Calvarial Vault Remodeling Technique for Lambdoid Craniosynostosis

SUMMARY

Premature fusion of the lambdoid suture is the most uncommon single-suture synostosis. It presents with a classic "windswept" appearance, a trapezoid-shaped head, and significant skull asymmetry notable for an ipsilateral mastoid bulge and contralateral frontal bossing. Because of the rarity of lambdoid synostosis, little is known about optimal techniques for its treatment. In particular, the proximity of the lambdoid suture to critical intracranial structures such as the superior sagittal and transverse sinuses represents a potential for significant intraoperative bleeding. Prior work has shown that parietal asymmetry persists after repair in these cases. In this article, the authors present a technique for the treatment of unilateral lambdoid craniosynostosis along with two representative cases. This calvarial vault remodeling technique requires the removal of both ipsilateral and contralateral parietal bones. These are moved across hemispheres and reinset on opposite sides to help correct the parietal asymmetry. Obliquely orientated barrel stave osteotomies are performed to provide a safe mechanism for correction of occipital flattening. The authors' early results show improvement in correction of volume asymmetry 1 year postoperatively relative to patients treated with prior calvarial vault remodeling techniques. The authors believe the technique presented here corrects the windswept appearance in patients with lambdoid craniosynostosis and also reduces the potential for complications. Further work will be necessary to confirm this technique's long-term efficacy in a larger cohort.

What can a morphometric study of unoperated children teach us about the natural history of metopic synostosis?

OBJECTIVE

Outcomes of surgical repair of trigonocephaly are well reported in the literature, but there is a paucity of information on the natural history of unoperated children. The authors evaluated a group of unoperated children with metopic synostosis to describe the natural change in head shape over time.

METHODS

A database was screened for scans of children with unoperated trigonocephaly (2010-2021). Multisuture cases and those with a metopic ridge were excluded. Three-dimensional surface scans (3D stereophotogrammetry/CT) were used for morphological analysis. Nine previously published parameters were used: frontal angle (FA30°), anteroposterior (AP) volume ratio (APVR), AP area ratio (APAR), AP width ratios 1 and 2 (APWR1 and APWR2), and 4 AP diagonal ratios (30° right APDR [rAPDR30], 30° left APDR [lAPDR30], 60° right APDR [rAPDR60], and 60° left APDR [lAPDR60]).

RESULTS

Ninety-seven scans were identified from a cohort of 316 patients with a single metopic suture, in which the male-to-female ratio was 2.7:1. Ages at the time of the scan ranged from 9 days to 11 years and were stratified into 4 groups: group 1, < 6 months; group 2, 6-12 months; group 3, 1-3 years; and group 4, > 3 years. Significant improvements were detected in 5 parameters (APVR, APAR, APWR1, rAPDR30, and lAPDR30) over time, whereas no significant differences were found in FA30, APWR2, rAPDR60, and lAPDR60 between age groups.

CONCLUSIONS

Forehead shape (surface area and volume), as well as narrowing and anterolateral contour at the frontal points, differed significantly over time without surgery. However, forehead angulation, narrowing, and anterolateral contour at temporal points did not show significant differences. This knowledge will aid in surgical and parental decision-making.

Multiscale mechanical characterisation of the craniofacial system under external forces

Premature fusion of craniofacial joints, i.e. sutures, is a major clinical condition. This condition affects children and often requires numerous invasive surgeries to correct. Minimally invasive external loading of the skull has shown some success in achieving therapeutic effects in a mouse model of this condition, promising a new non-invasive treatment approach. However, our fundamental understanding of the level of deformation that such loading has induced across the sutures, leading to the effects observed is severely limited, yet crucial for its scalability. We carried out a series of multiscale characterisations of the loading effects on normal and craniosynostotic mice, in a series of in vivo and ex vivo studies. This involved developing a custom loading setup as well as software for its control and a novel in situ CT strain estimation approach following the principles of digital volume correlation. Our findings highlight that this treatment may disrupt bone formation across the sutures through plastic deformation of the treated suture. The level of permanent deformations observed across the coronal suture after loading corresponded well with the apparent strain that was estimated. This work provides invaluable insight into the level of mechanical forces that may prevent early fusion of cranial joints during the minimally invasive treatment cycle and will help the clinical translation of the treatment approach to humans.

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.

Atypical sagittal suture craniosynostosis: pathological considerations for early closure of the anterior part of the sagittal suture

Sagittal suture synostosis is one of the most common craniosynostoses and is often diagnosed by characteristic narrow and long skull shape, scaphocephaly. However, some patients with sagittal suture synostosis do not present with typical scaphocephaly, making early diagnosis difficult. In this study, five cases of characteristic skull deformity showing a narrowing of the cranium posterior to the coronal suture on computed tomography (CT) are presented. The three older children presented with papilledema and intellectual disability and a closed sagittal suture on CT. The two infant cases were diagnosed with the characteristic cranial deformities with aggravation of the deformity over time, but sagittal suture closure was not evident on CT. All patients underwent cranial remodeling surgery. In the two infant cases, the histopathological findings showed that the anterior part of the sagittal suture was firmly fused with fibrous tissue without bony fusion. These findings suggested that narrowing of the cranium posterior to the coronal suture might be due to functional fusion of the anterior portion of the sagittal suture prior to bony fusion. In an infant presenting with such a deformity that shows aggravation of the deformity over time, surgical treatment should be considered.

Improved Facial and Skull-Base Symmetry following Osteotomy and Distraction of Unilateral Coronal Synostosis

BACKGROUND

Unilateral coronal synostosis (UCS) results in a surgically demanding deformation, as the deformity is asymmetric in the calvaria but also presents with facial scoliosis and orbital dystopia. Traditional cranioplasties correct the forehead but have little effect on the face and orbits. In this article, the authors describe a consecutive series of patients operated on for UCS with osteotomy of the fused suture combined with distraction osteogenesis.

METHODS

Fourteen patients (mean age, 8.0 months; range, 4.3 to 16.6 months) were included in this study. The authors measured and compared the orbital dystopia angle, anterior cranial fossa deviation, and anterior cranial fossa cant between preoperative computed tomography results and those at distractor removal.

RESULTS

Blood loss was 6.1 mL/kg (range, 2.0 to 15.2 mL/kg), and length of stay was 4.4 days (range, 3.0 to 6.0 days). The authors observed significant improvements in the median orbital dystopia angle from 9.8 degrees (95% CI, 7.0 to 12.6 degrees) to 1.1 degrees (95% CI, -1.5 to 3.7 degrees) ( P < 0.001), anterior cranial fossa deviation from 12.9 degrees (95% CI, 9.2 to 16.6 degrees) to 4.7 degrees (95% CI, 1.5 to 7.9 degrees) ( P < 0.001), and anterior cranial fossa cant from 2.5 degrees (95% CI, 1.5 to 3.5 degrees) to 1.7 degrees (95% CI, 0.0 to 3.4 degrees) ( P = 0.003).

CONCLUSIONS

Osteotomy combined with a distractor for UCS straightened the face and relieved orbital dystopia by affecting the nose angle relative to the orbits, correcting the deviation of the cranial base in the anterior fossa, and lowering the orbit on the affected side. Furthermore, this technique demonstrated a favorable morbidity profile with low perioperative bleeding and a short inpatient period, suggesting its potential to improve the surgical treatment of UCS.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Surgical Treatment of Trigonocephaly, Simplified Technique for Moderate Cases

BACKGROUND

The prevalence of trigonocephaly has increased worldwide over the past 2 decades. Early identification and appropriate treatment are critical. The aim of this study is to evaluate the outcomes and the effect of metopic suture excision, perisutural frontal bone shave, and bilateral pericranial flap method on the shape of the forehead after surgical correction in infants with moderate trigonocephaly.

METHODS

The present study was performed as a cross-sectional study on 40 infants of 3 to 12 months old with trigonocephalus who underwent metopic suture excision and pericardial flap surgery in Mofid Pediatric Hospital from 2016 to 2022. The definitive diagnosis of patients' trigonocephaly was made based on clinical signs and computed tomography scan findings by a plastic surgeon.

