Mandible : important viva questions and answers

 

Mandible

1.    Anatomical points

·       Horse-shoe shaped , convex body is directed forward

·       Inferior border lies horizontally

·       Rami of manbible are directed upward

2.    Morphological type: flat bone  

3.    Ossification: both intra membranous and intra cartilaginous

·       Part of ramus behind the opening of mandibular foramen is ossify from the cartilage

·       rest of the mandible is ossify from the membrane

4.    Development: neural crest

5.    Parts: body, ramus

Body:

·       Two surfaces: external and internal

·       Two borders: superior and inferior border

External surface of body of mandible:

Identify following points: 

symphysis menti

Mental protuberance

Mental tubercle

Mental foramen

External oblique line

Incisive fossa

Internal surface of body of mandible

Mylohyoid line and mylohyoid groove

Mandibular foramen and lingual

Groove for lingual nerve

Submandibular and sublingual fossa

Two upper and two lower genial tubercles

Lower border of body of mandible:

Thick and  rounded lower border of body of mandible continuous with lower border of ramus

Two Digastrics fosse are situated near the median plane

Origin of anterior belly of digastrics are attached here

Whole inferior border is attached with platysma and investing layer of deep cervical fascia

Superior border(alveolar part )  of body of mandible

It bears 16 sockes, 8 on each side  which lodge the roots of teeth

1.    Medial or 1^st incisor (I)

2.   Lateral or 2^nd incisor

3.   Canine (C)

4.   1^st premolar (P)

5.   2^nd premolar

6.   1^st molar (M)

7.   2^nd molar

8.   3^rd or last molar

Dental formula: IPCM/2123

Ramus of mandible:

Two surfaces:

Lateral surface: insertion of masseter muscle

Upper and posterior part is related with parotid gland

and medial surface :

Insertion of medial pterygoid muscle: below and behind the medial surface of mandible

mandibular foramen: transmit inferior alveolar nerve branch of mandibular nerve and inferior alveolar vessels

lingual: a sharp thin process of mandibular foraman it is attached with sphenomandibular ligament

myolohyoid groove contain myolohyoid nerve and vessels

 

4 borders :

Anterior

Posterior

Upper

Lower

Two processes

1.    Coronoid

2.   Condyloid

 

6.   Show the bony attachment of following muscles

·       Muscles of mastication:  Show their  attachment with their nerve supply

·       Buccinator, myolohyid, geniohyoid and genioglossus, anterior belly of digastrics muscle, platysma etc.

7.   Relation:

Relation of salivary glands: show the location of following gland on the bone and mention their types and nerve supply

·       Parotid gland

·       Submandibular gland

·       Sublingual gland

Relation of Nerves : show the location on the bone

·       Auriculotemporal nerve

·       Messeteric nerve

·       Marginal mandibular nerve of facial nerve

·       Lingual nerve

·       Myolohyoid nerve

8.    Foramen and structures passing through it:  

·       mandibular formamen,

·       mental foramen

9.   Joints:

1.     Temparomandibular joint (mention their type, articular surfaces, movement, peculiarity )  

2.    Dentoalveolar joint(type) ,

3.    Symphysis menti (type)