Sinus Pneumatization Research Articles

Location of the Sphenoid Sinus Ostium in Relation to Adjacent Anatomical Landmarks.

The variability of sphenoid pneumatization and its relationship with the surrounding structures has been suggested. The aim of this study was to examine the effect of the surrounding bony structures on the position of the sphenoid ostium (SO). A prospective radiological review of computed tomography images of paranasal sinuses of 150 patients (300 sides) was conducted. Parameters investigated included the presence of Onodi cells, sphenoid rostrum pneumatization, and the type of sphenoid pneumatization on the coronal and sagittal planes. Their effect was studied on the vertical and horizontal plane using lines of measurement 1 through 5. The most common location of the SO on the horizontal plane was found to be in the middle third and was significantly affected by the rostrum pneumatization (P value <.001) and sphenoid pneumatization on the coronal plane (P value = .018). The location of the SO on the vertical plane was most commonly in the middle third. It was significantly affected by Onodi cell pneumatization (P value = .021) as well as the sphenoid height (P value <.001). Pneumatization of the sphenoid sinus and adjacent bony structures can affect the location of the SO. Presence of rostrum pneumatization and lateral sphenoid pneumatization shift the SO laterally. Presence of Onodi cell and low sphenoid roof shift the SO inferiorly. These variations need to be studied carefully before surgery in order to avoid operative complications.

Sinus floor augmentation using mixture of mineralized cortical bone and cancellous bone allografts: Radiographic and histomorphometric evaluation

Background/purposeDue to the pneumatization of the maxillary sinus, the sinus floor augmentation is often performed to implant placement in the maxillary posterior region. The aim was to perform radiographic and histomorphometric evaluation after placement of mixed allografts (cortical freeze-dried bone allograft [FDBA] 50%:cancellous FDBA 50%) during sinus floor augmentation. Materials and methodsIn 37 patients, anorganic bovine bone (ABB, sites = 16), mineralized cancellous bone allograft (MCBA, sites = 15), and mixed allografts (Mixed AG, sites = 20) were placed during sinus floor elevation via the lateral approach (LSFE), at total 51 sites with residual alveolar bone height (RBH) < 5 mm. Cone-beam computed tomography images were obtained before LSFE (T0), after surgery (T1), and 6 months after surgery (T2) for radiographic analysis. After a 6-month healing period, core biopsies were harvested and histomorphometric analysis was performed. ResultsThe mean augmented bone height (ABH) of ABB, MCBA, and mixed AG groups after surgery was similar (13.86 ± 4.19 mm, 13.99 ± 4.07 mm, and 14.20 ± 3.12 mm, respectively; P > 0.05). The mean ABH of ABB, MCBA, and mixed AG groups after 6 months was similar (13.72 ± 4.55 mm, 11.83 ± 3.31 mm, and 12.53 ± 2.97 mm, respectively; P > 0.05). In the ABB, MCBA, and mixed AG groups, the proportion of newly formed bone (NB) was similar (36.13 ± 10.01%, 39.26 ± 10.72%, and 31.27 ± 18.31%, respectively; P > 0.05). ConclusionThis result demonstrated that mixed AG led to sufficient bone augmentation and histologically comparable NB formation as compared to ABB and MCBA for sinus floor augmentation.

Combined Sinus Floor and Alveolar Ridge Augmentation Simultaneously Performed with Extraction of Ankylosed Maxillary Molar: A Case Report

