Genetic determinism and hemispheric influence in hair whorl formation.

BACKGROUND: The mechanisms determining the laterality and the rotation direction of hair whorls are unknown. Here we report observations on twins investigating the genetic bases of whorl pattern formation. Knowing that vortex phenomena may depend on geographic effects, we also provide comparative data on whorls from children born in the Northern hemisphere (France) versus children born in the Southern hemisphere (Chile). MATERIAL AND METHODS: We retrospectively included children from three populations: (1) Northern hemisphere general population, (2) Southern hemisphere general population, and (3) same-sex Northern hemisphere twins. We recorded whorl rotation direction (clockwise, counterclockwise), whorl position (left, right, central) and twinning type. Univariate logistic models were used to screen for associations between rotation direction and whorl position. For twins, the variable of interest was binary, i.e. same rotation direction (reference class) or opposite directions for each twin pair. For controls, all single combinations were included as virtual twins, and compared to real twins. Odds ratios (OR) were compared for both hemispheres, for real twins and virtual (control) twins. RESULTS: Seventy-four (37 pairs) twins and 50 children from the general population of each hemisphere were included. The OR for opposite rotation directions between two twins was ≠1 (p = 0.017), meaning that whorls rotated preferentially in the same direction in twins. ORs were <1 for Northern and Southern hemispheres, meaning that whorls rotated preferentially in the same direction in simulated twins. OR for the Northern hemisphere (0.04 [0.03; 0.05]) was less than the OR for the Southern hemisphere (0.28 [0.24; 0.32]) with no confidence interval superimposition, indicating than counterclockwise whorls were more frequent in the Southern hemisphere (p < 0.001). CONCLUSIONS: We suggest that hair whorl formation is a genetically determined developmental process that can be influenced by extrinsic environmental factors. Our results furthermore underline the general importance of studies focused on limit phenomena that can provide insights on general developmental mechanisms. We plead for large-scale epidemiological assessments of hair whorls in several Northern and Southern hemisphere populations to confirm these surprising findings suggesting significant modulations of craniofacial development by geographic effects.

Mobility Assessment Using Multi-Positional MRI in Children with Cranio-Vertebral Junction Anomalies.

OBJECTIVE: This study aimed to assess the relevance of using multi-positional MRI (mMRI) to identify cranio-vertebral junction (CVJ) instability in pediatric patients with CVJ anomalies while determining objective mMRI criteria to detect this condition. MATERIAL AND METHODS: Data from children with CVJ anomalies who underwent a mMRI between 2017 and 2021 were retrospectively reviewed. Mobility assessment using mMRI involved: (1) morphometric analysis using hierarchical clustering on principal component analysis (HCPCA) to identify clusters of patients by considering their mobility similarities, assessed through delta (Δ) values of occipito-cervical parameters measured on mMRI; and (2) morphological analysis based on dynamic geometric CVJ models and analysis of displacement vectors between flexion and extension. Receiver operating characteristics (ROC) curves were generated for occipito-cervical parameters to establish instability cut-off values. (3) Additionally, an anatomical qualitative analysis of the CVJ was performed to identify morphological criteria of instability. RESULTS: Forty-seven patients with CVJ anomalies were included (26 females, 21 males; mean age: 10.2 years [3-18]). HCPCA identified 2 clusters: cluster №1 (stable patients, n = 39) and cluster №2 (unstable patients, n = 8). ΔpB-C2 (pB-C2 line delta) at ≥2.5 mm (AUC 0.98) and ΔBAI (Basion-axis Interval delta) ≥ 3 mm (AUC 0.97) predicted instability with 88% sensibility and 95% specificity and 88% sensitivity and 85% specificity, respectively. Geometric CVJ shape analysis differentiated patients along a continuum, from a low to a high CVJ motion that was characterized by a subluxation of C1 in the anterior direction. Qualitative analysis found correlations between instability and C2 anomalies, including fusions with C3 (body p = 0.032; posterior arch p = 0.045; inferior articular facets p = 0.012; lateral mass p = 0.029). CONCLUSIONS: We identified a cluster of pediatric patients with CVJ instability among a cohort of CVJ anomalies that were characterized by morphometric parameters with corresponding cut-off values that could serve as objective mMRI criteria. These findings warrant further validation through prospective case-control studies.

