Đặc điểm lâm sàng và X-quang bệnh nhân sai khớp cắn loại II xương có chỉ định nhổ răng hàm nhỏ tại Bệnh viện Răng Hàm Mặt Trung ương Hà Nội

To evaluate clinical characteristics and X-rays of class II malocclusions hyperdivergent patients at Ha Noi Central Odonto-Stomatology Hospital. Subject and method: Descriptive study by evaluate pre-treatment clinical characteristics and cephalometric radiography of 69 class II malocclusion skeletal with extraction premolars patients (hypodivergent group had 12 patients, hyperdivergent group had 27 patients, normodivergent group had 30 patients) at Department of Orthodontics of Ha Noi Central Odonto- Stomatology Hospital to September 2022 were recuited. Result: The average of age was 24.5 (range in 14 to 53). 100% protruding face type, lower face of hypodivergent group were short, lower face of hyperdivergent group were long, lower face of normodivergent group were normal. Hypodivergent group had SNA 87.83 ± 4.31°, SNB 81.96 ± 4.08°, ANB 5.79 ± 1.32°, GoGnSN 25.17 ± 2.65° decreased, NBaPtGn 89.8 ± 3.39° increased, ANS-Me 61.17 ± 7.75mm decreased. The inclination of upper incisor in relations with cranial base 109.35 ± 8.53° increased, base 118.17 ± 10.17° increased, angle between upper and lower incisors were sharp 112.3 ± 10.41°. Nasolabial angle was sharp 90.00 ± 11.35°, upper and lower lips were protrusive in relations with E-line (2.08 ± 1.82mm, 3.25 ± 3mm) increased. Hyperdivergent group had SNA 80.06 ± 14.59°, SNB 75.94 ± 2.82°,ANB 6.87 ± 1.92°, GoGnSN 40.22 ± 2.24° increased, NBaPtGn 81.4 ± 3.36° decreased, ANS-Me 65,33 ± 6,91mm increased. The inclination of upper incisor in relations with cranial base 118.17 ± 10.17° increased, angle between upper and lower incisors were sharp 111.71 ± 6.49°. Nasolabial angle was sharp 91.48 ± 12.57°, upper and lower lips were protrusive in relations with E-line (1.77±1.74 mm, 4.35 ± 2.11mm). normodivergent group had SNA 89.62 ± 15.31°, SNB 79.13 ± 2.2°, ANB 6.7 ± 1.61°, GoGnSN 33.92 ± 2.14°, NBaPtGn 84.15 ± 2.8°, ANS-Me 62.92 ± 5.93mm. The inclination of upper incisor in relations with cranial base 113.68 ± 7.53° increased, angle between upper and lower incisors were sharp 110.8 ± 9.11°. Nasolabial angle was sharp 89.62 ± 15.31°, upper and lower lips were protrusive in relations with E-line (2.43 ± 1.98mm, 4.4 ± 1.73mm) increased. Conclusion: Class II maloclusion skeletal patients with extraction premolars had protrusion, each group had different characteristics and X-rays: Hypodivergents had short lower face with low angle between mandibular related cranial base and facial angle increased, hyperdivergents had long lower face with high angle between mandibular related cranial base and facial angle decreased that means mandibular turn down and back so that influenced aesthetic face, normodivergents had specific class II skeletal maloclusion but normal vertical size of lower face.