Comparison of the Accuracy and Reliability of Measurements Made on CBCT and IOS Images With Their made-on Plaster Models.
Condition: Malocclusion
MeSH terms: Malocclusion
Study type: Observational [Patient Registry]

Summary: 
      The orthodontist uses plaster models to collect information. This includes identification
      deviations, classification of malocclusion, formulation of treatment goals for specific
      patient. Models are used to examine the morphology of individual teeth and also to visualize
      the placement of teeth in individual dental arches. Study models It therefore appears to be
      one of the most important records for treatment planning.

      In USA, orthodontist can start practicing orthodontics which requires a lot of difficulty 300
      new cases in a year and therefore may require an entire room to store plaster models. The
      minimum file retention period depends on the appropriate platform for the statute of
      limitations during which legal action for fault can be brought. in the USA, this time period
      varies from 5 to 15 years, varies from country to country.

      This platform can be started on the last day of treatment, or it can be postponed until the
      patient reaches adulthood. Regardless of how it is viewed, long term storage is required.
      Over ten years, if 300 new cases are initiated each year, that will represent 6,000
      combinations of prototyping, pre-processing and post-processing. Additional storage space may
      be required, maybe somewhere else, with financial implications.

      With the recent introduction of digital models and CBCT images, the orthodontist now has an
      alternative to traditional plaster study models. Digital technology makes it possible to
      analyze a computer using software capable of rotating, examining and measuring digital images
      of the model and dental arches from different points of view. The intraoral scanner is a
      hand-held device that creates digital impressions of the oral fossa and displays it in 3D on
      a computer screen after being processed by the scanning program for each device. By 1985 the
      first intraoral scanner was available for commercial use, and over time it had evolved to
      become smaller, faster, and more accurate. Intraoral scanners provide easier treatment
      planning, better workflow, greater patient acceptance and shorter working time, but more
      studies are needed to investigate their accuracy and compare with traditional methods. The
      measurements of the tooth widths are one of the important elements in orthodontic diagnosis
      because of its role in calculating the partial and total Bolton ratio, the Ton relationship,
      and space analysis. Therefore, the aim of this study will be to assess the accuracy and
      reliability of measuring teeth widths and Bolton ratios based on three mains well -known
      methods (plaster models, CBCT images and intraoral images) to ensure the safety of
      orthodontic diagnostic outputs.
    

Detailed description: 
      Several published studies analyzed teeth widths and Bolton' ratios using CBCT with plaster
      models, two-dimensional images, or three-dimensional images as the gold standard and applied
      to patients or skulls, but they did not use the sagittal axis orientation method for each
      tooth on the limit to determine its precise lateral mesial width, but the method of unified
      orientation was adopted in the transverse plane.

      The most important benefit of the CBCT is that the measurements are made directly on the
      digital model, which eliminates the possibility of error that can occur with traditional
      methods (alginate blending, alginate hardening, casting) or some other digital methods (such
      as scanning plaster model).

      The special orientation method was adopted for each tooth separately so that the three axes
      of the software are perpendicular to the longitudinal axis of the tooth, and the maximum
      mesio-lateral width is determined on both the axial plane and the transverse plane, and the
      measurement is made on each of them, which is supposed to be identical in the case of correct
      orientation.

      This method is useful for determining the width of each tooth, regardless of its position
      within the dental arch or overlapping it with other teeth.

      The intraoral scan is the latest innovation in dentistry to generate three-dimensional models
      that can be studied, and many tests were conducted on it to determine its accuracy and
      reliability by determining teeth widths and the Bolton ratios with the adoption of plaster
      models or two-dimensional images as a gold standard.

      Looking at the published medical literature, and in an attempt to find a study similar to the
      current study, It was found that the comparisons regarding teeth widths measurements were
      among plaster models (as a gold standard) and CBCT images or between plaster models (as a
      gold standard) and IOS images, and no study was found that made a comparison Triple among the
      previous three methods.
    

Intervention name(s): Plaster models; CBCT images; IOS images
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): The impressions taken of the dental arches will be poured with hard gypsum in order to make use of the models for taking measurements. These measurements will be considered the gold standard.; All patients have been undergoing CBCT scans for both jaws; The patient's teeth have been dried with air syringe and scanned with the Intraoral scanner
Other intervention name(s): Study models; Study casts; Poured study models; cone beam computed tomography images.; intra oral scanner images
Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        Patients with different levels of malocclusion
      
Keywords: plaster model; cone beam computed tomography.; intraoral scanner; teeth widths; Bolton' ratios.; CBCT; IOS