Facial dog bites in children: A public health problem highlighted by COVID-19 lockdown.

BACKGROUND: Stay-at-home injunction during COVID-19 pandemic led to new dynamics in households and increased the risk of domestic accidents involving pets. The aim of the study was to demonstrate an increase of facial dog bites in children during first lockdown period in France, compared to the same period in 2018 and 2019. Secondary objective was to investigate the demographics and circumstances in which dog bites occurred. METHODS: A retrospective multicentric study was conducted nationwide. Patients under 18 years old managed in fifteen oral and maxillofacial surgery departments for a dog bite were included. RESULTS: Eighty-seven patients were included. A significant increase of the number of children managed for facial dog bite was noticed in 2020 (p = 0.0005). The male-to-female ratio was significantly reversed in 2020 with more bites in girls than boys (p = 0.02). In 2020, children were mostly bitten to cheeks (28.6 %), lips-and-chin region (26.2 %), and eyelids (23.8 %). Severe bites increased in 2020, in comparison with 2018 and 2019. Dog bites occurring while petting or playing significantly increased in 2020 (31 %) (p = 0.03). CONCLUSION: The process leading to bites is highly dependent on the balance of dog-owner relationship. This was strongly disrupted during COVID-19 pandemic, resulting in the increase of dog bites in households. Regarding dog bites, face is the most vulnerable area in children. Its injury has lots of esthetic and functional consequences and maxillofacial surgeons have a key role to play in their prevention. Reminders of some of these management and prevention strategies are presented in this article.

Biallelic truncating variants in VGLL2 cause syngnathia in humans.

BACKGROUND: Syngnathia is an ultrarare craniofacial malformation characterised by an inability to open the mouth due to congenital fusion of the upper and lower jaws. The genetic causes of isolated bony syngnathia are unknown. METHODS: We used whole exome and Sanger sequencing and microsatellite analysis in six patients (from four families) presenting with syngnathia. We used CRISPR/Cas9 genome editing to generate vgll2a and vgll4l germline mutant zebrafish, and performed craniofacial cartilage analysis in homozygous mutants. RESULTS: We identified homozygous truncating variants in vestigial-like family member 2 (VGLL2) in all six patients. Two alleles were identified: one in families of Turkish origin and the other in families of Moroccan origin, suggesting a founder effect for each. A shared haplotype was confirmed for the Turkish patients. The VGLL family of genes encode cofactors of TEAD transcriptional regulators. Vgll2 is regionally expressed in the pharyngeal arches of model vertebrate embryos, and morpholino-based knockdown of vgll2a in zebrafish has been reported to cause defects in development of pharyngeal arch cartilages. However, we did not observe craniofacial anomalies in vgll2a or vgll4l homozygous mutant zebrafish nor in fish with double knockout of vgll2a and vgll4l. In Vgll2 -/- mice, which are known to present a skeletal muscle phenotype, we did not identify defects of the craniofacial skeleton. CONCLUSION: Our results suggest that although loss of VGLL2 leads to a striking jaw phenotype in humans, other vertebrates may have the capacity to compensate for its absence during craniofacial development.

Effects of distraction osteogenesis with Le Fort osteotomies on upper airway volumes: a systematic review and meta-analyses.

OBJECTIVE: Distraction osteogenesis is one of the treatment options in patients with severe maxillomandibular abnormalities to treat morphological and respiratory problems (obstructive sleep apnea syndrome). The study aimed to evaluate the effect of Le Fort I, II and III distraction osteogenesis (DO) on upper airway dimensions and respiratory function. METHODS: Electronic search was performed in PubMed, Scopus, Embase, Google Scholar and Cochrane databases. Studies that only involved two dimensional analyses were excluded. Besides, studies that performed DO in conjunction with orthognathic surgery were not considered. NIH quality assessment tool was used to evaluate the risk of bias. Meta-analyses were performed to assess sleep apnea indices and the mean differences in the airway dimensions before and after DO. Gradings of Recommendations, Assessment, Development and Evaluation were used to analyze the evidence level. RESULTS: Among the 114 studies that went under full-text analyses, 11 articles met the inclusion criteria. Results of the quantitative analyses showed that maxillary Le Fort III DO significantly increased the amounts of oropharyngeal, pharyngeal and upper airway volumes. However, apnea-hypopnea index (AHI) showed a non-significant improvement after this procedure. Besides, the dimensions of the airways increased with Le Fort I and II DO, according to a qualitative analysis. Considering the design of the included studies, our results had a low level of evidence. CONCLUSION: Maxillary Le Fort DO does not significantly impact AHI, while it significantly increases the airway dimensions. Meanwhile, multicentric studies with standardized evaluation are still required to confirm the effects of maxillary Le Fort DO on airway obstruction.

