Facial deformation following treatment for pediatric head and neck rhabdomyosarcoma; the difference between treatment modalities. Results of a trans-Atlantic, multicenter cross-sectional cohort study.

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.

Initial UK series of endoscopic suturectomy with postoperative helmeting for craniosynostosis: early report of perioperative experience.

BACKGROUND: Endoscopic suturectomy with postoperative helmeting (ESCH) has emerged as a successful treatment for craniosynostosis, initially in North America. We report early outcomes from the first cohort of ESCH patients treated in the United Kingdom (UK). METHODS: Retrospective cohort study with electronic chart review. RESULTS: 18 consecutive patients from the first ESCH procedure in UK (May 2017) until January 2020 identified. 12 male and 6 female infantsd, with a mean age of 4.6 months (range 2.5-7.8 months) and weight of 6.8 kg (range 4.8-9.8 kg). Diagnoses were metopic (n = 8), unicoronal (n = 7), sagittal (n = 2) and multi-sutural (n = 1) synostoses. Median incision length was 3 cm (range 2-10 cm). 16/18 received no blood products, with 2 (both metopics) requiring transfusion (1 donor exposure). Mean operative time (including anaesthesia) was 96 min (range 40-127 min). Median length of hospital stay was 1 night. 1 surgical complication (superficial infection). All patients are currently undergoing helmet orthosis therapy. So far, no patients have required revisional or squint surgery. CONCLUSION: Early experience from the first UK cohort of ESCH suggests that this is a safe and well tolerated technique with low morbidity, transfusion and short hospital stay. Long-term results in terms of shape, cosmetic and developmental outcome are awaited.

3-Dimensional Morphometric Outcomes After Endoscopic Strip Craniectomy for Unicoronal Synostosis.

BACKGROUND: Endoscopic strip craniectomy with postoperative helmeting (ESCH) for unicoronal synostosis has shown to be a less morbid procedure when compared with fronto-orbital remodeling (FOR). We aim in this pilot study to report objective methods and quantitative morphologic outcomes of endoscopically treated unicoronal synostosis using 3-dimensional surface scans. METHODS: Our electronic records were reviewed for ophthalmological, neurodevelopmental outcomes, and helmet-related complications. For morphologic outcomes, the following parameters were used: Cranial Index, Cranial Vault Asymmetry Index, Anterior Symmetry Ratio (ASR), and Root Mean Square between the normal and synostotic sides of the head. Three-dimensional stereophotogrammetry scans were evaluated at 3 time points preoperative, 6 months post-op, and at the end of the treatment, which was compared with age-matched scans of normal controls and FOR patients. Nonparametric tests were used for statistical analysis. RESULTS: None of the ESCH cases developed strabismus, major neurodevelopmental delay, or helmet complications. All morphologic parameters improved significantly at 6 months post-op except for the Cranial Vault Asymmetry Index. The ASR was the only parameter to change significantly between 6 months post-op and final scans. At end of helmet treatment, ASR and Root Mean Square differed significantly between the ESCH and both FOR and control groups. CONCLUSIONS: Endoscopic strip craniectomy with postoperative helmeting for single unicoronal synostosis had excellent clinical outcomes. Most of the improvement in head morphology occurred in the first 6 months of treatment. Despite the normalization of the overall head shape, there was residual asymmetry in the frontal and temporal regions of the head.

Does the Mutation Type Affect the Response to Cranial Vault Expansion in Children With Apert Syndrome?

LEVEL OF EVIDENCE: III.

Multiparametric Imaging for Presurgical Planning of Craniopagus Twins: The Experience of Two Tertiary Pediatric Hospitals with Six Sets of Twins.

Conjoined twins are rare and pose a challenge to radiologists and surgeons. Craniopagus twins, where conjunction involves the cranium, are especially rare. Even in large pediatric centers, radiologists are unlikely to encounter more than one such event in their medical careers. This rarity makes it daunting to select a CT and MRI protocol for these infants. Using the experience of two tertiary pediatric hospitals with six sets of craniopagus twins, this multidisciplinary and multimodal integrated imaging approach highlights the key questions that need addressing in the decision-making process for possible surgical intervention.

Skull fractures in abusive head trauma: a single centre experience and review of the literature.

