The structure, purpose, functions and diseases of small molars

Healthy people normally have 28 or 32 teeth, half on the upper and lower jaw. All of them are divided into the following types: incisors, canines, premolars and molars.

Each is unique in its own way: it has its own structural features that allow it to perform certain functions. Location also has a big impact on the biting and chewing process.

What are small molars

Premolars are teeth that are located between the canines and large molars. Located on the sides of the jaws. Also called small indigenous.

Small molars are very important - they are responsible for nibbling and chopping food. They have their own distinctive structure, which allows you to distinguish several varieties.

An adult should normally have eight premolars, 4 on both jaws. There are two first upper and two second ones, similarly on the lower jaw.

Structure, purpose and function

Premolars are a transitional type of teeth, from incisors to molars. Their structure is very interesting - they took part from the canines and part from the indigenous ones.

Small molars are prism-like. On the side of the chewing surface, there are two tubercles:

• vestibular is located close to the cheeks and is also called buccal;
• palatine looks into the mouth and is called lingual.

Features of location and structure allow these teeth to perform the following functions:

• grabbing, tearing and crushing pieces of food;
• grinding food.

Since small molars are involved in the process of grinding food, they can also be called chewing teeth. The premolars of the lower jaw are very similar in structure to large molars and are able to withstand a serious load, which allows them to participate in the chewing process.

In the absence of these teeth, food is grinded worse, larger pieces enter the stomach for digestion which requires more time and gastric juice, which inevitably leads to disruption of the gastrointestinal path. As a result, gastritis and peptic ulcer disease develop. Therefore, like the rest of the teeth, small molars should be treated in a timely manner and their loss should not be allowed.

Features and varieties

In children small molars are absent, and milk molars grow in their places. After renewal of milk teeth, premolars grow. This happens between the ages of 8 and 12.

It is interesting that the structure of the premolars of the upper and lower jaw, and even those located in the same row, differ from each other. The upper premolars have two roots, and the lower ones have one, but long. The size is also different - the largest first premolar is located on the upper jaw, and the smallest - the first on the lower. The similarity is the long fissure on each (natural depression, furrow, groove).

The shape of small molars changes depending on various factors - from the structure of the jaw, occlusion, the structure of the near teeth, etc. Premolars characterize the individual characteristics of a person.

There are the following types of small molars, depending on the size of the tubercles and the location in the mouth.

Upper jaw:

• enlarged buccal tubercle in comparison with the lingual;
• enlarged lingual tubercle in comparison with the buccal;
• tubercles of the same size.

Lower jaw:

• two tubercles (more often the buccal is superior to the lingual);
• three tubercles (the lingual is divided into two parts);
• four tubercles (buccal and lingual tubercles are divided into two parts);
• five tubercles (distal apex appeared).

The most common is the two-cusp structure of small molars. But the bumps themselves are not similar in appearance and structure to each other.

Consider the varieties of tubercles using the example of the lingual:

• almost invisible lingual tubercle due to the fact that it merges with the middle ridge;
• the lingual tubercle is in the middle of the tooth and therefore covers the fissure;
• the lingual tubercle is in the shape of a crescent, the fissure is bent in the same way;
• the well-defined contours of the lingual tubercle make it pointed.

Premolars have many features, they develop in each person in their own way. The existing variety of types of structure of premolars is natural and does not affect functionality in any way.

First top

This tooth is located next to the canine and is similar in structure to it. It has an irregular rectangular shape with rounded edges. The length can vary between 19-23 mm. On the buccal and palatal side, the first premolar is convex.

These teeth are characterized by a two-cusp structure. The palatine tubercle is usually much larger than the lingual. There is a deep fissure between the tubercles, which does not reach the edges. Enamel rollers are located along the edge of the chewing surface. There are also two stingrays. The one in front is more pronounced.

The first small molar on the upper jaw has two roots that branch off from one main root and diverge at the base. Roots can have one to three canals. Most often, two canals are observed in accordance with the number of root bifurcations. The flat shape has deep grooves along the root.

Second top

The second small painters of the upper jaw are located after the first. Big indigenous people grow behind them. In terms of its structure, the second premolar is very similar to the first, but smaller in size. Its length can reach from 20 to 24 mm.

The crown has a prismatic shape. There are two tubercles - buccal and lingual. Both tubercles are almost the same size, sometimes the buccal can be slightly larger than the lingual.

A fissure runs between the tubercles in the center. The buccal surface is much larger than the palatal. The buccal region is more convex in front than in the back.

Most often there is one cone-shaped root. It has wide lateral surfaces that are compressed anteroposteriorly. The branching of the root is quite rare.

