Apert Patients Research Articles

Resection of Fourth-to-Fifth Metacarpal Synostosis and Fascial Interposition for Creation of a Functional Grip/Pinch in the Apert Hand.

Fourth-to-fifth metacarpal synostosis, present in a majority of Apert hands, flattens the metacarpal arch, restricts metacarpal descent, may prevent opposition of border rays, and negates any functional flexion. Restoration of position and mobility with arthroplasty changes the plane of flexion and enables both pinch and grip. This report summarizes the evolution of the authors' technique over 5 decades. In a cohort of 184 Apert patients (368 hands), the presence, anatomy, and level of metacarpal synostosis with a classification was determined. The present technique consists of incision along the ulnar border of the hand, wide excision of the skeletal coalition, release of dorsal structures, and soft-tissue interposition. Data consisted of clinical records, serial molds, radiographs, and occupational therapy records. Follow-up ranged from 3 to 44 years. A total of 147 patients (80% of hands) had bilateral fourth-to-fifth metacarpal synostoses, the extent of which correlated with the Apert hand classification. In 72 patients, the synostosis was resected and cadaveric fascia interposed. Synostosis refusion occurred in 38 hands, all of which were treated early in the series and in patients younger than 6 years old. Despite refusion, the position of the fifth digit had improved, and the flat transverse arch was in a more curved or cupped posture. The distance between the opposing border rays was always improved, and a new grip and pinch mechanism created. Aggressive ostectomy of synostosis and fascial interposition places the ulnar side of the hand in a much more functional position. In conjunction with thumb lengthening, opposition between the thumb and fifth finger becomes a clinical reality in children with Apert syndrome. Therapeutic, IV.

Apert syndrome: neurosurgical outcomes and complications following posterior vault distraction osteogenesis.

Posterior vault distraction osteogenesis (PVDO) has been utilized during the past 15 years to treat a variety of clinical features commonly presented by patients with Apert syndrome. The objective of this study is to determine the efficacy of PVDO in addressing both elevated intracranial pressure (ICP) and ectopia of the cerebellar tonsils (ECT) in young Apert patients. In addition, we aimed to determine the prevalence of hydrocephalus in Apert syndrome patients who underwent PVDO. A retrospective study was made with a cohort of 40 consecutive patients with syndromic craniosynostosis (SC), previously diagnosed with Apert syndrome, who underwent PVDO between 2012 and 2022, and thereafter received at least 1 year of follow-up care. Demographic data and diagnosis, along with surgical and outcome data, were verified using medical records, clinical photographs, radiologic examination, and interviews with the parents of all cohort patients. The average patient age when PVDO was performed was 12.91 ± 10 months. The average posterior advancement distance achieved per patient was 22.68 ± 5.26mm. The average hospital stay per patient was 3.56 ± 2.44 days. The average absolute and relative blood transfusion volumes were 98.47ml and 17.63ml/kg, respectively. Although five patients (14%) presented ECT preoperatively, this condition was completely resolved by PVDO in three of these five patients. One of the three patients whose ECT had completely resolved presented syringomyelia postoperatively, requiring subsequent extra dural foramen magnum decompression. All of the remaining four patients were asymptomatic for ECT for at least 1 year of follow-up, and none of these four patients required any additional treatments to address ECT. Two patients presented hydrocephalus requiring ventriculoperitoneal shunt placement. This study demonstrates that PVDO both reduces diagnosed elevated ICP symptoms and is partially effective in treating ECT in Apert syndrome patients. Hydrocephalus in Apert syndrome is an uncommon feature. The effectiveness of PVDO in addressing hydrocephalus is uncertain.

Orbital and Eyelid Characteristics, Strabismus, and Intracranial Pressure Control in Apert Children Treated by Endoscopic Strip Craniectomy versus Fronto-Orbital Advancement.

