A 3D-CBCT Volumetric Analysis of Cervical Vertebrae Angulation and Airway Dimensions

Abstract

Aim: To evaluate the relationship between airway dimensions and cervical vertebrae angulations in dental patients using three-dimensional cone beam computed tomography (3D-CBCT) technology. Materials and Methods: Pre-treatment CBCT scans and cephalometric radiographs were measured for 59 patients (mean age 22±2.3yrs.) using the Dolphin3D software system (version 11.7; Dolphin Imaging & Management Solutions, Chatworth, CA) to record airway dimensions and cervical vertebral angulations. All CBCT images were acquired using the same standard protocol for collection using the iCAT CBCT Unit (Imaging Sciences International, Hatfield, PA): 13cm field of view, 0.4mm voxel size, 8.9sec scan time. Intraclass Correlations (ICC) were performed on duplicate measurements of 10 CBCT scans after a two-week interval to assess reliability. P-value and Pearson correlation coefficients were used to statistically assess the relationship between vertebral angulations and airway dimensions. Results: ICC values from the reliability assessment were >0.90. Pearson correlation coefficients were categorized based on confidence level as follows: high (>0.75 or <-0.75), moderate (0.5 to 0.74 or -0.5 to -0.74), or weak (0.3 to 0.49 or -0.3 to -0.49). No high/moderate correlations were observed. Weak correlations (p<0.05) were observed between the nasopharyngeal volume and the soft tissue thickness at CV1(-0.47) and CV2(-0.34). A weak correlation was observed between the nasal cavity volume and S-N (+0.41) as well as ANS-PNS(+0.38). A weak correlation was observed between the total airway volume and the soft tissue thickness at CV2(-0.34). Conclusion: The soft tissue thickness of the posterior wall of the airway at the level of cervical vertebrae-2 appears to have a weak, negative correlation with several upper airway parameters and total airway volume. Soft tissue thickness of the posterior pharyngeal wall is crucial for dental clinicians to analyze prior to some procedures such as orthognathic surgery and orthodontic treatment that involve growth modification and jaw positioning, as it may have an association with decreased airway volume. Clinical Significance: The relationship between cervical vertebrae angulation, airway, and craniofacial morphology is a complex aspect of human anatomy. In dentistry, it is crucial that clinicians recognize the vital role cervical vertebrae angulation and airway interact in relation to craniofacial morphology. Knowledge of these interconnections will significantly inform treatment planning for multiple oral health conditions such as malocclusions, jaw discrepancies, and temporomandibular joint disorders.