Bilateral Orbital Dysmorphology in Unicoronal Synostosis:

Non-syndromic craniosynostosis

Craniosynostosis is characterized by the premature fusion of one or more major cranial sutures at birth or soon after. Single-suture non-syndromic craniosynostosis (NSC) is the most common form of craniosynostosis and includes the sagittal, metopic, unicoronal and unilambdoid subtypes. Characterized by an abnormal head shape specific to the fused suture type, NSC can cause increased intracranial pressure. Cranial sutures either originate from the neural crest or arise from mesoderm-derived mesenchymal stem cells. A mixture of environmental and genetic factors contributes to NSC, with genetic causes following a largely polygenic model. Physical examination is used to identify the majority of patients, but accompanying radiographic imaging can be confirmatory. The three major surgical techniques in use to treat NSC are cranial vault remodelling, strip craniectomy and spring-assisted cranioplasty. Surgical intervention is ideally performed in the first year of life, with a mortality of <1%. Health-care disparities contribute to delayed initial presentation and timely repair. Optimal timing of surgery and comparative outcomes by surgical technique remain under active study. School-age children with treated NSC on average have subtle, but lower cognitive and behavioural performance. However, patient-reported quality of life outcomes are comparable to those in control individuals.

Understanding the heterogenicity of unicoronal synostosis - A morphometric analysis of cases compared to controls

BACKGROUND

Preoperative severity of unicoronal synostosis varies greatly and involves the frontal bone, skull base and orbits. Degree of deformity affects long-term morphological and functional outcomes after surgery. The aim of this study was to describe the morphological heterogenicity and investigate its relation to patient-specific factors.

MATERIALS AND METHODS

In this retrospective cohort study, non-syndromic unicoronal synostosis patients treated between 2006 and 2022 at Necker Hospital, France or Uppsala University Hospital, Sweden, were included and matched to controls. Severity of skull base, orbital and posterior skull asymmetry, degree of anterior plagiocephaly and Harlequin deformity, lateralisation, head circumference, age, timing of metopic fusion and fusion of peri-pterionic sutures were investigated.

RESULTS

Ninety-five patients and ninety-three controls were included. Skull base asymmetry was linearly related to orbital asymmetry (p < 0.001), correlated with earlier CT scans (p = 0.004) and anterior (p < 0.001) and posterior (p = 0.03) plagiocephaly. Posterior plagiocephaly was more common in patients (31%) compared with controls (5%) (p < 0.001). A patent metopic suture above nine months of age was associated with severe Harlequin deformity (p = 0.04) and a lower head circumference when fused (p = 0.03). Fronto-sphenoidal suture fusion was associated with later CT scans (p < 0.001) and less skull base asymmetry (p = 0.002). Spheno-parietal fusion was correlated with decreased skull base asymmetry (p = 0.03). Right lateralisation was more common in females.

CONCLUSIONS

Heterogenicity of unicoronal synostosis seems to be predominantly explained by variability in skull base morphology. Peri-pterionic fusions might limit deformity.

Impact of One-Piece Fronto-Orbital Distraction Osteogenesis on Orbital Morphology and Strabismus Development in Unilateral Craniosynostosis

BACKGROUND

Unicoronal craniosynostosis (UCS) is associated with orbital dysmorphologies that underlie ophthalmologic dysfunctions, such as strabismus. This study aimed to assess orbital dysmorphology in patients with UCS and how it changes after fronto-orbital distraction osteogenesis (FODO), and to analyze the features of new-onset strabismus.

METHODS

A retrospective analysis was conducted on 19 patients with UCS who underwent FODO between May of 2008 and November of 2020. Ophthalmologic records and computed tomographic scans were reviewed. Seven parameters, including width, height, volume, and four-direction orbital angles were evaluated in patients with UCS and compared with those of age-matched control subjects.

RESULTS

The superolateral angle and vertical angle of the ipsilateral orbit and the superomedial angle (SMA) of the contralateral orbit were more obtuse than those of the controls. Following FODO, the ipsilateral superolateral angle was decreased from 69.2 ± 5.4 degrees to 59.1 ± 4.2 degrees ( P = 0.001), and the contralateral SMA was decreased from 64.8 ± 5.8 degrees to 60.2 ± 6.0 degrees ( P = 0.003). Four of the 17 patients without strabismus in the preoperative period developed strabismus, and the horizontal type was the most common. Logistic regression analysis demonstrated a significant association between new-onset strabismus and SMA difference between both orbits (OR, 1.39; P = 0.041).

CONCLUSIONS

Orbital dysmorphology in the UCS is bilateral, and the orbital roofs are dysmorphic. The bilateral orbital roofs are lifted toward the fused coronal suture and can be improved after FODO. Horizontal strabismus, such as esotropia and exotropia, is common after FODO, and superomedial orbital roof asymmetry may play a role in its development.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Nasal monobloc osteotomy for correction of late nasal and orbital asymmetry of unicoronal synostosis: A morphometric and outcomes study

BACKGROUND

Craniofacial asymmetry associated with unicoronal synostosis (UCS) may persist into the teenage years despite surgery in infancy. This study evaluated outcomes following a nasal monobloc procedure by mobilizing a united nasomaxillary and bilateral medial orbital segment of bone (nasal monobloc) to perform corrective translational and rotational movement for secondary correction of residual nasal-orbital asymmetry associated with UCS.

METHODS

A retrospective review of all UCS patients treated with nasal monobloc at our institution was performed. Demographic information was recorded, and pre- and postoperative 2D imaging was used for morphometric outcome analysis. Outcomes and complications were tabulated.

