ĐÁNH GIÁ ĐỘ DÀY MÔ MỀM VÙNG ĐƯỜNG GIỮA KHẨU CÁI TRÊN PHIM CHỤP CẮT LỚP CHÙM TIA HÌNH NÓN (CBCT)

Abstract

Objective: The study aims to evaluate the soft tissue thickness in the mid-palatal region using CBCT imaging to provide guidelines for selecting safe and effective sites for orthodontic mini-screw placement in Vietnamese patients. Materials and Methods: The study was conducted on 70 CBCT images of patients aged 15–30 years. Soft tissue thickness was measured at specific points on a grid formed by horizontal lines perpendicular to the palatal suture at 4, 8, 12, 16, 20, and 24 mm posterior to the incisive foramen, and vertical lines parallel to the palatal suture at 2, 4, and 6 mm laterally. Results: The thickness of the palatal soft tissue varies by anatomical location, with a tendency to be thinnest at the midpalatal suture (1.1–1.51 mm) and progressively thicker toward the lateral aspects (1.47–3.2 mm). From anterior to posterior, the anterior palate tends to be thicker (1.44–3.2 mm), gradually thinner toward the posterior, with the thinnest area around the first maxillary molar (0.96–1.7 mm), and slightly increasing again in the posterior palate. The palatal soft tissue thickness in males tends to be greater than in females, with statistically significant differences at certain lateral positions (4 and 6 mm) at distances of 8, 12, and 20 mm from the incisive foramen (p<0.05), though the most favorable region is similar to that in females. The soft tissue thickness in the middle and posterior palate, at the midpalatal suture and 2-4 mm laterally, ranges from 1-2 mm. Conclusion: In Vietnamese people, the mid-palatal region from 8 mm to 24 mm posterior to the incisive foramen and within 2-4 mm laterally has a soft tissue thickness of 1–2 mm, which is the most favorable for stable, long-term mini-screw placement with minimal complications.