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.