Mixed reality guided advancement osteotomies in congenital craniofacial malformations.

This paper describes our experience with mixed reality (MR) intra-operative guides in patients with congenital craniofacial malformations. The first case was a patient with bilateral hemifacial microsomia. He underwent bilateral mandibular distraction osteogenesis. Pre-operative virtual planning determined the sites of osteotomy. Standard Tessellation Language (STL) files of mandibular 3D models with osteotomy sites were uploaded onto the HoloLens 2® MR glasses (Microsoft®, Washington, USA). The superimposed hologram denoted the osteotomy line. This was validated with a physical cutting guide. The second case was a patient with Crouzon's syndrome. A modified Lefort 2 advancement was performed to correct his midfacial deficiency. Pre-operative virtual planning was performed to determine the sites of osteotomies. Superimposed hologram using the Hololens 2® denoted the osteotomy sites. These were validated with a conventional intra-operative navigation system. The advantages of using MR include its immediate availability for use; saving time and costs. MR allows surgeons to maintain continuous line-of-sight within the operative field. A robust registration system is required to anchor the hologram onto the patient's skull without variations in hologram position from different angles of gaze. MR has the potential to function as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation. LAY SUMMARY: We describe the use of mixed reality intra-operative guides in patients with congenital craniofacial malformations. Our experience shows the potential MR has as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation.

Ocular manifestations and treatment progress of Crouzon syndrome.

PURPOSE: Crouzon syndrome is a congenital genetic disease caused by mutations of the FGFR2 gene on chromosome 10. It is usually inherited in an autosomal dominant pattern and is one of the most common types of craniosynostosis syndromes. This article focuses on the ophthalmology-related aspects of Crouzon syndrome in order to help diagnose and develop personalized treatment plans. METHODS: A combined systematic search of PubMed electronic database by using Boolean operators AND and OR was conducted, choosing the following keywords: "Crouzon", "craniosynostosis", " eye ", " oculus ", " ocular ", " ophthalmic ", " ophthalmologic ", " ophthalmology ", " globe ", " orbit ", " exophthalmos ", " exorbitism ", " keratopathy ", " visual " etc. After the initial screening of these articles, repetitive literatures were excluded. RESULTS: 47 articles were selected. This article introduces the ocular manifestations, possible pathogenesis and treatment progress in Crouzon syndrome. CONCLUSIONS: The incidence of ocular abnormalities in Crouzon syndrome is very high, such as shallow orbits, exophthalmos, hypertelorism, exposure keratopathy, strabismus, optic neuropathy, ametropia, glaucoma, etc. The pathogenesis of these ocular abnormalities is related to orbital deformities. Most of the treatments are aimed at compensating the abnormal anatomic structure at present.

[Optic canal stenosis in Crouzon syndrome: a case report and literature review]. / Stenoz zritel'nykh kanalov pri sindrome Kruzona: klinicheskii sluchai i obzor literatury.

BACKGROUND: Incidence of Crouzon syndrome is 1 per 25.000-31.000 newborns. This syndrome is extremely rarely accompanied by optic canal stenosis. OBJECTIVE: To present a patient with Crouzon syndrome and optic canal stenosis, to discuss the management of such patients considering own and literature data. MATERIAL AND METHODS: A 6-year-old boy presented with Crouzon syndrome (verified by molecular genetic research, i.e. FGFR2 gene mutation). The patient underwent 3 surgeries for craniosynostosis and hydrocephalus. Nevertheless, visual acuity progressively decreased despite patent ventriculoperitoneal shunt. Examination revealed severe decrease in visual functions with optic disc congestion under secondary atrophy. MRI data on subarachnoid CSF accumulation over both optic nerves potentially indicated optic canal stenosis. This assumption was confirmed by 3D CT. RESULTS: The patient underwent decompression of both optic canals with subsequent improvement of visual functions. CONCLUSION: Vision decrease following Crouzon syndrome may be due to optic canal stenosis. Decompression may be effective, even in long-term course of disease, and improve visual functions.

Cranial bone microarchitecture in a mouse model for syndromic craniosynostosis.