Craniofacial growth and function in achondroplasia: a multimodal 3D study on 15 patients.

BACKGROUND: Achondroplasia is the most frequent FGFR3-related chondrodysplasia, leading to rhizomelic dwarfism, craniofacial anomalies, stenosis of the foramen magnum, and sleep apnea. Craniofacial growth and its correlation with obstructive sleep apnea syndrome has not been assessed in achondroplasia. In this study, we provide a multimodal analysis of craniofacial growth and anatomo-functional correlations between craniofacial features and the severity of obstructive sleep apnea syndrome. METHODS: A multimodal study was performed based on a paediatric cohort of 15 achondroplasia patients (mean age, 7.8 ± 3.3 years), including clinical and sleep study data, 2D cephalometrics, and 3D geometric morphometry analyses, based on CT-scans (mean age at CT-scan: patients, 4.9 ± 4.9 years; controls, 3.7 ± 4.2 years). RESULTS: Craniofacial phenotype was characterized by maxillo-zygomatic retrusion, deep nasal root, and prominent forehead. 2D cephalometric studies showed constant maxillo-mandibular retrusion, with excessive vertical dimensions of the lower third of the face, and modifications of cranial base angles. All patients with available CT-scan had premature fusion of skull base synchondroses. 3D morphometric analyses showed more severe craniofacial phenotypes associated with increasing patient age, predominantly regarding the midface-with increased maxillary retrusion in older patients-and the skull base-with closure of the spheno-occipital angle. At the mandibular level, both the corpus and ramus showed shape modifications with age, with shortened anteroposterior mandibular length, as well as ramus and condylar region lengths. We report a significant correlation between the severity of maxillo-mandibular retrusion and obstructive sleep apnea syndrome (p < 0.01). CONCLUSIONS: Our study shows more severe craniofacial phenotypes at older ages, with increased maxillomandibular retrusion, and demonstrates a significant anatomo-functional correlation between the severity of midface and mandible craniofacial features and obstructive sleep apnea syndrome.

An automatic facial landmarking for children with rare diseases.

Two to three thousand syndromes modify facial features: their screening requires the eye of an expert in dysmorphology. A widely used tool in shape characterization is geometric morphometrics based on landmarks, which are precise and reproducible anatomical points. Landmark positioning is user dependent and time consuming. Many automatic landmarking tools are currently available but do not work for children, because they have mainly been trained using photographic databases of healthy adults. Here, we developed a method for building an automatic landmarking pipeline for frontal and lateral facial photographs as well as photographs of external ears. We evaluated the algorithm on patients diagnosed with Treacher Collins (TC) syndrome as it is the most frequent mandibulofacial dysostosis in humans and is clinically recognizable although highly variable in severity. We extracted photographs from the photographic database of the maxillofacial surgery and plastic surgery department of Hôpital Necker-Enfants Malades in Paris, France with the diagnosis of TC syndrome. The control group was built from children admitted for craniofacial trauma or skin lesions. After testing two methods of object detection by bounding boxes, a Haar Cascade-based tool and a Faster Region-based Convolutional Neural Network (Faster R-CNN)-based tool, we evaluated three different automatic annotation algorithms: the patch-based active appearance model (AAM), the holistic AAM, and the constrained local model (CLM). The final error corresponding to the distance between the points placed by automatic annotation and those placed by manual annotation was reported. We included, respectively, 1664, 2044, and 1375 manually annotated frontal, profile, and ear photographs. Object recognition was optimized with the Faster R-CNN-based detector. The best annotation model was the patch-based AAM (p < 0.001 for frontal faces, p = 0.082 for profile faces and p < 0.001 for ears). This automatic annotation model resulted in the same classification performance as manually annotated data. Pretraining on public photographs did not improve the performance of the model. We defined a pipeline to create automatic annotation models adapted to faces with congenital anomalies, an essential prerequisite for research in dysmorphology.

