The University Münster model surgery system for orthognathic surgery - The digital update

Abstract

Aim The aim of this work is to present a digital methodology of a conventional articulator based planning protocol. Methods The digital counterpart consists of intra-oral scans (3Shape) and a free available 3D mesh software (Meshmixer, Autodesk). The maxillary position in relation to the reference plane used and the arbitrary hinge axis were determined mathematically from landmarks on cephalometric x-rays and frontal photographs. Distances and angles were calculated to virtually mount the digital jaws in Meshmixer’s wold frame. Virtual planning is done by cloning and moving the jaws according to the preliminary surgery plan. The spatial movements of the jaws are measured by attached reference points. Results This digital approach eliminate the need for articulator hardware and laboratory plaster work. It enables all planning scenarios as they are also possible with conventional plaster-based procedures. The method is time-saving, practical and cost-effective. Standard dimensions of articulators and face-bows have been incorporated in the implementation. This reduction of individual patient values puts the accuracy of the presented method within the range of conventional model surgery. Conclusion Arbitrary planning will continue to have its place in orthognathic surgery, especially when digital methods can improve the overall process. The method presented can be seen as a cost-effective alternative for patients who do not require technically complex planning.

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

“…It was shown that using the DMMS [ 16 ], the three-dimensional error of the overall process, from preoperative data collection through surgery, to the six-week follow-up, is 0.8 mm ± 0.5 mm and, therefore, below the threshold considered clinically acceptable of two millimeters in translation. The values for pitch (0.9° ± 0.7°), yaw (0.9° ±0.8°), and roll (0.5° ± 0.5°) are also below the clinically accepted four degrees.…”

“…The study took place at the University Hospital Münster, Germany. All patients included in this study were virtually planned with the Digital Münster Model Surgery (DMMS) system [ 16 ]. After an interdisciplinary consensus on orthodontic preparation, virtual planning, surgical plan, and intended postoperative occlusion, all patients underwent surgery at the Department of Cranio-Maxillofacial Surgery.…”

“…Upper and lower jaws were scanned with TRIOS ® Ortho (3Shape, Copenhagen, Denmark), and bite scans were taken after a reproducible mandibular position had been achieved using the Dawson method [ 18 ]. The planning sequence is clearly described in a former publication [ 16 ]. Surgery was performed with the aid of 3D printed (Solflex 350, W2P Engineering, Vienna, Austria) intermediate and final splints (Ortho Clear, NextDent B.V. Soesterberg, the Netherlands).…”

“…A new three-dimensional orthognathic surgical planning system based on intraoral scans using arbitrary articulator dimensions has been introduced [ 16 ]. It is mandatory to validate any new system to justify the intended benefit for the patient.…”

Surgical Classification for Preclinical Rat Femoral Bone Defect Model: Standardization Based on Systematic Review, Anatomical Analysis and Virtual Surgery

“…One feasible approach is the application of software tools to conduct virtual surgery by simulating operative procedures on skeletal models reconstructed from radiological data [ 19 , 20 ]. This allows precise simulation of operative treatment in a time-saving and cost-effective manner, supporting direct visualization of the surgical results, such as bone tunnel drilling and osteotomy [ 21 ]. In clinical practice, virtual surgeries have been adopted for preoperative planning of orthognathic and limb operations.…”