Wisdom teeth, when to keep them and when to remove them. The words of the expert

If until some time ago the extraction of a wisdom tooth was taken lightly or often tended to be conserved, modern dentistry has taken seriously these last molars, which develop in old age. As the professor explains Giulio Gasparini, Maxillofacial Surgeon, Head of Pre-prosthetic Surgery Unit Agostino Gemelli Institute, Rome, there are many problems that are encountered by keeping them. Similarly, the surgery must be performed by experienced professionals because it is not without contraindications.

Professor, what are wisdom teeth for?

“Also called third molars, they are the last permanent teeth that appear between the ages of 17 and 25. They are defined as III molars or wisdom teeth precisely because they appear at an age in which it is hoped that the person is “wiser”. Anthropologists believe these were particularly useful for our prehistoric ancestors, who needed a powerful chewing apparatus to eat plants, hard seeds, and foliage that primarily made up their diet. When other teeth wore out or fell out, the wisdom teeth intervened to provide a major replacement. Although today we have a totally different diet, in addition to preventive dental care, in theory we no longer need wisdom teeth. But natural evolution is infinitely slower than that of technological progress, which is why our chewing system is adapting very slowly to lifestyle changes “.

So what happens?

“The growth of the brain has reduced the space for the bones of the face and in particular for the maxilla and the mandible. This reduction associated with less stimulation by food (we no longer chew seeds or roots, ed) has meant that wisdom teeth find less and less space inside the oral cavity, and for this reason they remain trapped under the gum or under the bone. It is estimated that 70-80% of adults still have wisdom teeth and of these at least 50-60% are affected by the ‘malposition’. It is for this reason that the extraction of the wisdom tooth represents one of the 10 most frequent causes of surgery in day surgery, and in some hospitals over 90% of surgical activity “.

This is why they often have to be taken off?

“The normal growth of the tooth involves a first phase of crown formation and a subsequent one formed at the same time by the formation of roots and a tooth coming out into the oral cavity. As it grows, it is pushed outwards from the bone until a when it comes out of the gum and is positioned in the posterior part of the maxilla or mandible. When the wisdom teeth are well positioned in the dental arch, they generally do not create major problems. the tooth tilts either forward or backward, effectively preventing the normal future development of this last molar “.

What damage can this abnormal development cause?

“In these conditions the tooth continues to grow pushing on the others and in some cases it can move them or create the conditions for the nearest tooth to undergo decay. The same thing happens to the roots that failing to push the tooth outwards, deform to create angles or hooks that in severe cases can touch the inferior alveolar nerve. This is the nerve responsible for the sensitivity of the lip and lower part of the face. In other cases the tooth cannot come out due to lack of space completely and remains partially covered by a layer of gum. In these cases the painful symptoms are due to the fact that the patient is unable to clean the bacterial plaque, which accumulates under the gum, which over time becomes infected and mucosa becomes inflamed and swollen. Usually for the pain you avoid brushing that area and the inflammation becomes more and more important until it becomes a real infection . Furthermore, the swollen mucosa traumatizes the antagonist teeth (those that come into contact in occlusion, or the closure of the two dental arches, ed) every time the patient tries to close his mouth. Again, the wisdom teeth that remain inside the bone can be the cause of odontogenic cysts (they are a type of cyst that manifests itself in the form of small white or pinkish nodules, ed) that can reach very important dimensions and which in some cases can lead to a fracture of the jaw. Finally, in some cases the wisdom teeth do not show any sign of their presence but are accidentally discovered during x-rays performed for dental checks “.

While helping our prehistoric ancestors to eat, do wisdom teeth currently serve for chewing?

“They are often one of the first causes of temporomandibular joint dysfunction. This happens because they can cause occlusal precontacts during chewing (a condition in which the relationship between the two dental arches is not realized simultaneously on the antagonist teeth, but in a single or few teeth, ed) and these can generate movement disorders of the ‘articulation. Furthermore, in situations of not particularly large mouth, dental crowding can lead to a stressful condition creating the conditions for situations of bruxism (literally the grinding of the teeth, ed) of uncontrolled movements or muscular tension that can then lead to chronic disorders. of the temporomandibular joint with pain and difficulty in movement “.

Do wisdom teeth have to be removed at this point?

“No. If these are well positioned and can be cleaned easily and thus be maintained. In all other cases they must be removed and in particular:

  • in the case of orthodontic therapies for two reasons, the first is that there is the possibility that the wisdom tooth will respond to the teeth once they are aligned, and the second that orthodontic therapy could cause abnormal inclinations of the wisdom tooth with impediment to coming out
  • in case of temporomandibular dysfunction
  • in case of recurring infections
  • in case of own destructive caries (a type of caries that begins to expand with great depth in the tooth, ed) or of caries on the proximal tooth
  • in case of cystic neoformations

If the wisdom tooth is completely asymptomatic and does not create problems, in people over the age of 40 it can be left in place, but must be constantly monitored with dental checks and annual x-rays. Before the age of 40 it is always advisable to extract it, unless there are particular anatomical conditions that put the vascular-nerve structures or the maxillary sinus at great risk “.

How is the surgery performed?

“It can be performed either by the oral surgeon or by the maxillofacial surgeon, the important thing is that the operator has a proven experience in this type of surgery. The operation lasts about 30 – 40 minutes and these times should not be exceeded, to limit the duration of the anesthetic effect and the stress for the patient. It begins with incising the mucosa and removing the bone to expose the tooth. Then the tooth is crushed into several parts, to reduce the stress on the vascular-nerve structures, and the subsequent extraction of the various parts of the tooth from the bone. This is followed by the remodeling of the bone cavity and finally the suturing of the gum “.

How can surgery be dangerous?

“It can expose the patient to various complications. The most dangerous of all, because it is unsolvable, is a lesion of the mandibular nerve with loss of sensitivity in the lower lip or lingual nerve, with loss of sensitivity in the tongue. These complications are rare, we speak of 0.5 to 2%, but if they occur they are often unsolvable. On the other hand, transient reductions in sensitivity that resolve after a few days or at most a few months are much more frequent. Other serious complications, however, which can be resolved with appropriate therapy, are the fracture of the mandible, the dislocation of the dental element within the maxillary sinus, infections or hemorrhages. The risks are many but they can be considerably reduced by adopting all the surgical precautions that every expert operator in such a way puts in place. However, it should be noted that the benefits obtained from the removal of the wisdom tooth are much greater than the possible complications “.

To conclude, what advice can you give on wisdom teeth?

“In any case, that of turning to dental specialists or maxillofacial surgeons with proven experience with this type of surgery, as the risks involved are inversely proportional to the familiarity of the operating surgeon. On the other hand, when they give rise to painful symptoms, recurrent infections, cystic lesions, the risk of displacement of adjacent teeth or temporomandibular joint dysfunctions, they must be removed without delay “.

Professor Giulio Gasparini, maxillofacial surgeon

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