Chin cup effects using two different force magnitudes in the management of Class III malocclusions

Abstract

The use of a chin cup improved the maxillomandibular base relationship in growing patients with Class III malocclusion but with little skeletal effect. The utilization of either force had the same effects, except that the higher force had a more pronounced effect in reduction of ramus height.

Orthopedic Effect of Chin Cup during Mixed Dentition Stage

“…This observation is in agreement with the studies reported by Tuncer et al 11 and Altuğ et al 16 However, other studies failed to show any similar changes. 3,10,17 This study showed significant reduction of all mandibular skeletal variables (Ar-Go, Co-Go, Co-Gn, and SNB) except Go-Gn and this agrees with earlier studies. 3,10,11,17 This reduction could be explained as the result of the force of CC, which is applied directly to the mandible for trying to restrict its horizontal growth and convert it to some extent into vertical growth.…”

“…3,10,17 This study showed significant reduction of all mandibular skeletal variables (Ar-Go, Co-Go, Co-Gn, and SNB) except Go-Gn and this agrees with earlier studies. 3,10,11,17 This reduction could be explained as the result of the force of CC, which is applied directly to the mandible for trying to restrict its horizontal growth and convert it to some extent into vertical growth. 18 However, a study by Deguchi and McNamara 14 observed no significant changes by CC therapy in class III patients.…”

“…This study showed a significant increase in ANB and Wits appraisal, which is in agreement with other studies. 3,10,11,17 A significant increase in vertical angular variables (SN-Go Me, SN-Co GN) was also observed. This increase is due to the backward and downward rotation of the mandible.…”

“…Significant reduction of gonial angle was also observed in the study group, similar to the observations of the previous reports. 3,10,17 This effect may be due to the applied force passing through the occipital area and the glenoid fossa via the condyle. 14 Similar findings were reported in earlier studies.…”

“…Several cephalometric variables are found to be affected by the CC use, such as reduction of the SNB (sella, nasion, B point) and the gonial angle, increase in the anterior facial height, increase of the overjet (OJ), and slight reduction of the overbite (OB). 10,11 It is also used to open the bite along with an intraoral appliance or a bite-plate. 12,13 The reduction of SNB angle leads to restriction on the mandibular growth, significant rotation of the mandible, and significant increase of the OJ.…”