Orbital Dysmorphology in Untreated Children with Crouzon and Apert Syndromes:

Orbital Bone Fracture Repair Evaluation Through 3-Dimensional Computational Reconstruction and Orbital Volumetric Assessment

Background

Three-dimensional (3D) models generated from computed tomography (CT) images efficiently and accurately complement surgical comprehension. Additionally, computer modeling provides a substrate for comparative analysis of the treated orbit volume. This study aimed to investigate cases of orbital bone fractures with regard to orbital-defect correction, through 3D computational structural modeling and evaluation of orbital volume.

Methods

A total of 136 cases of orbital fractures with a diagnosis and surgical treatment were identified, of which 15 were selected based on inclusion and exclusion criteria. The construction of the preoperative and postoperative 3D models was based on CT images, supported by a medical imaging design system; this technique enabled the calculation of orbital volumetric measurements with the normal contralateral orbit as a reference.

Results

Three-dimensional modeling in the preoperative and postoperative periods was performed for each patient. This study revealed that (1) preoperatively, the affected side had greater volume followed by postoperative reduction and (2) after surgical correction, the affected side had smaller volume and was equivalent to the unaffected side. However, there were no statistically significant differences between the periods (preoperative and postoperative) with regard to the mean and distribution of orbital volume or between the mean orbital volumes of the 2 sides.

Conclusions

Using 3D computer modeling of bone structures, it is possible to evaluate orbital bone fractures after surgical correction. The effectiveness of preoperative and postoperative treatments was confirmed by comparing orbital volumetrics. It was not possible to assess soft tissues due to postoperative edema.

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.

Tunneled Paranasal Augmentation Using Diced Autologous Costal Cartilage in Asian Rhinoplasty: A Comparative Study

Due to the prevalence of anterior maxilla dysplasia in Asian population, paranasal concavity is a common accompaniment to low nose, but its impact on facial harmonization is often underestimated. A retrospective comparative study was conducted on patients diagnosed as low nose with paranasal concavity between June 2017 and June 2021, with a total of 56 patients followed up successfully. The control and observation groups were established according to whether the paranasal augmentation was performed. Demographic data were collected. Cosmetic enhancement was quantitatively evaluated by sagittal planimetry, establishing related anatomical landmarks and measuring columella base prominence (CBP) and alar base prominence (ABP). Subjective evaluation concluded the patient-reported satisfaction (FACE-Q-Rhinoplasty Module and Facial Appearance Module) and the third-party physician assessment (Global Aesthetic Improvement Scale, GAIS).Significant improvements in CBP and ABP were reported both in the control and the observation group (p < 0.01). In postoperative intergroup comparisons, the observation group was superior to the control group regarding ABP values (2.5 ± 0.75 degrees, p < 0.01), FACE-Q-Facial scores (7.49 ± 3.70, p < 0.05), and GAIS scores (p < 0.05). However, no statistical difference was found in CBP values and FACE-Q-Rhinoplasty scores. Paranasal augmentation-related complications included asymmetry of alar bases (6.9%) and facial or intraoral foreign body sensation (34.5%). This study affirmed that paranasal augmentation using diced costal cartilage in rhinoplasty is a safe procedure effective in remedying paranasal concavity and improving facial satisfaction. LEVEL OF EVIDENCE::  IV.

Skeletal expansion via craniofacial distraction osteogenesis technique in syndromic craniosynostosis: impact on ophthalmic parameters

BACKGROUND

This study aims to compare the changes in ophthalmic parameters among syndromic craniosynostosis patients who underwent craniofacial skeletal expansion procedures via distraction osteogenesis (DO).

METHOD

A retrospective study was conducted involving syndromic craniosynostosis patients who underwent surgical expansion via the DO technique from the year 2012 to March 2022. Changes in six parameters which consist of visual acuity, refractive error, optic disc health, intraocular pressure, degree of proptosis and orbital volume were measured objectively pre and post-surgery. For categorical parameters, the Chi-square cross-tab test was done. Paired sample T-test was used for normally distributed variables. Wilcoxon signed-rank test was used for non-normally distributed data.

RESULTS

Visual impairment was present in 21.4% of eyes before surgery and increased to 28.5% post-surgery. Three patients had changes of refractive error post-surgery with one developed hypermetropia, another developed anisometropia and the last had improvement to no refractive error. Two patients had optic disc swelling which was resolved post-surgery. Intraocular pressure changes were inconsistent post-surgery. All patients achieved a significant reduction in the degree of proptosis post-surgery. Orbital volume calculation using computed tomography (CT) scans shows a significant increase in volume post-surgery for all patients.