RESULTS

The study included 14 patients (5 males, 9 females; mean age 14.6 years; range 9.6 to 22.5 years; mean follow-up 70.6 months range 12 to 132 months). Ancillary procedures (scar revision, forehead/orbital contouring, MEDPOR® augmentation) were performed in all patients at the time of the nasal monobloc. One patient underwent a repeat procedure 6 years later following technique modification. Additionally, another patient experienced late overgrowth of the frontal sinus with forehead asymmetry. The morphometric analysis demonstrated significant (p < 0.05) pre-op to post-op improvements in naso-orbital asymmetry, as demonstrated by horizontal orbital aperture ratio (0.88 vs 0.99), midline to exocanthion ratio (0.91 vs 0.98), orbital index ratio (1.15 vs 1.01), and midline discrepancy (7.1 degrees vs 2.7 degrees).

CONCLUSION

Nasal monobloc osteotomy provides a reasonable surgical treatment to improve both the nasal and orbital asymmetries associated with unicoronal synostosis, including frontal nasal deviation, basal nasal deviation, and orbital aperture asymmetry. It is important to note that confounding anatomic variables such as globe dystopia, strabismus, and scleral show may affect the perception of orbital symmetry.

The influence of orbital architecture on strabismus in craniosynostosis

PURPOSE

To better characterize the correlation of bony orbital dysmorphology with strabismus in craniosynostosis.

METHODS

The medical records of patients with craniosynostosis with and without strabismus seen at Rady Children's Hospital (San Diego, CA) from March 2020 to January 2022 were reviewed retrospectively in this masked, case-control study. Computed tomography scans of the orbits were analyzed to obtain dimensions of the orbital entrance and orbital cone. Primary outcome was correlation of strabismus with orbital measurements.

RESULTS

A total of 30 orbits from 15 patients with strabismus and 15 controls were included. Craniofacial disorders included in the study were nonsyndromic craniosynostosis (63%), Crouzon syndrome (13%), Apert syndrome (13%), and Pfeiffer syndrome (10%). Orbital index (height:width ratio) (P = 0.01) and medial orbital wall angle (P = 0.04) were found to differ significantly between the strabismus and control groups.

CONCLUSIONS

In our small cohort, bony orbital dimensions, including the ratio of orbital height to width and bowing of the medial orbital wall, were associated with strabismus in craniosynostosis.

Ophthalmic Manifestations of Unilateral Coronal Synostosis

PURPOSE

To summarize the ophthalmic manifestations of unilateral coronal synostosis patients.

METHODS

We performed a literature search in the electronic database of PubMed, CENTRAL, Cochrane, and Ovid Medline guided by Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement for studies evaluating ophthalmic manifestations of unilateral coronal synostosis.

RESULTS

Unilateral coronal synostosis, also called unicoronal synostosis, may be mistaken for deformational plagiocephaly, an asymmetric skull flattening common in newborns. Characteristic facial features, however, distinguish the two. Ophthalmic manifestations of unilateral coronal synostosis include a "harlequin deformity", anisometropic astigmatism, strabismus, amblyopia, and significant orbital asymmetry. The astigmatism is greater on the side opposite the fused coronal suture. Optic neuropathy is uncommon unless unilateral coronal synostosis accompanies more complex multi-suture craniosynostosis. In many cases, surgical intervention is recommended; without intervention, skull asymmetry and ophthalmic disorders tend to worsen with time. Unilateral coronal synostosis can be managed by early endoscopic stripping of the fused suture and helmeting through a year of age or by fronto-orbital-advancement at approximately 1 year of age. Several studies have demonstrated that anisometropic astigmatism, amblyopia, and severity of strabismus are significantly lower after earlier intervention with endoscopic strip craniectomy and helmeting compared to treatment by fronto-orbital-advancement. It remains unknown whether the earlier timing or the nature of the procedure is responsible for the improved outcomes. As endoscopic strip craniectomy can only be performed in the first few months of life, early recognition of the facial, orbital, eyelid, and ophthalmic characteristics by consultant ophthalmologists enables expeditious referral and optimized ophthalmic outcomes.

CONCLUSION

Timely identification of craniofacial and ophthalmic manifestations of infants with unilateral coronal synostosis is important. Early recognition and prompt endoscopic treatment appears to optimize ocular outcomes.

Pre-Operative Ocular Findings and Long-Term Follow-Up in a Large Cohort of Non-Syndromic Unicoronal Craniosynostosis

(1) Background: Non-syndromic unicoronal craniosynostosis (UCS) is associated with a high prevalence of ocular anomalies. Currently, the etiology of this association remains obscure, however, it is presumed to be primarily attributed to their orbital malformations and/or secondary to craniofacial surgery. We assessed pre-operative ophthalmological examinations of non-syndromic UCS patients and compared them with their postoperative outcomes and long-term follow-up. (2) Methods: A retrospective case series was conducted on medical records of patients with non-syndromic UCS at Sophia Children's Hospital, Rotterdam. Ophthalmologic examinations were collected at different time periods: T1 (first visit), T2 (<1 year after cranioplasty), and T3 (long-term follow-up at last visit). The McNemar's test was used for statistical analysis. (3) Results: A total of 101 patients were included, for whom examinations were available at T1 and T3. Patients had a mean age of 2.8 years (±2.7) and 9.5 (±4.9) at T1 and T3, respectively. At T1, 52 patients (51.5%) were diagnosed with strabismus, and 61 patients (60.4%) at T3. Vertical strabismus increased significantly from 23 patients (22.8%) at T1 to 36 patients (35.6%) at T3 (p = 0.011). Followed by astigmatism, which increased significantly from 38 (37.6%) at T1 to 59 (58.4%) patients at T3 (p = 0.001). T1 was available in 20 patients prior to fronto-orbital advancement (FOA), therefore, a sub-analysis was conducted on these patients, which was followed shortly after FOA at T2. Prior to FOA, strabismus was present in 11 patients (55.0%) and in 12 patients (60.0%) at T2. After FOA, strabismus worsened in two patients. (4) Conclusions: This study showed the high prevalence of ocular anomalies in patients with non-syndromic UCS before and after cranioplasty and at long-term follow-up. The findings of this study show that ophthalmic and orthoptic examinations are an important part of the optimal treatment of patients with non-syndromic UCS.

