Pre-Prosthetic Surgery (Preparing for Dentures)
The preparation of your mouth before the placement of a prosthesis (traditionally a denture) is referred to as pre-prosthetic surgery.
Some patients require minor oral surgical procedures before receiving a partial or complete denture, in order to ensure the maximum level of retention and comfort. A denture sits on the bone ridge, so it is very important that the bone is the proper shape. If a tooth needs to be extracted, the underlying bone might be left sharp and uneven. For the best fit of a denture, the bone might need to be smoothed out or reshaped. Occasionally, excess bone, called tori or exostoses, would need to be removed prior to denture insertion.
One or more of the following procedures might need to be performed in order to prepare your mouth for a denture:
- Ridge Augmentation – increasing bone in the alveolar ridge
- Vestibuloplasty – increasing the vestibular depth
- Alveoloplasty – bone smoothing and reshaping
- Torectomy (Tori removal) – removal of excess bone
- Excision – removal of pathologic gum tissue (ie, epulis fissuratium)
- Extraction of teeth – including impacted teeth
In general any bone removal is done in the most conservative manner. Gingiva (gum) is preserved as much as possible.
The alveolar ridge is the horseshoe shaped ridge of bone that all the teeth are rooted in. Alveolar bone loss occurs as the teeth are removed due to loss of stimulation of the bone. When replacing the teeth with an implant, a bridge or a denture it may be necessary to replace or augment the bone. This is done by bone grafting.
Loss of alveolar bone as mentioned above makes dentures not fit well. The denture needs a certain amount of ridge height to give it retention. Besides making the ridge bigger by adding bone one can also move the unattached (cheek tissues) gingiva away from the ridge. The vestibule is that part between the cheek and gums. Plasty of the vestibule can be done by various methods, the most reliable of which is grafting tissue obtained from another area. This could be obtained from the roof of mouth or the skin. The skin tissue can be obtained in a manner called split thickness or full thickness. When split thickness tissue is obtained it is usually taken from the thigh. A special cutting tool called a dermatome is used to take a very thin (0.015 inch) rectangle of skin. The skin grows back but will usually leave a slightly noticeable patch of different color and texture when healed. The full thickness graft must be obtained from non-hair bearing tissue. An excellent accompanying procedure is to perform blepharoplasty (eyelid surgery) and to transfer the excised tissue to the mouth. The patient can gain tissue where it’s needed and remove unwanted tissue all at once. The roof of the mouth (hard palate) is an excellent source of attached gingiva (gums). The tissue is the same type and thickness of the needed tissue and its source, the palate, is a renewable source. A graft taken from the palate leaves a patch which will completely grow back and can be used again in the future. The drawback to this procedure is that it is fairly painful. Of course, prescription for strong pain medicines is provided and a plastic shield is made to fit over the palate to protect it and decrease the pain.
Alveoloplasty is simply reshaping the alveolar bone. This is the horseshoe shaped bone teeth are rooted in. The alveolar bone sits on the basal bone of the maxilla (upper jaw) and mandible (lower jaw). Any time a tooth is removed alveoloplasty may be required to smooth rough or sharp edges or reduce protruding bone. When alveoloplasty is performed, it is done in the most conservative manner possible. Preservation of the bone is important because it naturally diminishes over time. When preparing the mouth for dentures the alveolar bone may need to be shaped so the dentures can fit over it. If overhanging bone creates an undercut the bone must be reshaped.
Bony protuberances on the tongue side of the mandible are called lingual tori. A similar protuberance on the roof of the mouth is a palatal torus. Tori can grow very large and even interfere with speech and eating. Removal of these is called torectomy. Torectomy may be done as part of preprosthetic surgery to prepare the mouth for dentures or it may be done to improve speech and eating. Tori grow throughout a person’s life. Around 35% of the population has tori.
To preview Pre-Operative Instructions, Consent and Post-Operative Instructions along with the scheduled visits, see Other Bone Grafting.