Abstract: Nasolabial angle is commonly used to assess the soft tissue profile of the subnasal region. The aim of this retrospective study was to evaluate the relationship between the nasolabial angle, the inclination of the lower border of the nose and upper lip, upper incisor inclination and upper lip thickness. A sample of 142 female adolescents aged 13–18 years was chosen. A modified cephalometric analysis was performed with the nasolabial angle, and its components were traced according to Fitzgerald’s method. All analysed parameters showed a statistically significant correlation with the nasolabial angle (NLA). The highest correlation was found for the labial (L/FH) and nasal (N/FH) components of the nasolabial angle, respectively. Upper incisor inclinations (1+:SN, U1FA) and upper lip thickness (ULT) had a stronger correlation with L/FH than NLA, but no correlation was found between these parameters and N/FH. Upper lip thickness did not influence the relationship between incisor inclination and NLA or L/FH. The position of the upper incisors and upper lip thickness influence the nasolabial angle indirectly through its labial component (L/FH). Therefore, it seems purposeful to assess the nasolabial angle as a sum of two independent angles, of which only one (L/FH) can be influenced by orthodontic treatment.1. Introduction The desire to improve facial appearance and smile aesthetics is one of the main reasons that motivate patients to seek orthodontic treatment [1–4]. It is widely accepted that a disturbance of facial aesthetics caused by malocclusion can have a significant negative impact on a person’s self-esteem, as well as physical well-being. Improvement of one’s appearance as a result of orthodontic treatment may have a positive influence on their social and mental status. Modern orthodontic diagnostics should therefore consider not only the skeletal and dental relationships but also the patient’s soft tissue profile. When planning the treatment, orthodontists should pursue methods allowing correction of the malocclusion along with maintaining or, preferably, even improving facial harmony. One of the most valuable parameters used in soft tissue profile analysis is the nasolabial angle (NLA), formed by the intersection of the upper lip anterior and columella at the subnasale [5]. The mean value of NLA is 102◦ +/− 8 ◦ [5–7]. However, the measurement by itself does not provide adequate information about the component responsible for the variability [8,9]. A patient with retruded upper incisors, a receding upper lip and a drooping nose may have a nasolabial angle within the norm despite unsatisfactory subnasal aesthetics. Factors that may influence the nasolabial angle are upper incisor position [10–12], upper lip thickness [10], and the inclination of the lower border of the nose and upper lip [8]. In light of these reflections, it seems crucial to analyse each of the nasolabial components separately in order to avoid a diagnostic error that may negatively influence the treatment results.