Mandibular alterations and facial lower third asymmetries in unicoronal synostosis

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.

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.

Management of Unicoronal and Metopic Synostoses: Minimally Invasive Approaches

Early endoscopic-assisted correction of unicoronal and metopic synostosis is an excellent, safe, cost-effective, and highly effective option for affected patients. Although open calvarial remodeling has a place in the armamentarium of the craniofacial team, the skull base changes seen in endoscopic-assisted techniques are unparalleled. The procedures are associated with low morbidity and no mortality. There is minimal blood loss, decreased operating time, significantly reduced blood transfusion rates, decreased hospitalization length, decreased cost, and less pain and swelling. Early diagnosis and referral for surgical evaluation are critical to obtaining these results.

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.

Spatially Detailed 3D Quantification of Improved Facial Symmetry After Surgery in Children With Unicoronal Synostosis

OBJECTIVE

To assess improvement of soft-tissue facial symmetry in children surgically treated for unicoronal synostosis (UCS) in infancy, to correlate pre- and postsurgical facial asymmetry and to evaluate whether the improvement was visually recognizable.

DESIGN

Case-controlled follow-up.

PATIENTS/SETTINGS

Eleven Danish children diagnosed with UCS were included, 3 of whom had tested positive for Muenke mutation. Preoperative computed tomography scans and postoperative 3dMD surfaces were available for measurements. A control group of healthy children matched for age and sex was employed.

MAIN OUTCOME MEASURES

Pre- and postsurgical facial asymmetry was analyzed using a computerized method capable of objective and spatially detailed quantification in 3-dimension (transverse, vertical, and sagittal directions). Asymmetry was evaluated in the facial region and 6 subregions (forehead, mouth, eyes, nose, cheek, and chin).

RESULTS

The largest significant improvement was seen in the sagittal direction of the facial (1.9 mm), forehead (2.0 mm), and cheek (3.4 mm) regions. Small but significant improvements were also seen in the mouth, chin, and eye regions. No significant improvement was seen in the nose region. Significant correlations were found between the pre- and postsurgically calculated facial asymmetry and between calculated asymmetry and clinical validation scores.

CONCLUSIONS

All patients presented with improved facial symmetry after surgery and the improvements were visually recognizable. However, only 1 (9.1%) of the 11 patients reached a level of facial asymmetry as low as that seen in the control group. The best outcome was, in general, seen in cases with mild facial asymmetry presurgically.

Postsurgical Changes in Osseous Dysmorphology of the Midface and Mandible in Unilateral Coronal Craniosynostosis

BACKGROUND

Early management of unilateral coronal synostosis (UCS) aims to treat the cranial abnormality with the hope of improving middle and lower facial morphology. This study analyzed osseous volume and 3-dimensional distances in the midface and mandible of patients with UCS to assess changes in facial symmetry following a cranial vault procedure.

METHODS

Patients who underwent fronto-orbital advancement for UCS repair between 1981 and 2012 with follow-up of at least 3 years were included. Computed tomography-based 3-dimensional reconstructions of the mandible and LeFort III midface were divided by 3 midline osseous landmarks and measured for volume. Distances between 11 osseous landmarks were measured in the midface and mandible. Ratios between the measurements on synostotic and nonsynostotic sides were calculated. Presurgical to postsurgical changes were evaluated with paired samples t tests. The study was powered to detect differences between preoperative and postoperative ratios of at least 3%.

RESULTS

Eleven patients were included. Mean age at initial imaging was 4.7 ± 3.2 months (range, 0.4-9.2 months) with postoperative follow-up of 9.0 ± 5.3 years (range, 3.3-17.0 years). Midfacial symmetry of osseous volume improved following surgery (synostotic to nonsynostotic ratio, 94.1% vs 98.9%, P = 0.044). The width (P < 0.001), height (P = 0.039), and anterior-posterior depth of the midface (P = 0.011) also became more symmetric. In the mandible, however, volumetric and linear symmetry did not improve.

CONCLUSIONS

Symmetry of the midface, but not the mandible, improves significantly following the cranial procedure in patients with UCS.

