Background: Patients with Apert syndrome frequently experience breathing problems alongside characteristic malformations. The relatively under-investigated Apert mandible position, development, and morphology may be implicated. Three-dimensional morphable models (3DMMs) can represent, quantitatively analyze, and identify parameters for shape of similar, 3-dimensional, biological objects. This study aims to develop an Apert mandible 3DMM, investigate effects of age, sex, and genetic mutation on Apert mandibular shape, characterize Apert mandibular growth by age. Methods: High-quality Apert head computerized tomography (CT) scans without previous mandibular surgery, taken 1987 to 2020 were sourced from 2 European pediatric specialist hospitals. Two Apert mandible 3DMMs were constructed from the scans using a standardized pipeline: a size and shape version, and a shape-only version. Subgroup analyses included ages 0 to 4 and 11 to 17 years. Results: Two hundred thirty-eight Apert CT scans, from 103 patients aged 0.1 to 23.2 years, were used to develop 2 Apert mandible 3DMMs. All groups in both models showed no patterns for sex or genetic mutation ( Ser252Trp or Pro253Arg ) in t-Distributed Stochastic Neighbour embedding and true age was significantly positively correlated with model-predicted age (r=0.45–0.94, P <0.05). First principal component visualization of the Apert mandible 3DMMs suggested macroscopic shape differences compared with the healthy mandible. Conclusions: Apert mandible 3DMMs were successfully constructed and characterized for growth by age. The Apert mandible 3DMMs suggested macroscopic shape differences but no variation in shape according to sex or genetic mutation. Further research will quantify Apert and healthy mandible shape differences. Apert 3DMMs have potential for used in automated diagnosis of Apert syndrome and personalized surgical planning.
Ramjeeawon et al. (Mon,) studied this question.