Torticollis in Non-Syndromic Unicoronal Craniosynostosis Is Predominantly Ocular Related

(1) Background: Patients with unicoronal craniosynostosis (UCS) often show torticollis which can result from either an ocular cause or contraction of the sternocleidomastoid muscle. For clinicians, it is crucial to know the prevalence of ocular torticollis (OT) to ensure appropriate referral for treatment. Furthermore, associated ophthalmic features with OT in these patients are scarcely described. The aim of this study was to determine the prevalence of OT in non-syndromic UCS patients and investigate its associated ophthalmic features. (2) Methods: In this descriptive cross-sectional study medical records of non-syndromic UCS patients treated between 1994-2022 in one tertiary care hospital in The Netherlands were retrospectively reviewed. Collected data included: diagnosis and type of torticollis, binocular single vision (BSV), strabismus, ocular motility, alphabetical patterns, refractive error, and amblyopia. Patients were classified as OT, based on their ophthalmic and/or orthoptic diagnosis. Prevalence was determined with the 95% CI using the Clopper-Pearson exact test. Associations between OT and the ophthalmic features were determined using Chi-square or Fishers' exact test and its effect size was calculated using Cramer's V. (3) Results: In total, 146 patients were included, of whom 57 had torticollis. An ocular cause for the torticollis was found in 54 patients. The prevalence of OT was 37% (n = 146; 95% CI [0.292-0.454]). Significant associations were found between OT and strabismus (p < 0.001), ocular motility abnormalities (p < 0.001), alphabetical patterns (p < 0.001), and amblyopia (p = 0.002). BSV (p = 0.277) and refractive error (p = 1.0) were not significantly associated with OT. However, in OT the BSV was relatively poor (42.1%) and more frequently absent (26.3%) compared to the non-torticollis group (7% poor and 16.3% absent). In both groups, excyclotorsion was predominantly present (62.3%). (4) Conclusions: In 95% of cases, torticollis in UCS patients is ocular-related. Overall, one in three patients with UCS have OT. This study emphasizes the importance of a timely referral of all patients with UCS with torticollis to an orthoptist and/or ophthalmologist, specialized in diagnosing and treatment of OT, before considering physiotherapy.

3-Dimensional Morphometric Outcomes After Endoscopic Strip Craniectomy for Unicoronal Synostosis

BACKGROUND

Endoscopic strip craniectomy with postoperative helmeting (ESCH) for unicoronal synostosis has shown to be a less morbid procedure when compared with fronto-orbital remodeling (FOR). We aim in this pilot study to report objective methods and quantitative morphologic outcomes of endoscopically treated unicoronal synostosis using 3-dimensional surface scans.

METHODS

Our electronic records were reviewed for ophthalmological, neurodevelopmental outcomes, and helmet-related complications. For morphologic outcomes, the following parameters were used: Cranial Index, Cranial Vault Asymmetry Index, Anterior Symmetry Ratio (ASR), and Root Mean Square between the normal and synostotic sides of the head. Three-dimensional stereophotogrammetry scans were evaluated at 3 time points preoperative, 6 months post-op, and at the end of the treatment, which was compared with age-matched scans of normal controls and FOR patients. Nonparametric tests were used for statistical analysis.

RESULTS

None of the ESCH cases developed strabismus, major neurodevelopmental delay, or helmet complications. All morphologic parameters improved significantly at 6 months post-op except for the Cranial Vault Asymmetry Index. The ASR was the only parameter to change significantly between 6 months post-op and final scans. At end of helmet treatment, ASR and Root Mean Square differed significantly between the ESCH and both FOR and control groups.

CONCLUSIONS

Endoscopic strip craniectomy with postoperative helmeting for single unicoronal synostosis had excellent clinical outcomes. Most of the improvement in head morphology occurred in the first 6 months of treatment. Despite the normalization of the overall head shape, there was residual asymmetry in the frontal and temporal regions of the head.

Anterior Synostotic Plagiocephaly: A Quantitative Analysis of Craniofacial Features Using Computed Tomography

The premature fusion of one coronal suture causes anterior synostotic plagiocephaly (ASP), which results in overt craniofacial dysmorphology that could be challenging to correct. This study aimed to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (nonsynostotic) sides in a select cohort of South African patients with ASP, using computed tomography (CT) scans. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on 2-dimensional CT scans of 18 consecutive patients diagnosed with nonsyndromic ASP. The differences between the ipsilateral and contralateral sides were calculated and expressed as a percentage of the contralateral side. All ACF parameters decreased significantly on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (-27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim, height, and surface area parameters increased significantly, with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim, breadth and volume) decreased significantly, with the length-supraorbital rim parameter being the most affected (-10.8%). The ipsilateral ear was found to be displaced anteriorly (9.33 mm) and caudally (5.87 mm) from the contralateral ear. These measures may be useful to surgeons during corrective surgery by indicating the degree of the asymmetry on each side, making it easier to plan the technique and extent of surgical correction of the affected structures.

