Sinus Pneumatization Research Articles

The Use of CBCT in Evaluating the Health and Pathology of the Maxillary Sinus.

The use of cone-beam computed tomography (CBCT) has been increasing in dental practice. This narrative review summarized the relevance and utilizations of CBCT to visualize anatomical structures of the maxillary sinus and common pathologies found in the maxillary sinus. The detection/visualization rate, the location and the morphometric characteristics were described. For sinus anatomy, the reviewed features included the posterior superior alveolar artery, sinus pneumatization, sinus hypoplasia, sinus septa, and primary and accessory sinus ostia. For pathology, the following items were reviewed: membrane thickening associated with periapical lesions/periodontal lesions, mucous retention cyst, and antrolith. The visualization and assessment of the maxillary sinus is very important prior to procedures that take place in close proximity with the sinus floor, such as tooth extraction, implant insertion, and sinus floor elevation. Some sinus pathologies may be associated with odontogenic lesions, such as periapical diseases and periodontal bone loss.

Factors affecting the location of sphenoid sinus ostium: a binary logistic regression analysis.

Sphenoid sinus is a type of sinus surrounded by critical structures so that its injury potential to induce complications during surgery. The purpose of this study was to investigate the factors affecting the location of the sphenoid sinus natural ostium (SSO) to provide valuable data for endoscopic sinus surgery. Ostiomeatal unit (OMU) computerized tomography (CT) was performed on 198 subjects. Across the left and right sides, 396 evaluation results were obtained. The vertical distance to determine the location of the SSO was analyzed based on Lines 1, 2 and 3 on the sagittal image. The horizontal distance was analyzed based on Lines 4 and 5 on the axial image. The upper, lower, medial and non-medial borders were defined according to the location of the SSO. The presellar, sellar and postsellar types were categorized according to the level of sphenoid sinus pneumatization (SSP) on the sagittal image. The presence and absence of Onodi cells were defined on the coronal image. Binary logistic regression analysis was performed to investigate each factor. As the rostrum width of the SSO on the horizontal position increased, the position toward non-medial boarder increased by 4.902 times so that the natural ostium showed a trend of lateralization. For the postsellar type, compared to the presellar type, the position toward the non-medial boarder decreased by 0.223 times, indicating that the postsellar type had the natural ostium showing a trend of medialization. In the presence of Onodi cells, the position toward the lower boarder increased by 2.599 times with a significant association. The results in this study indicated that the presellar type of SSP had the natural ostium exhibiting lateralization with an increase in the rostrum width, whereas the postsellar type had the natural ostium exhibiting medialization with a decrease in the rostrum width. Based on these findings, the methods to widen the natural ostium may be diversified.

Cone beam computed tomography evaluation of sphenoid sinus in different sagittal skeletal pattern.

The purpose of this study is to explore sphenoid sinus variations in individuals with various sagittal skeletal anomalies using cone-beam computed tomography (CBCT). We retrospectively analyzed sphenoid sinus pneumatization on CBCT images of 126 patients aged 18-86 years. The anteroposterior skeletal relationships of the maxilla and mandible were classified as skeletal class I, II or III using the A point-nasion-B point (ANB) angle measured in the sagittal plane. The extensions of the sphenoid sinus were evaluated on three planes including axial, sagittal and coronal sections. The study population consisted of 84 females (66.7%) and 42 males (33.3%), including 52 (41.3%) class I, 38 (30.1%) class II, and 36 (28.6%) class III cases. The conchal type of sphenoid sinus was not encountered. Presellar sinuses were detected in only 3 (5.8%) class I cases. Incomplete sinuses were detected in 16 (30.8%) class I, 7 (18.4%) class II, and 15 (41.7%) class III cases. Complete sinuses were detected in 33 (63.4%) class I, 31 (81.6%) class II, and 21 (58.3%) class III cases. Lateral extensions were found in 103 (40.9%) of the 252 sinus walls: 33 (31.7%) in class I, 45 (59.2%) in class II, and 25 (34.7%) in class III sinuses. Regional sphenoid sinus anatomy can be carefully examined via CBCT. The sphenoid sinus pneumatization did not differ significantly in patients exhibiting different types of sagittal skeletal closure, with the exception of the lesser wing type.

