Dental Materials Miscellaneous Question And Answers

Dental Materials Miscellaneous

Question 1. Describe blood supply and lymphatic drainage of the tongue.
Answer:

Muscles of the tongue:

1. Intrinsic muscle:

1. Superior longitudinal:
   1. It lies beneath the mucous membrane.
   2. It shortens the tongue and makes it dorsum concave.
2. Inferior longitudinal:
   1. It is a narrow band lying close to the inferior surface of the tongue between the genioglossus and the hyoglossus.
   2. It shortens the tongue and makes its dorsum convex.
3. Transverse:
   1. It extends from the median septum to the margins.
   2. It makes the tongue narrow and elongated.
4. Vertical:
   1. It is found at the borders of the anterior part of the tongue.
   2. It makes the tongue broad and flattened.

Read And Learn More: BDS Previous Examination Question And Answers

2. Extrinsic muscle:

• Genioglossus – connects the tongue to the mandible
• Hyoglossus connects the tongue to the hyoid bone
• Styloglossus connects the tongue to the styloid process
• Palatoglossus – connects the tongue to the palate.

Arterial supply:

• Lingual artery – a branch of the external carotid artery
• Tonsillar branch of the facial artery
• Ascending pharyngeal branch of the external carotid.

Venous drainage:

• Deep lingual vein.
• This ends in the internal jugular vein.

Lymphatic drainage:

• Tip of the tongue – to submental nodes
• Anterior rd of the tongue – to submandibular nodes
• Posterior rd of the tongue – to jugular -omohyoid nodes
• Posterior most part – upper deep cervical lymph nodes.

Question 2. Functions of tooth 
Answer: 

1. Functions of tooth Chewing Food needs to be broken and chewed before entering the digestive system so that our body can easily absorb nutrients from them
2. Functions of Tooth Speech Teeth help to pronounce accurately
3. Functions of tooth Esthetic Teeth help to look good
4. Preserve space for permanent teeth Deciduous teeth provide room for permanent teeth

 

Question 3. Pain pathway
Answer:

Pain pathway for fast pain:

The remaining terminates in:

• Reticular formation of the brainstem
• Tectum of brainstem
• Grey matter around the aqueduct of Sylvius
• Terminating sites forms third order neuron

Question 4. Nerve supply to the tongue.
Answer:

1. Motor nerves:

• Palatoglossus muscle – by the cranial root of the vagus nerve
• All other muscles – hypoglossal nerve.

2. Sensory nerves:

• General sensation – lingual nerve.
• A taste sensation for anterior 2/3rd except vallate papillae chorda tympani.
• General sensation and taste for the posterior 1/3rd including circumvallate papillae – glossopharyngeal Posterior most part of the tongue vagus nerve.

Question 5. Pathways of taste.
Answer:

First-order neurons:

• Taste fibers of the facial nerve (VII), glossopharyngeal (IX) nerve, and vagus (X) nerve run, into the nucleus of tractus solitarious (NTS) in the medulla.
• The cell bodies of the second-order neurons are located in NTS and their axons ascend to join the medial lemniscus and terminate with V nerve fibers in the posteroventral nucleus of the thalamus.
• The third-order neurons arise and end in the inferior part of the ipsilateral postcentral gyrus.

Question 6. Tuberculum impair.
Answer:

• The medial ends of the two mandibular processes are separated by a midline swelling.
• This is called tuberculum impar.
• Immediately behind it, the epithelium proliferates to form a down growth (thyroglossal duct) from which the thyroid gland develops.
• The site of this downgrowth is subsequently marked by a depression called foramen caecum.
• The anterior two-thirds of the tongue is formed by the fusion of the tuberculum impar and the two lingual swellings.

Question 7. Submerged teeth.
Answer:

• They are ankylosed deciduous teeth usually located in the mandibular posterior region.
• They occur since the occlusal table of the retained smaller-sized tooth is located below the occlusal plane of the rest of the teeth in the arch.
• It is merely a deciduous tooth.
• It may occur because of the congenital absence of an underlying permanent tooth.
• Normally the surrounding permanent teeth which have erupted earlier, lock the submerged deciduous molar in its original position.

Question 8. Super numerary teeth.
Answer:

• The presence of any extra tooth in the dental arch in addition to the normal series of teeth is called supernumerary teeth.
• It may develop from
• Accessory tooth bud
• Splitting of the normal tooth bud
• It is more common in the maxilla.

Super numerary teeth Types:

• Mesiodens
• Distomolars
• Paramolars
• Extra lateral incisors.

Question 9. Infantile swallowing.
Answer:

• It is limited to breastfeeding.
• During it, the tongue is positioned over the lower gum pad protruding between the lower lip and nipple.
• Through it, milk is directed to the pharynx by the peristaltic movement of the tongue and mylohyoid.
• Passage of milk occurs between buccal pillars and lateral channels of the pharynx.
• It is transformed to mature swallowing.

Question 10. Freeway space
Answer:

• During rest position, space exists between the upper and lower teeth
• This is called freeway space

Freeway space Value:

• It should be 2-4 mm

Freeway space Significance:

• If it increases, the vertical dimension at occlusion reduces and becomes inefficient
• If it decreases, the vertical dimension at occlusion increases to a great extent

Question 11. Odland bodies
Answer:

• It is a small organelle formed in the upper spinous and granular cell layer
• It is a coating granule, glycolipid in nature
• It has an internal lamellated structure
• Its contents get discharged into the intercellular space forming an intercellular lamellar material that contributes to the permeability barrier
• This barrier is formed between granular and cornified cell layers