Tooth mobility is the horizontal or vertical displacement of a tooth beyond its normal physiological boundaries around the gingival area, it is also termed as a loose tooth. Destruction of the supporting tissues of the teeth may progress to necrosis or tissue death of the alveolar bone, which may result in a decrease in the number of teeth. The decrease in the number of teeth of a patient may decrease the chewing ability. They may also experience pain and dissatisfaction with the appearance, decreasing their quality of life.
Mobility is graded clinically by applying pressure with the ends of two metal instruments for e.g. dental mirrors and trying to rock a tooth gently in a bucco-lingual direction i.e. towards the tongue and outwards again.
Using the fingers is not reliable as they are too compressible and will not detect small increases in movement. The location of the fulcrum may be of interest in dental trauma. Teeth which are mobile about a fulcrum half-way along their root likely have a fractured root.
Normal, physiologic tooth mobility of about 0.25 mm is present in health. This is because the tooth is not fused to the bones of the jaws, but is connected to the sockets by the periodontal ligament. This slight mobility is to accommodate forces on the teeth during chewing without damaging them.
Milk teeth or deciduous teeth also become looser naturally just before their exfoliation. This is caused by gradual resorption of their roots, stimulated by the developing permanent tooth underneath.
Grace & Smales Mobility Index
- Grade 0: No apparent mobility
- Grade 1: Perceptible mobility <1mm in buccolingual direction
- Grade 2: >1mm but <2mm
- Grade 3: >2mm or depressibility in the socket
- Class 1: < 1 mm (horizontal)
- Class 2: > 1 mm (horizontal)
- Class 3: > 1 mm (horizontal+vertical mobility)
Causes Of Mobile Teeth
There are a number of pathological diseases or changes that can result in tooth mobility, some of them are stated below
Periodontal disease is caused by inflammation of the gums and the supporting tissue due to dental plaque.
Periodontal disease is commonly caused by a build up of plaque on the teeth which contain specific pathological bacteria which produce an inflammatory response that has a negative effect on the bone and supporting tissues that hold the teeth in place.
One of the effects of periodontal disease is that it causes bone resorption and damage to the supportive tissues.
This then results in a loss of structures to hold the teeth firmly in place and they then become mobile or loose.
In cases where periapical pathology like cysts and tumors the teeth may have increased mobility. Severe infection at the apex of a tooth can again result in bone loss and this in turn can cause mobility. Depending on the extent of damage the mobility may reduce following endodontic treatment.
Osteonecrosis is a condition in which lack of blood supply causes the bone to die. It mainly presents following radiotherapy to the jaw or as a complication in patients taking specific
anti-angiogenic drugs. As a result of this necrosis the patient might experience several symptoms including tooth mobility.
Oral cancer is a malignant abnormal excessive growth of cells within the oral cavity, which arises from premalignant lesions through a multistep carcinogenesis process.
Most of the oral cancers involve the lips, lateral border of the tongue, floor of the mouth, and the area behind the third molars i.e. the retromolar area.
Symptoms of oral cancer can include velvety red patches and white patches, loose teeth and non-healing mouth ulcers.
The risk factors of oral cancer may include caries prevalence, oral hygiene status, dental trauma, dental visit, stress, family history of cancer, and body mass index (BMI), etc.
Habits such as tobacco chewing/smoking and alcohol are the major causative agents, although human papillomavirus has also recently been implicated as one of them.
Oral cancers have a range of symptoms including red and white patches, ulcer and non-healing sockets. Another symptom that patients might experience is loose teeth with no apparent cause.
Bruxism, which is an abnormal repetitive movement disorder characterised by jaw clenching and tooth grinding, is also a causative factor in the development of dental issues, including tooth mobility.Although it cannot cause periodontium damage in itself, bruxism is known to be able to worsen attachment loss and tooth mobility if periodontal disease is already present.
Dental trauma refers to any traumatic injuries to the dentition and their supporting structures. Common examples include injury to periodontal tissues and crown fractures, especially to the central incisors. These traumas may also be isolated or associated with other facial trauma. Luxation injury and root fractures of teeth can cause sudden increase in mobility after a blow.
Physiological tooth mobility is the tooth movement that occurs when a moderate force is applied to a tooth with an intact periodontium.
Causes of tooth mobility other than pathological reasons are stated below
Hormones play a vital role in the homeostasis within the periodontal tissues. It has been advocated for a number of years that pregnancy hormones, the oral contraceptive pill and menstruation can alter the host response to invading bacteria, especially within the periodontium, leading to an increase in tooth mobility.
Excessive occlusal stresses refer to forces which exceed the limits of tissue adaptation, therefore causing occlusal trauma. Tooth contact may also cause occlusal stress in the following circumstances:
Parafunction or bruxism
Dental treatment and periodontal disease.
Although occlusal trauma and excessive occlusal forces does not initiate periodontitis or cause loss of connective tissue attachment alone, there are certain cases where occlusal trauma can exacerbate periodontitis.
Primary tooth exfoliation
When primary teeth are near exfoliation (shedding of primary teeth) there will inevitably be an increase in mobility. Exfoliation usually occurs between the ages of six and thirteen years. It usually starts with the lower anterior teeth (incisors and canines); however, exfoliation times of the primary dentition can vary. The timing depends on the permanent tooth underneath.
The treatment of tooth mobility depends on the etiology and the grade of mobility. The cause of mobility should be addressed to obtain an optimal treatment outcome.
For example, if the tooth mobility is associated with periodontitis, periodontal treatment should be carried out. In the presence of a periapical pathology, treatment options include drainage of abscess, endodontic treatment or extraction.
Occlusal adjustment is the process of selectively modifying occlusal surfaces of teeth through grinding to eliminate disharmonious occlusion between upper and lower teeth.
Occlusal adjustment is only indicated when mobility is associated with periodontal ligament widening.
Occlusal adjustments will be unsuccessful if the mobility is caused by other etiology such as loss of periodontal support or pathology.
This is the procedure of increasing resistance of tooth to an applied force by fixing it to a neighboring tooth or teeth.
Splinting should only be done when other etiologies are addressed, such as periodontal disease or traumatic occlusion, or when treatments are difficult due to the lack of tooth stabilization.
Splinting allows healing and functions during tissue healing.
The main disadvantage of splinting is it makes removal of plaque more difficult, as there will be increased plaque retention at the margins of the splint, which can cause periodontal disease and further loss of periodontal support.
A dental splint works by evening out pressure across a patients jaw.
A splint can be used to protect teeth from further damage as it creates a physical barrier between lower and upper teeth.
In order to treat mobility, teeth can be joined or splinted together in order to distribute biting forces between several teeth rather than the individual mobile tooth.
A splint differs from a mouth guard as a mouth guard covers both gums and teeth to prevent injury and absorb shock from falls or blows.-