Cone-beam computed tomography-based analysis of maxillary sinus pneumatization extended into the alveolar process in different age groups

ObjectiveThis study aimed to measure the amount of maxillary sinus pneumatization (MSP) extended into alveolar processes in different age groups via cone-beam computed tomography (CBCT) and its association with age.MethodsThe data of 293 adult patients (533 maxillary sinuses) who underwent CBCT at our hospital from January 2020 to October 2020 were analyzed and divided into the following age groups: group I (18–34 years old, youth group), group II (35–59 years old, middle-aged group) and group III (≥ 60 years old, elderly group). The distance between the lowest point of the maxillary sinus floor and nasal cavity floor in the central area of the maxillary posterior teeth was measured and recorded as the amount of MSP. Further, according to the positional relation between the maxillary posterior teeth and maxillary sinus floor, MSP was divided into type I (normal pneumatization) and type II (extensive pneumatization). The distribution of pneumatization types and degree and change of pneumatization for the different age groups were also analyzed. P < 0.05 was used as the threshold for statistical significance.ResultsThe amount of MSP of group I [(3.75 ± 3.77) mm] was significantly higher than that of group II [(2.30 ± 4.48) mm] and group III [(2.09 ± 4.70) mm], but there was no significant difference between group II and group III. We also found that the amount decreased gradually with increasing age (rs = − 0.2), with the youth group showing a higher prevalence of extensive pneumatization (youth vs. middle-age vs. elderly: 66.44% vs. 36.81% vs. 22.28%, respectively). There was no statistically significant difference in the amount of MSP between males and females and between left and right maxillary sinus in each group (P > 0.05).ConclusionThe amount of MSP was significantly higher in the 18–34 years old group compared to older age groups, showed a decreasing trend with age and was not associated with sex and maxillary sinus sides.

Risky anatomical variations of sphenoid sinus and surrounding structures in endoscopic sinus surgery

PurposeThis study aimed to examine the relationship between the sphenoid sinus (SS) and surrounding vital structures such as the internal carotid artery (ICA) and optic nerve canal (ONC) as well as the types of attachment of the sphenoidal septa onto these structures.MethodsIn total, 230 computed tomography (CT) scans were reviewed to study the type of sphenoid sinus pneumatization (SSP), the protrusion and dehiscence of the ICA and ONC, the relationship between the sphenoidal septa and surrounding vital structures as well as pterygoid recess pneumatization (PRP).ResultsThe most common SSP was sellar type (58.7%). The rates of protrusion and dehiscence of the ICA were 26.3 and 0.4%, and for the ONC, they were 13 and 1.5%, respectively. The ICA and ONC were most protruded and dehiscent in more extensive SSP. In 21.6% of patients, the intersphenoidal septa (IS) were attached to the wall of the ICA and in 8.6% they were attached to the wall of the ONC. The attachment of IS to the ICA correlated statistically significantly (p < 0.0001) with protrusion of the ICA. Accessory septa were detected in 30.4% of cases with various sites of attachment.ConclusionTo reduce the risk of injury and complications during endoscopic sinus surgery (ESS), surgeons should consider using CT to identify possible bulging and dehiscence of the ICA/ONC and their relationship to the extent of SSP and also to establish the presence of deviation of the sphenoid septum, and the presence of accessory septa.

The Relationship between Sphenoid Sinus, Carotid Canal, and Optical Canal in Paranasal Sinus Computed Tomography in Children.

