From past to present, many arc formulas have been determined and presented for clinical use. Arc wires of standard sizes and special shapes are commonly used in flow. Clinical factors observing the growth and dimensions of the patient dental arch are the sum of the mesiodistal margins of the teeth, the arch width, and the arch depth. Studies show that properly aligned teeth are usually oval, square, and narrow.The possibility of variability of the arch size depending on the shape of the arch width, especially in the narrow and square arch forms of the inter-canine and inter-molar dimensions [16].
Differences in maxillary arch forms may be due to malocclusions. Many researchers have tried to identify arch forms in malocclusion types [12]. Sharma et al. [17], showed that the most common arch form seen in Angle class I malocclusion is oval, followed by tapered arch, while the most common arch form in Angle class II malocclusion is tapered. The results show that orthodontists should consider the oval arch form in the treatment of Angle class I malocclusion, and they should prefer wires with tapered arch form in Angle class II maloccclusion.The age range of the study is between 11–38 years.In this study, the difference between the sexes was not examined.
Murshid et al. [11], emphasized in their study that the ovoid arch was the most prevalent among class I and class II cases, with a prevalence of 94.4% and 69.4%, respectively. On the other hand, the square arch was the most prevalent among class III cases, with a prevalence of 90% for males and 77.8% for females. There was no significant difference between males and females in terms of the distribution of arch types. The age range of the study participants was between 14 and 18 years.
In the study of Olmez and Dogan [16] in the Turkish population, it was concluded that the most common dental arch shape in all malocclusions is the tapered form. This was followed by the oval arc form, then the square arc form. The study also shows that there is no significant difference between Angle Class I and Class II malocclusions.There is no significant difference between males and females in the distribution of arch types. The age range of the study is between 14–19 years.
Bratu D.C et al. [18], conducted a study to determine the maxillary and mandibular dental arch forms in Angle Class I, II and III malocclusions. In all malocclusions, the most common tapered arch form was found in the maxillary and mandibular arches, followed by oval and square arch forms. The age range of the study is between 14–19 years. In this study, the difference between the sexes was not examined.
Nojima et al. [6], used tapered, square and oval arch form templates to evaluate arch form in various malocclusions in Japanese and Caucasian populations. In the Caucasian population, 44% tapered, 38% oval and 18% square arch forms were found. In the Japanese population, 12% tapered, 42% oval and 46% square arch forms were observed. The average age of the participants in the study is between 14.5 and 16.8. In this study, the difference between the sexes was not examined.
Yun et al. [19], reported that the occurrance of the narrow arch form was noted in 8.8% of cases exhibiting normal occlusion. In contrast, within one malocclusion, the narrow arch form was observed at a slightly higher rate of 11,9%, as detailed by Nojima et al. [6].The study included individuals aged 17 to 30 years. Remarkably, there was no statistically significant difference in the distribution of arch types between males and females.
Raberin et al. [20], emphasized that in their study on individuals with normal occlusion, the white race made up 43% of the study group in which you carried narrow arc, and they saw less in Asian race than in white race with narrow arc, and higher rate in square arc in the study they carried out. The average age of the participants in the study is between 21.4 and 22.1.There is no significant difference between males and females in the distribution of arch types.
In our study, we conducted examinations on a total of 450 patients, consisting of 230 females and 220 males, all falling within the age range of 13 to 16 years. Among the male participants, the mean age was 13 years and 3 months, while the female participants had a mean age of 13 years and 2 months. Unlike the works of Sharma [17], Bratu [18], and Nojima [6], which did not explore gender disparities, our study specifically delved into the potential differences between genders. Similar to the results of Murshid [11], Olmez and Dogan [16], Yun [18], and Raberin [19], in our study also found no statistically significant gender distinction.
In the majority of traditional investigations, the configuration of arch forms has commonly been assessed with consideration given to the tips of tubercles and the edges of incisors. Frequently employed reference points in the evaluation of arch forms encompass the incisal edges of incisors or the crests of cusps. Notably, Herzog et al. [21], deviated from this norm and utilized the tops of buccal tubercles as their reference points in their study.
Another prevalent set of reference points used in research are clinical bracket points. Kook et al. [22], identified distinct ethnic dissimilarities between Korean and North Caucasian groups in their study. In light of this, they suggested the utilization of arch forms aligned with clinical brackets. Similarly, Dogan et al. [16], employed clinical bracket points as reference markers in their study.
