Immediate and delayed lateral ridge expansion technique in the atrophic posterior mandibular ridge

Purpose: The lateral ridge expansion technique is used to expand the narrow edentulous ridge for implant placement. The staged approach can be used to split the mandibular ridge to decrease the risk of malfracture during osteotomy. The present study reports the clinical results of a surgical technique that expands a narrow mandibular ridge using an immediate and a delayed lateral expansion technique. Materials and Methods: A total of 32 patients with a narrow edentulous posterior mandibular ridge of 2 to 4 mm were included in the present study, and 84 implants were placed. Of the 32 patients, 23 were treated with an immediate lateral expansion technique and 9 with a delayed lateral expansion technique. Results: Of the 23 patients who underwent the immediate lateral expansion technique, a malfracture of the thin buccal cortical plate occurred during ridge splitting in 5 patients. All buccal segments of the 9 patients who underwent the delayed lateral expansion technique fractured as planned at the inferior horizontal corticotomy line favorably. After 4 to 5 months, all implants were stable and surrounded by bone, and ossification of the osteotomy line was obvious. Conclusions: The lateral ridge expansion technique is effective for horizontal augmentation in the severely atrophic posterior mandibular ridge. The delayed lateral ridge expansion technique can be used more safely and predictably in patients with high bone quality and thick cortex and a narrower ridge in the mandible.