Objectives The authors examined the structural differences in the paranasal sinus region at sphenoid sinus in the pediatric population. Methods Paranasal sinus computed tomography (PNSCT) images of 86 pediatric subjects (30 males, 56 females) were included. In 13 to 15 years of age group ( n =34) and ≥16 years of age group ( n =52), sphenoid sinus pneumatization (SSP), optic canal and carotid canal classifications and dehiscence evaluation were performed. Results In both sexes, type 1 and type 2 SS pneumatization were observed more frequently on both the right and left sides. On the right side, type 2> type 1; on the left side type 1> type 2 optic canals were detected in both gender. Type 3 optic canals were detected in 8.8 to 14.7% of the 13 to 15 years of age group; and 11.5 to 17.3% of ≥16 years of age group. Type 4 optic canals were detected in 2.9% of the 13 to 15 years of age group and 1.9% of the ≥16 years of age group bilaterally. Optic canal dehiscence was detected in 26.5% of the 13 to 15 years of age group and 17.3% of the ≥16 years of age group. Type 1 and type 2 carotid canals are most common in children, the percentages for type 3 carotid canals were 1.8 to 3.6% in children. Conclusion In pneumatized SS, optic canal classifications got increased values which showed protrusion into the sphenoid sinus wall. Therefore, in children, the surgeons must be very careful for optic canal being nearer to the sphenoid sinus walls.

Techniques and Graft Materials Used in Maxillary Sinus Lift Procedure for Dental Implant Placement

Posterior quadrant of the maxilla consider as special challenges for use of implant active prostheses to restore dental function. Placement of Implant in the posterior part of maxilla influence hesitation due to the lack of sufficient alveolar bone height. This occurs due to the proximity of alveolar crest to the maxillary sinus because of sinus pneumatization, along with resorption of bone of the alveolar ridge secondary to tooth extraction, pathological lesion or trauma. Sinus lifting to augment atrophic maxillary posterior area to create space for implantation has been progressively widespread in latest years. In literatures 2 approaches have been designated for sinus lifting: the direct approach called also lateral approach and the indirect approach called also crestal approach.

Investigation of the prevalence and main features of skull-base anomalies and characteristics of the sphenoid sinus using cone-beam computed tomography.

ObjectivesThis study aimed to define the prevalence and characteristics of skull base anomalies and the features of sphenoid sinus pneumatization (SSP).Materials and MethodsFive hundred cone-beam computed tomography scans were evaluated retrospectively for the presence of fossa navicularis magna (FNM), canalis basilaris medianus (CBM), sphenoid emissary foramen (SEF), and/or Onodi cells (OC). Patterns of the SSP and sphenoid sinus mucosa dimensions (SSMD) were also recorded.ResultsThe prevalence of FNM, CBM, SEF, and OC was 26.0%, 22.4%, 47.4%, and 18.4%, respectively. Two hundred sixty-two (52.4%) sellar-type SSP were defined, followed by post-sellar 191 (38.2%), pre-sellar 31 (6.2%), and conchal 16 (3.2%) types. The frequency of SSMD less than 1 mm, 1-3 mm, and greater than 3 mm was 40.6%, 38.4%, and 21.0%, respectively. An SEF was detected more frequently in females, while SSMD greater than 3 mm was more frequent in males. An FNM was more prevalent in the 18-29 and 30-39 age groups and SEF was significantly less frequent in patients over 60 years of age compared to other age groups. A sinus mucosa larger than 3 mm was more common in the younger than 18 year group. The frequency of post-sellar-type pneumatization was lower in patients younger than 18 years.ConclusionSkull-base anomalies are common and may be detected incidentally during imaging procedures. The sphenoid sinus, its variations, and pneumatization patterns should also be taken into consideration in imaging procedures performed for various purposes.

Relationships of sphenoid sinus pneumatization with internal carotid artery characteristics

