Early loss of the primary cuspids -- along with the loss of primary molars -- can cause a decrease in arch length. Molars drift forward and anteriors move distally off the mid-line. Above, primary molars have been lost early, leading to a loss in arch length. The Horizontal Removable Appliance is ideal for regaining a small amount of arch length, while preventing the anteriors from shifting into the edentulous space. Horizontal lingual sheaths allow you to remove the arch wire in a mesial or distal direction -- without disturbing the molar bands. That allows you to remove the arch wire and make the necessary adjustments out of the patient’s mouth to increase arch length. Note: Make sure to protect the attachments from cement by placing wax in them prior to cementation.