Frontosphenoidal synostosis: a rare cause of unilateral anterior 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.

Fusion of Lateral Calvarial Sutures on Volume-Rendered Computed Tomography Reconstructions in Patients With Known Craniosynostosis

INTRODUCTION

After treating a child with familial sagittal craniosynostosis, clinocephaly, and bilateral parietomastoid/posterior squamosal suture fusion, the authors wondered if major-suture synostosis and clinocephaly were associated with abnormal fusion of minor lateral calvarial sutures.

METHODS

The authors reviewed all preoperative volume-rendered head computed tomography reconstructions performed for craniosynostosis at their institution from 2010 through 2014 and determined whether the sphenoparietal, squamosal, and parietomastoid sutures were open, partially fused, or fused. The authors determined whether any sutures were abnormally fused based upon a previous study from their center, in which abnormal fusion was defined as either 1 of 3 abnormal fusion patterns or abnormally-early fusion. The authors then determined the rate of abnormal fusion of these sutures and whether abnormal fusion was associated with (1) major-suture craniosynostosis, (2) type of craniosynostosis (sutures involved; single-suture versus multisuture; syndromic versus nonsyndromic), and (3) clinocephaly.

RESULTS

In 97 included children, minor lateral sutures were abnormally fused in 8, or 8.2%, which was significantly higher than in children without craniosynostosis from our earlier study. Abnormal minor lateral suture fusion was not associated with the type of single-suture synostosis or with multisuture synostosis but was associated with syndromic synostosis. Four of 8 children with abnormal minor lateral suture fusion had multisuture synostosis and 6 had syndromic synostosis. Lateral sutures were abnormally fused in 1 of 4 subjects with clinocephaly, which was not significant.

CONCLUSION

Abnormal minor lateral calvarial suture fusion is significantly associated with major-suture craniosynostosis, especially syndromic synostosis.

The 27 Facial Sutures: Timing and Clinical Consequences of Closure

SUMMARY

Facial sutures contribute significantly to postnatal facial development, but their potential role in craniofacial disease is understudied. Since interest in their development and physiology peaked in the mid-twentieth century, facial sutures have not garnered nearly the same clinical research interest as calvarial sutures or cranial base endochondral articulations. In addition to reinforcing the complex structure of the facial skeleton, facial sutures absorb mechanical stress and generally remain patent into and beyond adolescence, as they mediate growth and refine the shape of facial bones. However, premature closure of these sites of postnatal osteogenesis leads to disrupted growth vectors and consequent dysmorphologies. Although abnormality in individual sutures results in isolated facial deformities, we posit that generalized abnormality across multiple sutures may be involved in complex craniofacial conditions such as syndromic craniosynostosis. In this work, the authors comprehensively review 27 key facial sutures, including physiologic maturation and closure, contributions to postnatal facial development, and clinical consequences of premature closure.

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.

Isolated Frontosphenoidal Craniosynostosis: The Alder Hey Experience and a Novel Algorithm to Aid Diagnosis

ABSTRACT

Unilateral synostotic frontal plagiocephaly is most commonly due to a premature fusion of the frontoparietal suture. However, the coronal ring comprises of major and minor sutures and these sutures in isolation or in combination can result in similar clinical presentations which can make diagnosis challenging and result in a delay in referral to a craniofacial surgeon for timely management. Isolated frontosphenoidal craniosynostosis is a rare clinical entity with only 49 cases reported in the English literature to date. The authors present our series of 4 patients to add to this cohort of patients and describe key characteristics to distinguish frontoparietal from isolated frontosphenoidal synostosis and introduce a means of differentiating these 2 diagnoses from posterior deformational plagiocephaly and unilateral lambdoid synostosis. All previous case reports have been diagnosed after radiological imaging but the authors have devised a novel algorithm to aid the clinician in diagnosis of craniosynostosis before any radiological imaging.

Isolated Frontosphenoidal Suture Craniosynostosis: Treatment Approaches and Literature Review for a Unique Condition

BACKGROUND

Craniosynostosis isolated to the frontosphenoidal suture is an extremely rare entity, distinct from other types of synostotic anterior plagiocephaly, from the embryologic, phenotypic and endocranial morphology viewpoints. Embryologically, the sphenoid bone has two origins, which morphogenetically represent 2 distinct subunits. Depending on the region involved, unique craniofacial features involving the forehead, temporal region and orbit will be demonstrated. A case of frontosphenoidal suture synostosis depicting these features is presented. In addition, a literature review was performed and a treatment algorithm is proposed.

