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Precision-formed polyethylene implants for correction of mandibular contour
Precision-Formed Polyethylene Implants for Correction of Mandibular Contour BURKE B. SHEVICK,D.D.S., M.D., Los A)2geles, California
likely to share tiffs view. Even small grafts taken from tile ilium create postoperative discomfort out of proportion to the contour defect that is being repaired. Another inherent fault of autogenous bone is evidenced by the fact that some grafts of this material which were inserted by the author four to five years ago have shown a small but noticeable &crease in size due to absorption. This clinical finding, which is supported by the reports of other investlgators, t should not be surprising since it has long been known that bone responds like muscle to physiologic stress and will be absorbed when it fails to serve a physiologic need. Controversy still exists regarding the permanence of this type of graft; however, it seems probable that in time a considerable number of autogenous onlay bone grafts will share the fate of preserved cartilage implants. The final reason for discontinuing autogenous bone onlay grafts is the waste of time and bone involved in the shaping of the outside and inside surfaces of the graft at the operating table. In view of these difficulties with bone and cartilage, attention has been focused from time to time on plastic substitutes. Among the more promising of the newer plastics is polyethylene, which was first used in neurosurgery by Ingraham, AIexander and hhtson, 2 and in plastic surgery by Rubin, Robertson and Shapiro. 3 However, like the biologic materials, polyethylene had to be shaped at the operating table under very adverse conditions. When the polyethylene was finally inserted, it demonstrated the same mechanical disadvantages that frequently were encountered with the biologic materials (rocking, displacement, dead space, obliteration of the gingivolabial fold and poor continuity of the margins of the graft
nls paper describes a method to form prepolyethylene implants to correct mandibular contour and reveals successful results achieved in twenty cases during the past fifteen months. These polyethylene implants were used in cases of microgenia, without malocclusion, as a supplement to other surgical procedures intended to bring the mandible forward, and in certain cases of micrognathia with malocclusion in which surgical advancement of the mandible was not indicated because of the nature of the malocclusion and d_eformity. In all these conditions the implants not only restored normal contour but also increased the support of the advanced soft tissues over the mandible. This enabled the lips to meet more easily, and as a result speech was improved and mouth-breathing reduced. Although many defects of the face and skull are best repaired with bone or cartilage, these biologic materials often produce indifferent results in some of these deformities. For example, in the past, mandibular contour deformities were corrected by onlay grafts of cartilage or bone. These grafts, however, have since been found to suffer from serious deficiencies. Preserved cartilage, for instance, fails to become fully immobilized and is often absorbed. Autogenous cartilage tends to curl after it is transplanted. Moreover, the donor area causes the patient considerable pain and disability. In like manner, autogenous bone suffers from disadvantages which have led to its discontinuance for mandibular onlay grafts. One of these disadvantages is that removal of the bone from the ilium results in considerable morbidity. Although many authors tend to minimize the importance of this effect, a patient who cannot walk for ten to fourteen days after removal of a full-thickness section of his ilium is not
T cision
American Journal oJ Surgery. Volume 92. October. z9~6
538
Correction of Mandibular Contour with tile surface of the mandible). How these disadvantages were finally overcome will be described fulIy in this report. POLYETHYLENE
The properties of polyethylene have been covered in detail by other investigators. This plastic substance meets the essential requirements, as listed by Clarke et al., 4 of a synthetic material that can be used for implants. Especially desirable is polyethylene's thermoplastic property which enables tile operator to shape the material to any desired form by compression or injection-molding. Reports by a number of investigators indicate that chemically pure polyethylene is noncarcinogenic. In the work of Rubin 5 and Clarke et al. 4 polyethylene implants were buried in humans and in laboratory animals for periods up to three years. After microscopic examination of biopsies, they found that the cellular and vascular response to the implant was nil. Gordo# adds that to date there has not been a single recorded instance of malignancy developing in a human being as a result of a plastic having been buried in the tissue. Gordon's observation is significant in view of the countless numbers of nylon sutures buried in humans during the past two decades. CONSTRUCTION O F MANDIBULAR PRECISION POLYETHYLENE IMPLANTS
Exposure of Mandible. Tile patient is seated in a chair equipped with a head rest. Using local anesthesia, the operator incises the interdent/d papilIas from first molar to first molar. Bilateral vertical incisions are made through the gingivaI mucosa from the interproximal space in front of the first molars to the inferior border of the mandible. With a periosteaI elevator, the soft tissues, including the periosteum, overlying the mandible between the vertical incisions, are reflected downward from the gingival margin until tlle inferior border of the mandible is freely exposed. In the process the mental neurovascular bundles are also easily exposed. They are dissected so that they will lie flat against the mandible when the impression is taken. (Fig. l.) Negatire Impression. An impression of the exposed mandible is made with Kerr's impression compound, a dental material used for taking impressions of the soft and hard tissues of the mouth. (Literature describing the physi539
FIG. I. Exposure of anterior surface of mandible and neurovascular bundles.