Crouzon syndrome is a congenital craniofacial disorder caused by mutations in the Fibroblast Growth Factor Receptor 2 (FGFR2). It is characterized by the premature fusion of cranial sutures, leading to a brachycephalic head shape, and midfacial hypoplasia. The aim of this study was to investigate the effect of the FGFR2 mutation on the microarchitecture of cranial bones at different stages of postnatal skull development, using the FGFR2C342Y mouse model. Apart from craniosynostosis, this model shows cranial bone abnormalities. High-resolution synchrotron microtomography images of the frontal and parietal bone were acquired for both FGFR2C342Y/+ (Crouzon, heterozygous mutant) and FGFR2+/+ (control, wild-type) mice at five ages (postnatal days 1, 3, 7, 14 and 21, n = 6 each). Morphometric measurements were determined for cortical bone porosity: osteocyte lacunae and canals. General linear model to assess the effect of age, anatomical location and genotype was carried out for each morphometric measurement. Histological analysis was performed to validate the findings. In both groups (Crouzon and wild-type), statistical difference in bone volume fraction, average canal volume, lacunar number density, lacunar volume density and canal volume density was found at most age points, with the frontal bone generally showing higher porosity and fewer lacunae. Frontal bone showed differences between the Crouzon and wild-type groups in terms of lacunar morphometry (average lacunar volume, lacunar number density and lacunar volume density) with larger, less dense lacunae around the postnatal age of P7-P14. Histological analysis of bone showed marked differences in frontal bone only. These findings provide a better understanding of the pathogenesis of Crouzon syndrome and will contribute to computational models that predict postoperative changes with the aim to improve surgical outcome.

New CRISPR/Cas9-based Fgfr2C361Y/+ mouse model of Crouzon syndrome exhibits skull and behavioral abnormalities.

Crouzon syndrome (CS), a syndromic craniosynostosis, is a craniofacial developmental deformity caused by mutations in fibroblast growth factor receptor 2 (FGFR2). Previous CS mouse models constructed using traditional gene editing techniques faced issues such as low targeting efficiency, extended lineage cycles, and inconsistent and unstable phenotypes. In this study, a CRISPR/Cas9-mediated strategy was employed to induce a functional augmentation of the Fgfr2 point mutation in mice. Various techniques, including bone staining, micro-CT, histological methods, and behavioral experiments, were employed to systematically examine and corroborate phenotypic disparities between mutant mice (Fgfr2C361Y/+) and their wild-type littermates. Confirmed via PCR-Sanger sequencing, we successfully induced the p.Cys361Tyr missense mutation in the Fgfr2 IIIc isoform of the extracellular domain (corresponding to the p.Cys342Tyr mutation in humans) based on Fgfr2-215 transcript (ENSMUST00000122054.8). Fgfr2C361Y/+ mice exhibited characteristics consistent with the phenotypic features associated with CS, including skull-vault craniosynostosis, skull deformity, shallow orbits accompanied by exophthalmos, midface hypoplasia with malocclusion, and shortened skull base, notably without any apparent limb defects. Furthermore, mutant mice displayed behavioral abnormalities encompassing deficits in learning and memory, social interaction, and motor dysfunction, without anxiety-related disorders. Histopathological examination of the hippocampal region revealed structural abnormalities, suggesting possible brain development impairment secondary to craniosynostosis. In conclusion, we constructed a novel gene-edited Fgfr2C361Y/+ mice strain based on CRISPR/Cas9, which displayed skull and behavioral abnormalities, serving as a new model for studying genetic molecular mechanisms and exploring treatments for CS. KEY MESSAGES: CRISPR/Cas9 crafted a Crouzon model by enhancing Fgfr2-C361Y in mice. Fgfr2C361Y/+ mice replicate CS phenotypes-craniosynostosis and midface anomalies. Mutant mice show diverse behavioral abnormalities, impacting learning and memory. Fgfr2C361Y/+ mice offer a novel model for cranial suture studies and therapeutic exploration.

Radiological Diagnosis of Crouzon Syndrome: A Case Study.

