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.

LeFort III Versus Monobloc Frontofacial Advancement: A Comparative Analysis of Soft Tissue Changes.

INTRODUCTION: The LeFort III and monobloc are commonly used midface advancement procedures for patients with syndromic craniosynostosis with well characterized postoperative skeletal changes. However, the differential effects of these procedures on facial soft tissues are less understood. The purpose of this study was to critically analyze and compare the effects of these 2 procedures on the overlying soft tissues of the face. METHODS: Frontal and lateral preoperative and postoperative photographs of patients undergoing monobloc or LeFort III were retrospectively analyzed using ImageJ to measure soft tissue landmarks. Measurements included height of facial thirds, nasal length and width, intercanthal distance, and palpebral fissure height and width. Facial convexity was quantified by calculating the angle between sellion (radix), subnasale, and pogonion on lateral photographs. RESULTS: Twenty-five patients with an average age of 6.7 years (range 4.8-14.5) undergoing monobloc (n=12) and LeFort III (n=13) were identified retrospectively and analyzed preoperatively and 6.4±3.6 months postoperatively. Patients undergoing LeFort III had a greater average postoperative increase in facial convexity angle acuity (28.2°) than patients undergoing monobloc (17.8°, P =0.021). Patients in both groups experience postoperative increases in nasal width ( P <0.001) and decreases in palpebral fissure height ( P <0.001). CONCLUSIONS: Both subcranial LeFort III advancements and monobloc frontofacial advancements resulted in significant changes in the soft tissues. Patients undergoing LeFort III procedures achieved greater acuity of the facial convexity angle, likely because the nasion is not advanced with the LeFort III segment.

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.

Molecular Scalpels: The Future of Pediatric Craniofacial Surgery?

SUMMARY: CRISPR-Cas genome editing tools are among the most substantial advances in the life sciences in modern history. Single-dose gene therapies to correct pathogenic mutations have moved quickly from bench to bedside, with several therapeutics designed by CRISPR pioneers entering various stages of clinical investigation. Applications of these genetic technologies are poised to reshape the practice of both medicine and surgery. Many of the most morbid conditions treated by craniofacial surgeons are syndromic craniosynostoses caused by mutations in fibroblast growth factor receptor genes, including Apert, Pfeiffer, Crouzon, and Muenke syndromes. The fact that pathogenic mutations in these genes are recurrent in the majority of affected families presents a unique opportunity to develop "off-the-shelf" gene editing therapies to correct these mutations in affected children. The therapeutic potential of these interventions could reshape pediatric craniofacial surgery, potentially first eliminating the need for midface advancement procedures in affected children.

Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

BACKGROUND: Crouzon syndrome is characterized by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-center retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates whether the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphologic outcomes. METHODS: Patients with Crouzon syndrome who underwent FFMBA with internal distraction [Hôpital Necker-Enfants Malades (Paris, France)] or external distraction [Great Ormond Street Hospital for Children (London, United Kingdom)] were compared. Digital Imaging and Communications in Medicine files of preoperative and postoperative computed tomographic scans were converted to three-dimensional bone meshes and skeletal movements were assessed using nonrigid iterative closest point registration. Displacements were visualized using color maps and statistical analysis of the vectors was undertaken. RESULTS: Fifty-one patients met the strict inclusion criteria. Twenty-five underwent FFMBA with external distraction and 26 with internal distraction. External distraction provides a preferential midfacial advancement, whereas internal distractors produce a more positive movement at the lateral orbital rim. This confers good orbital protection but does not advance the central midface to the same extent. Vector analysis confirmed this to be statistically significant ( P < 0.01). CONCLUSIONS: Morphologic changes resulting from monobloc surgery differ depending on the distraction technique used. Although the relative merits of internal and external distraction still stand, it may be that external distraction is more suited to addressing the midfacial biconcavity seen in syndromic craniosynostosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Two-Center Review of Posterior Vault Expansion following a Staged or Expectant Treatment of Crouzon and Apert Craniosynostosis.

