Missing Upper lateral incisors are very common. We see patients weekly that are missing # 7 or #10 or both. About 2% of the population is missing upper lateral incisors. The options are close space or open space and replace. I generally prefer to open the space and restore to normal. I feel this gives the best occlusion and esthetic result. If the patient does not require extraction and you can gain a Class I molar I absolutely do not want to close this space.
Ideally we want the cuspid to erupt forward into the lateral position to bring alveolar bone with it. It is then distalized into its proper position. If an implant is to be placed, a temporary can be placed during braces. A flipper can then be placed and designed to put pressure on the tissue and start shaping the tissue for the future implant. This can greatly improve the esthetics when the final restoration is placed.
If the patient is missing the lateral incisors it is often best to remove the deciduous laterals first. This is to try and get the cuspids to erupt forward.
The option of closing space is only used if the patient is older and has either a full Class II molar relationship and the space has closed forward, or it is a case that would require bicuspid extraction. It is hard to justify to the patient opening the space for an implant but extracting a bicuspid. I have seen a few auto transplant cases where the bicuspid is transplanted to the incisor site that have turned out beautiful- but that is a huge cost and most patients are not willing to go through all that’s needed to accomplish this. If done at a school for no cost as a teaching case many patients and parents will consent.