PURPOSE: The authors provide a comprehensive framework with which to approach paediatric calvarial injury sustained as a result of suspected abusive head trauma (AHT). This is achieved through the presentation of a case series set in the context of the unique morphology of the infant skull and the possible diagnostic pitfalls which may arise due to the presence of variant anatomy or other mimicking conditions. METHODS: A retrospective analysis of sixty-three patients referred to our institution with suspected AHT was carried out. Seventeen patients with skull fractures were identified and their fractures were described in terms of anatomical location, type and course. Our data was then interpreted in the light of known anatomical fracture mimics and the available literature on the subject. RESULTS: Forty-two skull fractures were identified and described in our cohort, most of which were simple linear fractures of the parietal bones (33%). There were also a substantial number of complex stellate fractures, namely of the parietal (29%) and occipital (10%) bones. Eleven fracture mimics including accessory sutures and wormian bones were also identified in this cohort. CONCLUSIONS: Our study supports and builds on the existing literature, thereby offering a more complete view of the spectrum of calvarial damage sustained as a result of AHT in the context of its diagnostic pitfalls.

Sporting activity after craniosynostosis surgery in children: a source of parental anxiety.

PURPOSE: Craniosynostosis correction involves major skull surgery in infancy-a potential source of worry for parents when their treated children begin involvement in sports. METHODS: Electronic multiple choice survey of parents of children who had undergone craniosynostosis surgery in infancy using 5-point Likert scales. RESULTS: Fifty-nine completed surveys were obtained from parents of children who had undergone previous craniosynostosis surgery. Mean age of children was 7.8 years (range 3 months to 22 years), with 36 non-syndromic and 23 syndromic cases. The most common surgery was fronto-orbital remodelling (18). Fifty-two of 59 were involved in athletic activity. The most intense sport type was non-contact in 23, light contact in 20, heavy contact in 4 and combat in 5. Participation level was school mandatory in 12, school club in 17, non-school sport club in 21 and regional representative in 2. One child had been advised to avoid sport by an external physician. Mean anxiety (1-5 Likert) increased with sport intensity: non-contact 1.7, light contact 2.2, heavy contact 3.5 and combat 3.6. Twenty-nine of 59 parents had been given specific advice by the Craniofacial Team regarding athletic activity, 28 of which found useful. Three sport-related head injuries were reported, none of which required hospitalisation. CONCLUSION: Little information exists regarding sports for children after craniosynostosis surgery. This study suggests that parental anxiety remains high, particularly for high impact/combat sports, and that parents would like more information from clinicians about the safety of post-operative sporting activities.

Spring-assisted posterior vault expansion-a single-centre experience of 200 cases.

PURPOSE: Children affected by premature fusion of the cranial sutures due to craniosynostosis can present with raised intracranial pressure and (turri)brachycephalic head shapes that require surgical treatment. Spring-assisted posterior vault expansion (SA-PVE) is the surgical technique of choice at Great Ormond Street Hospital for Children (GOSH), London, UK. This study aims to report the SA-PVE clinical experience of GOSH to date. METHODS: A retrospective review was carried out including all SA-PVE cases performed at GOSH between 2008 and 2020. Demographic and clinical data were recorded including genetic diagnosis, craniofacial surgical history, surgical indication and assessment, age at time of surgery (spring insertion and removal), operative time, in-patient stay, blood transfusion requirements, additional/secondary (cranio)facial procedures, and complications. RESULTS: Between 2008 and 2020, 200 SA-PVEs were undertaken in 184 patients (61% male). The study population consisted of patients affected by syndromic (65%) and non-syndromic disorders. Concerns regarding raised intracranial pressure were the surgical driver in 75% of the cases, with the remainder operated for shape correction. Median age for SA-PVE was 19 months (range, 2-131). Average operative time for first SA-PVE was 150 min and 87 for spring removal. Median in-patient stay was 3 nights, and 88 patients received a mean of 204.4 ml of blood transfusion at time of spring insertion. A single SA-PVE sufficed in 156 patients (85%) to date (26 springs still in situ at time of this analysis); 16 patients underwent repeat SA-PVE, whilst 12 underwent rigid redo. A second SA-PVE was needed in significantly more cases when the first SA-PVE was performed before age 1 year. Complications occurred in 26 patients with a total of 32 events, including one death. Forty-one patients underwent fronto-orbital remodelling at spring removal and 22 required additional cranio(maxillo)facial procedures. CONCLUSIONS: Spring-assisted posterior vault expansion is a safe, efficient, and effective procedure based on our 12-year experience. Those that are treated early in life might require a repeat SA-PVE. Long-term follow-up is recommended as some would require additional craniomaxillofacial correction later in life.

Maxillary Changes Following Facial Bipartition - A Three-Dimensional Quantification.

