Cephalic index in the first three years of life: study of children with normal brain development based on computed tomography

Machine learning applications in craniosynostosis diagnosis and treatment prediction: a systematic review

Craniosynostosis refers to the premature fusion of one or more of the fibrous cranial sutures connecting the bones of the skull. Machine learning (ML) is an emerging technology and its application to craniosynostosis detection and management is underexplored. This systematic review aims to evaluate the application of ML techniques in the diagnosis, severity assessment, and predictive modeling of craniosynostosis. A comprehensive search was conducted on the PubMed and Google Scholar databases using predefined keywords related to craniosynostosis and ML. Inclusion criteria encompassed peer-reviewed studies in English that investigated ML algorithms in craniosynostosis diagnosis, severity assessment, or treatment outcome prediction. Three independent reviewers screened the search results, performed full-text assessments, and extracted data from selected studies using a standardized form. Thirteen studies met the inclusion criteria and were included in the review. Of the thirteen papers examined on the application of ML to the identification and treatment of craniosynostosis, two papers were dedicated to sagittal craniosynostosis, five papers utilized several different types of craniosynostosis in the training and testing of their ML models, and six papers were dedicated to metopic craniosynostosis. ML models demonstrated high accuracy in identifying different types of craniosynostosis and objectively quantifying severity using innovative metrics such as metopic severity score and cranial morphology deviation. The findings highlight the significant strides made in utilizing ML techniques for craniosynostosis diagnosis, severity assessment, and predictive modeling. Predictive modeling of treatment outcomes following surgical interventions showed promising results, aiding in personalized treatment strategies. Despite methodological diversities among studies, the collective evidence underscores ML's transformative potential in revolutionizing craniosynostosis management.

Establishment of Cephalic Index by Computed Tomography in Sampled Chinese Children

OBJECTIVE

Cephalic Index (CI), the ratio of head width to length, is one of the indexes reflecting cranial morphological characteristics. Current norms were established by European and American countries. The purpose of the study was to study anthropometry of cranial parameters using computed tomography scans to establish the CI of the sampled Chinese Children.

METHODS

The cross-sectional study was carried out on patients of age younger than 14 years old at Shanghai Children's Medical Center. The measurement of maximum cranial breadth and maximum cranial length were taken on a computed tomography scan machine and recorded for analysis. Cephalic Index was calculated for each age and sex group and compared with previously established norms.

RESULTS

Five hundred eighteen patients met the inclusion criteria, including 301 males and 217 females. The means for boys and girls were 87.1 (SD: 4.3) and 85.8 (SD: 4.3), respectively. There was a significant difference between boys and girls (P < 0.01). Cephalic Index in different ages and on applying the 1-way analysis of variance association was statistically insignificant (P = 0.19).

CONCLUSIONS

Chinese head shape was brachycephalic. A statistically significant correlation was seen between the CI and sex, while not age.

Long-term results of minimally invasive strip craniectomy without helmet therapy for scaphocephaly - a single-centre experience

Scaphocephaly is the most common type of craniosynostosis and various surgical techniques are used for treatment. Due to late postoperative changes of the head shape, long-term outcome data is important for evaluating any new surgical technique. At our institution, minimally invasive strip craniectomy without regular helmet therapy is the standard treatment in scaphocephalic patients. Between October 2021 and February 2023, we retrospectively examined the skull shape of patients who underwent minimally invasive strip craniectomy for scaphocephaly using a 3D surface scan technique. The cephalic index (CI), the need for helmet therapy and additional cosmetic outcome parameters were investigated. We included 70 patients (72.5% male). The mean follow-up time was 46 (10-125) months and the mean CI was 75.7 (66.7-85.2). In 58 patients, the final cosmetic result was rated as "excellent/good" (mean CI: 76.3; 70.4-85.0), in 11 as "intermediate" (mean CI: 73.3; 66.7-77.6), and in one case as "unsatisfactory" (CI 69.3). The presence of a suboccipital protrusion was associated with a "less than good" outcome. The CI correlated significantly with the overall outcome, the presence of frontal bossing, and the interval between scan and surgery (age at scan). Minimally invasive strip craniectomy is an elegant and safe method to correct scaphocephaly. Our data show good cosmetic results in the long term even without regular postoperative helmet therapy.

Characterization of cranial growth patterns using craniometric parameters and best-fit logarithmic growth curves

Few studies have reported a complete quantitative database of cranial growth, from infancy to adulthood, as a reference through three-dimensional analysis. Our study aimed to characterize cranial growth patterns using craniometric parameters by establishing sex- and age-specific norms. In total, 1009 Korean patients (male-to-female ratio, 2:1; age range, 0-18 years) who underwent thin-slice computed tomography (CT) scans for head trauma were divided into 20 age groups, with a 6-month interval for those under 2 years and a 1-year interval for those over 2 years. After four reference planes [Frankfurt horizontal (FH), midsagittal, and two coronal planes passing the sella (S) and basion (B)] had been established, intracranial volume (ICV), anteroposterior diameter (APD), biparietal diameter (BPD), cranial heights (CHs), cephalic index (CI, BPD/APD), and height index (HI, CH-B/APD) were measured using Mimics software. Best-fit logarithmic curves were derived using a linear regression model. The best-fit curves for ICV (cm3) were y = 785.6 + 157*ln(age) for males (R2 = 0.5752) and y = 702 + 150.5*ln(age) for females (R2 = 0.6517). After adjustment for age, males had higher values of ICV, APD, BPD, and CHs than females (all p < 0.0001). ICV, APD, BPD, and CHs demonstrated a rapid increase during the first few months of life, reaching 90-95% of the adult size by 5-6 years of age, while CI and HI showed a continuous decline by 4%, regardless of sex. This study presented cranial growth references for more than 1000 of the Korean population aged up to 18 years. This might help to provide guidelines for diagnosis and treatment (including timing, amount, and direction) for cranial reconstruction in pediatric patients with craniosynostosis.