BACKGROUND: The timing of posterior cranial expansion for the management of intracranial pressure can be "staged" by age and dysmorphology or "expectant" by pressure monitoring. The authors report shared outcome measures from one center performing posterior vault remodeling (PCVR) or distraction (PVDO) following a staged approach and another performing spring-assisted expansion (SAPVE) following an expectant protocol. METHODS: Apert or Crouzon syndrome patients who underwent posterior expansion younger than 2 years were included. Perioperative outcomes and subsequent cranial operations were recorded up to last follow-up and intracranial volume changes measured and adjusted using growth curves. RESULTS: Thirty-eight patients were included. Following the expectant protocol, Apert patients underwent SAPVE at a younger age (8 months) than Crouzon patients (16 months). The initial surgery time was shorter but total operative time, including device removal, was longer for PVDO (3 hours 52 minutes) and SAPVE (4 hours 34 minutes) than for PCVR (3 hours 24 minutes). Growth-adjusted volume increase was significant and comparable. Fourteen percent of PCVR, 33% of PVDO, and 11% of SAPVE cases had complications, but without long-term deficits. Following the staged approach, 5% underwent only PVDO, 85% had a staged posterior followed by anterior surgery, and 10% required a third expansion. Following the expectant approach, 42% of patients had only posterior expansion at last follow-up, 32% had a secondary cranial surgery, and 26% had a third cranial expansion. CONCLUSION: Two approaches involving posterior vault expansion in young syndromic patients using three techniques resulted in comparable early volume expansion and complication profiles. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Morphology of the Occipital Bones and Foramen Magnum Resulting From Premature Minor Suture Fusion in Crouzon Syndrome.

To identify skull-base growth patterns in Crouzon syndrome, we hypothesized premature minor suture fusion restricts occipital bone development, secondarily limiting foramen magnum expansion.Skull-base suture closure degree and cephalometric measurements were retrospectively studied using preoperative computed tomography (CT) scans and multiple linear regression analysis.Evaluation of multi-institutional CT images and 3D reconstructions from Wake Forest's Craniofacial Imaging Database (WFCID).Sixty preoperative patients with Crouzon syndrome under 12 years-old were selected from WFCID. The control group included 60 age- and sex-matched patients without craniosynostosis or prior craniofacial surgery.None.2D and 3D cephalometric measurements.3D volumetric evaluation of the basioccipital, exo-occipital, and supraoccipital bones revealed decreased growth in Crouzon syndrome, attributed solely to premature minor suture fusion. Spheno-occipital (ß = -398.75; P < .05) and petrous-occipital (ß = -727.5; P < .001) suture fusion reduced growth of the basioccipital bone; lambdoid suture (ß = -14 723.1; P < .001) and occipitomastoid synchondrosis (ß = -16 419.3; P < .001) fusion reduced growth of the supraoccipital bone; and petrous-occipital suture (ß = -673.3; P < .001), anterior intraoccipital synchondrosis (ß = -368.47; P < .05), and posterior intraoccipital synchondrosis (ß = -6261.42; P < .01) fusion reduced growth of the exo-occipital bone. Foramen magnum morphology is restricted in Crouzon syndrome but not directly caused by early suture fusion.Premature minor suture fusion restricts the volume of developing occipital bones providing a plausible mechanism for observed foramen magnum anomalies.

An Elderly Patient With Crouzon Syndrome Treated With Monobloc Distraction.

Monobloc advancement by distraction osteogenesis is the treatment of choice in patients with syndromic craniosynostosis. This procedure is usually performed at 18 to 24 months/5 to 10 years of age. Herein, we present the case of a male patient with Crouzon syndrome who underwent monobloc advancement at the age of 62 years. Although the patient lived a normal life (employed, married, and being a father of a daughter), he visited our hospital for surgical improvement in facial esthetics. The patient underwent monobloc advancement by distraction osteogenesis. He was satisfied with the postoperative esthetic improvement and did not experience any major complications. This case highlights the fact that patients with syndromic craniosynostosis desire esthetic improvement and suggests that multidisciplinary treatment involving both the neuro and plastic surgeons is important in such cases.

