Adequate restorative space often requires the surgeon to perform an alveolectomy. In most situations, this is decided through clinical judgment. There are no specific objective guidelines to dictate the necessity of an alveolectomy, but information can be gained from a number of techniques.
CT Guided and Measured
In this technique, a CT scan is taken with the patient wearing a duplicate acrylic appliance with radiographic markers at the correct vertical dimension of occlusion. The patient is asked to smile so the lip position is visible in the CT image. Software is required to allow the soft tissue to be visible in the image. With software manipulation, the inter-arch distance can be accurately measured and the amount of reduction calculated, so as to hide the transition zone below the highest smile line.
Window Technique
A second technique is to create a window in a clear resin duplicate denture 5–6 mm from the position of the prosthetic-free gingival margin.10 The duplicate denture is placed intraorally and, following anesthesia, the surgeon scores the bone in the region of the window. On raising the flap, this marking serves as an indication of the amount of alveolectomy required.
Highest Smile Determination
A third technique is intra-operative deter- mination. In a patient with excessive display of the residual ridge crest, the surgeon may ask the patient to smile and then perform the alveolectomy 5 mm above the highest smile line.
Bone Reduction Guide
The above techniques work well in the edentulous patient. When a patient presents with a terminal dentition a bone reduction guide is required.
The bone reduction guide must satisfy the following requirements:
In a double-arch case, a minimum of 32 mm of inter-arch space is required. Impressions are made and duplicate diagnostic casts are cross-mounted. On one set of casts, the midline, vertical and horizontal overlap of the teeth and desired restorative space is marked. The gingival margins of the teeth are marked and the anterior teeth are removed from the cast. The model reduction is done and a diagnostic denture tooth set of the anterior teeth is completed. A duplicate of the diagnostic setup is made in clear acrylic resin. The flange portion of the guide is removed. The surgeon can use the gingival margin of the tooth as a reference from which to measure the bone reduction
At the time of surgery, the anterior teeth are removed and the guide is placed and indexed on the posterior teeth. With the use of a periodontal probe, the surgeon measures from the gingival margin of the guide to the existing bone. If inadequate space exists, bone reduction is completed to create restorative space prior to implant placement.
With precision in planning, adequate restorative space is created, which allows the restorative dentist to provide a restoration that satisfies the requirements of aesthetics, mechanics and hygiene.
Immediately following you LIVE patient experiences you will have the skills, confidence and support to offer this treatment option in your practice.