CONCLUSION

Our study shows a significant increase in orbital volume post-surgery with a reduction in the degree of proptosis. Optic disc and nerve health improved after the surgery. Changes in terms of visual acuity, refractive error and IOP were inconsistent after the surgical intervention.

Orbital and Eyelid Characteristics, Strabismus, and Intracranial Pressure Control in Apert Children Treated by Endoscopic Strip Craniectomy versus Fronto-Orbital Advancement

Apert syndrome is characterized by eyelid dysmorphology, V-pattern strabismus, extraocular muscle excyclorotation, and elevated intracranial pressure (ICP). We compare eyelid characteristics, severity of V-pattern strabismus, rectus muscle excyclorotation, and ICP control in Apert syndrome patients initially treated by endoscopic strip craniectomy (ESC) at about 4 months of age versus fronto-orbital advancement (FOA) performed about 1 year of age.

Methods

Twenty-five patients treated at Boston Children's Hospital met inclusion criteria for this retrospective cohort study. Primary outcomes were magnitude of palpebral fissure downslanting at 1, 3, and 5 years of age, severity of V-pattern strabismus, rectus muscle excyclorotation, and interventions to control ICP.

Results

Before craniofacial repair and through 1 year of age, none of the studied parameters differed for FOA versus ESC treated patients. Palpebral fissure downslanting became statistically greater for those treated by FOA by 3 (P < 0.001) and 5 years of age (P = 0.001). Likewise, severity of palpebral fissure downslanting correlated with severity of V-pattern strabismus at 3 (P = 0.004) and 5 (P = 0.002) years of age. Palpebral fissure downslanting and rectus muscle excyclorotation were typically coexistent (P = 0.053). Secondary interventions to control ICP were required in four of 14 patients treated by ESC (primarily FOA) and in two of 11 patients initially treated by FOA (primarily third ventriculostomy) (P = 0.661).

Conclusions

Apert patients initially treated by ESC had less severe palpebral fissure downslanting and V-pattern strabismus, normalizing their appearance. Thirty percent initially treated by ESC required secondary FOA to control ICP.

Update in Management of Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the craniofacial dysmorphology of craniosynostosis, and the variation of each type. 2. Identify the functional concerns and learn the rationale behind timing of operative intervention. 3. Approach each dysmorphology critically and identify the operative intervention needed to improve form and function 4. Understand and address the specific issues related to syndromic craniosynostosis and be able to delineate management plan.

SUMMARY

Craniosynostosis is a condition in which premature fusion of one or more cranial sutures lead to abnormal head shape and growth restriction of the brain. Nonsyndromic craniosynostosis occurs in isolation, and usually involves a single suture, whereas syndromic craniosynostosis may involve multiple sutures and is associated with extracraniofacial findings. Although surgical management can be similar, the treatment plan must take into consideration issues specific to the syndromes. This article aims to provide a concise overview of the authors' current understanding regarding the presentation, treatment principle, surgical option, and debates in craniosynostosis.

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.

Orbital and Periorbital Dysmorphology in Untreated Pfeiffer Syndrome

BACKGROUND

Visual impairment secondary to orbital and periorbital dysmorphology is frequent in Pfeiffer syndrome patients. The etiopathogenesis of this aberrancy, however, remains unclear.

METHODS

Untreated Pfeiffer syndrome patients (n = 31) and normal control subjects (n = 43) were compared. Craniometric and volumetric analyses related to the orbital and periorbital anatomy were performed using Materialise (Leuven, Belgium) software.

RESULTS

Overall, orbital cavity volume of Pfeiffer patients is reduced by 28 percent (p < 0.001), compared to normal, starting before 3 months of age (p = 0.004). Globe volume was diminished by 10 percent (p = 0.041) before 3 months of age, yet tended to catch up thereafter. However, the retrobulbar soft-tissue volume remained smaller beyond 1 year of age (17 percent, p = 0.003). Globe volume projection beyond the bony orbit increased in all observed ages (82 percent, p < 0.001). The volumes of sphenoid bone, maxilla, and mandible proportionately were restricted by 24 to 25 percent (p = 0.003 to 0.035) before 3 months of age. The volume of maxilla and mandible gradually approximate normal; however, the sphenoid bone volume in Pfeiffer patients remains less than normal (p = 0.002) into childhood. The anteroposterior length of both the zygoma and the maxilla was reduced by 14 percent (p < 0.001). Anterior positioning of the zygoma is less by 23 percent (p < 0.001) in Pfeiffer patients overall, with anterior positioning of maxilla reduced similarly by 23 percent (p < 0.001).