Parental and Child Diagnosis Storytelling and Self-Image in French Children With Cleft lip With or Without Cleft Palate.

OBJECTIVE: Psychosocial adjustment can be challenging for children with cleft lip with or without a cleft palate (CL ± P). Previous studies have linked social integration with self-acceptance and highlighted the impact of the parents' stress on self-acceptance. Teasing can be linked to children having difficulties explaining their diagnosis to others. This prospective research aimed to gain a better understanding of family communication about cleft, children's oral storytelling about their cleft, and explore their self-image and perceived familial acceptance. PARTICIPANTS: Parents and their children with CL ± P (N = 54; average age: 5.6 years). DESIGN: Semistructured interviews with parents and structured interviews with children were conducted regarding their oral storytelling focusing on scars from cleft lip surgery. Children completed a projective test to explore their self-image and perceptions of familial acceptance. Language screening was completed with the French Wechsler Preschool Primary Scale of Intelligence-Fourth Edition. RESULTS: Only 30% of children explained their cleft in a way appropriate for peers, including presence at birth, having had surgery, and scar location. Children's ability to explain their cleft was not related to language performance, which was in the average range of 84%. Children's cleft explanations were dependent on parents' narratives and education methods, including the use of verbal explanations and preoperative photographs. Children's storytelling was related to their self-image and perceived parental acceptance. CONCLUSION: Cleft teams should assist families in building their cleft story based on a complete explanation with photographs and a positive and accepting approach.

Injuries and child abuse increase during the pandemic over 12942 emergency admissions.

INTRODUCTION: A strict lockdown was decided from 17/03/2020 to 11/05/2020 in France in order to tackle the first wave of the COVID19 pandemic. In the Great Paris region, several areas are severely affected by overcrowding, creating difficult conditions for children and their families during a period of nearly two months. The objective was to assess the effects of the 2020 spring lockdown on injuries, child abuse and neglect. MATERIAL AND METHODS: The central medical data warehouse was screened for all pediatric admissions at emergency and critical care departments of 20 hospitals, in a cohort of 12942 children. Specific keywords were used to screen for both injuries and child abuse and neglect. RESULTS: We found head and neck trauma (1.2% in 2020 vs. 0.7% in 2019, p<0.001), burns (0.6% in 2020 vs. 0.1% in 2019, p < 0.001), lacerations (0.5% in 2020 vs. 0.3% in 2019, p<0.001), fractures (0.5% in 2020 vs. 0.3% in 2019, p<0.017), dog bites (0.1% in 2020 vs. 0.0% in 2019, p<0.001), and child abuse and neglect (18 cases during the 2020 lockdown vs. 24 cases in 2019, p=0.005) were significantly more prevalent during this period than during the same control period in 2019. CONCLUSIONS: These results indicate that specific prevention measures are crucial if strict lockdowns are to be decided in the future.

Intentional craniofacial remodelling in Europe in the XIXth century: Quantitative evidence of soft tissue modifications from Toulouse, France.

Intentional skull deformations have been practiced by every human population, from the prehistoric times until the XXth century. In Europe, they were specifically prevalent in the region of Toulouse, France. The soft-tissue modifications due to such practices are not well characterized in the literature due to the rarity of photographic data. Most studies on skull deformations are thus based on skeletal remains. Here we performed a controlled geometric morphometric assessment of 31 frontal pictures and 70 lateral pictures of individuals from Toulouse with intentional deformations extracted from two XIXth century historical French photographic archives. We also measured the forces exerted on the skull vault by the traditional deformation device from Toulouse using a 3D-printed skull and pressure sensors. We showed that individuals with Toulouse deformations have distinctive facial features, caused by moderate forces exerted on the skull vault. Our results exhibit and quantify for the first time the real face of intentional skull deformations, which are a ubiquitous and distinctive feature of the human species.

Quality versus emergency: How good were ventilation fittings produced by additive manufacturing to address shortages during the COVID19 pandemic?