RESULTS

Overall in 40 patients operated by this technique, 23 (57.5%) of cases were males, and 17 (42.5%) were females. The mean age of patients was 7.86 ± 2.22 months. Hospital stay was 2 to 4 days (mean: 3 d), intensive care unit admission was in 33 cases for 24 hours, and no intensive care unit admission for 7 cases. Blood was transfused during surgery for 25 patients, and 15 patients did not require blood transfusion use. Results were evaluated in 6 to 12 months after surgery by 3 independent plastic surgeons, with pre and postoperative photos. Satisfaction with the results of forehead shape was excellent for 60% of patients, good for 37.5%, and moderate for 2.5%. Only one female patient had a recurrence after the surgery.

CONCLUSION

This study showed that the pericranial flap method after full metopic suture excision and frontal shave was very effective in the treatment of infants with moderate trigonocephaly.

The Accuracy of Classification Systems in Nonsyndromic Sagittal Craniosynostosis

Numerous classification systems of nonsyndromic sagittal craniosynostosis (NSC) are applied but none has gained a wide acceptance, since each classification is focused on distinct aspects. The aim of the study was to assess the accuracy of 4 classifications of NSC discussed in the literature by defining the associations among the classifications, individual features (sex, age, cranial index), and objective morphologic criteria (frontal bossing, retrocoronal constriction, sagittal ridge, and occipital bulleting). The study was conducted on anonymized thin-cut CT scans of 133 children with NSC 1 to 12 months old (mean age 5.42 mo). The type of cranial dysmorphology was assessed using 4 classification systems, focusing on skull shape, pattern of sagittal suture closure (Heuzé classification), deformation of skull vault (Sakamoto classification), and a single-dominant feature (David classification). Each patient was also independently investigated for the presence of morphologic criteria. A multivariate analysis was performed to explore the relations among the classifications and assess their accuracy. In the analyzed cohort sphenocephaly (38.3%), CFF type by Heuzé (30.8%), type I by Sakamoto (72.9%), and a central type by David (42.9%) were dominant findings. Regarding the morphologic criteria, frontal bossing was observed the most frequently (91.7%). The age of patients and cranial index differed significantly among the shapes of skull and David classifications ( P <0.001). The shape-based system showed the strongest correlation with other classifications and with measurable variables. Other classifications have much in common and some overlap, but none of them constitutes a standalone system to define all aspects of cranial dysmorphology in NSC.

Spring-assisted posterior vault expansion: a parametric study to improve the intracranial volume increase prediction

Spring-assisted posterior vault expansion has been adopted at the London Great Ormond Street Hospital for Children to treat raised intracranial pressure in patients affected by syndromic craniosynostosis, a congenital calvarial anomaly causing the premature fusion of skull sutures. This procedure involves elastic distractors used to dynamically reshape the skull and increase the intracranial volume (ICV). In this study, we developed and validated a patient-specific model able to predict the ICV increase and carried out a parametric study to investigate the effect of surgical parameters on that final volume. Pre- and post-operative computed tomography data relative to 18 patients were processed to extract simplified patient-specific skull shape, replicate surgical cuts, and simulate spring expansion. A parametric study was performed to quantify each parameter's impact on the surgical outcome: for each patient, the osteotomy location was varied in a pre-defined range; local sensitivity of the predicted ICV to each parameter was analysed and compared. Results showed that the finite element model performed well in terms of post-operative ICV prediction and allowed for parametric optimization of surgical cuts. The study indicates how to optimize the ICV increase according to the type of procedure and provides indication on the most robust surgical strategy.

Outcomes of the early endoscopic-assisted suturectomy for treatment of multisuture craniosynostosis

To present the outcomes and adverse events associated with the endoscopic-assisted, minimally invasive suturectomy in patients with multisuture synostosis. This retrospective cohort study included children < 65 days of age who underwent endoscopic-assisted suturectomy (EAS) for multisuture craniosynostosis at a single tertiary referral center from 2013 to 2021. The primary outcome was calvarial expansion, and the secondary outcome was adverse events. The pre- and post-operative 3-dimensional brain computed tomography (CT) scan was used to calculate the intracranial volume and cephalic index. During a period of 2 years, 10 infants (10-64 days) diagnosed with multisuture synostosis underwent single-stage EAS of every affected suture in our center. The coronal suture was the most prevalent involved suture among our cases. The mean age and weight of the patients were 39 ± 17.5 days and 4.39 ± 0.8 kg, respectively. The surgical procedure took 42 ± 17.4 min of time and caused 46 ± 25.4 mL of bleeding on average. Ninety percent of the operations were considered successful (n = 9) regarding calvarial expansion. There were two complications, one requiring an open vault surgery and one repairing a leptomeningeal cyst. In the eight patients who did not necessitate further interventions, the mean pre-operative intracranial volume was 643.3 ± 189.4 cm3. The follow-up results within the average of 38.9 months after surgery showed that as age increases, the intracranial volume also increased significantly (R: 0.6, P < 0.0001), which suggests continued skull growth in patients who underwent EAS. With the low rate of intra- or post-operative complications and promising results on revising the restricted skull sutures, EAS seems both a safe and effective therapeutic modality in patients with multisuture synostosis, especially if completed in the first months after birth.

Facial skeleton dysmorphology in syndromic craniosynostosis: differences between FGFR2 and no-FGFR2-related syndromes and relationship with skull base and facial sutural patterns

PURPOSE

To assess the role of FGFR2 mutations and sutural synostotic patterns on facial skeleton dysmorphology in children with syndromic craniosynostosis.

METHODS

Preoperative high-resolution CT images in 39 infants with syndromic craniosynostosis were evaluated. Patients were divided into infants with and without FGFR2 mutations; each group was split according to synostotic involvement of minor sutures/synchondroses: isolated or combined involvement of middle (MCF) and posterior cranial fossae (PCF). Quantitative analysis of the midface and mandible measures was performed. Each subgroup was compared with a group of age-matched healthy subjects.

RESULTS

Twenty-four patients with FGFR2 related syndromes were clustered in 3 subgroups: MCF + PCF (8 patients, 5.4 ± 1.75 months), MCF (8 patients, 3.62 ± 1.68 months), and PCF (8 patients, 2.75 ± 0.46 months). Fifteen no-FGFR2 patients were clustered in 2 subgroups: MCF + PCF (7 patients, 9.42 ± 0.78 months) and PCF (8 patients, 7.37 ± 2.92 months). Both FGFR2 and no-FGFR2 groups with involvement of minor sutures coursing in MCF showed more facial sutural synostoses. Children with minor suture/synchondrosis synostosis of MCF (MCF-PCF and MCF subgroups) showed altered position of glenoid fossa and mandibular inclination ([Formula: see text]), but children in the FGFR2 group had also reduced midfacial depth and maxillary length ([Formula: see text]). Children with minor suture/synchondrosis synostosis of PCF (PCF subgroups) had reduced posterior mandibular height, but those children in the FGFR2 group also showed reduced intergonion distance ([Formula: see text]).

CONCLUSIONS

In children with syndromic craniosynostosis, both skull base and facial suture synostosis affect facial dysmorphology/hypoplasia. FGFR2 mutations may worsen facial hypoplasia both acting on bone development and causing an earlier premature closure of facial sutures.

Primary Delayed Onset Craniosynostosis in a Child With ERF-Related Craniosynostosis Syndrome and Familial Cerebral Cavernous Malformation Syndrome

Primary delayed onset craniosynostosis is defined as premature suture fusion that developed despite clear radiographic evidence of normal postnatal calvarial configuration and patent sutures earlier in life. It is rare in the literature and typically presents as secondary synostosis. In this brief clinical study, primary delayed onset craniosynostosis is described in its unique presentation at 4 years of age with a complex genetic history including ERF-related craniosynostosis syndrome and familial cerebral cavernous malformation syndrome. Although the delayed onset clinical course of ERF-related craniosynostosis syndrome has not been well described in the literature, our review suggests that it is distinctive to ERF-related craniosynostosis and should be considered when cases present without a history of trauma, when there is a positive family history, and particularly when cases present late onset; after 1 year of age.

Surgical Management in Isolated Squamosal Craniosynostosis: A Systematic Review

BACKGROUND

Although craniosynostoses involving the major sutures have been well described, the frequency of isolated minor suture craniosynostoses is much lower. Squamosal craniosynostosis (SQS) is a rare form of cranial synostosis, and the paucity of literature has made the creation of a standardized treatment plan difficult. We present a systematic review of the literature on isolated SQS to identify disease characteristics that lead to a need for operative intervention and to delineate patterns in surgical management.