Human genetics and molecular genomics of Chiari malformation type 1

Chiari malformation type 1 (CM1) is the most common structural brain disorder involving the craniocervical junction, characterized by caudal displacement of the cerebellar tonsils below the foramen magnum into the spinal canal. Despite the heterogeneity of CM1, its poorly understood patho-etiology has led to a 'one-size-fits-all' surgical approach, with predictably high rates of morbidity and treatment failure. In this review we present multiplex CM1 families, associated Mendelian syndromes, and candidate genes from recent whole exome sequencing (WES) and other genetic studies that suggest a significant genetic contribution from inherited and de novo germline variants impacting transcription regulation, craniovertebral osteogenesis, and embryonic developmental signaling. We suggest that more extensive WES may identify clinically relevant, genetically defined CM1 subtypes distinguished by unique neuroradiographic and neurophysiological endophenotypes.

Comparative Analysis of 2D and 3D Metrics for Evaluation of Postoperative Outcomes Following Endoscopic Suturectomy for Sagittal Craniosynostosis

To assess whether 3-dimensional (3D) volumetrics can be used to track and evaluate postoperative course of patients treated with endoscopic suturectomy for nonsyndromic sagittal synostosis, we compared changes in 2-dimensional (2D) measurements along with 3D volumetric correlates throughout the period of helmet therapy. Forty-six patients treated at our institution with endoscopic suturectomy for sagittal synostosis were retrospectively reviewed. Head circumference (HC), cephalic index (CI), and total cranial volumes (TCVs) were measured at 3 timepoints following surgery using optical surface scans obtained for helmet orthotics. All measurements showed significant differences between timepoints on the analysis of variance ( P <0.001). There was a significant correlation between CI and TCV (r=0.35, P =0.004) and between HC and TCV (r=0.81, P <0.001). The normalized rate of change over the course of treatment was significantly higher for TCV (36.7%) than for CI (8.8%) and HC (8.4%, P <0.001), with no difference between HC and CI. The authors conclude that 3D metrics were able to reliably follow the course of postoperative 2D metrics. There was a direct and linear correlation between HC and CI with TCV. Total cranial volumes showed the highest rate of sustained change at every timepoint. Although CI and HC plateau after the first measurement, TCV continues to adapt over the course of treatment. These results demonstrate the feasibility and value of volumetrics from 3D imaging to provide a more comprehensive evaluation of postoperative surgical outcomes than traditional 2D metrics without the ionizing radiation traditionally utilized for CT to obtain 3D metrics.

Gahvora cradling in Tajikistan: Cultural practices and associations with motor development

In Tajikistan, infants are bound supine in a "gahvora" cradle that severely restricts movement. Does cradling affect motor development and body growth? In three studies (2013-2018), we investigated associations between time in the gahvora (within days and across age) and motor skills and flattened head dimensions in 8-24-month-old Tajik infants (N = 269, 133 girls, 136 boys)) and 4.3-5.1-year-old children (N = 91, 53 girls, 38 boys). Infants had later motor onset ages relative to World Health Organization standards and pronounced brachycephaly; cradling predicted walk onset age and the proficiency of sitting, crawling, and walking. By 4-5 years, children's motor skills were comparable with US norms. Cultural differences in early experiences offer a unique lens onto developmental processes and equifinality in development.

Comparison of molding helmet therapy versus natural course in twins with nonsynostotic head deformation

This observational study aims to compare the effectiveness of helmet therapy versus natural course in twin siblings suffering from nonsynostotic head deformations. A retrospective analysis of all twin couples treated with helmet therapy between March 2009 and May 2017 at an orthopedic hospital was conducted. Inclusion criteria were me if only one twin received helmet therapy. The other twin acted as control. A classification for different head shapes was used. A total of 61 twin couples was included. Change in outcome parameters of helmet therapy and natural course differed significantly: cranial vault asymmetry (CVA) -0.66 cm vs. -0.04 cm, cranial vault asymmetry index (CVAI) -5.35% vs. -0.51% (both p < 0.001), cephalic index (CI) -3.10% vs. -1.91% (p = 0.006). Helmet therapy showed a success rate (CI < 90% and CVAI ≤7% or better) of 63.6% vs. 21.1% in children with natural course (p = 0.002). Within the limitations of the study it seems that the results of this retrospective, single-center study confirm that helmet therapy to be a reliable treatment for mild to severe positional head deformation.

Evaluating Cranial Growth in Japanese Infants Using a Three-dimensional Scanner: Relationship between Growth-related Parameters and Deformational Plagiocephaly

In this study, we aimed to evaluate the longitudinal changes in the cranial shape of healthy Japanese infants using a three-dimensional scanner and construct a normal values database for the growth process. Preterm infants (gestational age < 37 weeks), infants with neonatal asphyxia (5-minute Apgar score of <7), and patients who started helmet therapy for deformational plagiocephaly were excluded from this study. The first scan was performed at approximately 1 month of age, followed by two scans conducted at 3 and 6 months of age. The parameters considered were as follows: cranial length, width, height, circumference, volume, cranial vault asymmetry index, and cephalic index. A cranial vault asymmetry index >5% was defined as deformational plagiocephaly. Changes in each parameter were examined using repeated-measures analysis of variance classified by sex and deformational plagiocephaly status. The rate of increase in each parameter was also examined. In total, 88 infants (45 boys and 43 girls) were included in this study. All growth-related parameters were noted to increase linearly with time. Sex differences were observed in all parameters except cranial length. Deformational plagiocephaly was found to have no effect on growth-related parameters. Cranial volume increased by 60% from 1 to 6 months of age. The growth almost uniformly influenced the rate of increase in volume in each coordinate axis direction. Overall, the mean trends in three-dimensional parameters in infants up to 6 months of age were obtained using a three-dimensional scanner. These trends could be used as a guide by medical professionals involved in cranioplasty.

Data-driven Normative Reference of Pediatric Cranial Bone Development

Available normative references of cranial bone development and suture fusion are incomplete or based on simplified assumptions due to the lack of large datasets. We present a fully data-driven normative model that represents the age- and sex-specific variability of bone shape, thickness, and density between birth and 10 years of age at every location of the calvaria.

