Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques.

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles.

RESULTS

After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used.

CONCLUSION

Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

OrthoCalc: The six degrees of freedom measurement workflow of rotational and displacement changes for maxilla positioning evaluation

BACKGROUND

This study is undertaken to establish the accuracy and reliability of OrthoCalc, a 3D application designed for the evaluation of maxillary positioning.

METHODS

We registered target virtual planned models, maxillary models from pre-operative and post-operative CT scans, and post-operative intra-oral scans to a common reference system, allowing for digital evaluation. To assess rotational changes, we introduced a novel measurement method based on virtual cuboid models. Displacement errors were calculated based on proposed registration matrices. We also compared OrthoCalc to established commercial medical software as a benchmark.

RESULTS

Statistical significance calculated showed no significant differences between OrthoCalc and commercial software. the biggest error of 0.04 degree in rotation change was found in the yaw. A maximum displacement change of 0.75 mm was found in the X direction.

CONCLUSIONS

Our study validates OrthoCalc as a precise and reliable tool for assessing maxillary position changes with six degrees of freedom in orthognathic surgery, endorsing its clinical utility.

Congenital Unilateral Zygomaticomaxillomandibular Fusion in a 4-year-old Girl

Congenital zygomaticomaxillomandibular (ZMM) fusion is an extremely rare and debilitating condition. Fusion of the jaws results in a severe limitation of the mouth opening accompanied by breathing and feeding difficulties. Mandibular fusions to the maxilla, palate, zygoma, and temporal bone are described in literature. We present the case of 4-year-old girl diagnosed with congenital unilateral ZMM fusion. She was treated surgically at 1 year and at 4 and a half years to release the fusion and to improve mouth opening. Second surgery was indicated due to recurrence. Management of young patients with congenital maxillomandibular fusion is challenging. The scarcity of cases makes formulating practice guidelines very difficult. If surgery is performed, the importance of postoperative physical therapy cannot be overstated. The goal of this article is to emphasize the risk of recurrence in ZMM fusion after surgical treatment and importance of regular follow-up.

Symmetry recovery in zygomaticomaxillary complex fractures compared to normal unfractured population: A new reliable 3D evaluation

OBJECTIVE

This study aims to quantify the facial symmetry of surgically treated zygomaticomaxillary complex (ZMC) fractures through a new reliable three-dimensional evaluation method, which is crucial for improving post-operative aesthetic and functional outcomes.

MATERIAL AND METHODS

Healthy patients and patients with surgically treated ZMC fractures were retrospectively reviewed. Using Brainlab Elements® the zygomatic bone and the orbit of each patient was segmented and mirrored. Subsequently, the mirrored side was matched with the other side via volume-based registration, using the segmented orbit as reference. Volumetric asymmetry was measured using 3-matic software, and a surface-based matching technique was used to calculate the mean absolute differences (MAD) between the surfaces of the two sides of the ZMC. The reliability of this novel method using volume-based registration was tested, and the intra-class correlation coefficient was assessed.

RESULTS

The MAD between the surfaces of the left and right sides in the control group was 0.51 mm (±0.09). As for the ZMC fracture group, MAD was 0.78 mm (±0.20) and 0.72 mm (±0.15) pre- and post-operatively, respectively. The MAD showed statistically significant differences between pre- and post-operative groups (p = 0.005) and between control and post-operative groups (p < 0.001). The intra-class correlation coefficient was high (≥0.99).

CONCLUSIONS

This evaluation method using mirroring and volume-based registration to determine the symmetrical position of the ZMC is reliable. The surface-based measurements revealed an improved symmetry after surgery. However, the symmetry of the treated patients remained lower than the control group.

Exploring long-term responses to immune checkpoint inhibitors in recurrent and metastatic head and neck squamous cell carcinoma

OBJECTIVES

Immune checkpoint inhibitors (ICI) have introduced a new era in the treatment of recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC). Optimal duration for ICI therapy is still unclear and the long-term outcomes and toxicity in patients responding to these therapies warrant further exploration. This study attempts to identify the clinical and biological determinants of a durable response and evaluate outcomes following ICI treatment discontinuation.