Behavioral, Learning Skills, and Visual Improvement in Crouzon Syndrome Patient Following Late Posterior Vault Distraction Osteogenesis.

BACKGROUND: It is well accepted among craniofacial surgeons that surgery does not improve mental status but does prevent worsening or deterioration of cognitive and mental function. In this report, we describe significant improvement in behavioral, learning skills and visual acuity for a Crouzon patient who underwent late posteriorvault distraction osteogenesis. METHODS: A 9-year-old Crouzon patient was referred to our hospital, presenting severe intracranial hypertension. The patient had previously undergone a strip craniectomy in early infancy at another medical institution, but there was no subsequent follow-up. Magnetic resonance imaging showed Chiari type I malformation and fundoscopy revealed papilledema. At the time of referral, the patient was not attending a regular school, had not acquired reading skills, was unable to concentrate, and could not accomplish school-related tasks that were standard for children in his age group. RESULTS: The patient underwent posterior vault distraction osteogenesis and showed concentration improvement and acquisition of fluent reading skills. Chiari type I malformation resolved as well as papilledema. visual acuity improved at Snellen test preoperatively from 20/200 to 20/60 at postoperative test. Ventricle size remained unchanged subsequent to performance of the posterior cranial vault distraction. The occipital veins were less visible upon clinical examination and less pronounced when palpated, and the bruit had completely disappeared. CONCLUSION: Late posterior vault distraction osteogenesis can improve behavioral, learning skills and visual acuity as shown in this 9-year-old Crouzon patient.

Subcranial Midface Advancement in Patients with Syndromic Craniosynostosis.

Patients with syndromic craniosynostosis can present with midface hypoplasia, abnormal facial ratios, and obstructive sleep apnea. These symptoms can all be improved with midface advancement, but it is essential to evaluate the specific morphologic characteristics of each patient's bony deficiencies before offering subcranial advancement. Midface hypoplasia in Crouzon syndrome is evenly distributed between the central and lateral midface and reliably corrected with Le Fort III distraction. In contrast, the midface hypoplasia in Apert/Pfeiffer syndromes occurs in both an axial and a sagittal plane, with significantly more nasomaxillary hypoplasia compared with the orbitozygomatic deficiency.

Frontofacial Reconstruction Technique Modification With Preservation of Blood Supply to the Monobloc Segment.

ABSTRACT: Craniosynostosis syndromes, including Apert Syndrome, Pfeiffer Syndrome, and Crouzon Syndrome, share similar phenotypes, including bicoronal craniosynostosis, midface hypoplasia, hypertelorism, and exorbitism. The standard surgical treatment for these craniofacial abnormalities is monobloc osteotomy with distraction osteogenesis. Complications of this technique include the failure of osteogenesis or resorption of the frontal bone. The authors propose an alternative surgical technique with a frontal arch in continuity with the midface segment to ensure vascularization to anterior and posterior borders of distraction. A case report of an 8-year-old female patient with Apert Syndrome is reported using our technique. Our frontal arch monobloc distraction procedure preserves blood supply to a cranial component of the monobloc segment site that becomes the anterior portion of distraction rather than with the traditional devascularized frontal bone flap. This technique modification should improve osteogenesis outcomes by preventing resorption or failure of bone formation.

Correction of Midface Deficiency in Patient With Crouzon Syndrome by Orthognathic Surgery and Patient Specific Facial Implant: Case Report.

