Maxillary sinus augmentation by the crestal core elevation technique

A three-in-one alveolar process reconstruction protocol for maxillary molar sites with severe residual bone height deficiency: A proof-of-concept pilot study

BACKGROUND

Implant placement in maxillary molar sites with severe height deficiency often requires multiple surgeries, which was time-consuming, invasive, and subject to serious postoperative complications.

PURPOSE

To introduce and assess a three-in-one technique (extraction, alveolar ridge preservation [ARP], and sinus elevation) for augmenting deficiency maxillary molar alveolar ridges.

MATERIAL AND METHODS

Fourteen patients with severe posterior maxillary ridge height deficiency underwent extraction, sinus elevation via an intrasocket window and ARP using sticky bone and then covered with acellular dermal matrix (ADM). Primary closure was intentionally not obtained. Cone-beam computed tomography and periapical radiography were used to measure dimensional ridge changes over time. Bone biopsies were taken at implant placement 7-21 months after surgery, which proceeded without additional grafting. Peri-implant soft tissue was assessed after 8-12 months of functional loading.

RESULTS

Maxillary molar sites (13 first molars, 1 second molar) with a mean sinus floor height of 1.73 ± 0.86 mm and mean buccal plate thickness of 1.62 ± 1.15 mm were elevated and grafted. Immediately after surgery, the mean sinus floor height was 14.03 ± 1.97 mm and the alveolar thickness at virtual implant platform level was 12.99 ± 1.88 mm. After 5-9 months healing, those measurements decreased by 2.45 ± 1.73 mm (p = 0.000) and 3.88 ± 3.95 mm (p = 0.006), respectively. Healed ridges were composed of 18.74% ± 4.34% mean vital bone and 19.08% ± 9.10% mean residual graft. After 8-12 months of functional loading, the peri-implant tissue appeared healthy, and there was a mean marginal bone loss of 0.12 ± 0.11 mm.

CONCLUSIONS

For maxillary first molar sites with severe sinus floor height deficiency, this minimally invasive three-in-one treatment allows for uncomplicated implant placement and short-term functional stability.

Assessment of maxillary sinus lifting procedure in the presence of chronic sinusitis, a retrospective comparative study

INTRODUCTION

Chronic sinusitis can be considered a relative contraindication for sinus lifting procedure. However, its specific effects on bone height, infection and healing have not been as well investigated as its incidence as a post-operative complication.

METHODS

A retrospective comparative investigation was executed to evaluate the impact of chronic sinusitis on sinus lifting procedures regarding bone height, infection, and healing scores. Pre-operative and 6-month postoperative records (CBCT or CT and panoramic radiographs) of 40 patients who underwent sinus lifting procedure with graft and implant placement were split into two sets of 20 patients each; Group A is comprised of a patient with healthy sinus, whereas Group B includes patients with chronic sinusitis (identified as the presence of thickening of Schniederian membrane ≥ 2 mm, mucosal cyst, polyp or fluid level). Records of both groups were assessed for the difference in bone height of alveolar ridge between pre-operative radiograph and after six months postoperatively, and clinical notifications at the postoperative follow-up to report the healing and infection scores.

RESULTS

Statistically, there was non-significant difference in mean bone height gain (p-value > 0.05) in comparison to control group mean bone height (8.84 ± 0.93). Also, there was non-significant variation in mean healing and infection scores.

CONCLUSION

According to the available data, chronic sinusitis presenting as a thickening in the Schneiderian membrane has no significant effect on postoperative bone height, healing, or infection score in patients undergoing sinus augmentation with simultaneous implant placement. Further research is needed to better evaluate the effect of chronic sinusitis and its current status as a relative contraindication for sinus lifting procedure.

The impact of graft remodeling on peri-implant bone support at implants placed concomitantly with transcrestal sinus floor elevation: A multicenter, retrospective case series

OBJECTIVES

To evaluate the impact on peri-implant bone support (as assessed on periapical radiographs) of the remodeling dynamics of varying graft biomaterials used for transcrestal sinus floor elevation (tSFE).

METHODS

The study is a multicenter, retrospective series of cases undergone tSFE (performed according to the Smart Lift technique) and concomitant implant placement. At operator's discretion, tSFE was performed with bone core (BC) alone or supplemented by deproteinized bovine or porcine bone mineral (DBBM and DPBM, respectively), synthetic hydroxyapatite in a collagen matrix (S-HA), or ß-tricalcium phosphate (ß-TCP). Immediately after surgery, at 6-12 months post-surgery, and at later (≥24 months) follow-up intervals, the percentage proportion of the implant surface in direct contact with the radiopaque area was calculated for the entire implant surface (totCON%). Also, the height of the graft apical to the implant apex (aGH) was assessed.

RESULTS

At 6-12 months following tSFE, median totCON% was 100%, with a median aGH of 1.4 mm. A tendency of aGH to decrease in height was observed at later follow-up intervals for sites treated with all grafting procedures. In all treatment groups, the majority of the implant surface was still surrounded by the radiopaque area at the longest follow-up visits.

CONCLUSIONS

Although the height of the peri-implant radiopaque area apical to the implant apex tends to reduce overtime at sites which have received tSFE, the peri-implant bone support seems to be maintained long term irrespective of the graft material used.

Schematic of mean thickness distribution on the lateral aspect of the canine frontal sinus as an experimental model of sinus surgery

The dog frontal sinus may represent an alternative model dental implant research; its topographical resemblance to the maxillary sinus renders it a potentially favorable experimental environment. The aim of this study was thus to elucidate the anatomical configuration of the canine frontal sinus and histological characteristics, and to determine whether it could be a new canine experimental model for dental implant research. Twenty-four sides of canine frontal bones were harvested. The distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was measured with the aid of Lucion software. The thicknesses of the canine frontal sinus wall were measured, and the two specimens stained with hematoxylin and eosin. The mean distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was 16.0 mm. The mean thicknesses of the canine frontal bone at 3, 6, 9, 12, and 15 mm lateral to the midsagittal plane were 2.3, 2.7, 3.2, 3.8, and 3.7 mm, respectively. The canine frontal sinus was lined with pseudostratified ciliated columnar epithelium. These data suggest that the canine frontal sinus is a suitable alternative to the canine maxillary sinus as a model for studying various sinus augmentation protocols.

Lateral Bone Window Approach with Micross Mini Bone Scraper for Sinus Floor Elevation

Objective

The purpose of this article is to describe a technique with a mini bone scraper for lateral bone window approach and simultaneous bone harvesting during sinus floor elevation.

Methods

This study included five consecutive patients with the atrophic posterior maxilla. After elevation of mucoperiosteal flap, a bone window was then opened safely using a Micross Mini Bone Scraper^® with small shape and easy handling. Data were recorded on the residual alveolar bone height, number of implants, site of implant placement, collected particulate bone volume, and bone harvesting time.

Results

There was no injury of the Schneiderian membrane, and one to two implants of 11.5 mm length were placed simultaneously after sinus floor elevation in all cases. Mean residual bone height was 4.6 mm. The mean volume of particulate bone collected from the anterior wall of the maxilla using this technique was 0.74 cm³. Supplementary allogeneic materials were not required in all cases. Mean bone harvesting time was 4.6 min.

Conclusions

Our technique with Micross Mini Bone Scraper^® is a simple and safe procedure in lateral bone window approach and simultaneous bone harvesting during sinus floor elevation, because it is performed under better visualization of the membrane without irrigation.