CONCLUSIONS

Pfeiffer syndrome patients develop decreased retrobulbar soft-tissue and globe volume, along with a restricted orbital cavity volume in infancy. Significant hypoplasia of the sphenoid bone is associated with more severe central facial (maxilla) retrusion, compared to lateral facial structures (zygoma).

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Does different cranial suture synostosis influence orbit volume and morphology in Apert syndrome?

This study was performed to compare the orbital and peri-orbital morphological variations in Apert syndrome patients with different cranial vault suture synostosis, so as to provide an anatomic basis for individualized surgical planning. Computed tomography scans of 57 unoperated Apert syndrome patients and 59 controls were subgrouped as follows: type I, bilateral coronal synostosis; type II, pansynostosis; type III, perpendicular combinations of cranial vault suture synostoses. Orbit bony cavity volume was significantly reduced in type I and type II, by 19% (P < 0.001) and 24% (P < 0.001), respectively. However, the reduction of orbital cavity volume in type III did not reach statistical significance. Globe volume projection beyond the orbital rim, however, increased by 76% (P < 0.001) in type III, versus an increase of 54% (P < 0.001) in type I and 53% (P < 0.001) in type II, due to different ethmoid and sphenoid bone malformations. Maxillary bone volume was only significantly reduced in type I bicoronal synostosis (by 24%, P = 0.048). Both type I and type II developed relatively less zygoma and sphenoid bone volume. Different cranial vault suture synostoses have varied influence on peri-orbital development in Apert syndrome. Instead of mitigating the abnormalities resulting from bicoronal synostosis in type I, additional midline suture synostosis worsens the exorbitism due to a more misshaped ethmoid.

Computer tomography-based quantitative analysis of the orbital proptosis severity in infants with syndromic craniosynostosis: case-control study

PURPOSE

Evaluation of orbital proptosis and sutural synostosis pattern along the coronal ring in craniofaciosynostosis patients with or without fibroblastic growth factor receptor 2 (FGFR2) mutation.

METHODS

High-resolution computer tomography was used to assess, in children with or without FGFR2 mutation, the early synostotic involvement of the "major" and "minor" sutures/synchondroses of the coronal arch along with the following orbital parameters: interorbital angle, bone orbital cavity volume, globe volume, ventral globe volume, ventral globe index.

RESULTS

Infants with FGFR2 mutation showed an increased number of closed minor sutures/synchondroses along the posterior coronal branch while both groups showed a comparable synostotic involvement of the minor sutures of the anterior coronal branch. FGFR2 infants with posterior coronal branch synostotic involvement showed a higher degree of proptosis due to both reduced bony cavity volume and increased globe volume (p<0.05).

CONCLUSIONS

Our data show that FGFR2 mutation together with posterior coronal branch synostotic involvement has a synergic effect in causing a more severe degree of orbital proptosis.

Racial disparity in orbital morphology and spatial relations in unoperated Crouzon patients

The altered orbital morphology of patients with Crouzon syndrome could have an impact on the planning of treatment in diverse populations, in spite of the confounding influences of different cranial suture synostosis. This study attempted to explore the differences in orbital characteristics between Asian, Caucasian patients with Crouzon syndrome, associated pansynostosis. Eighty-six preoperative computed tomograms (CT) were included (Asian Crouzon syndrome: n=10; Asian controls: n=24; Caucasian Crouzon syndrome: n=19; Caucasian controls: n=33) and measured using Mimics software (Materialise). Unique cephalometric measurements related to orbital morphology and position were designed. Crouzon syndrome and race both have interactive effects on protrusion of the globe (p=0.009) and medial horizontal angle (p=0.012) in the assessment of orbital morphology. They also interact in the width of the ethmoid sinus (p=0.009) and influence bilateral orbital relations. The anteroposterior orbital roof in Caucasian patients with Crouzon syndrome was shortened by 4.09mm (p=0.002) compared with Caucasian controls. However, in Asian patients this dimension developed normally. The anteroposterior orbital floor was significantly reduced to a similar extent in both Asian and Caucasian Crouzon patients (both p<0.001). The visual axes in Caucasian patients with Crouzon showed more inferior rotation, by 4.38° (p=0.031) than they did in Caucasian controls, but did not achieve a statistically significant difference in other comparisons. The effect of Crouzon syndrome on orbital malformation and placement is influenced by race, especially structures related to the ethmoid sinus. Asian patients need greater infraorbital advancement for better correction of orbital proptosis and aesthetic benefits, but may require less fronto-orbital advancement than Caucasian patients.

