Prevalence of maxillary sinus hypoplasia and association with variations in the sinonasal complex: a cone beam CT study

The Effect of the Maxillary Sinus Volume on the Morphology and Angulation of the Infraorbital Canal in Relation to Age and Gender

BACKGROUND

Although the infraorbital canal (IOC) and maxillary sinus (MS) have been well studied, understanding the effect of MS volume (MSV) on IOC morphology is critical in determining the safest surgical route for infraorbital depression and transmaxillary procedures.

OBJECTIVES

We aimed to describe the IOC types, measure the MSV and IOC angles (IOCA) in all three planes, and analyse the relationship between them using three-dimensional (3D) cone beam computed tomography (CBCT) images.

METHODS

CBCT images of 280 patients were analysed to identify the IOC types and accessory IOC (IOCa), and to measure morphometric parameters. The relationship between them was examined using statistical analysis in relation to age, gender, and laterality.

RESULTS

The most common IOC type was Type I (59.6%), followed by Type II (21.8%), Type III (13.6%), and Type IV (5%). According to MSV, three types of MS were described, with 38.2, 34.6, and 27.2% having normal, hypoplastic, and hyperplastic MS, respectively. Also, hyperplastic MS was associated with the highest likelihood of Type III IOC. Furthermore, logistic regression model revealed that the MSV and IOCA3 had a positive significant effect on the IOC protrusion, whereas being female, increasing age and IOCA1 had a negative significant effect on MS pneumatization. The probability of having hyperplastic MS, Types II and III IOC, IOCa also decreased with increasing age.

CONCLUSIONS

Using 3D technology, the results of this study provide a detailed classification of IOC and MS types, increasing the number of treatment options and reducing the risk of complications during surgery.

LEVEL OF EVIDENCE IV

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Maxillary sinus hypoplasia relevant to dental implant treatment: a narrative review

This comprehensive narrative review provides an overview of the current scientific evidence regarding maxillary sinus hypoplasia (MSH). This review highlights several variants of MSH that are relevant to implant planning and treatment in daily clinical practice. MSH is characterized by a reduction in sinus volume, which contrasts with maxillary sinus pneumatization, a condition that has received more clinical attention. Nevertheless, certain types of MSH can significantly impact implant surgery and the management of associated complications. The maxillary sinus volume can be affected by factors such as infection, trauma, genetic predispositions, and changes within the sinus or adjacent anatomical structures, including the nasal cavity and the ethmoid sinus. In cases of MSH, the maxillary sinus floor is positioned more cranially than the nasal floor, and the distance between the lamina papyracea of the eye and the middle meatus antrostomy point increases horizontally. Several variants of MSH potentially affect implant therapy. Chronic maxillary sinus atelectasis, which results from persistent ostium blockage, may have clinical implications, particularly when implant-related infections occur in the MS. Inferior meatus pneumatization involves a lateral expansion of the nasal cavity, requiring a nasal floor elevation procedure when placing implants in the posterior maxilla. Additionally, the formation of an ethmomaxillary sinus may create a septum-like structure in the distal area of the maxillary sinus, necessitating two separate bone access windows during the sinus floor elevation procedure. Given these considerations, it is crucial for clinicians to be aware of MSH. Accurate diagnosis of MSH requires the use of 3-dimensional radiography techniques, such as cone-beam computed tomography.

Comparison of the Paranasal Sinus Features of Paediatric Patients with and Without Cleft Palate: A CBCT Study

OBJECTIVES

This study is performed to compare the paranasal sinus volumes in paediatric unilateral cleft palate (UCP) and healthy patients.

METHODS

Cone-beam computed tomography (CBCT) images of 80 patients (40 boys, 40 girls) with UCP and 80 healthy individuals (40 boys, 40 girls) were evaluated. Paranasal sinus volumes were segmented and measured using ITK-SNAP software. Descriptive statistics, Kolmogorov-Smirnov, paired sample t-test and student t-test were performed for statistical analysis.

RESULTS

The volumes of ethmoid, frontal and sphenoid sinus on the cleft side were not significantly different than the non-cleft side (p>0.05) in UCP patients. Maxillary sinus volume of the cleft side in UCP patients was significantly lower than the non-cleft side (p<0.05). Mean maxillary sinus volume in UCP patients was 11825.23±509.95 mm3 at the cleft side and 13497.85±358.07 mm3 at the non-cleft side. While the mean volumes of ethmoid and sphenoid sinuses of patients with UCP were not significantly different from healthy individuals (p>0.05), the mean volumes of maxillary and frontal sinuses were significantly lower than healthy individuals (p<0.05). The mean maxillary sinus volume in UCP patients was 25323±597.8 mm3 and 26666±874.3 mm3 in the control group. The mean frontal sinus volume in UCP patients was 5633±323.1 mm3 and 5735±315.2 mm3 in the control group.

CONCLUSIONS

UCP caused a significant reduction in maxillary and frontal sinus volumes. The results of the current study show that paranasal sinus volumes in patients with UCP should be examined in more detail to make more risk-free and effective treatment plans.

