2D-to-3DMaxiDeform: A computer-aided approach for 3D construction of maxillary sinus from PA and lateral X-ray images

3D volume construction of the maxillary sinus is important for understanding the 3D surface morphology of the maxillary sinuses and detecting changes or obstruction in sinuses. It is important to detect the pathological conditions affecting the sinuses and to determine the treatment outcomes. The cases of sinusitis and various other pathoses in maxillary sinuses are getting comparatively higher than in other sinuses. Therefore, analysis of maxillary sinus structure has some clinical importance. 3D volume construction from Computed Tomography (CT) can help in the volumetric study of the maxillary sinus. Nonetheless, CT imaging is expensive and has a higher radiation dose than X-ray imaging. Thus, the 3D construction from X-ray images is a challenging problem. This paper proposed a 3D construction method for maxillary sinus from lateral and Posterior-anterior (PA) 2D X-ray images. A novel 3D maxillary sinus construction model (2D-to-3D-MaxiDeform) is proposed which evolves the shape and size of the maxillary sinus providing the required volume, and other linear measurements in mesh format. The 2D-to-3DMaxiDeform uses a 3D point cloud template of the maxillary sinus and applies for registration on the template model. The deformation moves the 3D template points to the required positions of the X-ray image contours. The registration of the template model before deformation into the required shape makes sure the size, position, and angle of the template model are mapped with the input X-ray contours. The evaluation of the 2D-to-3DMaxiDeform achieves an average accuracy of 0.83, mDSC (mean Dice similarity coefficient) of 0.80, mIoU (mean Intersection over Union) of 0.67, recall of 0.90, precision of 0.74, specificity of 0.78 and RMSE of 2.3 mm. The proposed method is the first and novel approach for maxillary sinus 3D construction from X-ray images. The result shows that the proposed method could be a valuable tool for generating 3D models of the maxillary sinus to be used in a clinical setting.