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A 9-year-old girl is presented who was initially misdiagnosed and finally diagnosed with fibrodysplasia ossificans progressiva only after presentation with progressive limitation of her mouth opening. The clinical, histopathological, and molecular biological aspects of this uncommon disorder will be discussed. Furthermore, dental and surgical guidelines will be described. [ABSTRACT FROM AUTHOR]

This study aimed to identify and quantify the variations in PSI designs intended for an identical patient. Records from 10 patients with an orbital fracture involving two walls, for which a primary orbital reconstruction was indicated, were retrospectively included. Clinical engineers from two centers independently generated proposal designs for all patients. Following web meeting(s) with the surgeon from the same institute, the PSI designs were finalized by the engineer. A cross-over of the engineer with the surgeon of the other center created two new design teams. In total, 20 proposal and 40 final PSI designs were produced. A three-dimensional comparison between different PSI designs for the same patient was performed by computing a difference score. Initially, the design proposals of the two engineers showed a median difference score of 37%, which was significantly reduced to a median difference score of 26% for the final designs with different engineers. The median difference score of 22% between surgeons demonstrated that both parties introduced notable user variations to the final designs. Evidence supporting the advantages of an experienced design team was found, with significantly fewer modifications, fewer meetings, and less time required to complete the design (up to 40% time reduction). The findings of the study underline the dependency of PSI design on the surgeon and engineer, and support the need for a more evidence-based protocol for PSI design., Competing Interests: Declaration of competing interest The authors declare they have no conflicts of interest., (Copyright © 2024. Published by Elsevier Ltd.)