Computed tomography assessment of maxillary sinus hypoplasia and associated anatomical variations: a systematic review and meta-analysis of global evidence

OBJECTIVE

To summarize the scientific evidence on the prevalence of maxillary sinus hypoplasia (MSH) and associated anatomical variations as assessed by computed tomography scans.

STUDY DESIGN

This PROSPERO-registered systematic review followed the recommendations of the PRISMA guidelines. Search algorithms were constructed for each of the six databases and gray literature. After screening the references (Rayyan®), the extracted data were meta-analyzed according to a random-effects model. The joanna briggs critical appraisal tool assessed the methodological quality of the included studies. The GRADE approach was used to estimate the certainty of the evidence.

RESULTS

From a total of 2781 studies screened, 22 were considered for four meta-analysis. The prevalence of MSH in 7358 patients was 5.65% (CI95% = 4.07-7.47%) with significant heterogeneity between studies (p < 0.001, I2 = 89.30%). MSH was identified in 295 patients, of whom 82.38% (CI95% = 75.82-88.09%) had unilateral hypoplasia and 17.62% (CI95% = 11.91-24.18%) bilateral hypoplasia with moderate heterogeneity between studies (p < 0.0503, I2 = 42.87%). The prevalence of MSH in 9998 maxillary sinuses was 3.77% (95% CI = 2.44-5.38%), with significant heterogeneity between studies (p < 0.001, I2 = 92.84%). Hypoplastic/aplastic uncinate process, concha bullosa and paradoxical concha were the most reported anatomical variations. The studies presented a low-moderate methodological quality. The certainty of the evidence was very low to moderate.

CONCLUSION

The prevalence of maxillary sinus hypoplasia observed was 5.65%, with most cases being unilateral.

Anatomical variations and abnormalities of the maxillary region and clinical implications: A systematic review and metaanalysis

OBJECTIVE

The objective of this review is to investigate and analyze the anatomical variations present in the maxillary sinus (MS), through the examination of the prevalence of these variations, as well as the corresponding prevalence of clinically significant pathologies and complications associated with them.

METHODS

The search process was carried out in the following databases; MEDLINE, SCIELO, WOS, CINHAL, SCOPUS, and GOOGLE SCHOLAR, using as search terms; "Maxillary bone," "Maxillary sinus," "Paranasal sinus," "Anatomical variations," "Sinusitis" and "Clinical anatomy."

RESULTS

A total of 26 articles and 12969 samples were included, from which 12,594 subjects had their sex recorded giving a total of 5802 males and 6792 females. The variants reported by the included were Haller cells, Concha Bullosa, Number of septa, Hypoplastic sinus, Agger Nasi, Thickening of the MS mucosa, Deviation of the nasal septum, Accessory ostium, and Onodi cells. Among the mentioned, the ones that presented the greatest number of studies (between 8 and 10 studies included) were: the Haller Cells, the Concha Bullosa, and the Number of septa, where prevalence was 0.30, 0.36, 0.39 respectively. These variations can lead to sinusitis, cause some types of tumors, or affect neighboring structures that could be compromised by this variation.

CONCLUSION

As a result, it is certainly complex to distinguish the presence of anatomical variations from pathological abnormalities. Therefore, knowledge of the different variations and their clinical relationships could be a useful asset for clinicians dedicated to this region.

A CBCT Study for Anatomic Variations of Osteomeatal complex in Patients With Cleft Lip and Palate

OBJECTIVE

To evaluate the anatomy and variations of osteomeatal complex (OMC) by comparing patients with nonsyndromic cleft lip and palate (CLP) and control group.

DESIGN

This case-control study was retrospectively analyzed using cone-beam computed tomography data.

SETTING

Istanbul University Faculty of Dentistry Department of Dentomaxillofacial Radiology.

PATIENTS

The study was conducted with 100 patients (44 females, 56 males) with CLP and 100 patients in the control group, which matched gender and age (with a maximum difference of 3 years).

VARIABLES

OMC variations are grouped as follows: ethmoidal, conchal, uncinate process, and septal variations. Then, we evaluated the presence of these OMC variations and compared them between the two groups.

STATISTICAL ANALYSIS

The McNemar's test was used to determine any significant differences between the groups for all indices at the 95% confidence level.

RESULTS

The most common anatomic variation in this study was Agger nasi cell (97%) and concha bullosa (97%) in the patients with CLP, while Agger nasi cell was the most common variation (99%) in the controls. Moreover, the atelectatic uncinate process was the least observed variation in both groups (1%). The incidences of paradoxical concha (58%;42%), bifid concha (29%;11%), deviated nasal septum (92%;80%) were significantly higher in the CLP group (p < 0.05).

CONCLUSIONS

The statistically significant results found when comparing OMC anatomy between the two groups reveal the importance of three-dimensional evaluation before functional endoscopic sinus surgery in patients with CLP.

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.

