Quantitative analysis of craniofacial dysmorphology in infants with anterior synostotic plagiocephaly

Long-term outcomes after surgical correction of anterior plagiocephaly secondary to isolated frontosphenoidal synostosis: a systematic review and two illustrative cases

PURPOSE

Anterior plagiocephaly ( AP), secondary to isolated frontosphenoidal synostosis (IFS), represents one of the rarest forms of craniosynostosis documented in medical literature. Therefore, there is a lack of comprehensive understanding regarding the long-term (> 2 years) postoperative outcomes of this minor suture synostosis.

METHODS

This study presents the long-term outcomes of two patients previously treated for IFS, detailing their clinical, imaging, and postoperative characteristics. Additionally, a systematic review was conducted following PRISMA criteria to summarize existing literature on the topic. The review specifically focuses on long-term aesthetic outcomes, reoperation rates, and complications following surgical intervention for IFS.

RESULTS

Four articles encompassing 12 patients were included in the systematic review. The review highlights clinical features, postoperative complications, reoperation rates, and long-term aesthetic outcomes. The mean age at surgery was 17.5 months (range 9.5-24 months), with an average age at diagnosis of 9.3 months (range 6-10 months). Fronto-orbital advancement was the predominant surgical approach described across all cases. The reoperation rate among patients was 16.6%, with only two cases reporting postoperative complications. In one of our cases, an intraoperative CT scan was utilized to illustrate real-time improvement in frontal bone alignment according to the surgical plan, which significantly contributed to positive long-term clinical outcomes observed during a follow-up period exceeding 24 months.

CONCLUSION

IFS, is a rare minor suture synostosis, significantly affects the aesthetic appearance of the forehead and necessitates consideration in the management of AP cases. Surgical intervention has shown minimal reoperation rates and excellent long-term prognosis. These findings are reinforced by recent institutional data and a comprehensive systematic review of the current literature.

Understanding the heterogenicity of unicoronal synostosis - A morphometric analysis of cases compared to controls

BACKGROUND

Preoperative severity of unicoronal synostosis varies greatly and involves the frontal bone, skull base and orbits. Degree of deformity affects long-term morphological and functional outcomes after surgery. The aim of this study was to describe the morphological heterogenicity and investigate its relation to patient-specific factors.

MATERIALS AND METHODS

In this retrospective cohort study, non-syndromic unicoronal synostosis patients treated between 2006 and 2022 at Necker Hospital, France or Uppsala University Hospital, Sweden, were included and matched to controls. Severity of skull base, orbital and posterior skull asymmetry, degree of anterior plagiocephaly and Harlequin deformity, lateralisation, head circumference, age, timing of metopic fusion and fusion of peri-pterionic sutures were investigated.

RESULTS

Ninety-five patients and ninety-three controls were included. Skull base asymmetry was linearly related to orbital asymmetry (p < 0.001), correlated with earlier CT scans (p = 0.004) and anterior (p < 0.001) and posterior (p = 0.03) plagiocephaly. Posterior plagiocephaly was more common in patients (31%) compared with controls (5%) (p < 0.001). A patent metopic suture above nine months of age was associated with severe Harlequin deformity (p = 0.04) and a lower head circumference when fused (p = 0.03). Fronto-sphenoidal suture fusion was associated with later CT scans (p < 0.001) and less skull base asymmetry (p = 0.002). Spheno-parietal fusion was correlated with decreased skull base asymmetry (p = 0.03). Right lateralisation was more common in females.

CONCLUSIONS

Heterogenicity of unicoronal synostosis seems to be predominantly explained by variability in skull base morphology. Peri-pterionic fusions might limit deformity.

Computed tomography quantitative analysis of cranial vault dysmorphology and severity of facial complex changes in posterior synostotic plagiocephaly patients

BACKGROUND

Posterior synostotic plagiocephaly (PSP) impacts craniofacial skeleton. Study quantifies facial changes in children with PSP to investigate the impact of age and PSP severity at diagnosis on the facial dysmorphology.

MATERIAL AND METHODS

High-resolution preoperative CT images of 22 infants with PSP were analyzed. They were divided according to the early or late age at time of diagnosis. Each group was further subdivided according to the severity of PSP evaluated by the cranial vault asymmetry index (CVAI): mild-moderate PSP (CVAI between 3 and 12%) and severe PSP (CVAI > 12%). Analysis of the facial complex was performed. Each group was compared with age-matched healthy subjects.

RESULTS

All children exhibited unilateral lambdoid suture synostosis. The "early" diagnosis group consisted of 7 children with mild-moderate PSP while the "late" diagnosis group of 15 children in which 6 children had mild-moderate and 9 children severe PSP. All children showed altered position of glenoid fossae and mandibular asymmetry characterized by reduced mandibular diagonal distance length on the affected side while the subgroup of children with severe PSP detected in "late" diagnosis group had also altered mandibular inclination and reduced midfacial depth on both sides.

