Skip to main content

Table 1 Study landmarks and reference planes

From: Quantification of skeletal asymmetries in normal adolescents: cone-beam computed tomography analysis

Landmarks

 

Definition

Sagittal slice

Axial slice

Coronal slice

Dental

Mx1

Maxillary central incisors

Incisal contact point of the maxillary central incisors

Inferior-most point

Contact point

Incisal embrasure

 

Md1

Mandibular central incisors

Incisal contact point of the mandibular central incisors

Inferior-most point

Contact point

Incisal embrasure

 

Mx3R and Mx3L

Maxillary canine

Cusp tip of the maxillary canine

Inferior-most point

First point that appears

Inferior-most point

 

Md3R and Mx3L

Mandibular canine

Cusp tip of the mandibular canine

Superior-most point

First point that appears

Superior-most point

 

Mx6R and Mx6L

Maxillary first molar

Mesiobuccal cusp tip of the maxillary first molar

Inferior-most point

First point that appears

Middle-inferior-most point

 

Md6R and Mx6L

Mandibular first molar

Buccal groove of the mandibular first molar

Inferior-most point between the buccal cusps

First point that appears

Superior-most point in line with the buccal cusps

Midface

ANS

Anterior nasal spine

The most anterior midpoint of the anterior nasal spine of the maxilla

Lateral-most point

Superior-most point

First point that appears

 

PNS

Posterior nasal spine

The most posterior midpoint of the posterior nasal spine of the palatine bone

Lateral-most point

Inferior-most point

First point that appears

 

OrR and OrL

Orbitale

The most inferior point on the infraorbital rim of the maxilla

Inferior-most point of the infraorbital rim

Anterior-most point

Inferior-most point of the infraorbital rim

 

FZSR and FZSL

Frontozygomatic suture

The most superior and medial point on the frontozygomatic suture

Superior-most point

Anterior-most point

Medial-superior most point

 

FPMR and FPML

Frontal process of maxilla

Intersection of the frontal process of the maxilla, frontal bone and lacrimal bone

Superior-most point

Anterior-most point

Medial-superior most point

Mandible

Me

Menton

The most inferior midpoint of the chin on the outline of the mandibular symphysis

Inferior-most point

First point that appears

Middle-most point along the inferior border

 

Pg

Pogonion

The most anterior midpoint of the chin on the outline of the mandibular symphysis

Inferior-most point

Superior-most point

First point that appears

 

GoR and GoL

Gonion

The midpoint on the angle of the mandible, half way between the corpus and ramus

Middle-most point along the angle of the mandible

Middle-inferior-most point

Middle-inferior-most point

 

CdSR and CdSL

Condyle superior

The most superior point of the condylar head

Superior-most point

First point that appears

Superior-most point

 

CdLR and CdLL

Condyle lateral pole

The most lateral point of the condylar head

First point that appears

Lateral-most point of the widest section of the condyle

Lateral-most point

 

CdMR and CdML

Condyle medial pole

The most medial point of the condylar head

First point that appears

Medial-most point of the widest section of the condyle

Medial-most point

 

CdAR and CdAL

Condyle anterior

The most anterior point of the condylar head

Anterior-most point

Middle-most point on the anterior surface of the widest section of the condyle

Medial-most point

 

CdPR and CdAL

Condyle posterior

The most posterior point of the condylar head

Posterior-most point

Middle-most point on the posterior surface of the widest section of the condyle

N/A

Temporal bone

GlSR and GlSL

Glenoid fossa superior

The most superior point of the glenoid fossa of the temporal bone

Superior-most point

First point that appears

Superior-most point

 

GlAR and GlAL

Glenoid fossa Anterior

The most inferior point of the articular eminence of the temporal bone

Inferior-most point on the articular eminence

Anterior-most point

Superior-most point

 

PoR and PoL

Porion

The most superior point of the external acoustic meatus

Superior-most point of the external acoustic meatus

First point that appears

Superior-most point of the external acoustic meatus

Reference planes

Axial plane

A plane that connects the most superior point of the external acoustic meatus with the most inferior point of the infraorbital rim on the right and left sides

Sagittal plane

A plane constructed using paired midfacial anatomic structures (eg., the orbits, frontal process of the maxilla, frontozygomatic suture)

Coronal plane

A plane constructed from the transporionic line