Stages of a loose tooth

December 06, 2022

  

Mobility is a term used in dentistry to refer to a tooth that is loose or moving. The tooth is affixed in the bony socket by a tissue complex called the periodontium. It comprises of the gingiva, cementum (outer layer of the roots of the tooth), alveolar bone (underlying bone) and periodontal ligament (ligament connecting bone to the socket). There are two types of tooth mobility - physiologic and pathologic.

Physiologic tooth mobility is seen in milk teeth. This occurs when the roots of the milk teeth get gradually resorbed due to the eruption forces of the underlying successor tooth. As the roots dissolve, the tooth becomes more and more mobile until it is finally pushed out by the permanent tooth. Apart from this teeth, physiologic tooth mobility can also be seen in healthy teeth where there is a 0.25 mm movement of the teeth.

Tooth mobility is also considered physiologic during the final week of gestation. The hormonal changes during this period directly affect the periodontium in a way that tooth mobility increases.

Pathologic tooth mobility in a tooth is because the tooth is affected by some pathology. A carious tooth might become entirely infected, leading to the formation of a lesion at the apex of the roots. The infectious lesion dissolute the roots thereby gradually making the tooth loose in its socket.

Trauma is another reason for a tooth to become mobile. A forceful blow can cause fracture in the structure of the tooth and the fibres that connect it to the socket. This makes it loose within the socket.

Patients suffering from a bone disease or with nutritional deficiencies are at a constant risk of pathological loss of tooth. Diseases of the bone like osteonecrosis can also trigger loss of attachment from the tooth, leading to its mobility.

Patients diagnosed with oral cancer are at a risk of suffering from inflammatory lesions of gingiva and the periodontium. These inflammatory changes can result in recession of the gingiva and loss of attachment which leads to tooth mobility. Moreover, these patients frequently receive radiations during their treatment which further makes them susceptible to osteonecrosis.

Abnormal oral habits like teeth clenching or bruxism, digit or thumb sucking, exert unnecessary forces on the underlying ligament and fibres which eventually rupture and loosen the tooth in its socket.

Dental treatments like braces can also cause mobility of teeth if it is uncontrolled. Restorations or fillings if done above the level of normal bite can also exert unwanted pressure on the underlying ligament, leading to tooth mobility.

A tooth does not become mobile immediately. Depending on the cause of the mobility, the tooth loosens in the socket. Initially, the fibres attaching the tooth to the bone begin to rupture. Gradually, the surrounding blood vessels in the form of microcapillaries begin to rupture, increasing the pressure on the roots. In the next phase, the tooth gradually begins to displace from the underlying alveolar bone.

Dentists analyze the mobility of tooth by two methods. It can be checked by applying light finger pressure on the tooth. Another method is to use the blunt end of an instrument from one side and a finger to support the tooth on the other side to check for mobility.

The extent of mobility is then graded based on how much millimetres and in what direction the tooth moves in the socket. Grade 1 mobility indicates slight tooth mobility. Grade 2 is when the tooth moves 1 mm within the socket and Grade 3 is severe mobility where the tooth is mobile more than 1 mm in the socket and is also depressible.

There are at least ten other methods through which tooth mobility can be assessed. However, it is the clinician's expertise and judgement of mobility assessment, upon which he or she decides the treatment options for the same. Teeth with less mobility can be splinted with adjacent teeth. Teeth with poor prognosis and excessive mobility need to be extracted.

Pathologic tooth mobility must always be addressed at the earliest. If left mobile, it can hamper the underlying tissues, persist and infect the surrounding tissues and may even cause injuries to the soft tissues of the oral cavity.

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