CONCLUSIONS

PSP causes cranial base dysmorphology which drives changes in facial complex growth; the severity of facial changes mainly depends on the severity of cranial vault dysmorphology detected by CVAI. Mandible reshapes early under the stress of altered biomechanical forces of the skull base while changes in the maxilla are secondary to the asymmetric growth of the mandible and occur only in severe cases.

Craniofacial 3D Morphometric Analysis with Smartphone-Based Photogrammetry

Obtaining 3D craniofacial morphometric data is essential in a variety of medical and educational disciplines. In this study, we explore smartphone-based photogrammetry with photos and video recordings as an effective tool to create accurate and accessible metrics from head 3D models. The research involves the acquisition of craniofacial 3D models on both volunteers and head mannequins using a Samsung Galaxy S22 smartphone. For the photogrammetric processing, Agisoft Metashape v 1.7 and PhotoMeDAS software v 1.7 were used. The Academia 50 white-light scanner was used as reference data (ground truth). A comparison of the obtained 3D meshes was conducted, yielding the following results: 0.22 ± 1.29 mm for photogrammetry with camera photos, 0.47 ± 1.43 mm for videogrammetry with video frames, and 0.39 ± 1.02 mm for PhotoMeDAS. Similarly, anatomical points were measured and linear measurements extracted, yielding the following results: 0.75 mm for photogrammetry, 1 mm for videogrammetry, and 1.25 mm for PhotoMeDAS, despite large differences found in data acquisition and processing time among the four approaches. This study suggests the possibility of integrating photogrammetry either with photos or with video frames and the use of PhotoMeDAS to obtain overall craniofacial 3D models with significant applications in the medical fields of neurosurgery and maxillofacial surgery.

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.

Time course of sutural width during the physiological growth from birth to adulthood: CT quantitative and qualitative evaluations of sutural arches

PURPOSE

We performed a retrospective qualitative and quantitative evaluation of the sutural changes during the physiological growth to define the age-related ossification stages of major and minor skull sutures or synchondroses.

METHODS

A total of 390 healthy subjects, examined for cranio-facial trauma and whose CT scans turned out to be normal, were clustered into homogenous age-matched groups ranged from birth to 90 years. High-resolution CT was used to assess the degree of sutural closure according to a 3-grade scoring system, the sutural pattern, the width, and the density of the gap calculated as the average of two or three ROIs along each suture/synchondrosis.

RESULTS

The identification of a definite pattern depended on the suture's type, the closure degree, and the width of the gap (p < 0.001). The interdigitation process was more intricate for most of vault sutures than the skull base sutures/synchondroses. Closing grades 1, 2, and 3 were associated to an identifiable sutural pattern and the cutoff value of 1.45 mm of the gap width allowed to detect an identifiable sutural pattern with the best combination of sensitivity (97%) and specificity (98%). Age and sutural closing degree were inversely related to gap width while positively related to the gap density (p < 0.001).

CONCLUSION

The sutural ossification is an age-related process, distinctive for each suture, and synchondrosis; it occurs neither according to a predefined order along sutural arches nor following a sequential distribution in the cranial fossae, and some sutures continued their growth process during lifetime.

Facial asymmetry in children with either unilateral lambdoid craniosynostosis or positional posterior plagiocephaly

BACKGROUND

In unilateral lambdoid craniosynostosis (ULC), the posteriorly situated lambdoid suture of the cranial vault fuses prematurely. Positional posterior plagiocephaly (PPP) causes flattening of the posterior side of the head, either through external forces or through underlying differences in brain development. Both conditions cause occipital flattening of the head, but the aetiology is different.

MATERIALS AND METHODS

Eight ULC children were compared with 16 sex- and age-matched PPP children. 3D computer tomography scans of all 24 children were analysed with Dolphin imaging software. The location and symmetry of the temporomandibular joint (Co), and the symmetry of the maxillary anterior nasal spine (ANS) and the mandibular symphysis (Pgn) were analysed. Furthermore, the mandibular bone (Co-Pgn) length, corpus length, ramus height, positional changes in the external acoustic meatus (PoL) and the distance from the orbital margin to the articular fossa were measured.

RESULTS

In all eight ULC children, the Co was anteriorly displaced on the affected side compared with the unaffected side. In all ULC and PPP children, the ANS, which is considered the bony maxillary midpoint, was shifted towards the affected side. In all ULC children, the mandibular bone (Co-Pgn) was shorter on the affected side. The PoL was antero-inferiorly positioned in all ULC children on the affected side compared with the unaffected side.

CONCLUSIONS

Our results show that both types of posterior plagiocephaly are associated with an asymmetric position of the Co and asymmetry of the mandible and maxilla. Facial asymmetry was more frequently seen in ULC than PPP children.

