[Innovative methods and developments in oral care. 3D planning in oral and maxillofacial surgery]. / Serie: Innovatieve technieken en ontwikkelingen in de mondzorg. 3D-planning in de mka-chirurgie.

With the use of cone beam computed tomography, intraoral scanning and 3D stereophotogrammetry, a virtual 3D head model of a patient can be reconstructed with image fusion. In this way, the malposition, deficiency and other anomalies at the level of bone, dentition and soft tissue can be quantified objectively. The desired position of the dentition, occlusion and soft tissue in the facial profile can be virtually drawn in and used as a guideline for treatment planning. Based on the principle of backward planning, it is possible to determine what repositioning of the jaw is required, where there is a need for bone augmentation and how many dental implants are necessary to obtain the desired treatment outcome. From this perspective, 3D treatment planning has become a treatment standard for the 4 clinical pillars supporting oral and maxillofacial surgery, specifically orthognathic surgery, implantology, craniofacial surgery and head & neck oncology. 3D planning has influenced today's workflow, planning of complex surgery and contributed to useful further innovations and efficient healthcare.

[The 3D-printed surgical guides used during genioplasty]. / De 3D-geprinte zaag- en repositiemal voor een kinplastiek.

Genioplasty is a seemingly simple procedure performed to correct the bony chin. The results of the procedure are, however, strongly correlated with the experience of the surgeon. 3D-printed surgical guides could act as a transfer modality to translate the preoperative planning directly into the achieved result. Prospective studies evaluating the usefulness of the 3D-printed surgical guides have not yet been carried out and consensus regarding the best design is lacking. In order to become more familiar with working with surgical guides, a genioplasty using 3D-printed surgical guides was performed. The postoperative analysis of the achieved result showed minor differences compared to preoperative planning. Surgical guides have the potential to improve the accuracy and predictability of genioplasty. The design should be further refined and the added value of the guides should be confirmed by means of prospective research.

[Reconstruction after facial trauma with dento-alveolar injury]. / Reconstructie na aangezichtstrauma met dentoalveolair letsel.

While abroad, a healthy 36-year-old woman slammed head-on into a rock wall at high speed, resulting in significant facial trauma. The initial trauma care and first aid took place abroad. In the Netherlands, the woman was referred to the Department of Oral and Maxillofacial Surgery (OMFS) for reconstruction of her face and alveolar processes, gingiva and dentition. In view of the seriousness of the injuries, a 3D treatment plan was drawn up in a multidisciplinary collaboration with an OMF surgeon, an implantologist, dentist and dental technician. By making a digital setup of both the top and bottom front in advance, it was possible to work predictably. The first step consisted of bone augmentation by means of an iliac crest graft to reconstruct the major bone defects of the superior and inferior alveolar processes. Implants were then placed in the upper and lower jaws in the ideal position for the suprastructure by means of drill jigs. Within 10 months after the trauma, the implant bridges could be placed on individual zirconia frameworks to optimally restore oral function and aesthetics, completing the reconstruction.

Surgical accuracy in 3D planned bimaxillary osteotomies: intraoral scans and plaster casts as digital dentition models.

The aim of this study was to assess whether the use of intraoral scans (IOS) is an eligible alternative to conventional plaster casts in terms of surgical accuracy of three-dimensionally planned bimaxillary osteotomies. This retrospective cohort study included patients who underwent bimaxillary surgery between 2016 and 2020 in the Department of Oral and Maxillofacial Surgery at Radboud University Medical Center, Nijmegen. Three-dimensional virtual planning was performed with the use of plaster casts in one group and IOS in the other group. Cone beam computed tomography scans were acquired preoperatively and at 1 week following surgery. By using voxel-based matching, the maxillary movements were quantified in six degrees of freedom. The primary outcome variable, surgical accuracy, was defined as the difference between the planned maxillary movements and those achieved. Of 152 patients, 113 were documented with plaster casts and 39 with IOS. The surgical accuracy was comparable in terms of maxillary vertical, sagittal, and transverse translations, as well as roll and yaw. Maxillary pitch (difference 0.55 ± 0.26°; P = 0.001) was in favour of the IOS group. This study demonstrated that IOS can be used as an alternative to conventional plaster casts in the three-dimensional planning of bimaxillary osteotomies.

