C Stylohyoid bone
D Epihyoid bone
E Ceratohyoid bone
F Basihyoid bone
G Thyrohyoid bone
1 Incisive bone
2 Nasal bone
3 Frontal bone
4 Parietal bone
5 Osseous tentorium of the cerebellum
6 Interparietal bone
7 Occipital bone
7(a) External occipital protuberance or ‘nuchal crest’
8 Occipital condyle
9 Jugular process of occipital bone
10 Petrous temporal bone or temporal bone-petrosal part
11 Tympanic bulla of temporal bone or temporal bone-tympanic part
12 External acoustic meatus of temporal bone
13 Zygomatic process of temporal bone or temporal bone-squamous part
14 Retroarticular process of temporal bone
15 Mandibular fossa of temporal bone
16 Palatine process of maxilla. The vomer lies dorsally.
17 Palatine bone. Rostrally the palatine process of maxilla is included.
18 Sphenoid sinus of presphenoid
19 Cribriform plate of ethmoid bone. Rostral limit only is visible.
20 Ethmoidal fossa
21 Ethmoidal conchae
22 Dorsal nasal conchae
22(a) Dorsal nasal meatus
23 Middle nasal conchae
23(a) Mass of conchae attached to the ethmoid bone, from the dorsal and middle conchae. Seen as a radiopaque region and must not be mistaken for a foreign body.
24 Ventral nasal conchae
24(a) Ventral nasal meatus
25 Dorsal orbital margin
26 Basisphenoid bone
27 Frontal sinuses
28 Mandibular body
29 Mandibular ramus
30 Coronoid process of mandible
31 Condyloid or articular process of mandible
32 Angular process of mandible
33 Mandibular foramina
34 Mandibular canal
35 Mental foramen
36 Lamina dura
37 Soft palate
1 Upper incisors. Total of six.
2 Lower incisors. Total of six.
3 Upper canines. Total of two.
4 Lower canines. Total of two.
5 Upper premolars. Total of six.
6 Lower premolars. Total of four.
7 Upper molars. Total of two.
8 Lower molars. Total of two.
Note that the term ‘upper’ can be replaced by ‘superior’ and ‘lower’ by ‘inferior’.
C Cartilaginous ear canal
1 Incisive bone
2 Maxilla or maxillary bone
2(a) Maxillary teeth obscuring bony shadows of maxillary bone (lamina dura seen as radiopaque lines)
3 Vomer and nasal septum (the osseous part of the nasal septum contributes to the radiopaque line)
4 Temporal process of zygomatic bone
5 Frontal process of zygomatic bone
6 Zygomatic process of frontal bone
7 Zygomatic process of temporal bone. Forms zygomatic arch with (4).
8 Frontal sinuses
9 Sphenoidal sinuses
10 Cribriform plate of ethmoid enclosing ethmoidal fossa
11 Ethmoturbinates and dorsal nasal concha (dorsal nasal concha is not seen clearly on this projection)
12 Border of choanae formed by palatine bone
13 Medial wall of orbit
14 Ventral margin of orbit
15 Lamina dura
15(a) Mandibular lamina dura
15(b) Maxillary lamina dura
16 Mandibular body
17 Coronoid process of mandibular ramus
18 Angular process of mandibular ramus
19 Condyloid or articular process of mandibular ramus
20 Retroarticular process of temporal bone
21 Tympanic bulla of temporal bone
22 External acoustic meatus of temporal bone
23 Internal acoustic meatus of temporal bone
24 Jugular foramen
25 Petrous temporal bone
26 Mastoid process of petrous temporal bone
27 Occipital condyle
28 Nuchal crest
29 Hamulus of pterygoid bone
30 Osseous tentorium of cerebellum
31 Foramen magnum
1 Lower incisors. Total of six.
2 Upper incisors. Total of six.
3 Lower canines. Total of two.
4 Upper canines. Total of two.
5 Lower premolars. Total of four.
6 Upper premolars. (The 1st premolar in this cat appears to be present, making a total of eight instead of six. This is unusual.)
7 Lower molars. Total of two.
8 Upper molars. Total of two.
Note that the term ‘lower’ can be replaced by ‘inferior’ and the term ‘upper’ by ‘superior’.
A Temporomandibular joint of recumbent side
B Temporomandibular joint of non-recumbent side
1 Body of mandible
2 Angular process of mandible
3 Condyloid or articular process of mandible
4 Coronoid process of mandible
5 Mandibular fossa of temporal bone
6 Retroarticular process of temporal bone
7 Tympanic bulla of temporal bone
8 External acoustic meatus of temporal bone
9 Cribriform plate
10 Petrous temporal bone
11 Cranial base
12 Occipital condyle
14 Stylohyoid bone
15 Epihyoid bone
16 Ceratohyoid bone
17 Basihyoid bone
18 Thyrohyoid bone
19 Soft palate
21 Rostral limit of arytenoid cartilage