ABSTRACT: Crouzon syndrome, also known as craniofacial dysostosis, is an autosomal dominant inherited disease characterized by early cranial fusion and consequential craniofacial malformations. In patients with Crouzon syndrome, the growth of the midface is affected due to early fusion of the cranial base, which results in exophthalmos, ocular ptosis, midface deficiency, and maxillary retrognathism. Frontofacial advancement using Le Fort III osteotomy is the conventional method for treating patients with Crouzon syndrome. However, this procedure has drawbacks such as extensive operation field and high possibility of serious complications (eg, meningitis). For patients with mild symptoms, facial esthetics and proper occlusion can be promoted through conventional orthognathic surgery, but midface deficiency cannot be completely resolved. Thus, in this case report, midface augmentation was performed for a patient with Crouzon syndrome by undergoing conventional orthognathic surgery, along with patient-specific implants made using a 3D virtual technique. Implants were 3D printed using polyetherketoneketone and simultaneously implanted during the orthognathic surgery. After the surgery, not only were the patient's occlusion and facial esthetics improved, but also exophthalmos and ocular ptosis were reduced by the midfacial augmentation effect of patient-specific implants placed in the midface. Since the implants were made exactly as what surgeons have intended through computer-aided design (CAD)/computer-aided manufacturing (CAM) and 3D printing techniques, problems such as under-/over-correction were avoided. In addition, the possibility of implant malpositioning was minimized using surgical stents as implants were passively fitted on the patient's bone surface. This case verified that the application of 3D technology to the field of oral and maxillofacial surgery can reduce the invasiveness of surgery and improve the accuracy of the operation. Therefore, by using cutting-edge technologies, the field of oral and maxillofacial surgery is expected to be developed further in the near future.

Secondary Le Fort III after Early Fronto-Facial Monobloc Normalizes Sleep Apnea in Faciocraniosynostosis: A Cohort Study.

BACKGROUND: This study aims to assess the improvement of sleep apnea after secondary Le Fort III facial advancement with distraction (LF3) in faciocraniosynostosis (FCS) patients with sleep apnea who have previously undergone fronto-facial monobloc advancement (FFMBA) with distraction. METHODS: Patients having undergone secondary LF3 were selected from a cohort of FCS patients with documented sleep apnea who had previously undergone fronto-facial monobloc advancement. Patient charts and polysomnographic records were reviewed. Apnea-hypopnea index (AHI) was recorded before and at least 6 months after secondary LF3. The primary outcome was normalization of AHI (less than 5/h was considered normal). Hierarchical multilevel analysis was performed to predict postoperative AHI evolution. RESULTS: Seventeen patients underwent a secondary LF3, 7.0 ± 3.9 years after the primary FFMBA. The mean age was 9.6 ± 3.9 years. A total of 15 patients (88%) normalized their AHI. Two of four patients were decannulated (50%). There was a statistically significant decrease in AHI (preoperative AHI 21.5/h vs. 3.9/h postoperatively, p=0.003). Hierarchic multilevel modeling showed progressive AHI decrease postoperatively. CONCLUSION: Secondary LF3 improves residual or relapsing sleep apnea in FCS patients who have previously had FFMBA.

Frontofacial Monobloc Advancement With Internal Distraction: Surgical Technique and Osteotomy Guide.

BACKGROUND: Craniosynostosis are cranial deformities resulting from the early closure of 1 or more sutures. Concomitant facial changes are complex and usually result from the involvement of multiple sutures, which may lead to restriction of cranial growth and brain expansion, ocular compression, and breathing difficulties. Surgical techniques to correct syndromic craniosynostosis have improved over time, considerably reducing the rate of complications of this procedure. OBJECTIVE: To describe in detail (step-by-step) and with pertinent anatomic considerations the technique of monobloc frontofacial advancement using internal distractors. METHODS: We describe the monobloc frontofacial advancement technique with the use of internal distractors, which we use in patients with primary syndromic craniosynostosis (Apert, Crouzon, and Pfeiffer) who have major facial hypoplasia and secondary respiratory repercussions. To illustrate this technique, the procedure was performed in 2 cranial models: an adult artificial acrylic skull of normal morphology for better evidence of anatomic repairs and a 3-dimensional printed infant skull from a tomography file obtained from a child diagnosed with Apert syndrome. RESULTS: The benefits of osteogenic distraction and better surgical timing for each procedure are presented. We presented the changes and details of osteotomies performed during the procedure, as well as anatomic details and care regarding the pterygomaxillary dysjunction. CONCLUSION: Monobloc frontofacial distraction is a procedure with widely demonstrated aesthetic and functional results, and this detailed step-by-step description may improve familiarity with the anatomic landmarks of the procedure and provide a better dynamic understanding of the distraction process.