Objective Analysis of Fronto-Orbital Dysmorphology in Unilateral Coronal Craniosynostosis

ABSTRACT

Correction (and over-correction) of asymmetries of the orbital shape and brow position in unilateral coronal craniosynostosis (UCS) is critical to successful fronto-orbital advancement. Here we quantify and three-dimensionally assess fronto-orbital irregularities in UCS patients compared to controls.Twenty-three patients with UCS evaluated at the Children's Hospital of Pittsburgh between 2006 and 2016 were age and gender-matched to controls. Computed tomography scans were reconstructed and evaluated for orbital metrics. A three-dimensional heat map of orbital regions was generated and evaluated for shape differences.Brow protrusion of the orbit ipsilateral to the synostotic suture did not differ significantly from healthy controls. Orbital height was significantly increased while orbital width was decreased on the UCS ipsilateral side compared to the contralateral side and controls. The ipsilateral cornea was overprojected relative to the brow and the infraorbital rim, but similar to controls relative to the lateral rim. The contralateral orbit had increased brow protrusion with decreased orbital height. The cornea was underprojected relative to the brow, but overprojected relative to the lateral orbital rim and similar to controls at the infraorbital rim. Three-dimensional comparison demonstrated significant overprojection of the contralateral brow, with some more mild and inconsistent underprojection of the lateral aspect of the ipsilateral brow.Key orbital and brow differences exist between the affected and unaffected sides in UCS. This study provides quantitative data that further characterize the orbital dysmorphology observed in UCS and identifies unique aspects of the diagnosis that should be taken into consideration during surgical planning.

Orbital Volumetric Analysis in Patients With Unicoronal Craniosynostosis: A Comparison Between Distraction Osteogenesis and Fronto-Orbital Advancement

BACKGROUND

Unicoronal craniosynostosis is associated with orbital restriction and asymmetry. Surgical treatment aims to both correct the aesthetic deformity and prevent the development of ocular dysfunction. We used orbital quadrant and hemispheric volumetric analysis to assess orbital restriction and compare the effectiveness of distraction osteogenesis with anterior rotational cranial flap (DO) and bilateral fronto-orbital advancement and cranial vault remodeling (FOAR) with respect to the correction of orbital restriction in patients with unicoronal craniosynostosis.

METHODS

A retrospective review of all patients with a diagnosis of unicoronal craniosynostosis and treated with either DO or FOAR from 2000 to 2019 was performed. Preoperative and postoperative total orbital volumes, as well as quadrant and hemispheric volume ratios, were calculated from 3-dimensional head computed tomography scans. Selected preoperative and postoperative orbital measurements, including the maxillary length of the orbit (MLO; zygomaticofrontal suture to the top of zygomatic arch) and the sphenoid length of the orbit (SLO; the top of sphenoid suture to the top of zygomatic arch), were also obtained.

RESULTS

Data were available for 28 patients with unicoronal craniosynostosis. Mean preoperative total orbital volume was significantly smaller on the synostotic side compared with the nonsynostotic side (10.94 vs 12.20 cm3, P = 0.04). Preoperative MLO and SLO were significantly longer on the synostotic side compared with the nonsynostotic side (MLO: 20.26 vs 17.75 mm, P < 0.001; SLO: 26.91 vs 24.93 mm, P = 0.01). Distraction osteogenesis and FOAR produced significantly different changes in orbital quadrant and/or hemispheric volume ratios on the nonsynostotic side but not on the synostotic side.

CONCLUSIONS

Before correction, patients with unicoronal craniosynostosis have significantly smaller total orbital volumes on the synostotic side compared with the nonsynostotic side and significantly greater MLO and SLO on the synostotic side compared with the nonsynostotic side. There is no significant difference between DO and FOAR with regard to correcting the observed orbital restriction in these patients.

Orbital volume, ophthalmic sequelae and severity in unilateral coronal synostosis

PURPOSE

Unilateral coronal synostosis (UCS) results in an asymmetrical skull, including shallow and asymmetrical orbits, associated with reduced orbital volume and high prevalences of ophthalmic sequelae. Aim is to link orbital volumes in patients with UCS to severity according to UCSQ (Utrecht Cranial Shape Quantifier) and presence of ophthalmic sequelae.

METHODS

We included preoperative patients with UCS (≤ 18 months). Orbital volume was measured on CT scans by manual segmentation (Mimics software (Materialise, Leuven, Belgium)), and severity of UCS was determined by UCSQ. Orbital volume of affected side was compared to unaffected side using Wilcoxon signed rank test. Orbital volume ratio was calculated (affected/unaffected volume) and compared to the category of UCSQ by Kruskal-Wallis test. Opthalmic sequelae were noted.

RESULTS

We included 19 patients (mean age 7 months). Orbital volume on affected side was significantly lower (p = 0.001), mean orbital volume ratio was 0.93 (SD 0.03). No significant differences in group means of orbital volume ratio between different levels of severity of UCSQ were found (Kruskal-Wallis H (2) = 0.873; p > 0.05). Ophthalmic sequelae were found in 3 patients; one had adduction impairment and strabismus (mild UCS), one had astigmatism (moderate UCS), and one had abduction impairment (on both ipsi- and contralateral side) and vertical strabismus (severe UCS).

