MUSCLES 25 



The pterygo-maxillary ligament extends from the hamular 

 process to the posterior edge of the mylo-hyoid ridge of 

 inferior maxilla. It separates buccinator from superior con- 

 strictor of pharynx, giving origin to both. 



Risorius : fascia covering masseter(F) apex of depressor 

 anguli oris(F) (Facial). [Draws angle of mouth back.] (This 

 muscle is part of the platysma of neck.) 



TEMPORO-MAXILLARY REGION. 



Masseter : Superficial part. Malar process of superior maxilla. 

 Anterior of lower border of zygoma(TA) angle and lower 

 of outer surface of ramus(p). Deep part. Posterior lower 

 border and inner surface of zygoma (F) upper of ramus 

 and outer surface of coronoid process(p) (Inferior maxillary). 

 [Muscle of mastication; elevates lower jaw and draws it 

 forward.] 



The masseteric fascia, a continuation of the deep cervical 

 fascia, is attached above to the zygoma; continuing back- 

 wards it invests parotid gland (parotid fascia), from the deep 

 surface of which the stylo-maxillary ligament proceeds. 



Temporal: temporal fascia and fossa(F) internal surface 

 and fore part of coronoid process of inferior maxilla as far as 

 last molar(AT) (Inferior maxillary). [Muscle of mastication, 

 closing mouth ; anterior fibres protrude jaw, posterior retract.] 



The temporal fascia is attached above to the temporal ridge, 

 and divides below into two layers, which are attached to 

 inner and outer edges of superior border of zygoma. It 

 covers the temporal muscle, and between the two layers are 

 the temporal branch of temporo-malar nerve, and the orbital 

 branch of superficial temporal artery. 



PTERYGO-MAXILLARY REGION. 



External pterygoid : pterygoid ridge and surface below on 

 great wing of sphenoid, outer surface of external pterygoid 

 plate(r) pterygoid depression in front of neck of inferior 

 maxilla and inter-articular fibro-cartilage of temporo-maxillary 

 joint(p) (Inferior maxillary). [Muscle of mastication ; both 

 acting together protrude lower jaw : acting alternately cause 

 grinding movements, each moving jaw to opposite side.] 



Between sphenoidal and pterygoid attachments, the internal 

 maxillary artery dips down to reach spheno-maxillary fossa, and 

 the buccal and anterior deep temporal nerves appear. 



Internal pterygoid : inner surface of external pterygoid 

 plate, tuberosity of palate bone, and tuberosity of superior 