Anterior Synostotic Plagiocephaly: A Quantitative Analysis of Craniofacial Features Using Computed Tomography

The premature fusion of one coronal suture causes anterior synostotic plagiocephaly (ASP), which results in overt craniofacial dysmorphology that could be challenging to correct. This study aimed to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (nonsynostotic) sides in a select cohort of South African patients with ASP, using computed tomography (CT) scans. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on 2-dimensional CT scans of 18 consecutive patients diagnosed with nonsyndromic ASP. The differences between the ipsilateral and contralateral sides were calculated and expressed as a percentage of the contralateral side. All ACF parameters decreased significantly on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (-27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim, height, and surface area parameters increased significantly, with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim, breadth and volume) decreased significantly, with the length-supraorbital rim parameter being the most affected (-10.8%). The ipsilateral ear was found to be displaced anteriorly (9.33 mm) and caudally (5.87 mm) from the contralateral ear. These measures may be useful to surgeons during corrective surgery by indicating the degree of the asymmetry on each side, making it easier to plan the technique and extent of surgical correction of the affected structures.

Physiologic Timeline of Cranial-Base Suture and Synchondrosis Closure

BACKGROUND

Fusion of cranial-base sutures/synchondroses presents a clinical conundrum, given their often unclear "normal" timing of closure. This study investigates the physiologic fusion timelines of cranial-base sutures/synchondroses.

METHODS

Twenty-three age intervals were analyzed in subjects aged 0 to 18 years. For each age interval, 10 head computed tomographic scans of healthy subjects were assessed. Thirteen cranial-base sutures/synchondroses were evaluated for patency. Partial closure in greater than or equal to 50 percent of subjects and complete bilateral closure in less than 50 percent of subjects defined the fusion "midpoint." Factor analysis identified clusters of related fusion patterns.

RESULTS

Two hundred thirty scans met inclusion criteria. The sutures' fusion midpoints and completion ages, respectively, were as follows: frontoethmoidal, 0 to 2 months and 4 years; frontosphenoidal, 6 to 8 months and 12 years; and sphenoparietal, 6 to 8 months and 4 years. Sphenosquamosal, sphenopetrosal, parietosquamosal, and parietomastoid sutures reached the midpoint at 6 to 8 months, 8 years, 9 to 11 months, and 12 years, respectively, but rarely completed fusion. The occipitomastoid suture partially closed in less than or equal to 30 percent of subjects. The synchondroses' fusion midpoints and completion ages, respectively, were as follows: sphenoethmoidal, 3 to 5 months and 5 years; spheno-occipital, 9 years and 17 years; anterior intraoccipital, 4 years and 10 years; and posterior intraoccipital, 18 to 23 months and 4 years. The petro-occipital synchondrosis reached the midpoint at 11 years and completely fused in less than 50 percent of subjects. Order of fusion of the sutures, but not the synchondroses, followed the anterior-to-posterior direction. Factor analysis suggested three separate fusion patterns.

CONCLUSIONS

The fusion timelines of cranial-base sutures/synchondroses may help providers interpret computed tomographic data of patients with head-shape abnormalities. Future work should elucidate the mechanisms and sequelae of cranial-base suture fusion that deviates from normal timelines.

Approach to Fronto-Orbital Sequelae in Anterior Synostotic Plagiocephaly: Our Flow Chart Based on Di Rocco Classification

INTRODUCTION

Anterior synostotic plagiocephaly recognizes the synostosis of one of the hemicoronal sutures as a cause and can manifest itself with varying degrees of severity. Clinically it presents a reduction of the sagittal growth of the affected side and flattening of the frontoparietal complex.

MATERIALS AND METHODS

The authors retrospectively examined our case sample dividing it into 3 groups based on the Di Rocco classification. For each category, we assessed the extent of facial alterations at the end of skeletal growth and retrospectively analyzed the surgical options aimed at correcting aesthetic and skeletal deficits.

RESULTS

The authors found that predictable results could be obtained by standardizing the surgical procedure based on Di Rocco's classification groups; in particular, the authors achieved satisfactory results by assigning a specific surgical procedure to each class.

Cranioorbital Morphology Caused by Coronal Ring Suture Synostosis

BACKGROUND

Minor cranial sutural synostosis is currently regarded as a rare diagnosis. As clinical awareness grows, a greater number of cases are being documented. This study aims to describe the variants of unicoronal synostosis with regard to major and minor sutural involvement and secondary effects on cranial and orbital morphology. The information is aimed to improve clinical diagnosis and management.

METHODS

A retrospective study was conducted collecting preoperative computed tomographic scans of patients diagnosed with unicoronal synostosis and listed for surgical interventions, identified from a craniofacial database. Within these patients, different synostotic variants were identified based on which suture was affected. Scans of normal pediatric skulls (trauma) were used for a control group. Computed tomographic scans were analyzed for sutural involvement, cranial base deflection, and ipsilateral and contralateral orbital height and width. One-way analysis of variance was used to detect differences between synostotic variants and controls.

