Orthopaedic correction of an anterior cross-bite

Abstract

Anterior cross-bites are common in growing patients due to different etiological factors such as: injury to the primary incisors with displacement of the permanent teeth; exfoliation of permanent incisors and palatal deviation because of a collapse in the premaxilla; supernumerary teeth and arch length deficiency. Objectives: To present a case of an anterior crossbite orthopaedic correction. Case report: An 11- year- old male patient was referred to the Orthodontics Clinic with an anterior crossbite and dental avulsion of a mesiodens due to trauma. The patient presented a dolichofacial pattern, a skeletal Class I relationship, horizontal mandibular growth, Class I molar relationship and retrusive maxillary and mandibular incisors. Treatment: First phase: Orthopaedics. Second phase: Orthodontics. An appliance similar to the Bite Block with a hyrax expansion screw placed parallel to the mid-palatal suture and a facial mask were constructed. Results: The patient´s anterior crossbite was corrected. Maxillary parameters were evaluated in relation to the Steiner, Jaraback and Ricketts analysis; SNA angle was increased by 4o , the convexity increased by 3 mm and the SNB angle, by 1o . Dental parameters showed that the interincisal angle decreased by 1o whereas SN/1 sup angle was increased by 8o . The patient´s soft tissues showed a positive change, which favoured the profile.Key words: Premaxilla, anterior cross-bite, facial mask.