Pre Prosthetic Surgery
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Transcript of Pre Prosthetic Surgery
IMPROVING THE PATIENTS DENTURE BEARING AREAS AND RIDGE RELATIONSDr. Rajat Dang
INTRODUCTION A thorough examination of the mouth prior to the construction of complete dentures is necessary to identify potential problem areas. A determination of whether surgery is necessary is an essential part of that examination and plays an important role in successful patient management. The vast majority of patients for whom complete denture therapy is prescribed have already been wearing dentures. There is a risk in wearing dentures for prolonged periods. This risk, or biologic price, manifests itself in a number of adverse changes in the denture foundations. Consequently, several conditions in the edentulous mouth should be corrected or treated before the construction of complete dentures. Often patients are not aware that tissues in the mouth have been damaged or deformed by the presence of old prosthesis.
Other oral conditions may have developed that must be altered to increase the chances for the success of the new dentures. The patient must be cognizant of these problems, and a logical explanation by the dentist, supplemented by radiographs and where required, diagnostic casts, usually will convince the patient of the necessity for the suggested treatment.
The methods of treatment to improve the patients denture foundation and ridge relations are usually either non-surgical or surgical in nature, or a combination of both methods. A treatment plan calling for surgical correction should be made only after alternate non-surgical approaches have been considered and evaluated. A patient who presents with deformed, abused pathologic tissues from an existing denture should first undergo non-surgical approach.
It is always hoped that the results of the preprosthetic surgery are acceptable both surgically and prosthodontically. In this vein, the services of an oral and maxillofacial surgeon may be required, especially as the surgical preparation becomes more complicated. In these instances, a team approach is needed with the surgeon and the prosthodontist serving as equal members of the team.
Since the support, retention, and stability of a denture base depend on the quantity and quality of the denture bearing area and border seal, every effort is to be made to preserve the alveolar bone. The goal of pre-prosthetic surgery is to modify the denture bearing areas to render it free of disease and to make its form (and possibly its function) more compatible with the requirements of complete denture wearing.
Some of the characteristics of this ideal form which provide for maximum support and stability and minimum interference with function are: Adequate bone support for dentures. Bone covered by adequate soft tissue. No undercuts or overhanging protuberances. No sharp ridges. Adequate buccal and lingual sulcus. No scar bands to prevent normal seating of denture. No muscle fibers or frenula to interfere with the periphery of the prostheses. Satisfactory ridge relationship between the maxilla and the mandible. No soft tissue folds or hypertrophies on the ridge or sulci. A ridge free of neoplastic disease.
NON-SURGICAL METHODS Non-surgical methods of edentulous mouth preparation include: Rest for denture supported tissues. Occlusal and vertical dimension correction of old prostheses. Good nutrition Conditioning of the patients musculature
Rest for denture supporting tissues: Rest for the denture supporting tissues can be achieved by the removal of the dentures from the mouth for an extended period or the use of temporary soft liners inside the old dentures. Regular finger or toothbrush massage of denture bearing mucosa, especially of those areas that appear edematous and enlarged is also beneficial.
Tissue abuse caused by improper occlusion can be made to disappear by, Withholding the faulty denture from the patient. Adjusting/correcting the occlusion and/or refitting the denture by means of a tissue conditioner. Substituting properly made dentures.
In these cases, it is necessary to allow the soft tissues to recover by removing the dentures for 24-48 hours before the impressions are made for the construction of new dentures. However, it generally is not feasible to withhold the patient's denture for an extended period while the tissues are recovering. Therefore, temporary soft liners have been developed as tissue treatment or conditioning materials. These soft liners maintain their softness for several days while the tissues recover.
Occlusal correction of old prostheses: An attempt should first be made to restore an optimum vertical dimension of occlusion to the dentures presently worn by the patient by using an interim resilient lining material. This step enables the dentist to prognosticate the amount of vertical facial support that the patient can tolerate, and it allows the presumably deformed tissues to recover. The decision to create room inside the denture depends on its fit and the condition of the tissues. The tissue treatment material also permits some movement of the denture base so its position becomes compatible with the existing occlusion, apart from allowing the displaced tissue to recover their original form.