cal and working properties of this material can be obtained from any dental supply house.) After the impression is taken, the mueosa is tacked back into place with several sutures and a compression dressing is applied to the chin for twenty-four hours. Positive Impression. The positive impression, or cast, of the mandible is obtained by filling the negative with dental stone. This east is retained for reference; a duplicate cast is made for Working purposes. (Fig. 2A and B). On the duplicate cast the mental neurovaseular bundles, which extend from the mental foramen to the inferior border of the mandible, are trimmed away. (A sectional impression extending under the mental nerves obviates the need for this trimming and increases the accuracy of the cast.) Wax Model. Using dental wax, the operator now sculptures a model of the desired implant on the cast. (Fig. 2C.) Feathered extensions above and below the mental nerve will not only establish the continuity of the margins of tile implant to the surface of the mandible but also will enhance retention of the implant. Cephalometric x-rays and tracings should be made as they are very important in determining the shape and dimensions of the model. Formation of hnplant. The wax model is invested in dental stone. The two halves of the
Shevick of the teeth. Through a submandibular incision the soft tissues, including the perlosteum, are elevated. The mental neurovascular bundles are exposed. It may be necessary to make a vertical midline incision through the relatively inelastic band-like periosteum to prevent it from pulling the soft tissues upward and thus creating h double chin effect. The implant is now inserted so that tile lateral extensions of one end embrace the mental nerve and the entire implant is carried slightly laterally. The other end is elevated and the implant is brought back to the midline where it should seat firmly. The subcutaneous tissues are closed with fine chromic catgut, and the skin is closed with fine silk suture. An elastoplast compressive dressing is applied for several days. COMMENT
At first glance the construction of precision implants that require impressions, casts, models and molds may seem involved. Actually the procedure is very simple, even for an operator inexperienced in tlle use of dental materials. There are three steps: (I) secure tile impression; (2) sculpture the wax; and (3) insert tile implant. Most dental laboratories are equipped with an injection:molding machine, and for a "nominal charge will construct tile casts, invest the wax model and inject the polyethylene.
Fla. 2. A and B, positive impressions or casts of mandible oriented by cephalometric x-rays. C, wax model of implant. D and E, polyethylene implants.
mold a r e separated and tlle wax is removed. The implant may then be formed either by compression or injection-molding. When tlle implant is compression-molded, the empty mold is filled with polyeth3"lene granules and tile implant is formed by the application of heat and pressure. This method is satisfactory with small implants; but because it produces air bubble defects in large implants, it has been abandoned in favor of tile injection method which uniformly gives a smooth, satisfactory replica of the wax model. In the injection method a z/~ inch hole is drilled from the top of the investing flask to the mold, and the molten polyethylene is then torced through this sprue into the mold. The polyethylene should be heated to 300°F. before injection but the mold should remain at room temperature. After the formed implant is recovered, it is trimmed and multiple holes are drilled to permit connective tissue ingrowth which will provide additional fixation of tile implant to the mandible. (Fig. 2D and E.) Insertio;l of hnplant. The insertion of the implant is delayed one month to permit firm healing of tile gingiva to the cervical margins
ADVANTAGES OF MANDIBULAR PRECISIONFORMED POLYETHYLENE IMPLANTS
Precision-formed p o l y e t h y l e n e has been found to be the method and material of choice for mandibular implants for the following reasons: I. Intraoral exposure of the symphysis and mental areas of the mandible for the impression is a brief office procedure. The slight to moderate postoperative edema, lasting twenty-four to thirty-six hours, does not interfere with the patient's routine activity. 2. The operating time is reduced to a minimum since the implant is constructed in tile laboratory instead of in the operating room, as is the case with autogenous grafts. 3- The wax model may be leisurely sculptured in any shape or design. 4. Contact between the inner surface of the implant and the outer surface of the mandible is intimate and precise. This results in: (I) 540
Correction of Mandibular Contour
•
Nx
\
-
! i 3A
\
•.