This is a case report of combined sinus floor augmentation and alveolar ridge augmentation using a titanium mesh simultaneously performed with extraction of an ankylosed maxillary molar. An 18-year-old male presented with discomfort in the upper right molar. The maxillary right first molar was diagnosed with chronic apical periodontitis, ankylosis, and secondary dental caries. It was determined as hopeless prognosis due to the extensive secondary caries so we planned extraction of the tooth. Due to the pneumatization of the maxillary sinus and the vertical defects of the alveolar ridge, the bone dimension was insufficient for future implant placement. Sinus floor augmentation and alveolar ridge augmentation were performed simultaneously with extraction. Buccal flap was elevated for approach to the ankylosed root and the sinus. Piezosurgery was used for atraumatic removal of ankylosed tooth and the sinus window formation without the Schneiderian membrane perforation. Demineralized bone matrix and bovine bone mineral were grafted into the sinus and on the defected ridge. The sinus window was covered with a collagen membrane and a titanium mesh was installed at the ridge. Primary closure was achieved with buccal advanced flap and palatal rotational flap. Though there was titanium mesh exposure during the healing process, but sufficient bone formation was achieved. And the implant placement and the restoration procedures were successfully completed.

Objective and subjective assessment of astructured approach to computed tomography scans of the paranasal sinuses

HintergrundDie Voraussetzung zur Vermeidung potenziell schwerwiegender Komplikationen in der Nasennebenhöhlenchirurgie ist eine fundierte Kenntnis der individuellen Anatomie. Für die Nasennebenhöhlen stellt die Computertomographie (CT) die Bildgebung der Wahl dar, um die individuelle Anatomie und das Ausmaß der Erkrankung präoperativ darzustellen.Ziel der ArbeitDas Ziel der vorliegenden Arbeit ist die Bewertung des Nutzens einer CT-Checkliste zur Identifikation wichtiger anatomischer Normvarianten in der CT der Nasennebenhöhlen.Material und MethodenJung- und Altassistent*innen der HNO-Klinik wurden gebeten, CTs der Nasennebenhöhlen vor und nach der Einführung der CLOSE-Kriterien auf anatomische Normvarianten zu untersuchen. Der Prozentsatz der korrekt identifizierten Normvarianten wurde berechnet. Zusätzlich wurde der subjektive Nutzen anhand eines Fragebogens beurteilt.ErgebnisseSechs Jung- und 6 Altassistent*innen wurden in die Studie eingeschlossen. Die Rate der korrekt identifizierten Normvarianten verbesserte sich nach der Einführung der CLOSE-Kriterien signifikant von 23,1 auf 50,9 % bzw. von 24 auf 39,8 %. Die subjektive Beurteilung der CLOSE-Checkliste war sehr positiv.SchlussfolgerungEin strukturiertes Vorgehen zur Analyse von CTs der Nasennebenhöhlen kann die Identifikation kritischer anatomischer Strukturen verbessern und wird von Weiterbildungsassistenten als sehr hilfreich bewertet.

A Computed Tomography Study of the Prechiasmatic Sulcus Anatomy in Children

To investigate the characteristics of the prechiasmatic sulcus in children aged between 1-20 years. Patient files of 200 children admitted to the university hospital on 2019 were analyzed, retrospectively. The computed tomography images of patients were used to obtain anatomical knowledge containing prechiasmatic sulcus types and dimensions. The measurements related to the sulcal length (6.94 ± 1.25 mm) and sulcal angle (31.01 ± 18.13°) showed that the sulcal length did not alter in children between 1 and 20 years, whereas the sulcal angle did not vary from infancy to prepubescent period, but it was decreasing in postpubescent period. In 29 patients, the sulcal length was observed to divide into 2 parts with an evident angle. The interoptic distance and planum length were found as follows: 14.70 ± 2.85 mm and 14.84 ± 4.12 mm, respectively. The order of PS types was observed as type 4 (26.5%, 53 cases) > type 2 (26%, 52 cases) > type 1 (24%, 48 cases) > type 3 (23.5%, 47 cases). The sulcal length did not vary in children, whereas the sulcal angle decreased with an irregular pattern. The sulcal angle decreased after prepubescent period, possibly due to the sphenoid sinus pneumatization and spheno-occipital synchondrosis. The sulcal length angle mostly in infants and young children may cause surgical orientation difficult during the resection of tumors using transcranial approaches.

Perforation Risk Assessment in Maxillary Sinus Augmentation with Lateral Wall Technique.