Evaluation of the changes of orbital cavity volume and shape after tooth-borne and bone-borne rapid maxillary expansion (RME)

Objective

To assess and compare volumetric and shape changes of the orbital cavity in patients treated with tooth-borne (TB) and bone-borne (BB) rapid maxillary expansion (RME).

Study design

Forty adolescents with bilateral maxillary cross-bite received tooth-borne (TB group = 20; mean age 14.27 ± 1.36 years) or bone-borne (BB group = 20; mean age of 14.62 ± 1.45 years) maxillary expander. Cone-beam computed tomography (CBCT) were taken before treatment (T1) and 6-month after the expander activation (T2). Volumetric and shape changes of orbital cavities were detected by referring to a specific 3D digital technology involving deviation analysis of T1/T2 CBCT-derived models of pulp chamber. Student’s t tests were used to 1) compare T1 and T2 volumes of orbital cavities in TB and BB groups, 2) compare volumetric changes and the percentage of matching of 3D orbital models (T1-T2) between the two groups.

Results

Both TB and BB groups showed a slight increase of the orbital volume (0.64 cm³ and 0.77 cm³) (p < 0.0001). This increment were significant between the two groups (p < 0.05) while no differences were found in the percentage of matching of T1/T2 orbital 3D models (p > 0.05). The areas of greater changes were detected in the proximity of the frontozygomatic and frontomaxillary sutures.

Conclusion

TB-RME and BB-RME would not seem to considerably affect the anatomy or the volume of the orbital cavity in adolescents.

Analysis of Airway and Midface in Crouzon Syndromes

BACKGROUND

Crouzon syndrome is associated with severe respiratory impairment of the upper airway due in part to midfacial dysmorphology. We calculated the distinctive nasal diameter and pharyngeal airway volume in patients with Crouzon syndrome and compared them with age-matched control subjects.

METHODS

Children with computed tomography scans in the absence of surgical intervention were included. Computed tomography scans were digitized and manipulated using Surgicase CMF (Materialise). Craniometric data relating to the midface and airway were collected. For all linear measurements, mean percent increases or decreases were calculated relative to the size of control subjects, and volumetric assessment of the airway was tabulated. Statistical analysis was performed using t test.

RESULTS

Twenty-six computed tomography scans were included (control n = 17, Crouzon n = 9). All children were in early mixed dentition. Pharyngeal airway volume was decreased in patients with Crouzon syndrome relative to control subjects by 46% (P = 0.003). The distance from the posterior tongue to the posterior pharyngeal wall decreased 31% when comparing the Crouzon group versus the control (P = 0.04).

CONCLUSIONS

Three-dimensional analysis revealed notably decreased pharyngeal and nasal airway volumes in patients with Crouzon syndrome, but nasal bone tissue and soft tissue measurements showed very little change between patients and control subjects.

Airway Analysis in Apert Syndrome

BACKGROUND

Apert syndrome is frequently combined with respiratory insufficiency, because of the midfacial deformity which, in turn, is influenced by the malformation of the skull base. Respiratory impairment resulting from Apert syndrome is caused by multilevel limitations in airway space. Therefore, this study evaluated the segmented nasopharyngeal and laryngopharyngeal anatomy to clarify subcranial anatomy in children with Apert syndrome and its relevance to clinical management.

METHODS

Twenty-seven patients (Apert syndrome, n = 10; control, n = 17) were included. All of the computed tomographic scans were obtained from the patients preoperatively, and no patient had confounding disease comorbidity. Computed tomographic scans were analyzed using Surgicase CMF. Craniometric data relating to the midface, airway, and subcranial structures were collected. Statistical significance was determined using t test analysis.

