New diagnostic approach of the different types of isolated craniosynostosis

Creation of the Scaphocephalic Index: Measurement of Global and Regional Severity in Scaphocephaly

BACKGROUND

The recently described frontal bossing index (FBI) and occipital bullet index (OBI) allow for quantification of scaphocephaly. A similar index examining biparietal narrowing has not been described. Addition of such an index measuring width would allow for direct evaluation of the primary growth restriction in sagittal craniosynostosis and the formation of an optimized global width/length measure.

METHODS

Computed tomography scans and three-dimensional photographs were used to recreate scalp surface anatomy. Equidistant axial, sagittal, and coronal planes were overlaid, creating a Cartesian grid. Points of intersection were analyzed for population trends in biparietal width. Using the most descriptive point coupled with the sellion protrusion to control for head size, the vertex narrowing index is formed. By combining this index with the FBI and OBI, the scaphocephalic index (SCI) is created as a tailored width/length measure.

RESULTS

Using 221 controls and 360 individuals with sagittal craniosynostosis, the greatest difference occurred superiorly and posteriorly at a point 70% of the head's height and 60% of the head's length. This point had an area under the curve of 0.97 and sensitivity and specificity of 91.2% and 92.2%, respectively. The SCI has an area under the curve of 0.9997, sensitivity and specificity greater than 99%, and interrater reliability of 0.995. The correlation coefficient between computed tomography imaging and three-dimensional photography was 0.96.

CONCLUSIONS

The vertex narrowing index, FBI, and OBI evaluate regional severity, while the SCI is able to describe global morphology in patients with sagittal craniosynostosis. These measures allow for superior diagnosis, surgical planning, and outcome assessment, independent of radiation.

UCSQ Method Applied on 3D Photogrammetry: Non-Invasive Objective Differentiation Between Synostotic and Positional Plagiocephaly

OBJECTIVE

Objective differentiation between unilateral coronal synostosis (UCS) and positional posterior plagiocephaly (PPP) based on 3D photogrammetry according to Utrecht Cranial Shape Quantificator (UCSQ).

DESIGN

Retrospective study.

SETTING

Primary craniofacial center.

PATIENTS, PARTICIPANTS

Thirty-two unoperated patients (17 UCS; 15 PPP) (age < 1 year).

INTERVENTIONS

Extraction of variables from sinusoid curves derived using UCSQ: asymmetry ratio forehead and occiput peak, ratio of gradient forehead and occiput peak, location forehead and occiput peak.

MAIN OUTCOME MEASURE(S)

Variables, derived using 3D photogrammetry, were analyzed for differentiation between UCS and PPP.

RESULTS

Frontal peak was shifted to the right side of the head in left-sided UCS (mean x-value 207 [192-220]), and right-sided PPP (mean x-value 210 [200-216]), and to the left in right-sided UCS (mean x-value 161 [156-166]), and left-sided PPP (mean x-value 150 [144-154]). Occipital peak was significantly shifted to the right side of the head in left-sided PPP (mean x-value 338 [336-340]) and to the left in right-sided PPP (mean x-value 23 [14-32]). Mean x-value of occipital peak was 9 (354-30) in left- and 2 (350-12) in right-sided UCS. Calculated ratio of gradient of the frontal peak is, in combination with the calculated asymmetry ratio of the frontal peak, a distinctive finding.

CONCLUSIONS

UCSQ objectively captures shape of synostotic and positional plagiocephaly using 3D photogrammetry, we therefore developed a suitable method to objectively differentiate UCS from PPP using radiation-free methods.

Classification of Skull Shape Deformities Related to Craniosynostosis on 3D Photogrammetry

Implementation of the Utrecht Cranial Shape Quantificator (UCSQ) classification method on 3D photogrammetry in patients with different types of craniosynostosis is the aim of the present study. Five children (age <1 year) of every group of the common craniosynostoses (scaphocephaly, brachycephaly, trigonocephaly, right-sided and left-sided anterior plagiocephaly) were randomly included. The program 3-Matic (v13.0) was used to import and analyze the included 3dMD photos. Three external landmarks were placed. Using the landmarks, a base plane was created, as well as a plane 4 cm superior to the base plane. Using UCSQ, we created sinusoid curves of the patients, the resulting curves were analyzed and values were extracted for calculations. Results per patient were run through a diagnostic flowchart in order to determine correctness of the flowchart when using 3D photogrammetry. Each of the patients (n=25) of the different craniosynostosis subgroups is diagnosed correctly based on the different steps in the flowchart. This study proposes and implements a diagnostic approach of craniosynostosis based on 3D photogrammetry. By using a diagnostic flowchart based on specific characteristics for every type of craniosynostosis related to specific skull deformities, diagnosis can be established. All variables are expressed in number and are therefore objective.

Validation of Skully Care as a Fast Method for Quantifying Positional Cranial Deformities

Objective

Craniofacial measuring is valuable for diagnosis and evaluation of growth and treatment of positional skull deformities. Plagiocephalometry (PCM) quantifies skull deformities and is proven to be reliable and valid. However, PCM needs direct skin contact with thermoplastic material, is laborious and time-consuming. Therefore, Skully Care (SC) was developed to measure positional skull deformities with a smartphone application.

Design

SC is retrospectively compared to PCM.

Setting

Pediatric physiotherapy centers.

Patients

Age ≤1 year, analyzed or treated for positional skull deformities.

Interventions

A total of 60 skull shape analyses were performed.

Main Outcome Measures

The main outcome measures employed are Pearson correlation coefficient between cranial vault asymmetry index (CVAI; in SC) and oblique diameter difference index (ODDI; in PCM) and between cranial index (CI; in SC) and cranial proportional index (CPI; in PCM). Mann–Whitney U test determined difference of time consumption between PCM and SC.

Results

High correlation was found between CVAI and ODDI (r = 0.849; P < .01) in positional plagiocephaly and very high correlation between CI and CPI (r = 0.938; P < .01) in positional brachycephaly. SC is significantly faster than PCM (P < .001).

Conclusions

SC is valid in analyzing positional skull deformities and strongly correlates to PCM, the gold standard in daily physiotherapy practice. The combination of simplicity, validity, speed, and user and child convenience makes SC a promising craniofacial measuring method in daily practice. SC has potential to be the modern successor for analyzing positional skull deformities.

Orbital volume, ophthalmic sequelae and severity in unilateral coronal synostosis

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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