Accuracy of Upper Jaw Positioning With Intermediate Splint Fabrication After Virtual Planning in Bimaxillary Orthognathic Surgery

Abstract

The purpose of the study is to present and discuss a workflow regarding computer-assisted surgical planning for bimaxillary surgery and intermediate splint fabrication. This study describes a protocol starting from wax bite registration to fabrication of the necessary intermediate splint. The procedure is a proof of concept to replace not only the model surgery but also facebow registration and transfer from facebow to articulator. Three different modalities were utilized to obtain this goal: cone beam computed tomography (CBCT), optical dental scanning, and 3-dimensional printing. A universal registration block was designed to register the optical scan of the wax bite to the CBCT data set. Integration of the wax bite avoided problems related to artifacts caused by dental fillings in the occlusal plane of the CBCT scan. Fifteen patients underwent bimaxillary orthognathic surgery. The printed intermediate splint was used during the operation for each patient. A postoperative CBCT scan was taken and registered to the preoperative CBCT scan. The difference between the planned and the actual bony surgical movement at the edge of the upper central incisor was 0.50 ± 0.22 mm in sagittal, 0.57 ± 0.35 mm in vertical, and 0.38 ± 0.35 mm in horizontal direction (midlines). There was no significant difference between the planned and the actual surgical movement in 3 dimensions: sagittal (P = 0.10), vertical (P = 0.69), and horizontal (P = 0.83). In conclusion, under clinical circumstances, the accuracy of the designed intermediate splint satisfied the requirements for bimaxillary surgery.

A New 3D Tool for Assessing the Accuracy of Bimaxillary Surgery: The OrthoGnathicAnalyser

“…One of the key issues in obtaining a favorable postoperative outcome is an accurate transfer of the 3D planned bony movements to the patient in the operating theatre. Despite the emergence of intra-operative navigation tools, the interocclusal wafer remains the most commonly used device to transfer the 3D orthognathic planning to the patient in the operating theatre [ 4 , 5 ]. The interocclusal wafer contains information concerning the positioning of maxillary and mandibular segments and guides the sagittal and transverse displacements of the maxilla and mandible during surgery.…”

An integrated orthognathic surgery system for virtual planning and image-guided transfer without intermediate splint

“…Recently, virtual simulation of the model surgery was carried out and an intermediate splint was fabricated based on the virtual model surgery results (Choi et al, 2012(Choi et al, , 2009Kim et al, 2011;Song and Baek, 2009;Sun et al, 2013). There was no significant difference between planned and actual surgical movements with an intermediate splint fabricated after virtual planning (Sun et al, 2013). However, there were significant differences between the virtual model surgery result and the expected maxilla position (theoretically calculated position result) according to the surgical plan ).…”

“…However, there was no significant difference between planned and executed movements of the maxilla using surgical splints combined with an external reference point (Bouchard and Landry, 2013). Recently, virtual simulation of the model surgery was carried out and an intermediate splint was fabricated based on the virtual model surgery results (Choi et al, 2012(Choi et al, , 2009Kim et al, 2011;Song and Baek, 2009;Sun et al, 2013). There was no significant difference between planned and actual surgical movements with an intermediate splint fabricated after virtual planning (Sun et al, 2013).…”

A precisão da cirurgia ortognática com placas de titânio personalizadas: revisão sistemática

“…Other studies have evaluated surgical precision three-dimensionally (Mazzoni et al, 2010;Hernández-Alfaro and Guijarro-Martínez, 2013;Sun et al, 2013;Stokbro and Thygesen, 2018a). The stability of the titanium plates was acceptable both immediately and long term.…”

“…Recently, 3D virtual surgical planning has gained ground due to better control and responses of bone movements (Hernández-Alfaro and Guijarro-Martínez, 2013; Lin and Lo, 2015;Brunso et al, 2016Brunso et al, , 2017. Interocclusal splint printing through computer-aided design (CAD) and computer-aided manufacturing (CAM) for bone repositioning is already widely used and has shown good results (Xia et al, 2007;Hernández-Alfaro and Guijarro-Martínez, 2013;Sun et al, 2013;Kwon et al, 2014).…”