RESULTS

Although all of the nasal measurements were consistent with those of the controls, the nasion-to-posterior nasal spine, sphenethmoid-to-posterior nasal spine, sella-to-posterior nasal spine, and basion-to-posterior nasal spine distances were decreased 20 (p < 0.001), 23 (p = 0.001), 29 (p < 0.001), and 22 percent (p < 0.001), respectively. The distance between bilateral gonions and condylions was decreased 17 (p = 0.017) and 18 percent (p = 0.004), respectively. The pharyngeal airway volume was reduced by 40 percent (p = 0.01).

CONCLUSION

The airway compromise seen in patients with Apert syndrome is attributable more to the pharyngeal region than to the nasal cavity, with a gradually worsening trend from the anterior to the posterior airway, resulting in a significantly reduced volume in the hypopharynx.

Evaluation and Management of V pattern Strabismus in Craniosynostosis

V pattern strabismus is the most common ocular motor disorder reported in patients with craniosynostosis. Strabismus management may prove challenging, and few studies provide perspective on surgical approach. The purpose of this review is to discuss evaluation and surgical options for treating V pattern strabismus in patients with craniosynostosis. We provide a step-by-step approach to facilitate surgical planning.

The Postoperative Morphometrics of Orbital and Maxillary Area for Craniosynostosis

One of the most characteristic features in premature craniosynostosis is fronto-orbital retrusion. The standardized surgical technique of fronto-orbital advancement (FOA) can treat this (some) deformity, such as bilateral coronal synostosis. The purpose of the study is to investigate an available method to assess the postoperative outcome of the craniofacial surgery.

Syndromic Craniosynostosis

Management strategies for syndromic craniosynostosis patients require multidisciplinary subspecialty teams to provide optimal care for complex reconstructive approaches. The most common craniosynostosis syndromes include Apert (FGFR2), Crouzon (FGFR2), Muenke (FGFR3), Pfeiffer (FGFR1 and FGFR2), and Saethre-Chotzen (TWIST). Bicoronal craniosynostosis (turribrachycephaly) is most commonly associated with syndromic craniosynostosis. Disease presentation varies from mild sutural involvement to severe pansynostoses, with a spectrum of extracraniofacial dysmorphic manifestations. Understanding the multifaceted syndromic presentations while appreciating the panoply of variable presentations is central to delivering necessary individualized care. Cranial vault remodeling aims to relieve restriction of cranial development and elevated intracranial pressure and restore normal morphology.

Classification of Subtypes of Apert Syndrome, Based on the Type of Vault Suture Synostosis

Supplemental Digital Content is available in the text.

Background:

Apert syndrome patients are different in clinical pathology, including obstructive sleep apnea, cleft palate, and mental deficiency. These functional deficiencies may be due to anatomic deformities, which may be caused by different forms of associated suture fusion. Therefore, a classification system of Apert syndrome based on the type of craniosynostosis pattern might be helpful in determining treatment choices.

Methods:

CT scans of 31 unoperated Apert syndrome and 51 controls were included and subgrouped as: class I. Bilateral coronal synostosis; class II. Pansynostosis; and class III. Perpendicular combination synostosis: a. unilateral coronal and metopic synostosis; b. sagittal with bilateral/unilateral lambdoid synostosis; and c. others.

Results:

Class I is the most common (55%) subtype. The cranial base angulation of class I was normal; however, the cranial base angulation on the cranium side of the skull in class II increased 12.16 degrees (P = 0.006), whereas the facial side cranial base angle of class IIIa decreased 4.31 degrees (P = 0.035) over time. The external cranial base linear measurements of class I showed more evident reduction in anterior craniofacial structures than posterior, whereas other subtypes developed more severe shortening in the posterior aspects.

Conclusions:

Bicoronal synostosis is the most common subtype of Apert syndrome with the normalized cranial base angulation. Combined pansynostosis patients have flatter cranial base, whereas the combined unilateral coronal synostosis have a kyphotic cranial base. Class I has more significant nasopharyngeal airway compromise in a vertical direction, whereas classes II and III have more limited oropharyngeal space.

