The cranial end of the bone articulates with the premaxilla.
The caudal end is smooth.
The frontal process (b) presents on its inner surface, which looks into the nasal cavity, certain transverse ridges which are in relation with the ethmoid bone. Its outer surface is smooth. By its cranial border it articulates with the nasal bone dorsally and with the premaxillary bone ventrally.
Fig. 29.—Premaxillary Bone, Obliquely Craniolateral Aspect.
a, the three incisor teeth; b, palatal portion of the bone; c, nasal process.
Its dorsal end articulates medially with the nasal spine of the frontal bone, and caudally with the orbital plate of the same bone.
Premaxillary Bone. (Os incisivum BNA.) Premaxilla
([Fig. 29]).—The premaxillary bones bear the incisor teeth and form the cranial portion of the roof of the mouth.
Each consists of an irregular, horizontal palatal portion (b) and of a perpendicular nasal process (c) which forms part of the lateral boundary of the nares and enters into the formation of the lateral wall of the nasal cavity.