How does nonsyndromic craniosynostosis affect on bone width of nasal cavity in children? - Computed tomography study

Craniosynostosis is caused by premature fusion of one or more cranial sutures, restricting skull, brain and face growth. Nonsyndromic craniosynostosis could disturb the proportions of face. Although morphometric diameters of nasal cavity in healthy children are already known, they have not been established yet in children with nonsyndromic craniosynostosis. The aim our study was to check whether diameters of bone structures of nasal cavity in children with nonsyndromic craniosynostosis measured in CT are within normal range. 249 children aged 0–36 months (96 with clinical diagnosis of nonsyndromic craniosynostosis and 153 in control group) were included into the study. The following diameters were measured on head CT scans: anterior bony width (ABW), bony choanal aperture width (BCAW), right and left posterior bony width (between bone sidewall and nasal cavity septum—RPBW and LPBW). The study group has been divided into 4 categories, depending on child’s age. The dimensions measured between bone structures of nasal cavity were statistically significantly lower in comparison to the control group. They did not depend on the sex for ABW, nor on age in groups 7–12 months and < 2 years for BCAW, RPBW and LPBW. The measured dimensions increased with age. In children with nonsyndromic craniosynostosis the diameter of pyriform aperture and bony choanal aperture were lower than in controls, what may be described as fronto-orbital anomalies. Morphometric measurements of anthropometric indicators on CT scans could be used as standards in the clinical identification of craniosynostosis type and may help in planning surgical procedures, particularly in the facial skeleton in children.

Quantitative analysis of craniofacial dysmorphology in infants with anterior synostotic plagiocephaly

PURPOSE

The study aimed to identify premature synostosis of "major" and "minor" sutures of the coronal sutural arch and splanchnocranium sutures to evaluate the relationship between craniofacial dysmorphology and the sutural pattern in children with anterior plagiocephaly.

METHODS

A quantitative analysis of the skull base and facial changes was performed on preoperative high-resolution CT images in 18 children with anterior synostotic plagiocephaly and compared with imaging findings in 18 age-matched healthy subjects.

RESULTS

All patients had patent splanchnocranium sutures. Fifteen out of 18 children showed early and isolated synostosis of the unicoronal suture (the major suture of the coronal ring) and were classified in groups II and III according to the classification scheme of anterior synostotic plagiocephaly based on the severity of craniofacial dysmorphology. Premature fusion of the unilateral coronal suture in groups II and III caused a marked asymmetry and reduced growth of the anterior and middle fossae on the synostotic side and a secondary varying severity in terms of asymmetric growth of the facial complex. Although both groups showed anterior displacement of the mandibular articulation on the synostotic side, group II showed only maxillary asymmetry, while group III showed maxillary and mandibular asymmetry.

CONCLUSIONS

In anterior synostotic plagiocephaly, the severity of skull base changes and asymmetric growth of the facial complex is not caused by skull base sutural synostotic involvement but is probably related to the different timing of unilateral coronal suture closure.

Facial changes after early treatment of unilateral coronal synostosis question the necessity of primary nasal osteotomy

BACKGROUND

The premature fusion of unilateral coronal suture can cause a significant asymmetry of the craniofacial skeleton, with an oblique deviation of the cranial base that negatively impacts soft tissue facial symmetry. The purpose of this study was to assess facial symmetry obtained in patients with unilateral coronal synostosis (UCS) surgically treated by 2 different techniques. We hypothesized that nasal deviation should not be addressed in a primary surgical correction of UCS.

METHODS

Consecutive UCS patients were enrolled in a prospective study and randomly divided into 2 groups. In group 1, the patients underwent total frontal reconstruction and transferring of onlay bone grafts to the recessive superior orbital rim (n = 7), and in group 2, the patients underwent total frontal reconstruction and unilateral fronto-orbital advancement (n = 5). Computerized photogrammetric analysis measured vertical and horizontal axis of the nose and the orbital globe in the preoperative and postoperative periods. Intragroup and intergroup comparisons were performed.

RESULTS

Intragroup preoperative and postoperative comparisons showed a significant (all P < 0.05) reduction of the nasal axis and the orbital-globe axis in the postoperative period in the 2 groups. Intergroup comparisons showed no significant difference (all P > 0.05).

CONCLUSIONS

Facial symmetry was achieved in the patients with UCS who underwent surgery regardless of surgical approach evaluated here. Our data showed a significant improvement in nasal and orbital-globe deviation, leading us to question the necessity of primary nasal correction in these patients.