Sales Training 2014 - Dentistry

112

Oral Anatomy

the pumping action of the muscle every time the mouth opens. Spread of infection from the pterygoid plexus to the cavernous sinus is pos- sible, which can result in potential life-threaten- ing complications. 16. Kiesselbach’s area / Kiesselbach’s triangle: Also called Little’s area , it is a region in the anteroin- ferior part of the nasal septum which is highly

vascular. It is a site where five arteries, namely the anterior ethmoidal artery, the greater pala- tine artery, the sphenopalatine artery, the supe- rior labial artery and the lateral nasal branch of the facial artery, anastomose to form a vascular network called the Kiesselbach’s plexus. This is a frequent site of nasal bleeding/epistaxis (Fig. 5.15).

SECTION I

Frontal sinus

Posterior ethmoidal artery

Frontal bone Anterior ethmoidal artery

Sphenoidal sinus Septal branch of sphenopalatine artery

Kiesselbach’s plexus

Septal branch of superior labial artery Hard palate

Nasal septum

Soft palate

Greater palatine artery

Figure 5.15 Little’s area.

KEY POINTS

(a) Anterior division : Unites with facial vein to form the common facial vein (b) Posterior division : Unites with the posterior au- ricular vein to form the external jugular vein 6. Muscles of the eyeball are supplied by the ophthal- mic artery (branch of the cerebral part of the internal carotid artery). 7. Arterial supply of the tongue is by the lingual artery (branch of the external carotid artery) and venous drainage is through the deep lingual vein. 8. The maxillary artery is divided into three parts— mandibular, pterygoid and pterygopalatine—on the basis of its relation to the lateral pterygoid muscle. 9. The maxillary artery is a branch of the external ca- rotid artery. It supplies the upper and lower jaws, muscles of mastication, nose and paranasal sinuses and the palate. (a) Upper jaw and teeth: Posterior superior alveolar artery (i) Infraorbital artery (ii) Palatine artery (b) Lower jaw and teeth: Inferior alveolar artery

1. Arterial supply to the face is mainly by two arteries that are branches of the external carotid artery: (a) Facial artery: Branch of external carotid artery (b) Transverse facial artery: Branch of superficial temporal artery 2. Some areas of the face are supplied by the branches of the internal carotid artery: (a) Orbital structures: Ophthalmic artery (b) Skin of forehead: Supratrochlear and supraorbital branches (c) Eyelids: Medial palpebral branch (d) Upper part of nose: Dorsal nasal branch 3. Venous drainage of the face is by the common facial vein. 4. The upper lip and lower part of the nose constitute the danger area of the face. This is because the facial vein which drains these regions is connected to the cavernous sinus present in the cranium through the deep facial vein and pterygoid plexus. Infection can spread from the danger area to the cranium. 5. The retromandibular vein is formed by the union of the superficial temporal and maxillary veins. It splits into two divisions—anterior and posterior.

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