Wisdom teeth (third molars) are the last teeth on both sides of the dental array in the upper and lower jaws. They emerge last, most often in the late teens and early twenties of life, however, variations in the time of their emergence are most common compared to other teeth. The popular term "wisdom teeth" comes from the fact that they grow later than all other permanent teeth, in the years when their owners are probably wiser than children.
In some people, wisdom teeth never grow and can't be seen in the oral cavity. One of the reasons for their absence in the mouth may be that the tooth bud from which the tooth develops does not exist at all. Another possibility is that the tooth is located in the jawbone, but cannot fully develop into the oral cavity, or only partially emerges.
Such undeveloped or partially developed teeth are professionally referred to as impacted or semi-impacted teeth. The main reason why the tooth cannot grow is due to the existence of some mechanical obstacle that prevents it from settling into the tooth arch. One of the obstacles to normal development can simply be the lack of space in the jaw. Also the wisdom tooth can protrude obliquely and grow in the wrong direction, towards the adjacent tooth in front of it.
Partially-grown wisdom teeth can be observed and diagnosed very simply, by a clinical examination. One or more lumps may have penetrated through the gum or a part of the tooth has emerged in the oral cavity, and part is covered by the gum. An X-ray, most often taken by an orthopaedic camera, accurately determines the position of the teeth and how much is in the bone. An orthopantomogram, an X-ray of both jaws is practical, because one shot gives an insight into the position of all the teeth, including all four wisdom teeth, on both sides of both jaws. The problem with half-grown wisdom teeth is that they are partially covered by gum tissue, under which food enters and is retained. At home, it is almost impossible to clean such teeth and remove deposits from under the gums, and there are repeated soft tissue inflammations around the teeth which is manifested by pain and swelling. Over a long period of time, such teeth also develop a cavity that can spread to the central part of the tooth (the "nerve"), causing distinct pain. In these cases, it is advisable to remove the tooth, after which, all symptoms cease.
Wisdom teeth which have not developed at all can cause unpleasant symptoms, but not necessarily so. If they do not create an interference and if it is highly unlikely that they will cause any interference in the future, it is not necessary to remove them. However, sometimes, due to their oblique or completely horizontal position, they press on the tooth in front of them and can damage its root, thus endangering its survival in the oral cavity. An obliquely placed wisdom tooth can also, although very rarely, press on a nerve that passes through the bone of the lower jaw and cause extreme pain. If the wisdom tooth has penetrated the bone but is completely covered by gum tissue and is undetectable by clinical examination, food deposits can still lie behind the last tooth in the row and fall behind the gum that covers the wisdom tooth – this is also when severe inflammation can occur and recur, which can even lead to difficulties in opening the mouth.
In the case of impacted teeth, especially those which sit in an unusual position, it is sometimes necessary to perform a CT scan, in addition to an orthopaedic x-ray, to determine with certainty their exact position and orientation in the bone and the relationship between any adjacent teeth and the nerve. The tooth extraction procedure itself can be either simple or complicated, depending on the position of the teeth, and it is called an alveotomy. The procedure is performed under local anaesthetic, completely pain-free, and part of the bone is removed to facilitate access to the tooth, after which the tooth is removed with pliers and extractors, and sutures are then inserted to close the wound. The length of recovery depends on the complexity of the procedure, and the sutures are removed after 2 weeks. The empty space created after extraction of the wisdom tooth is filled with new bone in a period of several weeks.