The available reference data for the mandible and mandibular growth consists primarily of two-dimensional linear or angular measurements. The aim of this study was to create the first open-source, three-dimensional statistical shape model of the mandible that spans the complete growth period. Computed tomography scans of 678 mandibles from children and young adults between 0 and 22 years old were included in the model. The mandibles were segmented using a semi-automatic or automatic (artificial intelligence-based) segmentation method. Point correspondence among the samples was achieved by rigid registration, followed by non-rigid registration of a symmetrical template onto each sample. The registration process was validated with adequate results. Principal component analysis was used to gain insight in the variation within the dataset and to investigate age-related changes and sexual dimorphism. The presented growth model is accessible globally and free-of-charge for scientists, physicians and forensic investigators for any kind of purpose deemed suitable. The versatility of the model opens up new possibilities in the fields of oral and maxillofacial surgery, forensic sciences or biological anthropology. In clinical settings, the model may aid diagnostic decision-making, treatment planning and treatment evaluation., Competing Interests: Declaration of competing interest Several grants were obtained by the MAGIC research consortium throughout the course of this study. In all cases, the ultimate purpose and motivation behind receiving these grants was to create an open-source mandibular growth model. Grant issuers were not able to review or control study design and data collection, had no part in the analysis and interpretation of the data, nor in writing the report or the decision to submit the article for publication., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Imaging with bone scans plays an important role in the diagnostic path of patients with unilateral condylar hyperactivity or unilateral condylar hyperplasia (UCH). The aim of this study is to perform a systematic review of the diagnostic performance of the bone SPECT and SPECT/CT scan for the diagnosis of UCH. PubMed, SCOPUS and EMBASE were searched electronically to identify diagnostic accuracy studies that assessed the diagnostic value of bone SPECT and SPECT/CT for the diagnosis of UCH, Meta-analyses were performed with Metadisc 1.4 and 2.0. A total of 14 studies, with a total number of 887 patients, were included in the qualitative analysis and 11 studies qualified for meta-analyses. The pooled sensitivity and specificity for the SPECT scan were 0.814 (95 % CI: 0.639-0.915) and 0.774 (95 % CI: 0.655-0.861), for the SPECT/CT scan these were 0.818 (95 % CI: 0.749-0.874) and 0.901 (95 % CI: 0.840-0.945). The summary receiver operating characteristics of the SPECT scan showed an area under the curve of 0.847 (95 % CI: 0.722-0.972) and that of the SPECT/CT scan was 0.928 (95 % CI: 0.876-0.980). CONCLUSION: Both bone SPECT scan and SPECT/CT scan provide a high diagnostic accuracy for UCH. The added value of the SPECT/CT scan is questionable and given the potential disadvantages of the SPECT/CT scan, including the increased radiation dose and costs, the diagnostic modality of first choice in patients with UCH should be a SPECT scan., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The primary aim of this study was to provide a review of the types and frequency of orthodontic brackets, molar bands and orthodontic auxiliaries used for patients undergoing orthognathic surgery. The secondary aim was to evaluate the risk of failure of these items during orthognathic surgery., Methods: From three Dutch hospitals, 124 adult patients were included in this prospective cohort study. Five independent researchers collected the data during surgery using a specifically created data extraction form. The type of surgery, surgeon, orthodontist and type of orthodontic bracket, molar band or auxiliary were noted for each tooth. To evaluate their failure risk, the following variables were noted: failure and site; and type and cause of failure., Results: Stainless-steel brackets were the most frequently (75.8%) used bracket type seen in patients undergoing orthognathic surgery. Ceramic brackets were seen in 24.2% of the cases and were only applied in the anterior region. Molar bands were present in 58.9% of the patients and mostly with bands on the first molars in combination with bonded tubes on the second molars. In 32.2% of all cases, one or more failures were noted. One-third of all failures were described as detachment of the molar tube on the most posterior molar. Kobayashi ligatures and powerpins showed the highest risk of failure (odds ratio [OR] 3.70, 95% confidence interval [CI] = 1.91-7.15). No significant difference in failure rate was found between stainless-steel brackets, molar bands (OR 0.34, 95% CI = 0.08-1.43) and ceramic brackets (OR 0.44, 95% CI = 0.14-1.45)., Conclusion: Stainless-steel brackets, ceramic brackets, molar bands and surgical hooks are suitable for orthognathic cases. Kobayashi ligatures and powerpins had a significantly higher risk of failure so are not recommended for temporary intraoperative maxillomandibular fixation (TIO-MMF)., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To explore the relationship between the volumetric bone mineral density (vBMD), the thickness of the condylar cortex (T cortex ) and the hemimandibular volumes (V hemimandible ) of symmetrical and asymmetrical mandibles of children., Design: The data collection consisted of 92 archeological skeletal remains of children's mandibles between 1 and 12 years old. The mandibles were digitalized with a computed tomography (CT) scan, and three dimensional models were obtained. V hemimandible was calculated using the optimal symmetry plane. The volumes were used to calculate the asymmetry index (AI). Mandibles with an AI of ≥ 3% (N = 9) and a sample of the most symmetrical mandibles (N = 9) were selected for this research. Three groups were created: a symmetrical, an asymmetrical and a pooled group. Micro-CT was used to measure the vBMD and T cortex in four volumes of interest. The AI was calculated for these parameters as well., Results: Significant correlations were found between the vBMD and the T cortex in the pooled group (P < .01) and between the AI of the vBMD and the AI of the T cortex in the pooled (P < .01) and symmetrical group (P < .05). No significant correlations were found between the vBMD and the V hemimandible and between the respective AIs. Between the T cortex and the V hemimandible a significant correlation was found in the pooled and asymmetrical group., Conclusion: There is a relationship between the vBMD and the T cortex . The correlations between the T cortex and the V hemimandible are insufficient to draw firm conclusions. A relationship between the vBMD and V hemimandible was not confirmed in this study., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The aim of this study is to validate the Dutch version of the Orthognathic Quality of Life Questionnaire (OQLQ-NL) for cleft patients who received orthognathic surgery., Methods: To compare the OQLQ-NL with the CLEFT-Q, we used a convenience sample of thirty-two cleft patients. Using the Cronbach's alpha coefficient for multiple item scales, internal reliabilities of the OQLQ-NL were evaluated. The OQLQ-NL was repeated at a two-week interval and the intraclass correlation coefficient was calculated, to establish of the test-retest reliability. The construct validity of the OQLQ-NL was evaluated by using Spearman's correlation to test its correlation with the CLEFT-Q., Results: Thirty-two patients filled in the OQLQ-NL and CLEFT-Q. The OQLQ-NL had excellent results in internal reliability and test-retest reliability. The vast majority of the correlations between the domains and scales of the questionnaires were as expected. Data from this study and previous studies confirm the construct validity of the OQLQ-NL., Conclusion: Our results suggest the OQLQ-NL is a valid and reliable instrument for measuring quality of life in cleft patients who have received orthognathic surgery in the Netherlands., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: The severity of craniofacial microsomia (CFM) is generally classified using the Orbit, Mandible, Ear, Soft tissue, Nerve (OMENS) classification score. The global assessment of the Phenotypic Assessment Tool for Craniofacial Microsomia (PAT-CFM), is a pictorial modification of the OMENS classification. The aim of this study was to assess the interrater reliability of the PAT-CFM global assessment score., Design: In this prospective cohort study, three clinicians completed the global assessment form of the PAT-CFM. The mandible was classified based on orthopantomogram- and/or computed tomography images., Participants: Consecutive patients with CFM or microtia., Interrater agreement was calculated using the weighted Krippendorff alpha (α), with 95% confidence intervals (CI)., Results: In total, 53 patients were included (106 hemifaces). The reliabilities of the main classification components ranged from high for the mandible (α = 0.904 [95% CI 0.860-0.948]) and ear (α = 0.958 [95% CI 0.934-0.983]) subscales, to tentative for the orbital summary score (α = 0.682 [0.542-0.821]), and nerve summary score (α = 0.782 [0.666-0.900]) subscales., Conclusions: The reliability of the ear and radiographic mandible scales of the PAT-CFM global classification were high, while the orbit, facial nerve and soft tissue subscales may have limited reliability. Research focusing on radiographic severity scores for hypoplasia of the orbits and soft tissues, as well as objective measures for overall facial hypoplasia using non-ionizing forms of imaging for early classification, are warranted., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

