Percentile-based assessment of craniosynostosis

The utility and post-operative evolution of head circumference in nonsyndromic single-suture craniosynostosis: a prospective study in Vietnamese children

PURPOSE

Head circumference (HC) is an important clinical tool for following head growth in children with craniosynostosis (CS). The purpose of this study is to quantify the usefulness of HC along continuum of CS care, from diagnosis to pre- and post-operative (pre-op, post-op) follow-up in Vietnamese children.

METHODS

A prospective cohort of 54 nonsyndromic single-suture CS patients undergoing open surgery from January 2015 to January 2020 was collected at Children's Hospital 2, Vietnam. HC z-score on admission was compared with World Health Organization (WHO) standards to evaluate for utility in initial diagnosis. Pre-op and post-op HC were compared to demonstrate the evolution of head growth following reconstruction.

RESULTS

Nonsyndromic single-suture CS was more predominant in males (79.6%) than in females (20.4%). The mean HC z-score was - 0.38 [Formula: see text] 1.29 similar to normal WHO standards regardless of which sutural involvement. The HC z-score increased above + 1 standard deviation (SD) significantly at 3 months of follow-up (p < 0.001); however, the trajectory gradually decreased after the first year of surgery. One patient (1.8%, 1/54) demonstrated restenosis and delayed intracranial hypertension (DIH) 4 years after reconstruction.

CONCLUSIONS

The HC in nonsyndromic single-suture CS children presents similarly to the values of healthy children. Additionally, HC reliably increased after reconstruction and gradually normalized over subsequent years. This indicator is consistent in Southeast Asian populations and should be used to follow all patients to assess the normal progression of post-op head growth and as a useful indicator of suspected recurrent synostosis.

High risk factors for craniosynostosis during pregnancy: A case-control study

Background

Craniosynostosis is a birth defect involving premature cranial sutures’ fusion with an increasing prevalence and unknown underlying causes in nearly 80% of cases. The current study investigates a series of high-risk factors associated with a non-syndromic craniosynostosis.

Methods

Ninety-seven (97) children were included in the retrospective case-control study, 62 controls and 35 with craniosynostosis. A questionnaire with 143 questions was used in face-to-face interviews. After univariate analyses, stepwise multivariate logistic regression analysis was implemented.

Results

In craniosynostosis group, 3 out of 4 were male subjects and 2 out of 3 born with caesarian section. History for central nervous system abnormalities in their younger siblings, low birth weight, extended use of mobile phone from the parents and medications’ use differed significantly between craniosynostosis and control group. After adjustment for all factors, only maternal medication use (aOR 6,1 [2.1 – 19], CI 95%) and oral progesterone intake (aOR 4 [1.2 – 14], CI 95%) were significantly associated with an increased risk in craniosynostosis group.

Conclusion

The maternal medications’ use and particular oral progesterone intake is associated with an increased risk for non-syndromic craniosynostosis. However, due to the study’s limitations, further research is warranted.

Anthropometric cranial measurements in metopic craniosynostosis/trigonocephaly: diagnostic criteria, classification of severity and indications for surgery

ABSTRACT

Metopic craniosynostosis is the second most frequent type of craniosynostosis. When the phenotypic presentation has been deemed severe the treatment is surgical in nature and is performed in infancy with fronto-orbital advancement and cranial vault remodeling. At the time of this writing, there is no consensus regarding an objective evaluation system for severity, diagnostic criteria, or indications for surgery. This study aims to review the anthropometric cranial measurements and the relative diagnostic criteria/classification of severity/surgical indications proposed so far for this skull malformation, and to investigate if there is any scientific support for their utility.

Visualization of skull remodeling and re-ossification after reconstructive surgery and mosaic-like cranioplasty in sagittal synostosis and deformational brachycephaly1

INTRODUCTION

Extended vertex craniectomy in sagittal synostosis (SS) and transposition craniectomy in severe deformational brachycephaly (DB) combined with mosaic-like cranioplasty (M-LC) have been performed in 17 and 24 infants from 2001 to 2003. The hitherto not well-known mechanisms of remodeling and effectiveness of M-LC is assessed by X-ray and anthropometry.

METHODS

Follow-ups included skull radiograms preoperatively and 3 and 15 months postoperatively, which were analyzed by craniometry according to Haas, long-term anthropometry, and clinical follow-up till mean age of 7.6 and 7.4 years. Analysis included the following: time course of cephalic indexes (CI), sizes of distances (breadth, length, height) and modulus, and mean deviation of distances and modulus from the normal age- and sex-dependent values; evaluation of re-ossification of the operative defects covered by M-L C.