Maxillary sinus augmentation is a procedure commonly performed in patients in need of maxillary posterior implants with loss of vertical ridge height and sinus pneumatization. Previous studies have identified some factors associated with sinus membrane perforation during lateral-wall sinus elevation procedures. Although membrane perforation does not directly link to future implant failure, it has been shown to have an association with postoperative complications. In order to promote more predictable results and reduce complications during the sinus elevation procedure, especially for the lateral window approach, articles published in peer-reviewed journals were reviewed to support the proposal of a new risk-evaluation system prior to the sinus surgery. This article reviews anatomical and patient-related factors that might affect the risk of perforation during the surgery and also aims to provide a risk assessment table to enable clinicians to analyze these factors prior to the lateral sinus augmentation surgery.

Maxillary Sinus Elevation Difficulty Score with Lateral Wall Technique

Maxillary sinus augmentation is a procedure commonly performed in patients in need of posterior maxillary implants with limited vertical ridge height and sinus pneumatization. However, minimal information has been presented to evaluate the complexity of the sinus elevation procedure via a lateral window approach based on patient examination, including extraoral findings, anatomical factors, and the possible influence from the surgeon's experience. Therefore, this article presents a new scheme of maxillary sinus floor elevation difficulty score based on comprehensive patient- and surgical-related factors. The proposed scoring tool aims to aid surgeons in performing a comprehensive presurgical evaluation prior to the lateral wall sinus augmentation surgery and also enhance communication between clinicians and patients regarding the complexity of the case.

Minimally Invasive Management of Implant-Supported Rehabilitation in the Posterior Maxilla, Part II. Surgical Techniques and Decision Tree.

Insufficient crestal bone is a common feature encountered in the edentulous posterior maxilla due to atrophy of the alveolar ridge and maxillary sinus pneumatization. Numerous surgical techniques, grafting materials, and timing protocols have been proposed for implant-supported rehabilitation of posterior maxillae with limited bone height. In the majority of potential implant sites, residual bone height is less than 8 mm and the clinician has to select either a lateral or transcrestal sinus-elevation technique or placing short implants as the correct surgical option. Nevertheless, guidelines for selecting the best option remains mostly based on the personal experience and skills of the surgeon. The role of sinus anatomy in healing and graft remodeling after sinus floor augmentation is crucial. In addition to the evaluation of residual bone height, the clinician should consider that histologic and clinical outcomes are also influenced by the buccal-palatal bone wall distance. Therefore, three main clinical scenarios may be identified and treated with either a lateral or transcrestal sinus-elevation technique or short implants. This article introduces a new decision tree for a minimally invasive approach based on current evidence to help the clinician safely and predictably manage implant-supported treatment of the atrophic posterior maxilla.

Minimally Invasive Management of Implant-Supported Rehabilitation in the Posterior Maxilla, Part I. Sinus Floor Elevation: Biologic Principles and Materials.

Alveolar bone resorption and maxillary sinus pneumatization occurring after dental extraction in the posterior region of the maxilla may be problematic when planning implant-supported rehabilitation. Various regenerative options are available, including guided bone regeneration, bone block grafts, and lateral sinus augmentation. These procedures are associated with significant complication rates, high morbidity, increased therapy duration, and high cost. Less invasive approaches, such as transcrestal sinus floor elevation, and using short implants have been proposed in an attempt to reduce these drawbacks. The aim of this study is to analyze available evidence to suggest predictable options and identify minimally invasive management of implant-supported rehabilitation in the posterior maxilla. This article concerns biologic mechanisms regulating new bone formation after maxillary sinus augmentation and examines characteristics of available implants and grafting materials to help the clinician select the most rational and convenient surgical approach according to specific situations.

