Adults with Treacher Collins Syndrome Share Comparable 3D Upper Airway Dimensions with Nonsyndromic Individuals

Abstract

Purpose: Sleep apnea symptoms, such as snoring and daytime somnolence, are commonly observed in individuals with Treacher Collins Syndrome (TCS) and may be related to airway obstruction due to micro- and retro-gnathia. This study aims to three-dimensionally evaluate the upper airway using cone-beam computed tomography (CBCT) exams of adolescents (TCS-ADOL) and adults (TCS-ADUL) with TCS compared to a nonsyndromic group (CON).

Materials and methods: Twenty-six CBCT exams were divided into three groups: TCS-ADOL (n = 7) (13.14 ± 1.67 years): CBCT exams of TCS adolescents; TCS-ADUL (n = 10) (21.80 ± 4.39 years): CBCT exams of TCS adults; and CON (n = 9) (25.33 ± 8.57 years): CBCT exams of adult nonsyndromic individuals with Class II skeletal pattern. The variables analyzed were (1) total upper airway volume; (2) nasal cavity volume; (3) total pharyngeal volume; (4) nasopharyngeal volume; (5) oropharyngeal volume; (6) pharyngeal minimal cross-sectional area; (7) pharyngeal length; and (8) pharyngeal depth. Scans were analyzed by two examiners, and intra- and inter-rater agreement was calculated. A p-value of ≤0.05 was considered significant.

Results: Although not statistically significant, the TCS-ADUL group showed decreased airway volume and minimal cross-sectional areas compared to the CON group. There were also significant differences between TCS-ADOL and TCS-ADUL, with significantly lower airway volumes in the TCS-ADOL group. Strong positive correlations were found between certain airway measurements in the TCS-ADOL group, which were not observed in adults.

Conclusions: The upper airways of adults with TCS are dimensionally similar to those of nonsyndromic individuals, despite absolute value reductions found in the syndromic group. The reduced airway in the adolescent population suggests significant potential for growth, mainly in pharyngeal dimensions.

Figure 1

Clinical characteristics of facial anomalies in individuals with Treacher Collins Syndrome in frontal (a) and lateral (b) views. Note that the patient presents with a hypoplastic midface, a prominent nose, underdeveloped zygomatic bones, and micro- and retro-gnathia.

Figure 2

Flowcharts for CBCT scans selection. The upper flowchart refers to the TCS group while the lower flowchart refers to the control group.

Figure 3

llustrative images of the delimitation areas for volumetric and linear measurements in individuals with Treacher Collins Syndrome. In images (a) (sagittal view) and (b) (3D), the green color represents the nasal cavity segmentation area, the red color represents the nasopharynx, and the blue color represents the oropharynx. In images (c) (sagittal view) and (d) (3D), the pharyngeal minimal cross-sectional area can be seen in the red pharyngeal area. Images (e) and (f) represent the pharyngeal length and pharyngeal depth acquisition, respectively. Images (g) and (h) represent the region of interest in ITK-SNAP and Dolphin Imaging, respectively.

Figure 4

Three examples of patients from groups TCS-ADOL, TCS-ADUL, and CON showing 3D segmentation images of the Class II skeletal pattern, pharyngeal depth, pharyngeal length, 3D total volume of the upper airway, and pharyngeal minimal cross-sectional area.

Figure 5

Pearson's r correlation matrix found in the three groups: positive correlations are shown in blue, and negative correlations are shown in red. The intensity of the color indicates the strength of the correlation. In (a), an adolescent individual with Treacher Collins Syndrome; in (b), an adult with Treacher Collins Syndrome; and in (c), a control individual.