)
/ ::2a
3B
!
-i?; ',:i'\,
3C
3D
FIG. 3- Micrognathla with malocclusion despite prolonged orthodontic treatment. Surgical advancement of mandible not indicated because of nature of malocclusion and deformity. Mandibular contour corrected with precision polyethylene implant. A and B, preoperative front and profile views. C and D, postoperative results.
absence of infection-producing dead space and serum; and (2) firm seating, so that even on the laboratory cast the implant is difficult to dislodge by any forward, vertical or lateral force. 5- The margins of the implant are feathered so that most patients cannot detect by palpation where the implant ends and the mandible
begins. Many patients volunteered the statement: " T h e chin feels like my own"; by way of contrast, autogenous grafts often feel to the patient like an afterthought of nature. 6. The gingivobuccal and gingivolabial folds are preserved because the feathered margin of the polyethylene implant extends upward 54i
Shevick
4A
4B
4C
4D
FIG. 4. A and B, preoperative front and profile views of mandibular contour defect. C and D, postoperative views of defect corrected with precision polyethylene implant. Rhinoplasty enhanced final result.
under the gingival xnucosa instead of displacing it, as frequently oceurs with large onlay grafts. 7. In the rare case of infection the implant is easily removed and reinserted at a later date. 8. In this method there is little danger of entering the oral cavity while preparing the bed for the reception of the implant. Since the operator may easily measure the vertical distance from the inferior margin of tile mandible to tile gingival margin on the cast or implant,
he can locate the tip of his periosteal elevator at all times. RESULTS
During the past fifteen months, precisionformed polyethylene mandibuIar implants have been used in twenty eases, with gratifying results. Figures 3 to 5 show typical results in three unselected eases. 0nly two complications, occurred in this 542
Correction of M a n d i b u l a r C o n t o u r
5A
5B
~C
5D
FIG. 5. A and B, preoperative front and profile views of mandibular contour defect. C and D, postoperative views of defect corrected with precision polyethylene implant. Rhinoplasty enhanced final result.
series of twenty cases. In one case a.postoperarive infection forced the removal of the implant, but the implant was successfully reinserted after the infection subsided. In the second case tile operator overextended the inferior margin of the implant. The submandibular incision was reopened several months later and the excess polyethylene was easily removed with a scalpel. At this time it was observed that the implant was enclosed in a smooth, thin envelope of fibrous tissue with
colunms of connective tissue growing through tile drill holes. The implant was fixed so firmly that it could have been removed only with considerable difficulty. SUMMARY AND CONCLUSIONS Because of increasing dissatisfaction with the unpredictable behavior of biologic grafts, as well as with the morbidity caused by the donor site, a simple method has been developed to form precision polyethylene implants. 543
Shevick These implants can be constructed in any desired shape. When introduced with strict sterile technic, they are received kindly by the tissues, with little or no reaction. They will seat firmly and resist displacement. Detection of the implant by palpation is difficult. Precision-formed polyethylene implants were used during the past fifteen months to correct mandibular contour in twenty cases of microgenia and micrognathia. The results to date have been far superior to those of former cases in which the same defect was corrected with autogenous illac bone and cartilage as well as preserved cartilage.
REFERENCES I. PEEa, L. A. Autogenous bone transplants. Plast. e" Reconstruct. Surg., i ." 56, 1954. 2. INGRAItAM,F. D., ALEXANDER,E., JR. and ~IATSON, D. D. PoIyethylene. d. A. 3I. A., 135: 82, 1947. 3- RUBIN, L., ROBEnTSOS, G. V¢. and StIAPIRO, R. N. Polyethylene in reconstructive surgery. Plast. ¢~ ReconStruct. Surg., 5:586, 19484. CLARKE,E. G. C., 17|ICK.MAN,J., COLLINS,D. H. and SCALES, J. T. Discussion on metals and synthetic materials in relation to tissues. Proc. Roy. Soc. A[ed., 46: 64t, x953. 5- RUI~IN, L. R. PolyethyIenc~-a three year study. Plast. o" Reconstruct. Surg., I: 13 I, 1951. 6. GoRoox, S. Subluxation of the temporomandibular joint. Plast. e~ Reconstruct. Surg., I : 57, 1955.