CONSERVATIVE APPROACH FOR MANAGEMENT OF POSTERIOR ATROPHIC MAXILLA USING IMPLANT ASSISTED OVERDENTURE (CLINCAL TRIAL)

CONSERVATIVE APPROACH FOR MANAGEMENT OF POSTERIOR ATROPHIC MAXILLA USING IMPLANT ASSISTED OVERDENTURE (CLINCAL TRIAL) Nayrouz A. Metwally1* BDS,MSc, Ahmed M. Abdel-Hamid2 BDS,MSc,PhD, Ahmed M. Hommos3BDS,MSc,PhD, Nermeen A. Rady4 BDS,MSc,PhD ABSTRACT Introduction: Implant assisted prostheses provide a higher degree of patient satisfaction than traditional prostheses. However, severe atrophy of the edentulous maxilla and maxillary sinus pneumatization may reduce the available bone in the posterior region for a safe and reliable implant‑supported dental rehabilitation. Tilted implants in the anterior region of the maxilla were suggested to be useful in the treatment of posterior atrophic edentulous maxilla that allows the use of longer implants to gain more stability. This may preclude the use of conventional Implant overdenture abutments, requiring the use of divergence correcting attachments. Objectives: The aim of the present study was to clinically evaluate the effect of the use of Smart Box accompanied with OT Equator attachment in retaining the inclined implant assisted overdenture for atrophic maxilla. Materials and methods: Ten patients with posterior atrophic maxilla and partially dentate mandible with posterior occlusal stops were allocated for this study. For each patient, an implant assisted maxillary overdenture was fabricated using minimally invasive flapless surgical technique. Four implants were placed while the most anterior implants were axial and the most posterior implants divergent to 25 degrees using CAD/CAM surgical guide. The implants were loaded immediately by OT EQUATOR and smart box attachment retained maxillary overdenture. Each patient was evaluated clinically at the final prosthesis insertion (baseline), three, six and nine months post insertion. Modified gingival index (MGI), Clinical attachment Level (CAL) and Peri-implant probing depth (PIPD) are the clinical parameters that were evaluated. Results:MGI, CAL and PIPD revealed significant increase in both tilted and axial groups throughout the evaluation period intervals. Tilted implants group showed significantly greater increase in all parameters when compared with the axial group. Conclusions: Within the limitations of this study, it can be concluded that combination of axial and tilted implant assisted overdenture is a predictable treatment option in case of severely atrophic posterior maxillae.

Techniques and Graft Materials used in Maxillary Sinus Lift Procedure for Dental Implant Placement – A Review

Maxillary sinus is the first paranasal sinuses to develop, which is pyramidal in shape and it completes developing around 20 years of age with the eruption of the maxillary third molars. Pneumatization of the maxillary sinus occurs with time. Tooth loss may lead to loss of bone density, atrophy of bone and further pneumatization of the maxillary sinus leading to insufficient quality and quantity of bone for placing implants. Despite lots of literature and research being done, there is no clarity in obtaining consensus regarding the techniques and materials used in maxillary sinus lift procedures. This article reviews the various techniques and bone graft materials used in maxillary sinus lift procedures. The techniques include lateral window approach, hydraulic sinus lift technique, Piezoelectric Surgery technique, Transcrestal Approach, Osteotome Technique, and Balloon elevation technique. It can be concluded that the balloon antral elevation technique and Hydraulic Sinus Lift technique are more efficient techniques for maxillary sinus lift procedures. These techniques are known to result inless perforations, less chair-side time, comparatively easier, and the need for elaborate instrumentation is minimized. It can also markedly increase the success rates of implants in contrast to the conventional techniques which pose greater risks to the patient, more soft tissue trauma, more chair-side time and can expose patients to infections.

Is it enough to just increase the height of sub-antral bone during maxillary sinus augmentation or dose its depth matter?

