Skull Morphology,Topography, and Landmarks

Mesocephalic skull

Typical head shape

Mesocephalic skull

Petrous pyramids 47 degrees from MSP

Brachycephalic skull

Short from front to back

Brachycephalic skull

Petrous pyramids 54 degrees from MSP

Dolichocephalic skull

Long from front to back

Dolichocephalic skull

Petrous pyramids 40 degrees from MSP

Infraorbitomeatal Line (IOML)

Other term: Reid's base line

Infraorbitomeatal Line (IOML)

Other term: Line of Frankfurt

Infraorbitomeatal Line (IOML)

Other term: Anthropological base line

Infraorbitomeatal Line (IOML)

Other term: Base line of the cranium

Infraorbitomeatal Line (IOML)

Line which connects the infra-orbital point to the EAM

OML and GML (Glabellomeatal Line)

Approximate 8° average angle difference

OML and IOML

Average difference of 7° exists

IOML and AML (Acanthiomeatal Line)

Average difference of 15° exists

IOML and GML

Average difference of approximately 15° exists

Glabelloalveolar line

Extends from the glabella to the anterior alveolar process of the maxilla

Orbitomeatal line (OML)

Extends from the outer canthus of the eye to the external auditory meatus (EAM)

Infraorbitomeatal line (IOML)

Extends from the infraorbital margin to the EAM

Acanthiomeatal line (AML)

Extends from the acanthion to the EAM

Mentomeatal line (MML)

Extends from the mental point, or chin, to the EAM

Glabellomeatal line (GML)

Extends from the glabella to the EAM