Radiological sinus lift: a new minimally invasive CT-guided procedure for maxillary sinus floor elevation in implant dentistry

Crestal sinus augmentation in a head back position: Retrospective case series

Objectives

To evaluate the clinical efficacy of Crestal Sinus Augmentation (CSA) in a head back position (CSA-HBP) for maxillary sinus mucosa elevation.

Materials and Methods

We enrolled 209 patients, 246 maxillary sinuses, 348 sites in this study. Complications, maxillary sinus mucosal perforation rate and cumulative survival rate (CSR) data were collected to evaluate the clinical efficacy of CSA-HBP. Maxillary sinus mucosal elevation height (EH) and new bone height (NH) were measured by cone-beam computerized tomography and standard periapical radiographs. The implantation sites of residual bone height (RBH) ≤5 mm and RBH >5 mm were marked as Groups A (n = 81) and B (n = 267), respectively. The implantation sites of the second and third molar sites were marked as Group C (n = 134), and the remaining sites were marked as Group D (n = 214).

Results

The RBH before implant placement was 6.63 ± 2.10 mm (95% confidence interval [CI] 6.41- 6.85 mm). The mucosal EH was 4.04 ± 1.86 mm (95% CI 3.85 - 4.24 mm). The NH was 2.36 ± 1.20 mm (95% CI 3.85-4.24 mm). No other complications were found except three cases of postoperative swelling and one case of nasal blood secretions. The overall mucosal perforation rate was 1.44% (5/348, 95% CI 0.2%-2.7%) and the rate of RBH ≤ 5 mm (Group A) was 1.49% (2/134, 95% CI 0%-3.50%). The 8-year CSR was 99.71% (347/348, 95% CI 99.2%-100.0%). Mucosal EH and NH were higher in RBH ≤5 mm (Group A) than in RBH >5 mm (Group B) (P = 0.001 and P = 0.001, Mann-Whitney U-test). There were no significant differences in mucosal EH and perforation rate between second and third molar sites (Group C) and other sites (Group D) (P = 0.77, Mann-Whitney U-test, and P = 0.16, Yates' Chi-square independence test).

Conclusions

CSA-HBP is a minimally invasive and reliable technique.

Shape-Memory ECM-Mimicking Heparin-Modified Nanofibrous Gelatin Scaffold for Enhanced Bone Regeneration in Sinus Augmentation

Biomaterials with clinical maneuverability and predictable bone regeneration are needed in the field of maxillary sinus augmentation. Herein, gelatin was chemically modified with heparin that specifically interacted with and stabilized bone morphogenetic protein-2 (BMP-2). We then introduced thermally induced phase separation to form the injectable, shape-memory, highly porous scaffold for bone regeneration in sinus augmentation. The hydrated heparin-modified nanofibrous gelatin scaffolds (NH-GS) were demonstrated with high resilience and shape-memory property, both macroscopically and microscopically, making them injectable scaffolds and expected to be applied in sinus augmentation. This novel scaffold was verified to be biocompatible and an excellent matrix to support cell attachment, proliferation, and infiltration. Further, the growth factor-loaded NH-GS showed sustained release kinetics of BMP-2 through affinity-based scaffold-growth factor interaction, compared with BMP-2 loaded gelatin sponge (GS) and nanofibrous gelatin scaffold (NF). Both in vitro and in vivo experiments demonstrated that the BMP-2-loaded NH-GS exhibited the highest osteogenesis among the other groups. Taken together, this study introduces a new regenerative strategy in maxillary sinus augmentation, which is injectable with a predefined shape and structure and promotes bone regeneration through a more sustained BMP-2 release.

Microscope and micro-camera assessment of Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study

OBJECTIVE

We sought to assess the effectiveness of using a microscope and non-invasive camera for assessing sinus membrane perforations during transcrestal sinus floor elevation (TSFE).

MATERIALS AND METHODS

Five fresh human cadaver heads corresponding to eight maxillary sinuses (six bilateral and two unilateral) underwent 4 TSFEs per sinus (a total of 32 single site elevations). Each elevation was randomly assigned to receive a three or six mm membrane elevation height (MEH). A microscope and micro-camera were used to assess the sinus membrane perforation. Afterwards, radiological and clinical membrane perforation assessments were performed. The statistical analysis results are expressed using the means, standard deviations, range values of the residual ridge height (RRH), residual ridge width (RRW), sinus membrane thickness (SMT) and incidence of perforation (IoP). Generalized linear methods were used to test for the correlation of RRH and MEH to the microscope and micro-camera perforation assessments and the correlation of microscope and micro-camera assessments with the post-operative CBCT and crestal liquid evaluation.

RESULTS

The cumulative percentage of IoP was 40.62%, (23.07% with 3 mm MEH, and 76.92% with 6 mm MEH, p < 0.05). The perforation assessed using either the microscope or micro-camera coincided with the post-operative CBCT and crestal liquid assessment in 87.55% sites. No significant correlation was found between the microscope or micro-camera assessments with RRH or MEH.

CONCLUSION

Application of a microscope and micro-camera during transcrestal sinus floor elevation may allow the detection of the integrity of the Schneiderian membrane with greater than 85% accuracy in this ex vivo model.