This retrospective study aimed to: (1) investigate the surgical accuracy of maxillomandibular advancement (MMA) in obstructive sleep apnea (OSA) patients, with a specific focus on maxillary and mandibular advancement and counter-clockwise rotation and (2) investigate the correlation between the amount of achieved advancement and the reduction in the relative apnea hypopnea index (AHI). Sixteen patients, for whom a three-dimensional virtual surgical plan was generated preoperatively and a computed tomography scan (CT) or cone-beam computer tomography (CBCT) was acquired postoperatively, were included. The postoperative CT or CBCT was compared to the virtual surgical plan, and differences in the mandibular and maxillary advancement and counter-clockwise rotation were assessed. Maxillary and mandibular advancement (median 3.1 mm, p = 0.002 and 2.3 mm, p = 0.03, respectively) and counter-clockwise rotation (median 3.7°, p = 0.006 and 4.7°, p = 0.001, respectively) were notably less than intended. A significant correlation was found between the planned maxillary advancement and the difference between the planned and actual maxillary advancement ( p = 0.048; adjusted R 2 = 0.1979) and also between the planned counter-clockwise rotation and the difference between the planned and actual counter-clockwise rotation for the mandible ( p = 0.012; adjusted R 2 = 0.3261). Neither the maxilla-first nor the mandible-first surgical sequence proved to be superior in terms of the ability to achieve the intended movements ( p > 0.45). Despite a significant reduction ( p = 0.001) in the apnea hypopnea index (AHI) from a median of 62.6 events/h to 19.4 events/h following MMA, no relationship was found between the extent of maxillary or mandibular advancement and AHI improvement in this small cohort ( p = 0.389 and p = 0.387, respectively). This study underlines the necessity for surgeons and future research projects to be aware of surgical inaccuracies in MMA procedures for OSA patients. Additionally, further research is required to investigate if sufficient advancement is an important factor associated with MMA treatment outcome.

To (1) appraise current international classification and clinical management strategies for craniofacial microsomia (CFM) and microtia, and (2) to assess agreement with the European Reference Network "European Guideline Craniofacial Microsomia" recommendations on screening and monitoring., This was a cross-sectional online survey study. The survey consisted of 44 questions on demographics, diagnostics and classification, obstructive sleep apnea, feeding difficulties, speech and language development, hearing, ocular abnormalities, visual development, orthodontic screening, genetic counselling, psychological wellbeing, and extracraniofacial anomalies., Respondents were participants of 3 international cleft and craniofacial conferences, members of the American Cleft Palate and Craniofacial Association and members of the International Society for Auricular Reconstruction. Respondents were requested to complete 1 questionnaire per multidisciplinary team., Fifty-seven responses were received from 30 countries (response rate ∼3%).The International Consortium for Health Outcomes Measurement diagnostic criteria were used by 86% of respondents, though 65% considered isolated microtia a mild form of CFM. The Orbit, Mandible, Ear, Facial Nerve and Soft Tissue classification system was used by 74% of respondents. Agreement with standardized screening and monitoring recommendations was between 61% and 97%. A majority of respondents agreed with screening for extracraniofacial anomalies (63%-68%) and with genetic counselling (81%)., This survey did not reveal consistent agreement on the diagnostic criteria for CFM. Respondents mostly supported management recommendations, but frequently disagreed with the standardization of care. Future studies could focus on working towards international consensus on diagnostic criteria, and exploring internationally feasible management strategies.

Objective: To explore the normal variation of asymmetry in mandibles of children in the age group of 1 to 12 years., Materials and Methods: The study group consisted of 92 cadaveric mandibles of children with a dental age of 1 to 12 years old in possession of ACTA (Academic Centre for Dentistry Amsterdam), Faculty of Dentistry, the Netherlands. 3D models of the mandibles were obtained from CT-scans and hemimandibular volumes of all mandibles were calculated. The condylar height, ramus height, mandibular body length and the gonial angle were bilaterally determined using a novel landmark-based method, and the degree of asymmetry was calculated., Results: No relationship was found between dental age and asymmetry of the studied parameters (P < .05). The highest degree of asymmetry was found in the ramus height, whereas the gonial angle presented the lowest degree of asymmetry. A positive correlation was found between the asymmetry of the hemimandibular volume vs the height of the ramus (P < .05) and the length of the mandibular body (P < .05). An inverse correlation was found between the asymmetry of the ramus height vs the condylar height (P < .05), mandibular body length (P < .05) and gonial angle (P < .05)., Conclusions: Mandibular asymmetries in children did occur (9.8% of the included mandibles presented with a relevant overall asymmetry of ≥3%) and were unrelated to age. The different segments of the mandible seem to compensate for each other, in order to maintain a functional equilibrium., (© 2023 The Authors. Orthodontics & Craniofacial Research published by John Wiley & Sons Ltd.)

Background: The four different local therapy strategies used for head and neck rhabdomyosarcoma (HNRMS) include proton therapy (PT), photon therapy (RT), surgery with radiotherapy (Paris-method), and surgery with brachytherapy (AMORE). Local control and survival is comparable; however, the impact of these different treatments on facial deformation is still poorly understood. This study aims to quantify facial deformation and investigates the differences in facial deformation between treatment modalities., Methods: Across four European and North American institutions, HNRMS survivors treated between 1990 and 2017, more than 2 years post treatment, had a 3D photograph taken. Using dense surface modeling, we computed facial signatures for each survivor to show facial deformation relative to 35 age-sex-ethnicity-matched controls. Additionally, we computed individual facial asymmetry., Findings: A total of 173 HNRMS survivors were included, survivors showed significantly reduced facial growth (p < .001) compared to healthy controls. Partitioned by tumor site, there was reduced facial growth in survivors with nonparameningeal primaries (p = .002), and parameningeal primaries (p ≤.001), but not for orbital primaries (p = .080) All patients were significantly more asymmetric than healthy controls, independent of treatment modality (p ≤ .001). There was significantly more facial deformation in orbital patients when comparing RT to AMORE (p = .046). In survivors with a parameningeal tumor, there was significantly less facial deformation in PT when compared to RT (p = .009) and Paris-method (p = .007)., Interpretation: When selecting optimal treatment, musculoskeletal facial outcomes are an expected difference between treatment options. These anticipated differences are currently based on clinicians' bias, expertise, and experience. These data supplement clinician judgment with an objective analysis highlighting the impact of patient age and tumor site between existing treatment options., (© 2023 The Authors. Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