Spatial and temporal changes of midface in Apert's syndrome

The dysplastic maxilla and retracted zygoma characterize Apert's syndrome. The relationship between the cranial base and facial development is believed to be influential and substantial. The purpose of this study is to explore the temporal relationships of maldevelopment of these structures to identify potential influence patterns. Fifty-four CT scans (unoperated Apert's, n = 18; control, n = 36) were included and divided into three age subgroups (0-6 months, 6 months-2 years, and 2-6 years). All measurements were analyzed by Materialize software. Cephalometrics relating to midface and cranial base were collected. In anteroposterior direction, prior to 6 months, the zygoma was markedly retruded by 12% in Apert's, followed by persistent retrusive shape into adulthood, averaging 17% shorter compared to controls. The maxillary anteroposterior dimension was 22% shorter than normal before 6 months of age, thereafter, it maintained at least an 18% deficiency into adulthood. In the horizontal direction, the transverse width of the zygoma increased 39% between 6 months and 2 years of age, and it was 14% wider on average overall into adulthood. The maxilla had normal growth in transverse and vertical directions. The zygoma is the most severely deformed anatomic facial structure in early infancy, in both positional relation and geometric shape in Apert's syndrome. This may develop as a 'bridge', influencing the structure, transmitting malformation stresses, caused by premature fused coronal and peri-zygomatic sutures, into facial structures and the maxilla.

Facial Malformation in Crouzon's Syndrome Is Consistent with Cranial Base Development in Time and Space

Supplemental Digital Content is available in the text.

Background:

In Crouzon’s syndrome, cranial base deformities begin sequentially in the anterior cranial fossa initially, and later to the posterior cranial base. Facial characteristics are likely related to cranial base development. The temporal correlation between cranial base development and facial features is in need of clarification in Crouzon’s patients, to clarify initial sites of deformity, which may impact surgical decision making.

Methods:

Thirty-six computed tomography scans of unoperated Crouzon’s syndrome patients and 54 controls were included and divided into 5 age-subgroups. All the planes used for analysis were set as perpendicular to a defined “midplane” to offset the confounding factor caused by potential asymmetry.

Results:

The angle between Sella-Nasion plane and Frankfort horizontal plane was significantly increased before 6 months of age (P = 0.014), with an average 70% (P < 0.001) increase ultimately into adulthood. The angle between SN and maxillary plane and the angle between Sella-Nasion and occlusal planes increased consistently through infancy to adulthood (124% and 42%, respectively, both P < 0.001). The relative angle of mandibular plane to Frankfort horizontal plane increased before 6 months (28%, P = 0.007) with a peak timeframe from 2 to 18 years. Facial lateral curvature related measurements indicate the whole face is inclined posteriorly and inferiorly direction in relation to the anterior cranial base.

Conclusion:

Crouzon’s facial malformation development is synchronous and positionally correlational with cranial base deformity. It transmitted from orbit to mandible, with the most evident morphologic changes are in the orbit and midface.

Defining and Correcting Asymmetry in Isolated Unilateral Frontosphenoidal Synostosis: Differences in Orbital Shape, Facial Scoliosis, and Skullbase Twist Compared to Unilateral Coronal Synostosis

INTRODUCTION

Isolated frontosphenoidal synostosis (FS) is a rare cause of fronto-orbital plagiocephaly that can be challenging to distinguish from isolated unicoronal synostosis (UC). The purpose of this paper is to analyze differences in fronto-orbital dysmorphology between the 2 conditions, to describe approaches for surgical correction, and to report surgical outcomes between FS and UC patients in a casecontrol fashion.

METHODS

Patients treated for craniosynostosis over a 12-year period at our institution were retrospectively evaluated under institutional review board approval. Frontosphenoidal synostosis patients who underwent bilateral fronto-orbital correction of anterior plagiocephaly with minimum 2-year follow-up, adequate pre-, and minimum 2-year postoperative computed tomography scans were included in the case-control portion of the study. These patients were randomly age-matched to UC patients meeting the same inclusion criteria. Preoperative and postoperative orbital shape and volumetric analysis was performed using Mimics software.

RESULTS

Twelve FS patients were treated during the study period. Seven of these patients met casecontrol inclusion criteria with average follow-up of 47.5 months. The characteristic FS orbit was a relatively wide, short, and shallow trapezoid, while the characteristic UC orbit was a relatively narrow, tall, and deep parallelogram. Frontosphenoidal synostosis orbits were significantly wider, shorter, shallower, and smaller than UC orbits. Surgical correction tailored to the differential dysmorphologies resulted in statistical equalization of these differences between affected and contralateral control orbits at follow-up, with the exception of UC orbital width, which remained significantly narrower than unaffected contralateral control. One patient in each group required cranioplasty for skull defects at follow-up, while no patient underwent surgical readvancement.

CONCLUSIONS

Frontosphenoidal synostosis and UC orbital shape differ significantly, and can be normalized using fronto-orbital advancement tailored to the distinct orbital dysmorphologies of these 2 groups.