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.

Temporal Progression of Craniofacial Dysmorphology in Unilateral Coronal Synostosis: A Mechanistic Hypothesis

AIM

This study chronicles skull base and face development in nonsyndromic unilateral coronal synostosis (UCS) during infancy, to characterize the mechanistic progression of facial dysmorphology.

METHODS

Computed tomography scans from 51 subjects were reviewed (26 UCS, 25 controls) and data were reconstructed. Patients were stratified into 5 age groups. A series of measurements were taken from the reconstructions.

RESULTS

All patients had a unilaterally fused coronal suture at the time of analysis. Asymmetry of the sphenoid wings was present across all age groups. The sphenoid wing ipsilateral to the fused suture consistently had a more acute angle from the midline. At 19 days of age, ipsilateral nasal root and cribriform plate deviation are noted, as well as increased contralateral zygoma antero-posterior length. Patients younger than 2 months also had elongated posterior cranial bases. At 2 to 3 months of age, the cranial base widens in the anterior portion of the middle cranial fossa with an increased ipsilateral pterion to sella distance. The most delayed change observed was the increase in contralateral orbital rim angle at 7 to 12 months of age compared to normal.

CONCLUSION

After suture fusion, sphenoid wing changes are among the earliest restructural malformations to take place. This suggests that the cascade of dysmorphology in UCS originates in the cranial vault, then progresses to the skull base, and lastly to the facial structures. Ipsilateral orbital changes are early facial changes in UCS that begin before 2 months of age. This is then followed by changes in the contralateral face later in development.

Progressive Postnatal Pansynostosis

Objective

To describe the subtle clinical features, genetic considerations, and management of progressive postnatal pansynostosis, a rare form of multisutural craniosynostosis that insidiously occurs after birth and causes inconspicuous cranial changes.

Design, Participants, Setting

The study is a retrospective chart review of all patients diagnosed with progressive postnatal pansynostosis at a major craniofacial center between 2000 and 2009. Patients with kleebattschädel were excluded.

Results

Nineteen patients fit our inclusion criteria. Fifteen patients had a syndromic diagnosis: Crouzon syndrome (n = 8), Saethre-Chotzen syndrome (n = 5), and Pfeiffer syndrome (n = 2). With the exception of one patient with moderate turricephaly, all patients had a relatively normal head shape with cranial indices ranging from 0.72 to 0.93 (mean, 0.81). Patients were diagnosed at an average of 32.4 months; craniosynostosis was suspected based on declining percentile head circumference (n = 14), detection of an apical prominence (n = 12), papilledema (n = 7), and worsening exorbitism (n = 3). Nearly all patients had evidence of increased intracranial pressure.

Conclusion

Progressive postnatal pansynostosis is insidious; diagnosis is typically delayed because the clinical signs are subtle and appear gradually. All infants or children with known or suspected craniosynostotic disorder and a normal head shape should be carefully monitored; computed tomography is indicated if there is any decrease in percentile head circumference or symptoms of intracranial pressure.

Isolated Intraorbital Frontosphenoidal Synostosis

Unilateral anterior plagiocephaly is most commonly the result of deformational plagiocephaly or unilateral coronal synostosis, a premature fusion of the frontoparietal suture. However, other sutures within the coronal ring have been implicated in producing anterior cranial asymmetries. These fusions can occur in isolation or in concert with adjacent sutures. The frontosphenoidal suture is one such suture within the coronal ring that has been involved both concomitantly with and independently of frontoparietal suture fusion. Although isolated frontosphenoidal synostosis has been presented previously in the literature, these reports include patients with fusion of the extraorbital portion of the frontosphenoidal suture. This clinical report presents the first clearly documented patient of isolated frontosphenoidal synostosis that occurs entirely within the intraorbital region.The patient presented to Plastic Surgery Clinic at 3 months of age with left frontal flattening, supraorbital rim retrusion, and temporal bulging that was noted soon after birth. Computed tomography analysis revealed an isolated fusion of the greater and lesser wings of the sphenoid bone to the frontal bone on the left side. The patient had no family history of cranial anomalies and genetic testing was negative for mutations. The infant was treated with a cranial orthotic for 3 months, underwent open fronto-orbital advancement and cranial vault remodeling at 6 months, and continued wearing a cranial orthotic for another 4.5 months. Following surgical and orthotic treatment, the patient achieved a satisfactory result.

