| Objective To study the changes of facial soft and hard tissue and the effect of vertical control in adolescent patients with high-angle skeletal class Ⅱmalocclusion treated withclear aligners. Methods A total of 32 adolescent patients with high-angle skeletal class Ⅱ malocclusion used invisible treatment in Hefei Stomatological Hospital from August 2021 to August 2023 were randomly selected as the study objects. All of them were treated with nonextractive orthodontics. The X-ray head shadow lateral film before and after treatment was used to measure 18 hard dental tissue and 6 facial soft tissue indexes. Results After treatment in 32 patients,the Angle between sella point,nasalroot point and upper alveolar seat point (SNA) increased .Sella point,nasal root point, and lower alveolar seat point (SNB) increased, while the upper alveolar seat point, nasal root point, lower alveolar seat point (ANB), angle between mandibular plane and orbital ear plane (MP-FH), the occlusal plane angle (OP-SN), and Y-axis angle decreased, with statistical significance (P<0.05).Theintersection angle from the long axis of the upper centeral incisor to anterior cranial base plane (U1-SN) and the long axis of the upper central incisor to the mandibular plane (L1-MP), and the angle between the upper central incisor and the lower central incisor had an increase (U1-L1), all the difference were statistically significant (P<0.05).Among the linear measurements, posterior height (S-Go) and mandibular body length (Go-Pog) increased, while posterior height to anterior height ratio (FHI) decreased, and the difference was statistically significant (P<0.05).Both the upper incisor teeth and the upper first molar teeth were depressed, and the difference was statistically significant (P<0.05). Among the soft tissue indexes, the distance from the upper lip to E line(UL-EP),the distance from lower lip to E line(LL-EP), soft tissue facial angle(Ns-Pog’-FH), facial convex angle(Ns-Snpog’), and Z angle decreased, and thenasolabial angle increased, with statistically significant differences(P<0.05). Conclusions Clear aligners provide good control of anterior torque and vertical height in class Ⅱ high-angle cases in adolescents, the occlusal plane is reduced, the mandible rotates counterclockwise, and the growth trend is good, which is beneficial to the improvement of the class Ⅱ relationship and the lateral appearance. |