INTRODUCTION: Children with Apert syndrome have hypertelorism and midfacial hypoplasia, which can be treated with facial bipartition (FB), often aided by rigid external distraction. The technique involves a midline osteotomy that lateralizes the maxillary segments, resulting in posterior cross-bites and midline diastema. Varying degrees of spontaneous realignment of the dental arches occurs postoperatively. This study aims to quantify these movements and assess whether they occur as part of a wider skeletal relapse or as dental compensation. METHODS: Patients who underwent FB and had high quality computed tomography scans at the preoperative stage, immediately postsurgery, and later postoperatively were reviewed. DICOM files were converted to three-dimensional bone meshes and anatomical point-to-point displacements were quantified using nonrigid iterative closest point registration. Displacements were visualized using arrow maps, thereby providing an overview of the movements of the facial skeleton and dentition. RESULTS: Five patients with Apert syndrome were included. In all cases, the arrow maps demonstrated initial significant anterior movement of the frontofacial segment coupled with medial rotation of the orbits and transverse divergence of the maxillary arches. The bony position following initial surgery was shown to be largely stable, with primary dentoalveolar relapse correcting the dental alignment. CONCLUSIONS: This study showed that spontaneous dental compensation occurs following FB without compromising the surgical result. It may be appropriate to delay active orthodontic for 6-months postoperatively until completion of this early compensatory phase.

Local Soft Tissue and Bone Displacements Following Midfacial Bipartition Distraction in Apert Syndrome - Quantification Using a Semi-Automated Method.

ABSTRACT: Patients with Apert syndrome experience midfacial hypoplasia, hypertelorism, and downslanting palpebral fissures which can be corrected by midfacial bipartition distraction with rigid external distraction device. Quantitative studies typically focus on quantifying rigid advancement and rotation postdistraction, but intrinsic shape changes of bone and soft tissue remain unknown. This study presents a method to quantify these changes. Pre- and post-operative computed tomography scans from patients with Apert syndrome undergoing midfacial bipartition distraction with rigid external distraction device were collected. Digital Imaging and Communications in Medicine files were converted to three-dimensional bone and soft tissue reconstructions. Postoperative reconstructions were aligned on the preoperative maxilla, followed by nonrigid iterative closest point transformation to determine local shape changes. Anatomical point-to-point displacements were calculated and visualized using a heatmap and arrow map. Nine patients were included.Zygomatic arches and frontal bone demonstrated the largest changes. Mid-lateral to supra-orbital rim showed an upward, inward motion. Mean bone displacements ranged from 3.3 to 12.8 mm. Soft tissue displacements were relatively smaller, with greatest changes at the lateral canthi. Midfacial bipartition distraction with rigid external distraction device results in upward, inward rotation of the orbits, upward rotation of the zygomatic arch, and relative posterior motion of the frontal bone. Local movements were successfully quantified using a novel method, which can be applied to other surgical techniques/syndromes.

Lack of association of cranial lacunae with intracranial hypertension in children with Crouzon syndrome and Apert syndrome: a 3D morphometric quantitative analysis.

PURPOSE: Cranial lacunae (foci of attenuated calvarial bone) are CT equivalents of "copper beating" seen on plain skull radiographs in children with craniosynostosis. The qualitative presence of copper beating has not been found to be useful for the diagnosis of intracranial hypertension (IH) in these patients. 3D morphometric analysis (3DMA) allows a more systematic and quantitative assessment of calvarial attenuation. We used 3DMA to examine the relationship between cranial lacunae and IH in children with Crouzon and Apert syndromic craniosynostosis. METHODS: Patients were divided into IH and non-IH groups defined on an intention-to-treat basis. Pre-operative CT scans were converted into 3D skull models and processed to quantify lacunae as a percentage of calvarium surface area (LCP). This was done on individual bone and whole skull basis. RESULTS: Eighteen consecutive children with Crouzon's syndrome and 17 with Apert syndrome were identified. Median age at CT scan was 135 days (range 6-1778). Of the 35 children, 21 required surgery for IH at median age of 364 days (range 38-1710). Of these 21 children, 14 had lacunae with mean LCP of 3% (0-28%). Of the 14 non-IH children, 8 had lacunae with mean LCP of 2% (0-8%). LCP was not significantly different between IH and non-IH groups. Parietal bones were most likely to show lacunae (IH 14/21, non-IH 9/14), followed by occipital (IH 8/21, non-IH 3/14), and frontal (IH 6/21, non-IH 2/14). CONCLUSION: Results suggest that cranial lacunae, measured using quantitative 3DMA, do not correlate with IH, in agreement with evidence from qualitative plain skull radiograph studies.