®
THE best therapy for rectal prolapse is a suitable operation, but occasionally the patient is too elderly or weak or refilses radical surgery. In these latter instances perircctal injections of a sclerosing solution will give satisfactory results. Maintenance of a tube in the rectum is part of the technic. It might be well to attempt treatment of some cases of rectal prolapse by the injection method; if a time comes when we are temporarily without hospital facilities because of fire, etc., we will be very glad that we acquired some experience with the injection treatment of these and similar lesions. (Richard A. Leonardo, M.D.)
544
likely to share tiffs view. Even small grafts taken from tile ilium create postoperative discomfort out of proportion to the contour defect that is being repaired. Another inherent fault of autogenous bone is evidenced by the fact that some grafts of this material which were inserted by the author four to five years ago have shown a small but noticeable &crease in size due to absorption. This clinical finding, which is supported by the reports of other investlgators, t should not be surprising since it has long been known that bone responds like muscle to physiologic stress and will be absorbed when it fails to serve a physiologic need. Controversy still exists regarding the permanence of this type of graft; however, it seems probable that in time a considerable number of autogenous onlay bone grafts will share the fate of preserved cartilage implants. The final reason for discontinuing autogenous bone onlay grafts is the waste of time and bone involved in the shaping of the outside and inside surfaces of the graft at the operating table. In view of these difficulties with bone and cartilage, attention has been focused from time to time on plastic substitutes. Among the more promising of the newer plastics is polyethylene, which was first used in neurosurgery by Ingraham, AIexander and hhtson, 2 and in plastic surgery by Rubin, Robertson and Shapiro. 3 However, like the biologic materials, polyethylene had to be shaped at the operating table under very adverse conditions. When the polyethylene was finally inserted, it demonstrated the same mechanical disadvantages that frequently were encountered with the biologic materials (rocking, displacement, dead space, obliteration of the gingivolabial fold and poor continuity of the margins of the graft
nls paper describes a method to form prepolyethylene implants to correct mandibular contour and reveals successful results achieved in twenty cases during the past fifteen months. These polyethylene implants were used in cases of microgenia, without malocclusion, as a supplement to other surgical procedures intended to bring the mandible forward, and in certain cases of micrognathia with malocclusion in which surgical advancement of the mandible was not indicated because of the nature of the malocclusion and d_eformity. In all these conditions the implants not only restored normal contour but also increased the support of the advanced soft tissues over the mandible. This enabled the lips to meet more easily, and as a result speech was improved and mouth-breathing reduced. Although many defects of the face and skull are best repaired with bone or cartilage, these biologic materials often produce indifferent results in some of these deformities. For example, in the past, mandibular contour deformities were corrected by onlay grafts of cartilage or bone. These grafts, however, have since been found to suffer from serious deficiencies. Preserved cartilage, for instance, fails to become fully immobilized and is often absorbed. Autogenous cartilage tends to curl after it is transplanted. Moreover, the donor area causes the patient considerable pain and disability. In like manner, autogenous bone suffers from disadvantages which have led to its discontinuance for mandibular onlay grafts. One of these disadvantages is that removal of the bone from the ilium results in considerable morbidity. Although many authors tend to minimize the importance of this effect, a patient who cannot walk for ten to fourteen days after removal of a full-thickness section of his ilium is not
T cision
American Journal oJ Surgery. Volume 92. October. z9~6
538
Correction of Mandibular Contour with tile surface of the mandible). How these disadvantages were finally overcome will be described fulIy in this report. POLYETHYLENE