MATERIALS AND METHODS

A retrospective review of 181 patients treated with ICI for R/M HNSCC was conducted. Long-term responders were defined as patients who sustained disease control at least two years after initiating ICI therapy. We compared clinical and biological characteristics associated with these long-term responders against the broader treatment population.

RESULTS

10 % of R/M HNSCC patients treated with ICIs demonstrated a durable long-term response. Only three relapses (16 %) occurred after discontinuing ICI treatment in this subset, with a median follow-up of 52 months. Upon retreatment with ICI, two attained a documented response. Extended ICI response was observed even with < 2 years of treatment. 74 % of long-term responders experienced immune-related adverse events (irAEs), 37 % of which severe irAEs. Hypothyroidism was the most frequently reported irAEs. The predictive potential of systemic inflammation indices for clinical response appears to be limited.

CONCLUSIONS

ICI present an optimistic avenue for HNSCC patients, offering substantial long-term responses. The study suggests that a two-year treatment could be optimal and irAEs, although common, are typically mild.

Augmented and Virtual Reality for Preoperative Trauma Planning, Focusing on Orbital Reconstructions: A Systematic Review

BACKGROUND

This systematic review summarizes recent literature on the use of extended reality, including augmented reality (AR), mixed reality (MR), and virtual reality (VR), in preoperative planning for orbital fractures.

METHODS

A systematic search was conducted in PubMed, Embase, Web of Science and Cochrane on 6 April 2023. The included studies compared extended reality with conventional planning techniques, focusing on computer-aided surgical simulation based on Computed Tomography data, patient-specific implants (PSIs), fracture reconstruction of the orbital complex, and the use of extended reality. Outcomes analyzed were technical accuracy, planning time, operative time, complications, total cost, and educational benefits.

RESULTS

A total of 6381 articles were identified. Four articles discussed the educational use of VR, while one clinical prospective study examined AR for assisting orbital fracture management.

CONCLUSION

AR was demonstrated to ameliorate the accuracy and precision of the incision and enable the better identification of deep anatomical tissues in real time. Consequently, intraoperative imaging enhancement helps to guide the orientation of the orbital reconstruction plate and better visualize the precise positioning and fixation of the PSI of the fractured orbital walls. However, the technical accuracy of 2-3 mm should be considered. VR-based educational tools provided better visualization and understanding of craniofacial trauma compared to conventional 2- or 3-dimensional images.

A 16-year retrospective study of vascular anomalies in the head and neck region

Depending on the diagnostic modality, the classification of vascular anomalies varies and so does the nomenclature. The 'International Society for the Study of Vascular Anomalies' (ISSVA) is the most widely accepted classification in the literature and is mainly based on the radiologic and clinical presentation. The aim of this article is to review the clinical practice of diagnosis and treatment of vascular anomalies in the head and neck region in a university hospital, with special focus on the nomenclature. All patients with a vascular anomaly presenting to the department of oral and maxillofacial surgery were reviewed in a retrospective manner. Nomenclature, diagnostic process, lesion characteristics, treatment and outcome were examined. The lesions were (re)classified according to the ISSVA classification. A total of 185 patients were identified, of which 12.4% (n = 23) had a congenital anomaly. After reclassification, the most common lesions were venous malformations (n = 47, 25.4%), followed by lobular capillary hemangiomas (n = 17, 9.2%). A group of 39 anomalies could not be further specified. One hundred and one patients (54,6%) received treatment, of which 93 were treated surgically (92,1% of treated patients). Endovascular treatment was considered in 41 patients but applied in only eight. This strict selection led to a low a complication rate. We provide an overview of the clinical practice in the management of vascular anomalies in a university hospital. The histology report is a source of miscommunication because clinicians use the ISSVA classification, while pathologists use the WHO classification. Every professional involved should be aware of the differences in classification and nomenclature.