METHODS

A systematic literature review was performed using the electronic databases of PubMed, Scopus, and MEDLINE and the key words "squamosal AND craniosynostosis," "squamous AND craniosynostosis," "squamosal craniosynostosis, "squamosal suture craniosynostosis," and "isolated squamosal craniosynostosis." Only human studies that described presentation and management of SQS were included. A blinded, 2-reviewer analysis of the articles was performed. Data collected included patient and disease characteristics, imaging workup, and treatment specifics, which were analyzed by descriptive statistics.

RESULTS

A total of 19 studies examining 119 patients with SQS were reviewed, with 97 (82%) multisutural cases and 22 isolated cases (18%). Of the isolated cases, 6 (27%) required surgical craniosynostosis repair, of which 1 (17%) had unilateral sutural involvement and 5 (83%) had bilateral involvement. Of the patients with isolated SQS, 7 (32%) had a congenital syndrome and comprised 33% of patients who required surgical intervention. The nonsyndromic patients with isolated SQS who required surgery presented with a wide array of phenotypic findings; 3 patients underwent some form of cranial vault remodeling, whereas 1 patient underwent ventriculoperitoneal shunt only. Of the 4 nonsyndromic patients with isolated SQS who underwent surgical repair, half required operative intervention because of elevated intracranial pressure and the other half because of dysmorphic head shape.

CONCLUSION

The findings of this updated systematic review suggest a trend toward surgical management in bilateral SQS versus unilateral SQS, and that patients with isolated SQS, previously considered to be a nonsurgical finding, should be carefully monitored, as there remains risk of increased intracranial pressure. Pooled systematic review data suggest isolated SQS has a 27% operative intervention rate, with the presence of coexisting syndromic diagnoses increasing that risk.

Natural history of mild trigonocephalic deformities

OBJECTIVE

Ridging along the metopic suture line can be a common cause of concern for parents and has been theorized to represent a mild form of trigonocephaly, a cranial deformity associated with risks of negative cosmetic outcomes, if not surgically corrected. Yet the literature contains sparse reports of long-term cosmetic results or expectations for infants with isolated metopic ridging compared with those with severe trigonocephaly, or even what objective metrics discriminate isolated metopic ridging from severe trigonocephaly. Therefore, the authors' goals for this study were to 1) quantify the degree of frontal deformity among patients with metopic ridge, metopic craniosynostosis, and normocephalic head shapes; and 2) document the natural history of frontal deformities in isolated metopic ridge patients in the 1st year of life.

METHODS

This was a retrospective cohort study of patients with normocephalic head shapes, metopic ridges, and metopic craniosynostoses who presented at < 1 year of age to the Connecticut Children's neurosurgery clinic from January 2019 to December 2021. Data were collected regarding demographics and photograph-based craniometrics.

RESULTS

A total of 212 normocephalic, 34 metopic ridge, and 29 metopic craniosynostosis patients were included. Both the normocephalic and metopic ridge groups had a significantly higher anterior arc angle (AAA) value compared with the metopic craniosynostosis group (p < 0.0001). The AAA did not differ significantly among normocephalic patients and those with ridging. Over the course of 1 year of follow-up, patients with metopic ridging demonstrated a slight decrease in AAA values, but overall remained within the same range as normocephalic patients.

CONCLUSIONS

Photograph-based craniometrics suggest that metopic ridge patients with frontal bone angulations > 2.2 radians have a mild degree of frontal constriction that does not significantly worsen over the 1st year of life.

Can Craniosynostosis be Diagnosed on Physical Examination? A Retrospective Review

Craniosynostosis is a developmental craniofacial defect in which one or more sutures of the skull fuse together prematurely. Uncorrected craniosynostosis may have serious complications including elevated intracranial pressure, developmental delay, and blindness. Proper diagnosis of craniosynostosis requires a physical examination of the head with assessment for symmetry and palpation of sutures for prominence. Often, if craniosynostosis is suspected, computed tomography (CT) imaging will be obtained. Recent literature has posited that this is unnecessary. This study aims to address whether physical examination alone is sufficient for the diagnosis and treatment planning of single suture craniosynostosis. Between 2015 and 2022, the Divisions of Pediatric Neurosurgery and Pediatric Plastic Surgery at UTHealth Houston evaluated 140 children under 36 months of age with suspected craniosynostosis by physical examination and subsequently ordered CT imaging for preoperative planning. Twenty-three patients received a clinical diagnosis of multi-sutural or syndromic craniosynostosis that was confirmed by CT. One hundred seventeen patients were diagnosed with single suture craniosynostosis on clinical examination and follow-up CT confirmed suture fusion in 109 (93.2%) patients and identified intracranial anomalies in 7 (6.0%) patients. These patients underwent surgical correction. Eight (6.8%) patients showed no evidence of craniosynostosis on CT imaging. Treatment for patients without fused sutures included molding helmets and observation alone. This evidence suggests that physical examination alone may be inadequate to accurately diagnose single suture synostosis, and surgery without preoperative CT evaluation could lead to unindicated procedures.

Presentation and Treatment of a Patient With Jacobs Syndrome and Metopic Craniosynostosis

Jacobs syndrome is a rare trisomy (47, XYY) found in ~1 in 1000 male children associated with infertility, autism spectrum disorders, macrocephaly, hypertelorism, tall stature, and macroorchidism. Diagnosis is often delayed due to relatively subtle phenotypic changes. Craniosynostosis, a fusion of the cranial sutures, has been described in ~1 in 2000 live births, of which 25% are related to a diagnosed syndrome with the most common being Apert and Crouzon. Craniosynostosis does not have a known association with Jacobs syndrome and no prior cases have been reported. This case report seeks to describe the presentation and treatment of a patient with Jacobs syndrome and metopic craniosynostosis.

Technical evolution of pediatric neurosurgery: craniosynostosis from 1972 to 2023 and beyond

Very few clinical entities have undergone so many different treatment approaches over such a short period of time as craniosynostosis. Surgical treatments for this condition have ranged from simple linear craniectomies, accounting for the specific role of cranial sutures in assuring the normal growth of the skull, to more complex cranial vault reconstructions, based on the perceived role of the skull base in affecting the growth of the skull. While a great deal of evolution has occurred, there remains controversy regarding the ideal treatment including the best surgical technique, the optimal age for surgery, and the long-term morphological and neurodevelopmental outcomes. The evolution of the surgical management of craniosynostosis in the last 50 years has been affected by several factors. This includes the awareness of needing to operate on affected children during infancy to achieve the best results, the use of multistage operations, the availability of more sophisticated surgical tools, and improved perioperative care. In some forms of craniosynostosis, the operations can be carried out at a very young age with low morbidity, and with the postoperative use of a molding helmet, springs, or distractors, these operations prove to be as effective as traditional larger cranial reconstructions performed in older children. As a consequence, complex surgical operations have become progressively less utilized. A second relevant advance was the more recent advent of a molecular diagnosis, which allowed us to understand the pathogenesis of some associated malformations and neurodevelopmental issues that were observed in some children despite appropriate surgical treatment. Future research should focus on improving the analysis of longer-term outcomes and understanding the natural history of craniofacial conditions, including what issues persist despite optimal surgical correction. Progress in molecular investigations concerning the normal and pathological development of cranial sutures could be a further significant step in the management of craniosynostosis, possibly favoring a "medical" treatment in the near future. Artificial intelligence will likely have a role in establishing the diagnosis with less reliance on radiographic studies and in assisting with surgical planning. Overall, much progress has been made, but there remains much to do.

Squamosal Suture Synostosis: An Under-Recognized Phenomenon

INTRODUCTION

The squamosal suture (SQS) joins the temporal to the parietal bones bilaterally and is a poorly described site of craniosynostosis. SQS fusion is thought to occur as late as the fourth decade of life and beyond; however, we have incidentally noted its presence among our pediatric patients and hypothesize that it may occur earlier in life and more frequently than previously believed.

METHODS

A retrospective review of imaging performed on pediatric patients was completed to identify patients with SQS synostosis. This included a review of clinical notes as well as computed tomography (CT) images obtained by our craniofacial clinic. Relevant patient data and imaging were reviewed.

