Fig. 8 Fig. 6 Fig. 9 Fig. 7 The last appliance component is two three-loop power chain segments that keep the lip bumper in place. The end power chain eyelet connects to the molar band hook (located under the lip bumper tube) and the front power chain eyelet connects to the lip bumper hook. Lip bumpers in different sizes may be ordered from orthodontic suppliers 5 or custom-made by an orthodontic laboratory. 4 dentition, the teeth will straighten but at the expense of the incisors flaring labially. This is the archwire effect (Fig. 6). 3 Furthermore, if this flaring occurs labial to the anterior bound-aries of the neutral zone when the case is finished, the incisors will be unstable with high risk of gingival recession and/or will relapse (Fig. 7). The Lip Bumper Effect Versus The Archwire Effect By eliminating the labial/buccal forces pushing inward on the mandibular teeth, the lip bumper corrects the sagittal (mild distaliza-tion) and transverse (mild buccal-ization) dimensions simultaneously. Crowded teeth unravel as arch length increase by dentoalveloar remodeling and apical base expan-sion. 3 This is the lip bumper effect (Fig. 5). The incisors maintain their axial inclination or if they are labi-ally inclined, even move to the lingual if that is the objective. If an archwire sequence is commenced on a lower crowded Lip Bumper Positioning in All Three Planes of Space Horizontally, the lip bumper needs to be 2 mm labial to the mandibular incisors. Using the GAC 036 plier (Fig. 8-A), slightly flatten (Fig. 8-B) the lateral U-shaped loops on the lip bumper. Doing so will tip the distal ends downward. Tip the distal ends back up to their original position. As the mandibular first molars slightly distalize and buccalize, the lip bumper will touch the labial of the mandibular incisors (Fig. 9). At the next visit (4-6 weeks), repeat the horizontal adjustment just described. Vertically, the lip bumper may be placed at three different levels (Fig. 10). 3 Using the GAC 036 plier, bend the ends of the lip bumper downwards if you want the anterior bow of the lip bumper to go lower in the vestibule. Fig. 10 www.orthodontics.com Summer 2022 9
Journal of the American Orthodontic Society Summer 2022: Page 9
