To Evaluate the Relationship between Maxillary and Mandibular Base Lengths with Dental Crowding in Different Skeletal Malocclusions

Abstract

Introduction: Exploring the relationship between arch dimensions and crowding has long been a topic of interest. Many studies have found significant relationship between the two, while others have suggested that crowding is a multifactorial condition and is not dependent on arch dimensions only. Objective: To evaluate the relationship as well as sexual dimorphism between maxillary and mandibular skeletal base lengths with dental crowding in different skeletal malocclusions. Materials and Methods: The sample comprised 100 orthodontic patients (49 males, 51 females), which were divided into three groups based on the anteroposterior relationship of maxilla with the mandible. Each group was subdivided based on the severity of mandibular and maxillary arch crowding into two subgroups, and each subgroup was further divided into male and female subjects. Measurements of maxillary and mandibular base lengths (Co-A and Co-Gn) and tooth size arch length discrepancies were obtained through lateral cephalograms and dental casts, respectively, and measurements obtained were analyzed statistically. Results: Patients with class IB, IIB, and IIIB had significantly smaller maxillary and mandibular base lengths than subjects with class IA, IIA, and IIIA. A weak negative correlation was found between maxillary base length and maxillary crowding with r = –0.451 and p = .000, while a strong positive correlation was observed between maxillary and mandibular crowding with r = 0.742 and p = .000. Conclusion: An inverse correlation exists between dental crowding and the lengths of maxillary and mandibular bases, regardless of skeletal malocclusion.