Skeletal changes after midface surgery in patients with craniofacial deformities: a three-dimensional quantification method.

To determine the skeletal changes after midface surgery in patients with syndromic craniosynostosis who underwent Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB). This was a retrospective study including 75 patients: 33 treated by LFIII, 29 by MB, and 13 by FB. Twenty-five had a diagnosis of Apert, 39 Crouzon, and 11 craniofrontonasal syndrome. A three-dimensional mesh was created from the preoperative scan and registered to the postoperative scan to visualise the advancement. LFIII at age 7-12 years effectuated a higher mean advancement in the maxillary (15.5 mm) and zygomatic (7.6 mm) regions when compared to ≥13 years (10.2 mm and 5.5 mm). After MB, mean advancement of the fronto-orbital region was higher at <7 years (16.4 mm), and similarly lower at ages 7-12 (13.8 mm) and ≥13 (12.5 mm). The mean preoperative inter-dacryon distance (34.4 ± 4.4 mm) was reduced by 8.7 ± 4.2 mm after FB without distraction (n = 10). More advancement was seen when midface surgery was performed at a younger age, due to more severe cases and a desire for overcorrection. The highest mean advancement was observed in the fronto-orbital region. Antero-inferior rotational movement was seen after all three techniques.

Hyoid bone morphology in patients with isolated robin sequence - A case-control study utilizing 3D morphable models.

Background: Abnormalities of the hyoid bone are associated with impairment of oropharyngeal functions including feeding, swallowing, and breathing. Few studies have characterized anatomic abnormalities of the hyoid in patients with Robin sequence (RS), e.g. a less mineralized and voluminous hyoid. The purpose of this study was to compare normal hyoid bone morphology and hyoid bone morphology in children with isolated RS. Methods: Three-dimensional (3D) reconstructions of the hyoid bone were obtained from CT-imaging of children with RS and unaffected controls. A 3D morphable model was constructed using Principal Component Analysis (PCA). Partial least squares - Discriminant Analysis (PLS-DA) and multivariate analysis of variance (MANOVA) were used to characterize and compare hyoid shape differences between patients with RS and an age-matched control group. Results: The study included 23 subjects with RS (mean age 9.8 ± 10.3 months) and 46 age-matched control samples. A less voluminous hyoid was observed for the RS group with a larger lateral divergence of the greater horns compared to controls (MANOVA, p-value<0.001). The first shape variable from the PLS-DA model showed a significant correlation for the observed variance between the two groups (Spearman R = -0.56, p-value<0.001). The control samples and 151 CT-scans of subjects up to age 4 years were used to create a 3D morphable model of normal hyoid shape variation (n = 197, mean age 22.1 ± 13.1 months). For the normal 3D morphable model, a high degree of allometric shape variation was observed along the first principal component. Conclusions: The 3D morphable models provide a comprehensive and quantitative description of variation in normal hyoid bone morphology, and allow detection of distinct differences between patients with isolated RS and controls.

A comparison of airway interventions and gastrostomy tube placement in infants with Robin sequence.

The purpose of this study was to evaluate feeding impairment following non-operative or operative management of airway obstruction in a large series of infants with Robin sequence (RS) by rate of G-tube placement. A retrospective study was conducted at Boston Children's Hospital including 225 patients (47.1% female) with RS treated between 1976 and 2018. Subjects were grouped by intervention required for successful management of airway obstruction: non-operative only (n = 120), tongue-lip adhesion (TLA, n = 75), mandibular distraction osteogenesis (MDO, n = 21), or tracheostomy (n = 9). The operative group had a higher rate of G-tube placement (58.1%) than the non-operative group (28.3%, P < 0.0001). Subjects in the TLA and tracheostomy groups had higher odds of G-tube placement than subjects in the MDO group: odds ratio (OR) 5.5 (95% confidence interval (CI) 1.8-17.3, P = 0.004) and OR 27.0 (95% CI 3.2-293.4, P = 0.007), respectively. Syndromic patients and those with gastrointestinal anomalies also had higher odds of G-tube placement: OR 3.5 (95% CI 1.7-7.2, P = 0.001) and OR 5.9 (95% CI 1.6-21.0, P = 0.007), respectively. Infants with RS who require an airway operation and those with a syndromic diagnosis or gastrointestinal anomalies are more likely to require placement of a G-tube. Of the operative groups, MDO was associated with the lowest G-tube rate, compared to TLA and tracheostomy.