The primary aim of this study was to assess the association between clinical efficacy outcomes (i.e., polysomnography (PSG) results) of maxillomandibular advancement (MMA) and surgeons' experience. The second aim was to assess the association between the occurrence of postoperative complications of MMA and surgeons' experiences. Patients treated with MMA for moderate to severe obstructive sleep apnea (OSA) were enrolled in this retrospective study. The patient population was divided into two groups based on two different surgeons performing MMA. The associations between surgeons' experience on the one hand and PSG results and postoperative complications on the other hand were investigated. A total of 75 patients were included. There was no significant difference in baseline characteristics between the two groups. The reductions in apnea-hypopnea index and oxygen desaturation index were both significantly greater in group-B than group-A ( p = 0.015 and 0.002, respectively). The overall success rate after MMA was 64.0%. There was a negative correlation between surgeon experience and surgical success (odds ratio: 0.963 [0.93, 1.00], p = 0.031). No significant association was found between surgeon experience and surgical cure. Additionally, there was no significant association between surgeon experience and the occurrence of postoperative complications. Within the limitations of this study, it is concluded that surgeon experience may have little to no influence on the clinical efficacy and safety of MMA surgery in OSA patients.

In this study, 100 consecutive scheduled transoral condylectomies for unilateral condylar hyperplasia were included. The safety and surgical performances were assessed, using the operating time, conversion rate and complication rate. The conversion rate learning curve was evaluated with a learning curve cumulative summation (LC-CUSUM). The total conversion rate was 8.0%. The LC-CUSUM for conversion signaled at the 53th procedure, indicating sufficient evidence had accumulated that the surgeon had achieved competence. For procedures 54-100, the conversion rate was 4.0%. The operating time for the transoral condylectomy was 41.5 ± 15.3 min; when a conversion was necessary, the operating time was 101.4 ± 28.3 min (p < 0.05). The estimated operating time in the post-learning phase was 37 min, this was reached after approximately 47 procedures. There was 1 major complication of a permanent inferior alveolar nerve hypoesthesia. The complication rate was not significantly decreased after the learning curve. Within the limitations of the study, it seems that transoral condylectomy for UCH is a safe procedure with several advantages over the traditional preauricular approach. Surgeons starting this procedure should be aware of the potential complications and of the learning curve of approximately 53 procedures., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Measuring the impact of orthognathic surgery on quality of life is of significant importance in patients with cleft deformities. Standardized tools such as patient-reported outcome measures (PROMs) are needed to fully comprehend patients' needs and perceptions. Therefore, the availability of reliable, valid, and comprehensive questionnaires for patients is essential. The aim of this study is to identify PROMs measuring the impact of orthognathic surgery on quality of life in patients with cleft deformities and to evaluate the identified PROMs., A systematic search of the literature was performed according to the preferred reporting items for systematic reviews and meta-analysis guidelines. All validated PROMs, regarding the impact of orthognathic surgery on quality of life in patients with cleft deformities, were identified and assessed according to the quality criteria proposed for measurement properties of health status questionnaires., An electronic search yielded 577 articles. After a full-text review of 87 articles, 4 articles met the inclusion criteria, comprising 58 PROMs. Of these 58 PROMs, 1 PROM (the CLEFT-Q) has been validated to measure the impact of orthognathic surgery on patients with a facial cleft. Evaluation of methodological quality of the included articles and assessment of the measurement properties of the CLEFT-Q show that the CLEFT-Q scores relatively good for all available measurement properties, making it suitable for immediate use., The CLEFT-Q was found to be the only valid instrument so far to measure the impact of orthognathic surgery on the quality of life in patients with cleft deformities.

Orthognathic surgery in asymmetric cases is challenging because of diversity and individuality. Clinical observations are of paramount importance and need to be systemically thorough. Three-dimensional diagnosis and virtual planning have been proven extremely helpful in facilitating treatment toward symmetry in difficult cases with increasing precision. Compared with orthognathic surgery in symmetric situations, asymmetries produce numerous pitfalls and provide opportunities for out-of-the-box procedures., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Nuclear imaging plays an important role in the diagnostic path of patients with unilateral condylar hyperplasia (UCH). The purpose of this study was to determine the performance of single-photon emission computed tomography-computed tomography (SPECT-CT) in a large group of patients with suspected UCH. This study prospectively included 156 patients with a clinical presentation of progressive mandibular asymmetry. All patients underwent 99 m Tc-HDP SPECT-CT and extensive baseline and follow-up documentation. The relative activity of the ipsilateral condyle in relation to the contralateral condyle was calculated for both the mean and maximum count, and the diagnostic accuracy of different cut-off values was determined. The area under the receiver operating characteristic curve of the SPECT-CT scan was 0.892 for the mean count and 0.873 for the maximum count. The optimal cut-off of> 8% (SPECT-CT mean count) resulted in a sensitivity of 87.0% and a specificity of 88.6%. SPECT-CT showed good diagnostic performance in UCH; however the benefit of the CT scan is questionable and the potential disadvantages have to be weighed against the benefits when compared to standard SPECT scanning. When using SPECT-CT in the diagnostic path in UCH, a mean value cut-off of>8% for the relative activity between the condyles is most accurate., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Restoration of the orbit is the first and most predictable step in the surgical treatment of orbital fractures. Orbital reconstruction is keyhole surgery performed in a confined space. A technology-supported workflow called computer-assisted surgery (CAS) has become the standard for complex orbital traumatology in many hospitals. CAS technology has catalyzed the incorporation of personalized medicine in orbital reconstruction. The complete workflow consists of diagnostics, planning, surgery and evaluation. Advanced diagnostics and virtual surgical planning are techniques utilized in the preoperative phase to optimally prepare for surgery and adapt the treatment to the patient. Further personalization of the treatment is possible if reconstruction is performed with a patient-specific implant and several design options are available to tailor the implant to individual needs. Intraoperatively, visual appraisal is used to assess the obtained implant position. Surgical navigation, intraoperative imaging, and specific PSI design options are able to enhance feedback in the CAS workflow. Evaluation of the surgical result can be performed both qualitatively and quantitatively. Throughout the entire workflow, the concepts of CAS and personalized medicine are intertwined. A combination of the techniques may be applied in order to achieve the most optimal clinical outcome. The goal of this article is to provide a complete overview of the workflow for post-traumatic orbital reconstruction, with an in-depth description of the available personalization and CAS options.