A Computational Framework to Predict Calvarial Growth: Optimising Management of Sagittal Craniosynostosis

The neonate skull consists of several bony plates, connected by fibrous soft tissue called sutures. Premature fusion of sutures is a medical condition known as craniosynostosis. Sagittal synostosis, caused by premature fusion of the sagittal suture, is the most common form of this condition. The optimum management of this condition is an ongoing debate in the craniofacial community while aspects of the biomechanics and mechanobiology are not well understood. Here, we describe a computational framework that enables us to predict and compare the calvarial growth following different reconstruction techniques for the management of sagittal synostosis. Our results demonstrate how different reconstruction techniques interact with the increasing intracranial volume. The framework proposed here can be used to inform optimum management of different forms of craniosynostosis, minimising the risk of functional consequences and secondary surgery.

Growth Curves for Intracranial Volume and Two-dimensional Parameters for Japanese Children without Cranial Abnormality: Toward Treatment of Craniosynostosis

In the management of patients with craniosynostosis, it is important to understand growth curve of the normal cranium. Although three-dimensional (3D) computed tomography (CT) images taken in thin slices are easily available nowadays, data on the growth curves of intracranial volume (ICV), cranial length, cranial width, and cranial height in the normal cranium are mainly based on older studies using radiography, and there are insufficient reports using CT images especially taken in thin slices. The purpose of this study was to establish growth curves in the normal cranium of Japanese children using thin-slice images. Cranial images of 106 subjects (57 males, 49 females; aged 0-83 months) without significant cranial abnormalities were retrospectively analyzed. Using thin-slice CT images, the ICV and two-dimensional parameters such as cranial length, cranial width, and cranial height were measured by iPlan, followed by generating growth curves and calculating cephalic index (CI). ICV calculated from thin-slice CT images was compared with that obtained by substituting two-dimensional parameters into Mackinnon formula. The ICV growth curves for males and females were similar in shape. As with the ICV, the two-dimensional parameters increased most rapidly in the first year after birth. There was no significant difference in CI between the sexes or among any age groups. ICV calculated from thin-slice 3D CT images was 60% of that obtained from Mackinnon formula. These data will enable us to compare these specific measurements in craniosynostosis patients directly with those of normal children, which will hopefully help in managing these patients.

Predictive Statistical Model of Early Cranial Development

OBJECTIVE

We present a data-driven method to build a spatiotemporal statistical shape model predictive of normal cranial growth from birth to the age of 2 years.

METHODS

The model was constructed using a normative cross-sectional computed tomography image dataset of 278 subjects. First, we propose a new standard representation of the calvaria using spherical maps to establish anatomical correspondences between subjects at the cranial sutures - the main areas of cranial bone expansion. Then, we model the cranial bone shape as a bilinear function of two factors: inter-subject anatomical variability and temporal growth. We estimate these factors using principal component analysis on the spatial and temporal dimensions, using a novel coarse-to-fine temporal multi-resolution approach to mitigate the lack of longitudinal images of the same patient.

RESULTS

Our model achieved an accuracy of 1.54 ± 1.05 mm predicting development on an independent longitudinal dataset. We also used the model to calculate the cranial volume, cephalic index and cranial bone surface changes during the first two years of age, which were in agreement with clinical observations.

SIGNIFICANCE

To our knowledge, this is the first data-driven and personalized predictive model of cranial bone shape development during infancy and it can serve as a baseline to study abnormal growth patterns in the population.

Reference Values for Cranial Morphology Based on Three-dimensional Scan Analysis in 1-month-old Healthy Infants in Japan

Currently, molded helmet therapy is used to treat infants with deformational plagiocephaly. However, the indices of normal cranial shape remain unclear, and thus, the prevalence of deformational plagiocephaly is unknown, particularly in Japan. We investigated the reference values for cranial morphological characteristics in 1-month-old Japanese infants using a three-dimensional scanner, to determine the prevalence of deformational plagiocephaly. One hundred fifty-three healthy infants who visited three hospitals (from April 2020 to March 2021) were enrolled. Cranial shape was measured using a three-dimensional scanner and was analyzed using image analysis software. Outcome measures were cranial volume, length, width, length-width ratio, circumference, asymmetry, and vault asymmetry index; cephalic index; and anterior, posterior, and overall symmetry ratios. The cranial vault asymmetry index >3.5% or ≥10% were diagnosed as deformational or severe deformational plagiocephaly, respectively. The mean age at measurement was 35.7 days. The mean cranial volume was 559 mL; cranial length, 129 mm; cranial width, 110 mm; length-width ratio, 118%; cephalic index, 85.2%; cranial circumference, 377 mm, cranial asymmetry, 6.4 mm; cranial vault asymmetry index, 5.0%; and anterior, posterior, and overall asymmetry ratios, 93.1%, 91.3%, and 96.4%, respectively. The prevalence of deformational and severe deformational plagiocephaly was 64.7% and 6.6%, respectively. Sex-based differences were observed for cranial volume and width. The results obtained in this study can be considered standard values that can facilitate the differentiation of abnormal infant cranial morphological characteristics for Japanese medical practitioners.

Comparisons of Intracranial Volume and Cephalic Index After Correction of Sagittal Craniosynostosis With Either Two or Three Springs

ABSTRACT

In this retrospective study, the authors determined changes in intracranial volume (ICV) and cephalic index (CI) in patients with sagittal craniosynostosis and operated with craniotomy combined with either 2 or 3 springs. The authors included patients (n = 112) with complete follow-up that had undergone surgical correction for isolated sagittal craniosynostosis with craniotomy combined with springs between 2008 and 2017. All patients underwent computed tomography examination preoperative, at the time of spring extraction, and at 3 years of age. Intracranial volume was measured using a semiautomatic MATLAB program, and CI was calculated as the width/length of the skull. The authors found that craniotomy combined with 2 springs increased the ICV from a preoperative value of 792 ± 113 mL (mean ± standard deviation) to 1298 ± 181 mL at 3 years of age and increased the CI from 72.1 ± 4.1 to 74.6 ± 4.3, whereas craniotomy combined with 3 springs increased the ICV from 779 ± 128 mL to 1283 ± 136 mL and the CI from 70.7 ± 4.3 to 74.8 ± 3.7. The relative increase in ICV was 65 ± 21% in the two-spring group and 68 ± 34% in the three-spring group (P value = 0.559), and the relative increase in CI was 3.6 ± 3.3% in the two-spring group as compared with 6.0 ± 5.0% in the three-spring group (P = 0.004). These findings demonstrated that use of 3 springs resulted in additional absolute and relative CI-specific effects as compared with 2 springs during the time when the springs were in place, with this effect maintained at 3 years of age.

