Management of mobile teeth

Tooth mobility can arise from physiological and/or pathological movement. A degree of physiological movement of teeth in health is derived from the associated periodontal ligament (PDL) attachment.¹ Pathological tooth mobility is considered to be displacement of a tooth in a horizontal or vertical direction beyond the physiological limit.²

Tooth mobility carries several implications: reduced function to the patient; compromised anaesthetics; occlusal instability; difficulty with cleaning the tooth resulting in plaque accumulation;³ and discomfort, all of which contribute to a reduced quality of life.⁴ The rationale for addressing tooth mobility is to generate a positive impact on patient health.

There are several important factors that may influence tooth mobility. In the absence of inflammation, the factors that determine tooth mobility are predominately the total length of periodontal ligament support together with its width.² Factors that increase the risk of a tooth becoming mobile include the number and distribution of the remaining teeth, the anatomy and health of the tooth (number of roots, root form and shape, previous root amputation, root proximity and attachment level), as well as occlusion.⁶

There are many indexes available to assess tooth mobility, with the most widely used being Miller's tooth mobility index,⁷ which assesses tooth mobility through observing or feeling any movement of the tooth when subjected to palpable or occlusal forces. This is undertaken by holding the tooth between two dental instruments, or one finger and a dental instrument and then attempting to move the tooth in horizontal or vertical directions.⁴ Alternative approaches include electronic devices and digital approaches (such as intra-oral scanners).⁹

Aetiology/causes

There are several underlying factors that contribute to tooth mobility, which are important to identify as part of management. Common causes are outlined below.

Periodontitis

Periodontitis is a chronic inflammatory condition that results in the destruction of the soft and hard tissues that support a tooth, tooth mobility and ultimately, tooth loss.¹⁰ Tooth mobility is one of the most common signs and/or symptoms with which a patient with periodontitis may present. Therefore, assessing tooth mobility is key to identifying such a patient.¹¹

Tooth mobility as a result of periodontitis can be identified clinically by tooth mobility, drifting/migration of tooth, extrusion of teeth, presence of periodontal attachment loss (deep periodontal pocketing, inflammation and/or recession). Radiographically, this can be confirmed and further evaluated by identifying loss of bone around the tooth and periodontal ligament widening.¹⁰

Occlusal trauma

Occlusal trauma arises from functional or parafunctional forces resulting in injurious tissue changes to the attachment apparatus (periodontal ligament, supporting alveolar bone and cementum).¹² This can be further categorized as primary or secondary occlusal trauma.

Primary occlusal trauma occurs when tissue changes arise from excessive occlusal forces on teeth with a normal periodontal support,⁸ whereas secondary occlusal trauma is defined as injury resulting in tissue changes from normal or excessive occlusal forces on teeth with a reduced periodontal support.⁸

Occlusal trauma would ideally be diagnosed through histology, but as this is not possible with a patient, clinical and radiological presentations are used.

Clinically, signs of occlusal trauma can present from the patient as pain or discomfort during or after mastication, mobile teeth, fremitus, occlusal discrepancies/disharmonies, wear facets, drifting or migration of teeth, thermal sensitivity, high restoration or a fractured tooth.¹³ Radiographically, this may present as widening of the periodontal ligament, root resorption, cemental tears and bone loss.⁸

Trauma (general)

Traumatic injury to the dentition can result in luxation and avulsion, as well as root fractures of the teeth. Patients with dental trauma often present with mobile teeth, so it is important to identify this cause of mobility, as well as assess for any other injuries that may have also occurred.^14,15

Clinically, the patient may present with: tooth mobility as well as pain, tenderness to percussion, bleeding from the gingival sulcus, displacement of the teeth, change in percussion sound and soft tissue injuries.¹⁴

Radiographically, a fracture may sometimes be identified along with change in PDL space (widening or loss of space), peri-apical pathology or displacement of the tooth.¹⁴

The clinical and radiographic presentations of the teeth vary depending on the type of injury and often require splinting as a temporary measure, which also allowa for monitoring of healing.^14,15

Orthodontics

Orthodontic therapy involves movement of the teeth, which can result in mobility of the teeth during the process. However, in the healthy periodontium, once the teeth have been orthodontically moved and the forces released, tooth mobility decreases.^16,17 The timing of applying orthodontic treatment on patients treated for periodontitis has been debated within the literature. Zasčiurinskienė et al demonstrated no difference in attachment levels when undertaking orthodontic therapy immediately after periodontal therapy in comparison to waiting 3–6 months after periodontal therapy.¹⁸

However, it is imperative to ensure that good plaque control is maintained.¹⁹ If good plaque control is not maintained during orthodontic therapy, the risk of inflammation and exacerbation of bone loss can lead to increased mobility and tooth loss.²⁰

Pathology

Tooth mobility may be related to an underlying pathology, which although not the most common cause, is imperative to diagnose early. These can involve peri-apical endodontic lesions, cystic lesions²¹ and rarely, malignancies.²²

In such cases, a full patient history to evaluate symptoms, with a full clinical assessment to identify signs (including lymph node palpation of the neck and thorough examination of intra-oral soft tissues) are important to rule out any of the above causes. Special investigations, such as radiographs, should also be considered to confirm pathology.²²

Referral to secondary care should be considered for further clinical investigation which may include radiographic, microbiological and pathological evaluation.²³

Management

The priority for management of mobile tooth is to definitively diagnose the underlying cause and to establish the prognosis of the mobile tooth.⁶

