A Three-Dimensional-Based Morphometric Analysis of a Standardized Overcorrection Technique for Fronto-Orbital Advancement in Metopic Craniosynostosis

Abstract

Introduction The concept of “overcorrection” for trigonocephaly has been reported to achieve both anterior cranial fossa expansion and normalization of craniofacial form. The purpose of this study is to describe in detail a standardized technique to fronto-orbital advancement utilizing the concept of “overcorrection” and objectively evaluate intermediate results. Methods This retrospective study included patients with isolated metopic synostosis who underwent surgery via the proposed surgical technique and age and sex-matched unaffected controls. Craniofacial morphometric analysis was performed on pre-, immediate post-, and intermediate postoperative (>2 years) three-dimensional (3D)-rendered computed tomographic (CT) scans and photographs. Key CT-based measurements included interzygomaticofrontal suture distance (IZFS), endocranial bifrontal angle (ECA), and temporal expansion. 3D photogrammetry was performed using established measurements and associated Z-scores converted. A Paired t-test and analysis of variance were performed when appropriate. Results Forty-one patients were included. A comparison of pre- and immediate postoperative CT scans demonstrated statistically significant increases in all measurements. Subset analysis of 12 patients with intermediate follow-up (age: 39.6 ± 3.6 months) demonstrated significant differences from preoperative values except for IZFS, which decreased from immediate postoperative values and was smaller than age- and sex-matched controls. 3D photogrammetry demonstrated a mean Z-score above the norm for frontal breath. 3D photogrammetry is also positively correlated with CT-based measurements. Conclusions This standardized “overcorrection” approach for trigonocephaly can provide the appropriate changes to maintain a normal ECA despite a reduction in bifrontal width over time. 3D photogrammetry positively correlated with CT-based measurements and may provide useful information when following patients clinically. Long-term follow-up assessment to determine the necessary degree of overcorrection at skeletal mature is needed.

Machine Learning in Metopic Craniosynostosis: Does Phenotypic Severity Predict Long-Term Esthetic Outcome?

“…Reoperation rates are cited as high as 28%,7 with most studies likely underestimating their true reoperation rates due to insufficient follow-up 8,9. The observed rates of esthetic relapse associated with fronto-orbital advancement have prompted many teams to incorporate overcorrection of the fronto-orbital bandeau into their surgical technique, thereby over-expanding the temporal regions and aggressively advancing and widening the fronto-orbital bar within the constraints of the available soft tissue envelope 5,10…”

“…8,9 The observed rates of esthetic relapse associated with fronto-orbital advancement have prompted many teams to incorporate overcorrection of the fronto-orbital bandeau into their surgical technique, thereby over-expanding the temporal regions and aggressively advancing and widening the fronto-orbital bar within the constraints of the available soft tissue envelope. 5,10 An additional element potential influencing metopic esthetic outcomes is the impact of preoperative phenotypic severity. Previous studies attempting to characterize the relationship between preoperative severity and long-term esthetic outcomes have relied on clinical photographs evaluated by medical students 11 or reductive 2-dimensional measurements from 3-dimensional rendered images.…”

3D Analysis of the Cranial and Facial Shape in Craniosynostosis Patients: A Systematic Review

“…Frontal width was described in 6 publications 20,37,40,52,59,60 of which 4 publications described frontotemporal distance 37,40,59,60 . In addition, 2 publications described the interfrontoparietal–interparietal ratio, which focuses on the relative width of the forehead compared with the parietal width 20,52 …”

Orbital Foraminal Morphometrics in Nonsyndromic Unilateral Coronal Craniosynostosis

“…Previous studies have attempted to characterize the morphological bony changes associated with nonsyndromic UCS. [17][18][19][20] Unilateral coronal synostosis has been described with characteristic morphologic associations, including ipsilateral frontal flattening, supraorbital rim retrusion, anterior displacement of midface structures, and decreased orbital size. 5,21 Prior studies have not evaluated the morphometrics of important orbital foramina structures in patients with UCS.…”