Postoperative helmet therapy following fronto-orbital advancement and cranial vault remodeling in patients with unilateral coronal synostosis

Out of all the synostotic corrective surgeries, fronto-orbital advancement and cranial vault remodeling for patients with unilateral coronal synostosis is one of the hardest to maintain symmetric and proportional correction without some amount of relapse. Over the course of 20 years operating on these patients, the senior author has made multiple adjustments to compensate for relapse asymmetry, including overcorrection on the affected side, increased points of fixation, periosteal release, and scalp expansion with galeal scoring to minimize tension of the closure. As a result of these interventions, we have seen improved immediate results following surgery. However, we have continued to note clinically significant relapse postoperatively. As such, we have started to implement postoperative helmet therapy (PHT) to help maintain the surgical correction, improve secondary brachycephaly, and increase overall symmetry. PHT is a reasonable low-risk complement to fronto-orbital advancement and cranial vault remolding. Clinically, PHT appears to help minimize relapse and improve overall head symmetry. Further investigation and increased patient enrollment are required to determine the true benefits of PHT in this patient population.

Rethinking Farkas: Updating Cephalic Index Norms in a Large, Diverse Population

BACKGROUND

Cephalic index, the ratio of head width to length, is one normative indicator used by insurers to derive criteria for plagiocephaly helmet authorization. Current norms were established by a small sample of white children in the 1987 Farkas and Munro data set. This study establishes updated cephalic index values for infants and children in a large, diverse patient population.

METHODS

Children aged 0 to 3 months, 3 to 6 months, 9 to 12 months, 2 to 3 years, and 12 to 14 years were recruited at their well-child appointment. Cephalic index was calculated for each age group and compared to previously established norms.

RESULTS

Eight hundred seventy patients met inclusion criteria. The means for boys and girls between 0 and 6 months were 83.5 (n = 155, SD 6.01) and 83.5 (n = 191, SD 5.80), respectively. Established means for boys and girls between 0 and 6 months were 74.4 (n = 38, SD 5.2) and 74.3 (n = 49, SD 6.1), respectively. The difference between norms is highly statistically significant (p < 0.0001). For this age range, insurance criteria for a helmet is >83.7 for boys and >82.7 for girls. Using previous norms, 74 boys (44.6 percent) and 104 girls (54.5 percent) would meet criteria for a helmet under current guidelines.

CONCLUSIONS

The mean cephalic index of children has changed. The reasons could include diversifying populations in the United States and the introduction of the Back to Sleep campaign. Over 50 percent of children may inappropriately meet criteria for a helmet based on prior norms. Updating norms could change the definition of plagiocephaly for a helmet orthosis.

Cephalic Index of Korean Children With Normal Brain Development During the First 7 Years of Life Based on Computed Tomography

Objective

To identify the normal range, distribution, and age-dependent differences in the cephalic index (CI) of Korean children with normal brain development and develop a classification of the current CI for Korean children up to 7 years of age.

Methods

We retrospectively analyzed 1,389 children who visited our hospital in the emergency room between October 2015 and September 2020 because of suspected head injuries. Finally, 1,248 children (741 male and 507 female) were enrolled after excluding abnormal medical or familial history and divided into 10 groups by age. The CI was measured using brain computed tomography and calculated according to the following equation: cephalic width/cephalic length×100.

Results

The averages of CI by age groups were as follows: 89.29 (0–3 months group, n=44); 91.41 (4–6 months group, n=63); 89.68 (7–9 months group, n=62); 87.52 (10–12 months group, n=41); 87.64 (≥2 years group, n=243); 86.63 (≥3 years group, n=178); 85.62 (≥4 years group, n=232); 85.77 (≥5 years group, n=201); 85.15 (≥6 years group, n=75); and 85.34 (≥7 years group, n=109). The CI of Korean children in normal brain development was confirmed to be large, showing a notable difference compared to that of Caucasians.

Conclusion

The current CI of Korean children will provide a valuable reference for diagnosing and treating cranial deformities, especially dolichocephaly and brachycephaly as well as to monitor the morphology of the cranium in clinics.

Improved cephalic index following early cranial vault remodeling in patients with isolated nonsyndromic sagittal synostosis

OBJECTIVE

Isolated nonsyndromic sagittal synostosis (SS) is the most common form of craniosynostosis in children, accounting for approximately 60% of all craniosynostoses. The typical cranial measurement used to define and follow SS is the cephalic index (CI). Several surgical techniques have been suggested, but agreement on type and timing of surgery is lacking. This study aimed to evaluate the authors' institutional experience of surgically treating SS using a modified subtotal cranial vault remodeling technique in a population-based cohort. Special attention was directed toward the effect of patient age at time of surgery on long-term CI outcome.

METHODS

A retrospective analysis was conducted on all patients with isolated nonsyndromic SS who were surgically treated from 2003 to 2011. Data from electronic medical records were gathered. Eighty-two patients with SS were identified, 77 fulfilled inclusion criteria, and 72 had sufficient follow-up data and were included. CI during follow-up after surgery was investigated with ANOVA and a linear mixed model.