Twenty-five patients treated at Boston Children's Hospital met inclusion criteria for this retrospective cohort study. Primary outcomes were magnitude of palpebral fissure downslanting at 1, 3, and 5 years of age, severity of V-pattern strabismus, rectus muscle excyclorotation, and interventions to control ICP. Before craniofacial repair and through 1 year of age, none of the studied parameters differed for FOA versus ESC treated patients. Palpebral fissure downslanting became statistically greater for those treated by FOA by 3 (P < 0.001) and 5 years of age (P = 0.001). Likewise, severity of palpebral fissure downslanting correlated with severity of V-pattern strabismus at 3 (P = 0.004) and 5 (P = 0.002) years of age. Palpebral fissure downslanting and rectus muscle excyclorotation were typically coexistent (P = 0.053). Secondary interventions to control ICP were required in four of 14 patients treated by ESC (primarily FOA) and in two of 11 patients initially treated by FOA (primarily third ventriculostomy) (P = 0.661). Apert patients initially treated by ESC had less severe palpebral fissure downslanting and V-pattern strabismus, normalizing their appearance. Thirty percent initially treated by ESC required secondary FOA to control ICP.

Apert Syndrome: Selection Rationale for Midface Advancement Technique.

Apert syndrome is characterized by a wide spectrum of craniofacial clinical features that have been successfully addressed via a variety of midface advancement techniques. Although surgeons have individual preferences as to which specific procedures should be performed to best treat Apert patients, craniofacial plastic surgeons, working in tandem with pediatric neurosurgeons, can identify and evaluate functional limitations and facial morphologic disproportions, and establish appropriate criteria for effective midface advancement technique indication and selection. The purpose of this review article is to present and discuss our rationale for midface advancement technique selection based upon the most common craniofacial characteristics presented by Apert syndrome patients. The present article also provides a grading system that stratifies as major, moderate, and mild, the effect of each midface advancement technique on the different types of Apert syndrome facial features. Surgeons should take into consideration the maximum effect and benefit of each craniofacial osteotomy and how these procedures will alter the craniofacial skeleton. By understanding the long-term effect of each osteotomy on the most common craniofacial characteristics of Apert syndrome patients, craniofacial plastic surgeons and neurosurgeons will be able to customize the surgical procedures they perform in order to achieve the best possible outcomes.

Two-Center Review of Posterior Vault Expansion following a Staged or Expectant Treatment of Crouzon and Apert Craniosynostosis.

The timing of posterior cranial expansion for the management of intracranial pressure can be "staged" by age and dysmorphology or "expectant" by pressure monitoring. The authors report shared outcome measures from one center performing posterior vault remodeling (PCVR) or distraction (PVDO) following a staged approach and another performing spring-assisted expansion (SAPVE) following an expectant protocol. Apert or Crouzon syndrome patients who underwent posterior expansion younger than 2 years were included. Perioperative outcomes and subsequent cranial operations were recorded up to last follow-up and intracranial volume changes measured and adjusted using growth curves. Thirty-eight patients were included. Following the expectant protocol, Apert patients underwent SAPVE at a younger age (8 months) than Crouzon patients (16 months). The initial surgery time was shorter but total operative time, including device removal, was longer for PVDO (3 hours 52 minutes) and SAPVE (4 hours 34 minutes) than for PCVR (3 hours 24 minutes). Growth-adjusted volume increase was significant and comparable. Fourteen percent of PCVR, 33% of PVDO, and 11% of SAPVE cases had complications, but without long-term deficits. Following the staged approach, 5% underwent only PVDO, 85% had a staged posterior followed by anterior surgery, and 10% required a third expansion. Following the expectant approach, 42% of patients had only posterior expansion at last follow-up, 32% had a secondary cranial surgery, and 26% had a third cranial expansion. Two approaches involving posterior vault expansion in young syndromic patients using three techniques resulted in comparable early volume expansion and complication profiles. Therapeutic, III.

Apert Syndrome Type III Hand: Prevalence and Outcomes.

