Three-dimensional Analysis and Evaluation in Orthognathic Surgical Cases with Facial Asymmetry

Abstract

Two-dimensional cephalometric analysis is commonly used in planning and evaluating the outcome of orthognathic surgery. It is difficult to arrive at an accurate evaluation with this method, however, as the jaw bones overlap in profile. Therefore, the purpose of this study was to use 3-dimensional (3-D) orthognathic treatment planning software for measurement of distances and angles to evaluate change in dentofacial morphology and stability after orthognathic surgery in patients with jaw deformity and facial asymmetry. Computed tomography with SimPlant O&O (Materialize Dental, Belgium) was used to obtain data at before surgery (T1) and at 1 month (T2) and 1-2 years postoperatively (T3). Reference points, reference planes, and evaluation items were set to measure angles and distances. The average values at T1, T2, and T3 and the standard deviations were obtained. The analyses of change in distance and angle between T1 and T2 in both the maxilla and mandible revealed that the amount of postoperative deviation and change was greatest in the mandible (p<0.05). These findings showed a correlation between postoperative change in position of the chin and symmetry. Only a minimal amount of change was observed between T2 and T3 in both the maxilla and mandible. The results also revealed a correlation between positional change in both the proximal and distal bone segments and stability. It was found to be possible to determine change in horizontal, vertical, and anterior/posterior angle in both the maxilla and mandible by such 3-D analysis. The results suggest that the chin is the most appropriate facial element for evaluation of symmetry after orthognathic surgery.

[Retracted] 3D Kinematic Analysis of Intelligent Vision Sensor Image in Football Training

“…The core modules of the system can be divided into acquisition modules, processing modules, and communication modules. Expansion modules include storage expansion modules, unit modules, display modules (with touch screen), and power modules [16]. The whole system can start acquisition and detection commands through communication interface, internal cycle trigger, touch screen, and external trigger of unit interface, complete image acquisition through acquisition module and complete image processing in DSP, and then transmit it to PC or other through communication interface [17].…”

The Effect of Orthognathic Surgery on Soft-Tissue Facial Asymmetry: A Longitudinal Three-Dimensional Analysis

“…In recent years, the evaluation of facial morphology increasingly evolved, moving from direct anthropometry to indirect assessments, through two-and three-dimensional (3D) radiographic and optical imaging systems 2,3,[9][10][11] . These instruments permit not only a facial analysis based on landmarks, but also a more complete assessment of the whole surface 12 .…”

Mandibular Stability After Sagittal Split Ramus Osteotomy With Hybrid Technique in Asymmetric Patients

“…3 and 4); the frontmost point of the sutura nasofrontalis (nasion, Na); the lowest point of the orbital bones (orbitale, OrRt, OrLt); the top points of the external auditory canal superior margins (porion, PoRt, PoLt); the anterior nasal spine (ANS); the lowest facing point of the front margin of the foramen magnum (basion, Ba); the deepest part of the upper/ lower, left/right first molar tooth cervix alveolar crests (U6Rt, U6Lt, L6Rt, L6Lt); the uppermost point of left/right mandibular condyle heads (condylion, CoRt, CoLt); and the lowest external point of the chin (menton, Me). The definition of the anatomical landmarks was established with reference to the work by Kogou et al 5 The right and left sides were analyzed after identifying the ''D side'' and ''Nd side'' according to the direction in which the patient's chin was deviated.…”

“…The three-dimensional (3D) reconstructed images based on CT data enable high-precision 3D assessment of the maxillofacial frame, which is especially important in the evaluation of patients with facial asymmetry. 5 In this study, we used 3D reconstructed CT images to analyze the postoperative stability of patients with mandibular asymmetry who underwent hybrid fixation after BSSRO.…”