Morbidity after chin bone harvesting--a retrospective long-term follow-up study

Resorption of the alveolar bone after tooth extraction may result in insufficient bone volume for implant placement. Augmentation of the resorbed site using autogenous bone grafts harvested from the maxillofacial region, for example, the chin, is a common method; however, it also involves donor site morbidity. Chin graft morbidity involves impaired sensibility in the frontal teeth, the gingival, and skin postoperatively.

A group of 60 patients with partial edentulism in the maxilla and insufficient bone volume for implant therapy were augmented with bone grafts from the mandibular symphysis. The grafting procedure was performed between 1991 and 2001 with a follow-up period of 1 year after surgery. Postoperative sensibility of the lip, teeth, and gingiva was registered. Forty-six patients (18 women and 28 men) also participated in a long-term follow-up study. The mean age was 49 years (range 23-81 years) and the mean follow-up time was 7.5 years (range 4-14 years). The donor site was evaluated in four parts: a standardized clinical examination, radiographic examination and measurements, a mail-in questionnaire, and a survey of the medical records regarding complications and graft size. In the donor site, both hard tissue (mandibular symphysis and teeth) and soft tissue (ie, lower lip, infralabial area, and chin) were evaluated. A questionnaire was also answered by 38 of 46 patients.

In the long-term follow-up, impaired tactility and sensitivity of the soft tissues were registered in 7.6%. Adjacent teeth (incisors, canines, first and second premolar) (n = 418), showed increased lamina dura in seven cases (1.7%) and four teeth had apical pathology (1.0%). The donor site (n = 45) showed good remineralization in 42 patients (93.3%), and 28 patients (62.2%) had a noticeable concavity radiologically. The questionnaires from 38 patients (answer frequency 82.3%) rated high satisfaction with the grafting and implant treatment.

This study indicates that long-term follow-up of the chin graft donor site shows some postoperative morbidity. The most frequent disturbance was impaired sensibility in the soft tissues of the chin. The lower lip and teeth showed fewer disturbances. The rate of subjective symptoms was higher than the clinical findings but did, in general, not affect the patient in daily life. At radiographic examination, bone healing after chin graft harvesting did not regenerate to the preoperative level. The donor site showed good remineralization but left a radiologic concavity in the majority of cases.