CONCLUSION

No association between orbital volume ratio and severity of UCS was found. Side-to-side asymmetry in orbital volume was noted. No association between either preoperative orbital volume ratio or severity of UCS and the presence of preoperative ophthalmic sequelae was found.

Ophthalmological outcomes of unilateral coronal synostosis in young children

BACKGROUND

To report refractive outcomes, describe types of strabismus and evaluate the outcomes of surgical intervention for unilateral coronal synostosis (UCS) in paediatric patients.

METHODS

This study retrospectively included 30 UCS cases. Patients aged from 3 months to 6 years (median: 1.8 years) were enrolled from January 2018 to December 2019 at Shanghai Children's Hospital. Sixteen patients had all types of strabismus; 15 of these patients underwent surgery.

RESULTS

Refractive errors of 30 cases were included. In 60% of patients, astigmatism of 1.00D or more existed in not less than one eye at last record. Twenty (66.7%) patients had the larger amount of astigmatism in the contralateral eye. Fifteen patients received strabismus surgery, of whom 6 patients with monocular elevation deficiency (MED) underwent the standard Knapp procedure, with or without a horizontal deviation procedure. Fifteen cases were horizontally aligned within 5 prism dioptres (Δ). Six patients with MED (100%) had attained ≥25% elevation improvement after surgery, and the vertical deviation decreased from 25.83 Δ ± 4.92 Δ (range, 20 Δ-30 Δ) to 0.83 Δ ± 4.92 Δ after surgery (range, 0 Δ-10 Δ), for an improvement of 26.67 Δ ± 4.08 Δ (t = 16 P < 0.05). In 1 patient with esotropia, the horizontal deviation decreased from + 80 Δ to + 5 Δ after surgery. One patient was diagnosed with trichiasis and one with contralateral lacrimal duct obstruction.

CONCLUSIONS

Contralateral MED was also the main type of strabismus in UCS. Superior oblique muscle palsy was still the most common, as previously reported. There is a risk of developing a higher astigmatism and anisometropia in the contralateral eye to synostosis. Other ophthalmic disorders should be treated in a timely manner.

TRIAL REGISTRATION

The study was approved by the Institutional Review Board of Shanghai Children's Hospital (approval No. 2020R023-E01) and adhered to the tenets of the Declaration of Helsinki. Ethics approval was procured on March 30, 2020. This was a retrospective study. Written informed consent was sought from the patients' parents or legal guardians. Clinical Trials Registry number: ChiCTR2000034910 . Registration URL: http://www.chictr.org.cn/showproj.aspx?proj=56726 .

Test-retest validation of a cranial deformity index in unilateral coronal craniosynostosis

Unilateral coronal craniosynostosis (UCS) affects many infants resulting in abnormalities affecting the forehead and orbits. As a result, the deformity caused by UCS is very noticeable and there are several surgical treatment options available to normalize the head shape. However, there is a lack of consistently used outcome measures, resulting in difficulty assessing surgical outcomes and on-going debate over optimal treatments. Current techniques to quantify deformity in UCS are cumbersome, provide limited information, or are based on subjective assessments. In this study, a cranial deformity index was developed to quantify abnormality at the frontal bones for UCS that is accessible, user-friendly, and generates objective surface distance measurements. The cranial deformity index is defined as the Euclidean distance at the point of the largest deviation between the deformed skull compared to a reference skull. In addition, the index was successfully used to quantify post-operative changes in a single case of UCS that underwent corrective surgery. The reproducibility of the index was assessed using test-retest reliability and was demonstrated to be highly reproducible (ICC = 0.93). A user-friendly measurement index that is based on open-source software may be a valuable tool for surgical teams. In addition, this information can augment the consultation experience for patients and their families.

3D printing guided surgery in the treatment of unicoronal craniosynostosis orbital dysmorphology

PURPOSE

The purpose of our study was to improve the minor asymmetries of fronto-orbital advancement (FOA) by introducing a simple model to guide the FOA in unicoronal synostosis which may help saving time and cost.

METHODS

A retrospective analysis of 16 consecutive patients with unicoronal synostosis corrected by FOA guided by a guide model. Patients with syndromic craniosynostosis or associated craniofacial anomalies were excluded from the analysis. In all cases, 3D mirror image models were used for guiding unilateral fronto-orbital advancement. Demographic, perioperative, and follow-up data were collected for comparison. Cranial and orbital volumes were documented preoperatively and postoperatively and compared with the non-synostotic side. The postsurgical appearance of the face was documented photographically and then evaluated and scored using the Whitaker scoring system.

RESULTS

The study included nine males and seven females. The mean age of the patients at the time of the operation was 20.4 months. The mean follow-up duration was 36 months. Mean operative time was 170 min, mean anesthetic time was 230 min, mean blood loss was 50-80 ml, and the average hospital stay was 4.4 days. No relapse that required surgical correction was reported. There were improvements in the orbital indices and volume to be near equal to the normal side. Excellent to good results were obtained in all patients according to the Whitaker classification system.

CONCLUSION

Residual deformity after FOA mandates another tool to optimize the results. Our study introduced a simple, easy, and applicable method to guide the FOA with lesser asymmetries.

Cranioorbital Morphology Caused by Coronal Ring Suture Synostosis

BACKGROUND

Minor cranial sutural synostosis is currently regarded as a rare diagnosis. As clinical awareness grows, a greater number of cases are being documented. This study aims to describe the variants of unicoronal synostosis with regard to major and minor sutural involvement and secondary effects on cranial and orbital morphology. The information is aimed to improve clinical diagnosis and management.

