Proper Contour Research Articles

Technique of splint contouring in resected edentulous mandibular reconstruction

Establishing the form of a supportive splint used in the surgical reconstructive treatment is discussed. The various aspects of the proper contouring of a splint for better position and support of remaining mandibular resected segments are presented.

TITANIUM IN CRANIOPLASTY.

The substances most commonly used in the repair of defects of the skull are autogenous bone, sheet tantalum, and plastics of various kinds. All have certain disadvantages. Bone, whether from rib or iliac crest, is difficult to shape into the proper contours; moreover, even autogenous bone grafts sometimes fail to unite, and may then be absorbed. Tantalum, in many ways a satisfactory alloplastic material, is impervious to diagnostic roentgen rays and this can be inconvenient when neuroradiological investigation is needed later. Zirconium, which was recommended for cranioplasty and other purposes by Bates et al., 1 apparently has the same disadvantage, although it is considerably lighter than tantalum. The plastics now in use in this country are chiefly of the acrylic group, and with careful technique these substances give good cosmetic results. However, there has been at least one report of traumatic fracture of a plastic insert, 4 and experiment has shown that an acrylic plate must be at least as thick as the skull if it is to give comparable protection; when the skull is thin, it is indeed quite difficult to mould a plate that will be strong enough, yet not palpable subcutaneously. Titanium, a light (atomic No. ~) metal, is frequently used for implants in orthopaedic surgery. As a material for cranioplasty, it has certain advantages which have appeared to justify its use, though it is by no means an ideal substance. It is well tolerated by the tissues; 3 recent spectrographic studies 2 show that, like vitaltium, a titanium implant undergoes very slight electro

Selecting facings for pontics

The five porcelain facings that are most commonly used in fixed prosthesis have been reviewed. The use of porcelain facings in combination with gold alloy backings is encouraged. Emphasis is placed on attaining the optimal biomechanical design. The reverse pin facing can be adapted to the greatest number of situations, followed by the long pin facing. Regardless of the facing used, the proper contour and form of the entire pontic must be developed.

The use of metal prostheses following anterior mandibulectomy and neck dissection for carcinoma of the oral cavity

Abstract Four different types of stainless steel prostheses were used to stabilize the cut ends of the mandible in thirty-nine patients undergoing anterior mandibulectomy in conjunction with resection of lesions of the oral cavity. It was necessary to remove twenty-four of these prostheses, the majority within the first six months, because of slight absorption around the points of fixation, pain, discomfort and partial extrusion. A Kirschner wire cut and bent to the proper contour and inserted into the transected ends of the mandible has been adopted by our service as the prosthesis of choice. This provides adequate fixation, ease of insertion and ease of removal. The third advantage is important, inasmuch as the majority of prostheses must be removed. Sufficient fibrosis and fixation of tissues developed during the temporary stabilization, and reasonably good function and facial contour were maintained.

The use of metal prostheses following anterior mandibulectomy and neck dissection for carcinoma of the oral cavity

Four different types of stainless steel prostheses were used to stabilize the cut ends of the mandible in thirty-nine patients undergoing anterior mandibulectomy in conjunction with resection of lesions of the oral cavity. It was necessary to remove twenty-four of these prostheses, the majority within the first six months, because of slight absorption around the points of fixation, pain, discomfort and partial extrusion. A Kirschner wire cut and bent to the proper contour and inserted into the transected ends of the mandible has been adopted by our service as the prosthesis of choice. This provides adequate fixation, ease of insertion and ease of removal. The third advantage is important, inasmuch as the majority of prostheses must be removed. Sufficient fibrosis and fixation of tissues developed during the temporary stabilization, and reasonably good function and facial contour were maintained.

The Porcelain Jacket Crown / Its Usefulness in Removable Bridgework

THE porcelain jacket crown has rendered wonderful service in raising the status of our profes­ sion. When indicated, it makes a restoration that is almost lifelike in ap­ pearance, comfort, durability and compatibility with the adjoining and underlying living tissues. In many of these respects, it affords a striking con­ trast to the old-fashioned gold shell crown. T o follow the first of the two pos­ sible methods of construction, the in­ direct, we first prepare the tooth in the mouth and reproduce with an amalgam die. Plaster models are made, and the crown is constructed to fit ex­ actly the amalgam die and to conform with the plaster models. T o follow the direct method, we would make the crown on the prepared tooth in the mouth without the aid of the amalgam die and plaster models. T he indirect technic is recommended because it offers uniformly better results. There are two types of the all-por­ celain jacket, one known as the shoulder crown, the other the shoulderless, or, as it is sometimes called, the overlap crown. W ith the shoulder crown, the shoulder is cut around the neck of the tooth just below the free gum-margin. This shoulder is made at right angles to the long axis of the tooth and of as little depth as possible. T he jacket is made to finish flush with the outer mar­ gin of the shoulder and at the same time to restore the proper enamel contour at the gum margin. T he shoulderless, or overlap, crown eliminates the cutting of a shoulder, the porcelain tapering down to a fine edge beneath the gum line. T he advantages of the shoulderless over the shoulder crown may be sum­ marized as follows: (1 ) conservation of tooth structure; (2 ) lessening of the danger of subsequent pulp involvement; (3 ) reduction of pain in the prepar­ ation. There are, however, some ac­ companying disadvantages: (1 ) the im­ possibility of getting a perfect fit at the gum margin; (2 ) the danger of frac­ ture of the porcelain; (3 ) the difficulty of getting the correct anatomic resto­ ration at the gingival third. Taking a common clinical case, that of a lower bicuspid with a gold shell crown, we frequently notice that the gum margin has receded. After the removal of the gold crown, we usually find that the enamel has been destroyed; the tooth is free of the bite, and there may be decay or sensitiveness around the neck of the tooth. From an esthetic