Defining and Correcting Asymmetry in Isolated Unilateral Frontosphenoidal Synostosis: Differences in Orbital Shape, Facial Scoliosis, and Skullbase Twist Compared to Unilateral Coronal Synostosis

INTRODUCTION

Isolated frontosphenoidal synostosis (FS) is a rare cause of fronto-orbital plagiocephaly that can be challenging to distinguish from isolated unicoronal synostosis (UC). The purpose of this paper is to analyze differences in fronto-orbital dysmorphology between the 2 conditions, to describe approaches for surgical correction, and to report surgical outcomes between FS and UC patients in a casecontrol fashion.

METHODS

Patients treated for craniosynostosis over a 12-year period at our institution were retrospectively evaluated under institutional review board approval. Frontosphenoidal synostosis patients who underwent bilateral fronto-orbital correction of anterior plagiocephaly with minimum 2-year follow-up, adequate pre-, and minimum 2-year postoperative computed tomography scans were included in the case-control portion of the study. These patients were randomly age-matched to UC patients meeting the same inclusion criteria. Preoperative and postoperative orbital shape and volumetric analysis was performed using Mimics software.

RESULTS

Twelve FS patients were treated during the study period. Seven of these patients met casecontrol inclusion criteria with average follow-up of 47.5 months. The characteristic FS orbit was a relatively wide, short, and shallow trapezoid, while the characteristic UC orbit was a relatively narrow, tall, and deep parallelogram. Frontosphenoidal synostosis orbits were significantly wider, shorter, shallower, and smaller than UC orbits. Surgical correction tailored to the differential dysmorphologies resulted in statistical equalization of these differences between affected and contralateral control orbits at follow-up, with the exception of UC orbital width, which remained significantly narrower than unaffected contralateral control. One patient in each group required cranioplasty for skull defects at follow-up, while no patient underwent surgical readvancement.

CONCLUSIONS

Frontosphenoidal synostosis and UC orbital shape differ significantly, and can be normalized using fronto-orbital advancement tailored to the distinct orbital dysmorphologies of these 2 groups.

Craniosynostosis of the Sphenofrontal Suture: Definition of the Main Signs of Craniofacial Deformity

Aims

The aim of this study is to compare clinical features of sphenofrontal craniosynostosis (SFC) and unilateral coronary craniosynostosis.

Settings and Design

This was a retrospective study with two groups of patients with sphenofrontal and coronary craniosynostosis.

Materials and Methods

This was a retrospective study of the 1999-2016 archive data in Russian Children's Clinical Hospital. Ninety-five patients were diagnosed with frontal plagiocephaly. Eighty-three had deformations of unilateral craniosynostosis of coronary suture, 12 had premature closures of sphenofrontal suture. The age at the time of diagnosis varied from 5 months to 2, 5 years.

Results

SFC is featured by ipsilateral flattening of forehead and supraorbital margin, and ipsilateral dystopia of supraorbital margin downward. X-ray signs are the closure of sphenofrontal suture on the lesion side with open and symmetrically located remaining skull sutures and contralateral deviation of the midline of the ethmoid.

Conclusions

SFC distinguishes from other plagiocephalias by following signs: supraorbital margin on the affected side is shifted downward; tip of the nose is displaced toward the affected side, root of the nose toward the healthy side. These signs facilitate correct diagnosis and treatment tactics.

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.

Isolated Unilateral Frontosphenoidal Craniosynostosis: A Rare Cause of Anterior Plagiocephaly

Isolated unilateral frontosphenoidal synostosis is a rare and often misdiagnosed cause of synostotic frontal plagiocephaly. It is important to distinguish the various synostotic causes of frontal plagiocephaly from deformational frontal plagiocephaly because operative intervention is required in synostotic plagiocephaly to avoid progressive deformity, whereas deformational plagiocephaly typically improves without surgery. This study reports a patient with a unique case of anterior plagiocephaly caused by left-sided frontosphenoidal craniosynostosis. The workup should include a thorough history and clinical examination followed by computed tomography scan with three-dimensional reconstruction. Frontosphenoidal synostosis should be suspected in the absence of a coronal synostosis in a child with anterior unilateral plagiocephaly and treated surgically. Good aesthetic and functional results occur with prompt diagnosis and early surgical correction.

