This condition is also called as Edentulism. This is a condition where there are no teeth left in the oral cavity and all the teeth have fallen.

In this condition there will be great difficulty for the patient to chew any kind of hard food as the mucous membrane of alveolar ridge will be exposed and the patient has to get complete dentures.

There will also be shrinkage of the mandible inwards and the aesthetics of the patient will be affected very badly, and it also gives a very aged look to the patient, so the sooner the dentures are put the better it is.

There will be problem in speech and pronunciation, so the quality of the speech and the communicating power of the patient is reduced.

The instruments used in Ist year of dentistry are mostly the technical instruments and some of the clinical instruments.

In Ist year we mostly learn the work done by technicians and learn about their work practically, so we use the instruments used by them which are non clinical.

The instruments used are:

1) Macintosh sheet: This is a rubbery material, which is very rigid and is used to keep the surroundings clean from the work done.

2) Plaster Spatula: This is a broad bladed spatula which is used to mix the Plaster of Paris in an efficient way. There re 2 types of these spatulas: 1) Straight

Curved Spatula: This is similar to the straight spatula but the only difference is that it has a slightly curved blade which helps in mixing the contents of the bowl by pressing against the walls of the bowl.

3) Plaster Knife: This is an instrument which is used to handle the plaster of paris and apply it in a way which is needed.

4) Rubber Bowl: This is a bowl made out of rubber which is elastic to some extent and help in easy and good mixing of the plaster of paris and also an Alginate(Impression material) .

5) Cement Spatula: This is a clinical instrument which we use in our daily practice,It has a wide bladed face and a long handle so that there is a big surface area to mix the liquid and the powder of the cement to get an appropriate mix. And apply them into the prepared cavities to get the tooth structure back to its original state.

6) Agate Spatula: This is also used to mix dental cement but it is made out of plastic, as there are cements which react with the metal of the steel spatula, mailny this spatula is used to mix GIC ( glass inomer cement)

7) Glass Slab: It is used to mix the constituents of the cement together in a proper way and to get a flat surface to mix on, So it is used as a platform to mix the cements.

8 ) Lacron Carver: It is an instrument which has a blade on one side and a scoop like thing on the other side of it. It is an instrument used in Dental anatomy practicals where we have to carve teeth out of the wax blocks.

9 ) Stainless Steel Scale:

10) Impression Trays: These are metal trays which are used to carry the Impression material into the mouth and give support to the impression material so that there is a good impression (or) a replica of the oral cavity.

The Impression Trays are of 2 main types:

1) Dentulous: These are trays which are used to take impressions of people with teeth or of a dentulous mouth.

2) Edentulous: These are trays which are used to take impressions in an edentulous mouth or a patient without teeth.

The are again divided into two types, based on the presence of perforations in it:

1) Perforated: There are small perforations or holes in the tray.

2) Non-Perforated: There are no perforations in the trays as they are used to carry impression materials which are not rigid Ex. Alginate.

We learn about these Dental instruments as we need have a insight into our profession.

Permanent teeth are the set of teeth which replace the Deciduous teeth, the permanent teeth are more in number and are comparatively larger than the deciduous teeth.

These are called the Permanent teeth because these are the last teeth to erupt and there will be no new growth of teeth in the oral cavity after these teeth are lost.

There are a total of 32 permanent teeth present in the oral cavity of an adult human being, There are

• Incissors - 8
• Canines - 4
• Premolars - 8
• Molars - 12

To know the positioning of the teeth look at the picture given in the post.

Deciduous teeth also known as the Milk teeth are the set of teeth present in children. These teeth are present upto the age of 12 in most of the children but can vary in some individuals, There are mainly 5 teeth in each Quadrant in the oral cavity.

The teeth missing are both the Pre molars and the 3rd molar

The teeth present are: Incisor

Canine

Molars

Refer to the picture to get a clear view of the dentition .

Salivary Glands: These are the secretory glands or the Exocrine Glands which secrete a multi functional fluid known as Saliva.

Saliva which is a combination of many substances with varied functions is a slightly viscous fluid which is composed of many substances which are produced and secreted into the oral cavity by different salivary glands and mix in the oral cavity to form saliva in the mouth.

The salivary glands release their secretions into the oral cavity. These salivary glands are divided into 2 main types based on their position, size and the chemical nature of the secretory products:

1) Major Salivary Glands: 3 pairs of large glands located outside the oral cavity.

2) Minor Salivary Glands: Many numerous small glands in the mucosa and sub mucosa of the oral cavity.

Major Salivary Glands:
These are the largest of the salivary glands which are arranged in pairs, and supply their secretions into the oral cavity by the help of ducts which connect the galnds to the oral cavity.

1) Parotid Gland: It is present in front of the ear, It is connected to the oral cavity with the help of Stensons Duct which opens near the 2nd maxillary molar.

2) Submandibular Gland: It is present in the submandbular triangle. It is connected to the oral cavity by Wharton’s Duct and it opens by the side of the lingual frenum on the floor of the mouth. It is a mixed gland which secrets both serous and mucous secretions.

3) Sublingual Gland: As we can see by the name Sub-below, Lingual- tongue so it is present below the tongue, It is connected to the oral cavity by the Bartholins Duct, It is also a mixed gland.

Minor Glands:
1) Labial and Buccal Glands: The glands of the cheeks and lips.

2) Glossopalatine Glands: These are present in the Isthmus in the glossopalatine folds, these are purely mucous glands.

3) Palatine Glands: Present in the Lamina Propria of the posteriolateral region of the hard palate and in the sub-mucosa of the soft palate.

4) Lingual Glands: These are known as the glands of the tongue, they are of 2 types the anterior lingual glands and the posterior lingual glands.

Functions of Saliva:
1) It initiates the process of Digestion, we can also say that it starts the first stage of digestion.

2) Maintains the oral hygiene, by killing some of the pathological microbes.

3) Lubricates the food and helps in easy swallowing by making the food into a mass of semi digested food known as ‘Bolus’.

4) It maintains the oral cavity and helps in the easy movement of the tongue which help in proper speech.

5) It has anti microbial function as it contains the Immunoglobulins which kill the bacteria and act as the first line of defence .