The Effect of Expansion on Craniofacial Sutures in Children Using 3D Imaging
Condition: Skeletal Maxillary Transverse Deficiency
Study type: Observational

Summary: 
      The aim of this study to test the immediate effect of rapid maxillary expansion on
      craniofacial sutures in children using cone beam computed tomography.

      Materials and Methods: Subjects consisted of 15 growing patients between the ages of 8 and 12
      with Skeletal transverse maxillary deficiency with unilateral or bilateral posterior cross
      bite.

      All patients will be treated with A bonded Hyrax (a rapid palatal expander with an acrylic
      occlusal splint). The planned activation protocol consisted of 2 turns per day (0.25 mm per
      turn) until the resolution of posterior cross bite with 2 to 3 mm overcorrection of expansion
      then tying off the jackscrew with a ligature wire and placing a smooth composite material
      over it. The initial CBCT scan (T0) will be taken before cementation of the maxillary
      expander and again immediately after the end of the active expansion (T1). First, all CBCT
      images will be oriented then the craniofacial sutures(Intermaxillary Suture, Midpalatal
      Suture, Transpalatal Suture, Internasal Suture, Frontonasal suture, Zygomaticotemporal
      suture, Frontomaxillary suture, Zygomaticomaxillary suture, Nasomaxillary sutures,
      Spheno-occipital synchondrosis) will be examined. Where the linear measurements will be
      carried out directly on the CBCT image using the OnDemand 3D Imaging software program.
    

Detailed description: 
      Rapid maxillary expansion (RME) treatment has been used widely since the mid 1960s. It is
      frequently used to correct maxillary width deficiency, posterior crossbite or to expand arch
      perimeters to alleviate dental crowding or patients with Class III malocclusion who often are
      treated with RME because of an insufficient maxillary arch width. Although, the major effect
      of this treatment is noticed clinically in the dentition and maxilla area. RME therapy
      appears to involve an ample portion of the craniofacial complex, as the maxilla is associated
      with 10 bones in the face and head. Although, the RME force is concentrated on widening the
      maxilla, concomitant changes occur in circumaxillary sutures. Moreover, it has been claimed
      that the transverse forces generated during rapid maxillary expansion are transmitted, via
      the pterygomaxillary connection, to the unpaired sphenoid bone of the cranial base, where
      they lead to stress. The extent and effects of this have not yet been studied extensively,
      nor have they been well determined. In orthodontics, the cranial base has received attention
      because of the fact that its growth influences the maxillary-mandibular complex. Some authors
      in fact consider the cranial base as a guide rail for development of the maxilla, midface,
      and lower facial complex. This involvement has been hypothesized following investigations
      based on histologic methods, radiologic imaging, photoelastic models, bone scintigraphy, and
      finite element analysis. However, even though the above studies have been well designed, some
      issues may have affected their conclusions. In fact, histological findings are limited to
      experimental studies in animals. Moreover, accuracy of the results of the finite element
      model (FEM) depends on the detailed geometry, material properties, and boundary conditions of
      the FEM. Therefore, until now, there have been only speculations about whether RME can or
      cannot disarticulate these structures in humans. With advanced technology and the
      introduction of three-dimensional computed tomography imaging, that allow clinicians and
      researchers to quantitatively evaluate bone changes with minimal distortion and lower
      radiation dosage, Due to the high dose of x-ray of CT, high cost and the lack of study on the
      effect of the RME on circumaxillary sutures and spheno-occipital synchondrosis using imaging
      three-dimensional radiographic (CT). Because of the importance of the effect of the maxillary
      expansion on maxillary displacement, and the resulting significant clinical effects,
      especially at the level of improvement in the third class at the children. From here stems
      the need for this study on the effect of rapid maxillary expansion RME on the craniofacial
      sutures in children using cone beam computed tomography
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Growing patients between the age of 8 and 12 will be recruited from those who are visiting
        the Department of Orthodontics at University of Damascus Dental School.

        The study will evaluate the impact of maxillary expansion on craniofacial sutures using
        CBCT imaging.
      
Keywords: Corrective Orthodontics; CBCT; Rapid Maxillary Expansion; Cone Beam Computed Tomography; Hyrax Expansion; Craniofacial Sutures