The properties of polyethylene have been covered in detail by other investigators. This plastic substance meets the essential requirements, as listed by Clarke et al., 4 of a synthetic material that can be used for implants. Especially desirable is polyethylene's thermoplastic property which enables tile operator to shape the material to any desired form by compression or injection-molding. Reports by a number of investigators indicate that chemically pure polyethylene is noncarcinogenic. In the work of Rubin 5 and Clarke et al. 4 polyethylene implants were buried in humans and in laboratory animals for periods up to three years. After microscopic examination of biopsies, they found that the cellular and vascular response to the implant was nil. Gordo# adds that to date there has not been a single recorded instance of malignancy developing in a human being as a result of a plastic having been buried in the tissue. Gordon's observation is significant in view of the countless numbers of nylon sutures buried in humans during the past two decades. CONSTRUCTION O F MANDIBULAR PRECISION POLYETHYLENE IMPLANTS
Exposure of Mandible. Tile patient is seated in a chair equipped with a head rest. Using local anesthesia, the operator incises the interdent/d papilIas from first molar to first molar. Bilateral vertical incisions are made through the gingivaI mucosa from the interproximal space in front of the first molars to the inferior border of the mandible. With a periosteaI elevator, the soft tissues, including the periosteum, overlying the mandible between the vertical incisions, are reflected downward from the gingival margin until tlle inferior border of the mandible is freely exposed. In the process the mental neurovascular bundles are also easily exposed. They are dissected so that they will lie flat against the mandible when the impression is taken. (Fig. l.) Negatire Impression. An impression of the exposed mandible is made with Kerr's impression compound, a dental material used for taking impressions of the soft and hard tissues of the mouth. (Literature describing the physi539
FIG. I. Exposure of anterior surface of mandible and neurovascular bundles.
cal and working properties of this material can be obtained from any dental supply house.) After the impression is taken, the mueosa is tacked back into place with several sutures and a compression dressing is applied to the chin for twenty-four hours. Positive Impression. The positive impression, or cast, of the mandible is obtained by filling the negative with dental stone. This east is retained for reference; a duplicate cast is made for Working purposes. (Fig. 2A and B). On the duplicate cast the mental neurovaseular bundles, which extend from the mental foramen to the inferior border of the mandible, are trimmed away. (A sectional impression extending under the mental nerves obviates the need for this trimming and increases the accuracy of the cast.) Wax Model. Using dental wax, the operator now sculptures a model of the desired implant on the cast. (Fig. 2C.) Feathered extensions above and below the mental nerve will not only establish the continuity of the margins of tile implant to the surface of the mandible but also will enhance retention of the implant. Cephalometric x-rays and tracings should be made as they are very important in determining the shape and dimensions of the model. Formation of hnplant. The wax model is invested in dental stone. The two halves of the
Shevick of the teeth. Through a submandibular incision the soft tissues, including the perlosteum, are elevated. The mental neurovascular bundles are exposed. It may be necessary to make a vertical midline incision through the relatively inelastic band-like periosteum to prevent it from pulling the soft tissues upward and thus creating h double chin effect. The implant is now inserted so that tile lateral extensions of one end embrace the mental nerve and the entire implant is carried slightly laterally. The other end is elevated and the implant is brought back to the midline where it should seat firmly. The subcutaneous tissues are closed with fine chromic catgut, and the skin is closed with fine silk suture. An elastoplast compressive dressing is applied for several days. COMMENT
At first glance the construction of precision implants that require impressions, casts, models and molds may seem involved. Actually the procedure is very simple, even for an operator inexperienced in tlle use of dental materials. There are three steps: (I) secure tile impression; (2) sculpture the wax; and (3) insert tile implant. Most dental laboratories are equipped with an injection:molding machine, and for a "nominal charge will construct tile casts, invest the wax model and inject the polyethylene.