RESULTS

In total, 72 patients were analyzed, consisting of 16 females (22%) and 56 males (78%). The mean ± SD age at surgery was 4.1 ± 3.1 months. Blood transfusions were received by 81% of patients (26% intraoperatively, 64% postoperatively, 9% both). The mean ± SD time in the pediatric ICU was 1.1 ± 0.25 days, and the mean ± SD total hospital length of stay was 4.6 ± 2.0 days. No patient required reoperation. The mean ± SD CI increased from 69 ± 3 to 87 ± 5 for patients who underwent surgery before 45 days of age. Surgery resulted in a larger increase in CI for patients who underwent surgery at a younger age compared with older patients (p < 0.05, Tukey's HSD test). In the comparison of patients who underwent surgery before 45 days of age with patients who underwent surgery at 45-90, 90-180, and more than 180 days of age, the linear mixed model estimated a long-term loss of CI of 3.0, 5.5, and 7.4 points, respectively.

CONCLUSIONS

The modified subtotal cranial vault remodeling technique used in this study significantly improved CI in patients with SS. The best results were achieved when surgery was performed early in life.

Study of the growth and shape of the brain and cranial base during the first two years of life

Ontogeny of the cranial base and the brain integrates data on growth, maturation and ontogenetic allometry of these two systems in the course of development. The aim of our work was to study the ontogeny of the cranial base and the brain in order to understand their growth dynamic and shape changes using a traditional morphometric approach in individuals with normal (non-pathological) development.

MATERIEL AND METHOD

Forty-seven infants having been included in the unexpected infant death french protocol were analyzed. Medical imaging (CT and MRI) exams, followed by an autopsy and pathology examination allowed us to include only infants free from brain disease or pathology affecting growth.

RESULTS

Testing of measurement reliability validated 12 distances and 3 angles as well as the positioning of the landmarks that had been used to obtain the distances and the angles. No correlation between sex and the various variables studied was found. However, a correlation was observed between these variables and age, making it possible to propose a growth curve. A medium to strong correlation was found between brain variables and the bone variables of the cranial base, underlining the parallel development of the two systems.

CONCLUSION

Our study, carried out in a rigorously selected population of infants, presents a fundamental approach to the study of ontogenesis.

Pediatric cranial deformations: demographic associations

OBJECTIVE

No study has established a relationship between cranial deformations and demographic factors. While the connection between the Back to Sleep campaign and cranial deformation has been outlined, considerations toward cultural or anthropological differences should also be investigated.

METHODS

The authors conducted a retrospective review of 1499 patients (age range 2 months to less than 19 years) who presented for possible trauma in 2018 and had a negative CT scan. The cranial vault asymmetry index (CVAI) and cranial index (CI) were used to evaluate potential cranial deformations. The cohort was evaluated for differences between sex, race, and ethnicity among 1) all patients and 2) patients within the clinical treatment window (2-24 months of age). Patients categorized as "other" and those for whom data were missing were excluded from analysis.

RESULTS

In the CVAI cohort with available data (n = 1499, although data were missing for each variable), 800 (56.7%) of 1411 patients were male, 1024 (79%) of 1304 patients were Caucasian, 253 (19.4%) of 1304 patients were African American, and 127 (10.3%) of 1236 patients were of Hispanic/Latin American descent. The mean CVAI values were significantly different between sex (p < 0.001) and race (p < 0.001). However, only race was associated with differences in positional posterior plagiocephaly (PPP) diagnosis (p < 0.001). There was no significant difference in CVAI measurements for ethnicity (p = 0.968). Of the 520 patients in the treatment window cohort, 307 (59%) were male. Of the 421 patients with data for race, 334 were Caucasian and 80 were African American; 47 of the 483 patients with ethnicity data were of Hispanic/Latin American descent. There were no differences between mean CVAI values for sex (p = 0.404) or ethnicity (p = 0.600). There were significant differences between the mean CVAI values for Caucasian and African American patients (p < 0.001) and rate of PPP diagnosis (p = 0.02). In the CI cohort with available data (n = 1429, although data were missing for each variable), 849 (56.8%) of 1494 patients were male, 1007 (67.4%) of 1283 were Caucasian, 248 (16.6%) of 1283 were African American, and 138 patients with ethnicity data (n = 1320) of Hispanic/Latin American descent. Within the clinical treatment window cohort with available data, 373 (59.2%) of 630 patients were male, 403 were Caucasian (81.9%), 84 were African American (17.1%), and 55 (10.5%) of 528 patients were of Hispanic/Latin American descent. The mean CI values were not significantly different between sexes (p = 0.450) in either cohort. However, there were significant differences between CI measurements for Caucasian and African American patients (p < 0.001) as well as patients of Hispanic/Latin American descent (p < 0.001) in both cohorts.

CONCLUSIONS

The authors found no significant associations between cranial deformations and sex. However, significant differences exist between Caucasian and African American patients as well as patients with Hispanic/Latin American heritage. These findings suggest cultural or anthropological influences on defining skull deformations. Further investigation into the factors contributing to these differences should be undertaken.

Increased Incidence of Ophthalmologic Findings in Children With Concurrent Isolated Nonsyndromic Metopic Suture Abnormalities and Deformational Cranial Vault Asymmetry

OBJECTIVE

The purpose of this project was to study the incidence of ophthalmologic findings which are known to be risk factors for amblyopia in children who have coexisting metopic suture abnormalities and deformational plagiocephaly (DP) and brachycephaly (DB).

DESIGN

Institutional Review Board-approved retrospective study reviewing records of a consecutive cohort of children under 2 years of age with metopic suture abnormalities and cranial vault asymmetries seen in both the plastic surgery and ophthalmology clinics from 2007 to 2017.

SETTING

Institutional tertiary care center with all care in plastic surgery under the senior author and the standard of care accepted in pediatric ophthalmology under one of two ophthalmologists.

PATIENTS

After application of exclusion criteria, 76 children diagnosed with metopic suture abnormalities and DP/DB were included in the study. Patients with severe trigonocephaly, other suture involvement, syndromic diagnoses, and primary ocular disorders were excluded.

MAIN OUTCOME MEASURES

Describe the incidences of refractive errors (astigmatism, hyperopia, and myopia), anisometropia, strabismus, and amblyopia within the study population.

