Evaluation of Direct Surgical Remodeling of Frontal Bossing in Patients With Sagittal Synostosis

3D Analysis of the Cranial and Facial Shape in Craniosynostosis Patients: A Systematic Review

With increasing interest in 3D photogrammetry, diverse methods have been developed for craniofacial shape analysis in craniosynostosis patients. This review provides an overview of these methods and offers recommendations for future studies. A systematic literature search was used to identify publications on 3D photogrammetry analyses in craniosynostosis patients until August 2023. Inclusion criteria were original research reporting on 3D photogrammetry analyses in patients with craniosynostosis and written in English. Sixty-three publications that had reproducible methods for measuring cranial, forehead, or facial shape were included in the systematic review. Cranial shape changes were commonly assessed using heat maps and curvature analyses. Publications assessing the forehead utilized volumetric measurements, angles, ratios, and mirroring techniques. Mirroring techniques were frequently used to determine facial asymmetry. Although 3D photogrammetry shows promise, methods vary widely between standardized and less conventional measurements. A standardized protocol for the selection and documentation of landmarks, planes, and measurements across the cranium, forehead, and face is essential for consistent clinical and research applications.

Biparietal remodelling and total vault remodelling in scaphocephaly-a comparative study using 3d stereophotogrammetry

PURPOSE

The aim of the study was to compare the results of two surgical techniques for the treatment of isolated sagittal synostosis (ISS) by means of 3D stereophotogrammetry. One technique, the Renier's "H" technique (RHT) comprised a biparietal expansion, the other, the total vault remodeling (TVR) included also a frontal remodeling.

METHODS

The two groups of operated children were compared with a third control group of normocephalic children. The 3D scanning was performed in all children between 12 and 245 months of age. On each 3D image six measurements and indices have been made, with the aim of evaluating not only length and width of the head, but also the height. The cranial index (CI) was measured in a plane parallel to the nasion-tragus plane, at the intersection with the opisthocranion.

RESULTS

Each of the three groups (RHT, TVR, control group) included 28 children. The measurements that were influenced by the correction of the frontal bossing, namely the CI and the sagittal length, were closer to normocephaly after TVR than after RHT. Lesser or no statistical difference was documented in the measurements evaluating the biparietal aspect and the height of the vertex, indicating that the biparietal expansion is effective in both procedures.

CONCLUSION

Based on our results TVR results in a better esthetical outcome, particularly in relation to the direct surgical remodeling of the frontal bossing.

Technique for Cephalometric Analysis of the Craniofacial Skeleton Following Facial Feminization Surgery

Facial feminization surgery (FFS) is characterized by a series of relatively diverse procedures aimed at aligning skeletal and soft tissue facial appearance with one's experienced feminine gender. Although there are several well-described outcomes from surgical techniques, there is no standardized methodology to provide reliable analyses of postoperative FFS outcomes. This paper describes the first reliable and reproducible technique to accurately and consistently measure post-FFS changes to guide surgical planning to optimize patient outcomes.

A New Measure of Posterior Morphology in Sagittal Craniosynostosis: The Occipital Bullet Index

INTRODUCTION

Sagittal craniosynostosis (SC) is associated with scaphocephaly, an elongated narrow head shape. Assessment of regional severity in the scaphocephalic head is limited by the use of serial computed tomographic (CT) imaging or complex computer programing. Three-dimensional measurements of cranial surface morphology provide a radiation-free alternative for assessing cranial shape. This study describes the creation of an occipital bulleting index (OBI), a novel tool using surface morphology to assess the regional severity in patients with SC.

METHODS

Surface imaging from CT scans or 3D photographs of 360 individuals with SC and 221 normocephalic individuals were compared to identify differences in morphology. Cartesian grids were created on each individual's surface mesh using equidistant axial and sagittal planes. Area under the curve (AUC) analyses were performed to identify trends in regional morphology and create measures capturing population differences.

RESULTS

The largest differences were located in the medial regions posteriorly. Using these population trends, a measure was created to maximize AUC. The OBI has an AUC of 0.72 with a sensitivity of 74% and a specificity of 61%. When the frontal bossing index is applied in tandem, the two have a sensitivity of 94.7% and a specificity of 93.1%. Correlation between the two scores in individuals with SC was found to be negligible with an intraclass correlation coefficient of 0.018. Severity was found to be independent of age under 24 months, sex, and imaging modality.