ObjectiveWe explored the clinical significances of the relationships among sphenoid sinus aeration, intersphenoid sinus septum (ISS), and internal carotid artery (ICA).MethodsWe retrospectively reviewed the preoperative paranasal sinus computed tomography scans and the medical charts of 490 patients who were treated by the endoscopic endonasal transsphenoidal approach. We analyzed sphenoid sinus pneumatization, number of ISS, and positional relationships between the ICA and ISS (including ICA prominence and the thickness of surrounding bone).ResultsISS were often present in the ICAs of patients with presellar pneumatization (36.2%; p = 0.042). Sphenoid sinus pneumatization status significantly differed according to number of ISS (p < 0.001), ICA prominence (p < 0.001), ISS insertion into the ICA (p = 0.042), and distance from ISS to ICA (p = 0.004). When sphenoid sinus aeration was poor, the ICA was not prominent, and the ISS were attached to or lay close to the paraclival ICA.ConclusionsPatients with presellar pneumatization exhibited less prominent ICAs, and more ISS attached to or near the paraclival ICA, than did other patients. Therefore, particular caution is required when using the endoscopic endonasal transsphenoidal approach to treat patients with poor sphenoid sinus aeration.

Demonstration of the inferior intercavernous sinus is closely linked to the extent of pneumatization of the sphenoid sinus: useful information for the pituitary surgeon.

To study the utility of T2-weighted MRI sequences in the identification of the inferior intercavernous sinus (IICS), a potential source of bleeding during transsphenoidal surgery of pituitary adenomas. Pituitary sagittal T1W and coronal T2W MRI sequences were analyzed in 237 consecutive patients, after the exclusion of postoperative MRIs and those revealing an empty sella or a pituitary macroadenoma. Sphenoid sinus pneumatization was defined as incomplete (group 1) if it did not reach the nadir of the sella turcica, as complete (group 2) if it extended beyond the nadir of the sella or asymmetric (group 3), when only one side of the sinus was completely pneumatized. In Group 2 (70% of the patients), the IICS was rarely visualized on coronal T2W MRI (6/167 patients-3.6%), whereas in Group 1 it was identified in nearly all patients (55/57 patients - 96.5%, p < 0.001). In Group 3, the IICS was only visible above the non-pneumatized part of the sphenoid sinus. The IICS can be identified on coronal T2W images in patients with an incompletely pneumatized sphenoid sinus, but very rarely in patients with a totally pneumatized sinus. This information can help to increase awareness among pituitary surgeons of the need to potentially manage IICS bleeding during transsphenoidal surgery in patients with an incompletely pneumatized sphenoid sinus.

Location and patency of the ostium for sinus augmentation from an implant treatment planning perspective: A retrospective CBCT study

<h3>Background</h3> In the posterior maxilla, pneumatization of the maxillary sinus paralleled with resorption of the residual ridge markedly reduces bone volume. Sinus lift/sinus augmentation is usually performed to increase bone volume at these sites. The total height needed for augmentation depends on residual ridge height. The ostium, which is an anatomical conduit that opens into the middle meatus, must be patent; blockage due to inflammation or infection can lead to confinement of infection within the maxillary sinus. Clinicians should be cautious while planning sinus augmentation procedures in patients with radiographically evident sinus disease. <h3>Objective</h3> The objective of this study was to evaluate the location of the ostium with reference to the sinus floor and/or mucosal thickening when present. <h3>Study Design</h3> In total, 200 sino-nasal complexes comprising 100 dentate and 100 edentulous scans were retrospectively assessed using CBCT. The coronal section demonstrating the ostiomeatal complex was selected as a reference view to perform measurements of the sinus. The measurements were made by 2 evaluators. Comparative analyses of measurements were performed between dentate and edentulous patients. <h3>Results</h3> The safe height to which the sinus can be elevated without compromising the integrity of the ostiomeatal complex was calculated for each sinus. In the presence of significant mucosal thickening, the height available was calculated by subtracting the height of mucosal thickening from the sinus floor to the location of the ostium. The available height was approximately 27.05 mm for dentate and 23.40 mm for edentulous patients. The interoperator reliability was excellent for all parameters evaluated. <h3>Conclusion</h3> This retrospective study shows that CBCT is valuable in evaluating the location and patency of the ostium for planning sinus augmentation procedures for dental implant placement. <b>Statement of Ethical Review</b> Ethical Review or exemption was not warranted for this study

Characterizing the respiratory-induced mechanical stimulation at the maxillary sinus floor following sinus augmentation by computational fluid dynamics

