Apicoectomy of an Endosseous Implant to Relieve Paresthesia: A Case Report

Apicoectomy of an Endosseous Implant to Relieve Paresthesia: A Case Report
September 2003
Levitt, David S. DDS* Private Practice, Lake Forest, CA.
Reprint requests and correspondence to: David S. Levitt, DDS, 22171 Crane Street, Lake Forest, CA 92630
Implant Dentistry: Volume 12(3) September 2003 pp 202-205
Please visit the web site to view the article in its entirety.
Abstract
Various radiographic and surgical techniques have been recommended to avoid paresthesia following mandibular implant placement. However, nerve impingement is sometimes inevitable, and when lingering numbness is reported, clinicians have a limited number of corrective options. This report describes a technique for cutting-back the apex of the implant, a technique that may be useful when lingering numbness persists after osseointegration has occurred.
The reported prevalence of long-term altered sensation of the mental nerve after mandibular implant placement is as high as 13%. 1,2 Various surgical and radiographic techniques have been utilized to avoid this complication. The radiographic methodologies range from simple to complex and include periapical and panoramic radiographs, tomography, and computed tomography. Sophisticated computer-aided measurement techniques may also be used, including barium-coated templates, computed tomography-generated templates, and three-dimensional reformatted images. 3,4 Unfortunately, even the best radiographs and computer enhancement do not always clearly show the location of the canal. Schropp et al 5 reported that even with tomographic techniques, the discrepancy between the implant sizes that were radiographically selected and those actually placed was 13% in a group of experienced implant surgeons. Surgical exposure of the mental foramen to allow direct visualization and measurement is sometimes recommended. Unfortunately, the distance from the alveolar crest to the inferior alveolar canal is not always identical to the depth of the foramen. 6,7 Some graduate-training programs even recommend the use of infiltration rather than block anesthesia so that patient discomfort may serve as a guide to canal location. However, this method is not always satisfactory because bone has sensory nerve endings, 8 making the procedure intolerable to many patients. Finally, nerve lateralization may be done before implant placement in those cases where bone height is clearly inadequate. This procedure carries its own significant risk of paresthesia. 9
It is imperative that the practitioner use as many methods as seems necessary to avoid nerve involvement in any particular case. Because none of the methods is perfect, it follows that a significant potential for violation of the canal may still exist. A postoperative radiograph and instructions to the patient to report any lingering numbness are prudent cautions. If nerve impingement is suspected, the choices include removal of the implant, reverse torquing of the implant by several turns to move the apex away from the nerve, or no treatment. The first two procedures must be accomplished during the healing phase, before the implant has integrated with the bone. This article describes an additional option that may be used after osseointegration has occurred: apicoectomy of the implant.