Plagiocephaly due to Frontosphenoidal Suture Synostosis: Report of 2 Cases and Literature Review

BACKGROUND/AIMS

The most common cause of anterior plagiocephaly is the fusion of the unilateral coronal suture. In some rare cases, however, the fusion of the frontosphenoidal suture may lead to a resembling pattern with specific clinical and radiological features. The aim of the present study is to further enlighten this entity as it is misdiagnosed most of the time.

METHODS

A report of 2 cases of plagiocephaly due to frontosphenoidal synostosis with a review of the literature.

RESULTS

One female and one male baby were identified. The mean age at presentation was 11.5 months (range: 1-22). Head circumference was normal in each patient. The two fusions were on the left side. Unilateral frontal flattening and recession of the supraorbital rim were the most important physical findings. Computed tomography confirmed the patency of the frontoparietal suture and the closure of the frontosphenoidal suture. Fronto-orbital advancement was performed in both cases with good cosmetic outcome.

CONCLUSION

Frontosphenoidal synostosis should be suspected and carefully searched when dealing with plagiocephaly with patent coronal suture. Good outcome requires a prompt diagnosis and early correction.

Frontosphenoid synostosis: an unusual cause of anterior plagiocephaly

Nonpositional anterior plagiocephaly results commonly from unilateral coronal craniosynostosis. We present 2 patients of a rare cause of anterior plagiocephaly known as frontosphenoid synostosis. This condition is characterized by the absence of a harlequin eye (or the harlequin sign on computed tomography), which is usually present in unilateral coronal synostosis. We also observed no reduction in the ear-eye distance, which can distinguish it from coronal craniosynostosis.

Isolated frontosphenoidal synostosis: a rare cause of synostotic frontal plagiocephaly

OBJECT

Unilateral fusion of the frontoparietal suture is the most common cause of synostotic frontal plagiocephaly. Localized fusion of the frontosphenoidal suture is rare but can lead to a similar, but subtly distinct, phenotype.

METHODS

A retrospective chart review of the authors' craniofacial database was performed. Patients with isolated frontosphenoidal synostosis on CT imaging were included. Demographic data, as well as the clinical and radiographic findings, were recorded.

RESULTS

Three patients were identified. All patients were female and none had an identifiable syndrome. Head circumference was normal in each patient. The mean age at presentation was 4.8 months (range 2.0-9.8 months); 2 fusions were on the right side. Frontal flattening and recession of the supraorbital rim on the fused side were consistent physical findings. No patient had appreciable facial angulation or orbital dystopia, and 2 patients had anterior displacement of the ipsilateral ear. All 3 patients were initially misdiagnosed with unilateral coronal synostosis, and CT imaging at a mean age of 5.4 months (range 2.1-10.8 months) was required to secure the correct diagnosis. Computed tomography findings included patency of the frontoparietal suture, minor to no anterior cranial base angulation, and vertical flattening of the orbit without sphenoid wing elevation on the fused side. One patient underwent CT scanning at 2.1 months of age, which demonstrated a narrow, but patent, frontosphenoidal suture. The patient's condition was assumed to be a deformational process, and she underwent 6 months of unsuccessful helmet therapy. A repeat CT scan obtained at 10.7 months of age demonstrated the synostosis. All 3 patients underwent fronto-orbital correction at mean age of 12.1 months (range 7.8-16.1 months). The mean duration of postoperative follow-up was 11.7 months (range 1.9-23.9 months).

CONCLUSIONS

Isolated frontosphenoidal synostosis should be considered in the differential diagnosis of atypical frontal plagiocephaly.

Identification of skull base sutures and craniofacial anomalies in children with craniosynostosis: utility of multidetector CT

PURPOSE

Craniosynostosis is a condition characterised by the premature fusion of one or more of the cranial sutures. The aim of the study was to identify, by multidetector computed tomography (CT), the involvement of vault sutures as well as of the skull base sutures (named "minor" sutures). The latter ones are involved in development of craniofacial and skull base deformities.

MATERIALS AND METHODS

We retrospectively reviewed 27 children with complex synostosis (n = 21) and anterior synostotic plagiocephaly (n = 6). High-resolution CT images with bone definition algorithm and tridimensional volume rendering reconstructions were assessed.

