Sphenoid Bone Structure and Its Influence on the Cranium in Syndromic Versus Nonsyndromic Craniosynostosis

The influence of orbital architecture on strabismus in craniosynostosis

PURPOSE

To better characterize the correlation of bony orbital dysmorphology with strabismus in craniosynostosis.

METHODS

The medical records of patients with craniosynostosis with and without strabismus seen at Rady Children's Hospital (San Diego, CA) from March 2020 to January 2022 were reviewed retrospectively in this masked, case-control study. Computed tomography scans of the orbits were analyzed to obtain dimensions of the orbital entrance and orbital cone. Primary outcome was correlation of strabismus with orbital measurements.

RESULTS

A total of 30 orbits from 15 patients with strabismus and 15 controls were included. Craniofacial disorders included in the study were nonsyndromic craniosynostosis (63%), Crouzon syndrome (13%), Apert syndrome (13%), and Pfeiffer syndrome (10%). Orbital index (height:width ratio) (P = 0.01) and medial orbital wall angle (P = 0.04) were found to differ significantly between the strabismus and control groups.

CONCLUSIONS

In our small cohort, bony orbital dimensions, including the ratio of orbital height to width and bowing of the medial orbital wall, were associated with strabismus in craniosynostosis.

A COMPARATIVE STUDY OF MIPPO AND MDLIN APPLIED TO THE TREATMENT OF DISTAL TIBIAL FRACTURES

Objective: This study aims to analyze the clinical treatment effects of the minimally invasive percutaneous plate osteosynthesis (MIPPO) and multi-directional locking intramedullary nail (MDLIN) techniques in patients with distal tibial fractures. Methods: A total of 124 patients with distal tibial fractures, admitted to the People’s Hospital of Zhongjiang County from February 2019 to January 2020, were selected as the research subjects. They were randomly divided into groups ([Formula: see text]). The control group received MIPPO treatment, the observation group received MDLIN treatment, and the postoperative therapeutic effects and complications in the two groups were compared. Results: The patients in the observation group had shorter operative time and lower intraoperative blood loss than those in the control group ([Formula: see text]). The two groups had no significant differences in fracture healing time, complete weight bearing time, or functional recovery. The postoperative complication rate in the cases of the observation group was significantly lower than that of the control group ([Formula: see text]). Conclusion: Both techniques can achieve sufficient therapeutic effects; however, the MDLIN technique has certain advantages, including significantly fewer complications, lower intraoperative blood loss, and shorter operative durations compared to the MIPPO technique.

Orbital and Periorbital Dysmorphology in Untreated Pfeiffer Syndrome

BACKGROUND

Visual impairment secondary to orbital and periorbital dysmorphology is frequent in Pfeiffer syndrome patients. The etiopathogenesis of this aberrancy, however, remains unclear.

METHODS

Untreated Pfeiffer syndrome patients (n = 31) and normal control subjects (n = 43) were compared. Craniometric and volumetric analyses related to the orbital and periorbital anatomy were performed using Materialise (Leuven, Belgium) software.

RESULTS

Overall, orbital cavity volume of Pfeiffer patients is reduced by 28 percent (p < 0.001), compared to normal, starting before 3 months of age (p = 0.004). Globe volume was diminished by 10 percent (p = 0.041) before 3 months of age, yet tended to catch up thereafter. However, the retrobulbar soft-tissue volume remained smaller beyond 1 year of age (17 percent, p = 0.003). Globe volume projection beyond the bony orbit increased in all observed ages (82 percent, p < 0.001). The volumes of sphenoid bone, maxilla, and mandible proportionately were restricted by 24 to 25 percent (p = 0.003 to 0.035) before 3 months of age. The volume of maxilla and mandible gradually approximate normal; however, the sphenoid bone volume in Pfeiffer patients remains less than normal (p = 0.002) into childhood. The anteroposterior length of both the zygoma and the maxilla was reduced by 14 percent (p < 0.001). Anterior positioning of the zygoma is less by 23 percent (p < 0.001) in Pfeiffer patients overall, with anterior positioning of maxilla reduced similarly by 23 percent (p < 0.001).

CONCLUSIONS

Pfeiffer syndrome patients develop decreased retrobulbar soft-tissue and globe volume, along with a restricted orbital cavity volume in infancy. Significant hypoplasia of the sphenoid bone is associated with more severe central facial (maxilla) retrusion, compared to lateral facial structures (zygoma).

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Does different cranial suture synostosis influence orbit volume and morphology in Apert syndrome?

This study was performed to compare the orbital and peri-orbital morphological variations in Apert syndrome patients with different cranial vault suture synostosis, so as to provide an anatomic basis for individualized surgical planning. Computed tomography scans of 57 unoperated Apert syndrome patients and 59 controls were subgrouped as follows: type I, bilateral coronal synostosis; type II, pansynostosis; type III, perpendicular combinations of cranial vault suture synostoses. Orbit bony cavity volume was significantly reduced in type I and type II, by 19% (P < 0.001) and 24% (P < 0.001), respectively. However, the reduction of orbital cavity volume in type III did not reach statistical significance. Globe volume projection beyond the orbital rim, however, increased by 76% (P < 0.001) in type III, versus an increase of 54% (P < 0.001) in type I and 53% (P < 0.001) in type II, due to different ethmoid and sphenoid bone malformations. Maxillary bone volume was only significantly reduced in type I bicoronal synostosis (by 24%, P = 0.048). Both type I and type II developed relatively less zygoma and sphenoid bone volume. Different cranial vault suture synostoses have varied influence on peri-orbital development in Apert syndrome. Instead of mitigating the abnormalities resulting from bicoronal synostosis in type I, additional midline suture synostosis worsens the exorbitism due to a more misshaped ethmoid.

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 < .001), and narrower width ( r = 0.727, P < .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 < .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.