A Novel Medial Canthal Reconstruction Technique in Children With Blepharophimosis Syndrome.

PURPOSE: There are different techniques for medial canthoplasty in blepharophimosis syndrome where individuals have epicanthus inversus and telecanthus leading to typical facial appearances. These methods have potential problems with scarring, epistaxis, and extrusion of metal plates. METHODS: The authors describe a novel technique of medial canthal reconstruction using titanium microplates with microscrew fixation to the anterior lacrimal crest, with effective, safe, and reproducible results. RESULTS: Seven children with blepharophimosis syndrome underwent medial canthus reconstruction surgery at a single center with the collaboration of a pediatric oculoplastic surgeon and craniofacial plastic surgeon to improve eye opening through correction of the lid contours and telecanthus. CONCLUSIONS: This is a safe, effective, and reproducible technique, with minimal morbidity and rapid postoperative recovery in children. It produces cosmetically acceptable scars and a strong stable reconstruction of the medial canthal insertion.

Developing an In-house Interdisciplinary Three-Dimensional Service: Challenges, Benefits, and Innovative Health Care Solutions.

Three-dimensional printing (3DP) technologies have been employed in regular medical specialties. They span wide scope of uses, from creating 3D medical models to design and manufacture of Patient-specific implants and guidance devices which help to optimize medical treatments, patient education, and medical training. This article aims to provide an in-depth analysis of factors and aspects to consider when planning to setup a 3D service within a hospital serving various medical specialties. It will also describe challenges that might affect 3D service development and sustainability and describe representative cases that highlight some of the innovative approaches that are possible with 3D technology. Several companies can offer such 3DP service. They are often web based, time consuming, and requiring special call conference arrangements. Conversely, the establishment of in-house specialized hospital-based 3D services reduces the risks to personal information, while facilitating the development of local expertise in this technology. The establishment of a 3D facility requires careful consideration of multiple factors to enable the successful integration with existing services. These can be categorized under: planning, developing and sustaining 3D service; 3D service resources and networking workflow; resources and location; and 3D services quality and regulation management.

Perioperative Blood Loss and Transfusion in Craniosynostosis Surgery.

Craniosynostosis has an incidence of 1 in 2000 to 2500 live births and may be corrected through several methods including total calvarial remodeling and frontal orbital advancement remodeling. Blood loss during craniosynostosis surgery can be substantial, ranging from 20% to 500% of total circulating volume with a high associated risk of transfusion-related adverse events. The authors performed a retrospective analysis of all patients undergoing surgery for craniosynostosis at a tertiary pediatric craniofacial center with a focus on blood loss and subsequent transfusion.The authors reviewed 40 patients with craniosynostosis >16 years at a single-center. Data on perioperative blood loss and transfusion were obtained, including pre-, intra-, and postoperative hemoglobin, hematocrit, and use of tranexamic acid. The authors calculated estimated percentage of circulating red cell volume lost and transfused.The majority of patients had sagittal synostosis and underwent total calvarial remodeling (n = 20); the rest underwent frontal orbital advancement remodeling (n = 19) or lambdoid correction (n = 1). The average estimated volume red cell loss was 77% of circulating volume and 90% of patients received blood transfusion with an average 88.3% transfusion of circulating red cell volume. Longer operative time, younger age, and lower weight predisposed to >50% blood volume transfusion (P = 0.032, <0.005, <0.005 respectively).This single-center observational study reports red cell volume loss and volume of transfusion in children undergoing surgical correction of craniosynostosis. Red cell volume loss was comparative to that in the literature and in this cohort longer operative time, younger age, and lower weight predisposed to >50% blood volume transfusion.

Results Following Adoption of a Modified Melbourne Technique of Total Scaphocephaly Correction.