Background: The relationship between maxillary sinus pneumatization and respiratory-induced fluid mechanics remains unclear. The purpose of this study was to simulate and measure the respiratory-induced mechanical stimulation at the sinus floor under different respiratory conditions and to investigate its potential effect on the elevated sinus following sinus-lifting procedures. Methods: The nasal airway together with the bilateral maxillary sinuses of the selected patient was segmented and digitally modeled from a computed tomographic image. The sinus floors of the models were elevated by simulated sinus augmentations using computer-aided design. The numerical simulations of sinus fluid motion under different respiratory conditions were performed using a computational fluid dynamics (CFD) algorithm. Sinus wall shear stress and static pressure on the pre-surgical and altered sinus floors were examined and quantitatively compared. Results: Streamlines with minimum airflow velocity were visualized in the sinus. The sinus floor pressure and the wall shear stress increased with the elevated inlet flow rate, but the magnitude of these mechanical stimulations remained at a negligible level. The surgical technique and elevated height had no significant influence on the wall pressure and the fluid mechanics. Conclusion: This study shows that respiratory-induced mechanical stimulation in the sinus floor is negligible before and after sinus augmentation.

Anatomical Parameters and Growth of the Pediatric Skull Base: Endonasal Access Implications.

Objectives Endoscopic endonasal anterior skull base surgery has expanding use in the pediatric population, but the anatomy of pediatric patients can lead to limitations. This study aims to characterize the important anatomical implications of the pediatric skull base using computed tomography (CT) scans. Design This study is designed as retrospective analysis. Setting The study setting comprises of tertiary academic medical center. Participants In total, 506 patients aged 0 to 18 who had undergone maxillofacial and or head CTs between 2009 to 2016 were involved. Methods Measurements included piriform aperture width, nare to sella distance (NSD), sphenoid pneumatization, olfactory fossa depth, lateral lamella cribriform plate angles, and intercarotid distances (ICD) at the superior clivus and cavernous sinus. These patients were then subdivided into three age groups adjusting for sex. Analysis of covariance (ANCOVA) models were fit comparing between all age groups and by sex. Results Piriform aperture width, NSD, sphenoid sinus pneumatization as measured using lateral aeration and anterior sellar wall thickness, olfactory fossa depth, and ICD at the cavernous sinus were significantly different among all age groups ( p <0.0001). Our results show that mean piriform aperture width increased with each age group. The mean olfactory fossa depth also had consistent age dependent growth. In addition, ICD at the cavernous sinus showed age dependent changes. When comparing by sexes, females consistently showed smaller measurements. Conclusion The process of skull base development is age and sex dependent. During preoperative evaluation of pediatric patients for skull base surgery piriform aperture width, sphenoid pneumatization in both the anterior posterior and lateral directions, and ICD at the cavernous sinus should be carefully reviewed.

Human Maxillary Sinus Development, Pneumatization, Anatomy, Blood Supply, Innervation and Functional Theories: An Update Review

The maxillary sinus is one of four pair’s air-filled spaces that surround the nasal cavity. The majority of previously published researches considering the maxillary sinus commonly concentrated on its pathological conditions and the recent surgical or medical management procedures. However, to understand the diseases of this sinus in a better manner, it is essential to have some basic medical details. Therefore, the present review is an attempt to focus light on this sinus by doing a cosmopolitan update on its development and anatomy, besides the functional theories by searching through many well-known scientific databases including Medline, Scopus, EMBASE, PubMed Central (PMC), PubMed, Cochrane Library, and Web of Science.&#x0D; In the current review, the author tried to approach, recognize and explain the fundamental data that may provide better ideas to imagine the pathological problems related to the maxillary sinus. In addition, the author did not conduct a new study on human nor animal subjects because the previously implemented articles were the chief and the only source for this review.&#x0D; In conclusion, the functions and physiology of the maxillary sinus are the subjects that reflect the anatomical complexity mentioned in the most recent articles may probably show that all its functions could be a part of a large and more complicated image than that apparent nowadays.

