Evaluation of hard palate and cleft morphology in neonates with Pierre Robin Sequence and Cleft Palate Only

Abstract

Objectives: This study aimed to establish a fully digital measurement protocol for standardizing the description of hard palate and cleft morphology in neonates with an isolated cleft palate (CPO) and Pierre Robin sequence (PRS).

Materials and methods: A total of 20 digitized plaster models of neonates with CPO and 20 digitized plaster models of neonates with PRS were retrospectively investigated. For the control group, the hard palate was segmented from 21 pre-existing 1.5 T MRI datasets of neonates and exported as an STL file. The digital models were marked with predefined reference points by three raters. Distance, angular, and area measurements were performed using Blender and MeshLab.

Results: Neonates with CPO (20.20 ± 2.33 mm) and PRS (21.41 ± 1.81 mm) had a significantly shorter hard palate than the control group (23.44 ± 2.24 mm) (CPO vs. control: P < .001; PRS vs. control: P = .014). Notably, neonates with PRS (33.05 ± 1.95 mm) demonstrated a significantly wider intertuberosity distance than those with CPO (30.52 ± 2.28 mm) (P = .012). Furthermore, there were also significant differences measured between the cleft and control groups (25.22 ± 2.50 mm) (P < .001).

Conclusions: The data from this study demonstrate the feasibility of using MRI datasets to generate digital models of the hard palate. The presence of a cleft palate leads to pronounced adaptations of the total palatal surface area, dorsal width, and length of the hard palate. Mandibular retrognathia and altered tongue position in PRS, as opposed to CPO, might further impact palatal morphology and intertuberosity distance.

Keywords: MRI; Pierre Robin sequence; cleft palate only; digital orthodontics; paediatric radiology.

FIGURE 1

(A, B) display digitized plaster models of a neonate with PRS. (C, D) illustrate a digital model from the control group, segmented from a 1.5 T MRI dataset.

FIGURE 2

A, An illustration of the geometric area approximation of the total area (A1, triangle) and the cleft area (A2, triangle). B, An illustration of the geometric area approximation of the total area (A3, trapezoid and triangle); an illustration of the geometric area approximation of the cleft area (A4, trapezoid and triangle). C, The marked mesh area (orange) of the palatal surface and constructed cleft surface (grey) in Blender. D, The duplicated and segmented palatal and surface for export from Blender. E, The occlusal view of the digitized cast of isolated cleft palate with the predefined reference points I (incisivum), C/C′ (canine prominence right/left), T/T′ (tuber maxillae point right/left), S (foremost point of the cleft region), D/D′ (dorsal boundary of the cleft right/left), G/G′ (waypoint; half distance between C and I resp. C′ and I), and L/L′ (waypoint, half distance between D and S or D′ and S) and distances IT or IT′ (light blue), ID or ID′ (dark red), SD or SD′ (yellow), and ST or ST′ (green). F, The oblique view plotted angles ∡TIT′, ∡DSD′, ∡TID, and ∡D′IT′. G, An illustration of the hard palate's arch angle (BFCRidge). H, An illustration of the arch angel cleft (BFCCleft).

FIGURE 3

A, Angular measurements of the digitized models. BFCRidge, arch angle of the entire palate measured in all three groups. All other parameters describe the cleft area and were only measured in the CPO and PRS groups. BFCCleft, arch angle of the cleft; DSD, opening angle of the cleft; BFCCleft, arch angle of the cleft; DIT and T′ID′, cleft opening angle on the right and left sides. B, Distance measurements of the digitized models. CC′, intercanine distance; IT/IT_, distance between I and T/T′; TT′, posterior palatal width; ITT_, sagittal length of the hard palate. All distances are measured in mm. *P < 0.05, ***P < 0.001. C, Area measurements of the digitized models. A1 and A3, area approximation of the total hard palate; A2 and A4, area approximation of the cleft area; MeasAreapalate, exact surface of the entire palate; MeasAreacleft, exact surface of the cleft region. *P < .05, **P < .01.