Indications and complications regarding titanium osteosynthesis in pediatric maxillofacial trauma: A scoping review and critical appraisal

With the advent of biodegradable osteosynthesis material, titanium osteosynthesis for ORIF in pediatric maxillofacial trauma is not as indisputable as before. The aim of this study was to conduct a scoping review to assess the indications, complications of ORIF with titanium osteosynthesis material in pediatric maxillofacial trauma. A systematic search was conducted in PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, gray literature (ICTRP and clinicaltrials.gov) for studies published until April 2022. 3436 studies were screened and finally 13 articles, compromising a sample of 340 pediatric patients were included after full text reading. Reported complications were infection (6.5% of population), malocclusion (5% of population) and dental maleruption (8% of population). Influence on future growth could not be assessed due to short and heterogeneous follow-up periods. Eight of the thirteen studies concluded to a positive and predictable outcome using titanium ORIF for displaced/complex pediatric maxillofacial fractures. Results of this review suggest that titanium ORIF for maxillofacial fractures in the pediatric population is a reliable treatment. The surgeon must be committed to following these patients longitudinally. Interpreting the results should, however, be done with great care, as most articles have a medium to high risk of bias and limited follow-up.

Value of six comorbidity scales for predicting survival of patients with primary surgery for oral squamous cell carcinoma

BACKGROUND

Comorbidities influence treatment outcome of oral squamous cell carcinoma (OSCC). This study compared the predictive performance of six comorbidity scales for overall survival after surgery for OSCC.

METHODS

We retrospectively analyzed OSCC patients, surgically treated at an academic center in Belgium between January 01, 2000 and January 01, 2020. Validity of the scales was evaluated using the area under the curve (AUC) of receiver operating characteristic curves.

RESULTS

Three hundred and twenty three patients were included. Elixhauser Comorbidity Index (AUC = 0.74, 95% CI: 0.55-0.92; AUC = 0.73, 95% CI: 0.55-0.80), modified Elixhauser Comorbidity Index (AUC = 0.72, 95% CI: 0.54-0.91; AUC = 0.69, 95% CI: 0.51-0.77), and Combined Comorbidity Index (AUC = 0.76, 95% CI: 0.58-0.84; AUC = 0.76, 95% CI: 0.59-0.84) were meaningful predictors for 2 and 5-year survival, respectively.

CONCLUSION

Selected comorbidity scales were capable of predicting overall survival for OSCC patients 2 and 5 years after primary surgery.

Tough Photo-Cross-Linked PCL-Hydroxyapatite Composites for Bone Tissue Engineering

Acrylate-based photo-cross-linked poly(ε-caprolactone) (PCL) tends to show low elongation and strength. Incorporation of osteo-inductive hydroxyapatite (HAp) further enhances this effect, which limits its applicability in bone tissue engineering. To overcome this, the thiol-ene click reaction is introduced for the first time in order to photo-cross-link PCL composites with 0, 10, 20, and 30 wt % HAp nanoparticles. It is demonstrated that the elongation at break and ultimate strength increase 10- and 2-fold, respectively, when the photopolymerization mechanism is shifted from a radical chain-growth (i.e., acrylate cross-linking) toward a radical step-growth polymerization (i.e., thiol-ene cross-linking). Additionally, it is illustrated that osteoblasts can attach to and proliferate on the surface of the photo-cross-linked PCL-HAp composites. Finally, the incorporation of HAp nanoparticles is shown to reduce the ALP activity of osteoblasts. Overall, thiol-ene cross-linked PCL-HAp composites can be considered as promising potential materials for bone tissue engineering.

Biomechanical evaluation of the human mandible after temporomandibular joint replacement under different biting conditions

Temporomandibular joint (TMJ) replacement with an implant is only used when all other conservative treatments fail. Despite the promising short-term results, the long-term implications of TMJ replacement in masticatory function are not fully understood. Previous human and animal studies have shown that perturbations to the normal masticatory function can lead to morphological and functional changes in the craniomaxillofacial system. A clearer understanding of the biomechanical implications of TMJ replacement in masticatory function may help identify design shortcomings that hinder their long-term success. In this study, patient-specific finite element models of the intact and implanted mandible were developed and simulated under four different biting tasks. In addition, the impact of re-attaching of the lateral pterygoid was also evaluated. The biomechanics of both models was compared regarding both mandibular displacements and principal strain patterns. The results show an excessive mediolateral and anteroposterior displacement of the TMJ implant compared to the intact joint in three biting tasks, namely incisor (INC), left moral (LML), and right molar (RML) biting. The main differences in principal strain distributions were found across the entire mandible, most notably from the symphysis to the ramus of the implanted side. Furthermore, the re-attachment of the lateral pterygoid seems to increase joint anteroposterior displacement in both INC, LML and RML biting while reducing it during LGF. Accordingly, any new TMJ implant design must consider stabilising both mediolateral and anteroposterior movement of the condyle during biting activities and promoting a more natural load transmission along the entire mandible.