RESULTS

Forty-seven patients were identified with SQS synostosis, 21 were female (45%). Age at the time of radiographic diagnosis was 10.1 ± 8.4 years (range 17 days to 27 years). A majority of patients had bilateral SQS synostosis (57%), with a relatively even distribution of unilateral right (23%) versus left (19%). SQS was an isolated finding (no other suture involvement) in 15 patients (32%), all of whom were normocephalic and did not require surgical intervention. Thirty-two patients (68%) had concomitant craniosynostosis of other sutures, most commonly sagittal and coronal. Nine patients (19%) underwent surgery to correct cranial malformations-all these patients had multi-suture synostosis (P = 0.012). Twenty-seven patients (57%) had SQS synostosis diagnosed incidentally compared to 20 (43%) who were imaged with suspicion for synostosis. In those who were symptomatic, common findings included developmental delay, elevated intracranial pressure, hydrocephalus, seizures, and visual/hearing impairments. Ten patients (21%) were syndromic, the most frequent of which was Crouzon syndrome. No single pattern of calvarial malformation could be definitively described for SQS synostosis.

CONCLUSION

Given that most isolated SQS synostosis cases were normocephalic, asymptomatic, and discovered incidentally, it is likely that there are many cases of unidentified SQS synostosis. The significance of SQS synostosis is currently unclear, and warrants further investigation into this phenomenon, its natural course, and its potential presence in the spectrum of normal development.

A Novel Phenotype of Calvarial Thickening and Increased Rates of Premature Calvarial Suture Closure in Children With Chronic Lung Disease

PURPOSE

The purpose of this study was to characterize a novel type of calvarial thickening and provide objective measurements of skull thickness and calvarial suture morphology in patients with bronchopulmonary dysplasia.

METHODS

Infants with severe bronchopulmonary dysplasia who also had undergone computed tomography (CT) scans were identified from the neonatal chronic lung disease program database. Thickness analysis was performed using Materialise Mimics.

RESULTS

The chronic lung disease team treated 319 patients during the study interval of which, 58 patients (18.2%) had head CT available. Twenty-eight (48.3%) were found to have calvarial thickening. The rate of premature suture closure in the study population was 36.2% (21 of 58 patients), with 50.0% of affected cohort having evidence of premature suture closure on the first CT scan. Multivariate logistic regression identified 2 risk factors, requiring invasive ventilation at 6 months of age and fraction of inspired oxygen requirement at 6 months of age. Increased head circumference at birth protected against the development of calvarial thickening.

CONCLUSIONS

We have described a novel subset of patients with chronic lung disease of prematurity who have calvarial thickening with remarkably high rates of premature closure of cranial sutures. The exact etiology of the association is unknown. In this patient population with radiographic evidence of premature suture closure, operative decision should be made after considering unequivocal evidence of elevated intracranial pressure or dysmorphology and balanced against the risk of the procedure.

A Systematic Review of Idiopathic Secondary Stenosis Following Index Surgery for Craniosynostosis

BACKGROUND

Primary craniosynostosis is a congenital craniofacial disorder in which cranial sutures prematurely close. Iatrogenic secondary stenosis is abnormal cranial suture closure caused by surgical manipulation of the suture. In contrast, idiopathic secondary stenosis develops in a suture that did not undergo surgical manipulation. The objective of this systematic review was to consolidate and characterize the incidence, classification, and management of idiopathic secondary stenosis in the literature.

METHODS

Literature from PubMed, Web Of Science, and EMBASE from 1970 to March 2022 was reviewed. The following information was extracted for individual patients: incidence of idiopathic secondary stenosis, index primary craniosynostosis, primary surgical correction, presenting signs of secondary stenosis, management, and further complications.

RESULTS

Seventeen articles detailing 1181 patients were included. Ninety-one developed idiopathic secondary stenosis (7.7%). Only 3 of these patients were syndromic. The most common index craniosynostosis was sagittal synostosis (83.5%). The most common suture undergoing idiopathic secondary stenosis was the coronal suture (91.2%). Patients presented at a median age of 24 months. The most common presenting sign was a radiologic finding (85.7%), although some patients presented with headache or head deformity. Only 2 patients, both syndromic, had complications following surgical correction of secondary stenosis.

CONCLUSIONS

Idiopathic secondary stenosis is a rare, long-term complication following index surgical repair of craniosynostosis. It can occur following any surgical technique. It most commonly affects the coronal suture but can affect any of the sutures, including pansynostosis. Surgical correction is curative in nonsyndromic patients.

Long-term neurocognitive outcomes in 204 single-suture craniosynostosis patients

PURPOSE

Craniosynostosis, which describes premature fusion of one or more cranial sutures, has been associated with a variety of neurocognitive deficits. We sought to explore the cognitive profiles of the various types of single-suture, non-syndromic craniosynostosis (NSC).

METHODS

A retrospective review of children 6-18 years old with surgically corrected NSC who underwent neurocognitive testing (Weschler Abbreviated Scale of Intelligence, Beery-Buktenica Developmental Test of Visuomotor Integration) from the years 2014-2022 was conducted.

RESULTS

204 patients completed neurocognitive testing (139 sagittal, 39 metopic, 22 unicoronal, 4 lambdoid suture). 110 (54%) of the cohort was male, and 150 (74%) were White. Mean IQ was 106.10±14.01 and mean age at surgery and testing were 9.0±12.2 months and 10.9±4.0 years, respectively. Sagittal synostosis was associated with higher scores than metopic synostosis, with significant differences in verbal IQ (109.42±15.76 vs 101.37±10.41), full-scale IQ (108.32±14.44 vs 100.05±11.76), visuomotor integration (101.62±13.64 vs 92.44±12.07), visual perception (103.81±12.42 vs 95.87±11.23), and motor coordination (90.45±15.60 vs 84.21±15.44). Sagittal synostosis was associated with significantly higher scores for visuomotor integration (101.62±13.64 vs 94.95±10.24) and visual perception (103.81±12.42 vs 94.82±12.75) than unicoronal synostosis.

CONCLUSIONS

Compared to patients with sagittal synostosis, patients with metopic synostosis exhibited lower scores in verbal IQ, full-scale IQ, visuomotor integration, visual perception, and motor control after surgical correction. Despite surgical correction for premature metopic suture fusion, the effect on the adjacent frontal lobe and white matter connections to other regions of the brain may have a lasting functional impact. Patients with unicoronal synostosis exhibited lower visuomotor integration and visual perception scores.

Flexible endoscope-assisted suture release and barrel stave osteotomy for the correction of sagittal synostosis

OBJECTIVE

Early suturectomy with a rigid endoscope followed by orthotic cranial helmet therapy is an accepted treatment option for single-suture craniosynostosis. To the authors' knowledge, flexible endoscope-assisted suture release (FEASR) has not been previously described. Presented herein is their experience with FEASR for the treatment of isolated sagittal craniosynostosis.

METHODS

A retrospective analysis of the health records of patients who had undergone FEASR between March 2018 and December 2020 was performed. Patients under the age of 6 months who had been diagnosed with isolated sagittal synostosis were considered eligible for FEASR. Exclusion criteria included syndromic synostosis or multiple-suture synostosis. The cephalic index, the primary measure of the cosmetic endpoint, was calculated at prespecified intervals: immediately preoperatively and 6 weeks and 12 months postoperatively. Parental satisfaction with the cosmetic outcome was determined throughout the clinical follow-up and documented according to a structured questionnaire for the first 12 months.

RESULTS

A total of 18 consecutive patients met the criteria for study inclusion. The mean patient age at the time of surgery was 3.4 months (range 2-6 months). All patients underwent a wide craniectomy with no need to convert to an open procedure. The mean craniectomy width was 3.61 cm. Estimated blood loss ranged from 5 to 30 ml. The mean operative time was 75 minutes. No intraoperative complications were observed. The average length of stay was 2.6 days. The mean cephalic index was 67.7 preoperatively, 77.1 at 6 weeks postoperatively, and 76.3 at 1 year postoperatively. The mean percentage change in the cephalic index from preoperatively to the 12-month follow-up was 10.44 (p < 0.001). The mean follow-up was 17 months (range 12-28 months). All parents were satisfied with the cosmetic outcome of the procedure. No patients developed symptoms of raised intracranial pressure (ICP) or needed invasive ICP monitoring during the follow-up period. No patients required reoperation.

CONCLUSIONS

In this modest single-hospital series, the authors demonstrated the feasibility of FEASR in treating sagittal synostosis with favorable cosmetic outcomes. The morbidity profile and resource utilization of the procedure appear similar to those of procedures conducted via traditional rigid endoscopy.

