like a conventional denture, sore spots on the mucosa over the mylohyoid ridge-crest or the anterior ridge, external oblique, genial tubercles or symphyseal area do not occur, nor is there any pressure on exposed neurovascular bundles.

After alveolar bone resorption takes place, there is a general loss of the attached gingiva. In cases of advanced alveolar atrophy, it sometimes becomes necessary to create free gingival grafts, etc. to form more attached gingivae prior to insertion of the blades.

The formation of papillomatous mucosal hypertrophies in the labial and buccal flanges from poorly fitting dentures usually never occurs with implants.

Muscle attachments that, because of excessive resorption of the underlying bone become extremely superficial, must be reduced otherwise they will pull away the attached gingiva from the posts of the implants or even from any natural teeth that might be in the area.

The initial incision for blades and subperiosteal implants is called a full thickness flap. Clean and atraumatic surgery pushing and not pulling away the periosteum, submucosa and mucosa from the bone must be the rule of thumb. As the incision is made, the implantologist must feel for the bone as he slowly cuts firmly through the entire thickness of the soft tissues and "scratches" the bone. He should make one continuous incision rather than join incisions from one side to the other. At all times the scalpel should be scratching the bone, otherwise the tissues can be torn when they are reflected. The anatomy of the area must be well understood.

Using blunted periosteal elevators around the nerves and carefully reflecting and separating the tissues avoids problems, especially when expecting an exposure of the neurovascular bundles in the mandibular canal or mental foramen. Sometimes when making an incision over extremely thickened tissue covering an extreme knife-edge ridge, it becomes almost impossible to touch the alveolar crest all around in an edentulous arch. Therefore, you must stop. Reflect the tissue as best as you can and then use the scalpel again as you approach closer to the bone. Do not tear or stretch the tissues. In areas where there is practically no bone above the mandibular canal, be very cautious with the scalpel and extremely careful as the tissue is reflected in order to prevent perforation through the egg shell wall covering the canal. The flap must:

1. be large enough to provide adequate access to the surgical field

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