CONCLUSIONS

This index creates a tool for differentiating control head shapes from those with SC and has the potential to allow for objective evaluation of the regional severity, outcomes of different surgical techniques, and tracking shape changes in individuals over time, without the need for radiation.

Three-Dimensional Assessment of Frontal Bossing and Temporal Pinching in Patients with Sagittal Craniosynostosis Using Curvature Analysis

BACKGROUND

Sagittal craniosynostosis results in varying degrees of frontal bossing and bilateral temporal pinching. This study assessed the three-dimensional changes in these regions using curvature analysis and volumetric analysis before and 1 year after extended sagittal strip craniectomy (ESC) with postoperative helmet therapy.

METHODS

A retrospective review of three-dimensional photographs of 50 subjects treated with ESC with postoperative helmet therapy and 50 age-matched controls was performed. Images were collected preoperatively and 1 year postoperatively. Forehead convexity and temple concavity were quantified. Computed tomographic scans of subjects with and without sagittal synostosis were analyzed to assess the percentage of total intracranial volume (ICV) in the anterior cranial fossa before and after ESC with postoperative helmet therapy.

RESULTS

Forehead convexity in the ESC with postoperative helmet therapy group preoperatively (24.49 ± 3.16 m -1 ) was significantly greater than controls (22.48 ± 3.84 m -1 ; P = 0.005). Forehead convexity significantly decreased after ESC with postoperative helmet therapy (18.79 ± 2.43 m -1 ; P < 0.001) and did not differ from controls (19.67 ± 3.08 m -1 ; P = 0.115). The ESC group had more concave temples preoperatively (-10.27 ± 4.37 m -1 ) as compared with controls (-6.99 ± 3.55 m -1 ; P < 0.001). Temple concavity significantly decreased after ESC (-4.82 ± 3.17 m -1 ; P < 0.001) and did not differ from controls (-5.64 ± 3.27 m -1 ; P = 0.075). In the ESC group, the percentage ICV in the anterior cranial fossa decreased from 22.03% to 18.99% after surgery, whereas the anterior volume in controls was stable (17.74% to 16.81%).

CONCLUSIONS

The ESC group had significantly greater forehead convexity, temple concavity and anterior cranial fossa volume compared with controls. One year after ESC with postoperative helmet therapy, forehead convexity, temple concavity, and percentage ICV in the anterior fossa were comparable to controls.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Management of Sagittal and Lambdoid Craniosynostosis: Open Cranial Vault Expansion and Remodeling

The prevalence of sagittal and lambdoid suture craniosynostosis differs considerably, as they are notably the most and least prevalent sutures involved in isolated suture craniosynostosis, respectively. The goals of reconstructing the cranial vault in both entities is the same: to release the fused suture, expand cranial volume, restore normal head shape and morphology, and allow for normal growth of the cranial vault. With regards to sagittal suture synostosis, opinions vary on whether reconstruction should focus on either the anterior or poster cranial vault. In contrast, the poster cranial vault is always targeted in lambdoid suture craniosynostosis.

Morphologic Differences in Sagittal Synostosis with Age before Surgery

BACKGROUND

It is important to determine whether sagittal synostosis-associated scaphocephaly is static in the presurgical period, or whether there are morphologic differences with time to include in surgical decision-making. The authors' purpose was to perform cross-sectional analysis of cranial morphology before any surgical intervention in children with sagittal synostosis younger than 9 months compared to matched controls.

METHODS

The authors performed morphometric analysis on computed tomographic scans from 111 untreated isolated sagittal synostosis patients younger than 9 months and 37 age-matched normal controls. The authors divided the patients into three age groups and performed statistical comparison between sagittal synostosis and controls for each group.

RESULTS

Sagittal synostosis cephalic indices were stable and lower in patients than in controls across groups. Total cranial volume was equivalent, but sagittal synostosis patients had a greater posterior volume than controls at all ages and a smaller middle fossa volume at older ages. Pterional width was greater in sagittal synostosis patients than in controls for each age group. Frontal bossing vectors were most severe in the youngest age groups and least in the older group. Occipital protuberance was consistent across the age groups.

CONCLUSIONS

Upper parietal narrowing and occipital protuberance were the consistent deformities across age groups, with the most parietal constriction seen in older patients. Frontal bossing was not consistent and was more severe in the younger patients. The authors did not detect significant pterional constriction, and the appearance of constriction is relative to adjacent morphology and not absolute.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.