Teeth are the main units with which mastication is carried out.
They are directly involved in the grinding of food, thanks to their curved or sharp edges. Depending on the role of the tooth in performing its functions and its position in the dental arch, they have an individual morphology.
In addition to their role in mastication, teeth also help to preserve the physiognomy, achieving equality between the levels of the face.
This is why, especially in patients who have lost their teeth, the lower tier appears much shrunken, identifying with the ‘old’ appearance.
The teeth also contribute to phonation, so that when pronouncing certain consonants, the tongue rests on the teeth, helping to pronounce them clearly.
The forces that are produced during the exercise of functions, and especially during mastication, are transmitted via the teeth to the supporting bones, i.e. the jawbone and mandible.
These impulses promote bone growth and development. A bone that is not stimulated will eventually atrophy.
The same happens to bone in toothless areas. Without stimulation, it thins out, reduces its vertical and horizontal dimensions and creates problems for subsequent prosthetics.
The dental envelope is the boundary between the dental crown and the roots.
While the dental crown is that portion of the tooth exposed to the oral environment and visible to the naked eye, the root is located deeper in the alveolar bone and helps to ensure that the teeth remain well implanted.
The dental envelope can be appreciated in two ways:
The anatomical envelope – which represents the anatomical limit between the root and the crown, i.e. the meeting point between enamel and cement. Cementum is the external layer of hard dental tissue that covers the roots and has features in common with the enamel of the crown.
The clinical envelope – which represents the meeting point between the tooth and the gum, i.e. the limit up to which the ligaments that ensure the anchoring of the gum rise to the level of the dental crown. The clinical envelope is visible directly in the oral cavity, without the need for imaging.
The collar may be positioned differently in the teeth, depending on several factors. Firstly, the morphology of the tooth dictates the location of the collar.
On the other hand, the location of the socket varies with age.
The longer the tooth, the closer the clinical dental collar is to the root.
In child and young adult patients, the clinical collar is located higher than the anatomical collar.
This is due to the periodontal ligaments, which have a good, unaffected insertion, making the root fit closely to the teeth.
As the patient advances in age, the level of the dental collar changes.
The gum may gradually detach from the tooth and migrate towards the roots due to the mechanical trauma it is subjected to or due to the onset of periodontal disease, which destroys the quality of the ligaments.
Thus, the tooth will appear to have a much more elongated crown. With this phenomenon, the quality of the implant also decreases.
As the degree of bone coverage of the root decreases, tooth mobility increases.
In borderline situations, when the collar is very close to the root tip and the tooth has high mobility, the tooth will be lost.
Therefore, any condition must be treated and monitored so that the teeth can be kept on the arch as long as possible.
