Related Experiment Video
Updated: Jul 2, 2026

Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Sinus membrane thickness of healthy endodontically treated maxillary molars
Deniz Yanık1, Ahmet Mert Nalbantoğlu2, Kürşat Er3
1Faculty of Dentistry, Department of Endodontics, Süleyman Demirel University, Isparta, Türkiye. deniz.yanik@yahoo.com.
Objective:
The study aimed to investigate the sinus membrane thickness (SMT) adjacent to healthy endodontically-treated maxillary molars with or without protruded apical foramen into the sinus cavity using cone-beam computed tomography (CBCT).
Materials And Methods:
Images of 207 non-smoker patients aged 18-40 were retrospectively analyzed, 140 were endodontically treated, and 136 were without endodontic treatment. Patients with any sinus pathology, teeth that have symptoms, or poor root filling were excluded. Study groups consisted of Group EM-I (endodontically treated and protruded apical foramen), Group EM-C (endodontically treated and contacted apical foramen), and similarly without endodontic treatment; Group M-I and Group M-C. SMT upon the mesial, distal, and palatal roots was measured. One-way ANOVA and Student's t-tests were performed.
Results:
Group EM-I had the thickest sinus membrane compared to other groups (p = 0.013). SMT values were 2.37-2.60 mm in Group EM-I, and 1.34-1.58 mm in other groups. Thickening (> 2 mm) percentages were 33.45% in Group EM-I and between 4.25 and 8.25% in other groups. No statistical difference was detected between first and second molars and genders (p > 0.05).
Conclusion:
When the apical foramen protruded into the sinus cavity, the conventional root canal treatment caused a minimal (between 2.37 mm and 2.60 mm) sinus membrane thickening with a rate of 33.45% based upon CBCT examinations.
Related Concept Videos
Nose and Nasal Cavity
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
Anatomy of Respiratory System I: Upper Respiratory Tract
Nose and nasal cavity
The nose and nasal cavity represent the main external openings of the respiratory tract.
Epistaxis
Etiology
Possible causes of this condition include high blood pressure, trauma, low humidity, upper respiratory tract infections, allergies, foreign bodies, nasal inhalation of corticosteroids or illicit drugs, excessive use of decongestant nasal sprays, facial or nasal surgery, anatomic malformation, tumors, or systemic...