Crouzon syndrome, distinguished by a classic trio of an atypical skull structure, distinctive facial features, and protruding eyes, ranks among the most prevalent types of craniofacial dysostosis. Therefore, patients presenting with dental abnormalities are under-reported in medical literature despite the developmental neurological defects. We report a rare case of Crouzon syndrome in a four-year-old girl who had forward displacement of the lower jaw, bulging eyes, undeveloped upper jaw, and dental abnormalities. She was evaluated with cranial computed tomography with three-dimensional reconstruction; genetic studies confirmed the findings.

Unexpected massive bleeding during the modified LeFort III advancement surgery for Crouzon syndrome: A case report.

Key Clinical Message: Vigilant monitoring for postoperative complications, including bleeding and dysrhythmia, is crucial in patients with craniosynostosis syndromes like Crouzon syndrome undergoing craniofacial surgery, with a thorough evaluation, including coagulation tests, assisting in diagnosing underlying conditions such as von Willebrand disease subtype 1 to inform appropriate management strategies. Abstract: Crouzon syndrome is a rare genetic disorder affecting craniofacial structures. Its etiology is the premature fusion of cranial sutures. The LeFort III advancement surgery is a commonly used approach to correct malformations related to midface hypoplasia. Complications following surgical treatment of craniosynostosis and craniofacial syndromes can include both intracranial and extracranial problems. Reporting of this syndrome and the surgery complications, in addition to consideration of other differential diagnoses, can help improve the treatment plan and surgery outcomes. The aim of the article is to report a 14-year-old female with Crouzon syndrome who underwent the modified LeFort III osteotomy and developed unexpected massive bleeding during the surgery. Post-surgery, she experienced complications including dysrhythmia, hypothermia, and cyanosis. Treatment included fluid therapy, blood transfusions, and antibiotic therapy for suspected septic shock. Differential diagnosis was disseminated intravascular coagulation but was ruled out. Post-discharge, coagulation tests suggested von Willebrand disease subtype 1 as the diagnosis. Excessive bleeding during surgery for craniosynostosis syndromes is a significant and concerning issue in the surgical management of Crouzon syndrome. For patients with von Willebrand disease who are candidates for elective surgeries, von Willebrand factor concentrates or recombinant von Willebrand factor can be used.

An Adult Case of Crouzon Syndrome: Diagnostic Features and Treatment Modalities.

Craniosynostosis syndromes are birth defects characterized by the premature fusion of one or more cranial sutures before the completion of brain growth and development. Crouzon syndrome (CS) is the most common craniosynostosis condition. The CS manifestations result from the early fusion of superior and posterior sutures of the maxilla along the orbital wall and affect the cranial vault, base, orbital, and maxillary regions. This report presents a rare case of a 25-year-old male CS patient referred for orthodontic treatment with the chief complaint of severe irregularities in the arrangement of teeth and abnormal facial appearance. In this report, the clinical, cephalometric features, and initial orthodontic management of this patient are discussed as part of multidisciplinary management.

Three-dimensional quantification of soft tissue changes and its relationship to skeletal changes after Le Fort III, monobloc, and facial bipartition in syndromic craniosynostosis.

To determine the effect of midface surgery on soft tissue changes and their relationship to hard tissue changes in patients with syndromic craniosynostosis. A retrospective analysis of patients who had undergone Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB) was conducted. A 3D soft tissue mesh was generated from the preoperative scan and registered to the postoperative scan, after which the advancement was visualised. A total of 68 patients were included: 28 had undergone LFIII, 27 MB, and 13 FB. The included diagnoses were Apert (n = 23), Crouzon (n = 34), and craniofrontonasal syndrome (n = 11). After LFIII, most soft tissue advancement was seen around subnasale and pronasale (mean 15.1 ± 5.9 mm and 14.7 ± 5.7 mm, at age 7-12 years). After MB, a greater hard tissue than soft tissue advancement was seen for most landmarks, showing a high positive correlation. In patients undergoing FB without distraction (n = 10), mean preoperative inter-canthal distance was 48.9 mm, this reduced by 6.9 mm postoperatively. This study provides a comprehensive overview of the outcomes after midface surgery using 3D quantification for a better understanding of the soft tissue changes and their relationship to hard tissue changes.

