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Risk assessment of M3Ms and decisions on ordering a CBCT and prescribing a coronectomy Tara Renton Dental Update 2024 44:10, 707-709.
Authors
TaraRenton
BDS, MDSc, PhD
Professor of Oral Surgery, King's College London; Honorary Consultant in Oral Surgery, King's College Hospital NHS Foundation Trust and Guy's and St Thomas' NHS Foundation Trust, London
Coronectomy is a procedure that is evidence based in order to prevent inferior alveolar nerve injury (IANI) related to surgery for high risk mandibular third molars (M3Ms). The justification for undertaking coronectomy rather than third molar removal is based upon risk assessment of the M3M, for which one has no clear parameters. There is international acceptance of this technique, however, there are many outstanding issues relating to the criteria for prescription, investigation and decision-making for this procedure including: risk factors for IAN injury/indications for cone beam CT scan (CBCT); indications for coronectomy as seen on plain films and then on to CBCT; complications/contra-indications of coronectomy; legal issues; and recommendations.
Thus this personal opinion paper was aimed at highlighting the complexities around investigating, prescribing, patient consent and undertaking coronectomies, in order to assist the clinician in making surgical decisions faced with an ever changing evidence base and lack of specific criteria.
CPD/Clinical Relevance: Third molar surgery is one of the most common surgical procedures undertaken on the NHS. Up to 48% of patients are reported to be at higher risk of inferior alveolar nerve injury after assessment with dental pantomograms, but the numbers do vary depending upon the patient cohort. This paper aims to unravel some of the conflicting evidence and attempts to provide some useful practical tips on the optimal management of these patients.
Article
Mandibular third molar (M3M) extractions are the most often performed procedures in the field of oral surgery.1 M3M is a challenging surgical procedure due to close proximity to anatomical structures such as the IAN and lingual nerves. Inferior alveolar nerve injury (IANI) is avoidable and should be prevented where possible as trigeminal sensory neuropathies result in long-term chronic pain and disability for 70% of patients affected.2
Coronectomy (partial tooth removal, deliberate vital root retention and partial odontectomy) has become a routine oral surgical procedure with the aim to minimize risk of IANI in relation to the removal of high-risk M3Ms. Coronectomy, a coded surgical procedure both in US (OMFS Category service 2 D7251) and Japan, has been defined as a method of removing the crown of a tooth but leaving the roots untouched, which may be intimately related with the IAN, so that the possibility of nerve injury is reduced. At the inception of this technique, questions were raised3 and, despite its increasing popularity and acceptance, many concerns remain
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