RESULTS

In our patient population, the rates of amblyopia (17.1%) and strabismus (15.8%) are higher than the general pediatric population rates of 1.5% to 1.8% and 2.4% to 3.6%, respectively. Overall, 47.4% had significant refractive error: 28.9% with astigmatism, 15.8% with hyperopia, 5.3% with myopia, and 10.5% with anisometropia.

CONCLUSIONS

In our patient population, children with coexisting metopic suture abnormalities and DP or DB had significant risk for amblyopia, strabismus, and refractive errors.

Deformational brachycephaly: the clinical utility of the cranial index

OBJECTIVE

The incidence of deformational brachycephaly has risen since the "Back to Sleep" movement in 1992 by the American Academy of Pediatrics. Brachycephaly prevalence and understanding the dynamic nature of the pediatric skull have not been explored in relation to the cranial index (CI). The objective of the study was to determine the prevalence of brachycephaly, via the CI, with respect to time.

METHODS

The authors conducted a retrospective review of 1499 patients ≤ 19 years of age who presented for trauma evaluation with a negative CT scan for trauma (absence of bleed) in 2018. The CI was calculated using CT at the lateral-most point of the parietal bone (cephalic width), and the distance from the glabella to the opisthocranion (cephalic length). Brachycephaly was defined as a CI ≥ 90%.

RESULTS

The mean CI was 82.6, with an average patient age of 6.8 years. The prevalence of deformational brachycephaly steadily decreased from 27% to 4% from birth to > 2 years of life. The mean CI was statistically different between ages < 12 months, 12-24 months, and > 24 months (F[2,1496] = 124.058, p < 0.0005). A simple linear regression was calculated to predict the CI based on age; the CI was found to decrease by 0.038 each month. A significant regression equation was found (F[1,1497] = 296.846, p < 0.0005), with an R2 of 0.140.

CONCLUSIONS

The incidence of deformational brachycephaly is common in infants but decreases as the child progresses through early childhood. Clinicians can expect a significant decrease in mean CI at 12 and 24 months. Additionally, these regression models show that clinicians can expect continued improvement throughout childhood.

Computer-assisted craniometric evaluation for diagnosis and follow-up of craniofacial asymmetries: SymMetric v. 1.0

PURPOSE

The current assessment of patients with craniofacial asymmetries is accomplished by physical examination, anamnesis and radiological imaging. We propose a semi-automated, computer-assisted craniofacial evaluation (SymMetric v 1.0) based on orthogonal photography of the patient's head in 3 positions. The system is simple, low-cost, no-radiation or special resources needed. Although it does not substitute CT in cases of doubt between craniosynostosis and positional plagiocephaly, multiple numeric evaluations indicate regional deformities and severity of the asymmetry, which can help in the clinical decision of indicating or not the orthosis in positional deformities, determining treatment duration or evaluating surgical outcomes after correction.

METHODS

A Matlab-based tool was developed for digital processing of photographs taken in 3 positions (anterior, superior and lateral). The software guides the user to select visible and reproducible landmarks in each photograph acquisition and calculates multiple indexes and metrics, generating a set of comprehensive plots to offer the user an overview of head and facial symmetry across the orthogonal views. For purposes of demonstration, we evaluated 2 patients (one control and one with non-sinostotic deformity).

RESULTS

The results show a clear differentiation of the control and plagiocephalic patient metrics mainly in the superior view, showing potential for diagnosis of the condition, and also detected the clinical improvement during helmet treatment in the follow-up, 3 and 5 months after orthosis' use.

CONCLUSION

We presented a proof-of-concept for a low cost, no radiation evaluation system for craniofacial asymmetries, that can be useful in a clinical context for diagnosis and follow-up of patients.

Modeling the effect of brain growth on cranial bones using finite-element analysis and geometric morphometrics

PURPOSE

Brain expansion during ontogeny has been identified as a key factor for explaining the growth pattern of neurocranial bones. However, the dynamics of this relation are only partially understood and a detailed characterization of integrated morphological changes of the brain and the neurocranium along ontogeny is still lacking. The aim of this study was to model the effect of brain growth on cranial bones by means of finite-element analysis (FEA) and geometric morphometric techniques.

METHODS

First, we described the postnatal changes in brain size and shape by digitizing coordinates of 3D semilandmarks on cranial endocasts, as a proxy of brain, segmented from CT-scans of an ontogenetic sample. Then, two scenarios of brain growth were simulated: one in which brain volume increases with the same magnitude in all directions, and other that includes the information on the relative expansion of brain regions obtained from morphometric analysis.

RESULTS

Results indicate that in the first model, in which a uniform pressure is applied, the largest displacements were localized in the sutures, especially in the anterior and posterior fontanels, as well as the metopic suture. When information of brain relative growth was introduced into the model, displacements were also concentrated in the lambda region although the values along both sides of the neurocranium (parietal and temporal bones) were larger than under the first scenario.

CONCLUSION

In sum, we propose a realistic approach to the use of FEA based on morphometric data that offered different results to more simplified models.

Minimally Invasive Endoscopic Surgery for Infantile Craniosynostosis: A Longitudinal Cohort Study

OBJECTIVE

To evaluate patient outcomes of minimally invasive endoscopic strip craniectomy (ESC) for craniosynostosis.

STUDY DESIGN

This is a retrospective cohort analysis (2004-2018) of 500 consecutive infants with craniosynostosis treated by ESC with orthotic therapy at a single center. Operative outcomes included transfusions, complications, and reoperations as well as head circumference change based on World Health Organization percentiles. Multivariable logistic regression was used to identify risk factors associated with blood transfusion. Paired t tests were used for within-patient comparisons and Fisher exact test to compare syndromic and nonsyndromic subgroups.

RESULTS

ESC was associated with low rates of blood transfusion (6.6%), complications (1.4%), and reoperations (3.0%). Risk factors for transfusion included syndromic craniosynostosis (P = .01) and multiple fused sutures (P = .02). Median surgical time was 47 minutes, and hospital length of stay 1 day. Transfusion and reoperation rates were higher among syndromic patients (both P < .001). Head circumference normalized by 12 months of age relative to World Health Organization criteria in infants with sagittal, coronal, and multisuture craniosynostosis (all P < .001).