Pneumatization of the Sphenoidal Sinus May Affect Endonasal Cranial Base Reconstruction.

The aim of this study is to verify if the length of the nasoseptal flap is sufficient to cover the tuberculum sellae and planum sphenoidale of sphenoidal sinuses with varied degrees of pneumatization. Retrospective study of paranasal sinus computed tomography comparing the potential length of the nasoseptal flap and the length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches in conchal, presellar, sellar, incomplete postsellar, and complete postsellar sphenoidal sinuses. The length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches was directly related to the degree of pneumatization of the sphenoidal sinus. The nasoseptal flap length was adequate to cover the cranial base after transtuberculum approaches of all cases from the conchal, presellar, and sellar groups and the majority of cases from postsellar pneumatization. For transplanum approaches, the nasosseptal flap was sufficient to reconstruct defects in most cases from conchal, pre-sellar, and sellar type sinuses and in 54,9% and 19,2% in incomplete and complete postsellar, respectively. In well pneumatized sphenoidal sinus, the nasoseptal flap may not be sufficient to cover the cranial base after transtuberculum and transplanum approaches.

Treatment effects after maxillary total arch distalization using a modified C-palatal plate in patients with Class II malocclusion with sinus pneumatization

The purpose of this study was to evaluate the treatment effects after molar distalization using modified C-palatal plates in patients with Class II malocclusion with maxillary sinus pneumatization. This study consisted of 70 lateral cephalograms derived from cone-beam computerized tomography images of 35 patients with Class II malocclusion (mean age 22.3 ± 7.4 years) who had undergone bilateral total arch distalization of the maxillary dentition using modified C-palatal plates. The samples were divided into 2 groups according to sinus pneumatization; group 1 (n= 40), cephalograms with sinus pneumatization and group 2 (n= 30) cephalograms without sinus pneumatization. Paired t tests and independent-sample t tests were used to compare the changes in each group and between groups. The distal movement of the maxillary first molars was 4.3 mm for group 1 and 3.5 mm for group 2, with the intrusion of 1.4 mm and 2.5 mm, respectively. There was no statistically significant difference between the 2 groups. Group 1 showed 3.5° of distal tipping of the maxillary second molars, which was significantly greater than the 0.2° in group 2 (P<0.05). The total treatment period, including distalization, was 2.2 years for group 1 and 1.9 years for group 2, but the difference was not significant. There was no significant difference in the amount of distal movement and intrusion of the maxillary first molars between groups 1 and 2. Therefore, these results suggest that regardless of sinus pneumatization, molar distalization using temporary skeletal anchorage devices in Class II patients can be performed as a nonextraction treatment.

Major clinical findings of maxillary sinus surgery and the use of bio stimulators: a systematic review

Introduction: In the scenario of maxillary sinus surgery, when there is a loss of a dental element in the posterior region of the maxilla, there is natural resorption of the alveolar process and at the same time there will be pneumatization of the maxillary sinus. For this reason, the maxillary sinus floor elevation procedure should be performed. When grafting procedures are needed, our focus is often on the types of biomaterials and their bio stimulating properties, as well as on other types of bio stimulators to be used. Objective: It was to analyze the main clinical findings of maxillary sinus surgery and the use of bio stimulators through a systematic review. Methods: The present study followed a systematic review model, following the rules of systematic review – PRISMA. The search strategy was performed in the PubMed, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. The present study was carried out from January to March 2022. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: After analyzing the main clinical findings on maxillary sinus surgery and the use of bio stimulators, it was concluded that bone regeneration processes using biomaterials and the main molecular and cellular constituents such as mesenchymal stem cells, cytokines, platelet-rich plasma, fibrin-rich plasma, exosomes, microRNAs, TNF-α, IL-1, LIF and IL-6 and prostaglandin E2 (PGE2) are strategic for the solution to large bone defects, leading to tissue or bone regeneration. The main filler biomaterials can be fibrin-rich plasma (FRP), Bio-Oss®. However, it is necessary to understand the chemical, physical and biological processes of both the biological material and the biological niche of the host for successful neovascularization and bone filling.