Complications Following One-Stage Versus Two-Stage Surgical Treatment of Transverse Maxillary Hypoplasia

PURPOSE

Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy.

MATERIALS AND METHODS

This retrospective study included 74 consecutive patients (age range: 14 - 57 years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1 year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test.

RESULTS

No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P = .038).

CONCLUSIONS

Considering a similar complication rate and transversal stability, the choice between 1-stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

A novel fully automatic design approach of a 3D printed face specific mask: Proof of concept

The use of high quality facemasks is indispensable in the light of the current COVID pandemic. This study proposes a fully automatic technique to design a face specific mask. Through the use of stereophotogrammetry, computer-assisted design and three-dimensional (3D) printing, we describe a protocol for manufacturing facemasks perfectly adapted to the individual face characteristics. The face specific mask was compared to a universal design of facemask and different filter container’s designs were merged with the mask body. Subjective assessment of the face specific mask demonstrated tight closure at the nose, mouth and chin area, and permits the normal wearing of glasses. A screw-drive locking system is advised for easy assembly of the filter components. Automation of the process enables high volume production but still allows sufficient designer interaction to answer specific requirements. The suggested protocol can be used to provide more comfortable, effective and sustainable solution compared to a single use, standardized mask. Subsequent research on printing materials, sterilization technique and compliance with international regulations will facilitate the introduction of the face specific mask in clinical practice as well as for general use.

Semi-automatic magnetic resonance imaging based orbital fat volumetry: reliability and correlation with computed tomography

Post-processing analysis can provide valuable information for diagnosis and planning of orbital disorders. This cross-sectional study aims to evaluate the reliability of semi-automatic, orbital fat volumetry using magnetic resonance imaging (MRI). Two observers assessed the orbital fat volume using a standard MRI protocol (3T, T1w sequence) in 12 orbits diagnosed with Graves' orbitopathy (GO) and 10 healthy control orbits. MRI and computed tomography (CT) based analysis were compared. Intra-observer variability was good (intraclass correlation coefficient (ICC) 0.88; 95% confidence interval (CI) [0.70, 0.95]) and interobserver agreement was moderate (ICC 0.55; 95% CI [-0.09, 0.81]), which corresponds to a mean percentage difference of 1.3% and 17.9% of the total orbital fat volume. Mean differences between MRI and CT measurements were, respectively, 1.1 cm³ (P= 0.064, 95% CI [-0.20, 2.43]) and 1.4 cm³ (P=0.016, 95% CI [0.21, 2.56]) for the control and the GO group. MRI volumetry was strongly correlated with CT (Pearson's r= 0.7, P<0.001). We conclude that orbital fat volumetry is feasible with a semi-automatic segmentation procedure and standard MRI protocol. Correlation with CT volumetry is good, but considerable bias may derive from observer variability and these errors should be taken into account for the purpose of volumetric analysis. Better definition of error sources may increase measurement accuracy.

Digital surface scanning in flap perfusion

Monitoring vascular perfusion of transferred tissue is essential in reconstructive surgery to recognize early flap failure. The aim of this study was to evaluate the ability of a digital surface scanner to detect vascular perfusion disorders through the monitoring of skin colour changes. A total of 160 surface scans of the forearm skin were performed with a TRIOS 3D scanner. Vascular compromise was simulated at different time-points by intermittent occlusion of the blood supply to the forearm skin (first the arterial blood supply and then the venous blood supply). Skin colour changes were examined according to the hue, saturation, and value colour scale. Colour differences were analysed with a paired t-test. Significant differences were observed between the colour of the normal skin and that of the vascular compromised skin (P<0.01). The surface scanner could distinguish between arterial occlusion and venous congestion (P<0.01). A digital surface scan is an objective, non-invasive tool to detect early vascular perfusion disorders of the skin.

