This is the most difficult relationship in orthodontics. Special attention is needed to carefully place the lower second bicuspid bracket, because it is well back, and prone to contamination with saliva. The mesial of the lower first molar band should not be seated too low. This is a common error. Parallel seating of the band s occlusal surface.
Care is needed to avoid positioning the lower first molar band with the bracket too mesially.
The lower molar tube should straddle the buccal groove, mesio-distally. If there is a close bite on the lower first molars, the molar bracket should be at the correct height, as recommended in the bracket placement chart. It should not be positioned more gingivally. Also, temporary bonding material on the occlusal of the molars, or an acrylic bite plate can be used to avoid bracket interferences. A lower second molar band and tube can be used on the first molar if the bite is close.