Blood and Nerve Supply of Bone Question And Answers

Dento-Osseous Structures, Blood Vessels, And Nerves

Question 1. Describe the blood and nerve supply of maxillary teeth.
Answer:

Blood supply:

• The maxillary teeth are supplied by the maxillary artery, a branch of the external carotid artery.
• The maxillary artery gives off superior alveolar and inferior alveolar arteries.
• Out of it inferior alveolar artery and its branches supply mandibular teeth.

Read And Learn More: BDS Previous Examination Question And Answers

Superior alveolar artery:

1. Posterior superior alveolar artery:

• It runs superior to the maxillary tuberosity and enters the alveolar canals.
• It supplies maxillary teeth, alveolar bone, and the membrane of the sinus.
• Then it travels forward and supplies the gingiva, alveolar mucosa, and cheek.

2. Middle superior alveolar artery:

• It runs to join posterior and anterior alveolar vessels.
• It supplies maxillary premolar teeth.

3. Anterior superior alveolar artery:

• It runs towards the anterior aspect of the maxilla from the infraorbital foramen and supplies maxillary anterior teeth and their supporting tissues.

4. Dental branches:

• It enters into individual tooth root canals and supply of the pulp and periodontal membrane at the root apex.
• Other branches enter the interdental septa and supply bone and adjacent periodontal ligament and gingiva.

Palatal aspect:

1. Sphenopalatine artery:

• Its nasopalatine branch enters the palate through the incisive canal and supplies the anterior palate.

2. Greater palatine artery:

• It enters the palate through the greater palatine foramen.
• It is distributed to the bone, glands, and mucosa of the hard palate.

3. Descending palatine artery:

• Its minor branches pass to the soft palate through the lesser palatine foramina.

Nerve supply:

1. Posterior superior alveolar nerve:

• Branch of the maxillary nerve.
• It enters the alveolar canals, forms the plexus, and supplies molar teeth and supporting tissues.

2. Infraorbital nerve:

• It is a branch of the maxillary nerve.
• It gives off the middle superior alveolar branch supplying premolar teeth and surrounding tissues.

3. Anterior superior alveolar nerve:

• It passes through the bony canals and supplies incisor and canine teeth.

4. Dental branches:

• All three superior alveolar nerves form plexus out of which dental branches are given.
• These along with interdental branches supply alveolar bone, periodontal ligament, and gingiva.

5. Greater palatine branch:

• Enters the hard palate through the greater palatine foramen.
• It supplies the hard palate and palatal gingiva up to the canine tooth.

6. Lesser palatine branch:

• Enters the soft palate through the lesser palatine foramen.

7. Nasopalatine branch:

• Enters the palate through the incisive canal.
• It is distributed to the incisive papilla.

Question 2. Write briefly about the lingual nerve.
Answer:

Lingual nerve:

• It is a branch of the posterior division of the mandibular nerve.

Course:

• It begins 1 cm below the skull.
• Below this, point, it joints chorda tympani nerve.
• Next, it contacts the mandible medial to 3rd molar.
• Finally lies on the surface of hyoglossus and genioglossus and reaches the tongue.

Relations:

• During its course, the lingual nerve is related to various structures.
• They are
  • Muscles – lateral and medial pterygoid, tensor veli palatine, mylohyoid, hyoglossus, genioglossus, a superior constrictor.
  • Nerve – chord company.
  • Bone – ramus of mandible
  • Teeth-3rd molar
  • Others submandibular duct, and tongue.

Structures supplied by it:

Structures:

• Sensory – Anterior two-thirds of the tongue, Floor of the mouth
• Secretomolor – Submandibular and sublingual glands
• Gustatory – Anterior two-thirds of the tongue.

Question 3. Ramus of the mandible.
Answer:

• It is quadrilateral in shape.
• It has:
  • 2 surfaces – lateral and medial
  • 4 borders upper, lower, anterior, and posterior.
  • Coronoid, condylar processes.
• Lateral surface
  • Consists of oblique ridges.
• Medial surface: consists of.
  • Mandibular foramen containing mandibular canal and marked by lingula.
  • Mylohyoid groove – below mandibular foramen.
• Upper broader – forms mandibular notch.
• The lower border continues as the base of the mandible.
• Anterior border – it is thin
• Posterior border – it is thick

Coronoid process:

• It is a pointed, flattened, smooth projection.

Condyloid process:

• It appears as a rounded knob.
• It is articulated to the skull and forms a temporomandibular joint.

Muscles attached:

• Masseter to the lateral surface.
• Sphenomandibular ligament – to lingula.
• Medial pterygoid muscle on the medial surface.
• Temporalis – to the apex and medial surface of the coronoid process.

Question 4. Inferior alveolar nerve.
Answer:

• It is a terminal branch of the posterior division of the mandibular nerve.

Course:

• It runs downwards across the medial/surface of the lateral pterygoid.
• Next, it crosses the outer surface of the medial pterygoid muscle to reach the mandibular foramen.
• Just before entering the foramen, it releases the mylohyoid branch.

Branches:

• The mylohyoid branch supplies the mylohyoid muscle and the anterior belly of the digastric.
• Interdental branches – supply lower teeth, alveolar bone, periodontal membrane, and gingiva.
• Mental branch – supplies the skin of the chin, the skin, and the mucous membrane of the lower lip.
• Incisive branch supplies the labial aspect of the gingiva of canine and incisor teeth.