The Upton type III hand, which represents the most severe hand type among Apert syndrome patients, has been considered the least prevalent hand type. The objective of this study is to address type III Apert hand prevalence and describe treatment strategies that will result in a 5 digit hand. The authors retrospectively reviewed 15 years of Apert syndrome hand practice at our hospital. Demographic (patient sex and age at the time of the operation), surgical (eg, techniques used for webspace release, osteotomy, and various aspects of soft-tissue reconstruction), and outcome (perioperative and long-term complication and need for revision operation) data was verified through medical records, clinical photographs, radiographic images, and interviews with patients' families. Patients who had incomplete medical records and/or postoperative follow up <6 months in length were excluded from this study. A total of 93 Apert patients [50 male (56.1%) and 43 female (43.9%)] were treated at our hospital from 2007 to 2021. Stratification of Apert hand severity using Upton's classification system identified 34 patients with type I hands (36.4%), 19 patients with type II hands (20.6%), and 40 patients with type III hands (43%). Of the 40 patients with type III hands a 5 digit hand was achieved for 35 patients (87%), with an average of 3.37 operations per patient. The Upton type III hand is the most prevalent hand type among Apert syndrome patients. Following a three stage protocol, a surgical team can consistently achieve a 5 digit hand for the majority of Apert syndrome patients with type III hands.

Orbital and eyelid characteristics and strabismus severity in children with apert syndrome treated by early endoscopic strip craniectomy versus fronto-orbital advancement

Apert syndrome is characterized by craniofacial and orbital abnormalities and associated with V-pattern strabismus. We compare orbital and eyelid characteristics and strabismus severity in Apert patients treated by endoscopic strip craniectomy (ESC) versus fronto-orbital advancement (FOA).

Posterior vault distraction osteogenesis in Apert syndrome

Apert syndrome is an uncommon autosomal dominant condition with a varied clinical spectrum which includes premature cranial and facial suture fusion and complex upper and lower limb syndactilies. In this manuscript, we share our posterior vault distraction osteogenesis (PVDO) experience regarding Apert syndrome patients so that a larger patient population may benefit. In addition, we aimed to determine an onset of elevated intracranial pressure in the long term follow up.&#x0D; A retrospective study was performed on consecutive patients with syndromic craniosynostosis who were diagnosed with Apert syndrome, underwent PVDO between 2012 and 2019, and received at least 2 years of follow-up care. Demographic data, diagnosis, surgery related data, and outcome data (perioperative and mid-term complications and need for additional surgery), were verified by means of medical records, clinical photographs, radiographic images, and interviews with all included patients and/or their parents.&#x0D; The present study included 14 patients who were diagnosed respectively with Apert syndrome (n = 14). The average posterior advancement distance achieved was 19.37 ± 3.0 mm. Two patients included in this study presented major complications, but neither experienced permanent sequelae or a lethal course. Two Apert patients presented cerebral spinal fluid (CSF) leakage (Clavien–Dindo type II). One patient presented a onset of elevated intracranial pressure at 4 years of follow up.&#x0D; PVDO is an effective procedure at alleviating intracranial pressure and present a low complication rate.&#x0D; &#x0D; &#x0D;

Hypertelorbitism Corrected by Facial Bipartition Improves Exotropia.

The purpose of this study was to detail perioperative ophthalmologic evaluations to characterize functional ocular outcomes after facial bipartition surgery. Patients with hypertelorbitism who underwent facial bipartition surgery were studied specifically for eye motility disorders by separating patients into rare craniofacial clefts (midline and paramedian) (n = 34) and craniofacial dysostosis (Apert, Crouzon, and Pfeiffer) (n = 74). Preoperative and postoperative (12 months) ophthalmologic examinations (with depth perception tests), computed tomography scans, and magnetic resonance imaging scans were analyzed. Among craniofacial cleft patients, mean interdacryon distance was reduced from 39 ± 4 mm to 17 ± 2 mm, with strabismus improved from 88 percent (exotropia 82 percent) preoperatively to only 29 percent postoperatively. Depth perception improved to a lesser degree, with abnormal tests at a rate of 79 percent preoperatively to 56 percent postoperatively. Wider hypertelorbitism had a higher degree of strabismus. Among craniofacial dysostotic patients, mean interdacryon distance was reduced from 37 ± 3 mm to 17 ± 2 mm, and strabismus improved from 55 percent to only 14 percent. Depth perception improved to a lesser degree, with 68 percent abnormal tests preoperatively and 46 percent postoperatively. Apert patients had more V-pattern strabismus and exotropia (79 percent) than did other craniofacial dysostosis patients (42 percent). The authors' data indicate that facial bipartition for hypertelorbitism-known to improve periorbital aesthetics-also improves eye motility disturbances. Thus, vision problems related to exotropia should be considered a functional indication for facial bipartition surgery in patients with hypertelorbitism. Therapeutic, IV.

