Sinus Mucosa Thickness Changes and Ostium Involvement after Maxillary Sinus Floor Elevation in Sinus with Septa. A Cone Beam Computed Tomography Study

Research trends on maxillary sinus septa in 2019-2021: a scoping review with scientometric analysis

PURPOSE

This study aimed to conduct a bibliometric analysis of trends in the description items within the literature published from 2019 to 2021 with "maxillary sinus septum" in the title or subtitle.

METHODS

Electronic data from PubMed (MEDLINE), Google Scholar, and ScienceDirect were searched from 2019 to 2021. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) to select 21 of 243 articles and examined their studies. Statistical calculations from data recorded by the authors were performed using the Chi-square, Mann-Whitney, and independent tests. Significance was set at P < 0.05.

RESULTS

The number of articles decreased annually. The highest number of publications was from Asia (64.3%), accounting for 71.4% of publications. The features of the septum were described for eight items, with one septum (70.14%) mentioned significantly more frequently, followed by on one side (65.89%) or the right side (62.22%). Location was mentioned significantly more frequently in the middle (55.22%) and for those aged 45 years and older (50.38%). No significant differences were observed in prevalence, age, height, or width between sexes; the patients' ages ranged from 18 to 90 years. Septa were significantly more prevalent in dentulous (45.38%) and partially edentulous (48.58%) patients, with significantly more patients exhibiting buccopalatal orientation (82.39%).

CONCLUSIONS

This study focused primarily on anatomical features using CBCT examination, and analyses of male-female differences and the origin of the sinus septum are necessary for the future.

Prevalence and Characteristics of the Maxillary Sinus Septa in a Saudi Arabian Sub-population: A Retrospective Cone Beam Computed Tomography (CBCT)-Based Study

OBJECTIVES

This study aims to investigate and determine the prevalence, location, and morphological differences of the maxillary sinus septa using cone beam computed tomography (CBCT) images in the Madina region and to discuss its clinical implications during sinus surgery.

METHODS

This study was a retrospective cross-sectional radiographic analysis of 808 CBCT scans from patients who attended Taibah University's College of Dentistry between December 2018 and June 2023. Age, gender, number of septa present per side, location (anterior, middle, posterior), morphology (complete or partial), and type (primary or secondary) were among the study variables. For data statistics, correlation analysis was utilized.  Results: Eight hundred eight CBCT scans were included with a mean age of 34.7±15.08. Septal bone was absent in 60.64% of the sinuses examined. Single septa were more common than multiple septa (p=0.009). Bilateral septal presence and the left septal bone were more common than the right, but none of these distributions were statistically significant. Males showed more sinus septa compared to females, but the difference was not statistically significant (p=0.420). Single septa were more prevalent in people under the age of 25.

CONCLUSION

More than 60% of the Madina population had patent sinus cavities with no septal processes, but males with single septal processes predominated.

Schneiderian Membrane Collateral Damage Caused by Collagenated and Non-Collagenated Xenografts: A Histological Study in Rabbits

BACKGROUND

The Schneiderian membrane (SM) that is in contact with biomaterial granules may become thinner and eventually perforate. It has been shown that these events are related to the biomaterial used. Hence, the main aim of the present study was to compare the damaging effects of two xenografts with different resorbability rates on SM. The secondary aim was to evaluate the possible protection from damage offered by a collagen membrane placed adjacent to the SM and by inward displacement of the bone window with the SM during elevation.

METHODS

Thirty-six albino New Zealand rabbits underwent bilateral sinus elevation. One group of 18 animals received deproteinized bovine bone mineral (DBBM group) and the other received swine-collagenated corticocancellous bone (collagenated group). Moreover, in the DBBM group, the bone window was displaced inward during elevation in one sinus together with the SM. In the collagenated group, a collagen membrane was placed adjacent to the SM in one sinus. Six animals were assessed per period after 2, 4, and 8 weeks.

RESULTS

The mean pristine mucosa width ranged between 67 µm and 113 µm, and none had a width of <40 µm. In the 2-week group, the elevated mucosa of the DBBM group presented 59 thinned sites and five perforations, while in the collagenated group, 14 thinned sites and one perforation were observed. Damage to SM decreased in number in the 4-week treatment group. In the 8-week group, the number of thinned sites in the DBBM group increased to 124, and the perforations to 8. In the collagenated group, 7 thinned sites and 1 small perforation were observed.

CONCLUSIONS

More damage to the Schneiderian membrane was observed in the DBBM group than in the collagenated group. The presence of the inward bone window offered protection from damage to the Schneiderian membrane.

Contribution to Bone Formation of the Schneiderian Membrane after Sinus Augmentation: A Histological Study in Rabbits

AIM

to evaluate bone formation in close contact with the sinus mucosa after different periods from sinus augmentation and the influence on healing of the presence of an inward dis-placed bone window.

MATERIAL AND METHODS

Eighteen rabbits were included in the experiment. A trap-door technique was applied at the test sites, and the bony window was elevated inward (inward window; IW) together with the sinus mucosa. At the control sites, the bony window was removed before the elevation of the sinus mucosa. The elevated space was filled with deproteinized bovine bone mineral (DBBM) and both access windows were covered with a collagen membrane. Histometric measurements were performed subjacent the sinus mucosa after 2, 4, and 8 weeks of healing.

