4.1 Clinical assessment

Patients suffering from symptoms which relate to a third molar tooth may present to a General Dental Practitioner (GDP), a General Medical Practitioner (GMP), or to a hospital Accident & Emergency department.

Initial assessment should include a full medical and dental history, extra-oral and intra-oral clinical examination. Positive findings from this examination which suggest that treatment of the third molar or related structures may be indicated, require that a more detailed examination is carried out. This should determine whether removal is indicated and/or advisable (see sections 2 and 3), and should include radiological assessment.

Clinical assessment should be carried out with the aim of assessing the status of the third molars and excluding other causes of the symptoms. A complete examination should include assessment of: the eruption status of the third molar the presence of local infection caries in, or resorption of, the third molar and the adjacent tooth periodontal status orientation and relationship of the tooth to the inferior dental canal (IDC) occlusal relationship temporomandibular joint function regional lymph nodes. Any associated pathology should also be noted.

Radiological assessment is essential prior to surgery, but does not require to be carried out at the initial examination.

4.2 Radiological assessment

4.2.1 RADIOGRAPHIC EXAMINATION

Radiographic examination should provide the information necessary for adequate assessment of all third molar teeth.

Prior to the age of 13, radiographic examination is not normally indicated for the assessment of third molars⁶² and films taken from the age of 20 are most useful in assessing the likelihood of eruption.⁶³ When more than one third molar requires to be assessed, the radiographic examination of choice is a panoramic radiograph as the radiation dose of a panoramic radiograph is lower than from four periapical views and the diagnostic yield higher.^{62, 64, 65} Doses from panoramic radiography can be further limited by using field size limitation to prevent exposing areas not required in the field of view.⁶⁶ Periapical or oblique lateral radiographs may be taken as an alternative. All radiographs should be of a diagnostically acceptable standard.⁶⁷ Evidence level III and IV

As no large-scale study has demonstrated a sufficient incidence of pathological change associated with unerupted third molars, routine regular radiographic examination of unerupted third molars is not recommended.

4.2.2 RADIOLOGICAL EVALUATION

The purpose of a careful radiological evaluation is to complement the clinical examination by providing additional information about the third molar, the related teeth and anatomical features, and the surrounding bone. This is necessary in order to make a sound decision about the proposed surgical procedure, the most appropriate location for this to take place, and to highlight aspects of management which may require specific mention to the patient.

The following information should be noted in relation to upper and lower third molars: the type and orientation of impaction and the access to the tooth (The distinction between vertical and disto-angular orientation may affect the surgical approach, in particular with regard to the requirements for bone removal.) the crown size and condition the root number and morphology, including the presence of apical hooks (Identification of such hooks is important, as they may fracture during removal of the tooth and a decision is then required as to whether to attempt their removal: see section 5.3) the alveolar bone level, including the depth and the point of elevation and density the follicular width (There is no substantive evidence as to the dimension of follicular space which clearly indicates that cystic change has taken place.29, 42, 68, 69 Where doubt exists as to the likelihood of cystic change and there are no other positive indications for removal of the tooth, radiological review between six and 12 months is the recommended course of action.) the periodontal status, together with that of the adjacent tooth the relationship or proximity of upper third molars to the maxillary antrum and of lower third molars to the inferior dental canal.

The following signs have been demonstrated to be associated with a significantly increased risk of nerve injury during third molar surgery:²²

• diversion of the IDC
• darkening of the root where crossed by the canal
• interruption of the white lines of the canal.
  Evidence level III

In the presence of any of the above findings, great care should be taken in surgical exploration and the decision to treat carefully reviewed. The patient should be advised of the risk.

If on the initial panoramic radiograph there is a suggestion of a relationship between the roots of the lower third molar, and the IDC, a second radiograph should be taken70, 71 using different projection geometry.

4.3 Referral

Once it has been decided that a third molar should be removed, consideration should be given as to the appropriate treatment setting. GMPs are encouraged to refer to a GDP, although this does not preclude direct referral to a department of Oral and Maxillofacial Surgery or specialist practitioner.

The basis of this decision should take account of the general suitability of the facilities for operative procedures and recovery, the competence of support staff, and the training of the practitioner. In addition, each case should be assessed with regard to the patient's medical history and the expected degree of difficulty of surgical treatment (see section 5).

The referring clinician should provide information as to the clinical findings on presentation, medical history, and any radiographs pertinent to the case.

All preoperative radiographs should be transferred between clinicians concerned with the assessment and treatment of the patient. At the completion of treatment, radiographs should be returned to the originating clinician. The operating surgeon should retain a duplicate in situations where the level of morbidity raises, or may raise, concern.

The surgeon should by letter confirm receipt of the referral, and outline the treatment plan, specific information provided to the patient, the form of anaesthesia and what follow-up arrangements are required.

A discharge letter should always be sent to the referring clinician.