# Nonsurgical Correction of Anterior Crossbite with Extra-Radicular Miniscrews--A Case Report
## 1 Introduction  
Class III malocclusion is characterized by a composite of dentoskeletal patterns that lead to the forward positioning of the mandibular teeth in relation to the maxillary teeth and a concave profile [1; 2; 3]. In terms of etiologies, genetic factors are considered more influential than environmental factors [3; 4]. The incidence of Class III malocclusions in the Asian population (14%) is much higher than that in Caucasians (1-5%) and the African American population (5-8%) [5; 6; 7]. The most common features of Class III malocclusion may include a retrogntain maxilla with proclined maxillary incisors and a prognathic mandible with retroclined mandibular incisors, although the components of Class III malocclusions may vary depending on the patient [1; 2].  
Therefore, treatment strategies for Class III malocclusion need to be adjusted depending on the age and severity of skeletal and dentoalveolar discrepancies. For adolescent Class III patients (CSI-3), a protraction facemask with or without RPE might be considered for orthopedic changes in the maxilla and zygoma [8; 9]. Recently, bone- anchored maxillary protraction with a facemask or Class III elastics was suggested to minimize dental side effects in conventional maxillary protection [10; 11; 12; 13; 14]. For adult Class III patients, if the discrepancy is mainly skeletal, orthopathic surgery might be the treatment of choice to improve facial profile with a stable occlusion [15; 16]. When patients decline the surgical approach, and the degree of skeletal discrepancies is still within the range of camouflage orthodontic treatment; the orthodontisti needs to determine whether the outcome will be protrusive after anterior crossbite correction [16]. If the answer is \"yes\", extraction would possibly be a better option for the treatment plan. With the help of TSADs, Class III malocclusion can be treated successfully using a nonextraction approach without the risk of subsequent period protrusion [17; 18; 19; 20; 21; 22].  
Temporary skeletal anchorage devices (TSADs) have been successfully applied in many clinical orthodontic cases, including maximal retraction in protrusion cases, ClassII correction, Class III correction, molar distalization in cases with crowding, molar intrusion in molar elongation cases, deep bite correction, open bite correction, midline correction, and the correction of canted occlusal planes and posterior crossbite [17; 19; 20; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38]. Transverse correction with miniscrew-assisted RPE (MARPE), bone-anchored maxillary protraction, and active vertical control with TSADs have also been considered in the past decade [38; 39; 40; 41]. BS miniscrews have been suggested to distalize mandibular dentition in Class III malocclusions [42; 43; 44]. This case report aims to demonstrate the need to use both IZC and BS miniscrews to reduce protrusion after anterior crossbite correction, which is a paradigm shift that greatly reduces the treatment duration and achieves a more pleasing facial profile after anterior crossbite correction [45; 46; 47].