RESULTS

CI in SS is normalized in early follow-up with stabilization thereafter; CI of DB is gradually normalized till late follow-up. Remodeling occurs in both disorders by active and passive mechanisms: increased growth of distances with preoperative minus and decreased growth of distances with surplus. The latter mechanism adds more to the postoperative remodeling. M-LC leads to concentric and final complete re-ossification of the defects.

DISCUSSION

Significant remodeling of the skull vault is observed in both disorders by the demonstrated time course and mechanisms. M-LC does not hinder early remodeling and guarantees re-ossification of the defects.

Dimensional, Geometrical, and Physical Constraints in Skull Growth

After birth, the skull grows and remodels in close synchrony with the brain to allow for an increase in intracranial volume. Increase in skull area is provided primarily by bone accretion at the sutures. Additional remodeling, to allow for a change in curvatures, occurs by resorption on the inner surface of the bone plates and accretion on their outer surfaces. When a suture fuses too early, normal skull growth is disrupted, leading to a deformed final skull shape. The leading theory assumes that the main stimulus for skull growth is provided by mechanical stresses. Based on these ideas, we first discuss the dimensional, geometrical, and kinematic synchrony between brain, skull, and suture growth. Second, we present two mechanical models for skull growth that account for growth at the sutures and explain the various observed dysmorphologies. These models demonstrate the particular role of physical and geometrical constraints taking place in skull growth.

The metopic index: an anthropometric index for the quantitative assessment of trigonocephaly from metopic synostosis

OBJECTIVE Because the metopic suture normally fuses during infancy, there are varying degrees of severity in head shape abnormalities associated with premature fusion. A method for the objective and reproducible assessment of metopic synostosis is needed to guide management, as current methods are limited by their reliance on aesthetic markers. The object of this study was to describe the metopic index (MI), a simple anthropometric cranial measurement. The measurements can be obtained from CT scans and, more importantly, from palpable cranial landmarks, and the index provides a rapid tool for evaluating patients in both pre- and postoperative settings. METHODS High-resolution head CT scans obtained in 69 patients (age range 0-24 months) diagnosed with metopic craniosynostosis were retrospectively reviewed. Preoperative 3D reconstructions were available in 15 cases, and these were compared with 3D reconstructions of 324 CT scans obtained in a control group of 316 infants (age range 0-24 months) who did not have any condition that might affect head size or shape and also in a subset of this group, comprising 112 patients precisely matched to the craniosynostosis patients with respect to age and sex. Postoperative scans were available and reviewed in 9 of the craniosynostosis patients at a mean time of 7.1 months after surgical repair. 3D reconstructions of these scans were matched with controls based upon age and sex. RESULTS The mean preoperative MI for patients with trigonocephaly was 0.48 (SD 0.05), significantly lower than the mean values of 0.57 (SD 0.04) calculated on the basis of all 324 scans obtained in controls (p < 0.001) and 0.58 (SD 0.04) for the subset of 112 age- and sex-matched controls (p < 0.001). For 7 patients with both pre- and postoperative CT scans available for evaluation, the mean postoperative MI was 0.55 (SD 0.03), significantly greater than their preoperative MIs (mean 0.48 [SD 0.04], p = 0.001) and comparable to the mean MI of the controls (p = 0.30). In 4 patients, clinically obtained postoperative MIs by caliper measurement were comparable to measurements derived from CT (p = 0.141). CONCLUSIONS The MI is a useful measurement of the severity of trigonocephaly in patients with metopic synostosis. This simple quantitative assessment can potentially be used in the clinical setting to guide preoperative evaluation, surgical repair, and postoperative degree of correction.

Expansion and compression distraction osteogenesis based on volumetric and neurodevelopmental analysis in sagittal craniosynostosis

PURPOSE

Distraction osteogenesis (DO) is a less daunting procedure than extensive cranial vault remodeling and has been used to correct sagittal craniosynostosis. The purposes of this study are to describe DO in combination with expansion and compression procedures and to report analytic results based on the cranial index (CI), volumetric measurement, and neurodevelopmental tests.

METHODS

Between June 2002 and May 2013, 32 patients with non-syndromic sagittal synostosis who had undergone antero-posterior compression with bitemporal expansion were recruited. Circumferential baseline, mid-sagittal, and bicoronal craniotomies were performed in addition to four-quadrant bone flap procedures via distraction with dural attachment. CI, intracranial volume (ICV), head circumference (HC), and neurodevelopmental outcomes using the Bayley Scales of Infant Development-II (BSID-II) scoring system were analyzed.