Skeletal changes after midface surgery in patients with craniofacial deformities: a three-dimensional quantification method.

To determine the skeletal changes after midface surgery in patients with syndromic craniosynostosis who underwent Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB). This was a retrospective study including 75 patients: 33 treated by LFIII, 29 by MB, and 13 by FB. Twenty-five had a diagnosis of Apert, 39 Crouzon, and 11 craniofrontonasal syndrome. A three-dimensional mesh was created from the preoperative scan and registered to the postoperative scan to visualise the advancement. LFIII at age 7-12 years effectuated a higher mean advancement in the maxillary (15.5 mm) and zygomatic (7.6 mm) regions when compared to ≥13 years (10.2 mm and 5.5 mm). After MB, mean advancement of the fronto-orbital region was higher at <7 years (16.4 mm), and similarly lower at ages 7-12 (13.8 mm) and ≥13 (12.5 mm). The mean preoperative inter-dacryon distance (34.4 ± 4.4 mm) was reduced by 8.7 ± 4.2 mm after FB without distraction (n = 10). More advancement was seen when midface surgery was performed at a younger age, due to more severe cases and a desire for overcorrection. The highest mean advancement was observed in the fronto-orbital region. Antero-inferior rotational movement was seen after all three techniques.

Alterations in Sphenoid Anatomy in Craniosynostosis: Implications for Fronto-Orbital Advancement.

OBJECTIVE: Fronto-orbital advancement involves removal of the fronto-orbital bandeau. Visualization of the saw blade is lost as it passes through the fronto-orbital-sphenoid junction (FOSJ), placing the temporal lobe at risk of injury. We aim to provide a 3D analysis of the space surrounding this osteotomy to differentiate various types of craniosynostoses. DESIGN: Retrospective cohort. SETTING: Institutional. PATIENTS: Thirty patients with isolated unicoronal synostosis, nonsyndromic bicoronal synostosis, metopic synostosis, Apert syndrome, Crouzon syndrome, and Muenke syndrome. INTERVENTIONS: CT scans conducted between 2 months to 2 years of age were 3D reconstructed to compare craniometrics against normal controls. MAIN OUTCOME MEASURE(S): Craniometrics. RESULTS: The mean bone thickness of the FOSJ at the level of the supraorbital rim was significantly small for the Apert, unicoronal and bicoronal groups. The mean vertical height of the middle cranial fossa from the lesser sphenoid wing was significantly greater in the unicoronal group. The mean vertical height of the tip of the temporal lobe from the lateral sphenoid ridge was greater in the unicoronal, isolated bicoronal, and Apert groups. The mean corneal protrusion beyond the lateral orbital rim was significantly greater in the Apert and unicoronal groups. The mean horizontal depth of the orbit was smallest in the Apert group. The mean vertical distance between the dacryon and the foramen cecum, and the mean volume of temporal lobe beneath the sphenoid shelf were the largest in the Apert group. CONCLUSIONS: Patients with Apert syndrome have the most unfavorable morphology of the anterior and middle cranial fossae.

Correlation analysis of airway-facial phenotype in Crouzon syndrome by geometric morphometrics: A promising method for non-radiation airway evaluation.

