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Use of Axial CT Scans to Assess Early Postnatal Development of the Internal Nares: a Test of Reliability
Author(s) -
Gupta Anmol,
Meaike Joshua,
Pagano Anthony,
Curcio Daniella Franco,
Som Peter,
Laitman Jeffrey T.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.780.7
Subject(s) - craniofacial , reproducibility , anatomy , landmark , morphometrics , orthodontics , cartography , medicine , biology , mathematics , statistics , geography , psychiatry , fishery
Human newborns are exclusively nasal breathers due to an anatomical configuration of the aerodigestive tract, similar to those of non‐human primates. Thus, choanal stenosis and other upper airway obstructions may be serious conditions among infants. Morphometric studies lack standardized methods to investigate size, proportion and position of the internal nares in relation to the skull. This study tests the hypothesis that 3D coordinates for landmarks and craniometric points taken on axial CT scans can be reliably used to assess choanal aperture and craniofacial anatomy via 3D geometric morphometrics. We used the computer program Osirix® to identify 16 landmarks on 23 axial scans of monkey skulls ( Macaca mulatta ) as a model to test accuracy. Two observers underwent four training sessions to plot the landmarks on specimens apart from the study sample. Each observer performed three assessments per specimen and no specimen was evaluated twice in the same day. We assessed landmark accuracy using Generalized Procrustes Analysis by optimal superimposition, scaling by Centroid Size and measured the procrustes distances to interpret data. The obtained interobserver errors were higher than 5%, which indicates that 3D landmark coordinates obtained from axial slices generate considerable interobserver variation and low reproducibility of measurements between structures or bone regions situated in different planes. There was no significant difference in interobserver accuracy in identifying standard craniometric points or regional landmarks assessed by ANOVA. This study indicates that collection of 3D coordinates from axial slices to assess the complex morphology of the choanae and how it changes with growth and development involves intrinsic errors of measurement that must be addressed and controlled when performing geometric morphometric analysis. Next step of this project is using volume rendered 3D CT scans and obtain coordinates for the same landmarks to determine interobserver variability, assess accuracy, and validate reproducibility. Support or Funding Information Icahn School of Medicine's Summer Student Investigator Program Award/CNPq ‐ Brazilian National Counsel of Technological Development