RESULTS

Dolichocephalic CI (68.85 ± 3.61) was altered to mesocephalic CI (78.28 ± 3.74) postoperatively. Preoperative ICV and HC determinations were within the normal range for the majority of participants (normal ICV 87.5%, n = 28; normal HC 75%, n = 24). ICV and HC did not show significant changes with postoperative measurements and were maintained within normal ranges. Regarding neurodevelopment, both the mental and psychomotor developmental indices (MDI, PDI) demonstrated significant improvement (MDI, 88.69 ± 17.38 to 96.23 ± 21.05; PDI, 91.38 ± 16.31 to 100 ± 11.51; p < 0.05).

CONCLUSIONS

Symmetric sagittal synostosis can be treated comprehensively through DO in combination with expansion and compression procedures. ICV and HC measurements were useful for designing surgical and postoperative distraction strategies. Achievement of mesocephalic CI and neurodevelopmental improvement validated morphological and functional effectiveness.

Anthropometry of craniosynostosis

BACKGROUND

Anthropometry is becoming a popular method for diagnostics of various diseases in pediatric clinical practice. The aim of this study was to assess the growth changes in craniofacial parameters in patients with craniosynostosis and positional plagiocephaly.

METHODS

Inclusion criteria for the study were presence of craniostenosis or positional plagiocephaly in a patient with at least three anthropometric evaluations at our department. Studied patients were aged from 1.0 month to 2.5 years with median age at the first and last anthropometric evaluation as 1.83 and 25.27 months, respectively. Further anthropometric results in patients older than 2.5 years were excluded from the study. Statistical significance was tested by the Mann-Whitney test.

RESULTS

The studied group consisted of 70.5% male patients. The type of craniosynostosis was represented by scaphocephaly in 44.1%, by trigonocephaly in 45.6% and by coronal craniosynostosis in 10.3% of the cases. Cranial index was proven as a suitable parameter for evaluating differences in the trend of growth in craniosynostosis (p<0.001) and also for evaluating post-operative results. Significance was found in width of the head (p=0.038) for scaphocephaly and in length of the head for trigonocephaly (p=0.001) in surgically treated patients. Trend of cranial growth in operated patients copied the curve of the norm but in higher or lower values which depends on the type of prematurely closed suture.

CONCLUSION

Longitudinal anthropometric follow-up is an objective and measurable method that can accurately non-invasively and non-expensively assess skull growth in pediatric patients with cranial deformity.

A study of cranial variations based on craniometric indices in a South Indian population

BACKGROUND

Human skull has been the most extensively studied bone for establishing the taxonomies at evolutionary levels. Crania are also the most commonly used skeletal elements in population studies because they are known to be more genetically driven and less affected by environmental factors. The craniofacial indices are considered as clinical anthropometric parameters used in the investigation of craniofacial skeletal deformities and brain development. The present research is an attempt to study the cranial indices in the South Indian population.

METHODS

The sample for the study included 118 dry adult crania. All the osteometric measurements were taken using standard anthropometric instruments, and 3 indices, namely, cranial index, orbital index (OI), and index of foreman magnum (FMI), were calculated. Cranial index is calculated as (maximum cranial breadth / maximum cranial length) × 100, OI as (orbital height / orbital breadth) × 100, and FMI as (transverse diameter / anteroposterior diameter) × 100. The crania were further classified based on these indices.

RESULTS

The cranial index ranged between 66.67 and 85.71 (mean, 78.57 [SD, 4.11]), the OI ranged between 68.89 and 102.63 (mean, 84.23 [SD, 6.64]), and the FMI ranged between 68.57 and 96.88 (mean, 79.71 [SD, 6.98]). Cranial index did not show any significant correlation with the OI (r = -0.162, P = 0.081) or the FMI (r = -0.045, P = 0.626). A statistically significant correlation was, however, observed between OI and FMI (r = -0.232, P = 0.012).

CONCLUSIONS

The current study developed population-specific classification of crania using cranial indices. This craniometric baseline data pertaining to the craniofacial indices may be useful in presurgical planning and the postsurgical evaluation. It may also assist the forensic anthropologists in the categorization of human skulls, which may be an important component in identification of highly decomposed dead bodies and skeletal remains. More such studies need to be conducted to understand the effect of environment and genetics on the cranial shapes in different population groups.