Management of Impacted Teeth
To discuss the assessment and describe the surgical management of impacted teeth.
After reading this chapter, you should have an understanding of the assessment of impacted teeth, and how such teeth should be managed.
Impacted teeth are frequently found during routine clinical and radiographic examination. Once discovered, the clinician has to decide whether or not the tooth should be removed. Once the decision to remove the tooth has been made, the method of anaesthesia and surgical technique should be selected. This has to be done with an appreciation of the potential surgical complications.
Impaction occurs when there is prevention of complete eruption into a normal functional position within the dental arch, caused by obstruction by another tooth, or development of the tooth in an abnormal position.
The tooth most commonly impacted is the mandibular third molar, with the maxillary canine the second most frequently impacted tooth with a prevalence of 1.7%.
Once an impacted tooth has been discovered, its position relative to the surrounding structures needs be assessed. This is usually done radiographically (Fig 6-1). Once the position of the tooth has been established, the clinician has to decide what to do about it.
The decision to remove a symptomatic tooth is usually straightforward. This is guided by the need to relieve the patient’s symptoms, such as pain or infection. The difficulty arises with asymptomatic impacted teeth found during routine clinical examination or, more frequently, by radiographic examination (Fig 6-2).
There are a number of treatment options. The tooth can be left alone with periodic assessment; it can be surgically removed, or surgically exposed to encourage spontaneous eruption or facilitate orthodontic alignment. A further option of tooth transplantation may also be considered in certain circumstances (see Chapter 8).
Foremost in the decision-making process should be the wish of the patient, who must make the final decision. This judgment will normally be based on guidance given by the clinician. This should include indications for and against any proposed treatment. The different options are described below.
Doing nothing is a decision that often finds great favour with the patient. Although there may be no indication to remove the impacted tooth at that point in time, the patient should be made aware of any potential future complications that the impacted tooth may cause, when left untreated. Tooth movement, resorption of adjacent teeth and cyst formation are the main risks (Figs 6-3 and 6-4).
An impacted tooth that does not warrant treatment should be monitored periodically by both clinical and radiographic examination. This is to detect any change in position or a developing local pathology.
There are a number of indications for the surgical removal of an impacted tooth. Clinical guidelines such as those produced by the UK National Institute for Clinical Excellence (NICE) are useful in this regard. The indications for surgery are described overleaf.
When there is a history of infection, in particular recurrent infection, this is usually localised – such as pericoronitis, which is the commonest reason for the removal of impacted third molars (Fig 6-5). Cellulitis or abscess formation can also occur in relation to impacted teeth (Fig 6-6).
The impacted tooth should be removed when it is carious, or when it is the cause of caries in an adjacent tooth (Fig 6-7).
The presence of pulpal and/or periapical pathology is an indication for removal of an impacted tooth.
Periodontal disease, in particular when associated with an adjacent tooth, can often be arrested by removing the impacted tooth.
When an impacted tooth has developed internal or external resorption, or there is resorption of an adjacent tooth (Fig 6-3), it should be removed. This can be a major problem in adolescent patients, in whom root resorption of the incisor teeth can be expected in about 12.5% of incisors adjacent to an ectopic canine (Figs 6-8 to 6-9).
Impacted teeth should be removed if they are the cause of, or are associated with, pathology. Examples include disease of the follicle associated with the crown of an unerupted impacted tooth. This may be a cyst or tumour.
When an impacted tooth is lying in the line of a fracture it may be removed if it interferes with fracture reduction. This is often the case with impacted mandibular third molar teeth (Fig 6-10).
Removal of an impacted tooth may be indicated to allow:
the orthodontic alignment of the adjacent teeth
orthognathic or reconstructive surgery of the jaws. Impacted mandibular third molars are often removed around nine months prior to a sagittal splint mandibular osteotomy to facilitate surgery and reduce morbidity
restorative treatments such as the placement of a fixed prosthesis o/>