widen the occlusal table might be more detrimental in considering the occlusal factor when opposing a sometimes wider arch of teeth. As we reduce the alveolar crest which was flaring in a buccal or lateral direction we are also narrowing it thus creating an unnecessary cross-bite.

Sometimes, however, in order to be able to insert the blades the knife-edged ridge must be removed. In situations such as these, it sometimes becomes necessary to fabricate a removable prosthesis locked to a Dolder or Andrews bar which splints the blades and produces proper occlusion.

Labial undercuts in extreme knife-edge ridges should be re-moved to prevent possible perforations of the bur as it nears the labial concavities existing beneath the undercuts. Removing these overhanging situations gives the operator a clearer view of the existing ridge and enables him to have less complications when making the grooves. Lingually, in the maxilla, undercuts usually do not exist except in the tuberosities which should be ignored. In areas where implants are not to be inserted but only the pontics undercuts also should be ignored.

Lateral palatal exostoses are left since they do not interfere with the blades or the fixed prosthesis. However, in those situations where the palatal tissue may have been torn during the reflection it may be necessary to shave down some or even all of these exostoses so that healing of the palatal tissues will not be retarded.

Gingival sulci, deep supra-bony or infra-bony pockets may be treated during the insertion of the implants. However, in those cases where many periodontally involved teeth with soft tissue exist, the perio should be completed before inplantation.

Hypertrophied frena and high muscle attachments can be reduced surgically, but other conditions such as submucosal hyperplasia of the tuberosities, hyperplasia of the palate, etc. should be avoided and can disappear with the removal of the conventional denture and replacement of a fixed bridge supported by blades.

Remove or reduce by degloving submucosal tissues of hyper-mobile gingiva before or at the time the implants are inserted since they make "sloppy" resealing.

Sulcoplasty is done to gain stability for a conventional denture. This is not needed with implants. However, sometimes a form of sulcoplasty is done to lower muscle attachments.

All grooves for blades should be done on the lingual or palatal side of the jaw to allow a maximum amount of labial and buccal

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