The Melbourne technique was described in 2008 as a novel method for complete correction of scaphocephaly. Since 2015, it has become our operation of choice for children with sagittal synostosis who are too old at presentation for minimally invasive techniques. Our modifications were 2-position (initially supine then prone) technique and undertaking a formal fronto-orbital remodeling to correct forehead contour. Retrospective chart review was used to record demographics, blood transfusion frequency and volumes, operating time, length of stay, clinical outcome, and complications. Eleven underwent modified Melbourne procedure between July 2015 and March 2017; 9 of 11 were male. All had a diagnosis of nonsyndromic sagittal synostosis. Mean age at surgery was 29 months. Mean surgical time was 6 hours. All patients required blood transfusion with a mean volume transfused of 29 mL/kg (range 13-83 mL/kg). For those 5 patients where preoperative and postoperative measurements were available, there was an increase in mean cephalic index (CI) from 0.64 to 0.75. All postoperative patients had a CI of over 0.70. Three-dimensional shape analysis indicated head shape change addressing all phenotypic aspects of scaphocephaly. In the 5 patients in which analysis could be undertaken, the mean intracranial volume increased from 1481 cm preoperatively to 1671 cm postoperatively, a mean increase in intracranial volume of 14%. The postoperative intracranial volume was higher than preoperative in all 5 patients. There were 4 minor and no major complications. Modified Melbourne procedure is safe and effective for the treatment of severe scaphocephaly in sagittal synostosis.

Anterior Fontanelle Wormian Bone With Exomphalos Major and Dysmorphic Facial Features: A Previously Unseen Association?

Wormian bones are independent ossification centers found within cranial sutures or fontanelles. Though common in adult populations, their presence in children can be associated with several conditions such as osteogenesis imperfecta, hypothyroidism, pyknodysostosis, cleidocranial dysostosis, rickets, and acrocallosal syndrome. These conditions encompass a large range of clinical features but there has only been 1 other reported patient of exomphalos occurring concurrently with these ossicles. The authors present the case of a child with an anterior fontanellar Wormian bone, dysmorphic facial features, and exomphalos major born to unaffected parents. The pattern of features seen in this child did not closely match any condition commonly associated with Wormian bones. The only other reported case of both Wormian bone and exomphalos was in a child with acrocallosal syndrome who presented with more severe dysmorphic features than seen here. It is possible that this patient represents a previously unknown association between acrocallosal syndrome and exomphalos or a less severe variant of the condition. Conversely, this patient may possibly illustrate a newly discovered association between Wormian bones, facial dysmorphism, and midline abdominal defects.

Hair Today; Scalped Tomorrow: Massive Subgaleal Haematoma Following Sudden Hair Pulling in an Adolescent in the Absence of Haematological Abnormality or Skull Fracture.

Subgaleal haematoma (SH) is a rare condition, most frequently observed in neonates as a complication of Ventouse-assisted delivery. There have been few patients reported beyond this period. Those that are present within the literature have typically resulted from significant blunt scalp trauma, with or without associated skull fracture. Those resulting secondary to relatively minor trauma, such as hair braiding or hair pulling, are rare but have been reported and are often associated with underlying haematological abnormalities or nonaccidental injury patients. Most patients resolve spontaneously and without complication. The authors report a rare patient of a delayed presentation of a massive SH in an adolescent following a seemingly innocuous episode of hair pulling whilst play-fighting, in the absence of any underlying haematological or anatomical abnormality. Due to the size of the SH and the appearance of large areas of calcification within the haematoma, early liaison with senior neuroradiologists and haematologists, to rule out underlying anatomical and haematological abnormalities, respectively, was essential to guide appropriate management. Our patient highlights the need for an awareness of the possible aetiologies of SH and the necessity of early active multidisciplinary team involvement in the management of such patients, which is critical to ensure optimum patient outcomes.

Assessing the Evidence for Nonobstetric Risk Factors for Deformational Plagiocephaly: Systematic Review and Meta-Analysis.