CONCLUSIONS

ESC is a safe, effective, and durable correction of infantile craniosynostosis. ESC can achieve head growth normalization with low risks of blood transfusion, complications, or reoperation. Early identification of craniosynostosis in the newborn period and prompt referral by pediatricians allows families the option of ESC vs larger and riskier open reconstruction procedures.

Head Shape Retention Following Helmet Therapy for Deformational Plagiocephaly

BACKGROUND

The aim of the present study was to evaluate whether any change can be expected in the 6-month period after completing treatment with a molding helmet for deformational plagiocephaly. A retrospective review of helmeted patients from a deformational plagiocephaly clinic from May 2010 to June 2011.

METHODS

A total of 71 individuals with 6-month follow-up after completion of molding helmet treatment were identified. About 51 males and 20 females ranged in age from 2 to 10 months at initial treatment. The main outcome measure was the amount of change in head shape in the 6-month period following molding helmet therapy.

RESULTS

During the course of helmet treatment cephalic index and cranial vault asymmetry both decreased significantly (P < 0.001). Posthelmet follow-ups revealed a further decrease in cephalic index (P < 0.001). Although the cranial vault asymmetry decreased slightly between the final helmeting visit and the follow-up visit, this change was not statistically significant (P = 0.292). Controlling for other factors, continued normalization was not significantly related to helmeting duration.

CONCLUSION

Findings revealed both cephalic index and cranial vault asymmetry improved while in the helmet. During the 6 months following helmet treatment, cephalic index continued to improve; cranial vault asymmetry changed only insignificantly in this same period.

Regression of cephalic index following endoscopic repair of sagittal synostosis

OBJECTIVEMetrics used to quantify preoperative severity and postoperative outcomes for patients with sagittal synostosis include cephalic index (CI), the well-known standard, and the recently described adjusted cephalic index (aCI), which accounts for altered euryon location. This study tracks the time course of these measures following endoscopic repair with orthotic helmet therapy. The authors hypothesize that CI and aCI show significant regression following endoscope-assisted repair.METHODSCT scans or 3D photographs of patients with nonsyndromic sagittal synostosis treated before 6 months of age by endoscope-assisted strip craniectomy and postoperative helmet therapy (n = 41) were reviewed retrospectively at three time points (preoperatively, 0-2 months after helmeting, and > 24 months postoperatively). The CI and aCI were measured at each time point.RESULTSMean CI and aCI increased from 71.8 to 78.2 and 62.7 to 72.4, respectively, during helmet treatment (p < 0.001). At final follow-up, mean CI and aCI had regressed significantly from 78.2 to 76.5 and 72.4 to 69.7, respectively (p < 0.001). The CI regressed in 33 of 41 cases (80%) and aCI in 39 of 41 cases (95%). The authors observed a mean loss of 31% of improvement in aCI achieved through treatment. A strong, positive correlation existed between CI and aCI (R = 0.88).CONCLUSIONSRegression following endoscope-assisted strip craniectomy with postoperative helmet therapy commonly occurs in patients with sagittal synostosis. Future studies are required to determine whether duration of helmet therapy or modifications in helmet design affect regression.

Midfacial growth patterns in males from newborn to 5 years old based on computed tomography

OBJECTIVES

Growth patterns of the human facial skeleton have been of great interest and importance for biological anthropologists, forensic scientists, craniofacial surgeons, and orthopedists. Nevertheless, growth trends of the facial skeleton in infancy and early childhood are still poorly known and clinical CT data have been insufficiently used for studying craniofacial ontogeny. The purpose of this study was to provide a comprehensive quantitative description of human midfacial ontogeny in infancy and early childhood, and to contribute to debates regarding the role of modularity vs. integration in shaping the human face.

METHODS

Our dataset includes 146 high resolution clinical CT datasets of males from the 2nd to 6th years of life and 101 dataset of infants (males) in the 1st year of life. Forty landmarks were collected from each 3D reconstructed skull, then 25 linear measurements describing the morphological features of the facial skeleton were calculated. The integration/modularity issue was addressed via comparison of intragroup correlation matrices at different ages.

RESULTS

Growth trends for all the measurements are presented in charts and tables of statistical parameters that can be used as normative data. The midfacial variables display a great diversity of growth patterns. The correlation structure of the measurements is different at different ages.

CONCLUSIONS

Variables commonly assigned to the same unit of the facial skeleton can exhibit rather different growth trends, but some measurements display seemingly coordinated patterns of growth change. The level of interindividual variation of most measurements is stable after the second half of the first year of life.

Comparing Outcomes and Cost of 3 Surgical Treatments for Sagittal Synostosis: A Retrospective Study Including Procedure-Related Cost Analysis

BACKGROUND

Neurosurgical techniques for repair of sagittal synostosis include total cranial vault (TCV) reconstruction, open sagittal strip (OSS) craniectomy, and endoscopic strip (ES) craniectomy.

OBJECTIVE

To evaluate outcomes and cost associated with these 3 techniques.

METHODS

Via retrospective chart review with waiver of informed consent, the last consecutive 100 patients with sagittal synostosis who underwent each of the 3 surgical correction techniques before June 30, 2013, were identified. Clinical, operative, and process of care variables and their associated specific charges were analyzed along with overall charge.

RESULTS

The study included 300 total patients. ES patients had fewer transfusion requirements (13% vs 83%, P < .001) than TCV patients, fewer days in intensive care (0.3 vs 1.3, P < .001), and a shorter overall hospital stay (1.8 vs 4.2 d, P < .001), and they required fewer revisions (1% vs 6%, P = .05). The mean charge for the endoscopic procedure was $21 203, whereas the mean charge for the TCV reconstruction was $45 078 (P < .001). ES patients had more preoperative computed tomography scans (66% vs 44%, P = .003) than OSS patients, shorter operative times (68 vs 111 min, P < .001), and required fewer revision procedures (1% vs 8%, P < .001). The mean charge for the endoscopic procedure was $21 203 vs $20 535 for the OSS procedure (P = .62).

