Linear measurements of sinus floor elevation based on voxel‐based superimposition of cone beam computed tomography images

Abstract

Background Postsurgical evaluation of sinus floor elevation regularly involves linear measurements of the elevated volumes in the cone beam computed tomography (CBCT) images. The accuracy of measurements could be compromised due to ill‐defined sinus floor outline if implants are placed simultaneously. Purpose The aim was to examine a CBCT superimposition method to improve the measurement accuracy. Materials and Methods Twenty patients who received transalveolar sinus floor elevation with immediate implantation were enrolled. CBCTs before and after surgery were transformed into digital imaging and communications in medicine format and imported into the Dolphin Imaging software. Voxel‐based superimposition was automated to merge the files. In the superimposed image, parameters including alveolar bone height, protruded implant length, and total elevated height were measured. The superimposition and measurements were performed independently by two examiners and in two timepoints with 1‐week time interval. We used intraclass correlation coefficient (ICC) to analyze the interexaminer and intraexaminer agreements. Results Of measured parameters, the mean of difference between two timepoints ranged from 0.18 to 0.26 mm by examiner 1, and from 0.16 to 0.20 mm by examiner 2. ICCs were equal or greater than 0.98, indicating perfect intraexaminer agreement. For interexaminer reliability, the largest mean of difference was 0.27 mm in measuring alveolar bone height between two examiners. ICCs were greater than 0.98, showing perfect interexaminer agreement. Conclusions The voxel‐based superimposition of pre‐ and post‐surgical CBCT images with Dolphin Imaging is an effective and reliable way for linear measurements so as to assess the surgical outcome. There is minimal effect on reproducibility of measured data by different timepoints or performers.

Radiographic assessment of deproteinized bovine bone mineral (DBBM) and collagen‐stabilized DBBM for transalveolar sinus floor elevation: A 2‐year retrospective cohort study

“…Three anatomical landmarks from the maxilla were chosen to match the two images, including the mesial incisal angle of the right upper central incisor, mesial buccal cusp of the upper first molar on the nonsurgical side or one cusp of the adjacent tooth to the implant, and the meeting point of anterior nasal spine and piriform aperture (Figure 3). The voxel‐based imposition was automated by the software to match the density information of the two images 25 . After merging, the superimposed image was then oriented with the long axis of the implant.…”

“…A commercially available 3‐dimensional image software, Dolphin Imaging version 11.95 (Dolphin Imaging & Management Solutions) was employed for image processing. Multiplanar (axial, coronal, and sagittal) and 3‐dimensional reconstructed images were generated after importing each DICOM file 25 …”

“…Multiplanar (axial, coronal, and sagittal) and 3-dimensional reconstructed images were generated after importing each DICOM file. 25 The usage of Dolphin in this study was described as follows: First, the preoperative CBCT image was superimposed with the postoperative image using voxel-based superimposition. The slice thickness of the CBCT in Dolphin software was 0.5 mm.…”

“…The voxel-based imposition was automated by the software to match the density information of the two images. 25 After merging, the superimposed image was then oriented with the long axis of the implant. In the coronal plane, the initial sinus floor, alveolar ridge, implant, bone substitutes, and the elevated Schneiderian membrane could all be visually identified.…”

Automatic Segmentation Method for Cone-Beam Computed Tomography Image of the Bone Graft Region within Maxillary Sinus Based on the Atrous Spatial Pyramid Convolution Network

“…In oral implantation, dental implants may penetrate the wall of the maxillary sinus when the maxillary posterior teeth are missing, which can cause serious problems [1] . Sinus floor elevation to ensure sufficient bone mass has been widely applied to resolve this issue, and involves the implantation of bone material into the bottom of the maxillary sinus which will grow into the bone graft (BG) after a period of time [2] . Measurement and analysis of the BG region of postoperative patients, based on cone-beam computed tomography (CBCT) images, are required to monitor the growth of BG and evaluate BG materials [3] .…”