Clinical Analysis of the Effects of Cranial Suture Reconstruction and Frontal Frame Band Transfer in the Operation of Premature Closure of Coronal Suture in Infants

AIM

To compare, and to analyze the effects of fronto-orbital band anterior displacement in the operation of premature closure of coronal suture in infants.

MATERIAL AND METHODS

A total of 31 infants with premature closure of coronal suture were randomly divided into two groups; experimental group (n=16) and control group (n=15). In the experimental group, the skull model was reconstructed by an imaging examination and three-dimensional (3D) printing technique before the operation, and the fronto-orbital band was anteriorly displaced during the operation to guide the surgical treatment of craniosynostosis. In the control group, the skull model was reconstructed by an imaging examination and 3D printing technique before the operation, and the fronto-orbital band was not anteriorly displaced during the operation by the same operator. The surgical effects of the two groups were compared.

RESULTS

During the 12-month follow up after the operation, the cephalic index of short head deformity in the experimental group was 80.7 ± 1.1, while that in the control group was 89.3 ± 4.5. There was a significant difference between the two groups.

CONCLUSION

Fronto-orbital band anterior displacement may guide the operation of craniosynostosis and significantly improve the effectiveness of surgical treatment of children with premature closure of coronal suture, which is worth popularizing in the clinical management of cases.

Scaphocephaly and increased intra-cranial pressure in non-operated adults: A controlled anthropological study on 21 skulls

AIM AND SCOPE

The prevalence of increased intra-cranial pressure (ICP) in patients with scaphocephaly is controversial. Here, based on anthropological material, we aimed to determine whether adults with non-operated sagittal synostosis show indirect signs of increased ICP.

MATERIALS AND METHODS

Thirty-eight dry skulls (21 skulls with sagittal craniosynostosis and 17 controls) were selected from the collections of the National Museum of Natural History (Paris, France). All skulls registered as 'fused sagittal suture' or 'scaphocephaly' in the registry of the Museum were included. All had total fusion of the sagittal suture. Controls were selected within skulls of similar origin (France), without visible craniofacial anomalies. The 38 skulls were CT-scanned using a standard medical CT-scan with a protocol dedicated to dry bone imaging. Eight radiological signs associated with raised ICP were assessed: (1) calvaria and (2) skull base thinning, (3) dorsum sellae erosion, (4) sella turcica lengthening, (5) copper beaten skull, (6) suture diastasis, (7) persistent metopic suture, and (8) small frontal sinus. Scaphocephaly was assessed based on head circumference, cranial index, intra-cranial volume, fronto-nasal angle, and inter-zygomatic distance. Linear and non-linear logistic models were used to compare groups.

RESULTS

19/21 skulls with sagittal synostosis were significantly scaphocephalic. None of the criteria for ICP were significantly different in skulls with scaphocephaly relative to controls. Nevertheless, 5 individual skulls with scaphocephaly had ≥ 3 signs in favor of a history of raised ICP. We do not report the significant prevalence of indirect signs of raised ICP in adults with scaphocephaly. These results do not allow ruling out a history of early raised ICP or of minor prolonged raised ICP. Even though our findings support the fact that scaphocephaly is not significantly associated with prolonged raised ICP, individual cases (5/21) with clear signs in favor of a history of brain compression indicate that scaphocephaly correction should be considered as a functional procedure until the production of clear evidence. Cognitive assessments of non-operated adult patients with scaphocephaly could contribute to tackle this recurring question in craniofacial surgery.

A case of early obliteration of the sagittal suture without effect on cranial deformation

This paper describes a unique case of craniosynostosis in a female skull in which sagittal sutures were completely fused by adolescence. Despite sagittal synostosis, the skull was of normal shape and size. Regarding craniometric features, the synostotic normocephalic skull was markedly different than that of scaphocephalic skulls which typically result from premature obliteration of the sagittal suture.

Endoscopic treatment of sagittal suture synostosis - a critical analysis of current management strategies

While many centers nowadays offer minimally invasive techniques for the treatment of single suture synostosis, surgical techniques and patient management vary significantly. We provide an overview of how scaphocephaly treated with endoscopic techniques is managed in the reported series and analyze the crucial steps that need to be dealt with during the management process. We performed a review of the published literature including all articles that examined sagittal-suture synostosis treated with endoscopic techniques as part of single- or multicenter studies. Fourteen studies reporting results of 885 patients were included. We identified 5 key steps in the management of patients. A total of 188 patients were female and 537 male (sex was only specified in 10 articles, for 725 included patients, respectively). Median age at surgery was between 2.6 and 3.9 months with a total range from 1.5 to 7.0 months. Preoperative diagnostics included clinical and ophthalmologic examinations as well as neuropsychological and genetic consultations if needed. In 5 publications, a CT scan was routinely performed. Several groups used anthropometric measurements, mostly the cephalic index. All groups analyzed equally recommended to perform endoscopically assisted craniosynostosis surgery with postoperative helmet therapy in children < 3 months of age, at least for non-syndromic cases. There exist significant variations in surgical techniques and patient management for children treated endoscopically for single suture sagittal synostosis. This heterogeneity constitutes a major problem in terms of comparability between different strategies.

Suture Cells in a Mechanical Stretching Niche: Critical Contributors to Trans-sutural Distraction Osteogenesis

Trans-sutural distraction osteogenesis has been proposed as an alternative technique of craniofacial remodelling surgery for craniosynostosis correction. Many studies have defined the contribution of a series of biological events to distraction osteogenesis, such as changes in gene expression, changes in suture cell behaviour and changes in suture collagen fibre characteristics. However, few studies have elucidated the systematic molecular and cellular mechanisms of trans-sutural distraction osteogenesis, and no study has highlighted the contribution of cell-cell or cell-matrix interactions with respect to the whole expansion process to date. Therefore, it is difficult to translate largely primary mechanistic insights into clinical applications and optimize the clinical outcome of trans-sutural distraction osteogenesis. In this review, we carefully summarize in detail the literature related to the effects of mechanical stretching on osteoblasts, endothelial cells, fibroblasts, immune cells (macrophages and T cells), mesenchymal stem cells and collagen fibres in sutures during the distraction osteogenesis process. We also briefly review the contribution of cell-cell or cell-matrix interactions to bone regeneration at the osteogenic suture front from a comprehensive viewpoint.

A study of 285 cases of cranial vault suture closure in Chinese adults

PURPOSE

To examine the presence and characteristics of cranial vault suture closure in Chinese adults and to explore whether craniosacral therapy (CST) manipulation is rational from the anatomical perspective.

METHODS

Anthropological non-metric observation and craniometry were used to study 285 dry skull specimens of Chinese adults.

RESULTS

A total of 91 specimens with closed extracranial sutures were observed, with an occurrence rate of 31.93%. Based on the mode of closure, there were 32 cases of single type closure, with sagittal suture closure predominating with 20 cases (21.98%); 59 cases of composite closure, with a partial closure of coronal suture + sagittal suture + lambdoid suture predominating with 26 cases (28.57%). In terms of the degree of closure, there were 13 cases (14.28%) of sagittal suture grade 0 closure and 78 cases (85.72%) of grade 1 - 4 closure; 34 cases (37.36%) of coronal suture grade 0 closure and 57 cases (62.64%) of grade 1 - 4 closure; 47 cases (51.65%) of lambdoid suture grade 0 closure and 44 cases (48.35%) of grade 1 - 4 closure. The segment and degree of coronal suture closure (46, 80.7%) and lambdoid suture (31, 70.45%) were mostly left-right symmetrical. The bone surfaces on either side of the cranial vault sutures are embedded in each other, forming a rough, complex and interlocking bone-suture-bone structure.

CONCLUSION

This study observed the closure of the cranial vault suture, summarized its characteristics, and explored the irrationality of the CST manipulation. The anatomical characteristics of the cranial suture dictate that manipulation cannot push the cranial suture at will.

Facial Suture Pathology in Syndromic Craniosynostosis: Human and Animal Studies

BACKGROUND

Facial deformities in syndromic craniosynostosis are not only functionally, psychosocially, and aesthetically impairing but also notoriously challenging to reconstruct. Whether facial suture synostosis plays a significant role in the pathogenesis of these deformities is inadequately studied in human patients.

METHODS

The MEDLINE database was queried using a methodologically generated search term inventory. Article inclusion was adjudicated by 2 authors after independent review. Articles provided insight into facial suture involvement in either syndromic craniosynostosis patients or animal models of disease.

