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 .

Skull: It is defined as the Skeleton of the head.
It is also called as cranium
All the bones in the skull are joined immovably by joints known as sutures, But with an exception the mandible which is joined by the movable Temporomandibular joint(TMJ)
Skull is divided into 2 main parts:
1) Brain box/calvaria- upper part of the skull which encloses the brain
2) The other part include the facial bones +mandible

Study of skull is divided into 2 main types:

1) Outside they can be studied in 5 different views:

Norma verticalis- Superior view
Norma basalis- Inferior view
Norma frontalis- Anterior view
Norma Occipitalis- Posterior view
Norma Lateralis- Lateral view

2) Inside view is studied by removing the roof of the Brain box (calvaria) known as skull cap

Gingivitis: It is the Pathological condition  of the gingiva(soft tissue surrounding the tooth). It is caused by the bacteria which causes plaque. It is a type of Periodontial deisease.

Symptoms: Gingivitis is mainly seen with the following conditions

• Swollen gums
• Bleeding gums
• Normal hard pink gums turn to reddish soft
• Foul smeel starts emmiting from mouth

Theory behind Gingivitis: The symptoms seen in gingivitis is inflamatory response of our body towads the bacteria which have invaded the soft tissue, Macrophages are the main cells which act on these bacteria by increasing in number rapidly and engulfing the bacteria and killing them, which causes the gums to swell.

Preventing Gingivitis: As i always say “Prevention is better than Cure”

• Good oral hygiene
• Regular dental checkups
• Preventing plaque formation by doing regular brushing and flossing.

Braces-These are the corrective appliances used to bring the teeth,
jaw bone, jaw joints and lips and musculature into proper
alignment mainly to improve the aesthetics of a person.
Basically the word braces is a layman’s term used for orthodontic
braces which are made of medical grade stainless steel metal totally       harmless to our oral cavity.

 Orthodontics- It is a branch of dentistry dealing with prevention
and correcting of irregular arranged teeth with malocclusion,                   Retrognathism, Prognathism of the jaw and teeth, by means of braces.

There comes the need for orthodontic treatment when one has crooked
and overlapping teeth or in case of wide gaps or in people with
malocclusion as they cause destructive dental plaque, cavities
and gingivitis etc..
Many people simply go for braces to look good when they are not satisfied with their teeth and want to look better.

Used when- crowding, overlapping, malocclusion, gaps,
thumb n finger sucking, mouth breathing, Prognathism, Retrognathism etc

Other Information-They are usually suggested at the age of 10-12
after all the deciduous teeth are shed off
but teeth can be pulled together at any  age hence people of all age
group can undergo the treatment, but most preferably the lower the age the better.

Types of braces: There are many types of braces according to the patients requirements

Metal braces, ceramic(aesthetically tooth colored), lingual braces.

Components- It deals with brackets which are fixed on
tooth labial surface and wires connecting the brackets and molar brackets
molar bands providing support to the wires as the treatment proceeds the
weight of wire goes on increasing starting from a light weight wire, the brackets are pulled together with the help of elastic rubber bands which are used based on the amount of pressure required.
Now a days ceramic braces are being used which are tooth coloured and made of
translucent material due to their cosmetic appeal.

How Braces Work: When the braces are put on the teeth they apply some amount of pressure which enables the bone present in our mandibular and maxillary arches to adjust to the change in the position, as there are osteoclasts which resorb the the bone on the side the teeth are moving  and the osteoblasts which lay down new bone on the side where the pressure is being applied, so the teeth move approximately 1mm per month but it depends on the patient oral condition and the efficiency of the orthodontist, So we can see a noticeable change in the positioning of the teeth overtime.

Treatment and Post treatment:  During treatment the most important problem is oral hygiene which leads to the formation of plaques in teeth as food is accumulated in  the metal braces, so proper brushing and flossing should be done daily and most preferably after each meal brushing is required.

Sometimes the metal in the braces or the latex material act as an irritant to the patient if he or she is allergic to it, During treatment some types of food are avoided which cause inconvenience to maintain hygiene and can cause damage to the braces, Sticky substances like chewing gum, toffee, hard substances, carrots are avoided.

Post treatment that is when the braces are removed from the mouth of the patient, Retainers are used to prevent the teeth from moving back to their original position(Relapse), So it is better to follow the instructions of the doctor or else the treatment will be prolonged and will be inconvenient to the patient.

The duration of the treatment varies according to the severity of the deformities and  the efficiency of the doctor.

In Dental Histology as you can see from the name we deal with

-Dental: about the tooth and its surrounding structures

-Histology: study of the microscopic structures like the cells and fibers in the tooth structure

So in dental histology we deal with the microscopic study of the structures of the tooth and the structures in the oral cavity surrounding the tooth.

Content:

Theory:

1. Enamel

2. Dentin

3. Pulp

4. Cementum

5. Periodontal ligament

6. Oral mucous membrane

7. Salivary glands

 Practical:

1. Demonstration of preparation of dental tissues for microscopic Examination. Ground and its stained sections

2. Microscopic study of normal oral and dental tissues

3. Microscopic study and identification of teeth