Measuring the outcomes of lateral ridge augmentation using cone-beam computed tomography

Objectives

Lateral ridge augmentation (LRA) is a surgical technique to gain bone prior to implant placement. Performing cone-beam computed tomography (CBCT) pre- and post-surgery allows for quantitative comparison of the buccal–lingual width and the vertical height of the edentulous ridges. This study used CBCT images to evaluate the bone regeneration following surgery.

Methods

A total of 30 cases from adult patients who underwent LRA and had high-quality CBCT images taken pre- and post-surgery from the same CBCT scanner were available for the retrospective study. Study data included linear measurements of the bone ridge width and height obtained from the middle of the edentulous ridge and a volumetric measurement of bone growth at the edentulous site observed on the CBCT scan.

Results

The reliability of the measurements was excellent as indicated by Intra-Class Coefficient values of 0.974 or higher. There was a significant mean bone increase from pre-surgery compared to post-surgery for both the linear and volumetric measurements. The linear bone gain ranged from 1.5 to 2.5 mm and volumetric gain from 250 to 750 mm³. However, two patients did not gain any bone. Multivariate regression showed the strongest predictors of bone gain post-surgery were the pre-surgery bone volume and a surgical site being in the mandible. For maxillary surgical sites, particularly anterior areas, the LRA surgeries were the least successful.

Conclusions

LRA before implant placement helped to increase bone for the majority of patients, particularly for surgical sites in the mandible. The quantitative analyses in the CBCT images showed excellent intra-examiner agreement.