Influence of Nonsyndromic Bicoronal Synostosis and Syndromic Influences on Orbit and Periorbital Malformation.

Oculoorbital disproportion in patients with craniosynostosis has similarities and dissimilarities between syndromic and nonsyndromic cases. The authors hypothesized that these two conditions have specific individual influences as they relate to development of the orbital and periorbital skeletons. A total of 133 preoperative computed tomography scans (nonsyndromic bicoronal synostosis, n = 38; Apert syndrome bicoronal synostosis subtype, n = 33; Crouzon syndrome bicoronal synostosis subtype, n = 10; controls, n = 52) were included. Craniometric and volumetric analyses related to the orbit and periorbital anatomy were performed. Orbital cavity volume was mildly restricted in nonsyndromic bicoronal synostosis (7 percent, p = 0.147), but more so in Apert and Crouzon syndromes [17 percent (p = 0.002) and 21 percent (p = 0.005), respectively]. The sphenoid side angle in Apert syndrome was wider than when compared to Crouzon syndrome (p = 0.043). The ethmoid side angle in Apert patients, however, was narrower (p = 0.066) than that in Crouzon patients. Maxilla anteroposterior length was more restricted in Apert syndrome than Crouzon syndrome (21 percent, p = 0.003) and nonsyndromic cases (26 percent, p < 0.001). The posterior nasal spine position was retruded in Crouzon syndrome (39 percent, p < 0.001), yet the anterior nasal spine position was similar in Apert and Crouzon syndromes. Orbit and periorbital malformation in syndromic craniosynostosis is likely the combined influence of syndromic influences and premature suture fusion. Apert syndrome expanded the anteriorly contoured lateral orbital wall associated with bicoronal synostosis, whereas Crouzon syndrome had more infraorbital rim retrusion, resulting in more severe exorbitism. Apert syndrome developed maxillary hypoplasia, in addition to the maxillary retrusion, observed in Crouzon syndrome and nonsyndromic bicoronal synostosis patients. Risk, II.

QS3: Influence Of Nonsyndromic Bicoronal Synostosis And Syndromic Influences On And Periorbital Malformation

BackgroundOculo-orbital disproportion in patients with craniosynostosis have similarities and dissimilarities between syndromic and nonsyndromic cases. We hypothesize these two conditions have specific individual influences as it relates to development of the orbital and periorbital skeletons.MethodA total of 133 preoperative CT scans (nonsyndromic bicoronal synostosis, n=38; Apert syndrome bicoronal synostosis subtype, n=33; Crouzon syndrome bicoronal synostosis subtype, n=10; controls, n=52) were included. Craniometric and volumetric analyses related to the orbit and periorbital anatomy were performed.ResultsThe orbital cavity volume is mildly restricted in nonsyndromic bicoronal synostosis (7%, p=0.147), but more so in Apert and Crouzon syndromes, 17% (p=0.002) and 21% (p=0.005), respectively. The sphenoid side angle in Apert syndrome is wider than when compared to Crouzon syndrome (p=0.043). The ethmoid side angle in Apert patients however is narrower (p=0.066) than that in Crouzon patients. Maxilla anteroposterior length is more restricted in Apert syndrome than Crouzon syndrome (21%, p=0.003) and nonsyndromic cases (26%, p<0.001). The posterior nasal spine position is retruded in Crouzon syndrome (39%, p<0.001), yet the anterior nasal spine position is similar in Apert and Crouzon syndromes.ConclusionOrbit and periorbital malformation in syndromic craniosynostosis is likely the combined influence of syndromic influences and premature suture fusion. Apert syndrome expands the anteriorly contoured lateral orbital wall associated with bicoronal synostosis, while Crouzon syndrome has more infraorbital rim retrusion, resulting in more severe exorbitism. Apert syndrome develops maxillary hypoplasia, in addition to the maxillary retrusion, observed in Crouzon syndrome and nonsyndromic bicoronal synostosis patients.

