Recapitulación de los rasgos aspectuales de ya

It extends from the lips to the junction of hard and soft palate and circumvallate papillae (Figs 1 and 2). The subsites of oral cavity categorized by the American Joint Committee on Cancer Staging (AJCC) are shown in Box 1.

„ _{Hard palate is included in the oral cavity whereas soft palate}

is the part of oropharynx. The anterior two-third of tongue is the part of oral cavity while the posterior one-third of tongue is included in oropharynx.

lips

Lips form the anterior boundary of the oral cavity.

„ _{Parts: The two surfaces of lip, skin and mucosal, become}

continuous with one another round its red margin, which is called vermilion.

„ _{Vermilion border: The site along which the two lips meet with}

one another is marked by a line that indicates transition from a dry vermilion to a moist vermilion.

 The dry vermilion with a pattern of wrinkles has clear cut

boundary line between it and the skin proper, patterned with Cupid’s bow in upper lip and central fullness in the lower lip.

 The smooth wet vermilion merges without obvious

surface change with mucosa lining of lip. Mucosal surface has mucous glands and supporting tissue within the muscle and mucosa.

„ _{Epithelium: The lip is covered with non-keratinized stratified}

squamous epithelium which is transparent and contains no hairs, sebaceous glands, or pigments. Therefore it appears red. On the vermilion border the mucosa is closely applied to the orbicularis muscle and the distance between the epithelium and muscle is just 2 mm.

Fig. 1: Sagittal section head showing subsites of oral

cavity and oropharynx

Fig. 2: Oral cavity overview

• An ulcerative squamous cell carcinoma lesion fixes the skin early to the deep substance of lip because of the 2 mm distance between the epithelium and muscle.

• Commissure of mouth: As far as possible, it should be spared during the surgery because it is very delicate and difficult to reconstruct.

„ _{Blood supply: Small submental arteries and inferior and}

superior labial arteries which are branches of facial artery supply to lips.

„ _{Lymphatic drainage:}

 Lower lip: Medial portion of lower lip drains into

submental (level I) and lateral portion to submandibular nodes (level I).

 Upper lip: It drains into preauricular, infraparotid and

submandibular nodes.

alveoli and Gingivae

Gums (gingivae) surround the teeth and cover the upper and lower alveolar ridges.

„ _{Lymphatic drainage:}

 _{Upper alveolus:}

– _{Buccal aspect of mucosa drains to submandibular}

nodes.

– _{Lingual aspect drains either directly to upper deep}

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Chapter 3

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a

natomy and Physiology of Oral Cavity

, Pharynx, and

e

sophagus

 Lower alveolus: The central part of both buccal and

lingual surfaces of mucosa drains to submental whereas lateral parts drain to submandibular nodes.

Floor of Mouth (Fig. 3)

Floor of mouth is a crescent-shaped area that lies between the gingivae and undersurface of tongue. There are few minor salivary glands in the floor of mouth.

„ _Examination:

– _{Anterior portion of the floor (frenulum, sublingual}

papillae with openings of submandibular ducts) is examined when patient raises the tip of tongue towards the hard palate.

– _{Lateral portion of the U-shaped floor of mouth is}

examined by displacing the tongue in medial direc- tion with the help of a tongue depressor.

„ _{Lymphatic Drainage:}

– _{Anterior portion of floor of mouth drains into}

submental and submandibular nodes (level I). Lymphatics from this area also cross the midline.

– _{Posterior portion drains into upper deep cervical}

nodes (level II and III).

Buccal Mucosa

It is covered with non-keratinizing stratified squamous epithe- lium. Buccal mucosa lines the inner surface of cheeks and lips and extends between the superior and inferior gingivobuccal sulcus. It extends posteriorly up to pterygomandibular raphe and anteriorly to the meeting line of lips. It covers parotid duct, minor salivary glands, buccinator muscle and upper and lower alveoli.

„ _{Lymphatic Drainage: Buccal mucosa drains into submental}

and submandibular nodes and from there to the deep cervical lymph nodes.

Carcinoma of buccal mucosa is the second most common cancer of oral cavity after the tongue.

Retromolar trigone

Retromolar trigone is a triangular area of mucosa that covers anterior border of the ascending ramus of mandible. It lies behind the third molar, where the pterygomandibular raphe is attached to the mandible. Its base lies posterior to the last molar while its apex is adjacent to the maxillary tuberosity. The pterygomandibular raphe provides origin to superior constrictor and buccinator muscles.

hard Palate

Hard palate forms the roof of the oral cavity and floor of the nasal cavity. It contains high number of minor salivary glands.

in hard palate, minor salivary glands tumors such as adenoid cystic, mucoepidermoid and adenocarcinoma are more common than squamous cell carcinoma. most of the squamous cell carcinoma of upper alveolus and hard palate arises from maxillary antrum.

„ _{Lymphatic drainage:}

– _{Anterior part of palate drains to submandibular}

nodes.

– _{Posterior part drains either directly to the upper deep}

cervical or via lateral retropharyngeal nodes.

tongue

Anterior two-third of tongue is the content of the oral cavity (Fig. 4). Posterior one-third (base of tongue) is situated behind the circumvallate papillae and forms anterior wall oropharynx.

„ _{Parts: Oral tongue can be divided into the tip, lateral borders}

and dorsum and ventral surfaces of the tongue.

• The interlacing tongue muscle fibers and constant movement of tongue (speech and chewing) facilitate spread and wide dissemination of tongue cancer.

• the palpation of tongue tumors and excision of cancer lesion with 2 cm safe margin are of paramount importance.

Box 1: Subsites of cancer in oral cavity 1. lip (vermilion surface)

a. Upper lip b. Lower lip c. Commissures

2. Buccal mucosa (includes mucosa of cheek and inner surface of lips up to line of contact of opposing lip): Mucosal surfaces of

a. Upper and lower lips b. Cheeks

c. Retromolar area

d. Upper and lower buccoalveolar sulci

3. anterior two-third of tongue (anterior to circumvallate papillae)

a. Dorsal and ventral surfaces b. Lateral borders

c. tip

4. hard palate

5. lower alveolar ridge (alveolus and gingiva) 6. upper alveolar ridge (alveolus and gingiva) 7. Floor of mouth

8. Retromolar trigone

Source: AJCC 1997

Section 1

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Basic Sciences

„ _{Lymphatic Drainage:}

 Tip of tongue drains to submental and deep jugular

cervical chain.

 Sublingual surface drains to the submandibular nodes.  The rest of the anterior two-third of tongue drains to the

deep jugular chain of lymph nodes. These level III nodes are situated between digastric and omohyoid muscles.

 Central portion and base drain into deep cervical nodes

of both sides.

Lymphatics from anterior portion of mouth can sometimes drain directly to lower jugular chain (levels III and IV).

the patients with cancer of lateral border of anterior two-third can have enlargement only of jugulodigastric and jugulomohyoid lymph nodes.

Pre-Facial and Post-Facial lymph nodes

These lymph nodes are present near the anteroinferior angle of masseter muscle where facial artery crosses the inferior margin