METHODS

A retrospective study was conducted collecting preoperative computed tomographic scans of patients diagnosed with unicoronal synostosis and listed for surgical interventions, identified from a craniofacial database. Within these patients, different synostotic variants were identified based on which suture was affected. Scans of normal pediatric skulls (trauma) were used for a control group. Computed tomographic scans were analyzed for sutural involvement, cranial base deflection, and ipsilateral and contralateral orbital height and width. One-way analysis of variance was used to detect differences between synostotic variants and controls.

RESULTS

A total of 57 preoperative computed tomographic scans of patients with unicoronal synostosis were reviewed, in addition to 18 computed tomographic scans of normal skulls (control group). Four variants of unicoronal synostosis were identified: frontoparietal, frontosphenoidal, frontoparietal and frontosphenoidal, and frontosphenoidal and frontoparietal. The last two variants differ in their temporal involvement in the direction of sutural synostosis and ultimately cranial and orbital morphology. Three variants have been previously identified, but the fourth is presented for the first time.

CONCLUSIONS

An understanding of the variants of unicoronal synostosis and their temporal relationships is integral for accurate clinical diagnosis and surgical correction. Recommendations for treatment are based on discrete changes in orbital morphology.

Strabismus in Unicoronal Craniosynostosis: Effect of Orbital Dysmorphology and Fronto-Orbital Advancement and Remodeling

BACKGROUND

The purpose of this study was to determine what craniometric changes occur to both orbits of unicoronal craniosynostosis patients undergoing fronto-orbital advancement and remodeling, and which of these changes are associated with new onset of postoperative strabismus.

METHODS

A retrospective analysis was performed of the preoperative and postoperative orbits of 24 unicoronal craniosynostosis patients and the orbits of 24 control subjects, totaling 144 orbits. Eight parameters were evaluated using multivariate logistic regression analysis. One of the parameters was modified orbital index, an indicator of severity of harlequin deformity.

RESULTS

Significant differences in orbital dimensions and angles were present bilaterally in unicoronal craniosynostosis orbits when compared to controls. Fronto-orbital advancement and remodeling increased the ipsilateral unicoronal craniosynostosis orbital volume from 13,184 ± 2003 mm to 16,220 ± 2323 mm (p < 0.001). Ipsilateral horizontal cone angles were increased from 48 ± 5 degrees to 54 ± 7 degrees (p = 0.004). Ipsilateral vertical cone angles were decreased from 73 ± 8 degrees to 66 ± 10 degrees (p = 0.003). Ipsilateral modified orbital index improved from 0.83 ± 0.06 to 0.88 ± 0.06 (p = 0.003). Three of the 19 unicoronal craniosynostosis patients developed transient postoperative strabismus. Logistic regression analysis displayed a strong significant association between new-onset strabismus and a change in modified orbital index with a coefficient of 30.84 ± 14.51 (p < 0.05).

CONCLUSIONS

The orbital dysmorphology in unicoronal craniosynostosis is bilateral in nature, and it is not wholly treated with conventional fronto-orbital advancement and remodeling. The severity of ipsilateral orbital dysmorphology is correlated with the incidence of postoperative strabismus following conventional fronto-orbital advancement and remodeling. Future research is needed to develop strategies to mitigate the risk of development of strabismus in this group of patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Age at Craniosynostosis Surgery and Its Impact on Ophthalmologic Diagnoses: A Single-Center Retrospective Review

BACKGROUND

Ocular abnormalities in craniosynostosis are a persistent concern for patients and providers, and some surgeons feel that early surgical intervention for synostosis alleviates the progression of ophthalmologic abnormalities. In contradistinction, the authors hypothesize that operating early will have no bearing on postoperative ophthalmologic outcomes.

METHODS

Single-suture craniosynostosis patients who underwent surgical correction between 1989 and 2015 were reviewed. Patients with multisuture craniosynostosis, syndromic diagnoses, no preoperative ophthalmology evaluation, and less than 2 years of follow-up were excluded. Logistic regression was used to determine odds of preoperative and postoperative ophthalmologic abnormalities by age, while controlling for patient-level covariates.

RESULTS

One hundred seventy-two patients met inclusion criteria. The median age at surgery was 10 months (interquartile range, 7 to 12.9 months). Increasing age at the time of surgery was associated with increased odds of preoperative ophthalmologic diagnoses (OR, 1.06; p = 0.037) but not postoperative diagnoses (OR, 1.00; p = 0.91). Increasing age at surgery was also not associated with increased odds of ophthalmologic diagnoses, regardless of timing (OR, 1.04; p = 0.08). Patients with coronal synostosis (OR, 3.94; p = 0.036) had significantly higher odds of preoperative ophthalmologic diagnoses. Patients with metopic (OR, 5.60; p < 0.001) and coronal (OR, 7.13; p < 0.001) synostosis had significantly higher odds of postoperative ophthalmologic diagnoses.

CONCLUSIONS

After reviewing an expansive cohort, associations of both overall and postoperative ophthalmologic diagnoses with age at surgery were not found. The authors' findings thus run counter to the theory that early surgical intervention lessens the likelihood of postoperative ophthalmologic diagnoses and improves ophthalmologic outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Periocular Asymmetry in Infants with Deformational Posterior Plagiocephaly

PURPOSE

To analyze the clinical significance of the periorbital features associated with the facial asymmetry that is common in deformational posterior plagiocephaly (DPP).