Apert Syndrome Outcomes: Comparison of Posterior Vault Distraction Osteogenesis Versus Fronto Orbital Advancement.

Presenting a wide clinical spectrum and large variety of clinical features, successful treatment of Apert syndrome necessitates performance of sequential multiple surgeries before a patient's facial skeleton growth is complete.The objective of this study is to compare forehead contour asymmetry and clinical outcomes between Apert patients who underwent either fronto-orbital advancement (FOA) or posterior vault distraction osteogenesis (PVDO). A retrospective study was performed on consecutive patients with Apert syndrome who underwent either FOA or PVDO between 2007 and 2019, and participated in at least 6 months of follow-up care. Forehead contour asymmetry and surgical outcomes for each of the included patients were verified through medical records, clinical photographs, and interviews with the parents of the patients. The need for additional craniofacial procedures based on the surgical outcomes of each patient was graded from I to IV utilizing the Whitaker outcome classification system. Forehead contour asymmetry for all included patients was rated under the Whitaker grading scale as type II (n = 4) 44.4%, type III (n = 2) 22.2%, and type IV (n = 3) 33.3% for FOA, and type I (n = 5) 35.7%, type II (n = 7) 50%, and type III (n = 2) 14.3%, for PVDO (P < 0.05). The average transfused blood volume was 47.77 ± 9.42 mL/kg for patients who underwent FOA, and 22.75 ± 10.31 mL/kg for patients who underwent PVDO (P < 0.05). Patients who underwent PVDO had lower forehead contour asymmetry as per the Whitaker outcome grading scale than patients who underwent FOA.

Intracranial Volume Measured and Correlated to Cephalic Index in Syndromic and Nonsyndromic Anterior Brachycephaly.

Premature fusion of both coronal sutures (anterior brachycephaly) alters skull shape and potentially affects intracranial volume (ICV). Currently little is known about preoperative ICV in anterior brachycephaly. Aim is to measure preoperative ICV and compare this with normative data. Additionally, ICV will be correlated to most used clinical method of quantification: cephalic index (CI). Preoperative patients with anterior brachycephaly (age, ≤12 months) were included and categorized by syndrome (when present). Computed tomography scans were used for ICV measurement by manual segmentation (OsiriX (Fondation OsiriX, Geneva, Switzerland)). Intracranial volume of each subgroup was compared with Lichtenberg normative cranial volume growth curves for controls. Cephalic index was calculated and correlated to ICV using Pearson correlation coefficient. Thirty-four patients with both syndromic and nonsyndromic anterior brachycephaly were included: 17 with Apert syndrome, 6 with Muenke syndrome, 5 with Saethre Chotzen syndrome, 3 with Crouzon, 1 with craniofrontonasal dysplasia, and 2 nonsyndromal. Mean age at preoperative computed tomography scan was 4 months (1-10 months). Mean ICV was 847.31 cm3 (473.91-1459.22 cm3). Nineteen of 34 patients had skull volumes between ±2 SD curves of Lichtenberg, none of the patients had an ICV smaller than -2 SD and 15 of 34 had an ICV larger than +2 SD. Mean ICV in Apert syndrome was 829.85 cm3 (473.91-1061.53 cm3), in Muenke syndrome 942.06 cm3 (768.02-1136.75 cm3), in Saethre Chotzen syndrome 779.72 cm3 (609.21-1002.95 cm3), in Crouzon syndrome 700.57 cm3 (652.31-784.32 cm3), in craniofrontonasal dysplasia 738.97 cm3, and in the nonsyndromal group 1154.64 cm3 (850.07-1459.22 cm3). Apert had a mean greater than +2SD above the mean, the other subgroups had a mean within normal ranges (±2 SD). Correlation between severity of brachycephaly and overall ICV was low (r = 0.42). Mean preoperative ICV in both syndromic and nonsyndromic anterior brachycephaly was 847.31 cm3. Intracranial volume in anterior brachycephaly is in 55.9% between normal ranges (±2 SD). In 44.1% ICV was greater than +2 SD, especially in Apert syndrome (11/16 Apert patients). None of the included patients had a deviant small ICV of less than -2 SD. Additionally, low correlation between ICV and CI (r = 0.42) was found and therefore CI is not suitable for estimating ICV in anterior brachycephaly.

