Direct v/s Indirect sinus lift in maxillary dental implants

Lack of sufficient bone height along maxillary sinus poses significant difficulty for placement of implants in edentulous maxillary jaw. Minimally invasive sinus augmentation is an effective solution for this problem. The manuscript intends to present long period results of such augmentation using direct (DSAT) and indirect (ISAT) minimally invasive sinus augmentation technique (SAT) from a single center.

Records of patients who required minimally invasive sinus augmentation to increase residual bone height for implant placement fulfilling predetermined exclusion and inclusion criteria. Only patients with follow-up records for at least a year were considered. Both DSAT and ISAT were employed for sinus augmentation. The age, gender, period of edentulousness, alveolus thickness at crestal level during the pre- and postoperative assessment, implant length, and diameter of implants were collected from case histories. Descriptive statistics, Chi-square, paired test, and one way analysis of variance (ANOVA) was used appropriately. P ≤ 0.05 was considered as significant.

There were 197 implants placed and mean age of the group was 40.2 ± 10.7 years. There was a slight male predilection (54.3%). The gain in bone height as expressed in percentage after a year was 134.6%. On comparing the length of residual alveolar bone (RAB) at start and end of study, ISAT had a mean preoperative height of 7.88 mm while postoperative height was 13.22 mm. For DSAT, the mean height at start of treatment was 3.94 mm while at the end it was 10.13 mm. The mean increase in height was 6.19 mm. For both cases, P was 0.000.

Age, gender, and period of edentulism did not influence the outcome. The alveolar width appears to differ and influence the outcome. When alveolar width increases, wider diameter implants can be placed by compromising height. Thus it is a clinical acumen that would be extremely helpful to gauge the outcome of the condition.