Faculty Bibliography

Background/Purpose: Distraction osteogenesis is indicated in patients with syndromic craniosynostosis with severe midface hypoplasia and proptosis. Pre-adolescent intervention is indicated when eye closure is limited, to prevent long-term ocular damage. The long-term stability of proptosis correction by Le Fort III distraction in this population has not been previously reported. Methods/Description: A retrospective review was conducted to identify patients with syndromic craniosynostosis treated by Le Fort III distraction prior to age 10, with cephalometric films available at least 3 years after treatment. 15 patients were identified (9 male, 6 female; age 4.9+/-1.5 years) with diagnoses of Crouzon(7), Apert(6), and Pfeiffer(2) syndromes. Lateral cephalometric radiographs at pre-surgery(T1), immediate post-distraction(T2), short-term post-distrac-tion(T3), and long-term(T4) were traced manually to identify the most inferior point on the orbital rim (orbitale), and the most anterior point on the globe. Tracings were superimposed on sella-ethmoid using the best-fit of cranial base details. Changes were measured using an x,y coordinate system with sella as the origin, and 7degree below the T1 sella-nasion line as the horizontal plane. Proptosis severity was defined as the horizontal distance between globe and orbitale. All measurements were corrected to a magnification factor of 0%. Changes in landmark location and proptosis severity were assessed by paired t-tests. Results: Orbitale advanced 10.2+/-3.8mm (p<0.001) horizontally from T1 to T2, with a superior movement of 2.1+/-3.5mm (p 0.02). The globe advanced 3.0+/-3.2mm (p 0.03) with no significant change in vertical position (p 0.539), resulting in a significant decrease in proptosis (-7.265.1mm, p<0.001). From T2 to T3 (1.160.7 years), orbitale remained stable horizontally (p 0.595), with minor inferior movement (-1.661.8mm, p 0.05). Globe position was stable horizontally (p 0.363) and vertically (p 0.436), as was proptosis correction (p 0.721). At long-term follow-up (T2 to T4, 4.87+/-0.93 years), orbitale remained stable horizontally (p 0.522) with no significant vertical change compared to T3 (p 0.113). Globe position was stable vertically (p 0.350); however, significant anterior globe movement occurred (+2.2+/-2.6mm, p 0.003) with an associated increase in proptosis (+1.9+/-2.7mm, p 0.015). Despite this, proptosis remained decreased by 5.3mm (95% CI 2.9mm, 7.6mm) at T4 compared to T1. Conclusions: Bony advancement of the orbital rim by Le Fort III distraction osteogenesis in pre-adolescent patients was stable 5 years post-distraction. Initial advancement of the orbit was associated with minor advancement of the globe, though considerable individual variation was noted. While proptosis was improved by treatment at all time-points, phenotypic relapse of 2mm was observed 5 years post-treatment, reinforcing the need for over-correction. At 5 year follow-up, 2.9 to 7.6 mm of proptosis correction remained

Background/Purpose: The aim of this study is to perform a cephalometric evaluation of the craniofacial skeleton of patients with TCS. Methods/Description: Retrospective single institution review of all patients (N= 104) with TCS and a preoperative cephalogram was conducted (30 patients). Patients were divided into three groups based on their ages: infancy (mean 0.62 yr; range:0.01-2.2 yrs) adolescence (mean 7.91 yr, range:5.18-11.26 yrs) and post adolescent-young adulthood (mean 17.04 yr; range:15.49-21.36 yrs). Right and left sides were evaluated separately if asymmetry was noted to be present (44 sides). The cephalometric variables were compared to Bolton and Moyers norms and also to each other using ANOVA and student's t-test. Results: All maxillary and mandibular measurements were significantly different from normative values with the exception of SNA and upper gonial angle (Na-Go-Me). SNB, SNPg angles were severely decreased and Pg (Pg-NB) was significantly retruded (p<0.001). Gonial angle (Ar-Go-Me) was significantly wider than normal as lower gonial angle (Ar-Go-Na) and antegonial angles were significantly increased (p<0.001) in all three age groups. There was no difference among the groups in terms of increased antegonial angles. All vertical plane angles (SN-MP, SN-GoGN, FH-MP, SN-PP, PP-MP) were increased significantly as well (p<0.001). Correspondingly, the ratio between lower anterior face height and total face height was significantly higher, while posterior face height to anterior face height was significantly decreased (p<0.001). More than half of the patients (N= 17/30) possessed a parasagittal symphyseal notch at the anterior surface of the chin. The depth and width of this notch were increased from infancy to adolescence (p<0.01). Accordingly, symphysis inclination (SN-Symp.) increased significantly over time (p<0.01). The maxillary posterior region showed decreased height (p<0.01). Our findings suggest that the maxillo-mandibular deformity demonstrates what we have termed a 'parasagittal orbito-maxillo-zygomatic cleft' which is aligned along the path of maximum mandibular atresia (diminished or missing coronoid, condylar processes and rami. Conclusions: When comparing cephalometric values in patients with TCS to Bolton and Moyers, all structures showed varying degrees of deformation or dislocation with the exception of maxillary sagittal position. These changes were most prevalent in the posterior maxillae, mandible, symphysis and antegonial area of the mandible. Certain skeletal changes did not show variance from infancy to adulthood, such as maxilla-mandibular angle and Wits value, however changes of the symphysis region became more severe over time. Further, soft tissue facial convexity increased severely in all growth periods