First bottom

The first lower small molars are located near the lower canines. They have a rounded crown. The length reaches 22 mm. The upper part of the crown is directed towards the tongue. The vestibular surface is larger and convex in shape.

There are two cusps on the premolar. The buccal tubercle is visually higher and larger than the lingual. They are separated by a furrow. A ridge extends along the buccal surface to the lingual tubercle, which crosses the groove separating them. As a result, two pits are formed - medial and distal.

The unevenness of the tubercles led to the fact that the chewing surface acquired a beveled shape. Because of this, the tooth looks like a canine.

The root has one process and one canal, but there are cases of double canals that converge at the base. Usually the root has a rounded shape and curls into the jaw.

Second bottom

This premolar is located immediately behind the first and is located in front of the mandibular molar. It differs in its structure and shape from the first. The length can be 21-22 mm.

The buccal surface has a convex shape and a wide ridge. The lingual also has a roller. The tubercles have practically the same development, the buccal tubercles are slightly larger. The tubercles are separated by ridges, as a result of which dimples are present.

In the middle there is a fissure, which is capable of branching and dividing the tubercles. Thus, three- and four-cusp forms appear.

The chewing surface is more horizontal than that of the first lower premolar. The root of the second lower molar is almost always the same and has a conical shape. Its length is longer than that of the first.

Each small painter is different from the others. The first premolars are more similar to canines and help bite off food, the second are closer in structure and function to the molars.

Probable diseases

Small molars, like other teeth, can be negatively influenced by external factors. As a result, certain diseases of hard tissues occur. The peculiarities of the location of the small molars contribute to the fact that they can be subject to diseases that are characteristic of both incisors and molars:

1. Caries is the most common disease. It means the developing destruction of tissues with the appearance of a cavity inside the tooth. Most often, the lesion occurs on the chewing surface at the site of the fissure. Depending on the stage of destruction, the degree of enamel darkening and painful sensations differ. Treatment is performed by removing the affected tissue and filling the cavity.
2. Hypoplasiaenamels consists in the improper formation of tissues due to disruptions in the metabolic processes of the body. It manifests itself in various depressions, grooves, spots, mainly on the cutting surface of a small painter. There are manifestations in the form of partial formation of tubercles. Treatment consists of aesthetic correction with onlays, composites, veneers, etc.
3. Fluorosis is a chronic pathology. It develops as a result of excessive ingestion of fluoride, for example, in drinking water. As a result of fluorosis, enamel hypoplasia can also develop. Pathology is expressed in fragility, pigmentation, curvature of the shape of the teeth. The late stage of the disease is characterized by enamel erosion, thinning and curvature of the shape. Treatment also consists of aesthetic adjustments.
4. Erasing teeth is a slow thinning of the hard tooth tissue in specific areas. This phenomenon is typical for people over 30 years old. The abrasion process can affect enamel as well as dentin and pulp. The tubercles of all molars are subject to the greatest abrasion, but there are cases of abrasion of the anterior incisors and canines. This phenomenon can occur for the following reasons - dietary habits, mental illness, habits, profession, heredity, diseases of the endocrine system, etc. You can restore the original appearance with the help of an aesthetic treatment.
5. Wedge-shaped defect manifests itself in the cervical region of the vestibular part of the tooth. This phenomenon is typical mainly for incisors, canines and small painters. It refers to a non-carious change in hard tissue. Typical for middle-aged and elderly people. The reason may be disruption of the endocrine system, gastrointestinal tract, chemical and mechanical damage to the gums. It has been developing over the years. Initially does not bother the person. Over time, a large pocket appears and sensitivity to various stimuli appears. Sealing the exposed area closes the pocket and reduces sensitivity.
6. Hereditarydiseases are defective amelogenesis and dentinogenesis, which are manifested in defective development of enamel and dentin. Symptoms include discoloration of the enamel, tooth shape and size, increased sensitivity to stimuli, mobility, and translucency.

Any disease affects both the appearance of the tooth and its functionality. The destruction of hard tissues can lead to serious consequences from a violation of the integrity of the dentition to diseases of internal organs and systems.

Treatment should be aesthetic rebuilding the structure of the tooth and its functionality due to drug therapy and elimination of the underlying cause of the disease.

Summarize

Small molars play a very important role in the oral cavity in the oral cavity. Thanks to them, a person can bite off and grind pieces of food, their absence leads to disruption of the gastrointestinal tract and other serious diseases.

The structure of small molars depends on their location in the dentition and the jaw on which they are located. Due to their location, they can be subject to various destructions of hard tissues.