Teeth with an unfavourable prognosis owing to severe attachment loss require extraction. Where the prognosis is better, other treatment modalities can be explored. Asymptomatic mobile teeth presenting with a healthy connective tissue attachment and in the absence of inflammation, may require no further intervention.²⁴ In such cases, it is important to record the tooth mobility grade and monitor this status at follow-up. Monitoring tooth mobility may similarly be appropriate for a patient undergoing orthodontic therapy because mobility should reduce on completion of treatment.¹⁶

Patients who present with mobility ascribed to unstable periodontitis should receive appropriate intervention derived from the S3-level guidelines of the British Society of Periodontology.²⁵ This involves oral hygiene advice, supragingival professional mechanical plaque control (PMPR) and further subgingival PMPR, if appropriate. For some, periodontal surgery may also be indicated to obtain periodontal disease stability. This can allow for healing and therefore tightening/prevention of worsening of the mobile tooth. However, if the tooth becomes progressively more mobile and symptomatic, further treatment may be indicated, such as occlusal adjustment or splinting of the tooth.²⁶

Once the conditional prerequisite of periodontal stability is achieved and occlusal adjustment completed, splinting of teeth may be undertaken.⁴ The significant and beneficial outcomes of splinting a mobile tooth allow the forces applied to that tooth to be distributed to adjacent teeth,²⁷ which reduces trauma to the mobile tooth, provides comfort during function, reduces the mobility, protects the pulp and prevents further tooth drifting.²⁸ However, studies have shown that splinting teeth may not improve the survival of mobile teeth with advanced periodontitis.²⁹ Splints can either be removable (night guards) or fixed. Fixed splints include ligature wires, fibre-reinforced resin or fixed orthodontic retainers. The splint construction material may be metal (stainless steel, cobalt, chrome and cast metals), non-metal (acrylic and composite resins) or a combination of metal and non-metal. Splints may also be defined as being extra-coronal (stabilizing wires, fibre-reinforced ribbon, fixed orthodontic retainer, night guard) or intra-coronal (inlays and nylon wire) depending on positioning.³⁰ The duration for which the splints remain in the mouth may be provisional, short or long term.³¹

The indications for placing a splint include the following:

• A reduced periodontium where the mobile tooth is:
• Causing the patient discomfort
• To restore the patient's psychological and physical wellbeing;³⁰
• Aid non-surgical subgingival PMPR in a periodontitis patient (temporarily);³²
• Stabilization of mobile teeth during periodontal surgery to aid post-surgical periodontal healing, e.g. during periodontal regenerative surgery;³³
• To maintain a previously migrated tooth that is repositioned;³⁶
• Post trauma (avulsion, luxation injuries or root fractures);^14,15
• Orthodontic treatment (anchorage during treatment or fixed orthodontic retainer post treatment);¹⁶
• Diagnostic purposes, e.g. temporomandibular dysfunction, TMD.³⁴

Splints compromise plaque control, therefore periodontal management with well-defined therapeutic outcomes and caries assessment should be undertaken prior to splint placement, with careful monitoring thereafter. Splints may result in suboptimal periodontal or occlusal conditions, with further disadvantages being interference with speech and the risk of the splint fracturing. Some of the contraindications to placing a splint are:²⁶

• Patients where providing a splint will not result in occlusal stability;
• Patients with poor oral hygiene;
• Insufficient support of adjacent teeth to adequately stabilize the mobile tooth;
• Presence of an occlusal interference;
• High risk of caries;
• Severe misaligned/crowding of teeth that would compromise the success of the splint.

Splints should be placed so that the forces are directed along the long axis of the tooth. Ideally teeth should be splinted to those with the greatest periodontal support, should not interfere with the occlusion or irritate the soft tissues (gingiva, cheeks, tongue and lips). The splint design should be cleansable for the patient and should avoid blocking the interdental embrasure spaces.³⁰

Occlusal adjustment to selectively reshape the occlusal surface to create a harmonious contact between the opposing teeth may be considered for teeth that have an occlusal interference resulting in increasing tooth mobility or fremitus, discomfort to the patient during occlusal contact, contributing to soft tissue injury or food impaction. The aim would be to establish light occlusal contacts in the intercuspal position (ICP) with no contact points in excursion and non-working side interferences. This would allow for a stable occlusal relationship.⁶

The contraindications for occlusal adjustment include prophylactic treatment with no signs or symptoms of occlusal trauma, severe mispositioning and mobility of the tooth and as the primary treatment for periodontitis. For some patients, a combination of treatment methods may be required, starting with most conservative options first. A typical example would begin with periodontal non-surgical therapy followed by re-assessment.⁶

Conclusion

Teeth that have extensive attachment loss should be considered for extraction.²⁴ It is, therefore, important to assess whether the mobility is symptomatic for the patient and the prognosis of the tooth. Managing mobile teeth is complex and should be treated with a step-by-step approach. Splinting teeth does not address or eliminate the cause of tooth mobility, but does support periodontal therapy by providing stability and comfort to the patient.³⁰ Furthermore, tooth mobility alone is not an indication of a pathological condition, or an indication that splinting of the teeth is required.

Splinting of mobile teeth is often used in periodontal supportive care, where the disease is stable, but some mobile teeth are causing discomfort for the patient.³⁵

Overall, it is important to identify the underlying cause, which once treated, should enable the introduction of splinting as an appropriate treatment option. Splinting is not a substitute for inappropriate or unsuccessful periodontal interventions.³⁰