BUCCINATOR PTERYGOIDEI. 133 



the temporal ridge on the side of the skull, extending from the external 

 angular process of the frontal bone to the mastoid portion of the temporal ; 

 inferiorly, it is connected to the upper border of the zygoma. The muscle 

 arises by tendinous fibres from the whole length of the temporal ridge, 

 and by muscular fibres from the temporal fascia and entire surface of the 

 temporal fossa. Its fibres converge to a strong and narrow tendon, which 

 is inserted into the apex of the coronoid process, and for some way down 

 upon its inner surface. 



Relations. By its external surface with the temporal fascia, which se- 

 parates it from the attollens and attrahens aurem muscle, the temporal 

 vessels and nerves ; and with the zygoma and masseter. By its internal 

 surface with the bones forming the temporal fossa, the external pterygoid 

 muscle, a part of the buccinator, and the internal maxillary artery with its 

 deep temporal branches. 



By sawing through the coronoid process near to its base, and pulling it 

 upwards, together with the temporal muscle, which may be dissected from 

 the fossa, we obtain a view of the entire extent of the buccinator and of 

 the external pterygoid muscle. 



The BUCCINATOR (buccina, a trumpet), the trumpeter's muscle, arises 

 from the alveolar process of the superior maxillary and from the external 

 oblique line of the inferior maxillary bone, as far forward as the second 

 bicuspid tooth, and from the pterygo-maxillary ligament. This ligament 

 is the raphe of union between the buccinator and superior constrictor 

 muscle, and is attached by one extremity to the hamular process of the 

 internal pterygoid plate, and by the other to the extremity of the molar 

 ridge. The fibres of the muscle converge towards the angle of the mouth 

 where they cross each other, the superior being continuous with the infe- 

 rior segment of the orbicularis oris, and the inferior with the superior 

 segment. The muscle is invested externally by a thin fascia. 



Relations. By its external surface, posteriorly with a large and rounded 

 mass of fat, which separates the muscle from the ramus of the lower jaw, 

 the temporal, and the masseter ; anteriorly with the risorius Santorini, the 

 zygomatici, the levator anguli oris, and the depressor anguli oris. It is 

 also in relation with a part of Stenon's duct, which pierces it opposite the 

 second molar tooth of the upper jaw, with the transverse facial artery, the 

 branches of the facial and buccal nerve, and the facial artery and vein. 

 By its internal surface with the buccal glands and mucous membrane of 

 the mouth. 



The EXTERNAL PTERYGOID is a short and thick muscle, broader at its 

 origin than at its insertion. It arises by two heads, one from the pterygoid 

 ridge on the greater ala of the sphenoid; the other from the external 

 pterygoid plate and tuberosity of the palate bone. The fibres pass back- 

 wards, to be inserted into the neck of the lower jaw and the interarticular 

 fibro-cartilage. The internal maxillary artery frequently passes between 

 the two heads of this muscle. 



Relations. By its external surface, with the ramus of the lower jaw, 

 the temporal muscle, and the internal maxillary artery ; by its internal 

 surface, with the internal pterygoid muscle, internal lateral ligament of the 

 lower jaw, arteria meningea media, and inferior maxillary nerve ; and by 

 its upper border, with the muscular branches of the inferior maxillary 

 nerve ; the internal maxillary artery passes between the two heads of this 

 muscle, ani its lower origin /s pierced by the buccal nerve 



