Gupta Seema, Bajjad Adeel A, Sharma Anil, Ummae Hani Sheikh, Kumar Anurag, Pandey Vatsal
Department of Orthodontics, Kothiwal Dental College & Research Centre, Moradabad, IND.
Cureus. 2024 Sep 7;16(9):e68857. doi: 10.7759/cureus.68857. eCollection 2024 Sep.
The upper nasolabial angle (UNLA) is an important determinant in clinical diagnosis and treatment planning. Therefore, the primary objective of this study was to assess the correlation between various skeletal parameters and nasal morphology in an Indian cohort, particularly UNLA. The secondary objectives were to evaluate sex differences in nasal morphology, optimal cut-off values of the UNLA for skeletal malocclusions, and differences in nasal morphology in different skeletal malocclusions.
This retrospective study used 162 pre-treatment lateral cephalometric records of patients with skeletal Class I, Class II, and Class III relationships. Group 1 consisted of 68 skeletal Class I patients (ANB angle of 2-4), Group 2 consisted of 68 skeletal Class II patients (ANB angle > 4), and Group 3 consisted of 26 skeletal Class III patients (ANB angle of less than 2). Each group was further subdivided according to the growth pattern into low (horizontal), average, and high (vertical) growers. The angle between the sella-nasion plane and mandibular plane (SN-GoGn angle) was used to further divide the groups according to their growth pattern into a horizontal growth pattern (SN-GoGn angle < 28), an average growth pattern (SN-GoGn angle of 28-36), and a vertical growth pattern (SN-GoGn angle > 36). The study sample was also divided into males and females to assess gender differences. Spearman's correlation coefficient, multinomial logistic regression analysis, Mann-Whitney U test, and Kruskal-Wallis tests were used. Receiver operating characteristic curves were used to obtain the optimal cut-off values for UNLA.
The UNLA showed a positive correlation with the sagittal position of the maxilla and a negative correlation with the sagittal position of the mandible and palatal plane (PP) inclination angle. Statistically significant sex differences were observed in nasal length, nasal depth, and lower anterior facial height. The optimal cut-off values for the UNLA angle in the class II skeletal pattern were ≥ 20, 16-20 for skeletal class I, and ≤ 16 for skeletal class III patients. None of the skeletal and nasal parameters were reliable predictors of the skeletal pattern type.
The present study showed that the UNLA increased in the skeletal class II pattern with the downward inclination of the PP. Patients with skeletal class III malocclusion had an upward-canted nasal tip.
鼻唇角（UNLA）是临床诊断和治疗计划中的一个重要决定因素。因此，本研究的主要目的是评估印度人群中各种骨骼参数与鼻形态之间的相关性，尤其是鼻唇角。次要目的是评估鼻形态的性别差异、骨骼错牙合畸形的鼻唇角最佳截断值，以及不同骨骼错牙合畸形中鼻形态的差异。
本回顾性研究使用了162例骨骼I类、II类和III类关系患者的治疗前头颅侧位片记录。第1组由68例骨骼I类患者（ANB角为2-4）组成，第2组由68例骨骼II类患者（ANB角>4）组成，第3组由26例骨骼III类患者（ANB角小于2）组成。每组再根据生长模式进一步细分为低（水平）、平均和高（垂直）生长者。蝶鞍-鼻根平面与下颌平面之间的角度（SN-GoGn角）用于根据生长模式将各组进一步分为水平生长模式（SN-GoGn角<28）、平均生长模式（SN-GoGn角为28-36）和垂直生长模式（SN-GoGn角>36）。研究样本也分为男性和女性以评估性别差异。使用了斯皮尔曼相关系数、多项逻辑回归分析、曼-惠特尼U检验和克鲁斯卡尔-沃利斯检验。使用受试者工作特征曲线来获得鼻唇角的最佳截断值。
鼻唇角与上颌骨的矢状位置呈正相关，与下颌骨的矢状位置和腭平面（PP）倾斜角呈负相关。在鼻长度度、鼻深度和下前面部高度方面观察到了具有统计学意义的性别差异。II类骨骼模式中鼻唇角的最佳截断值为≥20，I类骨骼为16-20，III类骨骼患者为≤16。没有一个骨骼和鼻参数是骨骼模式类型的可靠预测指标。
本研究表明，随着腭平面向下倾斜，II类骨骼模式中的鼻唇角增加。III类骨骼错牙合畸形患者的鼻尖向上倾斜。
