We believe that most experienced practitioners would select bilateral band and loop appliances in situations where both lower first primary molars have been lost and before the eruption of the mandibular permanent incisors has occurred. This approach will prevent later problems with permanent incisors erupting behind the lingual wire.

Nevertheless, the fixed bilateral lingual arch has the advantage of being a very stable appliance because of its two abutments. Many clinicians prefer it for that reason.

Both are very acceptable approaches, and the choice of a fixed lingual arch appliance or bilateral fixed band and loop appliances is left to the preference of the individual clinician.

Removable bilateral appliances are not the best therapeutic choice, especially for children in the primary dentition, although it is technically feasible to use them. The biggest problem is that children in the primary dentition age group are very unreliable when it comes to taking care of removable appliances, and the appliances are apt to become lost or damaged.

Of course, unlike the removable unilateral appliance, the removable bilateral appliance is too large to be a serious swallowing or choking danger.