Factors affecting the growth of teeth and the reasons for their impact

Stated theories about how teeth grow

Currently, two theories have been proposed about how teeth grow.

1. The forces that cause tooth growth all come from the same source.
2. Teeth are pushed towards the oral cavity by forces which are:

(a) Root growth and increase in the number of odontoblast cells

As a result of the growth and development of the root and the increase in the amount of odontolast cells, the volume of the dental papilla increases, which causes pressure on the surrounding tissues, and as a result, the tooth is pushed towards the oral cavity.

(b) Changes in the dental pulp

It is believed that due to the increase of dental papilla cells and the formation of the root, the pulp space decreases, and as a result, the blood pressure in the pulp vessels increases, and as a result, the tooth moves towards the oral cavity due to the increase in this pressure.

(c) Changes in the connective tissue around the tooth

According to this theory, with the development of fibroblasts, the concentration and density of the collagen fibers in the periodontal fibers increases, and because the junction of the fibers in the bone is higher than the junction of the same fibers with the tooth, the contraction of these fibers pushes the tooth towards the oral cavity. .

(d) Changes made in the alveolar bone.

We will skip this part , because it’s out of our subject.

(e) Development of tooth apex tissues

According to some researchers, the connection between the soft tissues around the root and the bone at the end of the root can be a factor in tooth growth; In this way, first the tissue at the end of the root increases and pushes the tooth up, and then the bone is built from below, and the repetition of this process continues until the tooth grows out.

Of course, there is still no conclusive reason to prove any of the above opinions. These opinions are only obtained from experiments on laboratory animals and it is not known that there is an example in humans, but we know that tooth growth is not a continuous phenomenon, and undergoes different stages of stagnation and is movement

What is the cause of teeth recession?

The gradual decrease in the jaw size of today’s humans, which can be due to various reasons such as a change in the type of nutrition from a strict diet to a male, racial mixing and other factors during the past periods, has caused the teeth to adapt to the jaw size, for example, the third molar. In today’s humans, it is disappearing, in some people, even its bud has not formed, and in many people, the third large molar has remained latent.

In general, the factors that cause tooth decay can be divided into two categories: local factors and general factors

1- Local factors

Extra teeth

The presence of cysts, tumors and remaining roots of milk teeth
Abnormal tooth shape and size
This problem causes this tooth to not fall out easily, and as a result, it causes a delay in the growth of permanent teeth.
Ankylosis baby teeth that remain on the jaw longer than usual cause the growth of permanent teeth to be delayed.

Dislocation

A situation in which a tooth protrudes too far from its place is called misplaced (like a canine tooth that protrudes into the nasal cavity or eye socket.

Strike

When a part of the jaw is hit. It may cause displacement of the teeth inside the jaw and cause a delay in their growth. Sometimes the impact causes the tooth to get ankylosed inside the jaw and cannot come out.

Early loss of milk teeth

If a baby tooth is lost much earlier than usual, the permanent tooth below it may come out later than usual, and if a baby tooth falls out a little earlier than normal, the permanent tooth may also come out earlier than usual.

Not enough space for teeth

When a tooth does not have enough room to come out, its vegetative movement slows down. Although the teeth finally come out in crowding, there are also cases where the path of tooth growth is completely deviated and the tooth remains in the jaw. This issue is seen more in the case of lower second premolars if the milk second molars are extracted earlier than usual. The first large molar also deviates towards the mesial side, often there is no life left for the second small molar and this tooth erupts late.

2- General factors

In addition to local factors, a group of general factors are also effective, and here we mention the general factors effective in teeth growth.

Hypothyroidism

Cretinism patients have short arms and legs and the limbs are not proportional. From the dental point of view, the baby teeth of a Curtin child come out later than usual and fall out later than usual. Permanent teeth also come out later because the child’s jaw is small and the teeth are crowded.

Hypofunction of the pituitary gland

The crown size of permanent teeth in these patients is normal; Because there was no abnormality at the time of crown formation. Delayed growth in these patients is quite evident. In the severe form of this disease, the roots of milk teeth do not decay and it is possible to remain in the jaw for the rest of their lives. Permanent teeth are formed inside the jaw, but do not grow in the mouth. Extraction of milk teeth will not have any effect on the eruption of permanent teeth.

Marble bone

It is a rare disease whose cause is unknown, but it is often seen as hereditary. In this disease, due to the sclerotic nature of the jaw bone, teeth are delayed in growing.

Cleidocranial dysostosis

The teeth are delayed in growing and some of them remain in the jaw. If the permanent tooth is close to the surface, the baby teeth should be pulled.

Rickets

Teeth are delayed in growth, which is due to lack of vitamin D.