Apert Hand Reconstruction: Do Partial-Thickness Skin Grafts Result in Flexion Scar Contracture?

Hand reconstruction for patients with Apert syndrome is a critical step in comprehensive care and enables this population to gain significant hand function. Digit separation for Apert syndrome, as described in most algorithms, is finalized using local flaps and full-thickness skin grafts. The objective of this study is to report our experience using local flaps and partial-thickness skin grafts after digit separation for Apert hand reconstruction. An observational retrospective study was performed with Apert patients whose hands were reconstructed between January 2007 and July 2019 using local flaps and partial-thickness skin grafts after digit separation. Demographic data and outcome data were verified and recorded. Out of a total of 75 Apert patients who underwent hand reconstruction, 12 underwent hand reconstruction utilizing local flaps and partial-thickness skin grafts. The average patient age at the time of the first procedure was 1.9 years. These 12 patients were stratified according to Upton hand severity, 3 being type I (25%), 3 being type II (25%) and 6 being type III (50%). Mean follow up provided to all patients in this study was 1.8 years and donor site-related complications were seen in 2 patients (16.6%). No flexion scar contracture was observed in any of the patients who received partial-thickness skin grafts. The use of local flaps along with partial-thickness skin grafts to finalize digit separation for patients with Apert syndrome is an effective technique that reduces donor site morbidity and does not result in flexion scar contracture.

Airway Development Relevant to Cranial Vault Suture Synostosis Subtype in Apert Syndrome

Introduction: Based on an established classification system of Apert syndrome subtypes, we aim to directly analyze the correlation between segmented airway volume changes and different skull suture synostosis, so as to provide individualized surgical planning for each subgroup of Apert patients. Methods: CT scans of 44 unoperated Apert syndrome and 53 controls were included and subgrouped as: type I. Bilateral coronal synostosis; type II. Pansynostosis; type III. Perpendicular combinations of cranial vault synostosis. CT scans were measured using Mimics and 3-matics software. Results: Type I developed a 41% ( P = .116) reduction in the nasal cavity, yet a normal sized pharyngeal airway. The reduced nasal airway was linked to the decreased cross sectional area ( r = 0.598, P = .001), vertical dimension ( r = 0.719, P &lt; .001), and narrower width ( r = 0.727, P &lt; .001). Type II developed proportionally reduced nasal airway and pharyngeal airway volumes (both 47%, P = .113 and P = .041), along with the proportionally restricted cross sectional areas at choana and condylion levels by 62 to 65%. This reduction is related to the cranial base length ( r = 0.712, P = .048), and also cranial base angulation ( r = 0.780, P = .023). Nasal and pharyngeal airway developed normal volume in type III. However, the cross sectional areas at the gonion level diminished by 74% ( P &lt; .001). Conclusion: Airway development is influenced by subtype of Apert suture synostosis. Type II pansynostosis Apert patients developed synchronous reduced nasal and pharyngeal airways, which is correlated with the slightly flattened cranial base. Type I bicoronal patients have a smaller nasal cavity, but normally sized hypopharynx. Yet, type III patients developed normal nasopharyngeal airway volume overall.

Apert Syndrome Management: Changing Treatment Algorithm.