Question 5. Mandibular nerve
Answer:

Origin:

• Originates in the middle cranial fossa through its roots

Root fibers:

• It has two roots
• Sensory root-large root
• Motor root-small root

Branches:

1. From the main trunk

• Meningeal branch
• Nerve to medial pterygoid

2. From the anterior trunk

• Buccal nerve
• Masseteric nerve
• Deep temporal nerve
• Nerve to lateral pterygoid

3. From the posterior trunk

• Auriculotemporal nerve
• Lingual nerve
• Inferior alveolar nerve

Termination:

• It terminates by dividing into a small anterior trunk and a large posterior trunk

Question 6. Pain
Answer:

Definition:

• It is defined as an unpleasant and emotional experience associated with or without actual tissue damage.

Advantages:

• Creates awareness of injury
• Produces reflex withdrawal response
• Forces people to rest or minimize their activities
• Urges person to take required treatment

Components:

1. Fast pain

• Bright, sharp, and localized pain sensation

2. Slow pain

• Dull, diffused, and unpleasant pain

Types:

1. Superficial pain – involves the skin and subcutaneous tissue
2. Deep pain involves muscle and hollow viscera

Question 7. Tuberosity.
Answer:

• It is a rounded eminence seen posterior inferior to the infratemporal surface of the maxilla.
• It overhangs the root of the third molar.
• It is bounded by a sharp, irregular margin.
• It articulates with the pyramidal process of the palatine bone.
• It gives origin to the superficial head of the medial pterygoid muscle.
• Superior to the maxillary tuberosity is the anterior boundary to the pterygomaxillary fissure.

Question 8. Genial tubercle.
Answer:

• It can be seen over the internal surface of the mandible.
• The median line of the mandible is marked by a slight vertical depression.
• Immediately below it, the bone is roughened by eminences called genial tubercles.
• These are four small elevations, superior, and inferior genial tubercles.

Attachment:

• Upper genital tubercle- gives origin to the genioglossus, muscle.
• Lower genital tubercle – gives origin to the geniohyoid muscle.

Question 9. Mental foramen.
Answer:

• It is the opening of the anterior end of the mandibular canal.

Location:

• Midway between the superior and inferior border of the body of the mandible.
• Below premolar root apex.
• Or between 1st and 2nd premolar.
• Near the crest of the alveolar border – after bone resorption.
• Below first primary molar – in the child’s mandible.

Structures passing through it:

• Mental nerve and vessels.

Question 10. Nerve supply of the palate.
Answer:

1. Greater palatine branch of the maxillary nerve.

• Enters the hard palate through the greater palatine foramen.
• It supplies a hard palate.

2. Lesser palatine branch from the ganglion.

• Enters the soft palate through the lesser palatine foramen.

3. Nasopalatine branch of the superior lateral nasal branch.

• Enters the palate through the incisive canal.
• Supplies incisive papilla and to the palate anterior to the greater palatine nerve.

Question 11. Lymphatic drainage of maxillary teeth.
Answer:

• Maxillary incisors – submental lymph nodes.
• Remaining maxillary teeth – submandibular lymph nodes.

Question 12. Blood supply of mandibular teeth.
Answer:

• All mandibular teeth are supplied by the inferior alveolar artery and its branches.

Anterior:

• Supplied by incisive branch.
• Labial supporting tissues are supplied by the mental branch and lingual supporting tissues by the lingual artery.

Posteriors:

• Premolar and molars are supplied by the inferior alveolar artery.
• This gives off branches to the premolar and molar through the mandibular canal.

Dental branches:

• These branches are given to the individual tooth roots to supply pulp and periodontal membrane at the root apex.

Question 13. Greater palatine foramen.
Answer:

Location:

• One on each side
• It is situated just behind the lateral part of the palatomaxillary suture.

Structure passing through it:

• Greater palatine vessels.
• Anterior palatine nerve.

Question 14. Canine fossa.
Answer:

Location:

• Posterior to the canine eminence.

Boundaries:

• Floor – formed by the zygomatic process
• The major portion is directly above premolar roots.

Relations:

• Infra orbital foramen – above canine fossa.
• The canine fossa gives origin to levator anguli oris.

Question 15. Mylohyoid ridge.
Answer:

• It is a prominent ridge running from below the third molar tooth to the median area below the genial tubercle.
• It gives origin to the mylohyoid muscle.
• Above the mylohyoid ridge – there is a sublingual fossa containing a sublingual gland.
• Below the mylohyoid ridge is the submandibular fossa lodging the submandibular gland.

Question 16. Fossae are present in the mandible.
Answer:

Question 17. Foramina of mandible.
Answer:

1. Mental foramen.

• Its position varies.

1. May be located between the superior and inferior border of the body of the mandible when teeth are in position.
2. May be below the second premolar tooth or
3. May be between the first and second premolar tooth.
4. After bone resorption in old age, it appears near crest of the alveolar border.
5. Before the eruption of a first permanent molar, it is present below the first primary molar.
6. Structures transmitted through it are mental nerves and vessels.

2. Mandibular foramen.

• Located between the mandibular notch and the angle of the mandible.
• Its anterior margin is formed by lingual.
• The inferior alveolar nerve passes through it.

Question 18. Mental nerve
Answer:

Question 19. Inferior alveolar nerve
Answer:

The inferior alveolar nerve is the main nerve for mandibular teeth It is the largest branch of the mandibular nerve.

Branches:

Question 20. Nerve supply to mandibular teeth
Answer:

• Incisive branch – remain within the canal
• Mental branch – exit the canal through the mental foramen