
      to be about 0.69. It was determined that the current study would reach 0.80% power with a
      total sample size of 54 dental arches, given that the type I error is 0.05.

      Methods: Patients fulfill the selection criteria are recruited at their case presentation
      appointment, and consent form will be obtained. All patients informed to take CBCT before and
      after orthodontic treatment. The 30 consecutive patients (10 in each group) will be divided
      randomly into the virtually digital (Maestro® 3D Ortho Studio software) setup, manual (Ray
      set® device) setup and the CAD/CAM digitally (insignia®) customized group.

      In this study will be use orthodontic adhesive to customize twin brackets base (Discovery,
      Dentaurum, Ispringen, Germany) for both manual and digital (Maestro® 3D Ortho Studio
      software) groups and CAD/CAM brackets (Insignia™ twin brackets) for 3rd group. On the day of
      recruitment, a baseline (T0) three-dimensional (3D) intraoral scan (IOS) will be done for the
      CAD/CAM all groups.

      Manual indirect bonding setups and digital setups will be processed, as will be described in
      the laboratory setting section, for all teeth apart of the second molars according to
      previous study and verified using an objective grading system (OGS) of American Board of
      Orthodontics (ABO), which is currently the gold standard for evaluating plaster casts of
      completed orthodontic cases. In the ABO-OGS, there are eight criteria, seven of which are
      occlusal (tooth alignment, vertical positioning of marginal ridges, overjet, occlusal
      relationship, buccolingual inclination of posterior teeth, occlusal contacts, and
      interproximal contacts) that assess on plaster models to evaluate a patient's final
      occlusion. The remaining last criteria is root angulation measured on CBCT. After setups
      approval, indirect bonding trays or jigs will be constructed and divided randomly to the
      patients. After completion of bonding, an intraoral scanner will be taken to compare the
      bracket positioning.

      Each patient received the same treatment protocol i.e., wire gauges and visiting intervals,
      type of ligation and finishing procedure. At the time of bracket bonding the patients will
      undergo an intraoral scan for the 1st and 2nd group (T1). At the working phase a 0.019*0.25
      stainless steel wire will be inserted for 8 weeks, and the patients will undergo an intraoral
      scan (T2) and sent for CBCT.

      No stopping guidelines will be specified, since subjects were receiving the same treatment
      materials as they would receive as part of standard care of clinical treatment. Bracket types
      will not blind in this study, since clear visual difference exists between the two bonding
      techniques, however, after bonding the treatment will be double blind for person who work on
      the superimposing software and statistician.

      After obtaining all intraoral scans, Best-fit superimpositions will be performed depending on
      palatal rugae, which have been shown to be stable landmarks for the upper arch while in the
      lower arch, second molars (which were not engaged with Arch-wires) are used as stable
      landmarks.

        1. ST GROUP: Manually bracket base customization:

           In the first group of this study, the stone dental cast will undergo to step wise
           procedure in bracket positioning and fabricating an indirect bonding tray for labial
           orthodontics using the Ray set device®:

        2. ND GROUP: Software-driven indirect bonding Set-Up: The dental arch will undergo to a
           digital scanning procedure by intraoral scanner. After scanning, the digital models are
           sending to software-driven bracket placement.

        3. RD GROUP: Insignia TM system:

      The Approver Guide provides a suggested process for reviewing your Insignia cases. Having a
      systematic approach should save time, improve consistency, and help you manage cases more
      efficiently.

      Scanning final Bonded Bracket positions: The final bonded bracket positions will be scanned
      with the intraoral scanner for the 1st and 2nd groups. This scan acquired the exact locations
      of the brackets bonded to the patient's teeth. This acquired image of the final bracket
      position will be superimposed with the initial virtual model in order to compare the bonding
      accuracy of the evaluated methods.

      Superimposition of the digitized models: The STL files of the brackets placed using the
      Maestro® 3D Ortho Studio software will be exported along with the STL files of the scans of
      the brackets bonded intraorally.

      The superimposition process consisted of defining, manually, three points for each model to
      superimpose (tripod), along with a precise automatic system that allowed the alignment and
      superimposition of the selected three points of reference. Lastly, the software will identify
      differences in bracket placement between the two different indirect bonding systems.

