Mucoperiosteal tissues swell upon injury, and gradually re-turn to normal size, shape, and tone as they heal. Post-traumatic swelling must be taken into account in prosthodontic specifications. A soft tissue impression can be taken before surgery to compare with a bone impression to determine its thickness. Or, immediately after incising the tissues and prior to retracting them, their thickness must be measured. These dimensions are used to specify to the laboratory the height(s) of a subperiosteal implant's neck(s), or the height of the modified Dolder or Andrews bar extending from a pterygoid extension implant or toroplant.

In any implant case bladevent, subperiosteal, pterygoid, toroplant, or mixed implants — impressions for the final prosthesis are taken only after the mucoperiosteal tissues heal over the seated implants. A close fit of the restoration to the gum is desirable for esthetic and oral hygiene purposes.

In the maxilla hypermobile tissues are usually limited to the vestibular fornix (23) and the buccinator surface (24) — areas usually not directly involved with implant surgery or implant design.

Occasionally loosely-attached tissue is found in the maxillae when the ridge has resorbed so extensively that most of the bony base that anchored the thickened tissues is lost. The remaining soft tissue forms a mobile bulb (25) that overhangs the crest. The situation usually occurs posteriorly when the tuberosity (26) has severely resorbed or anteriorly when the ridge has become knife-edge with a large concavity on its labial surface (27).

It is more important to reduce overhanging, mobile tissue when planning a conventional denture than when using implants. The implants will be firmly anchored in or over bone, whereas the denture must sit on the soft tissues. Mobile tissue should be surgically attended in those sites where posts will protrude. Otherwise, unless it interferes with the restoration or esthetics, it may remain as is.

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