In parallel with the approaches of Olmez and Dogan [16], as well as Kook et al.[22], our study also relied on bracket placement points to delineate and define arch forms.
In individuals with cleft lip and palate (CLP), a significant degree of variability exists in the extent and configuration of the cleft within the maxilla. This includes variations in tissue presence, interrelated structural relationships, and the potential for individual growth. Notably, the timing and nature of surgical interventions, as well as the proficiency of surgeons, play crucial roles in shaping the maxillary structure. These factors can both positively and negatively influence treatment outcomes for patients. While surgical procedures bring about beneficial effects, they also introduce morphological changes and new growth factors that often have adverse impacts on facial development [22–24].
Research in the realm of facial morphology among cleft lip and palate patients suggests that surgical interventions can result in hypoplastic arch dimensions. Some experts have noted that early primary surgical procedures for CLP individuals might unintentionally impede maxillary growth, leading to maxillary retrusion, anterior and lateral crossbites, and a collapse of the maxillary dental arch. These issues are frequently observed in individuals with unilateral cleft lip and palate (UCLP) and/or bilateral cleft lip and palate (BCLP). Moreover, dental arch dimensions in individuals with CLP tend to be smaller compared to those without clefts [22–25].
Athanasiou et al. [23], compared dental arch sizes in 72 children with UCLP in different age groups and children with normal growth and development. In measurements made on plaster models, the maxillary and mandibular arch widths and lengths of individuals in primary dentition (3–4 years), mixed dentition (8–9 years) and permanent dentition (12 years) were examined. The width measurements in the maxillary canine teeth region and primary 2nd molar or 2nd premolar teeth area were found to be smaller than normal individuals for all three age periods, and it was determined that they increased over time. The width between the maxillary permanent first molars was also measured lower in primary dentition and mixed dentition periods compared to normal individuals. At the age of 12, the difference between the maxillary intermolar distances of individuals with CLP and normal individuals was not statistically significant. Maxillary arch length measurements were similar for all age groups in individuals with CLP and were always recorded lower than in normal individuals.
DiBiase et al. [24], compared the maxillary arch dimensions of individuals with UCLP in the primary dentition and normal individuals without a cleft. Measurements of the maxillary arch dimensions of 44 children with UCLP and 44 healthy children showed that it was statistically significantly smaller in individuals with CLP, regardless of gender.
Suzuki et al. [25], evaluated the maxillary arch by measuring dental arch widths on plaster models they obtained at the age of 5 from 89 individuals with left unilateral CLP and 47 with right unilateral CLP. It has been shown that the maxillary arch widths of individuals with UCLP are less than the control group, and the mandibular arch dimensions are similar to the control group. In the group of individuals with UCLP, the segment on the side of the cleft was shown to collapse.The results of the study unveiled a noteworthy finding: regardless of gender, individuals with CLP exhibited statistically significant smaller maxillary arch dimensions when compared to the healthy group. This observation highlighted the distinctive structural variations present in the maxillary arch of children with UCLP during the primary dentition phase.
Kuijpers Jagtman [26], and Kozelj [27], evaluated models of 8-year-old patients with UCLP and found that maxillary posterior arch widths were statistically similar between children with UCLP and healthy children. However, it has been reported that the width of the maxillary anterior arch is narrower in children with CLP than in healthy children.The outcomes of the study revealed a significant insight: irrespective of gender, individuals with unilateral cleft lip and palate (CLP) demonstrated considerably smaller maxillary arch dimensions compared to the healthy control group. This observation accentuated the distinct structural variations within the maxillary arch of children with UCLP during the primary dentition phase.
In this study, among the individuals in the UCLP group, the tapered arch form constituted 37.3%, the ovoid form accounted for 32.7%, and the square form comprised 30% of the cases. Conversely, in the UCLP group, the square arch form was predominant at 46.4%, followed by the tapered form at 42.3%, and the ovoid form at 11.3%.No significant difference was observed in the relationship between gender and the UCLP, BCLP, or Control groups. Upon evaluating the connection between arch form and gender, it was found that there was no significant relationship between the two. However, when examining the relationship between arch form and the groups, a statistically significant difference emerged between the UCLP and BCLP groups compared to the Control group (p < 0.0000). Specifically, the BCLP group exhibited the highest proportion of square arch forms, while the UCLP group showed the narrowest arch forms. In contrast, the Control group primarily displayed the ovoid arch form, which was the most prevalent among them.