Purpose: Many techniques for maxillary sinus floor elevation have been used prior to implant placement in case of sever sinus pneumatization. Two-stage lateral-window sinus lifting using titanium micromesh without bone grafting was carried out in the present study. The purpose of the study was a trail to solve a question, if it is enough to just increase the height of sub-antral bone or it is also important to elevate the Schneiderian membrane medio-laterally as much as possible to accommodate for dental implants later. Materials and Methods: Seven patients (11 sinuses) were included. A titanium micromesh was shaped in a tick shape and placed into the sinus through a lateral window to maintain the elevated membrane in place. Immediate, 6-months and 9-months postoperative cone beam computed tomography (CBCT) were performed to evaluate the relation between the medio-lateral extension of the mesh and the amount of the gained bone. Results: When the height of the formed bone was related to the depth of the titanium mesh, no significant difference could be observed at either 6 or 9 months. However, when the depth of newly formed bone was compared against the depth of the titanium mesh, a high significant difference was noted at both 6 and 9 months. Conclusion: At least two thirds of the sinus depth must be elevated to obtain adequate bone width for future implantation.

Objective computerised assessment of residual ridge resorption in the human maxilla and maxillary sinus pneumatisation.

Atrophic resorption of the maxillary alveolar ridge is a complication that makes implantological rehabilitation critical. Our aim was to develop a novel computer aided procedure for the accurate quantitative assessment of maxillary residual ridge resorption including pneumatisation of the maxillary sinus that goes beyond previously described approaches and to apply it to a large dataset. To develop and refine the method, we performed a retrospective analysis using computed tomography data from 405 patients to generate segmented, three-dimensional models of zygomaticomaxillary bones and maxillary sinuses. Using anatomical landmarks and orientation lines or planes, all models were aligned automatically to subsequently generate cross-sectional images (n = 2835), enabling the classification of atrophy as well as the quantification of volumes and caudal extensions of the maxillary sinuses. We developed and implemented an accurate and reproducible workflow for the semi-automated analysis of volumetric maxillary images. Comprehensive statistical analysis of the large quantitative dataset revealed various correlations of maxillary process heights and sinus volumes with atrophy class, age and region and identified conjectural trends over the patient group. The method was used successfully to process a large dataset to classify atrophy, to measure alveolar height parameters, and to quantify maxillary sinus volume, bottom volume and pneumatisation. Apart from the anthropometric value of the generated dataset, the method could be applied to provide additional and more accurate data to assess the necessity of bone augmentation in the context of three-dimensional planning before implantation.

Fetal Anatomy of the Optic Strut and Prechiasmatic Sulcus with a Clinical Perspective

The main objective of the study was to show the morphologic features of optic strut (OS) and prechiasmatic sulcus (PS) in the fetal skull base with a surgical anatomical perspective. Twenty-three fetal cadavers (9 female, 14 male) with an average age of 21.70 ± 3.12 (range: 16-28) weeks of gestation in the inventory of the Anatomy Department were included in the study. Measurements were made with a digital image analysis software and goniometer. The sulcal length, interoptic distance, planum length, and sulcal angle were detected as follows: 3.91 ± 0.74 mm, 6.88 ± 1.04 mm, 6.55 ± 1.51 mm, and 24.52 ± 9.51°, respectively. Considering the location of the posteromedial margin of OS according to PS, OS was identified as the sulcal in 56.5% (13 cases), postsulcal in 30.4% (7 cases), and asymmetric in 13% (3 cases). According to the sulcal length and angle, PS was identified as type 1 in 26.1% (6cases), type 2 in 21.7% (5 cases), type 3 in 30.4% (7cases), and type 4 in 21.7% (5 cases). Our findings suggest that the sulcal length and angle reach adult size in utero. Taking into account the fetal and the gathered adult measurements, the high percentage of steep angle compared to flat angle show that after birth, PS become more flat, probably depending on the variations of the sphenoid sinus pneumatization. Thus, more studies conducted on the alterations in PS and OS types relative to the pneumatization are needed in terms of patient positioning, selection of appropriate surgical approach, and intraoperative decision-making.

Assessment of sphenoid sinus types in patients with cleft lip and palate on cone-beam CT.

