Measuring sections on the skull
Measuring sections on the skull or skull dimensions are used in craniometry to measure the length of sections on the skull of vertebrates . Some of them relate to fixed measuring points on the skull (indicated here in brackets) and can be removed with a calliper or caliper .
Skull lengths
Occipitonasal length
The occipitonasal length is the distance between the tangent to the front edges of the nasal bones and the rearmost point of the occiput above the large occipital opening . In rodents , the largest skull length usually coincides with the occipitonasal length.
Condylobasal length
The condylobasal length is the distance between the tangent to the rearmost points ( condylion ) of the occipital cusps and the tangent to the anterior margin ( gnathion ) of the intermaxillary bones . In rodents , measurements are taken up to the front edges of the first upper incisors , where they emerge from the intermaxillary bone, since the front edge of the intermaxillary bone is often damaged and is easily destroyed when measuring. The condylobasal length is one of the most common skull dimensions.
Condyloincisive length
The condyloincisive length is the distance between the tangent to the rearmost points (condylion) of the occipital cusps and the tangent to the foremost points of the first upper incisors. In orthodontic skulls, it roughly corresponds to the length of the condylobasal. The differences can serve as a measure of the degree of proodontics .
Condylobasilar length
The length of the condylobasilar is the distance between the tangent to the rearmost points (condylion) of the occipital cusps and the tangent to the rear edge ( Henselion ) of the tooth sockets of the first upper incisors.
Basal length
The basal length is the distance between the anterior point ( basion ) of the lower edge of the large occipital opening and the tangent to the anterior edge of the intermaxillary bones (gnathion).
Basilar length
The basilar length is the distance between the anterior point (basion) of the lower edge of the large occipital opening and the tangent to the posterior edge (henselion) of the sockets of the first upper incisors.
Palate lengths
Palatal length
The Palatallänge are as the length of the bony palate the distance between the tangent to the foremost points ( Palation ) of the rear edge of the palate legs and the tangent to the front edge (Gnathion) of the intermediate jaw legs.
Palatilar length
The Palatilarlänge are as length of the hard palate of the distance between the tangent to the foremost points (Palation) of the rear edge of the palate legs and the tangent to the trailing edge (Henselion) of the alveoli of the first upper incisors.
Further length dimensions
Nasal length
The Nasalialänge are as length of the nasal bone to the distance between the front and rear tangent to the nasal bones. Fine tooth peaks are not taken into account.
Length of the skull
The length of the facial skull is the distance between the front edge of the nasal bones and the translucent rear border of the sieve plate of the ethmoid bone.
Length of the skull
The length of the skull is the distance between the translucent posterior border of the sieve plate of the ethmoid bone and the furthest point of the supraoccipital of the occiput.
Length of the tympanic membranes
The length of the tympanic sac is the distance between the anterior and lowest point of contact between the tympanic bladder and the paroccipital process of the occiput and the anterior border of the tympanic bladder , which adjoins the posterior sphenoid bone . Massive bone processes are not taken into account.
Length of the incisor holes
The length of the incisor holes corresponds to the length of the longer incisor hole parallel to the skull axis.
Diastema length
The diastema length indicates the length of the toothless gap as the smallest distance between the edge of the tooth socket of the last incisor and the edge of the tooth socket of the first molar . It is not measured parallel to the skull axis.
Length of the molar rows
The length of the molar rows can be measured in three different ways:
- The distance between the foremost point of the socket of the first molar and the rearmost point of the socket of the last molar.
- The distance between the foremost point of the tooth crown of the first molar tooth and the rearmost point of the tooth crown of the last molar tooth.
- The distance between the foremost point of the edge of the chewing surface of the first molar and the rearmost point of the edge of the chewing surface of the last molar. This method of measurement is used in voles .
Mandible length
The Mandibellänge are as length of the lower jaw, the distance on the inside of the lower jaw between the front edge of the foremost tooth socket and the rear of the articular process of the mandible.
Width dimensions
Nasal width
The Nasaliabreite are as width of the nasal bones of the greatest distance between the edges of the nasal bones.
Rostral width
The rostral width indicates the width of the rostrum at the front edge of the incisor holes.
Interorbital width
The interorbital width is the smallest distance between the edges of the frontal bones in the area of the bony eye sockets . In the absence of postorbital processes, the interorbital width can also denote the smallest distance between the edges of the frontal bones behind the eyes and within the zygomatic arches.
Postorbital width
The postorbital width is the smallest distance between the edges of the frontal bones behind the postorbital processes .
Zygomatic width
The zygomatic width , zygomatic width or, incorrectly, the zygomatic arch width is the largest distance between the outer edges of the zygomatic arches .
Mastoid width
The mastoid width indicates the distance between the outer sides of the tympanic sacs behind the ear canal as the width of the skull .
Occipital width
The occipital width is the greatest distance between the outer edges of the occiput and is usually measured on the parietal ridges of the parietal bones.
Height measurements
Rostral height
The rostral height indicates the height of the rostrum above the front edge of the incisor holes .
Height of the skull
The height of the skull can be measured in different ways:
- The height of the skull without tympanic bubbles indicates the distance between the roof of the skull and the seam between the occiput and the anterior sphenoid bone .
- The height of the cerebral skull with tympanic sacs indicates the approximately vertical distance between the lower tangent to the tympanic sacs and the top of the skull. The orientation is not handled uniformly.