AIM: This study aimed to verify the correlation of the airway-facial phenotype and visualize the morphological variation in Crouzon syndrome patients. Additionally, to develop a non-radiation methodology for airway assessments. METHOD: In this study, 22 patients diagnosed with Crouzon syndrome (Age: 7.80 ± 5.63 years; Gender distribution: 11 females and 11 males) were analysed. The soft tissue surface and airway were three-dimensionally reconstructed, and the entire facial phenotype was topologized and converted into spatial coordinates. Geometric morphometrics was employed to verify the correlation and visualize dynamic phenotypic variation associated with airway volume. A total of 276 linear variables were automatically derived from 24 anatomical landmarks, and principal component analysis (PCA) identified the 20 most significant parameters for airway evaluation. Correlation analyses between parameters and airway volume were performed. Then, patients were classified into three groups based on airway volume, and the differences among the groups were compared for evaluating the differentiating effectiveness of parameters. RESULTS: The facial phenotype was strongly correlated with the airway (coefficient: 0.758). Morphological variation was characterized by (i) mandibular protrusion and anticlockwise rotation; (ii) midface retrusion; (iii) supraorbital frontward and (iv) lengthening of the facial height. All the anthropometric parameters were strongly associated with the airway, and the differences among the groups were statistically significant. CONCLUSION: This study confirmed the strong correlation between facial phenotype and airway parameters in Crouzon syndrome patients. Despite the development of the airway, pathological midface retrusion was still aggravated, suggesting that surgical intervention was inevitable. Three-dimensional facial anthropometry has potential as a non-radiation examination for airway evaluation.

Association of cranial base suture/synchondrosis fusion with severity of increased intracranial pressure in Crouzon syndrome.

This study investigated how the fusion states of the cranial base is related to the degree of increased intracranial pressure (ICP) in patients with Crouzon syndrome. This retrospective cohort study enrolled patients who were diagnosed with Crouzon syndrome between May 2007 and April 2022. We categorized the patients into three groups: A, B, and C, according to the severity of increased ICP and the number of cranial vault remodeling procedures for corrective operation. The preoperative fusion states of the cranial base sutures/synchondroses were examined using facial bone computed tomography and compared between groups. Overall, 22 patients were included in Groups A, B, and C, including 8, 7, and 7 patients, respectively. The preoperative average grades of the total cranial base suture/synchondrosis fusion appeared to significantly increase with severity, except for the frontoethmoidal suture, which showed the opposite tendency. In the subgroup analysis, frontosphenoidal, sphenoparietal, sphenosquamosal, parietomastoid, and occipitomastoid suture and petro-occipital synchondrosis were associated with earlier fusion in the more severe group. Premature closure of the cranial base sutures/synchodroses seems to be associated with increased ICP severity in patients with Crouzon syndrome. Precise evaluation of minor sutures/synchondroses at the first visit might help build subsequent operative plans and predict disease prognosis.

Perioperative Management of Obstructive Sleep Apnea in Patients With Syndromic Craniosynostosis Undergoing LeFort III Osteotomy With Distraction: A Case Series.

Study Design: Retrospective observational study. Objective: The purpose of this publication is to address the absence of literature detailing respiratory management in patients with syndromic craniosynostosis and obstructive sleep apnea during the immediate postoperative interval following LeFort III advancement with placement of distraction hardware but prior to sufficient midface advancement. Methods: After IRB approval, the investigators retrospectively selected candidates for inclusion in this case series. The sample was composed of four patients ranging from 10 to 19 years of age undergoing LeFort III midface advancement during a one-year span at a single tertiary care center. All operations were performed by a single surgeon. Three of the selected patients suffered significant obstructive sleep apnea necessitating the operation, as determined by polysomnography. One patient experienced persistent apnea postoperatively requiring prolonged ICU level care. Results: Three of the four patients had severe OSA diagnosed by polysomnography with a median AHI of 28.3. Two of the three patients with preoperative OSA experienced no untoward respiratory compromise in the immediate postoperative period; one required nightly oxygen tent and the other required no supplemental oxygen. Patient 1 experienced significant postoperative respiratory distress with nightly apneic episodes and desaturations requiring supplemental oxygen and frequent stimulation. Conclusions: The present study suggests that early involvement of sleep medicine and management of patient expectations is vital. Extremely close postoperative monitoring in the ICU is necessary. Future studies are needed to protocolize perioperative management of obstructive sleep apnea in patients undergoing LeFort III osteotomy prior to initiation and completion of midface advancement.

Crouzon syndrome with acanthosis nigricans: a case report and literature review.

