Early crossbite correction: a three-dimensional evaluation

Abstract

A crossbite (CB) occurs in approximately 4-23 per cent of young children and may lead to mandibular and facial asymmetry. Therefore, early intervention is often necessary to create conditions for normal occlusal and facial development. The aim of this study was to assess facial asymmetry and palatal volume (pre- and post-treatment) in two groups of children, one with a unilateral CB and the other with no crossbite (NCB). Thirty children with CB (13 males, 17 females, mean age 4.9 +/- 0.98 years) and 28 children with NCB (17 males, 11 females, mean age 5.3 +/- 0.36 years) were included in the study. Those with a CB were treated with an intra-oral expansion appliance. The faces and dental casts of the children were scanned using a three-dimensional (3D) laser scanning device at baseline (T0) and after six months (T1) of treatment. Student's t-tests were used to assess differences between the two groups in facial symmetry and palatal volume over the 6 month period. The CB children had statistically significantly greater asymmetry of the face (P = 0.042), especially the lower third (P = 0.039), and a significantly smaller palatal volume (P = 0.045) than the NCB subjects at baseline. There were no statistically significant differences between the two groups at T1. Treatment of a CB in the primary dentition corrected the facial asymmetry, particularly the lower part of the face. The palatal volume of the CB children increased as a result of orthodontic intervention to similar levels exhibited by the NCB children.

Three-dimensional evaluation of facial asymmetry in association with unilateral functional crossbite in the primary, early, and late mixed dentition phases

“…This is in accordance with previous studies that report a greater facial asymmetry in subjects with unilateral functional CB, particularly in the lower part of the face. 3 Previous studies have shown that sex and age do not affect facial asymmetry, 22,29 which is in accordance with the results of the present study. Furthermore, no significant differences were seen in the facial parameters within each group (CB and no CB) according to different dentition phases for the upper and lower facial parts.…”

“…3,[22][23][24][25] In the present study a landmark independent method, which has been previously reported to be a more accurate method for assessing asymmetry, 26 was used. It has been previously reported that subjects with unilateral functional CB already exhibit greater facial asymmetry in the primary dentition phase than do subjects without CB.…”

“…It has been previously reported that subjects with unilateral functional CB already exhibit greater facial asymmetry in the primary dentition phase than do subjects without CB. 2,3,6 Furthermore, it has been claimed that this facial asymmetry is the result of a functional mandibular shift that, if not treated, has a tendency to worsen during growth resulting in permanent skeletal asymmetry. 8,10 According to the present results, no face was perfectly symmetric, as minor, nonpathologic facial asymmetry or normal asymmetry is relatively common.…”

“…1,2 Unilateral functional CB commonly arises as a result of a narrow maxilla, which forces the mandible to displace laterally into an abnormal position because of the presence of tooth interferences. 2,3 Treatment of unilateral functional CB in the primary dentition period is still questionable in respect to costeffectiveness, 2,4,5 and it has been claimed that the main indication for correction in the primary dentition is the correction of functional asymmetry to prevent adverse skeletal mandibular growth. 2,6 The functional asymmetry observed in unilateral functional CB can contribute to mandibular skeletal asymmetry because during the growth period continuous condylar displacement in the glenoid fossa induces differential growth of the condyles.…”

Orthodontic approach to treatment of skeletal mandibular asymmetry: A case report

“…There have been reports of facial symmetry being reestablished after maxillary expansion [3][4][5]. However, after the growth is complete, TMJs suffer adaptive remodeling and a functional shift of the mandible can become a skeletal asymmetry.…”