RESULTS

Comprehensive review yielded 19 relevant articles meeting inclusion criteria. Mid-20th century craniofacial biologists characterized how patent facial sutures are essential for normal postnatal facial development. They also posited that premature ossification disrupts growth vectors, causing significant dysmorphologies. Recently, facial suture synostosis was found to cause midfacial deformities independent of cranial base pathology in mouse models of syndromic craniosynostosis. Few recent studies have begun exploring facial suture involvement in patients, and although they have paved the way for future research, they bear significant limitations.

CONCLUSIONS

The hypothesis that facial suture synostosis acts in conjunction with cranial base pathology to produce the prominent, multifocal facial deformities in syndromic craniosynostosis may fundamentally alter surgical management and warrants further investigation. Methodically evaluating the literature, this review synthesizes all basic science and human clinical research thus far on the role of facial sutures in syndromic craniosynostosis and elucidates important topics for future research. We ultimately identify the need for rigorous imaging studies that longitudinally evaluate facial osteology across patients with various craniosynostosis syndromes.

Using Cranial Sutures in a Single-Step Frame-Guided Resection and Reconstruction for Intraosseous Meningiomas: Technical Note

BACKGROUND

Single-stage surgical treatment of cranial intraosseous meningiomas includes complete tumor resection followed by aesthetic reconstruction. Tailored tumor resection with a computer-aided design/computer-aided manufacturing custom-made implant for the defect has been advocated in recent years to achieve a satisfactory cosmetic result with reduced operative time and fewer complications. However, several technical nuances related to the area of osseous removal may compromise cranioplasty.

METHODS

We present 2 cases of intraosseous meningiomas (sphenoid wing and retromastoid) to illustrate a step-by-step approach, from preoperative planning to single-step surgery.

RESULTS

For each case, a customized frame template delimiting bone removal was designed using cranial sutures as anatomical landmarks for precise placement of the cranioplasty template over the area of interest.

CONCLUSIONS

Custom templates based in cranial sutures may benefit single-step frame-guided resection and reconstruction of intraosseous tumors with compelling results.

Minimally invasive endoscopically assisted remodelation (MEAR) of sagittal craniosynostosis: an alternative technique to open and endoscopic procedures with cranial orthosis time span reduction

INTRODUCTION

Sagittal craniosynostosis represents the most frequent simplex skull suture pathology. There are currently several operative approaches to this defect. Minimally invasive techniques are preferred for young infants. Since July 2017, we have employed endoscopically assisted craniectomies followed by cranial orthosis. Gradually, we have developed our modified technique, the minimally invasive endoscopically assisted remodelation (MEAR).

SURGICAL TECHNIQUE

MEAR is a combination of principles gained from classical cranial vault remodeling techniques and minimal invasive approaches. The long and wider lateral osteoectomies performed in the parietal and occipital bones along with loosening of the periosteum and dura adhesions at the lambdoid sutures lead to early correction of parieto-occipital dimensions.

RESULTS

Thirty-one consecutive patients with scaphocephaly underwent MEAR. The median preoperative cephalic index of 67 units (P25:63.3, P75:70) was improved to a median postoperative cephalic index of 77 units (P25:75, P75: 81). Sufficient correction was achieved in all patients. Cranial orthosis was needed for a median of 1.5 months (P25:1, P75:2). We had no major surgical complications in this pilot series.

CONCLUSIONS

With MEAR, we have achieved good cosmetic results. Duration of cranial orthosis was significantly shortened compared to conventional endoscopic-assisted procedures.

Combined unilateral coronal-lambdoid suture synostosis: surgical outcome of suturectomy and postoperative helmet therapy

INTRODUCTION

Nonsyndromic, multi-suture craniosynostosis is not common, especially those involving unilateral coronal and lambdoid sutures. Based on the experience on 6 cases, we analyzed the skull morphology of combined unilateral coronal-lambdoid suture synostosis and evaluated the surgical outcome of suturectomy.

METHODS

Patients who underwent an operation for craniosynostosis in Seoul National University Children's Hospital from 2010 to 2018 were reviewed. For qualitative analysis of the surgical outcome, five typical morphologic characteristics (ipsilateral superior orbital rim deviation, deviation of the nasal ridge, ipsilateral frontal flattening, contralateral parietal bulging, ipsilateral occipitomastoid bulging) in unilateral coronal-lambdoid suture synostosis were evaluated based on medical photos, plain skull radiographs, and CT scans. For quantitative analysis, three parameters (nasal root deviation, orbital asymmetry, posterior skull base deviation) were measured.

RESULTS

Among 316 patients with craniosynostosis, 41 patients had nonsyndromic, multi-suture synostosis. There were 6 unilateral coronal-lambdoid suture synostosis patients who were all treated with suturectomy. Qualitative evaluation of the postoperative outcome revealed that the nasal root and orbital rim deviations and the contralateral occipitomastoid bulging showed satisfactory improvements. However, ipsilateral frontal flattening and contralateral parietal bulging were improved but still present in most cases. Quantitative, craniometric analysis supported the qualitative outcomes. The nasal ridge deviation angle was corrected from 7.04 to 1.79 degrees. The posterior skull base deviation angle improved from 6.29 to 3.55 degrees.

CONCLUSION

Unilateral coronal-lambdoid suture synostosis suturectomy followed by helmet therapy resulted in favorable outcomes, although the correction of frontal flattening was less satisfactory than the other measures. Considering the minimal invasiveness of the treatment, suturectomy may be a viable option for these patients.

A population-specific material model for sagittal craniosynostosis to predict surgical shape outcomes

Sagittal craniosynostosis consists of premature fusion (ossification) of the sagittal suture during infancy, resulting in head deformity and brain growth restriction. Spring-assisted cranioplasty (SAC) entails skull incisions to free the fused suture and insertion of two springs (metallic distractors) to promote cranial reshaping. Although safe and effective, SAC outcomes remain uncertain. We aimed hereby to obtain and validate a skull material model for SAC outcome prediction. Computed tomography data relative to 18 patients were processed to simulate surgical cuts and spring location. A rescaling model for age matching was created using retrospective data and validated. Design of experiments was used to assess the effect of different material property parameters on the model output. Subsequent material optimization-using retrospective clinical spring measurements-was performed for nine patients. A population-derived material model was obtained and applied to the whole population. Results showed that bone Young's modulus and relaxation modulus had the largest effect on the model predictions: the use of the population-derived material model had a negligible effect on improving the prediction of on-table opening while significantly improved the prediction of spring kinematics at follow-up. The model was validated using on-table 3D scans for nine patients: the predicted head shape approximated within 2 mm the 3D scan model in 80% of the surface points, in 8 out of 9 patients. The accuracy and reliability of the developed computational model of SAC were increased using population data: this tool is now ready for prospective clinical application.

Craniosynostosis: A Reversible Pathology?

The formation of the cranial sutures, in utero, occurs when the ossification of the skull bones reaches predestined positions around gestational week 15 to 20. Craniosynostosis, and the consequent skull shape deformities, is treated with surgery including osteotomies of the fused sutures. The occasional appearance of a new suture in the osteotomy lines has previously been described as sporadic events. In this retrospective study, a 4-year consecutive series of osteotomies combined with springs for craniosynostosis were systematically analysed regarding the appearance of neosutures. In total, 84 patients were included and in 16 patients (19%) a new radiologically normal suture appeared in a part of the suture that was completely closed preoperatively. Additionally, in 7 patients (8%) a new suture appeared in a part of the suture that had a discernible suture prior to surgery.In conclusion, in this consecutive and well-defined patient cohort operated for craniosynostosis, the formation of a neosuture is not a rare, and speculatively not a random, event. The appearance of a new suture long after the normal time period for suture formation in utero indicates that the craniosynostosis may just as well be caused by disturbed formation of the suture as actual premature closure.