PATIENTS AND METHODS

We identified 32 patients with DPP, photographed their faces and tops of their head, and performed a complete eye examination. Four examiners analyzed the patient's periorbital features on the photographs.

RESULTS

Median age was 6.5 months (range 3-12 months). Pseudoptosis was identified in 30 patients and pseudo-brow ptosis in 19. Pseudoptosis was marked in 17 patients. Five patients were misdiagnosed with congenital blepharoptosis and received regular follow-ups for amblyopia checks until the diagnosis of pseudoptosis was established. All patients had normal levator function and symmetric eyelid crease. One patient with pseudoptosis and physiologic anisocoria was diagnosed with pseudo-Horner syndrome after a negative 10% cocaine test. None of the patients developed meridional or occlusion amblyopia.

CONCLUSION

DPP is the most frequent form of skull deformation in infants. Its main features are occipital flatness and facial asymmetry. Infants with DPP may present with pseudoptosis and pseudo-brow ptosis on the contralateral side of the occipital flatness. The pseudoptosis in DPP is non-amblyogenic, therefore, ophthalmologic intervention and regular follow-ups are not necessary unless other abnormalities co-exist.

Spatially Detailed 3D Quantification of Improved Facial Symmetry After Surgery in Children With Unicoronal Synostosis

OBJECTIVE

To assess improvement of soft-tissue facial symmetry in children surgically treated for unicoronal synostosis (UCS) in infancy, to correlate pre- and postsurgical facial asymmetry and to evaluate whether the improvement was visually recognizable.

DESIGN

Case-controlled follow-up.

PATIENTS/SETTINGS

Eleven Danish children diagnosed with UCS were included, 3 of whom had tested positive for Muenke mutation. Preoperative computed tomography scans and postoperative 3dMD surfaces were available for measurements. A control group of healthy children matched for age and sex was employed.

MAIN OUTCOME MEASURES

Pre- and postsurgical facial asymmetry was analyzed using a computerized method capable of objective and spatially detailed quantification in 3-dimension (transverse, vertical, and sagittal directions). Asymmetry was evaluated in the facial region and 6 subregions (forehead, mouth, eyes, nose, cheek, and chin).

RESULTS

The largest significant improvement was seen in the sagittal direction of the facial (1.9 mm), forehead (2.0 mm), and cheek (3.4 mm) regions. Small but significant improvements were also seen in the mouth, chin, and eye regions. No significant improvement was seen in the nose region. Significant correlations were found between the pre- and postsurgically calculated facial asymmetry and between calculated asymmetry and clinical validation scores.

CONCLUSIONS

All patients presented with improved facial symmetry after surgery and the improvements were visually recognizable. However, only 1 (9.1%) of the 11 patients reached a level of facial asymmetry as low as that seen in the control group. The best outcome was, in general, seen in cases with mild facial asymmetry presurgically.

Temporal Progression of Craniofacial Dysmorphology in Unilateral Coronal Synostosis: A Mechanistic Hypothesis

AIM

This study chronicles skull base and face development in nonsyndromic unilateral coronal synostosis (UCS) during infancy, to characterize the mechanistic progression of facial dysmorphology.

METHODS

Computed tomography scans from 51 subjects were reviewed (26 UCS, 25 controls) and data were reconstructed. Patients were stratified into 5 age groups. A series of measurements were taken from the reconstructions.

RESULTS

All patients had a unilaterally fused coronal suture at the time of analysis. Asymmetry of the sphenoid wings was present across all age groups. The sphenoid wing ipsilateral to the fused suture consistently had a more acute angle from the midline. At 19 days of age, ipsilateral nasal root and cribriform plate deviation are noted, as well as increased contralateral zygoma antero-posterior length. Patients younger than 2 months also had elongated posterior cranial bases. At 2 to 3 months of age, the cranial base widens in the anterior portion of the middle cranial fossa with an increased ipsilateral pterion to sella distance. The most delayed change observed was the increase in contralateral orbital rim angle at 7 to 12 months of age compared to normal.

CONCLUSION

After suture fusion, sphenoid wing changes are among the earliest restructural malformations to take place. This suggests that the cascade of dysmorphology in UCS originates in the cranial vault, then progresses to the skull base, and lastly to the facial structures. Ipsilateral orbital changes are early facial changes in UCS that begin before 2 months of age. This is then followed by changes in the contralateral face later in development.

Nasal Root Deviation in Unicoronal Craniosynostosis: A Craniometric Analysis of Early and Late Postoperative Outcomes

PURPOSE

Current operative techniques for correcting unicoronal craniosynostosis (UCS) leave the nasal bones untouched, resulting in an unclear long-term impact on nasal root deviation. The purpose of this study is to quantify nasal root deviation in the preoperative and late postoperative setting in patients who have undergone conventional single-staged UCS correction.

METHODS

The authors performed a retrospective, craniometric analysis of nasal root deviation comparing preoperative computed tomography scans, with those of the early, and late postoperative period. Three vectors were analyzed to measure nasal root deviation, one extending from the nasion to the rhinion (nasal bone vector), the second from the rhinion to the anterior nasal spine (nasal aperture vector), and the third from the nasion to the anterior nasal spine (nasal longitudinal vector).