Relationship between Maxillary Sinus Hypoplasia and Maxillary Occlusal Cant: A Cone Beam CT Study

Introduction. Maxillary sinus hypoplasia (MSH) has been reported to cause a cant in the orbital plane. No similar reports exist about the possible impact on the maxilla. The aim of this study was to assess if MSH is associated with maxillary occlusal plane (MOP) cant and if dental or mandibular factors influenced the existence of the MOP cant. Methods. 80 cone beam CT images of subjects with MSH were analyzed for the type of MSH, degree of MOP cant, open or cross bite, mandibular asymmetry, and degenerative joint disease of the temporomandibular joints. The subjects were compared with a control group matched by age and gender. Results. The degree of MOP cant (range 0–5.1°) was not statistically significantly different in unilateral vs. bilateral MSH or between the different types of MSH. The frequency of open bite, crossbite, mandibular asymmetry, or degenerative joint disease in unilateral vs. bilateral MSH or between the different types of MSH was not statistically significantly different. Between the case and control, there was no statistically significant difference in the degree of MOP cant ( $1.3\pm {1.1}^{°}$ vs. $1.1\pm {0.9}^{°}$ , respectively) or frequency of dental and mandibular factors. There was low positive linear correlation between MOP cant and mandibular symmetry in MSH subjects (Spearman’s $\text{rho}=0.23$ ) and controls (Spearman’s $\text{rho}=0.18$ 7). Conclusions. The data suggests a view of the alveolar bone as the adaptable skeletal unit to ensure and bridge the functionality between the nasomaxillary complex and TMJ system–two systems with very different function, and therefore largely independent “matrix units.”

A Replicable and Reproducible Digital Method for Quantifying Maxillary Sinus Airway Changes after Sinus Lifts Using the Lateral Window Approach Technique-A Retrospective Study

In the present retrospective study, we aimed to assess the replicability and reproducibility of a novel digital measurement technique for analyzing the volumes of the left and right maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift procedure using the lateral window approach, to provide an accurate measurement technique for easily applying in clinical practice and to allow pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable. Material and Methods: Thirty patients with partially edentulous posterior maxilla were selected and submitted to bilateral sinus lift using the lateral window approach technique, with grafting materials selected and submitted to cone beam computed tomography (CBCT) scans, both pre- and postoperatively. Then, datasets were uploaded to therapeutic digital planning software to measure the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex. Gage R&R statistical analysis was performed to assess the replicability and reproducibility of the digital measurement technique. Results: The variability attributable to the novel digital measurement technique was 3.4% for replicability and 3.4% for reproducibility of the total variability of the samples. Conclusion: The novel digital method proposed is a replicable and reproducible technique for analyzing the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift using the lateral window approach technique, allowing an accurate pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable.

Association between Cone-Beam Computed Tomography and Histological and Immunohistochemical Features in Periapical Lesions Correlated with Thickened Maxillary Sinus Mucosa

Background and Objectives: Odontogenic sinusitis is a frequently underestimated pathology with fewer symptoms in patients with periapical lesions, periodontal disease, or iatrogenic foreign bodies in the maxillary sinus. The aim of our study was to determine the correlation between maxillary sinusitis and periapical lesions using cone-beam computed tomography (CBCT) imaging and histological and immunohistochemical investigations. Materials and Methods: A total of 1450 initial patients diagnosed with maxillary sinusitis in the Ear-Nose-Throat (ENT) Department, University of Medicine and Pharmacy “Grigore T. Popa” Iasi, Romania, were treated with anti-inflammatory drugs. Of these, 629 still had unresolved symptomatology and were later referred to the Dental Medicine departments for further investigations. Only 50 subjects with periapical lesions in the premolar/molar maxillary area were included in the present study. All the periapical lesions were observed on CBCT and classified using the Periapical Status Index (PSI) and the mean maxillary sinus mucosa thicknesses (MSMT). The enrolled patients underwent surgical procedures with the excision of periapical lesions. The excised samples were submitted to the histological and immunohistochemical investigations. Results: The 50 patients presented periapical lesions of their maxillary teeth in 328 dental units. There was a higher prevalence of periapical lesions in men than in women (chi-square test). We observed a significant difference between the mean MSMT of individuals with periapical lesions compared to those without (p < 0.01). Mean MSMT was 1.23 mm for teeth without periapical lesions and 3.95 mm for teeth with periapical lesions. The histopathological study identified 50% cases with periapical granulomas, 10% cases with periapical granulomas with cystic potential, and 40% cases as periapical cysts. Immunohistochemical stainings showed that CD4+ helper and CD8+ cytotoxic T lymphocytes, along with CD20+ B lymphocytes and CD68+ macrophages, were diffusely distributed in all periapical cysts and in some periapical granulomas, but CD79α+ plasma cells characterized especially periapical granulomas. Conclusions: The current study observed a significant correlation between CBCT maxillary mucosa thickness and type of periapical lesion. Chronic inflammatory lympho-histiocytic infiltrate predominates in periapical lesions, supporting the idea that lesion progression is determined by a humoral-type (CD20+ and CD79α+ B lymphocytes) but also by a cellular-type (CD4+ and CD8+ T lymphocyte population) immune mechanism.