Evaluation of two dental registration-splint techniques for surgical navigation in cranio-maxillofacial surgery

Abstract

BACKGROUND: Surgical navigation requires precise registration of the pre-operative image dataset to the patient in the operation theatre. Different marker-based and marker-free registration techniques are available, each of them with advantages and disadvantages regarding precision and clinical handling. In this model study, the precision of two dental splint techniques for marker-based registration is analyzed. MATERIALS AND METHODS: A synthetic full-size human skull was registered with its cone beam computed tomography dataset using (a) a dentally-mounted "rapid" occlusal splint with five titanium screws directly attached to the splint, (b) an "extender", a dentally-mounted occlusal splint with similar fiducials fixed to an extension of the splint. The target registration error was measured for 170 landmarks distributed over the viscero-and neurocranium in 10 repeats per splint type using the Vector Vision(2) (BrainLAB AG, Heimstetten, Germany) navigation system. Statistical and graphical evaluations were performed per anatomical region. RESULTS: In the periorbital region, the rapid splint, with an average deviation of 1.50 mm (SD = 0.439) showed greater accuracy than the extender with 1.76 mm (SD = 0.525). The viscerocranial results for both splints were similar (extender 1.84 mm, SD = 0.559, rapid occlusal splint 1.86 mm, SD = 0.686). In the cranial vault region, registration with the extender (2.33 mm, SD = 0.685) proved to be more precise than with the rapid splint (2.86 mm, SD = 0.929). CONCLUSIONS: Due to the more compact dimension of the rapid occlusal splint, errors close to the splint were smaller compared to the extender technique. The advantage of greater distances between the registration fiducials on the extender is particularly important in areas such as the orbital roof, the cranial vault, and the lateral skull base.

Precision of a Novel Craniofacial Surgical Navigation System Based on Augmented Reality Using an Occlusal Splint as a Registration Strategy

“…According to the study of Venosta et al . 26 , a splint of a considerable size could be an obstacle during periorbital and maxillofacial surgery and influence the effect of the navigation. We thus used a narrow-edged occlusal splint (from lateral to lateral incisors) to fix the fiducial marker in our study to reduce its interference with the intraoral operation.…”

Target Registration Errors in Navigation-assisted Mandibular Surgery According to the Tracking Methods and the Type of Markers

“…The head and neck areas have the characteristic of allowing the use of a bit splint, unlike registration in other surgical areas using mouth and teeth. 15 Noninvasive marker-based registration could be performed by attaching the markers on a template used in navigation surgery. An external RF that uses ducial markers in denture-xed acrylic template for mandibular navigation has been reported to demonstrate a registration accuracy that is similar to that of invasive markers placed on the bone but does not entail the invasive process of placing screws as markers.…”

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

“…With the widely employed laser registration, facial unevenness is scanned utilizing laser reflection and merged with CT data. However, problems have been encountered, such as errors generated by general anesthesia-induced skin shift, and difficulty in evaluation and correction of errors generated during surgery [20, 21, 22]. In the present study, CBCT images were acquired while the patient held a resin splint with 5 markers made of X-ray opaque resin in the mouth, and registration was performed considering these markers as basic coordinates.…”