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.

The aim of this study was to compare two techniques for temporary intraoperative maxillomandibular fixation (TIO-MMF) during orthognathic surgery: steel-wire ligatures versus power chains. Patients undergoing orthognathic surgery between October 2019 and March 2020 were included in a prospective cross-sectional study conducted in three participating hospitals. Data were collected using a standardized measurement form. A total of 44 patients were included, in whom TIO-MMF was applied 79 times. A statistically significant difference in intraoperative loss of stability of the segment relationship was found between steel-wire ligatures (11.4%) and power chains (0%). The mean application time of TIO-MMF differed significantly between steel-wire ligatures (99 seconds) and power chains (157 seconds) (P < 0.001). There was no statistical difference in occurrence of adverse events between the two techniques. This study found that the application of TIO-MMF with power chains is more stable compared to steel-wire ligatures. Steel-wire ligatures were significantly faster to apply, although the absolute difference (less than 1 minute) was small. Other possible advantages of the proposed technique are discussed. The results of this study suggest that power chains for the application of TIO-MMF in orthognathic surgery are a valuable alternative to steel-wire ligatures., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Abstract: Orbital reconstruction is one of the most complex procedures in maxillofacial surgery. It becomes even more complex when all references to the original anatomy are lost. The purpose of this article is to provide an overview of techniques for complex three- and four-wall orbital reconstructions. Preoperative virtual surgical planning is essential when considering different reconstruction possibilities. The considerations that may lead to different approaches are described, and the advantages and drawbacks of each technique are evaluated. It is recommended to reconstruct solitary three-wall or four-wall orbital defects with multiple patientspecific implants. Optimizations of this treatment protocol are suggested, and their effects on predictability are demonstrated in a case presentation of a four-wall defect reconstruction with multiple patient-specific implants., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

In orbital reconstruction, a patient-specific implant (PSI) may provide accurate reconstruction in complex cases, since the design can be tailored to the anatomy. Several design options may be embedded, for ease of positioning and precision of reconstruction. This study describes a cohort of 22 patients treated for secondary orbital reconstruction with a PSI; one patient received two PSI. The preoperative clinical characteristics and implant design options used are presented. When compared to preoperative characteristics, the postoperative clinical outcomes showed significant improvements in terms of enophthalmos (P < 0.001), diplopia (P < 0.001), and hypoglobus (P = 0.002). The implant position in all previous reconstructions was considered inadequate. Quantitative analysis after PSI reconstruction showed accurate positioning of the implant, with small median and 90th percentile deviations (roll: median 1.3°, 90th percentile 4.6°; pitch: median 1.4°, 90th percentile 3.9°; yaw: median 1.0°, 90th percentile 4.4°; translation: median 1.4 mm, 90th percentile 2.7 mm). Rim support proved to be a significant predictor of roll and rim extension for yaw. No significant relationship between design options or PSI position and clinical outcomes could be established. The results of this study show the benefits of PSI for the clinical outcomes in a large cohort of secondary post-traumatic orbital reconstructions., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

The treatment of young patients with missing teeth and an atrophied alveolar process after trauma or agenesis of a tooth can be challenging. The aim of this study was to evaluate autotransplantation of a premolar after pre-autotransplantation alveolar process augmentation (PAPA) as a treatment option for these patients. A retrospective cohort study was implemented to analyse the PAPA procedure and subsequent autotransplantation procedure. Alveolar process augmentation was performed using different types of autologous bone grafts. Subsequent autotransplantation of one or more premolars was performed approximately 4 months later. Nine patients with a mean age of 12 years were included. Twelve premolars were transplanted after a PAPA procedure: seven in the maxillary incisor region, four in the mandibular premolar region, and one in the mandibular incisor region. Initially all transplanted teeth functioned well. However, one mandibular premolar that was transplanted in the maxillary incisor region was lost because of resorption after 6 years of follow-up. The other 11 transplanted teeth functioned well. The mean follow-up was 6 years (range 3-13 years). The results showed that autotransplantation can be facilitated by PAPA with a high chance of success. It can therefore be a valuable addition to other existing treatment options., (Copyright © 2021 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that eliminates the need for a registration procedure altogether: registration-free navigation. In the workflow, the maxillary dental model is fused to the pre-operative imaging data using commercially available virtual planning software. A virtual Dynamic Reference Frame on a splint is designed on the patient's fused maxillary dentition: during surgery, the splint containing the reference frame is positioned on the patient's dentition. This alleviates the need for any registration procedure, since the position of the reference frame is known from the design. The accuracy of the workflow was evaluated in a cadaver set-up, and compared to bone-anchored fiducial, virtual splint and surface-based registration. The results showed that accuracy of the workflow was greatly dependent on tracking technique used: the workflow was the most accurate with electromagnetic tracking, but the least accurate with optical tracking. Although this method offers a time-efficient, non-invasive, radiation-free automatic alternative for registration, clinical implementation is hampered by the unexplained differences in accuracy between tracking techniques., (© 2021. The Author(s).)