Telescoping With Multiple Revolution Cranial Osteotomies in Patients With Simple Craniosynostosis

Simple craniosynostosis is a cranial disease characterized by the premature closure of the cranial sutures, it develops during the first years of life and affects 1 in every 2000 to 2500 births worldwide (1). The cranial growth alteration occurs as parallel flattening to the compromised sutured with compensatory bulging in a perpendicular vector. Currently, The Suturectomy is the gold validated surgical treatment, that besides the dynamic Cranioplasties of multiples revolutions allows the design of bone flaps and therefore the correction of the secondary deformities caused by the synostosis. This multicenter descriptive study assessed a 20 series of cases (6 Plagiocephaly, 13 Scaphocephaly, 1 Brachycephaly) obtained in Cali, Colombia, that underwent surgery between January of 2014 and December of 2017, applying a Suturectomy surgery with additional telescoping of multiple revolution cranial osteotomies. The authors observe no clinical complications in the recruited patients regarding postoperative period of the described surgical technique (1, 90, and 180 days), thereby obtaining excellent outcomes on the maintained suture distraction focused on the assessment of the 3D reconstruction computed tomography scans.

Use of Absorbable Poly (D,L) Lactic Acid Plates in Cranial-Vault Remodeling: Presentation of the First Case and Lessons Learned about Its Use

Objective

To present the first clinical use of a new bioabsorbable material, poly (D,L) lactic acid (PDLLA), in pediatric cranial-vault remodeling procedures. This discussion will highlight the benefits and detriments of PDLLA in comparison with currently used absorbable plating systems.

Design

This was a case study documenting the first North American case in which PDLLA was used to treat craniosynostosis.

Materials and Methods

Evaluation of pure PDLLA, a copolymer product of the mixture of poly L-lactic acid and its D-isomer, was used in an 8-month-old boy with a severe phenotypic expression of sagittal craniosynostosis. No signs of elevated intracranial pressure were present, and the neurological examination did not show impairments. Total cranial-vault remodeling with the “hung-span” technique was performed. The Resorb X system, containing 2.2-mm screws and 0.6- to 1-mm-thick plates, was used to stabilize the reconstructed cranial vault.

Results

No surgical complications occurred. The preoperative cranial index measured 62. The scaphocephalic appearance of the skull was eliminated, and the cranial index was normalized to 77. The screws and plates were less palpable than other plating systems. Twelve months postoperatively, none of the plates and screws were identifiable by external palpation.

Conclusion

Resorb X has been successfully used in the treatment of sagittal craniosynostosis. Its rapid rate of resorption and lower profile make it an advantageous system for pediatric skull reconstruction. This represents the first use of this product in the United States for any pathology.

Effect of Piezoelectric Sutural Ostectomies on Accelerated Bone-Borne Sutural Expansion

PURPOSE

The present study investigated the effect of piezoelectric sutural ostectomies on accelerated bone-borne sutural expansion.

MATERIALS AND METHODS

Sixteen male New Zealand white rabbits (20 to 24 weeks old) were randomly divided into 4 experimental groups (n = 4): group 1, conventional rapid sutural expansion; group 2, accelerated sutural expansion; group 3, accelerated sutural expansion with continuous ostectomy; and group 4, accelerated sutural expansion with discontinuous ostectomy. All sutural ostectomies were performed using a piezoelectric instrument (Woodpecker DTE, DS-II, Guangxi, China) before expander application with the rabbits under anesthesia. Modified hyrax expanders were placed across the midsagittal sutures of the rabbits and secured with miniscrew implants located bilaterally in the frontal bone. The hyrax expanders were activated 0.5 mm/day for 12 days (group 1) or with a 2.5-mm initial expansion, followed by 0.5 mm/day for 7 days (groups 2 to 4). After 6 weeks of retention, the bone volume fraction, sutural separation, and new bone formation were evaluated using micro-computed tomography and histomorphometry. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests and Spearman's rho correlation (P < .05).

RESULTS

Ranking of the median sutural separation was as follows: group 1, 3.05 mm; group 2, 3.97 mm; group 4, 4.78 mm; and group 3, 5.66 mm. The least and most bone formation were observed in groups 1 (63.63%) and 3 (75.93%), respectively. Spearman's correlation showed a strong, positive, and significant correlation (r = 0.932; P < .01) between the new sutural bone formation and amount of sutural separation.

CONCLUSIONS

Piezoelectric sutural ostectomies increased the rate of sutural separation and promoted new sutural bone formation/osteogenesis. Continuous ostectomy gave better results than discontinuous ostectomy.

Primary delayed onset craniosynostosis in a child demonstrated by serial computed tomography imaging

Primary delayed onset craniosynostosis is a rarely reported phenomenon. The unique case of a 2-year-old boy who had computed tomography (CT) scans performed 20 months apart demonstrating the post-gestational development of sagittal suture craniosynostosis is presented. The otherwise healthy male initially presented to the emergency department at age 7 months with soft tissue swelling over his left parietal region secondary to a fall. A CT scan revealed a possible left parietal skull fracture without intracranial pathology and patent cranial sutures with a normocephalic calvarial configuration. Twenty months later, his paediatrician referred the boy to the craniofacial service for evaluation of progressive dolichocephaly. A new CT scan showed complete fusion of the sagittal suture with resultant biparietal narrowing, frontal bossing, and occipital prominence. The patient subsequently underwent uncomplicated frontoparietal craniotomy with calvarial vault reconstruction. Prior reports in the literature of cases of non-syndromic primary delayed onset craniosynostosis all lack 'pre-synostosis' CT imaging that proves post-birth patency of the cranial sutures. This case report documents CT demonstrating true primary delayed onset craniosynostosis.

Objective classification system for sagittal craniosynostosis based on suture segmentation

PURPOSE

Spring-assisted surgery is an effective and minimally invasive treatment for sagittal craniosynostosis (CSO). The principal barrier to the advancement of spring-assisted surgery is the patient-specific spring selection. The selection of spring force depends on the suture involved, subtypes of sagittal CSO, and age of the infant, among other factors. Clinically, physicians manually judge the subtype of sagittal CSO patients based on their CT image data, which may cause bias from different clinicians. An objective system would be helpful to stratify the sagittal CSO patients and make spring choice less subjective.

METHODS

The authors developed a novel informatics system to automatically segment and characterize sutures and classify sagittal CSO. The proposed system is composed of three phases: preprocessing, sutures segmentation, and classification. First, the three-dimensional (3D) skull was extracted from the CT images and aligned with the symmetry of the cranial vault. Second, a "hemispherical projection" algorithm was developed to transform 3D surface of the skull to a polar two-dimensional plane. Through the transformation, an "effective" projected region can be obtained to enable easy segmentation of sutures. Then, the different types of sutures, such as coronal sutures, lambdoid sutures, sagittal suture, and metopic suture, obtained from the segmented sutures were further identified by a dual-projection technique of the midline of the sutures. Finally, 108 quantified features of sutures were extracted and selected by a proposed multiclass feature scoring system. The sagittal CSO patients were classified into four subtypes: anterior, central, posterior, and complex with the support vector machine approach. Fivefold cross validation (CV) was employed to evaluate the capability of selected features in discriminating the four subtypes in 33 sagittal CSO patients. Receiver operating characteristics (ROC) curves were used to assess the robustness of the developed system.

RESULTS

The segmentation results of the proposed method were clinically acceptable for the qualitative evaluation. For the quantitative evaluation, the fivefold CV accuracy of the classification for the four subtypes was 72.7%. This classification system was reliable with the area under curve (in ROC analysis) being greater than 0.8 for four two-class problems.

CONCLUSIONS

The proposed hemispherical projection algorithm based on backtracking search can successfully segment sutures of the cranial vault. The classification system can also offer a desirable performance. As a result, the proposed segmentation and classification system is expected to bring insights into clinic research and the selection of the spring force to facilitate widespread application of this minimally invasive treatment.

Revisiting Crouzon syndrome: reviewing the background and management of a multifaceted disease

PURPOSE

Crouzon syndrome is a complex craniosynostosis of autosomal dominant transfer, with a highly variable phenotypic appearance. Some patients are afflicted with a mild form of the disease and able to live a fully functional lifestyle, whereas many patients suffer from a severe form of the disease causing a significant impact on their quality of life. Although several case reports and genetic studies have been performed, there has been no recent review of the literature to collate the information on this disorder. In this paper, we seek to unify the findings of this disorder to provide the pediatric provider with a succinct, but complete discussion of this disease.

METHODS

Articles from 1994 to 2014 were queried on PubMed and reviewed for utility by all three researchers involved in the project. Further literature review was done on relevant articles found within references of selected articles.