Frontal sinus pneumatization: An isolated finding or a sign of concomitant anatomical variation?

To determine the association between frontal sinus pneumatisation and concomitant anatomical variations in paranasal sinuses as seen on computed tomography. A total of 403 patients who underwent paranasal sinus computed tomography were allocated to three groups according to the degree of frontal sinus pneumatisation (type 1 - hypoplasia; type 2 - medium size; and type 3 - hyperplasia). In this unique model, the prevalence of ipsilateral variations on paranasal sinuses on each side of the head were analysed separately within each pneumatisation group. The type 3 frontal sinus pneumatisation group showed a greater association with ipsilateral variations of the sphenoid bone. Variations included pneumatisation of the anterior clinoid process, lateral sphenoid recess, pterygoid process and greater wing, and exposure of Vidian canal. This group also showed significant associations with male gender, and the presence of frontal and Onodi cells. Interpretation of the paranasal sinus variations is imperative for pre-operative evaluation in functional endoscopic sinus surgery, particularly in patients with frontal sinus hyperplasia. Attention to variation on the ipsilateral side is informative.

Histomorphometric evaluation of different graft associations for maxillary sinus elevation in wide antral cavities: a randomized controlled clinical trial.

Pneumatization of the maxillary sinus can make it difficult, if not impossible, to install osseointegrated implants, and undertake their eventual functional rehabilitation, which may ultimately require regenerative techniques to achieve. This randomized controlled study proposed conducting a histological evaluation of the behavior of different graft materials in wide maxillary sinuses, at a height of 8 to 10 mm from the alveolar ridge, combined with bone remnants less than 3mm. Thirty-six patients underwent a sinus elevation procedure through the lateral window. The sinuses were randomly filled with the following materials (n=12/group): group 1, xenogenic bone + autogenous bone (ratio 70:30, respectively); group 2, xenogenic bone + L-PRF; and group 3, xenogenic bone. At 8 months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically in order to quantify newly formed bone tissue. The results showed a greater area of newly formed bone for G1, averaging 2678.37 (1116.40) μm2, compared with G2 at 984.87 (784.27) μm2, and G3 at 480.66 (384.76) μm2 (p < 0.05). Additionally, fewer xenogenic bone particles and a large amount of connective tissue were observed in G2. In maxillary sinuses with large antral cavities, autogenous bone combined with xenogenic bone seems to demonstrate better graft remodeling and improve bone formation, compared with the addition of L-PRF. L-PRF produces few advantages regarding new bone formation in the wide maxillary sinuses. Brazilian Clinical Trials Registry (REBEC) number RBR-2pbbrvg.

Is Resonance Frequency Analysis a Reliable Evaluation for Primary Stability of Implants Without Apical Contact?

The primary stability of dental implants is one of the most crucial factors for providing long-term success of osseointegration. Vertical deficiencies, such as those due to maxillary sinus pneumatization, may cause a severe vertical limitation to residual bone height. This study aimed to examine the primary stabilization of implants without apical contacts. Eighty bone-level implants (4.1-mm diameter/10-mm length) were placed into polyurethane test blocks without apical contacts. According to coronal bone-to-implant contact, groups were set as 4, 6, 8, and 10 mm, respectively. Resonance frequency analysis (RFA) using a SmartPeg was performed separately toward the transversal and horizontal axes by two independent researchers. Data were statistically compared for interobserver and among groups. Interobserver reliability varied from moderate to excellent (intraclass correlation coefficient [ICC]: 0.629 to 0.985). There were no significant differences among the 6 mm, 8 mm, and 10 mm groups, although the 4 mm group showed the significantly lowest stability (P < .001). Transversal and longitudinal measurements of the same groups did not show a parallel correlation statistically. RFA values may be affected by the finger torque in tightening of the SmartPeg among different researchers. Fully placed implants did not significantly show the highest stability among various apically contactless groups. Consequently, RFA should not be used alone to evaluate primary stability for implants without an apical contact.