CAD/CAM splint and surgical navigation allows accurate maxillary segment positioning in Le Fort I osteotomy

Abstract

Purpose To evaluate the accuracy of the maxillary segment positioning method using a splint fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) and surgical navigation in patients who required two-jaw surgery. Methods Subjects were 35 patients requiring two-jaw surgery. A 3-dimensional (3D) skull model was prepared using cone-beam computed tomography (CBCT) data and dentition model scan data. Two-jaw surgery was simulated using this model, and a splint for maxillary positioning was fabricated by CAD/CAM. Using coordinate transformation software, the coordinate axis of surgical simulation data was merged with the navigation system, and data were imported to the navigation system. The maxillary segment was placed using the CAD/CAM splint, and consistency of the maxillary segment position with that planned by simulation was confirmed using the navigation system. CBCT taken at 4 weeks postoperatively and the prediction image fabricated using surgical simulation were superimposed. Predicted movement distances (PMD) at 6 arbitrary measurement points and actual movement distance (AMD) in surgery were measured. Differences of 3D measurements between the surgical simulation and postoperative results were evaluated. Results No significant differences were seen between PMD and AMD at most measurement points on the X and Y axes. Although significant differences between PMD and AMD were seen on the Z axis, no difference was evident between linear distance on the estimated image and postoperative CBCT image at most measurement points in 3D space. Mean error at measurement points between the PMD and AMD ranged from 0.57 mm to 0.78 mm on the X axis, 0.64 mm–1.03 mm on the Y axis, and 0.84 mm–0.90 mm in the Z axis. Conclusion Position of the maxillary segment moved by the CAD/CAM splint in Le Fort I osteotomy was almost consistent with the position established by simulation using the navigation system, confirming clinical accuracy.

In Vivo Accuracy of a New Digital Planning System in Terms of Jaw Relation, Extent of Surgical Movements and the Hierarchy of Stability in Orthognathic Surgery

“…In contrast to landmark-based registrations, the semi-automated approach used here using best-fit alignment followed by the iterated closest-point algorithm over pVision3D [ 20 ] can be considered a strength of the study. Although the placement of landmarks has been confirmed to have high reproducibility, the error caused by the identification of the landmarks ranged from 0.02 to 2.47 mm [ 30 , 35 ].…”

“…The STL files in postoperative occlusion were imported as “actual data elements”. Because there is a greater likelihood that post-operative differences were caused by surgical positioning of the mandible rather than the maxilla [ 19 , 20 , 21 ], the maxillary record served as the reference for registration. Planned and postoperative jaws were matched through best-fit alignment of the maxillae, which allows the identification of possible deviations between planned and postoperative mandibular positions.…”

Ciências da Saúde: desafios, perspectivas e possibilidades - Volume 1

“…Já após um mês, houve precisão dimensional acima de 90%, ao se utilizar planejamento cirúrgico virtual em 66,6% dos casos estudados (KOYACHI et al, 2020). A precisão dimensional dos guias cirúrgicos obtidos por CAD/CAM e prototipagem rápida apresentou erro dimensional absoluto dentro dos padrões clinicamente 34 aceitos, com valores bastante acurados e precisos (SHAHEEN et al, 2017;SHIROTA et al, 2019XU et al, 2020), não havendo diferenças estatisticamente significativas entre os métodos convencional e virtual, após período entre um e dois anos (XU et al, 2020). Ao se comparar medidas lineares em uma mandíbula (modelo ex vivo) e em seu respectivo biomodelo, obtidos pela tecnologia CAD/CAM, utilizando softwares gratuitos, também não foram verificadas diferenças estatisticamente significativas (RENDÓN-MEDINA et al, 2018).…”

“…Dessa forma, os autores concluíram que o planejamento virtual de cirurgias ortognáticas demandou menor tempo que o método convencional, sobretudo em procedimentos mais complexos. Shirota et al (2019) investigou a acurácia dos guias cirúrgicos feitos por meio da prototipagem e impressão 3D, em cirurgias ortognáticas realizadas sob a verificação de um sistema de navegação com rastreamento óptico para um posicionamento preciso. Os 35 pacientes envolvidos nesse ensaio clínico foram submetidos às osteotomias Le Fort I e sagital bilateral.…”

Prototipagem Rápida Em Cirurgias Ortognáticas: Uma Revisão Integrativa

“…KOYACHI et al, 2020). A precisão dimensional dos guias cirúrgicos obtidos por CAD/CAM e prototipagem rápida apresentou erro dimensional absoluto dentro dos padrões clinicamente aceitos, com valores bastante acurados e precisos(SHAHEEN et al, 2017;SHIROTA et al, 2019XU et al, 2020), não havendo diferenças estatisticamente significativas entre os métodos convencional e virtual, após período entre um e dois anos (XU et al, 2020). Ao se comparar medidas lineares em uma mandíbula (modelo ex vivo) e em seu respectivo biomodelo, obtidos pela tecnologia CAD/CAM, utilizando softwares gratuitos, também não foram verificadas diferenças estatisticamente significativas (RENDÓN-MEDINA et al, 2018).…”