RESULTS

Crouzon syndrome, although of variable penetrance, is thought to be caused in part by a mutation in the fibroblast growth factor receptor-2 (FGFR2) on chromosome 10. Aside from craniofacial malformations, the disease can also cause hearing loss and airway challenges due to malformations in the nasal cavity and nasopharyngeal airway. Management options from the perspective of the otorhinolaryngologist are diverse and revolve around craniosynostectomy, offsetting midfacial hypoplasia, addressing obstructive sleep apnea and a compromised airway, psychosocial and esthetic interventions, and ultimately requiring a multidisciplinary team approach.

CONCLUSION

Mutations in the FGFR2 are responsible for 50 % of mutations within this multifaceted syndrome. Crouzon syndrome is an autosomal dominant disorder with a number of distinguishing characteristics, including craniosynostosis, maxillary hypoplasia, exophthalmos, and multiple other features. Early intervention, both medically and surgically, as well as disciplined follow-up with the pediatric provider are crucial to the management of this disorder. In particular, management should address cranial suture release, midfacial advancement, evaluation for hearing deficits, and obstructive sleep apnea, with expedient intervention for airway compromise and increased intracranial pressure.

Cephalic index in the evaluation of surgical treatment of children with sagittal synostosis. Preliminary report

AIM OF THE STUDY

To analyze changes of the cephalic index (CI) values in patients with sagittal synostosis operated on in the Department of Surgery of Children and Adolescents of the Institute of Mother and Child in Warsaw.

MATERIAL AND METHODS

The study group consisted of 14 consecutive cases (11 boys and 3 girls). In 8 patients younger than 3 months of age (1st subgroup) the modified reversed-pi technique (craniotomy in the shape of the reversed Greek π letter) was utilized. In 6 older infants and in patients with severe head deformity - the radical cranial vault reconstructions were performed (2nd subgroup). The statistical analysis of the preoperative (preop) and postoperative (postop) cephalic index (CI) values was done.

RESULTS

For the entire study group the preop CI values ranged from 61 to 77 (mean 68.14, median 68.5) and postop CIs from 73 to 89 (mean 77.64, median 76). In the 1st subgroup the preop CIs ranged from 63 to 77 (mean 69.625, median 69) whereas the postop CIs from 69 to 89 (mean 78.125, median 76.5). In the 2nd subgroup the preop CI values ranged from 61 to 72 (mean 66.1667, median 66) and postop from 73 to 81 (mean 77, median 77). All the differences were statistically significant.

CONCLUSION

The values of cephalic index increased after both types of procedures. It signifies the correction of dolichocephaly in both subgroups of the patients. However, because of the small number of operated children, further studies are necessary.

Biomechanical evaluation of sagittal maxillary internal distraction osteogenesis in unilateral cleft lip and palate patient and noncleft patients: a three-dimensional finite element analysis

OBJECTIVE

To compare the pattern and amount of stress and displacement during maxillary sagittal distraction osteogenesis (DO) between a patient with unilateral cleft lip and palate (UCLP) and a noncleft patient.

MATERIALS AND METHODS

Three-dimensional finite element models for both skulls were constructed. Displacements of the surface landmarks and stress distributions in the circummaxillary sutures were analyzed after an anterior displacement of 6 mm was loaded to the elements where the inferior plates of the distractor were assumed to be fixed and were below the Le Fort I osteotomy line.

RESULTS

In sagittal plane, more forward movement was found on the noncleft side in the UCLP model (-6.401 mm on cleft side and -6.651 mm on noncleft side for the central incisor region). However, similar amounts of forward movement were seen in the control model. In the vertical plane, a clockwise rotation occurred in the UCLP model, whereas a counterclockwise rotation was seen in the control model. The mathematical UCLP model also showed higher stress values on the sutura nasomaxillaris, frontonasalis, and zygomatiomaxillaris on the cleft side than on the normal side.

CONCLUSIONS

Not only did the sagittal distraction forces produce advancement forces at the intermaxillary sutures, but more stress was also present on the sutura nasomaxillaris, sutura frontonasalis, and sutura zygomaticomaxillaris on the cleft side than on the noncleft side.

Rapid re-synostosis following suturectomy in pediatric mice is age and location dependent

Craniosynostosis is the premature fusion of the cranial sutures early in development. If left untreated, craniosynostosis can lead to complications resulting from cranial deformities or increased intracranial pressure. The standard treatment involves calvarial reconstruction, which in many cases undergoes rapid re-synostosis. This requires additional surgical intervention that is associated with a high incidence of life threatening complications. To better understand this rapid healing, a pediatric mouse model of re-synostosis was developed and characterized. Defects (1.5mm by 2.5mm) over the posterior frontal suture were created surgically in weanling (21 days post-natal) and adolescent (50 days post-natal) C57Bl/6J mice. In addition, defects were created in the frontal bone lateral to the posterior frontal suture. The regeneration of bone in the defect was assessed using advanced image processing algorithms on micro-computed tomography scans. The genes associated with defect healing were assessed by real-time PCR of mRNA isolated from the tissue present in the defect. The results showed that the weanling mouse healed in a biphasic process with bone bridging the defect by post-operative (post-op) day 3 followed by an increase in the bone volume on day 14. In adolescent mice, there was a delay in bone bridging across the defect, and no subsequent increase in bone volume. No bridging of the defect by 14 days post-op was seen in identically sized defects placed lateral to the suture in both weanling and adolescent animals. This study demonstrates that bone regeneration in the cranium is both age and location dependent. Rapid and robust bone regeneration only occurred when the defect was created over the posterior frontal suture in immature weanling mice.

Craniosynostosis and deformational plagiocephaly: when and how to intervene

Craniosynostosis, a congenital deformity in which one or more of the sutures between the bones of the cranial vault fuse prematurely, is a relatively rare condition that is usually obvious just after birth. Deformational plagiocephaly is much more common and usually becomes apparent by 2 months of age. Although the head of a baby with deformational plagiocephaly may appear flat on one side, deformational plagiocephaly does not affect brain function. Craniosynostosis, however, may impair brain growth and development and, thus, is far more serious. Babies with irregularly shaped heads that are concerning should be evaluated by a craniofacial surgeon. This article provides an overview of the physical signs of craniosynostosis and deformational plagiocephaly as well as an update on treatment.

Correlations between the abnormal development of the skull base and facial skeleton growth in anterior synostotic plagiocephaly: the predictive value of a classification based on CT scan examination

BACKGROUND

Anterior cranial plagiocephaly, depending on the early hemicoronal suture fusion, is the most relevant form of plagiocephaly in terms of clinical implications. Its estimated incidence ranges between 0.4 and 1 per 1,000 live births. In the present report, we aim at validating the classification of Di Rocco and Velardi, proposing a scheme based on basicranium analysis using CT scans and its predictive value by evaluating the developmental characteristics of a population of adult subjects affected by anterior plagiocephaly who had underwent the surgical correction in the first months of life.

MATERIALS AND METHODS

The group of patients here considered was retrieved from among all patients operated upon for craniostenosis in the pediatric neurosurgery unit of Policlinico Gemelli in Rome between January 1, 1980 and December 31, 1989. The study group consisted of 13 patients, seven females and six males, affected by anterior synostotic plagiocephaly ranging in age between 20 and 32 years (mean 25.54 years). We also formed a group of unaffected patients in order to control for normal variability in the population. The subjects of the study group were evaluated using CT scan exams and cephalometric analyses were performed using three-dimensional reconstruction.

DISCUSSION AND CONCLUSION

In this study, we were able to associate a facial phenotype to confirm the predictive value of the classification proposed. It is highly probable that the different outcomes depend on the different degrees of involvement in the synostotic process by the various skull base sutures which were essentially unaffected by the surgical procedures.

Morphological analysis of the skull shape in craniosynostosis

Craniosynostosis represents premature suture fusion of the fetal and neonatal skull. Pathogenesis of craniosynostosis is complex and probably multifactorial. Growth of skull bones is strictly connected with the expanding growth of the brain and cranial malformations or prematurely fused sutures cause abnormal head shape. In order to diagnose the craniosynostosis, physical examination, plain radiography, and computed tomography with 3D reconstructions are indispensable. Engineering software such as Mimics v.13.1 and 3-matic v.5.0 enables a 3-dimensional model of head to be generated, based on the pictures obtained from CT. It is also possible to indicate the distances between the characteristic anatomical points. These measures are helpful during planning the neurosurgical correction of the skull, because the possibility of strictly specifing incisions before surgery, which is very important to provide the maximal safety of a child.