## 1 Introduction  
Although the etiology of dental crowding is diverse [1; 2; 3], it has generally been thought that the presence of crowded teeth is attributed to maxillies that do not have enough space to accommodate teeth. The belief that crowding is associated with the size of the dental arch is intuitive and is supported by research showing greater crowding in people with smaller dental arches [4; 5]. In the pursuit of enhancing diagnostic precision and treatment planning in orthodontics, the accurate assessment of dental arch measurements stands as a critical element. Measurements such as dental arch perimetry, which is defined as the spatial capacity existing within the dental arch, designated for the alignment of teeth, have underscored the critical role that precise measurements on study casts play in the orthodontic diagnostic process [6]. Arch perimetry can be determined by a careful examination of the space available (arch perimeter) and the space required (tooth width) [7]. It is typically determined by measuring the distance from the mesial surface of the first permanent molar around the dental arch to the corresponding molar on the opposite side [8]. Considering that dental arch dimension is a factor that can contribute to dental malocclusion [9], determining the characteristics of dental arches is of paramount importance in orthodontic diagnosis and treatment planning, playing a key role in achieving optimal results. In addition to arch perimetry, among the crucial parameters, the assessment of the distance length between the second primary molars and the first permanent molars appears as a key factor, providing valuable information about the spatial relationships within the dental arch [10]. The accurate determination of these arch characteristics facilitates precise diagnosis and treatment planning, enabling orthodontic practitioners to tailor interventions that address individual patient needs effectively. In the management of dental crowding, it is essential to measure the amount of space in the dental arch to determine the appropriate orthodontic treatment approach. In cases where space deficiency is borderline, expansion may offer a viable solution, allowing for the treatment of malocclusion without the need for extractions, provided the patient's conditions allow this treatment alternative [11; 12; 13]. During mixed dentition, due to the eruption of the permanent incisors as well as the larger mesiodistal width of the temporary molars compared to that of the premolars, there is an increase in the perimeter of the upper arch [3]. Other authors have reported an increase in the perimeter of the dental arch by the end of permanent dentition, which is followed by a decrease in this size with age, especially in the mandibular arch [14; 15]. Several authors have extensively explored and elucidated diverse techniques for dental arch measurements in orthodontics. These techniques encompass a spectrum of quantitative analyses, including but not limited to arch perimetry, arch width and arch length as well as inter-arch relationships. Traditionally, these measurements have been conducted using the conventional method involving holding metal wires along the intended distances to be assessed and then measuring the length of the wire, a technique which, while widely practiced, may exhibit inherent limitations in terms of precision and efficiency [16]. Others have established it by applying a segmental arch technique based on a study cast with the help of digital calipers or by calculating the arch perimeter through mathematical means employing various equations and functions [17; 18]. Despite the pivotal role this metric plays, the methods employed to measure dental arch perimetry have, until now, faced inherent challenges in terms of precision and reliability. This research, therefore, sets out on a groundbreaking endeavor to address these challenges through the development, calibration, and verification of a novel tool expressly designed for determining dental arch perimetry.