Three-dimensional characterisation of the globe position in the orbit

PURPOSE

Current methods to analyse the globe position, including Hertel exophthalmometry and computed tomography (CT), are limited to the axial plane and require the lateral orbital rim and cornea as landmarks. This pilot study aimed to design a method to measure the position of the globe in the axial, coronal and sagittal plane and independent from orbital bony and corneal references.

METHODS

With the aid of three-dimensional CT reconstruction technology, we determined the globe position in the orbit based on the centre of the globe. Method validation was performed using data of consecutive orbital CT scans from the control group and from the patients with Graves' orbitopathy who underwent orbital decompression surgery with removal of the lateral orbital margin.

RESULTS

The inter- and intra-observer reliability was excellent with a high intraclass correlation coefficient (> 0.99, 95% CI [0.97; 1.00]). In the decompressed orbits, there was a statistically significant globe position shift along the anterior-posterior axis (P = 0.0005, 95% CI [0.63; 3.66]), but not along the medial-lateral and superior-inferior axis.

CONCLUSION

The 3D CT method can accurately and reliably characterise the globe position shift in the three dimensions without using orbital and corneal anatomical landmarks. The method can be useful to determine the globe shift in proptosis, enophthalmos, hypoglobus and hyperglobus, even in the presence of strabismus and orbital bone defects.

De novo variants in CDK13 associated with syndromic ID/DD: Molecular and clinical delineation of 15 individuals and a further review

De novo variants in the gene encoding cyclin-dependent kinase 13 (CDK13) have been associated with congenital heart defects and intellectual disability (ID). Here, we present the clinical assessment of 15 individuals and report novel de novo missense variants within the kinase domain of CDK13. Furthermore, we describe 2 nonsense variants and a recurrent frame-shift variant. We demonstrate the synthesis of 2 aberrant CDK13 transcripts in lymphoblastoid cells from an individual with a splice-site variant. Clinical characteristics of the individuals include mild to severe ID, developmental delay, behavioral problems, (neonatal) hypotonia and a variety of facial dysmorphism. Congenital heart defects were present in 2 individuals of the current cohort, but in at least 42% of all known individuals. An overview of all published cases is provided and does not demonstrate an obvious genotype-phenotype correlation, although 2 individuals harboring a stop codons at the end of the kinase domain might have a milder phenotype. Overall, there seems not to be a clinically recognizable facial appearance. The variability in the phenotypes impedes an à vue diagnosis of this syndrome and therefore genome-wide or gene-panel driven genetic testing is needed. Based on this overview, we provide suggestions for clinical work-up and management of this recently described ID syndrome.

Association of the missense variant p.Arg203Trp in PACS1 as a cause of intellectual disability and seizures

Graphical abstract key: ADHD, attention deficit hyperactivity disorder; ASD, atrial septal defect; DD, developmental delay; EEG, electroencephalogram; Ht, height; ID, intellectual disability; OCD, obsessive-compulsive disorder; OFC, open fontanelle; PDA, patent ductus arteriosis; PFO, patent foramen ovale; VSD, ventricular septal defect; Wt, weight.

Growth kinetics of gel-immobilized yeast cells studied by on-line microscopy

A 'microscope reactor' was used to study on-line the dynamics of gel immobilized cell systems. The applicability of the reactor is demonstrated by a study of the growth kinetics of Saccharomyces cerevisiae entrapped in 2% calcium alginate. The specific growth rates of single immobilized cells and free cells were measured. The growth of a microcolony in Ca-alginate was followed and the specific growth rate of the cells in the microcolony determined. A simple growth model was used to estimate the cell volume fraction of the yeast cells in the microcolony. As internal and external mass transfer limitations can be neglected and immobilized cell growth rates were found to be identical to those of free cells, one may conclude that immobilization does not influence cell growth under our experimental conditions.