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.

The foramen magnum in scaphocephaly.

PURPOSE: The foramen magnum (FM) presents various alterations in craniosynostoses, such as brachycephaly or Crouzon syndrome. However, to date, no study has been devoted to its morphology and morphometry in scaphocephaly, which is the most common of cranial deformities resulting from premature fusion of cranial sutures. METHODS: We assessed the morphology and morphometry of FM using preoperative thin-cut CT scans of 107 children with non-syndromic sagittal craniosynostosis aged 1-12 months (mean age 5.38 months). A series of sagittal and transverse dimensions were taken and the FM area was calculated in each case. Obtained data were compared to the age-matched control group of 101 normocephalic children. RESULTS: Dolichotrematous type of FM was dominant in the scaphocephaly group and observed in 63/107 cases (58.9%). The mean FM area in the scaphocephaly group was 519.64 mm2 and was significantly smaller compared to the control group (p = 0.0011). The transverse diameter and anterior sagittal diameter were also significantly smaller (p = 0.0112 and p = 0.0003, respectively). CONCLUSION: The area of FM in scaphocephaly is smaller compared to normal individuals. This is associated with a significant reduction of the width of FM in children with sagittal craniosynostosis. FM in scaphocephaly is larger than in other reported series of children with brachycephaly or Crouzon syndrome.

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.

Crouzon syndrome and the eye: An overview.

The current literature review aims to evaluate the ocular findings and associated ophthalmic features in Crouzon syndrome. Craniosynostoses are syndromes characterized by premature fusion of sutures of the skull and Crouzon syndrome is the most common of the craniosynostosis syndromes. Early fusion of sutures results in craniofacial anomalies, including abnormalities of the orbits. To prepare this review of the ophthalmic findings in this disorder, an organized search on online databases such as PubMed, Scopus, Cochrane Library, and Ovid was carried out. The key terms searched were "Crouzon", "craniosynostosis", "eye" and "ophthalmic", and 51 research items were found. A total of 17 articles were included after scrutiny of the databases and a further 25 articles were added after augmented search. A detailed review was performed from the final 42 articles. A comprehensive description of associated anomalies is given along with the author's own technique of surgical management in cases with Crouzon syndrome having bilateral luxation bulbi with exposure keratopathy. However, for optimum management of cranial and oculo-facial dysmorphisms, a multidisciplinary team of specialists is required.

Mechanical loading of cranial joints minimizes the craniofacial phenotype in Crouzon syndrome.

Children with syndromic forms of craniosynostosis undergo a plethora of surgical interventions to resolve the clinical features caused by the premature fusion of cranial sutures. While surgical correction is reliable, the need for repeated rounds of invasive treatment puts a heavy burden on the child and their family. This study explores a non-surgical alternative using mechanical loading of the cranial joints to prevent or delay craniofacial phenotypes associated with Crouzon syndrome. We treated Crouzon syndrome mice before the onset of craniosynostosis by cyclical mechanical loading of cranial joints using a custom designed set-up. Cranial loading applied to the frontal bone partially restores normal skull morphology, significantly reducing the typical brachycephalic appearance. This is underpinned by the delayed closure of the coronal suture and of the intersphenoidal synchondrosis. This study provides a novel treatment alternative for syndromic craniosynostosis which has the potential to be an important step towards replacing, reducing or refining the surgical treatment of all craniosynostosis patients.

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.

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.

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.

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.

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.

Crouzon's Syndrome with a Dominant Sinus Pericranii Draining Transverse Sinus: Report of a Rare Association and Review of Literature.

INTRODUCTION: Crouzon's syndrome and sinus pericranii (SP) are rare entities. Only few cases having both the features are reported. SP most commonly drains in relation to superior sagittal sinus and their communication to major posterior dural sinuses is rare. CASE REPORT: We report a rare case of Crouzon's syndrome with SP at a suboccipital location with termination of left transverse sinus into the SP draining further through the extracranial suboccipital and extravertebral cervical venous plexi into external jugular veins. Distal transverse sinus and sigmoid sinus on the left side were absent. CONCLUSION: Crouzon's syndrome with SP is an extremely rare entity. SP with communication to major posterior dural venous sinuses is also rare and mostly associated with multi-suture craniosynostosis. Management depends on the volume of venous blood they are draining. Most of them are dominant type and their occlusion is not feasible. Preoperative diagnosis of a dominant SP is essential for proper surgical planning as it needs to be preserved mandatorily to prevent cerebral venous infarction.