kennedy class IV

different treatment options in kennedy class iv

1. Kennedy class IV partial dentures By MOHAMMAD AL-GHRAISI Assistant-lecture Misrata university

2. Management of classIV Definition: A single saddle lies entirely anterior to the abutments. This class has no modifications The length of the saddle may vary from a single tooth to include posterior teeth in both sides of the jaw. Such dentures are commonest in the maxillary arches. The most frequent mandibular anterior saddle denture is the one that replaces the four incisors lost through periodontal disease. May occur in childhood and adolescence.

3. Treatment options of classIV In children Spoon denture Modification of spoon denture In adults Short span Long span Single implant Implant supported fixed prosthesis Fixed bridge Composite bonded bridges RPD Implant supported fixed prosthesis RPD

4. The treatment of children Spoon denture The spoon denture is a mucosa-borne partial denture which is constructed either in acrylic resin or in cast metal The denture should cover a large area of the hard palate to overcome the problem of poor retention. It should also be preferably extended to junction between the hard and soft palate in order to: Obtain retention by physical means as adhesion. Obtain an adequate posterior palatal seal necessary for denture retension . Benefit from the upward pressure of the tongue causing seating of the denture against vertical displacement. The borders of denture should be 3-4 mm away from the gingival margin to avoid caries and gingivitis.

5. Modifications of spoon denture spoon denture could be modified to improve retention and stability in the following manner: 1. Spoon denture modified by use of Adams clasps The palatal plate is extended laterally above the survey line of the first molars. 2. T-shaped cobalt chromium denture The spoon dentures in the form of a combination of an anterior cast cobalt chromium base and posterior acrylic resin extension carrying an Adam crib clasp for providing retention

6. Factors affecting success of spoon dentures Nature of the mucosa the presence of firm mucosa of adequate thickness rather than thin mucosa that is usually encountered in children provides better denture retention. Form of the hard palate Large palate provides better retention by adhesion Palates with steep slopes offer more resistance to lateral forces and provide denture stability Use of anterior flange that helps to resist downward dispalcement of the restoration Degree of vertical overlap the presence of deep vertical overlap associated with a small horizontal overlap resulting due to partial edentulism induces stresses on the denture during incision.

7. Treatment of adult patients four lines of treatment are proposed for the treatment of unilateral bounded areas. These are: Implant supported prosthesis Fixed bridges RPD Composite bonded bridges

8. IMPLANT OPTION

9. Class IV skeleton design Class IV skeleton design is an alternative line of treatment to fixed bridge. It is indicated in the following conditions: Cases where marked bone resorption necessitates the addition of an anterior flange to restore esthetics and provides lip support. Patients who refuse extensive preparation required to prepare the abutments supporting the bridge. Cases having long, markedly curved edentulous span because this may add excessive stresses on abutments.

10. Generally two skeleton design were proposed: the first uses an anterior clasping system in the form of I bar clasp located on the canine and a re-enforcing circumferential aker clasp located on the first premolar. This clasping system has the disadvantage of placing excessive stresses on the canine and bad esthetics. The canines used should be strong and should have long well formed roots to resist torque. The second design uses a posterior clasping system in the form of an embrassure clasp or multiple clasp located as far posteriorly as possible. This system is more favorable because it provides more direct and indirect retention. It also esthetically more satisfactory and more hygienic. The canines are also saved from excessive torque placed on them.

11. The general design for posterior clasping system employed in either upper or lower classIV consist of : Denture base a combination metal-acrylic base is usually indicated to provide esthetics and to allow for future relining when bone resorption occurs . Supporting rests support is preferably provided by cingulum rests located on adequatley prepared rest seats on the canine teeth. Clasps embrassure or aker clasp located posteriorly preferably on the first molar teeth are used. The more posteriorly located the clasps the more will be the retention of the appliance.

12. Major connector for upper class IV , anterior plate or anteroposterior platal plate may be used For lower class IV, lingual bar connector is used. Indirect retainer indirect retention to counteract around the fulcrum axis is encountered by the rests of posterior clasps. Indirect retention to counteract displacement of upper dentures resulting fro heavy weight of the cast metal appliance is counteract by proper extension of the labial flange and by the labial flange designed to engage a soft tissue undercut