Table 1 Definition of parameters used in the study
Parameter | Plane | Boundaries |
|---|---|---|
The nasal cavity (Fig. 2) | Sagittal Plane Coronal Plane | Anterior: by the line connecting the anterior nasal spine (ANS) – the tip of the nasal bone –Nasion (N) Posterior: the line extending from floor Sella (S) – Posterior nasal spine (PNS) Superior: the line connecting the N – S Inferior: the line extending from ANS –PNS the outline of the nasal cavity in a section including the maxillary first molar bifurcations area starting at the crista galli, running downward toward the nasal floor and passing through the sidewalls of the right and left nasal cavity |
The nasopharynx (Fig. 3A, B) | Sagittal Plane | Anterior: the line extending from S –PNS Posterior: the line extending from S – tip of the odontoid process Inferior: the line extending from PNS – tip of the odontoid process |
The oropharynx (Fig. 3C, D) | Sagittal Plane | Anterior: the line extending from PNS – symphysis of the mandible Posterior: the line extending from the tip of the odontoid process – anterior-inferior border of C3 Superior: the line extending from PNS – tip of the odontoid process Inferior: the line extending from the anterior -inferior border of C3- symphysis of the mandible |
The hypopharynx (Fig. 3E, F) | Sagittal Plane | Anterior: symphysis of the mandible Posterior: the line extending from the anterior-inferior border of C3– anterior-inferior border of C4 Superior: the line extending from the anterior -inferior border of C3- symphysis of the mandible Inferior: the line extending from the anterior -inferior border of C4- symphysis of the mandible |
Total airway (Fig. 4A, B) and the boundary to detect the most constricted area of the airway (Fig. 4C, D, E) | Sagittal Plane | Anterior: the line extending from S –PNS – symphysis of mandible Posterior: the line extending from S - the tip of the odontoid process – anterior-inferior border of C4 Inferior: the line extending from the anterior-inferior border of C4- symphysis of the mandible |
Soft tissue thickness opposite to Basion (Ba) (Fig. 5A) | Sagittal Plane | The prevertebral soft tissue thickness as a distance parallel to FH plane from the most infero-posterior point on the anterior rim of foramen magnum :Basion (Ba) |
Soft tissue thickness opposite to Atlas (Fig. 5A) | Sagittal Plane | The prevertebral soft tissue thickness as a distance parallel to FH plane from the most anterior point on the anterior arch of the atlas vertebrae (AA) |
Soft tissue thickness opposite to CV2 (Fig. 5A) | Sagittal Plane | The prevertebral soft tissue thickness as a distance parallel to FH plane from the most inferior-anterior point of CV2 (CV2ia) |
Soft tissue thickness opposite to CV3 (Fig. 5A) | Sagittal Plane | The prevertebral soft tissue thickness as a distance parallel to FH plane from the most inferior-anterior point of CV3 (CV3ia) |
Soft tissue thickness opposite to CV4 (Fig. 5A) | Sagittal Plane | The prevertebral soft tissue thickness as distance parallel to FH plane from the most inferior-anterior point of CV4 (CV4ia) |
Inter-molar (Fig. 5B) | Coronal Plane | Distance between the disto-buccal cusps of right and left first molars, parallel to FH plane |
Inter-premolar (Fig. 5C) | Coronal Plane | Distance between the disto-buccal cusps of right and left first pre-molars, parallel to FH plane |
Inter-canine (Fig. 5D) | Coronal Plane | Distance between the cusp Tips of right and left canines, parallel to FH plane |
Maxillary width (Fig. 5B) | Coronal Plane | The point located at the depth of concavity of the lateral maxillary contour, at the junction of the maxilla and the zygomatic buttress, parallel to FH plane |