Louis J. Boucher

Posterior border movements of the human mandible

Abstract Needle point tracings were obtained from 12 conscious subjects. While these same subjects were under the influence of general anesthesia and curare, needle point tracings were again obtained. The condyles of the patients under anesthesia and curare could be moved further posteriorly than the conscious posterior border position.

Prosthetic restoration of a maxilla and associated structures

Abstract A technique for the fabrication of a prosthesis to replace an orbit and maxilla has been described. The special features of the technique are the use of a compressible spongelike material for the obturator. This material makes the difference between a fair and a good result. A seemingly complex prosthesis has been divided into four simple parts, which are retained in relation to each other by magnets and undercuts in the materials.

Can biting force be used as a criterion for registering vertical dimension

Abstract Boos designed an instrument for obtaining the vertical dimension of rest position. This instrument was based upon the premise that the greatest biting force is at the rest position. Results of various investigators arouse doubts as to whether this premise is correct. In our experiments no hyperbola-like curves were recorded. The use of the Bimeter is also limited because of the psychic influences of pain and apprehension. 8 *1 *The use of the Bimeter for determining vertical dimension was summarized by Jarabak

Limiting factors in posterior movements of mandibular condyles

Abstract It appears that neither the temporomandibular nor the capsular ligaments are responsible for limiting posterior border movements of the mandible. Further investigation of this problem is indicated.

INJECTED SILASTIC FOR TISSUE PROTECTION.

Abstract Four research projects were designed to study the reaction of the tissue to implanted plastic and silicones. The original purpose of this research was to provide information which could be useful in using a plastic sub-structure in implant dentures. These projects were briefly described and the results summarized. Because of the desirable physical properties of Silastic, it was a logical choice for ridge build-up procedures by the implantation technique. From these experiments evolved the injection method of ridge extension and tissue protection. This method involves the injection of a fluid, unvulcanized synthetic rubber under the tissues which is catalyzed to form a firm, soft cushion which in turn protects the oral tissues. Experiments to date indicate that this method is most effective when injected over sharp bony prominences like the genial tubercules, sharp mylohyoid and residual alveolar ridges and over mental foramina in severely resorbed ridges. Ridge build-up procedures are successful only to the amount of soft tissue available to receive the injected Silastic. Silastic has also been beneficial for those patients who present an anterior upper ridge with considerable hypertrophy and hyperplasia. Injections in this region have resulted in firmer gingival tissues and the final elimination of the build-up of inflammatory tissue and resultant hyperplasia. The use of implanted and injected Silastic as an aid to prosthodontic practice looks very promising at this time. Various methods and materials will require diversified and long-term clinical study. This report is published in the hope that it will stimulate more research in this field.

Injected silastic in ridge extension procedures

Abstract We postulate from our animal experiments thus far that modified Silastic RTV S-5392 is the material of choice (among those presently available) for injection in ridge extension procedures. The technique of injecting Silastic in ridge extension procedures in both animals and human experiments looks very promising at this time. Various methods and materials will require diversified and long-term clinical study. This is a preliminary report and is published in the hope that it will stimulate more research in this field.

Anatomy of the temporomandibular joint as it pertains to centric relation

Abstract Various experiments and reports which support or contradict the theory that the most retruded border position of the condyles is limited by muscles have been discussed.

Observations on arthrodial types of temporomandibular joints

V ARIOUS OPINIONS ARE HELD by different investigators as to the functional importance of the anatomic structures which take part in limiting retrusion of the mandible. Arstadl points out that in other joints, of the digits for example, limitation of motion is due to the joint capsule and re-enforcing ligaments. In the temporomandibular joint, the capsule is slack and flaccid, so much so that it is not injured when the joint is dislocated. The sphenomandibular and stylomandibular ligaments, by their position, cannot prevent the condyles from sliding dorsally. In 1933,2 Arstad maintained that the anterior part of the joint capsule supports the retruded position. In 1954,l however, he described some collateral capsular ligaments as being responsible for limited retrusion of the condyles. Steinhardt3 reported in 1934 that the external pterygoid muscle limits retrusion of the condyles. In 1957, however, Steinhardt4 agreed with Arstadl that the collateral capsular ligaments of the temporomandibular joint are responsible. He also said that the muscles are important but did not elaborate. Siche+a stated that one function of the external pterygoid muscle is to hold the condyle and disc against the posterior slope of the articular eminence while the teeth are in contact, Markowitz and Gerry? and other investigators state that the function of the external pterygoid muscles acting together is to cause protrusion of the mandible. The role muscles play in limiting retrusion of the condyles was contradicted by the work of Aprile and Sai.zar3 when they obtained symphyseal angle tracings from specimens with the joints intact but with the muscles removed. The work of PosseltQ also nullified the theory that muscles are the effecters which limit posterior retrusion of the condyles. Posselt obtained Gothic arch (stylus) tracings from anesthetized living persons under the influence of curare. Ferrein,lO Breuer,ll and ReeC reported that the retruded position of the condyles is held by the temporomandibular ligament. Kirk13 was of the opinion that the denture bears the main stress of mastication and prevents the backward thrust of the condyles. Robinson14 reported that the mandibular condyle in its most retruded position is not normally situated at the bottom of the mandibular fossa but is closer to the posterior part of the tuberculum articulare.

The nature of supporting tissues for complete dentures

Summary An understanding of the function and characteristics of the palatal mucosa is essential in denture fabrication. The oral problems of the aging edentulous patient are important to the dentist in determining the effects of tissue changes. Cellular alterations and mucosal changes can affect the adaptation of a prosthetic appliance. The role of the various denture base materials and the influence they may have upon the supporting tissues must be thoroughly understood if complete denture treatment is to be successful.

Internal nasal prosthesis

Abstract A case of traumatic deformity of the nose and premaxillae is presented. Because the patient refused extensive plastic reconstructions, a series of limited operative procedures were carried out to improve his airway and appearance. The basis for these improvements was the utilization of an internal nasal prosthesis.