ORTHOBITES Fig. 4 Fig. 7 Fig. 5 Fig. 6 Fig. 8 gingival buccal groove of the left lower first molar for a total length of 52.5mm. The upper first molars need 4mm more length than the lower molars or 56.5 mm. When the actual measurements were taken, they resulted in the following lengths. The lower C-C at disto-facial margin = 26mm; upper C-C at distofacial margin = 34mm; lower 3 – 3 from gingival buccal groove = 49mm; and the upper 3 – 3 from widest point on facial surface = 53mm. Note that the canines are primary teeth. There-fore, 4 additional mm must be added to the actual width of the upper/lower primary canines to simulate the actual width of the permanent canines. So lower C – C = 30mm and upper C – C = 39mm. To finish, one then simply takes the difference of the four actual measurements from the four projected measurements, and this provides the amount of transverse arch development required. Note: When the lower central incisors are small, I use the 30 mm as a projected width and when they are large, I use 35mm. For the full article, you may email me for a copy or refer to – JGO VOL. 3 December 1992. After determining my necessary lateral arch devel-opment, I then chose the two appliances I wished to achieve this with. www.orthodontics.com March/April 2013 11 Fig. 9
Journal of the American Orthodontic Society March-April 2013: Page 11
