---

Background and Objective: Maxillary sinus gradually extends laterally and inferiorly during pneumatization, and lamina dura of molar and premolar teeth can make a part of sinus floor. Knowledge about this anatomic relationship is essential to prevent complications paticularly iatrogenic perforation of sinus floor. Limitations of periapical and panoramic radiographs to visualization of this relationship led to the usage of cone-beam computed tomography (CBCT). This study was aimed to evaluate the vertical and horizontal relationship between roots of maxillary molars and sinus floor in CBCT images.
Methods: In this descriptive cross sectional study, ninety-five samples were selected of patients in Department of oral and maxillofacial radiology in Tabriz, Iran using simple randomization. Mean age of patients was 32.5 years old. Images were made by VGi cone beam Newtom and reconstructed by NNT viewer version 2.17. The vertical and horizontal relationship between roots of 139 maxillary first and 126 second molar teeth and floor of sinus evaluated.
Results: Type 2 was the most common relationship among the first and second molars, vertically (the inferior wall of the sinus located below the level connecting the buccal and palatal root apices,without an apical protrusion) and horizontally (the alveolar recess of the inferior wall of the sinus located between the buccal and palatal roots). There was a significant relationship between the type of tooth and sinus floor (P<0.05).
Conclusion: Most of the maxillary molar roots were in contact with sinus floor and sinus floor was extended mostly between buccal and palatal roots vertically and horizontally, respectively. Attention to sinus involvement possibility during interventions in maxillary molar region is important.

---

Understanding maxillary sinus hypoplasia (MSH) and associated sinonasal variants is crucial for the success of diagnostic and therapeutic procedures in maxillary sinus and maxillary dental implant surgery. The aim of this study was to investigate a rare case of unilateral maxillary sinus hypoplasia associated with lower orbital floor displacement, without involving the Uncinate process. A 31-year-old woman presented to the Department of Oral and Maxillofacial Surgery at Babol Dental School for rhinoplasty without any complaints of headache or nasal congestion. She had no history of trauma, congenital or bone diseases/abnormalities. Cone Beam Computed Tomography (CBCT) images revealed left maxillary sinus hypoplasia, lower orbital floor, and increased thickening of the sinus mucosa. The patient's photograph also showed lower displacement of the orbital floor. The diagnosis of unilateral maxillary sinus hypoplasia in this study was based on clinical manifestations and coronal views of CBCT and CT scans. Symptoms of hypoplastic sinus include chronic headache, facial pain, voice problems, or may sometimes be asymptomatic. If the surgeon is not aware of the hypoplasticity of the sinus, complications during surgery may increase, including post-surgery complications such as visibility of the low orbital floor and resulting patient confusion. This study highlights the importance of using CBCT as a valuable diagnostic tool to identify anatomical variations and details of the hypoplastic sinus. This approach helps the surgeon to inform the patient and provide an appropriate treatment plan, especially in cases involving dental implants or sinus surgery.
 

---

Background and Objective: Sinus extension is a physiological process that occurs in the growth cells of the paranasal sinuses and leads to increasing their volume over time, causing challenges in the dental implant process. This study was conducted to evaluate maxillary sinus morphometrics by cone-beam computed tomography (CBCT).
Methods: This descriptive-analytical study was conducted on the CBCT images of 100 people (52 male and 48 female) with a mean age of 45.32 ± 17.41 and the age range of 27 to 63 years referring to an oral and maxillofacial specialized radiology clinic in Babol, Iran during 2019. The amount of maxillary sinus extension in the panoramic-like view was recorded based on the amount of its extension in terms of the first anterior tooth and the last posterior tooth. In the new net technologies (NNT) software, in the section related to creating panoramic-like views, first, in the axial sections, the starting point of the maxillary sinus was specified from the occlusal side, and the mediolateral dimensions were measured at distances of 3 mm above and 3 mm below.
Results: The highest amount of maxillary sinus progress in the right anterior side was related to the mesial of tooth 5 (15%), and the highest amount of sinus progress in the left anterior side was related to the distal of tooth 3 (15%) and the mesial of tooth 4 (15%), which had no statistically significant differences. The most progress in the anterior area was related to the distal of the canine tooth and the mesial of the first premolar. The mean mediolateral sinus progress at 3 mm above the right nasal floor was higher in females than in males (P<0.05). Gender and age had no statistically significant relationship with maxillary sinus progress.
Conclusion: The maxillary sinus progress was almost equal in the left and right sides and also in males and females.

---

Background and Objective: The infraorbital canal (IOC) is located in the floor of the orbit and terminates at the infraorbital foramen below the orbital rim. The IOC is a crucial anatomical landmark for successful anesthesia in dentistry and oral and maxillofacial surgery. This study aimed to evaluate the position and dimensions of the IOC based on cone-beam computed tomography (CBCT).
Methods: This descriptive-analytical study was conducted on CBCT images of 250 individuals (105 males and 145 females) (mean age = 36.14±17.7 years) referring to a specialized oral and maxillofacial radiology clinic in Babol, Iran, during 2021-22. Three different types of IOC pathways from the sinus roof were measured: Completely located within the maxillary sinus roof (Type 1), located below the maxillary sinus roof (Type 2), and suspended from the maxillary sinus roof within the septum or lamella of the infraorbital ethmoid cell (Type 3). Additionally, the angles between the IOC and the infraorbital groove with the maxillary sinus roof, the angles between the IOC and the infraorbital groove, the lengths of the IOC and the infraorbital groove, and the distances of the IOC from various anatomical landmarks were measured. Distances of the IOC (mm) were evaluated from other anatomical landmarks according to gender and age groups.
Results: Overall, various pathways of the IOC from the sinus roof were 39.4% in Type 1, 53% in Type 2, and 7.6% in Type 3; the mean distance of the IOC to the infraorbital rim was 8.58±1.30 mm, and to the midpoint of the canine root was 10.16±0.81 mm. The mean length of the canal was 25.89±2.47 mm, and the infraorbital groove was 5.06±0.58 mm; and the mean angle between the IOC and the infraorbital groove was 153.20±3.28 degrees. In general, the distance of the IOC to the midpoint of the canine root on both the left and right sides was greater in males than in females, which was statistically significant on the left side (P<0.05). It was found that the length of the IOC and the angle between the IOC and the infraorbital groove on the left side had statistically significant correlations with age groups (P<0.05). The mean distance from the foramen to the infraorbital rim and the length of the IOC were proportional to the degree of nerve protrusion into the maxillary sinus; however, no significant correlation was found between the types of canals (degree of nerve protrusion) and gender.
Conclusion: Type 2 was the most common pathway of the IOC from the sinus roof. Although Type 3 was less common, due to the high risk associated with this type of canal, surgeons should be fully aware of the morphology and anatomical position of the IOC during sinus and orbital surgeries to reduce probable injuries.