Three-dimensional virtual simulation of alar width changes following bimaxillary osteotomies.

The aim of this study was to evaluate the accuracy of three-dimensional (3D) soft tissue simulation of nose width changes following bimaxillary osteotomies and to identify patient- and surgery-related factors that may affect the accuracy of simulation. Sixty patients (mean age 26 years) who underwent bimaxillary osteotomies participated in this study. Cone beam computed tomography scans were acquired preoperatively and at 1-year postoperative. The 3D hard and soft tissue rendered preoperative and postoperative virtual head models were superimposed, after which the maxilla and mandible were segmented and aligned to the postoperative position. The postoperative changes in alar width were simulated using a mass tensor model (MTM)-based algorithm and compared with the postoperative outcome. 3D cephalometric analyses were used to quantify the simulation error. The postoperative alar width was increased by 1.6±1.1mm and the mean error between the 3D simulation and the actual postoperative alar width was 1.0±0.9mm. The predictability was not correlated to factors such as age, sex, alar cinch suture, VY closure, maxillary advancement, or a history of surgically assisted rapid maxillary expansion. The MTM-based simulation model of postoperative alar width change was found to be reasonably accurate, although there is room for further improvement.

Photograph-based ergonomic evaluations using the Rapid Office Strain Assessment (ROSA).

The Rapid Office Strain Assessment (ROSA) was developed to assess musculoskeletal disorder (MSD) risk factors for computer workstations. This study examined the validity and reliability of remotely conducted, photo-based assessments using ROSA. Twenty-three office workstations were assessed on-site by an ergonomist, and 5 photos were obtained. Photo-based assessments were conducted by three ergonomists. The sensitivity and specificity of the photo-based assessors' ability to correctly classify workstations was 79% and 55%, respectively. The moderate specificity associated with false positive errors committed by the assessors could lead to unnecessary costs to the employer. Error between on-site and photo-based final scores was a considerable ∼2 points on the 10-point ROSA scale (RMSE = 2.3), with a moderate relationship (ρ = 0.33). Interrater reliability ranged from fairly good to excellent (ICC = 0.667-0.856) and was comparable to previous results. Sources of error include the parallax effect, poor estimations of small joint (e.g. hand/wrist) angles, and boundary errors in postural binning. While this method demonstrated potential validity, further improvements should be made with respect to photo-collection and other protocols for remotely-based ROSA assessments.

Optimal treatment of partial thickness burns in children: a systematic review.

A large part of the patient population of a burn centre consists of children, most of whom are younger than four years. The majority of these young children suffer from superficial and deep partial thickness scald burns that may easily deepen to full thickness burns. A proper wound therapy, that prevents infection and ensures a moist wound condition, might prevent the deterioration of the wound. Therefore, we performed a systematic review of wound management and dressing materials to select the best treatment option for children with burns. A search in Medline and Embase revealed 51 articles for a critical appraisal. The articles were divided into randomized controlled trials, cohort studies and a group of case-reports. Total appraisal did not differ much amongst the groups; the level of evidence was highest in the randomized controlled trials and lowest in the case-reports. In 16 out of 34 comparative studies, silver sulfadiazine or a silver sulfadiazine/chlorhexidine-gluconate combination was the standard of wound care treatment. The competitor dressing was Biobrane(®) in six studies and amnion membrane in three. Tulle gauze, or tulle gauze impregnated with an antibacterial addition were the standard of care treatment in seven studies. In general, membranous dressings like Biobrane(®) and amnion membrane performed better than the standard of care on epithelialization rate, length of hospital stay and pain for treatment of partial thickness burns in children. However, hardly any of the studies investigated long-term results like scar formation.