Introduction
Many dental emergencies are encountered by clinicians in their routine lives. These include bruises, tooth fractures, jaw displacements, and tooth mobility. This tooth mobility is an extremely difficult situation to handle since there are chances of tooth necrosis. In addition, there can be chances of destruction of surrounding structures. The key to the success of tooth mobility is the time of injury and grade. Splinting and root canal treatment (RCT) are commonly used dental treatment options. The chief aim of the clinician is to assess the severity of mobility and provide the best treatment so that tooth loss can be prevented.
What Is Dental Trauma?
Dental trauma is a common problem associated with both adults and children. Children mostly suffer from dental injuries in the age group of one to three years. The most affected teeth are lateral incisors and central incisors. If progresses further, leads to necrosis and loss of teeth. Adults mostly encounter mobility due to injury. Mobility is basically a common sign that is both multifactorial and unifactorial. It is often accompanied by spontaneous or continuous pain. The tooth is often lost due to either avulsion (extrusion of a complete tooth) or pulp hyperemia (increased blood flow in the pulp). The supportive structures like alveolar bone (especially the basal part), gingiva, and periodontium are sometimes irreversibly damaged. Hence, it becomes the utmost responsibility of the clinician to restore the lost attachment apparatus of the tooth.
What Are the Different Types of Tooth Mobility?
There are two main types of tooth mobility, physiological and pathological. Physiological tooth mobility is typically present in nearly all teeth, but it is minimal and usually goes unnoticed. On the other hand, pathological mobility arises from factors like trauma, injury, fractures, or infections such as cavities or periodontitis (inflammation of the tissue around the teeth). This type of mobility can be categorized into three major grades, as per Miller’s classification or Muhlemann (1954):
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Grade 1 involves slight horizontal movement, barely perceptible.
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Grade 2 entails horizontal movement within a range of approximately 0.07 to 0.11 inches.
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Grade 3 encompasses a vertical component of 0.039 to 0.07 inches.
Goldman and Prichard have introduced some modifications to these categories. Various factors can lead to tooth mobility, such as injury, pathologies like periodontitis, or irreversible pulpitis. Notably, periodontitis is responsible for around 50 percent of tooth loss due to mobility. Iatrogenic causes, such as orthodontic treatment or postoperative surgery, can also induce tooth mobility.
Besides the previously mentioned factors, tooth mobility has diverse causes. A clinical review on tooth mobility by Mittal et al. in 2012 highlights that mobility might be temporary due to loss of support resulting from multiple extractions. It can be adaptive, caused by changes in tooth support due to ill-fitting restorations, or reduced as a result of ankylosed teeth. This could be due to failed re-implantation or damage to the periodontal ligament. Additionally, mobility can manifest as hypermobility after periodontal surgery or as hypomobility (also known as residual mobility) due to periodontal ligament atrophy.
What Is the Pathogenesis of Tooth Mobility?
Physiological tooth movement is associated with the viscoelastic property of the periodontal ligament. Periodontal ligament stretches and elates on account of masticatory load. Hence, mobility is very minute or not even felt. But during pathology such as trauma or fracture, the periodontal or even gingival fibers (especially transseptal) are damaged irreversibly, resulting in loosening of teeth.
Sometimes, the injury is so severe that the tooth emerges from the socket and becomes permanently necrosed. Another factor is periodontitis, which leads to pathological migration, tooth flaring, and extraction. It is a slow but irreversible destructive process. In this, the periodontal fibers and alveolar bone are continuously destroyed. Finally, the tooth becomes extruded (comes out in the occlusal direction) and is lost. However, periodontal pus or abscess changes are acute and severe, leading to immediate extraction. Due to bacterial infection, the toxins degrade the body’s immune system and evade the tooth. However, besides these pathologies, there are some other factors for the progression of mobility. These include marginal inflammation due to excess accumulation of plaque. Some para-functional habits like bruxism (grinding of the teeth) also play an important role. They alter the tooth's functioning capacity by the application of excessive forces.
Often, there is excess tooth mobility due to occlusal prematurity, like defective occlusal function and altered tooth morphology. The presence of any abnormal shape (talon cusp), size (taurodontism), or dilacerations (abnormal curvature of tooth root) modifies occlusion by application of defective forces.
How to Diagnose Tooth Mobility?
Since dental mobility is a common symptom, the patient usually presents with excess movement (left, right, forward, inward, or sometimes combined. There is severe pain accompanied by bleeding (not common). In cases of avulsion, especially during accidents, extra-oral time of the tooth is very important, which is not more than 1 hour).
Investigations- X-rays, orthopantomogram, or radiovisiography are done to determine the amount of injury and nature of bone loss. Accordingly, the treatment options are presented for final success.
Tools to Check Mobility- Various methods have been used in the past to clinically check mobility. These include the application of various tools like mirrors and pointer-linked plasters with indicators. This apparatus, commonly called a periodontometer, is commonly used in some dental institutes today. Gauges comprised of resistant wire strains were also used to record the movement. With the advancement of time, cold-cure acrylics were also used to determine the impression of occlusion during mastication. In addition, electronic transducers were introduced to give more accuracy. The latest electronic method is the periotest,which contains electromagnets that percuss the periodontal ligament and measure the dampening of the associated ligament.
What Are the Treatment Options for Tooth Mobility?
The treatment for tooth mobility varies according to the etiology. For bruxism cases, occlusal guards are given, fixed or semi-fixed. Root canal treatment is immediately performed for immediate fracture or trauma to preserve pulp vitality. However, in the case of necrosis, apexification is performed. In addition to RCT, splinting is also performed. Splinting employs many methods, like the application of coaxial-braided wires (intracoronal) or ribbond splinting. The best and the most cost-effective treatment is Intra coronal splinting since it gives better strength and has fewer complications.
For pathologies, treatment involves selective grinding like coronoplasty, occlusal grinding, adjustments, and sometimes surgery with replacement by prosthesis like implants and fixed- partial-dentures
Conclusion
Mobility is difficult to handle since the golden hour of reporting (for vitality) is very low, and the patient usually reports after 48 to 72 hours. Hence, clinicians should make every effort to preserve the tooth and prevent it from mortality. Saving one tooth can prevent further teeth, thereby reducing excess load.