RESULTS

A total of 57 preoperative computed tomographic scans of patients with unicoronal synostosis were reviewed, in addition to 18 computed tomographic scans of normal skulls (control group). Four variants of unicoronal synostosis were identified: frontoparietal, frontosphenoidal, frontoparietal and frontosphenoidal, and frontosphenoidal and frontoparietal. The last two variants differ in their temporal involvement in the direction of sutural synostosis and ultimately cranial and orbital morphology. Three variants have been previously identified, but the fourth is presented for the first time.

CONCLUSIONS

An understanding of the variants of unicoronal synostosis and their temporal relationships is integral for accurate clinical diagnosis and surgical correction. Recommendations for treatment are based on discrete changes in orbital morphology.

Dipyridamole-loaded 3D-printed bioceramic scaffolds stimulate pediatric bone regeneration in vivo without disruption of craniofacial growth through facial maturity

This study investigates a comprehensive model of bone regeneration capacity of dypiridamole-loaded 3D-printed bioceramic (DIPY-3DPBC) scaffolds composed of 100% beta-tricalcium phosphate (β -TCP) in an immature rabbit model through the time of facial maturity. The efficacy of this construct was compared to autologous bone graft, the clinical standard of care in pediatric craniofacial reconstruction, with attention paid to volume of regenerated bone by 3D reconstruction, histologic and mechanical properties of regenerated bone, and long-term safety regarding potential craniofacial growth restriction. Additionally, long-term degradation of scaffold constructs was evaluated. At 24 weeks in vivo, DIPY-3DPBC scaffolds demonstrated volumetrically significant osteogenic regeneration of calvarial and alveolar defects comparable to autogenous bone graft with favorable biodegradation of the bioactive ceramic component in vivo. Characterization of regenerated bone reveals osteogenesis of organized, vascularized bone with histologic and mechanical characteristics comparable to native bone. Radiographic and histologic analyses were consistent with patent craniofacial sutures. Lastly, through application of 3D morphometric facial surface analysis, our results support that DIPY-3DPBC scaffolds do not cause premature closure of sutures and preserve normal craniofacial growth. Based on this novel evaluation model, this DIPY-3DPBC scaffold strategy is a promising candidate as a safe, efficacious pediatric bone tissue engineering strategy.

Quantitative analysis of cranial-orbital changes in infants with anterior synostotic plagiocephaly

PURPOSE

The effects of premature fusion of one coronal suture cause skull and orbital alterations in term of side-to-side asymmetry. This study aimed to quantify the cranio-orbital complex changes related to the severity of skull base dysmorphology in patients with unicoronal synostosis.

METHODS

Twenty-four infants affected by unicoronal synostosis were subdivided in three subgroups according to the severity of skull base deformity and their high-resolution CT images were quantitatively analyzed (groups IIa, IIb, III). Dimensions of cranial fossae, intracranial volume (ICV), ICV synostotic and ICV non synostotic side, whole brain volume (WBV), orbital volumes (OV), ICV/WBV, ICV_synostotic/ICV_{non-synostotic}, and OV_synostotic/OV_{non-synostotic} were evaluated.

RESULTS

Asymmetry and reduction in the growth of the anterior and middle fossae were found in all groups while asymmetry of the posterior cranial fossa was found only in IIb and III groups. In all groups, ICV, WBV, and ICV/WBV were not significantly different while ICV_synostotic/ICV_{non-synostotic} and OV_synostotic/OV_{non-synostotic} resulted significant difference (p < 0.05). ICV_{synostotic side} resulted reduction only in group III. OV on the synostotic side was not significantly reduced although a trend in progressively reducing volumes was noted according to the severity of the group.

CONCLUSION

Skull and orbital changes revealed a side-to-side asymmetry but the effects of the premature synostosis were more severe in group III suggesting an earlier timing of premature unicoronal synostosis in group III with respect to the other groups. The assessment of the skull base deformity might be an indirect parameter of severity of skull orbital changes and it might be useful for surgical planning.

A New Operative One-Wing Technique to Correct Fronto-Orbital Region in Unilateral Nonsyndromic Plagiocephaly

Anterior plagiocephaly is a premature closing of unilateral coronal suture. This premature suture fusion causes a series of cranial asymmetry and alteration of the fronto-orbital region.The authors described a new surgical technique to correct the facial asymmetry that reduces the operative time and the possible complications.In a period between 2013and 2016, 12 children affected by nonsyndromic anterior plagiocephaly were treated with this new procedure.Clinical, cranial development, and absence of postoperative complication demonstrated that one-wing surgical bone correction is a useful and innovative technique.