Crouzon syndrome with acanthosis nigricans is an autosomal dominant disease, with typical features of classic Crouzon craniosynostosis, verrucous hyperplasia, and hyperpigmentation of the skin. While several mutations in FGFR2 cause classic Crouzon syndrome, Crouzon syndrome with acanthosis nigricans results from a point mutation in the fibroblast growth factor receptor 3 gene (FGFR3). We report the case of an 8-year-old Vietnamese girl diagnosed with Crouzon syndrome with acanthosis nigricans, showing typical clinical features, including a crouzonoid face and dark plaques on the skin. Genetic testing showed a missense variation in FGFR3, associated with Crouzon syndrome with acanthosis nigricans. Following diagnosis, we treated acanthosis nigricans with 10% urea cream. This case study and literature review discuss the cutaneous manifestations and dermatological treatments while demonstrating the importance of clinical examination and evaluation of the patient's medical history during diagnosis. Our findings contribute to the global pool of data, providing practical insights into the manifestations of Crouzon syndrome.

Progressive myelinated retinal nerve fibers in a 10-year-old boy with Crouzon syndrome after craniofacial surgery.

Purpose: We present a case of a 10-year-old boy with Crouzon syndrome that demonstrates progressive myelinated retinal nerve fibers (MRNF). Observations: A 10-year-old boy was referred for ophthalmic examination due to clusters of opaque white fibers around his optic nerve. Past surgical history includes craniofacial surgery at 3 years of age secondary to the deteriorating vision from increased intracranial pressure and papilledema. Upon examination (now 6.5 years post-craniofacial surgery), the patient denied any ocular complaints. The fundus examination showed progressively enlarged myelination of the retinal nerve fiber layer (right eye > left eye). Although previous cases of MRNF with Crouzon syndrome have been reported, our case is unique given its post-operative status with early onset of MRNF. Conclusion and importance: This case report documents the photographic progression of bilateral myelinated retinal nerve fibers (MRNF) in a pediatric case of Crouzon syndrome post-craniofacial surgery secondary to increased intracranial pressure and papilledema. Based on our patient, craniofacial decompression surgery may not prevent the development of MRNF. The exact mechanisms of MRNF are still being studied. Further investigations correlating craniofacial surgeries, increased intracranial pressure, and progression of myelinated retinal nerve fibers are needed to understand this process.

An unusual presentation of bilateral optic pathway glioma in Crouzon Syndrome.

Crouzon Syndrome is a genetic craniosynostosis disorder associated with a high risk of ophthalmologic sequelae secondary to structural causes. However, ophthalmologic disorders due to intrinsic nerve aberrations in Crouzon Syndrome have not been described. Optic pathway gliomas (OPGs) are low grade gliomas that are intrinsic to the visual pathway, frequently associated with Neurofibromatosis type 1 (NF-1). OPGs involving both optic nerves without affecting the optic chiasm are rarely seen outside of NF-1. We report an unusual case of bilateral optic nerve glioma without chiasmatic involvement in a 17-month-old male patient with Crouzon Syndrome without any clinical or genetic findings of NF-1. This case suggests that close ophthalmologic follow up and orbital MRIs may benefit patients with Crouzon Syndrome.

Unravelling the pathogenesis of foramen magnum stenosis in patients with severe achondroplasia: a CT-based comparison with age-matched controls and FGFR3 craniosynostosis syndromes.

