## 4 Discussion  
The purpose of this study was to assess parameters such as width, anteroposterior length (AP), and inclination of the incisive canal depending on age, sex, and inclination of the upper incisors, and to identify a correlation between these parameters. This will allow the identification of groups of patients with an increased risk of complications in the form of resorption of incisor roots treated orthodontically. Knowing the risk of complications related to the anatomical structure of the incisive canal, it may turn out that an orthodontic compromise will be necessary in a certain population of patients to protect the roots and the periodontal apparatus rather than strive to achieve cephalometric standards. Previous studies have focused mainly on the analysis of the shape of the canal, its length from the nasal cavity to the oral cavity, the average diameter of the canal, as well as the relationship of these parameters with age, sex, type of malocclusion, or direction of facial growth [12; 13; 14; 15; 20; 23; 24]. Our research assessed the width of the canal in relation to age and sex. We described a relationship between the canal width and the angulation of the central incisors, as well as a correlation between the incisor inclination and the canal inclination. There was a clear relationship between the width of the canal and its AP length. In most age groups, the increased canal length was accompanied by an increased width at all levels (L1, L2, and L3). This means that people with a wide canal who require posterior root movement may be at an increased risk for two reasons. This is primarily due to the increased length of the AP canal. This may result in a smaller initial root-to-canal distance. Additionally, the width of the canal may exceed the inter-root distance between the central incisors. Only women over 30 years of age showed a negative correlation of these two parameters, i.e., they are characterised by a larger canal width than length. The inter-root distance in relation to the canal width may be of greater diagnostic importance in these patients than the AP root distance from the canal. Due to the significantly greater canal length at L1, men had a higher risk of cervical root-canal contact than women. In women, the length of the AP canal was definitely greater at L3 than in men. In the group of women, more attention should be paid when planning treatment involving axial retraction, torquing, or inclination of the incisor root due to the greater risk of apical contact. Studies in women have shown that the divergence of the incisor root increases with increasing canal width, which seems logical. For men aged 13 to 30 years, this correlation was negative, i.e., the wider the canal, the more parallel or convergent the roots. The analysis of the above data, especially at the L1 level, should lead to a more extensive diagnosis in men with parallel or convergent incisors on a panoramic radiograph. In this situation, there is a high likelihood that contact with the incisive canal will occur during incisor retraction or excessive torquing. This is due to the interapical distance being smaller than the width of the canal. It is this structure, not the cortical bone of the palate of the maxillary alveolar process, that may stand in the way and determine the degree of possible retraction. Women may be less at risk of resorption in this regard. This is all the more important as studies by [PERSON] et al. showed that in over 60% of patients, the width of the canal is greater than the interroot distance [14]. Analysis of the incisor inclination and the incisive canal inclination showed a very strong relationship, especially in the age group of 13 to 20 years. In women, the canal inclination increased with the increasing posterior movement of the incisors, while in men the opposite occurred. This parameter indicates a potential increased risk of resorption in this group of women in the case of excessive posterior movement of the incisors. The risk of pericervical contact is increased here.