Quantifying the effect of corrective surgery for trigonocephaly: A non-invasive, non-ionizing method using three-dimensional handheld scanning and statistical shape modelling

Abstract

Trigonocephaly in patients with metopic synostosis is corrected by fronto-orbital remodelling (FOR). The aim of this study was to quantitatively assess aesthetic outcomes of FOR by capturing 3D forehead scans of metopic patients pre- and post-operatively and comparing them with controls. Ten single-suture metopic patients undergoing FOR and 15 age-matched non-craniosynostotic controls were recruited at Great Ormond Street Hospital for Children (UK). Scans were acquired with a three-dimensional (3D) handheld camera and post-processed combining 3D imaging software. 3D scans were first used for cephalometric measurements. Statistical shape modelling was then used to compute the 3D mean head shapes of the three groups (FOR pre-op, post-op and controls). Head shape variations were described via principal component analysis (PCA). Cephalometric measurements showed that FOR significantly increased the forehead volume and improved trigonocephaly. This improvement was supported visually by pre- and post-operative computed mean 3D shapes and numerically by PCA (p < 0.001). Compared with controls, post-operative scans showed flatter foreheads (p < 0.001). In conclusion, 3D scanning followed by 3D statistical shape modelling enabled the 3D comparison of forehead shapes of metopic patients and non-craniosynostotic controls, and demonstrated that the adopted FOR technique was successful in correcting bitemporal narrowing but overcorrected the rounding of the forehead.

Lack of association of cranial lacunae with intracranial hypertension in children with Crouzon syndrome and Apert syndrome: a 3D morphometric quantitative analysis

“…A similar study using 3DR would be interesting in single-suture synostosis; however, our unit (in keeping with practice with many of the larger craniofacial units worldwide) does not routinely undertake CT scanning for single-suture cases in the absence of other concerns [13,14] which limits the dataset available for analysis. 3D optical imaging, which avoids ionizing radiation, can reliably assess head shape in children with craniosynostosis [15,16] but does not allow delimitation of cranial lacunae. Another issue is regarding age at index scan, which varied considerably in our study group.…”

Statistical shape modelling to aid surgical planning: associations between surgical parameters and head shapes following spring-assisted cranioplasty

“…In recent years, computer-assisted analysis of 3D medical image data has been employed to improve the head shape description [ 9 – 12 ] and to aid in the diagnosis of craniosynostosis [ 13 – 19 ] as well as in the evaluation of surgical outcomes [ 20 – 23 ]. With the aim of facilitating cranio-maxillofacial surgery, statistical shape modelling (SSM) has been used in virtual surgery planning [ 24 – 28 ] as well as in the design of pre-fabricated templates [ 29 – 31 ], surgical guides [ 32 , 33 ] and cranial implants [ 34 , 35 ] to achieve desired patient-specific post-operative outcomes on-table.…”

The Postoperative Morphometrics of Orbital and Maxillary Area for Craniosynostosis

“…Rodriguez-Florez et al 7 quantitatively evaluates the aesthetic outcome of FOA by comparing to the control group before and after surgery using a hand-held scanner to scan the forehead…”