RESULTS

In 27 children we found different sutures involved in the synostotic process, including both major and minor skull suture synostosis, and synostosis of synchondroses. Superior orbital rim deformity, nasal root deviation, anterior endocranial axis deviation (ethmoidal axis) are found in children with coronal arch synostosis, while reduced size of the posterior fossa and Chiari 1 malformation are noted in children with lambdoid arch synostosis.

CONCLUSIONS

High-resolution CT allows an accurate identification of both "major" and "minor" skull base suture synostosis and it represents the gold standard for the diagnosis of craniostenosis and for planning the proper surgical approach.

Occlusal alterations in unilateral coronal craniosynostosis

There are few studies on maxillomandibular skeletal alterations. Twenty-one patients with unilateral coronal craniosynostosis were analysed and compared with controls. Landmarks analysed were: sella-nasion-point A and B angles, point A-nasion-point B angle, interincisal angle, angle of superior incisor axis on the sella-nasion plane, lower incisor to mandibular plane angle, Frankfort mandibular plane angle, zygomatic-frontal suture (Z), point on the most concave part of pyramidal apophysis of the upper maxilla (Mx), antegonial incisure (AG), upper (UMT) and lower (LMT) molar teeth. Differences were significant for class II dentoskeletal occlusion (p<0.0001), mandibular hyperdivergence (p<0.0001), lingualization of superior incisor (p<0.005), deviation of inferior interincisal contralateral line to the synostosis (p<0.0001) in the plagiocephalic population. Compared with contralateral counterpoints, Z (p<0.05), Mx (p<0.005) and UMT (p<0.0005) on the affected side were closer to the midline; AG (p<0.0005) and LMT (p<0.05) were further from it. On the frontal plane, Z, Mx, UMT, LMT and AG on the affected side were higher. Vertical and transversal contraction of the jaw of the synostotic side and laterodeviation of the mandibular interincisal line of the contralateral synostotic were clear. The altered position of the glenoid cavity, anteriorized in unilateral coronal craniosynostosis, could be the cause of mandibular dentoskeletal asymmetry.

Unilateral frontosphenoidal craniosynostosis with achondroplasia: a case report

Isolated, premature fusion of the frontosphenoidal suture is rare. This report describes an unusual combination of frontosphenoidal craniosynostosis and achondroplasia. Although craniosynostosis is known to occur in allelic conditions such as thanatophoric dysplasia, craniosynostosis in individuals with achondroplasia is exceedingly rare. Due to the distracting diagnosis of achondroplasia or inadequate knowledge of craniosynostosis, the abnormal head shape was initially treated by other physicians with helmet molding. Plastic surgery consultation was obtained at 2 years of age and surgical care was provided. An acceptable head shape was obtained, but the delay in appropriate evaluation was disconcerting. To our knowledge this is the first reported case of isolated frontosphenoidal craniosynostosis associated with achondroplasia.

A biomechanical study on the effect of premature fusion of the frontosphenoidal suture on orbit asymmetry in unilateral coronal synostosis

OBJECTIVE

The coronal ring of patients with unilateral coronal synostosis (UCS) presents premature fusion. This study aims to elucidate whether or not the dynamic behavior of the orbit in response to intracranial pressure (ICP) differs between patients in whom the premature fusion exists only in the frontoparietal suture (FPS) and those in whom the premature fusion extends to the frontosphenoidal suture (FSS).

METHODS

A total of 15 UCS patients were included in the present study. Patients in whom premature fusion was seen inside the FPS and those in whom premature fusion extended to the FSS were categorized as FP Only (4.2 +/- 1.4 m/o) and FP + FS groups (4.6 +/- 2.2 m/o), respectively. On the basis of computed tomography (CT) data, computer-aided design models were produced. Pressure of 15 mm Hg was applied to the neurocranium of each skull model to simulate ICP. Using the finite element method, the displacements presented by each model's orbits were calculated. Displacements of the two groups were compared.

RESULTS

The orbit demonstrated greater displacement in the FP Only group than in the FP + FS group, suggesting that premature closure of the FSS disturbs growth of the orbit in response to ICP.

CONCLUSION

In performing surgical treatment for UCS, the degree of fusion that the FSS presents should be evaluated carefully. In cases in which the FSS presents premature fusion, it is recommended to release the fusion at an early stage of cranial growth to improve the appearance of the orbital region.