      Methods of measurement before and after indirect bonding transfer:

      The Geomagic control X software was used to measure the mesio-distal translation difference
      (in mm), the bucco-lingual translation difference (mm) and the occluso-gingival translation
      difference (mm) between the virtually planned brackets (STL files from the Maestro® 3D Ortho
      Studio software) and the brackets bonded intraorally (STL files from the intraoral scans).
      Each virtually planned bracket will be aligned with the origin of the three-dimensional
      coordinate system at the center-point of an imaginary rectangle constructed on the profile of
      the bracket's four wings and with the z-axis passing through the long axis of the bracket and
      the x-axis passing through the center of the bracket's slot.

      The same method is used for the intraorally scanned brackets, where center-point Zero will be
      maintained as the point of reference. On the two superimposed brackets, the mesio-distal
      translation difference is measured by calculating the distance between the z-axis of the
      virtually planned bracket with a point passing perpendicular to the z-axis of the bracket
      scanned intraorally. In the same way, the occluso-gingival translation difference will be
      measured by calculating the distance between the x-axis of the virtually planned bracket with
      a point passing perpendicular to the x-axis of the bracket scanned intraorally.

      To measure the bucco-lingual difference, the virtually planned bracket will be aligned with
      center-point Zero of an imaginary rectangle constructed on the profile of the two bracket
      wings, with the y-axis perpendicular to the long axis of the bracket, and the x-axis passing
      through the center-point of the rectangle, parallel to the slot base. On the basis of the two
      superimposed brackets, the bucco-lingual difference is measured by calculating the difference
      between the x-axis of the virtually planned bracket and an orthogonal point passing through
      the x-axis of the bracket scanned intraorally.

      Evaluation of mesiodistal tip and labiolingual torque outcomes of manually and virtual-driven
      orthodontic appliances:

        1. A pre-treatment digital model (pre-model) =pre-treatment IOS for clinical crown with
           pre-treatment CBCT scan and a post-treatment digital model (post-model) = post-treatment
           IOS for clinical crown with post treatment CBCT scan of a patient will be retrieved from
           the database.

           The virtual model resulting from the pre-CBCT/pre-model superimposition represents the
           "expected root position" (ERP) setup; it is defined as a prediction of the
           three-dimensional position of the roots after the orthodontic treatment

        2. The virtual model resulting from superimposing and combining the post-CBCT, and the
           post-model represents the "true root position" (TRP) setup, as the post-CBCT depicts the
           three-dimensional position of the roots.

        3. Each tooth isolated from the pre-treatment digital model (pre-model) is individually
           exported using the STL file format, in order to be superimposed independently onto the
           post-treatment digital model (post-model) by using software ''best fit alignment'' to
           overlay the teeth. Color code representing differences between the setup models.

        4. In order to assess the accuracy of the iterative closest point superimposition, color
           maps are generated to visualize the distribution and the extent of the changes occurred
           between ERP and TRP.

        5. The ERP and TRP STL files are then imported into software to calculate angular distances
           between ERP and TRP. Reference landmarks in linear measurements will be identified on
           the root apexes of incisors and canines; the buccal root is evaluated for premolars, the
           palatal root for maxillary molars, and the distal root for lower molars. The center of
           the angle between the root apexes of the ERP and the TRP will be identified on the crown
           of the post-model; it is located on the mesial incisal edge of incisors, on the tip of
           the vestibular cusp of canines and premolars, on the tip of the mesial cusp of maxillary
           molars, and on the tip of the distal cusp of mandibular molars.

      Statistical Analysis:

      Descriptive statistics will be presented, and data distribution will be assessed. Accordingly
      parametric and nonparametric statistics will be used. A P-value of <0.05 will be set to
      define the statistical level. Intra-observer error will calculate using an Intra-class
      Correlation Coefficient (ICC).
    

Intervention name(s): Insignia™ twin brackets; Maestro® 3D Ortho Studio software (Discovery, Dentaurum®, Ispringen, Germany); Ray set® device (Discovery, Dentaurum®, Ispringen, Germany)
Intervention type(s): Device; Device; Device
Intervention description(s): it is metal orthodontic twin brackets with customized base and individual arch-wires for each patient; it is conventional metal orthodontic twin brackets will be customizing the bracket base with adhesive composite, individual arch-wires for each patient and 3D printing indirect bonding tray; it is conventional metal orthodontic twin brackets will be customizing the bracket base with adhesive composite, individual arch-wires for each patient and double-layer vacuum-formed thermoplastic indirect bonding tray
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: digital and manual orthodontic setup; customized orthodontic bracket; indirect bonding tray