Adequate positioning of an orbital implant during orbital reconstruction surgery is essential for restoration of the pre-traumatised anatomy, but visual appraisal of its position is limited by the keyhole access and protruding soft tissues. A positioning instrument that attaches to the implant was designed to provide feedback outside the orbit. The goal of this study was to evaluate the accuracy of placement with the instrument and compare it with the accuracy of placement by visual appraisal. Ten orbits in five human cadaver heads were reconstructed twice: once using visual appraisal and once using the instrument workflow. No significant improvement was found for the roll (5.8° vs 3.4°, respectively, p=0.16), pitch (2.1° vs 1.5°, p=0.56), or translation (2.9 mm vs 3.3 mm, p=0.77), but the yaw was significantly reduced if the instrument workflow was used (15.3° vs 2.9°, p=0.02). The workflow is associated with low costs and low logistical demands, and may prevent outliers in implant positioning in a clinical setting when intraoperative navigation or patient-specific implants are not available., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The aim of this study is to translate and validate the Orthognathic Quality of Life Questionnaire (OQLQ) in the Dutch language (OQLQ-NL)., Methods: The translation of the OQLQ into the Dutch language was performed following the guidelines for the Process of Cross-Cultural Adaption of Self-Report Measures. Sixty-two patients who received orthognathic surgery in the past 10 years were included for participation. Internal reliabilities of the OQLQ-NL were evaluated for multiple item scales with the use of the Cronbach alpha coefficient. For the establishment of the test-retest reliability, the OQLQ-NL was repeated with a 2-week interval and the intraclass correlation coefficient was calculated. Spearman correlation was used to test the correlation with the OHIP-49NL and the FACE-Q, to be able to evaluate the construct validity of the OQLQ-NL., Results: Thirty-five patients filled in the OQLQ-NL, OHIP49NL, and FACE-Q upon arrival and 22 patients returned the OQLQ-NL after 2 weeks (response rate of 56.6% and 62.9%, respectively). The OQLQ-NL showed excellent results in internal reliability and test-retest reliability. The vast majority of the correlations between the domains of the questionnaires were as expected. Data from this study and previous studies confirm the construct validity of the OQLQ-NL., Conclusion: The OQLQ-NL appears to be a valid and reliable instrument to measure quality of life for patients receiving orthognathic surgery in the Netherlands., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

In intra-operative navigation, a registration procedure is performed to register the patient's position to the pre-operative imaging data. The registration process is the main factor that determines accuracy of the navigation feedback. In this study, a novel registration protocol for craniofacial surgery is presented, that utilizes a virtual splint with marker points. The accuracy of the proposed method was evaluated by two observers in five human cadaver heads, for optical and electromagnetic navigation, and compared to maxillary bone-anchored fiducial registration (optical and electromagnetic) and surface-based registration (electromagnetic). The results showed minimal differences in accuracy compared to bone-anchored fiducials at the level of the infra-orbital rim. Both point-based techniques had lower error estimates at the infraorbital rim than surface-based registration, but surface-based registration had the lowest loss of accuracy over target distance. An advantage over existing point-based registration methods (bone-anchored fiducials, existing splint techniques) is that radiological imaging does not need to be repeated, since the need for physical fiducials to be present in the image volume is eradicated. Other advantages include reduction of invasiveness compared to bone-achnored fiducials and a possible reduction of human error in the registration process.

Competing Interests: Disclosure The authors have nothing to disclose.

Competing Interests: Disclosure In the submission process, in kind funding was declared. In all these studies, Brainlab provided the navigation equipment in kind, while KLS Martin provided the preformed orbital implants in kind. Additionally, for the real-time navigation, Brainlab provided the IGT link license in kind. KLS Martin provided the instrument in kind. This sub-project was supported by the S.O.R.G. Research Grant Award 2017.