RESULTS

Twenty-five subjects were included in the study. Average ages at the time of preoperative, early, and late postoperative imaging were 0.6 ± 0.3, 0.9 ± 0.6, and 9.3 ± 2.7 years, respectively. Improvement of angular deviation of both the nasal aperture vector and nasal longitudinal vector was observed. Mean angular deviation of the nasal aperture vector was 6.0 ± 1.9 degrees preoperatively, 6.0 ± 2.1 degrees early postoperatively (P = 0.952), and 2.4 ± 2.1 in the late postoperative period (P = 0.013). Mean angular deviation of the nasal longitudinal vector was 5.7+2.0 degrees preoperatively, 5.8 ± 2.3 degrees early postoperatively (P = 0.948), and 3.7 ± 1.6 degrees in the late postoperative period (P = 0.019).

CONCLUSION

Nasal root deviation decreased significantly only in the late postoperative period, lending credence to the notion that though UCS correction does not directly address nasal root deviation, this pathology improves significantly over time.

Quantitative analysis of craniofacial dysmorphology in infants with anterior synostotic plagiocephaly

PURPOSE

The study aimed to identify premature synostosis of "major" and "minor" sutures of the coronal sutural arch and splanchnocranium sutures to evaluate the relationship between craniofacial dysmorphology and the sutural pattern in children with anterior plagiocephaly.

METHODS

A quantitative analysis of the skull base and facial changes was performed on preoperative high-resolution CT images in 18 children with anterior synostotic plagiocephaly and compared with imaging findings in 18 age-matched healthy subjects.

RESULTS

All patients had patent splanchnocranium sutures. Fifteen out of 18 children showed early and isolated synostosis of the unicoronal suture (the major suture of the coronal ring) and were classified in groups II and III according to the classification scheme of anterior synostotic plagiocephaly based on the severity of craniofacial dysmorphology. Premature fusion of the unilateral coronal suture in groups II and III caused a marked asymmetry and reduced growth of the anterior and middle fossae on the synostotic side and a secondary varying severity in terms of asymmetric growth of the facial complex. Although both groups showed anterior displacement of the mandibular articulation on the synostotic side, group II showed only maxillary asymmetry, while group III showed maxillary and mandibular asymmetry.

CONCLUSIONS

In anterior synostotic plagiocephaly, the severity of skull base changes and asymmetric growth of the facial complex is not caused by skull base sutural synostotic involvement but is probably related to the different timing of unilateral coronal suture closure.

The prevalence of strabismus in unilateral coronal synostosis

BACKGROUND

While there is a clear correlation between unilateral coronal synostosis (UCS) and ocular motility abnormalities, the literature provides little information as to the true epidemiology of strabismus, or the underlying etiology of these paralleled pathologies. The purpose of this study is to investigate the rate of oculomotor abnormalities associated with UCS and its management.

METHODS

A retrospective review of all patients identified to have single-suture, nonsyndromic UCS treated by fronto-orbital advancement at a tertiary craniofacial referral center from 1977 to 2013 was performed. Inclusion criteria mandated complete medical, surgical, and ophthalmological records. Patients were evaluated for strabismus both preoperatively and postoperatively, and as to whether eye muscle surgery was performed.

RESULTS

A total of 181 patients underwent treatment for UCS at our institution during the study period, of which 79 met the inclusion criteria. Twenty-nine patients had strabismus prior to any craniofacial surgical intervention. Following fronto-orbital advancement, 23 patients (46 %) developed a new onset strabismus. Fifty-five patients had no change in their preoperative ocular examination, and one patient had resolution of preoperative strabismus. Of the 51 patients who had postoperative strabismus, 30 went on to have eye muscle surgery. There were no statistically significant differences in gender (p=0.477), race (p=0.395), sidedness of suture involvement (p=0.552), or age at intervention (p=0.66) in comparing the group with new postoperative strabismus and those without.

CONCLUSIONS

This study sheds new light on the prevalence of strabismus in UCS, and more importantly, the risk of developing strabismus in the setting of conventional fronto-orbital advancement. This data will allow more accurate preoperative counseling and reinforces the important role of ophthalmologists as members of the multidisciplinary craniofacial team.

Nasal soft-tissue and vault deviation in unicoronal synostosis

BACKGROUND

Unicoronal synostosis (UCS) results in nasal root deviation toward the fused side of the face, resulting in an apparent nasal dorsal deviation to the non-fused side. The impact of the altered radix position on the osteocartilaginous vault and nasal soft tissue has not been analyzed. The purpose of this study is to morphometrically assess the nasal structure and deviation in UCS. We hypothesize the proximal etiology exerts an impact on the distal nasal form, compared to controls.

METHODS

Demographic data were tabulated and computed tomographic information recorded. Three-dimensional reconstruction was created and analyzed digitally (using Surgi Case). Morphometric landmarks were determined and used to perform measurements on the nasal soft tissue and osseous skull surface to evaluate nasal deviation within a midsaggital plane (MSP).

RESULTS

Forty three-dimensional CT scans of 20 UCS patients and 20 control subjects were analyzed. The deviation angle of the nose to the non-fused side was 6.6 ± 2.9° in the bony layer. In the soft-tissue layer, the deviation angle of the nasal dorsum line to the non-fused side was 5.4 ± 3.4°. The tip of the nose showed a significant deviation to the non-fused side (2.2 ± 1.2 mm). Paired landmarks (alares, inferior lateral nostril bases) related to the MSP showed a greater distance on the non-fused side. Paired landmarks related to an intrinsic nasal midline (Nsup-ANS; tip-columella line (TCL)) did not show any significant differences.

CONCLUSION

UCS confers osteocartilaginous and soft-tissue nasal deviation, with the distal nose toward the non-fused side. The nasal root inclination underpins this asymmetry across the midsaggital reference plane. However, the nose in isolation exhibits balanced side-side proportions.