Influence of Nonsyndromic Bicoronal Synostosis and Syndromic Influences on Orbit and Periorbital Malformation.

BACKGROUND: Oculoorbital disproportion in patients with craniosynostosis has similarities and dissimilarities between syndromic and nonsyndromic cases. The authors hypothesized that these two conditions have specific individual influences as they relate to development of the orbital and periorbital skeletons. METHODS: A total of 133 preoperative computed tomography scans (nonsyndromic bicoronal synostosis, n = 38; Apert syndrome bicoronal synostosis subtype, n = 33; Crouzon syndrome bicoronal synostosis subtype, n = 10; controls, n = 52) were included. Craniometric and volumetric analyses related to the orbit and periorbital anatomy were performed. RESULTS: Orbital cavity volume was mildly restricted in nonsyndromic bicoronal synostosis (7 percent, p = 0.147), but more so in Apert and Crouzon syndromes [17 percent (p = 0.002) and 21 percent (p = 0.005), respectively]. The sphenoid side angle in Apert syndrome was wider than when compared to Crouzon syndrome (p = 0.043). The ethmoid side angle in Apert patients, however, was narrower (p = 0.066) than that in Crouzon patients. Maxilla anteroposterior length was more restricted in Apert syndrome than Crouzon syndrome (21 percent, p = 0.003) and nonsyndromic cases (26 percent, p < 0.001). The posterior nasal spine position was retruded in Crouzon syndrome (39 percent, p < 0.001), yet the anterior nasal spine position was similar in Apert and Crouzon syndromes. CONCLUSIONS: Orbit and periorbital malformation in syndromic craniosynostosis is likely the combined influence of syndromic influences and premature suture fusion. Apert syndrome expanded the anteriorly contoured lateral orbital wall associated with bicoronal synostosis, whereas Crouzon syndrome had more infraorbital rim retrusion, resulting in more severe exorbitism. Apert syndrome developed maxillary hypoplasia, in addition to the maxillary retrusion, observed in Crouzon syndrome and nonsyndromic bicoronal synostosis patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Hypertelorbitism Corrected by Facial Bipartition Improves Exotropia.

BACKGROUND: The purpose of this study was to detail perioperative ophthalmologic evaluations to characterize functional ocular outcomes after facial bipartition surgery. METHODS: Patients with hypertelorbitism who underwent facial bipartition surgery were studied specifically for eye motility disorders by separating patients into rare craniofacial clefts (midline and paramedian) (n = 34) and craniofacial dysostosis (Apert, Crouzon, and Pfeiffer) (n = 74). Preoperative and postoperative (12 months) ophthalmologic examinations (with depth perception tests), computed tomography scans, and magnetic resonance imaging scans were analyzed. RESULTS: Among craniofacial cleft patients, mean interdacryon distance was reduced from 39 ± 4 mm to 17 ± 2 mm, with strabismus improved from 88 percent (exotropia 82 percent) preoperatively to only 29 percent postoperatively. Depth perception improved to a lesser degree, with abnormal tests at a rate of 79 percent preoperatively to 56 percent postoperatively. Wider hypertelorbitism had a higher degree of strabismus. Among craniofacial dysostotic patients, mean interdacryon distance was reduced from 37 ± 3 mm to 17 ± 2 mm, and strabismus improved from 55 percent to only 14 percent. Depth perception improved to a lesser degree, with 68 percent abnormal tests preoperatively and 46 percent postoperatively. Apert patients had more V-pattern strabismus and exotropia (79 percent) than did other craniofacial dysostosis patients (42 percent). CONCLUSIONS: The authors' data indicate that facial bipartition for hypertelorbitism-known to improve periorbital aesthetics-also improves eye motility disturbances. Thus, vision problems related to exotropia should be considered a functional indication for facial bipartition surgery in patients with hypertelorbitism. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Crouzon Syndrome Anatomy, Usefulness of Vestibular Orientation.

