Efficacy of panoramic radiographs in the preoperative planning of posterior mandibular implants: a prospective clinical study of 1527 consecutively treated patients.
OBJECTIVE
Various imaging techniques, including conventional radiography and computed tomography, are proposed to localize the mandibular canal prior to implant surgery. The aim of this study is to determine the incidence of altered mental nerve sensation after implant placement in the posterior segment of the mandible when a panoramic radiograph is the only preoperative imaging technique used.


METHODS
The study included 1527 partially and totally edentulous patients who had consecutively received 2584 implants in the posterior segment of the mandible. Preoperative bone height was evaluated from the top of the alveolar crest to the superior border of the mandibular canal on a standard panoramic radiograph. A graduated implant scale from the implant manufacturer was used and 2 mm were subtracted as a safety margin to determine the length of the implant to be inserted.


RESULTS
No permanent sensory disturbances of the inferior alveolar nerve were observed. There were two cases of postoperative paresthesia, representing 2/2584 (0.08%) of implants inserted in the posterior segment of the mandible or 2/1527 (0.13%) of patients. These sensory disturbances were minor, lasted for 3 and 6 weeks and resolved spontaneously.


CONCLUSIONS
Panoramic examination can be considered a safe preoperative evaluation procedure for routine posterior mandibular implant placement. Panoramic radiography is a quick, simple, low-cost and low-dose presurgical diagnostic tool. When a safety margin of at least 2 mm above the mandibular canal is respected, panoramic radiography appears to be sufficient to evaluate available bone height prior to insertion of posterior mandibular implants; cross-sectional imaging techniques may not be necessary.
Vazquez
Lydia
L
Department of Oral Surgery, Oral Medicine, Oral and Maxillofacial Radiology, School of Dental Medicine, University of Geneva, Geneva, Switzerland. lydia.vazquez@medecine.unige.ch
Saulacic
Nikola
N
Belser
Urs
U
Bernard
Jean-Pierre
JP
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001641:Bicuspid; D020209:Cranial Nerve Injuries / Q000209:etiology*; D003758:Dental Implantation, Endosseous / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging* / Q000534:rehabilitation; D008297:Male; D008334:Mandible / Q000601:surgery; D008875:Middle Aged; D008953:Models, Anatomic; D008963:Molar; D010292:Paresthesia / Q000209:etiology; D010347:Patient Care Planning; D011446:Prospective Studies; D011858:Radiographic Magnification / Q000009:adverse effects; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic / Q000706:statistics & numerical data*; D061221:Trigeminal Nerve Injuries