Does Timing of Secondary Alveolar Bone Grafting Affect the Need for Additional Bone Augmentation Prior to Implant...

The purpose of this study was to identify factors that influence the need for a supplemental bone graft prior to dental implant placement at previously grafted alveolar cleft sites.

Retrospective case series of patients with cleft lip/palate who had both alveolar bone grafting (ABG) and placement of a dental implant(s) to replace a missing incisor(s) at the cleft site by the senior surgeon (BLP) at Boston Children's Hospital from 2005 through 2020. Primary outcome variable was need for a supplemental bone graft prior to dental implant placement. Predictor variables included gender, cleft type (unilateral vs. bilateral), implant site, number of implants placed, age at ABG and implant placement, time between ABG and implant, history of maxillary expansion and whether the patient had a Le Fort I osteotomy to correct maxillary hypoplasia before implant placement. Descriptive statistics were computed and comparative analyses were performed using Pearson X², Fisher exact, and Mann-Whitney U tests.

There were 84 implants placed in 59 patients (64.2% female) with cleft lip and palate who had alveolar bone grafting of which 57.1% (n = 48) required a supplemental graft prior to placement. Median time (IQR) from alveolar bone grafting to implant placement was significantly longer in patients who required additional grafting (8.1 versus 5.4 years, P < .001). Patients who required supplemental bone were significantly younger at the time of alveolar bone grafting (10.1 versus 12.3 years, P < .001). Cleft sites in patients who had a Le Fort I osteotomy prior to implant placement required bony augmentation more often than cleft sites in patients who did not have a Le Fort I osteotomy (58.7% versus 33.3%, P = .03).

Patients with cleft lip and/or palate who undergo alveolar bone grafting should be counseled that they are likely to require a supplemental bone graft prior to implant placement.