 Goals of a removable partial denture service are maximum patient comfort, minimum post-insertion adjustments, and an occlusal harmony between the denture and the remaining teeth in order to preserve the health of their surrounding structures. To achieve these goals, it is necessary to be able to accurately occlude the casts on which these dentures are to be fabricated. In some instances, there are sufficient teeth remaining so that opposing casts may be articulated without the aid of a jaw relation record. However, most all distal extension cases and some totally tooth-borne partial dentures require a maxillomandibular record for accurate articulation. The first requirement of an accurate maxillomandibular record is the construction of a sufficiently strong record base. It is especially important when the case has to be sent to the laboratory through the mail. Auto-polymerizing methyl methacrylate resin is a very satisfactory material. Undercuts in the stone cast are blocked out with wax to prevent scraping or breaking the cast when removing the base. Measure sufficient monomer for the case. Add the polymer to saturate the liquid. When saturation is achieved, mix the ingredients with a spatula. While awaiting the doughy stage, place a sheet of wet cellophane on a glass plate. A convenient frame can easily be made to facilitate shaping of the resin and obtaining the desired thickness of the base material. Place the doughy resin within the frame and cover with another sheet of wet cellophane. A glass plate is used to press the resin to the proper thickness. An alginate tinfoil substitute is painted on the stone cast to prevent the resin from adhering. Form the base over the cast, trimmed to the extension desired. Keep the base from contacting the lingual surfaces of the stone teeth. This prevents scoring or breaking teeth when removing the base. When the base hardens, trim to the outline desired. The second requirement of the Maxillomandibular record is the addition of the occlusion rim. Hard base plate wax is the material of choice. To assure good adherence of the occlusion rim to the base, a film of sticky wax is applied to the base. The occlusion rim is formed and looted to the resin base. The third requirement for a satisfactory Maxillomandibular record is that the base is stable. This means the base must be accurately adapted to the master cast. Zinc oxide eugenol impression paste or indicator gel are excellent stabilizing materials. Stabilizing the base should always be done after the wax occlusion rims have been added. Heat used to attach the rims can distort the base as well as the stabilizing material. Look the master cast in water to prevent the stabilizing material from sticking to the stone. Warm the indicator gel to bring it to a fluid state. Remove the cast from the water. Eliminate the excess water with a blast of air. The softened indicator gel is painted on the tissue side of the base and the base is firmly seated on the moistened cast. Return the cast with base to the water for chilling the gel, the gross excess. The stabilized base is readily removed from the cast. Any indicator gel in an undercut area shears off without damaging the cast. The stabilized base with occlusion rims is ready for the dentist to proceed with recording centric occlusion. An alternate method of making a record base is to use shellac base plate material. For sufficient strength it is necessary to reinforce the lingual bar portion with wire. This base plate material can be softened and folded over the wire. The occlusion rims are added and the base is stabilized on the master cast as was demonstrated with the acrylic resin base. At the time of registering centric occlusion, first check the interdigitation of the patient's teeth. Introduce the occlusion rims into the mouth and again check centric occlusion to determine if the rims are interfering with the patient's proper occlusal relation. Both rims and record base should be out of contact with the opposing arch. Trim as necessary. Cut notches in the occlusion rim to provide an index for the plaster recording medium. Notice the clearance between occlusion rims and opposing teeth. When plaster is used as the recording medium, there should be sufficient bulk of the plaster for strength. This is achieved by adequate clearance of the base and opposing arch. A mix of quick-setting impression plaster is made by the assistant. The fourth requirement for an acceptable maxillomandibular record is the use of a recording medium that is uniformly soft so that it will not displace the soft tissue supporting the base causing the occluding vertical dimension to be increased when the stone casts are occluded. The recording material then must also become hard so that it will not distort in handling. The plaster is placed on the occlusion rims. The record base is carried to the mouth and the patient is instructed and guided to close in centric occlusion. The plaster is set when the material remaining in the rubber bowl fractures cleanly. Trim the excess plaster so that only an index of the cusp tips remains. This is done to ensure complete seating of the opposing cast into the record. The finished record in the mouth to be certain the patient had closed in centric occlusion when the record was made. The casts are assembled in centric occlusion with the aid of the maxillomandibular record. While the patient is still at hand, compare the occlusion of the cast with the patient's occlusion, being sure all the artificial stone teeth meet in the same relation as the natural teeth. If there is a discrepancy, one or both of the stone casts may be inaccurate. If the record checks, the case can be accurately mounted in an articulator by the laboratory technicians. Low fusing modeling plastic which can be uniformly softened also meets the requirements of a material for recording jaw relations. It is not necessary to index the wax occlusion rim since the modeling plastic fuses with the wax and will not break loose. Centric occlusion is recorded, being certain the patient's remaining natural teeth occlude correctly. If on inspection of the record, there is any evidence of the wax occlusion rim showing through the recording medium, remake the record after relieving the area in which the penetration occurred, trim the modeling plastic and recheck the finished record in the patient's mouth. Again, before dismissing the patient, assemble the cast with the aid of the record and compare with the patient's occlusion. If the operator desires to try in the metal framework before finishing the case, the casting may be used to carry the record base and occlusion rims. The procedure of using the framework to support the record base is often necessary in extensive removable partial denture cases where it is not possible to maintain an accurate relation of a record base to the remaining teeth. When the framework is used in conjunction with recording centric occlusion, be certain that none of the elements of the casting are interfering with the patient's bringing his teeth together and introducing an error into the record. This record can be made with either quick-setting plaster or low-fusing modeling plastic. Adherence to the procedure shown will result in achieving the goals of patient comfort, minimum adjustment, occlusal harmony, and preservation of the remaining tissues.