The aim of this study is to examine the sphenoid sinus morphology and variations in patients with cleft lip and palate (CLP) on cone-beam computed tomography (CBCT) images, and to compare them with healthy controls. CBCT images of 54 patients (28 males and 26 females,) with CLP and 54 age- and gender-matched healthy individuals (28 males and 26 females) were retrospectively evaluated. Sphenoid sinus main types (conchal, presellar, sellar, postsellar), sellar subtypes, clival and lateral extensions, and sinus septation were analyzed in CLP and control groups. The data were statistically analyzed using Chi-square test to compare the groups. A statistically significant difference was found between CLP and control groups for sphenoid sinus main types (p < 0.05). Presellar type was more commonly observed in CLP group (18.5%), while the postsellar (31.5%) and clival (17.7%) types were more frequent in control group. There was a significant difference between the groups among different sellar sinus subtypes (p < 0.05). A significant difference was detected between the groups for clival extensions of sphenoid sinus (p < 0.05), but no difference was found for the lateral extensions (p > 0.05). No significant difference was determined between groups for sphenoid sinus septation (p > 0.05). Significant differences were found between the CLP and control groups in terms of sphenoid sinus main types, sellar subtypes and the clival extensions. Knowledge of sphenoid sinus pneumatization in patients with CLP is important for preventing complications during transsphenoidal surgery.

Cone Beam Computed Tomography Analysis of Sphenoid Sinus Pneumatization and Relationship with Neurovascular Structures.

The sphenoid sinus is considered as the most variable pneumatized structure of the skull. The aim of the present study was to determine the prevalence of the Onodi cell as well as to evaluate the relationship between the sphenoid sinus type of pneumatization and the presence of surrounding neurovascular protrusion using cone beam computed tomography (CBCT). The CBCT images of 500 patients/996 sides [203 males (40.6%) and 297 females (59.4%)] were analyzed in this study. The type of sphenoid sinus pneumatization, prevalence of internal carotid artery (ICA) and optic nerve (ON) protrusion and dehiscence, and also the frequency of Onodi cell were assessed. The percentages of the conchal, presellar, sellar, postsellar (a), and postsellar (b) types of pneumatization were 1%, 11.5%, 35.5%, 38.9%, and 13.1%, respectively. The more the sphenoid sinuses pneumatized, the greater the frequency of ON and ICA protrusion and dehiscence of their wall to the sinus. The prevalence of Onodi cell was 38.8%. A significant correlation was found between ON dehiscence and the presence of Onodi cells. The present study demonstrated a significant relationship between the sinus type and frequency of neurovascular protrusions. Therefore, the sphenoid sinus extent of pneumatization might be useful in predicting the risk of iatrogenic damage to the surrounding structures.

Maxillary Sinus Pneumatization Following Extractions in Riyadh, Saudi Arabia: A Cross-sectional Study.

IntroductionIt is generally agreed that tooth extraction may lead to maxillary sinus pneumatization, resulting in a union between the sinus floor and the crest of the remaining bone in extreme cases. Studies that compared pre- and postextraction radiographs suggest that maxillary sinus pneumatization may occur after posterior tooth extractions. This study’s aim was to establish the prevalence of maxillary sinus pneumatization following extractions in Riyadh, Saudi Arabia.Material and methodologyIn this cross-sectional study, 282 panoramic images were randomly selected from the radiology department of the Dental University Hospital in Riyadh, Saudi Arabia, from the years 2015 to 2018. The radiographs included were of patients who had one of the following teeth extracted: the second premolar, the first molar, or the second molar. These radiographs were then evaluated for sinus pneumatization following extractions. The distance between the sinus floor and the inferior border of the alveolar ridge after the extraction was reviewed and assessed for all images.ResultThe six teeth that were assessed in this study were: 17, 16, 15, 25, 26, and 27. In relation to distribution (unilateral and bilateral), the results showed a statistically significant difference, especially for tooth numbers 16, 15, and 26. The mean values of change in sinus were significantly higher in the unilateral site than the bilateral site. However, the data did not provide any significant difference for the other three teeth (17, 25, and 27). The gender and molar side groups showed no statistical significance.ConclusionThe results of the study showed that maxillary sinus pneumatization may occur after posterior tooth extraction.