BACKGROUND: Plagiocephaly is defined as an asymmetrical distortion of the skull, resulting in an oblique trapezoid or parallelogram head shape. Deformational plagiocephaly (DP) is caused by forces acting on one side of the back of the head, distorting normal skull symmetry. OBJECTIVE: The aims of this systematic review and meta-analysis were to critically assess the evidence for nonobstetric risk factors for DP and to make evidence-based recommendations for reducing the prevalence of DP. METHODS: The selection criterion was studies reporting risk factors for DP. Case reviews, case series, expert opinions, and systematic reviews were excluded. PubMed and Web of Science were searched from August 21, 2010, to August 21, 2022. Publication bias was assessed using funnel plots. Meta-analyses were presented using forest plots. RESULTS: A total of 19 studies (cohort studies: n=13, 68%; case-control studies: n=5, 26%; and cross-sectional studies: n=1, 5%) with a total of 14,808 participants were included. Of the 43 investigated potential nonobstetric factors, 16 (37%) were associated with DP. Of these 16 factors, 12 (75%) had odds ratios (ORs) with 95% CIs not crossing 1: insufficient vitamin D intake (OR 7.15, 95% CI 3.77-13.54), head position preference (OR 4.75, 95% CI 3.36-6.73), bottle-only feeding (OR 4.65, 95% CI 2.70-8.00), reduced tummy time (OR 3.51, 95% CI 1.71-7.21), sleeping position (OR 3.12, 95% CI 2.21-4.39), fewer motor milestones reached by the age of 6 months (OR 2.56, 95% CI 1.66-3.96), obesity (OR 2.45, 95% CI 1.02-5.90), maternal education level (OR 1.66, 95% CI 1.17-2.37), male sex (OR 1.51, 95% CI 1.07-2.12), formula feeding (OR 1.51, 95% CI 1.00-2.27), head circumference (OR 1.22, 95% CI 1.06-1.40), and mechanical ventilation (OR 1.10, 95% CI 1.00-1.14). No evidence of publication bias was detected. CONCLUSIONS: This study provides a comprehensive assessment of the nonobstetric factors associated with DP and presents 11 evidence-based recommendations for reducing its prevalence. The primary limitation is that only publication bias was assessed. TRIAL REGISTRATION: PROSPERO CRD42020204979; https://www.crd.york.ac.uk/prospero/display_record.php? ID=CRD42020204979.

Using A Disentangled Neural Network to Objectively Assess the Outcomes of Midfacial Surgery in Syndromic Craniosynostosis.

BACKGROUND: Advancements in artificial intelligence and the development of shape models that quantify normal head shape and facial morphology provide frameworks by which the outcomes of craniofacial surgery can be compared. In this work, we will demonstrate the use of the Swap Disentangled Variational Autoencoder (SD-VAE) to objectively assess changes following midfacial surgery. MATERIALS AND METHODS: Our model is trained on a dataset of 1405 3D meshes of healthy and syndromic patients which was augmented using a technique based on spectral interpolation. Patients with a diagnosis of Apert and Crouzon syndrome who had undergone sub- or trans-cranial midfacial procedures utilising rigid external distraction were then interpreted using this model as the point of comparison. RESULTS: A total of 56 patients met our inclusion criteria, 20 with Apert and 36 with Crouzon syndrome. By using linear discriminant analysis to project the high-dimensional vectors derived by SD-VAE onto a 2D space, the shape properties of Apert and Crouzon syndrome can be visualised in relation to the healthy population. In this way, we are able to show how surgery elicits global shape changes in each patient. To assess the regional movements achieved during surgery, we use a novel metric derived from the Malahanobis distance to quantify movements through the latent space. CONCLUSION: Objective outcome evaluation, which encourages in-depth analysis and enhances decision making, is essential for the progression of surgical practice. We have demonstrated how artificial intelligence has the ability to improve our understanding of surgery and its effect on craniofacial morphology.

A computational modelling tool for prediction of head reshaping following endoscopic strip craniectomy and helmet therapy for the treatment of scaphocephaly.

BACKGROUND: Endoscopic strip craniectomy followed by helmet therapy (ESCH) is a minimally invasive approach for correcting sagittal craniosynostosis. The treatment involves a patient-specific helmet designed to facilitate lateral growth while constraining sagittal expansion. In this study, finite element modelling was used to predict post-treatment head reshaping, improving our comprehension of the necessary helmet therapy duration. METHOD: Six patients (aged 11 weeks to 9 months) who underwent ESCH at Connecticut Children's Hospital were enrolled in this study. Day-1 post-operative 3D scans were used to create skin, skull, and intracranial volume models. Patient-specific helmet models, incorporating areas for growth, were designed based on post-operative imaging. Brain growth was simulated through thermal expansion, and treatments were modelled according to post-operative Imaging available. Mechanical testing and finite element modelling were combined to determine patient-specific mechanical properties from bone samples collected from surgery. Validation compared simulated end-of-treatment skin surfaces with optical scans in terms of shape matching and cranial index estimation. RESULTS: Comparison between the simulated post-treatment head shape and optical scans showed that on average 97.3 ± 2.1 % of surface data points were within a distance range of -3 to 3 mm. The cranial index was also accurately predicted (r = 0.91). CONCLUSIONS: In conclusion, finite element models effectively predicted the ESCH cranial remodeling outcomes up to 8 months postoperatively. This computational tool offers valuable insights to guide and refine helmet treatment duration. This study also incorporated patient-specific material properties, enhancing the accuracy of the modeling approach.