OBJECTIVE: The coronavirus disease pandemic (COVID-19) increased the risk of shortage in intensive care devices, including fittings with intentional leaks. 3D-printing has been used worldwide to produce missing devices. Here we provide key elements towards better quality control of 3D-printed ventilation fittings in a context of sanitary crisis. MATERIAL AND METHODS: Five 3D-printed designs were assessed for non-intentional (junctional and parietal) and intentional leaks: 4 fittings 3D-printed in-house using FDeposition Modelling (FDM), 1 FDM 3D-printed fitting provided by an independent maker, and 2 fittings 3D-printed in-house using Polyjet technology. Five industrial models were included as controls. Two values of wall thickness and the use of coating were tested for in-house FDM-printed devices. RESULTS: Industrial and Polyjet-printed fittings had no parietal and junctional leaks, and satisfactory intentional leaks. In-house FDM-printed fittings had constant parietal leaks without coating, but this post-treatment method was efficient in controlling parietal sealing, even in devices with thinner walls (0.7 mm vs 2.3 mm). Nevertheless, the use of coating systematically induced absent or insufficient intentional leaks. Junctional leaks were constant with FDM-printed fittings but could be controlled using rubber junctions rather than usual rigid junctions. The properties of Polyjet-printed and FDM-printed fittings were stable over a period of 18 months. CONCLUSIONS: 3D-printing is a valid technology to produce ventilation devices but requires care in the choice of printing methods, raw materials, and post-treatment procedures. Even in a context of sanitary crisis, devices produced outside hospitals should be used only after professional quality control, with precise data available on printing protocols. The mechanical properties of ventilation devices are crucial for efficient ventilation, avoiding rebreathing of CO2, and preventing the dispersion of viral particles that can contaminate health professionals. Specific norms are still required to formalise quality control procedures for ventilation fittings, with the rise of 3D-printing initiatives and the perspective of new pandemics.

Growth charts in FGFR2- and FGFR3-related faciocraniosynostoses.

Objective: Faciocraniosynostoses (FCS) are malformations affecting the development of the bones of the skull and face, due to the premature closure of one or more craniofacial sutures, mostly secondary to activating Fibroblast Growth Factor Receptor (FGFR) 1-3 mutations. Gain-of-function FGFR3 mutations are also responsible for various conditions referred to as osteochondrodysplasia (OCD), characterized by structural and functional abnormalities of growth plate cartilages. We hypothesized that patients with FGFR-related faciocraniosynostoses may present extra-cranial growth anomalies. Study design: We retrospectively collected height and weight data from a cohort of 70 patients. Included patients were admitted for FGFR-related FCS between 2000 and 2021 at the Craniofacial Unit of Necker - Enfants Malades University Hospital in Paris, France. Results: We showed that FGFR-related faciocraniosynostoses had significantly reduced heights and weights relative to controls, and that two specific time periods (1-3 years and > 8 years of age) were associated with lower height and weight values. Four patients had received growth hormone treatment but remained below normal values for growth in height and weight. Conclusions: Patients with FGFR-related faciocraniosynostoses have clinically significant extra-cranial anomalies which are not currently investigated and managed in usual protocols; these patients could benefit from a systematic pre-pubertal endocrine assessment. More generally, our results extend the scope of extracranial anomalies in FGFR-related faciocraniosynostoses and support the hypothesis that all conditions with activating FGFR mutations affect both membranous ossification and long bones.

Ophthalmological findings in children with unicoronal craniosynostosis.

