Morbidity of harvesting of chin grafts: a prospective study

In a prospective study, 20 patients who underwent harvesting of chin grafts as outpatients, were followed up for 12 months (3 further patients with in complete followup data were excluded from the study). Preoperatively and 7 days, 1, 3, 6 and 12 months postoperatively, follow-up data were assessed. Evaluation of the superficial sensory function of the inferior alveolar ner ve was determined by the Pointed-Blunt Test and the Two-Point-Discriminatio n Test. Sensory disturbances were objectively assessed by testing thermal s ensitivity with the "Pain and Thermal Sensitivity" Test (PATH Test). In add ition, evaluation of the pulp sensitivity of teeth 35-45 was carried out by cold vitality testing. One week postoperatively, 8 patients were affected by superficial sensory impairment. 8 nerve territories showed hypoaesthetic reactions and 5 showed hyperaesthetic reactions. After 12 months, two pati ents still suffered from hypoaesthesia of one side of the chin. There was a statistically significant sensitivity impairment of the chin for all patie nts comparing the preoperative data of the Two-Point-Discrimination Test (l eft/right median: 8.17/8.17 mm, interquartile range (IQR) 1.00/2.00 mm) wit h the first postoperative measurement (left/right median 9.00/8.33 mm, IQR 1.67/2.66 mm). Comparing the latter to the last postoperative measurement t here was significant tendency for regeneration of a nerve function (left/ri ght median 8.00/7.84 mm, IQR 0.66/2.00 mm). In the PATH Test all hypoaesthe tic areas could be identified by a reduction of thermal sensitivity. After the first postoperative examination 21.6% (n=38/176) of the examined teeth had lost their pulp sensitivity. After 12 postoperative months 11.4% (n=20/ 176) still did not react sensitively. Many of these were canines (n=8/20). Comparing the preoperative to the first postoperative examination, there wa s a significant reduction of pulp sensitivity. However, statistically signi ficant recovery until the last postoperative follow-up could not be detecte d. The assessed data show that patients have to be informed extensively abo ut disturbances of the inferior alveolar nerve function lasting longer than 12 months. Moreover, the loss of pulp sensitivity is a very frequent event which has always to be taken into account. Considering the high rate of co mplications with harvesting of chin grafts, more prospective trials should be done to find out whether there are other donor sites for autogenous bone which put less strain on patients.