Comparative Validity and Reproducibility Study of Various Landmark-Oriented Reference Planes in 3-Dimensional Computed Tomographic Analysis for Patients Receiving Orthognathic Surgery

Abstract

BackgroundThree-dimensional computed tomographic imaging has become popular in clinical evaluation, treatment planning, surgical simulation, and outcome assessment for maxillofacial intervention. The purposes of this study were to investigate whether there is any correlation among landmark-based horizontal reference planes and to validate the reproducibility and reliability of landmark identification.Materials and MethodsPreoperative and postoperative cone-beam computed tomographic images of patients who had undergone orthognathic surgery were collected. Landmark-oriented reference planes including the Frankfort horizontal plane (FHP) and the lateral semicircular canal plane (LSP) were established. Four FHPs were defined by selecting 3 points from the orbitale, porion, or midpoint of paired points. The LSP passed through both the lateral semicircular canal points and nasion. The distances between the maxillary or mandibular teeth and the reference planes were measured, and the differences between the 2 sides were calculated and compared. The precision in locating the landmarks was evaluated by performing repeated tests, and the intraobserver reproducibility and interobserver reliability were assessed.ResultsA total of 30 patients with facial deformity and malocclusion—10 patients with facial symmetry, 10 patients with facial asymmetry, and 10 patients with cleft lip and palate—were recruited. Comparing the differences among the 5 reference planes showed no statistically significant difference among all patient groups. Regarding intraobserver reproducibility, the mean differences in the 3 coordinates varied from 0 to 0.35 mm, with correlation coefficients between 0.96 and 1.0, showing high correlation between repeated tests. Regarding interobserver reliability, the mean differences among the 3 coordinates varied from 0 to 0.47 mm, with correlation coefficients between 0.88 and 1.0, exhibiting high correlation between the different examiners.ConclusionsThe 5 horizontal reference planes were reliable and comparable for 3D craniomaxillofacial analysis. These reference planes were useful in standardizing the orientation of 3D skull models.

Computer-Aided Planning in Orthognathic Surgery: A Comparative Study with the Establishment of Burstone Analysis-Derived 3D Norms

“…To set a normative database of 3D Burstone cephalometric measurements for Taiwanese Chinese, a total of 27 linear and nine angular measurements were generated using Simplant software. For this, all craniofacial bone and soft-tissue anatomical landmarks and reference planes (22,14, and 8 parameters, respectively) were standardized based on previous descriptions (Tables 1 and 2, Figures 2 and 3) [11,12,[33][34][35]. Two Burstone analysis-related anatomical landmarks (i.e., PtM and Ar) [11,12] were adapted; the anterior base length (S-N) replaced the cranial base length (Ar-PtM-N) and the Co-Go replaced Ar-Go for ramus length measurement.…”

Orientation of Cone-Beam Computed Tomography Image: Pursuit of Perfect Orientation Plane in Three Dimensions—A Retrospective Cross-Sectional Study

“…They used the FH plane and lateral semicircular canal plane (LSP) in their study and demonstrated satisfactory results with different FH planes and LSP plane for the orientation of 3D skull models. 20 Daboul et al used left and right Porion (Po) and left Orbitale (Or) on the multiplanar reconstruction view for defining the FH plane and showed excellent intra-and interexaminer reproducibility of FH planes in magnetic resonance imaging. 30 A plane can be constructed using two or many landmarks.…”

“…On the other hand, reorienting the CBCT images using stable cranial landmarks and reference structures may be a practical alternative. 20 In literature, different orientation methods have been reported for the orientation of CBCT images. Most of these methods utilize the modification of common 2D planes such as Frankfort horizontal (FH) plane and focused on orienting the head in sagittal plane (pitch) only.…”

“…Most of these methods utilize the modification of common 2D planes such as Frankfort horizontal (FH) plane and focused on orienting the head in sagittal plane (pitch) only. 20,21 The evaluation of the relationship between landmark-based reference planes and NHP on 2D cephalograms showed that FH plane, Krogman-Walker Line, and Palatal plane are the close approximation of NHP. 4,22,23 However, the reliability and reproducibility of these anatomical reference planes for 3D CBCT orientation has not been evaluated.…”

A study of the parameters that influence orthosurgical treatments

“…A study of the parameters that influence orthosurgical treatments it can be limited with regard to major skeletal shifts 7,15 . Proper orthosurgical management with good multidisciplinary coordination will improve function with better stability of results.…”