Cone Beam Computed Tomographic Analysis Demonstrates a 94% Radiographic Success Rate in 783 Alveolar Bone Grafts.

Purpose: Success of alveolar bone grafting has been estimated using 2-dimensional periapical radiographs that are associated with image distortion. Cone beam computed tomography (CBCT) accurately displays 3-dimensional anatomy. This study sought to develop and apply a radiographic measure of alveolar bone grafting success using CBCT.

Methods: This was a retrospective case series composed of patients with cleft lip/palate who had iliac crest bone grafting by 1 surgeon from 2005 to 2020. CBCT scans were obtained ≥4 months after graft. The outcome variables included vertical bone height on cleft adjacent teeth, labiopalatal thickness, and nasal floor symmetry and were scored using a 1 to 4 ordinal scale. Vertical height was determined by the distance from the cementoenamel junction to the marginal bone level of cleft adjacent teeth (1: ≥75% root length, 2: ≥50 to <75%, 3: ≥25 to <50%, 4: <25%), labiopalatal thickness was scored by comparing graft thickness with root width of cleft adjacent teeth (1: <50%, 2: ≥50, 3: ≥75%, 4: ≥100%), and piriform symmetry was established by comparing the nasal floor height between sides (1: ≥6 mm, 2: ≥3 and < 6 mm, 3: ≥1 and < 3 mm, 4: a score of ≥3 < 1 mm). To be considered a successful graft, each dimension scored ≥3. Grafts were also successful if piriform symmetry scored 2, when all other measures indicated success.

Results: The sample was composed of 618 patients with 783 alveolar cleft sites. Subjects' median age was 10.0 (interquartile range 1.6 years), and 59% were male. CBCT scans were obtained a median of 9.7 months (interquartile range 68.8 months) after grafting. There was good-to-excellent intrarater and inter-rater agreement for measurements. Alveolar bone grafting was radiographically successful in 94% of patients.

Conclusions: This is a valid and reliable assessment tool, and when applied to a large cohort, it demonstrated a 94% graft success rate. Future studies will identify predictor variables associated with bone graft outcomes.