ABSTRACT: Spatial resolution of computerized tomographic scanner has reached a level to which accurate anatomic measurements could be done in. Three-dimensional accurate measurements require a reliable referential system. In craniology landmarks are usually selected in the skull base. For craniofacial malformation the classical landmarks are of no help so the authors have used the vestibular orientation to study a series of 50 Crouzon syndrome computerized tomographic scan and compare the results (shape, position, linear mensuration, volumes…) with 122 controls in unaffected patients. The authors have confirmed Crouzon description of a high level of polymorphism in phenotypes, the authors propose an organigram to understand the abnormal growth patterns in crouzon syndrome, which lead to such consequences. This polymorphism implies that the planning of surgical treatment should be tailored for each case.

Zygomatic repositioning and Le Fort II distraction with intraoral devices in Apert syndrome: A case report.

The aim of this case report is to describe the surgical technique and outcome using internal intraoral distraction devices in LeFort II distraction with zygomatic repositioning (LF2ZR). In Apert syndrome the midface is characterized by a complex hypoplasia, with the central part being more affected than the lateral orbito-zygomatic complex. In LF2ZR, the zygomas are repositioned and internally fixated, and the central midface is further advanced through a LeFort II distraction. In previous publications, the distraction has been performed using external halo-based devices. It seems that the LF2ZR procedure can be planned and performed with adequate accuracy using virtual surgical planning tools. Knowledge about the possibility of using internal intraoral distraction devices in LF2ZR is important, as the inconspicuous placement of intraoral devices can be advantageous for some patients.

Posterior Vault Distraction Outcomes in Patients With Severe Crouzon Syndrome Resulting from Ser347Cys and Ser354Cys Mutations.

BACKGROUND: In this study, the authors present the outcomes of 4 patients with a severe form of Crouzon syndrome characterized by mutation of fibroblast growth factor receptor 2 (FGFR2) c.1040 C > G p.Ser347Cys or the pathogenic c.1061C > G p.Ser354Cys variant of FGFR2, who underwent posterior vault distraction osteogenesis (PVDO) to alleviate elevated intracranial pressure. METHODS: Patients with diagnosed Crouzon syndrome who were found by genetic testing to have an FGFR2 c.1040 C > G p.Ser347Cys mutation or the c.1061C > G p.Ser354Cys variant were included. Outcome data and presence of hydrocephalus, Chiari Malformation type I (CMIs), and the presence/absence of a tracheostomy were recorded. RESULTS: Three patients with the FGFR2 c.1040 C > G p.Ser347Cys mutation and 1 with the pathogenic FGFR2 c.1061C > G p.Ser354Cys variant were identified as having characteristics of severe Crouzon syndrome. The mean age at PVDO was 15 months and the mean posterior advancement was 20 mm. All 4 patients experienced sufficient relief of the elevated intracranial pressure from the PVDO to prevent the need for shunt placement, stabilize the ventricular dimensions (n = 2), and resolve the CMIs (n = 2). Intracranial pressure screening ruled out malignant cerebrospinal fluid volume increase. CONCLUSIONS: PVDO effectively prevented hydrocephalus and resolved CMIs, successfully alleviating intracranial pressure and maximizing clinical outcomes for patients with severe Crouzon syndrome.