INTRODUCTION: Among non-syndromic, single-suture craniosynostoses, unicoronal craniosynostosis (UCS) presents the highest rate of ophthalmic manifestations requiring a visual follow-up, due to the high risk of amblyopia. After birth or during childhood, children with UCS have a high risk to present an aniso-astigmatism and a strabismus. The aim of this study was to characterize clinical ophthalmologic findings associated with UCS in a paediatric cohort. METHODS: This retrospective study included children admitted in our unit between 2015 and 2021, with isolated UCS treated in our institution and complete ophthalmological assessment comprising visual assessment, refractive status and oculomotor examination. Children with associated craniofacial disorders were excluded. RESULTS: A total of 28 children met the inclusion criteria. Median age was 62 [13-192] months with a large proportion of girls (86%) and 71% of right-sided UCS. The mean best corrected visual acuity was 0.07 (±0.13) LogMAR, including 10 (36%) children with an amblyopia or history of amblyopia. Astigmatism was significantly higher on the contralateral side of the UCS than on the ipsilateral side, with a refractive cylinder error of 0.97 (±1.06) vs 0.56 (±0.68) diopters, respectively (p = 0.03). Strabismus was observed in 20 patients (71%) with a main pattern of esotropia with a vertical component. A pseudo-superior oblique palsy was found in 13 children (65%) with a median cyclodeviation of 8.7° [-5,4°-20.6°]. CONCLUSION: Children with UCS experience a high rate of various visual manifestations. This study highlights their need for a strict ophthalmological follow-up, in order to early diagnose and prevent visual complications.

Scaphocephaly and increased intra-cranial pressure in non-operated adults: A controlled anthropological study on 21 skulls.

AIM AND SCOPE: The prevalence of increased intra-cranial pressure (ICP) in patients with scaphocephaly is controversial. Here, based on anthropological material, we aimed to determine whether adults with non-operated sagittal synostosis show indirect signs of increased ICP. MATERIALS AND METHODS: Thirty-eight dry skulls (21 skulls with sagittal craniosynostosis and 17 controls) were selected from the collections of the National Museum of Natural History (Paris, France). All skulls registered as 'fused sagittal suture' or 'scaphocephaly' in the registry of the Museum were included. All had total fusion of the sagittal suture. Controls were selected within skulls of similar origin (France), without visible craniofacial anomalies. The 38 skulls were CT-scanned using a standard medical CT-scan with a protocol dedicated to dry bone imaging. Eight radiological signs associated with raised ICP were assessed: (1) calvaria and (2) skull base thinning, (3) dorsum sellae erosion, (4) sella turcica lengthening, (5) copper beaten skull, (6) suture diastasis, (7) persistent metopic suture, and (8) small frontal sinus. Scaphocephaly was assessed based on head circumference, cranial index, intra-cranial volume, fronto-nasal angle, and inter-zygomatic distance. Linear and non-linear logistic models were used to compare groups. RESULTS: 19/21 skulls with sagittal synostosis were significantly scaphocephalic. None of the criteria for ICP were significantly different in skulls with scaphocephaly relative to controls. Nevertheless, 5 individual skulls with scaphocephaly had ≥ 3 signs in favor of a history of raised ICP. We do not report the significant prevalence of indirect signs of raised ICP in adults with scaphocephaly. These results do not allow ruling out a history of early raised ICP or of minor prolonged raised ICP. Even though our findings support the fact that scaphocephaly is not significantly associated with prolonged raised ICP, individual cases (5/21) with clear signs in favor of a history of brain compression indicate that scaphocephaly correction should be considered as a functional procedure until the production of clear evidence. Cognitive assessments of non-operated adult patients with scaphocephaly could contribute to tackle this recurring question in craniofacial surgery.

Paediatric skull growth models: A systematic review of applications to normal skulls and craniosynostoses.

INTRODUCTION: Craniosynostoses affect 1/2000 births and their incidence is currently increasing. Without surgery, craniosynostosis can lead to neurological issues due to restrained brain growth and social stigma due to abnormal head shapes. Understanding growth patterns is essential to develop surgical planning approaches and predict short- and long-term post-operative results. Here we provide a systematic review of normal and pathological cranial vault growth models. MATERIAL AND METHODS: The systematic review of the literature identified descriptive and comprehensive skull growth models with the following criteria: full text articles dedicated to the skull vault of children under 2 years of age, without focus on molecular and cellular mechanisms. Models were analysed based on initial geometry, numerical method, age determination method and validation process. RESULTS: A total of 14 articles including 17 models was reviewed. Four descriptive models were assessed, including 3 models using statistical analyses and 1 based on deformational methods. Thirteen comprehensive models were assessed including 7 finite element models and 6 diffusion models. Results from the current literature showed that successful models combined analyses of cranial vault shape and suture bone formation. DISCUSSION: Growth modelling is central when assessing craniofacial architecture in young patients and will be a key factor in the development of future customized treatment strategies. Recurrent technical difficulties were encountered by most authors when generalizing a specific craniosynostosis model to all types of craniosynostoses, when assessing the role of the brain and when attempting to relate the age with different stages of growth.