Relation between optic and carotid canals with sphenoid sinus in patients with communicant hydrocephalus: a computed tomography evaluation study.

There are neuro-ophthalmologic findings in patients with communicant hydrocephalus (CH). To investigate the relationships of the optic canal and carotid canal classifications at sphenoid sinus and anterior clinoid process (ACP) pneumatization in patients with CH. In this multicentric retrospective cross-sectional study, the cranial computed tomography (CT) images of 38 patients with CH (20 men, 18 women) and 40 controls (25 men, 15 women) were included. Optic and carotid canal classification at sphenoid sinus, ACP pneumatization, and sphenoid sinus septation were evaluated. In the CH group, type 3 optic canal was detected in 21.1% of the patients and type 4 optic canal was detected in 2.6% of the patients on the left side which was significantly different from the control group (P<0.05). In the CH group, type 3 carotid canal was detected in 21.1% of the patients (left) and 18.4% of the patients (right). ACP pneumatization was present in 13.2% of the patients in the CH group bilaterally. There were positive correlations between optic canal classifications and ACP pneumatization (P<0.05). There were also positive correlations between the right and left carotid canal classifications and ACP pneumatization (P<0.05). To avoid complications, CT should be evaluated carefully in patients with CH before surgical interventions in sphenoid sinuses and surgeons should work carefully in the sphenoid sinus or adjacent structures. The protrusion possibility of the optic canal or carotid canal to the sphenoid sinus may be higher in pneumatized ACP patients.

Sinus augmentation in atrophic maxilla: Lateral window approach

Rehabilitation of edentulous posterior maxillary regions by means of implant placement often poses challenging situations due to inadequate alveolar ridge height and poor bone quality. Since resorption of posterior residual ridge is caused by sinus pneumatization or traumatic extractions, maxillary sinus floor elevation (SFE) and bone augmentation with graft materials remains the method of choice. This scientific, evidence-based, preprosthetic procedure is a corrective technique available for almost two decades in such surgically compromised cases. In this article, we will discuss and review instrumentation by lateral window approach for SFE in conjunction with bone augmentation for delayed implant placement postgraft maturation in the healing period.

Variability of Paranasal Sinus Pneumatization in the Absence of Sinus Disease.

Background: Paranasal sinus pneumatization is a complex process, and numerous computed tomography (CT) studies document developmental variations in the setting of underlying sinus disease. The purpose of this study was to investigate variation in paranasal sinus pneumatization in a population of nondiseased subjects using a metric validated for tracking individual anatomic variants as well as total sinus volume.Methods: A total of 591 consecutive sinus and maxillofacial CT scans were considered for study inclusion. After patients with inflammatory sinus or respiratory disease were excluded, 323 CT scans were scored using the Assessment of Pneumatization of the Paranasal Sinuses (APPS) instrument, and relevant demographic data were recorded for each scan. APPS findings were compared according to demographic characteristics and laterality.Results: Laterality and sex were associated with differences in paranasal sinus pneumatization in a nondiseased population. Based on APPS score, the left side (4.95) was more pneumatized than the right (4.74, P=0.006), and males (10.16) were more extensively pneumatized than females (9.18, P=0.005). We found no correlation of age with sinus pneumatization (ρ=0.025). The probability of perceptible asymmetry in any given individual's paranasal sinus pneumatization was 69%, and the probability of left-sided dominance was 53%.Conclusion: Substantial anatomic variation exists in paranasal sinus anatomy, even among patients without sinus disease. Significant differences are found between males and females and between the left and right sides. Continued systematic research of paranasal sinus anatomy may facilitate a standard for CT sinus assessment that will aid clinician evaluation of anatomic variation and surgical decision making.