Consequently, ridge relations are improved and this improvement facilitates the dentist's eventual relation registration procedures. It also facilitates the occlusal adjustments intraorally and extraorally, i.e., on an articulator. It may also be necessary to correct the extent of tissue coverage by the old denture base so all usable supporting tissue is included in the treatment. This correction can easily be achieved by use of one of the resin border-molding materials combined with a tissue conditioner.
Good nutrition: A good nutritional program must be emphasized for each edentulous patient. This program is especially important for the geriatric patient whose metabolic and masticatory efficiency have decreased.
Conditioning the patient's musculature: The use of jaw exercises can permit relaxation of the muscles of mastication and strengthen their coordination as well as help prepare the patient psychologically for the prosthetic service. If at the initial appointment the dentist observes that the patient responds with difficulty to instructions of relaxation and coordinated mandibular movements, a program of mandibular exercises may be prescribed. Such a program may be beneficial and the subsequent clinical appointment stages of registration of jaw relations facilitated.
SURGICAL METHODS Frequently, certain conditions of the denture bearing tissues require edentulous patients to be treated surgically. These conditions are the result of unfavorable morphologic variations of the denture bearing area, or more commonly may follow long term wear of ill-fitting dentures.
Correcting conditions that preclude optimal prosthetic function ( Hyperplastic ridge, Epulis fissuratum, Papillomatosis.) The premise underscoring surgical intervention is that mobile tissues (e.g., a hyperplastic ridge), tissue that interfere with optimal seating of the denture (eg epulis), or tissues that readily harbor microorganisms (a papillomatosis are not conducive to firm healthy foundations for complete dentures. Whenever possible, these tissues should be rested, massaged, and / or treated with an antifungal agent prior to their surgical excision. If the patient's health precludes surgical intervention, the impression technique and design of the denture base have to be modified.
Frenular attachments and pendulous maxillary tuberosities. Frena, or fibrous bands of tissue attached to the bone of the mandible and maxillae, are frequently superficial to muscle attachments. If the frenum is close to the crest of the bony ridge, it may be difficult to obtain the ideal extension and border of the flange of the denture.This tissue can be removed surgically. Frena often become prominent as a result of reduction of the residual ridges. If muscle fibers are attached close to the crest of the ridge when the frenum is removed, they usually are detached and elevated or depressed to expose the amount of desired ridge height.
The frenectomy can be carried out before prosthetic treatment is begun, or it can be done at the time of denture insertion when the new denture can act as a surgical template. Pendulous fibrous maxillary tuberosities are frequently encountered. They occur unilaterally or bilaterally and may interfere with denture construction by excessive encroachment on or obliteration of the interarch space. Surgical excision is the treatment of choice, but occasionally maxillary bone must be removed. Care must be used to avoid opening into the maxillary sinus.
Bony prominences, undercuts, spiny ridges, and nonparallel bony ridges. Mandibular tori are usually removed to avoid undercuts and to make possible a border seal beyond them against the floor of the mouth. They generally occur so close to the floor of the mouth that a border seal cannot be made. On the other hand, maxillary tori are infrequently removed. Satisfactory dentures can be made over most of them.
The indications for the removal of maxillary tori are as follows: An extremely large torus that fills the palatal vault and prevents the formation of an adequately extended and stable maxillary denture. An under cut torus that traps food debris, causing a chronic inflammatory condition; surgical excision is necessary to create optimal oral hygiene. A torus that extends past the junction of the ard and soft palates and prevents the development of an adequate posterior palatal seal. One that causes the patient concern (because of a cancerphobia)
Bony exostoses may occur on both jaws but are more frequent on the buccal sides of the posterior maxillary segments. They may create discomfort if covered by a denture and usual