Dental phenotype in Crouzon syndrome: A controlled radiographic study in 22 patients.

OBJECTIVE: This retrospective radiographic controlled study investigates the dental phenotype in patients with Crouzon syndrome to determine if differences are observed as suggested by the FGFR2C342Y/+ Crouzon mouse models, and whether these models could be of interest to study the role of this mutation in tooth development. DESIGN: We assessed dental phenotype using dedicated linear measurements in 22 children with Crouzon syndrome and compared tooth morphology in both primary and permanent dentitions to an age-matched control group. Descriptive statistics were performed with "Sex" and "Age" as covariates for the permanent tooth models and "Sex" only for the primary tooth models, to take into account potential confounding factors. RESULTS: We showed that permanent but not primary tooth dimensions were globally reduced in Crouzon syndrome, without microdontia. In permanent dentition, crown height, mesiodistal and faciolingual cervical diameters were reduced by 6.3%, 5.7% and 5.5% respectively (p < 0.05). CONCLUSION: Our results underline the implication of Fibroblast Growth Factor Receptor 2 (FGFR2) in dental development of humans and contribute to support FGFR2C342Y/+ Crouzon mouse models as partial replicas of this condition, including in the oral region.

In-house 3D printing: Why, when, and how? Overview of the national French good practice guidelines for in-house 3D-printing in maxillo-facial surgery, stomatology, and oral surgery.

3D-printing is part of the daily practice of maxillo-facial surgeons, stomatologists and oral surgeons. To date, no French health center is producing in-house medical devices according to the new European standards. Based on all the evidence-based data available, a group of experts from the French Society of Stomatology, Maxillo-Facial Surgery and Oral Surgery (Société Française de Chirurgie Maxillofaciale, Stomatologie et Chirurgie Orale, SFSCMFCO), provide good practice guidelines for in-house 3D-printing in maxillo-facial surgery, stomatology, and oral surgery. Briefly, technical considerations related to printers and CAD software, which were the main challenges in the last ten years, are now nearly trivial questions. The central current issues when planning the implementation of an in-house 3D-printing platform are economic and regulatory. Successful in-house 3D platforms rely on close collaborations between health professionals and engineers, backed by regulatory and logistic specialists. Several large-scale academic projects across France will soon provide definitive answers to governance and economical questions related to the use of in-house 3D printing.

Craniosynostosis: Monobloc Distraction with Internal Device and Its Variant for Infants with Severe Syndromic Craniosynostosis.

The introduction of distraction osteogenesis to frontofacial monobloc advancement has increased the safety of the procedure. One hundred forty-seven patients with syndromic craniosynostosis underwent frontofacial monobloc advancement using 4 internal distractors. Twenty-five were aged 18 months or less. Ten patients presented with a tracheostomy, 5 (50%) were decannulated after surgery, and 3 others (30%) required an additional intervention before decannulation. Six patients required the addition of a transfacial pin and external traction. Very early frontofacial monobloc with 4 internal distractors is a safe and effective treatment to protect the ophthalmic, neurologic, and respiratory functions in infants with severe syndromic craniosynostosis.

A Case of Complex Facial Reconstruction Illuminates Paul Tessier's Surgical State of Mind.

ABSTRACT: Successful head and neck reconstructions tackle both morphological and functional issues within treatment plans involving multiple coordinated steps. Nowadays, biomaterials, computer-assisted surgery, and free tissue transfers have greatly increased the potentialities of craniofacial surgeons. In the 1970s, when Paul Tessier, one of the founders of modern plastic surgery, was at the peak of his career, complex reconstructions had little technology to rely on. Here we report a case of facial reconstruction after gunshot trauma performed by Paul Tessier based on his "craniofacial autarchy" principle, that is using solely local flaps and grafts harvested in the head and neck area. This case involved 30 procedures on the mandible, maxilla, chin, lips, and nose. Based on data from the archives from the "Association Française des Chirurgiens de la Face" (Amiens, France) we provide details on Tessier's approach to surgical planning and on his global conception of treatment plans in reconstructive surgery.