RESULTS

Very few sinuses presented small percentages of new bone in close contact with the sinus mucosa in the various period examined. The presence of bone in the neighbor areas might have influenced bone formation close to the sinus mucosa. The inward displaced bone window supported bone formation close to the sinus mucosa only in the earliest period of healing, while the bone walls increased their influence over time. The lack of increased new bone percentage over time in the most central regions of the elevated sinus mucosa do not support the hypothesis that the sinus mucosa may express its potential in bone formation. It can be speculated that the new bone found in the intermediate and middle regions of the control sites in the earliest period of healing might be due to residual of bone from the osteotomy.

CONCLUSIONS

Very small amounts of new bone were found subjacent to the sinus mucosa, mostly formed from the bone walls, the inward displaced bone window or from possible bone residues from the osteotomy procedures. The lack of increased new bone percentage over time in the most central regions of the elevated sinus mucosa indicates that the contribution to bone formation provided by the sinus mucosa is limited.

Clinical and Histological Healing after Maxillary Sinus Floor Elevation

Sinus floor elevation is a surgical procedure that allows for the insertion of the implant in the posterior region of the maxilla in case of insufficient volume of native bone. Several studies have reported a high success rate, and this has helped to spread this surgical procedure around the world. The subject has been extensively studied and this could lead researchers to think that no new scientific evidence can be provided. However, new ideas and discoveries show that research never reaches a conclusion, and that new information can be added all the time. This collection aimed to provide new evidence that could be added to daily clinical work and to provide new ideas for future research.

A Reliable Surgical Procedure for Sinus Floor Augmentation with Antral Pseudocysts

An antral pseudocyst (AP) is a common well-defined ‘dome-shaped’ faintly radiopaque lesion of the maxillary sinus, and usually does not require treatment in asymptomatic patients. However, when sinus floor augmentation is required to increase bone volume for implant installation, the elevation of the sinus mucosa might drive the AP against the ostium. This might cause its obstruction and, as possible consequence, sinusitis. The purpose of this study was to investigate the clinical and tomographic conditions of APs to identify a predictable cyst removal that might allow a safety sinus floor augmentation. A total of 52 maxillary sinuses in 46 patients (mean age 55.1 years) presenting AP were examined by cone beam computed tomographies (CBCTs). A two-stage approach was applied. At the first surgery, the cystic lesions were further inspected by an endoscope through the antrostomy, and histopathological diagnosis of the removed tissues was carried out. After the confirmation of decrease of the swelling of sinus membrane by CBCT, the sinus floor augmentation was performed, at least four months after cyst removal. The color and transparency of the 86 cystic lesions were classified into 4 types. The whitish transparent cysts were 34 (39.5%), the yellowish transparent cysts were 18 (20.9%), the dark purple transparent cysts were 8 (9.3%) and the milky-white opaque cysts were 26 (30.2%). The contents of the 60 (69.8%) transparent cysts were serous fluid, but those of milky-white cysts were composed of viscous or elastic soft tissues, and the aspiration of the contents was unsuccessful. The analysis of the preoperative CBCT did not provide certainty on the contents of the cystic lesions. All cystic lesions were diagnosed as AP, and an infection was identified in one AP, presenting marked infiltration of the inflammatory cells. Considering the difficulties of performing a correct diagnosis of the AP content by a CBCT analysis, the risk of failure of the surgery that creates severe afflictions to the patients, and the necessity of a histological evaluation of the cyst, a two-stage surgery appeared to be the most reliable procedure.

Argon Bioactivation of Implants Installed Simultaneously to Maxillary Sinus Lifting without Graft. An Experimental Study in Rabbits

Background: The treatment of the surface of titanium implants with argon plasma improved its hydrophilicity and cell adhesion, resulting in higher bone apposition on implant and graft surfaces. The spontaneous perforation over time of the sinus mucosa after sinus augmentation has been documented in experimental studies at both implants and graft particles. The aim of the present study was to evaluate the influence of plasma argon treatment of the implant surface on bone apposition and on the rate of sinus mucosa perforations. Methods: A sinus lifting procedure was performed bilaterally in sixteen rabbits, and implants, either treated with argon plasma or left without treatment (control), were placed simultaneously without grafts. After 8 weeks, histological analyses were carried out. Results: A collapse of the sinus mucosa was observed at all implants. Twenty-four out of thirty-two implants presented sinus mucosa perforations at the apex. Several perforations were also found at the threads. Thinned mucosa sites (width < 40 µm) were found around almost all implants. About 2.6–2.9 mm of the apical regions of the implant did not present signs of osseointegration and about 1.3 mm were exposed to the sinus cavity. No statistically significant differences were found between plasma and control sites. Conclusions: In conclusion, the sinus mucosa was damaged and perforated by direct contact with treated and non-treated implant surfaces. The treatment of the implant surface with argon plasma did not affect the outcomes.