Soft-Tissue Simulation for Computational Planning of Orthognathic Surgery

Abstract

Simulation technologies offer interesting opportunities for computer planning of orthognathic surgery. However, the methods used to date require tedious set up of simulation meshes based on patient imaging data, and they rely on complex simulation models that require long computations. In this work, we propose a modeling and simulation methodology that addresses model set up and runtime simulation in a holistic manner. We pay special attention to modeling the coupling of rigid-bone and soft-tissue components of the facial model, such that the resulting model is computationally simple yet accurate. The proposed simulation methodology has been evaluated on a cohort of 10 patients of orthognathic surgery, comparing quantitatively simulation results to post-operative scans. The results suggest that the proposed simulation methods admit the use of coarse simulation meshes, with planning computation times of less than 10 seconds in most cases, and with clinically viable accuracy.

Soft-tissue simulation of the breast for intraoperative navigation and fusion of preoperative planning

“…Our approach to model the breast is to identify soft and rigid anatomical elements in the region of interest, as shown in Figure 2 , define efficient coupling boundary conditions between them, and solve the tissue deformation using FE analysis. This approach mimics previous work for the simulation of orthognathic surgery Alcañiz et al (2021) , but applied to breast simulation. We follow this approach to simulate both the interaction between the soft-tissue and stiff or bone tissue, as well as to handle contact between the breast soft-tissue and the IORT applicator.…”

“…We do this using Newton’s method, with a conjugate gradient solver for the solution of linear systems of equations. We refer the reader to Alcañiz et al (2021) for details.…”

“…Computational preoperative planning of surgical interventions entails multiple benefits, in particular reduced risk to the patient and shorter interds, computational preoperative planning has seen success in applications such as radiotherapy Calvo et al (2014) , neurosurgery Prada et al (2014) ; Kahl et al (2021) ; Nemoto et al (2002) , or orthognathic surgery Alcañiz et al (2021) .…”

Differentiable Simulation for Outcome‐Driven Orthognathic Surgery Planning

“…Physics‐based mass‐spring [KGC*96] and hyperelasitc [CLP03] models of soft tissue were amongst the first simulation approaches to be developed and tested. Hyperelastic modelling continues to be used for recent works [APG*21, KKR*19, VWWSGB21]. Recent works often investigate previously unmodelled physical phenomena, such as time‐dependent bone healing [VWWSGB21], lip and mucosa sliding [KKR*19], bone‐cutting forces [YDX*14], or constrained motion models of the TMJ [OVT*08].…”

Volumetric Change in the Masseter and Lateral Pterygoid after Mandibular Setback

“…Mandibular prognathism is a morphological abnormality occurring in the oral and maxillofacial regions, resulting in aesthetic and functional problems [ 1 , 2 , 3 , 4 ]. Although corrective and surgical methods are available for the treatment of mandibular prognathism, surgery is the most appropriate treatment for most adults [ 5 , 6 , 7 ]. However, young patients can be treated with orthodontic methods, which include timing treatment options, growth prediction of the mandible, and control of the growth patterns.…”