CONCLUSION

The ES craniectomy for sagittal synostosis appeared to have less morbidity and a potential cost savings compared with the TCV reconstruction. The charges were similar to those incurred with OSS craniectomy, but patients had a shorter length of stay and fewer revisions.

Use of a Midliner Positioning System for Prevention of Dolichocephaly in Preterm Infants

PURPOSE

The purpose of this study was to determine effectiveness of a midliner positioning system (MPS, Tortle Midliner) for preventing dolichocephaly.

METHODS

This was a nonrandomized, prospective study of 30 premature infants (study cohort, SC) using an MPS compared with a retrospective study cohort (RSC) of 65 infants who received standard of care intervention.

RESULTS

RSC baseline cranial index (CI) of 80% and final CI of 77% significantly decreased over an average 5.5 weeks (P < .0001). The SC baseline CI and the final CI were both 79% over an average 5.7 weeks, indicating no significant difference between CI measures (P = .6). Gestational age, birth weight, reflux, time on continuous positive airway pressure, and time in a supine position were not associated with dolichocephaly.

CONCLUSIONS

The SC developed less cranial molding (ie, had greater CI), compared with the RSC. A larger randomized study is needed to recommend routine use of MPS for prevention and/or treatment of cranial molding in premature infants.

A Systematic Approach to Predicting Spring Force for Sagittal Craniosynostosis Surgery

Spring-assisted surgery (SAS) can effectively treat scaphocephaly by reshaping crania with the appropriate spring force. However, it is difficult to accurately estimate spring force without considering biomechanical properties of tissues. This study presents and validates a reliable system to accurately predict the spring force for sagittal craniosynostosis surgery. The authors randomly chose 23 patients who underwent SAS and had been followed for at least 2 years. An elastic model was designed to characterize the biomechanical behavior of calvarial bone tissue for each individual. After simulating the contact force on accurate position of the skull strip with the springs, the finite element method was applied to calculating the stress of each tissue node based on the elastic model. A support vector regression approach was then used to model the relationships between biomechanical properties generated from spring force, bone thickness, and the change of cephalic index after surgery. Therefore, for a new patient, the optimal spring force can be predicted based on the learned model with virtual spring simulation and dynamic programming approach prior to SAS. Leave-one-out cross-validation was implemented to assess the accuracy of our prediction. As a result, the mean prediction accuracy of this model was 93.35%, demonstrating the great potential of this model as a useful adjunct for preoperative planning tool.

Resorbable Construct for Subtotal Cranial Vault Remodeling

INTRODUCTION

Pansynostosis can result in markedly thin calvarial bone resulting in poor quality and quantity of allograft for cranial vault expansion. Such scenarios can result in large calvarial defects and poorly stabilized constructs. Additionally, the osteoinductive properties of neonatal dura and paracranium in cranial vault reconstruction suggest the possibility of reconstructing extensive calvarial defects using minimal native calvarium given the appropriate scaffold. We report a case of subtotal cranial vault remodeling involving greater than 50% of the cranial vault using a custom poly DL lactic acid (Sonic Weld) resorbable plate construct and underlay calvarial bone grafting.

METHODS

A 4-month-old male infant presented with a diagnosis of Cruzon syndrome and pansynostosis. Staged reconstruction was performed with the initial stage involving the posterior and middle cranial vault. Given the severity of the deformity, the native cranial bone was thinned with multiple defects such that it could not be used to provide structural integrity or sufficient surface coverage for cranial vault reconstruction. Useable bone comprised only a fraction of the surface area required to expand the posterior and midcranium. Resorbable poly DL lactic acid (Sonic Weld) plates were used to create a custom construct for reconstruction of the posterior and middle cranial vault. The construct was then seeded with usable fragments of the native calvarium and secured to the cranial base with resorbable pins.

RESULTS

The construct resulted in maintained cranial shape throughout the postoperative period. Postoperative computed tomography imaging demonstrated osteogenesis throughout the construct with bridging of the fragmented calvarial grafts. Examination of the construct during anterior cranial vault remodeling demonstrated near complete resorption of the construct, stable posterior cranial vault, and minimal dural adhesions to the posterior cranium. At 11 months postoperatively, the patient continues to demonstrate appropriate cranial expansion and maintenance of posterior cranial shape.

CONCLUSIONS

Fully resorbable constructs can provide effective structural support and a scaffold for osteogenisis in conjunction with minimal native calvarial bone grafts during reconstruction of large cranial vault defects in the infantile period.

Agreement between cranial and facial classification through clinical observation and anthropometric measurement among Envigado school children

BACKGROUND

To evaluate the agreement between cranial and facial classification obtained by clinical observation and anthropometric measurements among school children from the municipality of Envigado, Colombia.

METHODS

This cross-sectional study was carried out among 8-15-year-old children. Initially, an indirect clinical observation was made to determine the skull pattern (dolichocephalic, mesocephalic or brachycephalic), based on visual equivalence of right eurion- left eurion and glabella-opisthocranion anthropometric points, as well as the facial type (leptoprosopic, mesoprosopic and euryprosopic), according to the left and right zygomatic, nasion and gnation points. Following, a direct measurement was conducted with an anthropometer using the same landmarks for cranial width and length, as well as for facial width and height. Subsequently, both the facial index [euryprosopic (≤80.9%), mesoprosopic (between 81% - 93%) and leptoprosopic (≥93.1%)] and the cranial index [dolichocephalic (index ≤ 75.9%), mesocephalic (between 76% - 81%), and brachycephalic (≥81.1%)] were determined. Concordance between the indices obtained was calculated by direct and indirect measurement using the Kappa statistic.

RESULTS

A total of 313 students were enrolled; 172 (55%) were female and 141 (45%) male. The agreement between the direct and indirect facial index measurements was 0.189 (95% CI 0.117-0261), and the cranial index was 0.388 (95% CI 0.304-0.473), indicating poor concordance.

CONCLUSIONS

No agreement was observed between direct measurements conducted with an anthropometer and indirect measurements via visual evaluation. Therefore, the indirect visual classification method is not appropriate to calculate the cranial and facial indices.