The purpose of this study is to review 10 years of surgical experience in the management of Apert syndrome, focusing on an updated algorithm which includes hand reconstruction and posterior vault distraction osteogenesis (PVDO). Additionally, the authors compare PVDO, which is currently used, with fronto-orbital advancement (FOA), which was utilized in a previous algorithm. An observational retrospective study was performed on consecutive patients with Apert syndrome who underwent upper and lower limb reconstruction and craniofacial surgery between 2007 and 2017. A modified Clavien-Dindo surgical complication scale was used to stratify complications between PVDO and FOA. Demographic, surgical, and outcome data was also recorded. The blood transfusion rate between PVDO and FOA was also assessed and compared utilizing the Student t test. The present study included 69 patients with Apert syndrome (34 males and 35 females). Craniofacial surgeries were performed on a total of 38 patients. A total of 210 operations were performed on the respective upper and lower limbs of patients included in this study. A total of 18 patients underwent PVDO (n = 9) and FOA (n = 9). Posterior vault distraction osteogenesis required significantly less transfused blood volume than FOA (P < 0.05). Complication rate and length of hospital stay were similar for each procedure. An updated algorithm to treat Apert patients was implemented. Posterior vault distraction osteogenesis incorporated into an updated algorithm results in a lower blood transfusion rate.

Abstract QS3: Cranial Fossa Volume And Morphology Development In Apert Syndrome

Background: Apert patients develop normal or enlarged intracranial volume overall with growth. This study aims to trace the segmental anterior, middle and posterior cranial fossae volume, and structural morphology in these patients, in order to help discern a more focused and individualized surgical treatment plan for Apert syndrome patients. Methods: Eighty-two preoperative CT scans (Apert, n=32; control, n=50) were included in this study, and divided into 5 age related subgroups. CT scans were measured using Mimics and 3-matics software. Results: The volume of middle cranial fossa is increased and is the earliest change noted. It is increased by 45%(p=0.023) compared to controls before 6 months of age, and remains increased into adulthood (161%, p=0.016) with gradual increasing severity. The anterior and posterior cranial fossae volumes also increased, by 35%(p=0.032) and 39%(p=0.007) respectively. Increased depth of cranial fossae contributes most to the increase in cranial fossae volumes of Apert syndrome, with correlation coefficient 0.799, 0.908 and 0.888 for anterior, middle and posterior cranial fossa, respectively. The intracranial volume is increased 12%(p=0.098) across the entire test age range (0-26 years old), but only had statistical significance during the age range of 6-18 years (22%, p=0.001). Conclusions: The malformation of middle cranial fossa is an early, perhaps the initial pivotal cranial morphologic change in Apert syndrome. Increased depth of cranial fossae is an inherent character of the maldevelopment. Normalization of cranial volume and circumference overall may not achieve a normal skull structure, as it does not correct regional craniocerebral disproportion.

S12-09 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II A MACHINE LEARNING APPROACH FOR OUTCOME PREDICTION OF MIDFACIAL BIPARTITION DISTRACTION IN APERT PATIENTS

Introduction: Apert syndrome is a craniofacial syndrome characterized by deformities including hypertelorism with a negative canthal axis, exorbitism due to shallow orbits and maxillary hypoplasia resulting in a biconcave face in both midsagittal and axial planes. These abnormalities can be corrected surgically by a procedure such as midfacial bipartition distraction. Overall, surgical planning is done by the surgeon’s experience and expertise. Even though these operations seem successful based on this approach, little research has been done on the predicted outcomes of an operation based on statistical methods. This study uses various computer vision and machine learning tools to show a possible outcome of the operation. Methods: This study included pre-, and postoperative CT scans of Apert patients who had midfacial bipartition distraction. Each CT scan was cleaned and manually annotated using a set of 68 3-D sparse annotations. Then, it was aligned to the mean mesh of the Syndromic 3D Morphable Model, which is a powerful statistical model of 3D facial shape by means of Procrustes Analysis. Finally, the mesh was brought into dense correspondence to the mean face by exploiting Gaussian Processes and Non-Rigid iterative closest point (ICP) algorithms. At the end of this process, the mesh could be represented by a set of shape parameters. Results: CT scans of 17 Apert patients could be included. Every mesh was generated using only the shape parameters because every mesh in our training set had been registered. Thus, in order to predict an outcome of the operation, we can calculate a projection matrix from the pre-operative shape parameters to the post-operative parameters. In order to check the generalization ability of our model, we used a cross-validation scheme. Due to the small size of our dataset, we used the Leave-One-Out scheme. This means that we used 16 couples of pre- and postoperative CT scans to train our model and test it in the left-out sample. For the prediction, a linear regression to the shape parameters of the datasets was applied. A successful model for the prediction on the surgical outcome for midfacial bipartition distraction in Apert patients was created. Conclusion: We present a novel method for the prediction of the outcome of Midfacial bipartition distraction in Apert patients. Although the available dataset was small, we show that our model works. With this model applications such as treatment simulation could be created.