Orthognathic surgery is a widely performed procedure to correct dentofacial deformities. Virtual treatment planning is an important preparation step. One advantage of the use of virtual treatment planning is the possibility to assess the accuracy of orthognathic surgery. In this study, a tool (OrthoGnathicAnalyser 2.0), which allows for quantification of the accuracy of orthognathic surgery, is presented and validated. In the OrthoGnathicAnalyser 2.0 the accuracy of the osseous chin can now be assessed which was not possible in the earlier version of the OrthoGnathicAnalyser. 30 patients who underwent bimaxillary surgery in combination with a genioplasty were selected from three different centers in the Netherlands. A pre-operative (CB)CT scan, virtual treatment planning and postoperative (CB)CT scan were required for assessing the accuracy of bimaxillary surgery. The preoperative and postoperative (CB)CT scans were aligned using voxel-based matching. Furthermore, voxel-based matching was used to align the pre-operative maxilla, mandible and rami towards their postoperative position whereas surface-based matching was used for aligning the pre-operative chin towards the postoperative position. The alignment resulted in a transformation matrix which contained the achieved translations and rotations. The achieved translations and rotations can be compared to planning values of the virtual treatment plan. To study the reproducibility, two independent observers processed all 30 patients to assess the inter-observer variability. One observer processed the patients twice to assess the intra-observer variability. Both the intra- and inter-observer variability showed high ICC values (> 0.92) and low measurement variations (< 0.673±0.684mm and < 0.654±0.824°). The results of this study show that the OrthoGnathicAnalyser 2.0 has an excellent reproducibility for quantification of skeletal movements between two (CB)CT scans., Competing Interests: The authors have declared that no competing interests exist.

Unilateral condylar hyperplasia (UCH) causes progressive asymmetry of the mandible. The aetiology of this growth disorder is unknown. A two-centre prospective study was established, and 10 consecutive adult UCH patients scheduled for high condylectomy were included. The resected condylar tissue was divided into two parts, one for regular histopathology and one for DNA extraction. A panel of eight selected overgrowth genes (AKT1, AKT3, MTOR, PIK3CA, PIK3R2, PTEN, TSC1, TSC2) were sequenced using next-generation sequencing, with coverage of a minimum 500 times in order to be able to detect low-grade mosaicisms. Subsequently, untargeted whole exome sequencing (WES) was performed to detect variants in other genes present in three or more patients. No mutation was detected in any of the overgrowth genes, and untargeted exome sequencing failed to detect any definitively causative variant in any other gene. Ten genes had a rare variant in three or more patients, but these cannot be designated as causative without additional functional studies. The hypothesis that the cause in at least some patients with UCH is a somatic mutation in a gene that controls cell growth could not be confirmed in this study., (Copyright © 2020. Published by Elsevier Ltd.)

Intraoperative imaging enables the surgeon to control the position of the implant during orbital reconstruction. Although it might improve surgical outcome and avoid the need for revision surgery, it may also increase the duration of the operation and the exposure to radiation. The goal of this study was to find out whether intraoperative imaging improves the position of the implant in reconstructions of the orbital floor and medial wall. Two surgeons reconstructed complex orbital fractures in 10 cadavers. After the reconstruction a computed tomographic scan was made to confirm the position of the implant and, if required, to make any adjustments. Scans were repeated until the surgeon was satisfied. The ideal position was ascertained by scans that were obtained before and after creation of the fractures. The position of the implant achieved was compared with that of the ideal position of the implant, and improved significantly for yaw (p=0.04) and roll (p=0.03). A mean of 1.6 scans was required for each reconstruction (maximum n=3). The main reason for alteration was the rotation roll. Intraoperative imaging significantly improves the position of the implant in fractures of the orbital floor and medial wall. The surgeon has quality control of its position during the reconstruction to restore the anatomical boundaries., (Copyright © 2020 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: This study presents the results of an updated clinical protocol for orbital blow-out fractures, with a special emphasis on nonsurgical treatment and orthoptic evaluation of functional improvement., Methods: A two-centre multidisciplinary prospective cohort study was designed to monitor the results of a clinical protocol by assessing ductions, diplopia, globe position, and fracture size. Patients underwent clinical assessment and orthoptic evaluation at first presentation and then at 2 weeks and 3/6/12 months after nonsurgical or surgical treatment. Outcome parameters were field of binocular single vision (BSV), ductions, degree of enophthalmos, a diplopia quality-of-life (QoL) questionnaire, and other sequelae or surgical complications., Results: 46 of the 58 patients who completed the 3, 6 and/or 12-month follow-up received nonsurgical treatment. There was full recovery without diplopia or enophthalmos (>2 mm) in 45 of the 58 patients. The other 13 patients had limited diplopia, mainly in extreme upward gaze (average BSV 90). Five of those 13 patients did not experience impairment of diplopia in daily life. The average QoL score at the end of follow-up was 97. No patients developed late enophthalmos., Conclusion: This study showed that a high percentage of patients with orbital floor and/or medial wall fracture recovered spontaneously without lasting diplopia or cosmetically disfiguring enophthalmos. The conservative treatment protocol assessed here underlines the importance of orthoptic evaluation of functional parameters., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The aim of this pilot study was to evaluate the accuracy and predictability of a splintless treatment protocol for edentulous patients undergoing orthognathic surgery in four consecutive cases. All operations were virtually planned, followed by computer-aided design of individual osteotomy guides and patient-specific fixation implants, which were three-dimensionally printed in titanium. In order to evaluate the discrepancy between the planned and the achieved postoperative result, the postoperative outcome was compared to the virtual treatment plan. Rotational and translational movement and discrepancies with the planned movements were quantified for the maxilla; the advancement was quantified for the mandible. For the maxilla, there was a mean translation discrepancy of 0.6mm. With regard to rotation, there was a mean discrepancy of 1.9°, 0.1°, and 0.4° for pitch, yaw, and roll, respectively. The mean discrepancy in translation of the mandible was 0.4mm. The results of this pilot study indicate that the splintless treatment protocol for orthognathic surgery in edentulous patients presented here is accurate and predictable., (Copyright © 2019 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and translate it to desired adjustments of the implant's position. In a previous study, a real-time implant-oriented navigation approach was introduced and the system's accuracy was evaluated. In this study, this real-time navigation approach was compared to a marker-based navigation approach in a preclinical set-up. Ten cadavers (20 orbital defects) were reconstructed twice, by two surgeons (total: 80 reconstructions). Implant positioning was significantly improved in the real-time implant-oriented approach in terms of roll (2.0° vs. 3.2°, P=0.03), yaw (2.2° vs. 3.4°, P=0.01) and translation (1.3mm vs. 1.8mm, P=0.005). Duration of the real-time navigation procedure was reduced (median 4.5 min vs. 7.5 min). Subjective appreciation of the navigation technique was higher for real-time implant-oriented navigation (mean 7.5 vs. 9.0). Real-time implant-oriented navigation feedback provides real-time, intuitive feedback to the surgeon, which leads to improved implant positioning and shortens duration of the navigation procedure., (Copyright © 2019. Published by Elsevier Ltd.)