OBJECTIVE: Foramen magnum(FM) stenosis can be responsible for acute and chronic damage to the cervicomedullary junction in children with achondroplasia. The bony anatomy and patterns of suture fusion of the FM in this context are incompletely understood, yet becoming increasingly important in the light of novel medical therapies for achondroplasia. The objective of this study was to describe and quantify bony anatomy and fusion patterns of FM stenosis in patients with achondroplasia using CT scans, comparing them to age-matched controls and other FGFR3 craniosynostosis patients. METHODS: Patients with achondroplasia and severe FM stenosis, classified as achondroplasia foramen magnum score(AFMS) grades 3 and 4, were identified from a departmental operative database. All had pre-operative CT scans of the craniocervical junction. Measurements obtained comprised sagittal diameter (SD), transverse diameter (TD), foramen magnum area, and opisthion thickness. Anterior and posterior interoccipital synchondroses (AIOS and PIOS) were graded by the extent of fusion. These measurements were then compared with CT scans from 3 age-matched groups: the normal control group, children with Muenke syndrome, and children with Crouzon syndrome with acanthosis nigricans (CSAN). RESULTS: CT scans were reviewed in 23 cases of patients with achondroplasia, 23 normal controls, 20 Muenke, and 15 CSAN. Children with achondroplasia had significantly smaller sagittal diameter (mean 16.2 ± 2.4 mm) compared to other groups (control 31.7 ± 2.4 mm, p < 0.0001; Muenke 31.7 ± 3.5 mm, p < 0.0001; and CSAN 23.1 ± 3.4 mm, p < 0.0001) and transverse diameters (mean 14.3 ± 1.8 mm) compared with other groups (control 26.5 ± 3.2 mm, p < 0.0001; Muenke 24.1 ± 2.6 mm, p < 0.0001; CSAN 19.1 ± 2.6 mm, p < 0.0001). This translated into a surface area which was 3.4 times smaller in the achondroplasia group compared with the control group. The median grade of the AIOS fusion achondroplasia group was 3.0 (IQR 3.0-5.0), which was significantly higher compared with the control group (1.0, IQR 1.0-1.0, p < 0.0001), Muenke group (1.0, IQR 1.0-1.0, p < 0.0001), and CSAN (2.0, IQR 1.0-2.0, p < 0.0002). Median PIOS fusion grade was also highest in the achondroplasia group (5.0, IQR 4.0-5.0) compared with control (1.0, IQR 1.0-1.0, p < 0.0001), Muenke (2.5, IQR 1.3-3.0, p < 0.0001), and CSAN (4.0, IQR 4.0-4.0, p = 0.2). Distinct bony opisthion spurs projecting into the foramen magnum were seen in achondroplasia patients but not others, resulting in characteristic crescent and cloverleaf shapes. CONCLUSION: Patients with AFMS stages 3 and 4 have significantly reduced FM diameters, with surface area 3.4 times smaller than age-matched controls. This is associated with premature fusion of the AIOS and PIOS in comparison with controls and other FGFR3-related conditions. The presence of thickened opisthion bony spurs contributes to stenosis in achondroplasia. Understanding and quantifying bony changes at the FM of patients with achondroplasia will be important in the future quantitative evaluation of emerging medical therapies.

Long-term follow-up of a patient diagnosed with Crouzon syndrome who underwent Le Fort I and III distraction osteogenesis using a rigid external distractor system.

OBJECTIVE: This case report describes the successful treatment of a patient with Crouzon syndrome with severe midfacial deficiency and malocclusion, including reverse overjet. MATERIALS AND METHODS: In Phase I treatment, maxillary lateral expansion and protraction were performed. In Phase II treatment, after lateral expansion of the maxilla and leveling of the maxillary and mandibular dentition, an orthognathic approach including simultaneous Le Fort I and III osteotomies with distraction osteogenesis (DO) was used to improve the midfacial deficiency. RESULTS: After DO, 12.0 mm of the medial maxillary buttress and 9.0 mm of maxillary (point A) advancement were achieved, which resulted in a favorable facial profile and stable occlusion. CONCLUSION: Even after 8 years of retention, the patient's profile and occlusion were preserved without any significant relapse.

Mysterious Bilateral Foot Pain in a Child With Crouzon Syndrome.

Crouzon syndrome (CS) is a rare autosomal dominant disorder that requires care from a multidisciplinary team and early surgical management to minimize complications. Despite the shared similarities across craniosynostoses, CS can be differentiated by the presence of normal bone development of the hands and feet and hypertelorism (large distance between the eyes). Other common features include midface hypoplasia, shallow orbits, ocular proptosis, and dental abnormalities including possible bifid uvula or V-shaped maxillary arch. In this report, we present a case of prolonged foot pain in a four-year and two-month-old boy with CS; we also engage in a brief review of the literature. The patient's physical exam and laboratory work were unremarkable on the initial presentation. Radiographic films showed signs of potential demineralization of bone tissue. He was prescribed calcium and vitamin D supplementation with complete resolution of his symptoms at the three-month follow-up visit.