S12-12 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II MONOBLOC MINUS LEFORT II: THE ROLE OF DIFFERENTIAL DISTRACTION FOR TREATMENT OF THE APERTS CRANIOFACIAL PHENOTYPE

Introduction: Apert patients often require differential advancement of the forehead, orbits, and midface to correct fronto-orbital retrusion, lengthen the midface and nose, and close the anterior open bite. While traditionally done in stages, the Monobloc + Le Fort II distraction addresses these differential movements in a single operation. Advancement of the forehead and midface is accomplished with the monobloc, while the nose and central midface is inferiorly advanced and rotated using the Le Fort II distraction. The purpose of this study is to evaluate the skeletal 3D cephalometric changes utilizing this technique in the management of Aperts syndrome. Methods: A retrospective review was performed of the senior surgeons experience utilizing this technique in patients with Aperts syndrome. Pre and post distraction 3D CT cephalometrics were analyzed and compared to a historical published cohort of Aperts patients. Vertical and axial facial ratios were calculated before and after distraction, and these ratios were also compared between cohorts. Results: 3 patients with Aperts syndrome underwent a Monobloc + lefort II differential distraction at an average age of 8 years, and with an average length of follow up of 30 months. The following 3D cephalometric landmarks and angles were measured: Glabella, nasion, incisor midline, ANS, sella, lateral inferior orbit, SNA, SNB, occlusal plane, and maxillary mandibular incisor relationship (see chart). Average Vertical Facial Movements ANS to N: 16.3mm N to Lateral inferior orbit (LIO): 3.81mm; Average Axial Facial Movements and Ratios ANS to Sella: 31.1mm Sella to LIO: 9.05mm Sella to LIO/S to ANS: 0.290 Comparison to historical control in the literature: Lefort II distraction with zygomatic repositioning. Axial facial movement ratio: Sella to LIO/S to ANS Monobloc/Lefort II mean: 0.292 Lefort II/Zygoma Repositioning: 0.276 P = 0.43 (NS) Vertical Facial Movements Ratio: N to LIO/N to ANS Monobloc/Lefort II: 0.241 Lefort II/Zygoma Repositioning: 0.203 Conclusion: Differential distraction with the Monobloc + Lefort II allows for resolution of exorbitism, improvement in negative canthal tilt, lengthening of the nose, and closure of the anterior open bite in patients with Apert syndrome. The increased distraction and rotation of the central midface results in more normal facial ratios that are not observed with traditional monobloc distraction.

Hand Function in Apert Syndrome.

Background:The Michigan Hand Questionnaire is widely used to assess hand outcomes in congenital hand deformities. The purpose of the present study is to compare Apert syndrome hand outcomes according to Upton hand type and age stratification with age-matched unaffected controls.Methods:The Brief Michigan Hand Questionnaire was administered to 39 Apert patients after completion of the digit separation surgical regimen, and 140 age-matched unaffected controls. Patients were divided into 3 groups according to age. In group 1 (from 4 months to 7 years of age), responses were provided by parents of Apert patients, and in group 2 (from 8 to 17 years of age), patients responded with assistance from their parents, and in group 3 (18 years of age or older), responses were provided by the patients themselves. Groups were substratified according to Upton hand type (type I, II, and III). Comparisons were made among groups, subgroups, and controls.Results:Comparisons of hand types for intragroups 1, 2, and 3, did not demonstrate any statistically significant differences (P > 0.05) between hand outcomes according to Upton hand type, regardless of patient age. Comparisons between Apert patients and their age-matched controls demonstrated statistically significant differences (P < 0.05), as the control group had higher outcome scores.Conclusions:Similar hand outcomes scores were achieved by all Apert patients regardless of hand type. Following completion of the digit separation regimen, Apert patients presented hand outcome scores that were lower than those of the patients in the normative control group.