Background: Cutaneous squamous cell carcinoma (cSCC) is a common type of malignant skin disorder. An uncommon feature is local bony invasion, as can rarely be seen in lesions on the scalp. The optimal treatment strategy in these rare cases is still under debate., Objective: The aim of this case report is to present a 1-stage three-dimensional planned surgical resection and reconstruction of a cSCC with bony invasion into the scalp and to discuss the alternative options and potential pitfalls., Materials and Methods: A patient diagnosed with rT4N0M0 cSCC of the scalp underwent a cranial resection and reconstruction in 1 stage. With the use of computer-assisted design and computer-assisted manufacturing a patient-specific implant (PSI) of poly (ether ether ketone) was manufactured. After the PSI was inserted, it was covered with a latissimus dorsi muscle and a split-thickness skin graft., Results: Intraoperatively the resection template generated an accurate resection and accurate and fast placement of the PSI. The reconstruction had a clinical satisfactory esthetic result, but was hampered by the development of a small wound dehiscence was observed over the postoperative course., Conclusion: Three-dimensional planned resection and reconstruction for composite defects of the skull after resection of a cSCC of the scalp with bony invasion may lead to an accurate and predictable resection and accurate and fast placement of the PSI. However, patient specific characteristics should be considered to assess potential risks and benefits before opting for this one-stage treatment strategy.

Purpose: Cranioplasty is customary after decompressive craniectomy. Many different materials have been developed and used for this procedure. The ideal material does not yet exist, while complication rates in cranioplasties remain high. This study aimed to determine factors related to autologous bone flap failure., Materials and Methods: In this two-center retrospective cohort study, 276 patients underwent autologous bone cranioplasty after initial decompressive craniectomy between 2004 and 2014. Medical records were reviewed regarding patient characteristics and factors potentially related to bone flap failure. Data were analyzed using univariable and multivariable regression analysis., Results: Independent factors related to overall bone flap failure were: duration of hospitalization after decompressive craniectomy [OR: 1.012 (95%CI: 1.003-1.022); p = 0.012], time interval between decompressive craniectomy and cranioplasty [OR: 1.018 (95%CI: 1.004-1.032); p = 0.013], and follow-up duration [OR: 1.034 (95%CI: 1.020-1.047); p < 0.001]. In patients with bone flap infection, neoplasm as initial diagnosis occurred significantly more often (29.2% vs. 7.8%; RD 21.3%; 95%CI 8.4 -38.3%; NNH 5; 95%CI 3 -12) and duration of hospitalization after decompressive craniectomy tended to be longer (means 54 vs. 28 days, MD 26.2 days, 95%CI -8.6 to 60.9 days). Patients with bone flap resorption were significantly younger (35 vs. 43 years, MD 7.7 years, 95%CI 0.8-14.6 years) and their cranial defect size tended to be wider than in patients without bone flap resorption (mean circumference 39 vs. 37 cm; MD 2.4 cm, 95% CI -0.43-5.2 cm) and follow-up duration was significantly longer (44 vs. 14 months, MD 29 months, 95%CI 17-42 months)., Conclusion: A neoplasm as initial diagnosis, longer hospitalization after decompressive craniectomy, larger time interval between decompressive craniectomy and cranioplasty, and longer follow-up duration are associated with a higher risk of failure of autologous bone flaps for cranioplasty. Patients with these risk factors may be better served with an early recovery program after decompressive surgery or an alloplastic material for cranioplasty., (Copyright © 2019. Published by Elsevier Ltd.)

Purpose: The aim of this study was to evaluate the accuracy of resection templates in cranioplasties in order to facilitate a one-stage resection and cranial reconstruction., Patients and Methods: In three cases, cranial resections were combined with direct reconstructions using the principles of computer-aided design, manufacturing, and surgery. The precision of the resection template was evaluated through a distance map, comparing the planned and final result., Results: The mean absolute difference between the planned and actual reconstructed contour was less than 1.0 mm. After 3 years, no clinical signs of infection or rejection of the implants were present. The computed tomography scans showed no irregularities, and the aesthetic results remained satisfactory., Conclusion: One-stage resection and cranial reconstruction using a resection template, control template, and a prefabricated patient-specific implant of poly(ether-ether-ketone) (PEEK) proved to be a viable and safe method., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)