Fla. 2. A and B, positive impressions or casts of mandible oriented by cephalometric x-rays. C, wax model of implant. D and E, polyethylene implants.
mold a r e separated and tlle wax is removed. The implant may then be formed either by compression or injection-molding. When tlle implant is compression-molded, the empty mold is filled with polyeth3"lene granules and tile implant is formed by the application of heat and pressure. This method is satisfactory with small implants; but because it produces air bubble defects in large implants, it has been abandoned in favor of tile injection method which uniformly gives a smooth, satisfactory replica of the wax model. In the injection method a z/~ inch hole is drilled from the top of the investing flask to the mold, and the molten polyethylene is then torced through this sprue into the mold. The polyethylene should be heated to 300°F. before injection but the mold should remain at room temperature. After the formed implant is recovered, it is trimmed and multiple holes are drilled to permit connective tissue ingrowth which will provide additional fixation of tile implant to the mandible. (Fig. 2D and E.) Insertio;l of hnplant. The insertion of the implant is delayed one month to permit firm healing of tile gingiva to the cervical margins
ADVANTAGES OF MANDIBULAR PRECISIONFORMED POLYETHYLENE IMPLANTS
Precision-formed p o l y e t h y l e n e has been found to be the method and material of choice for mandibular implants for the following reasons: I. Intraoral exposure of the symphysis and mental areas of the mandible for the impression is a brief office procedure. The slight to moderate postoperative edema, lasting twenty-four to thirty-six hours, does not interfere with the patient's routine activity. 2. The operating time is reduced to a minimum since the implant is constructed in tile laboratory instead of in the operating room, as is the case with autogenous grafts. 3- The wax model may be leisurely sculptured in any shape or design. 4. Contact between the inner surface of the implant and the outer surface of the mandible is intimate and precise. This results in: (I) 540
Correction of Mandibular Contour
•
Nx
\
-
! i 3A
\
•.
)
/ ::2a
3B
!
-i?; ',:i'\,
3C
3D
FIG. 3- Micrognathla with malocclusion despite prolonged orthodontic treatment. Surgical advancement of mandible not indicated because of nature of malocclusion and deformity. Mandibular contour corrected with precision polyethylene implant. A and B, preoperative front and profile views. C and D, postoperative results.
absence of infection-producing dead space and serum; and (2) firm seating, so that even on the laboratory cast the implant is difficult to dislodge by any forward, vertical or lateral force. 5- The margins of the implant are feathered so that most patients cannot detect by palpation where the implant ends and the mandible
begins. Many patients volunteered the statement: " T h e chin feels like my own"; by way of contrast, autogenous grafts often feel to the patient like an afterthought of nature. 6. The gingivobuccal and gingivolabial folds are preserved because the feathered margin of the polyethylene implant extends upward 54i
Shevick
4A
4B
4C
4D
FIG. 4. A and B, preoperative front and profile views of mandibular contour defect. C and D, postoperative views of defect corrected with precision polyethylene implant. Rhinoplasty enhanced final result.
under the gingival xnucosa instead of displacing it, as frequently oceurs with large onlay grafts. 7. In the rare case of infection the implant is easily removed and reinserted at a later date. 8. In this method there is little danger of entering the oral cavity while preparing the bed for the reception of the implant. Since the operator may easily measure the vertical distance from the inferior margin of tile mandible to tile gingival margin on the cast or implant,
he can locate the tip of his periosteal elevator at all times. RESULTS
During the past fifteen months, precisionformed polyethylene mandibuIar implants have been used in twenty eases, with gratifying results. Figures 3 to 5 show typical results in three unselected eases. 0nly two complications, occurred in this 542
Correction of M a n d i b u l a r C o n t o u r
5A
5B
~C
5D
FIG. 5. A and B, preoperative front and profile views of mandibular contour defect. C and D, postoperative views of defect corrected with precision polyethylene implant. Rhinoplasty enhanced final result.
series of twenty cases. In one case a.postoperarive infection forced the removal of the implant, but the implant was successfully reinserted after the infection subsided. In the second case tile operator overextended the inferior margin of the implant. The submandibular incision was reopened several months later and the excess polyethylene was easily removed with a scalpel. At this time it was observed that the implant was enclosed in a smooth, thin envelope of fibrous tissue with
colunms of connective tissue growing through tile drill holes. The implant was fixed so firmly that it could have been removed only with considerable difficulty. SUMMARY AND CONCLUSIONS Because of increasing dissatisfaction with the unpredictable behavior of biologic grafts, as well as with the morbidity caused by the donor site, a simple method has been developed to form precision polyethylene implants. 543
Shevick These implants can be constructed in any desired shape. When introduced with strict sterile technic, they are received kindly by the tissues, with little or no reaction. They will seat firmly and resist displacement. Detection of the implant by palpation is difficult. Precision-formed polyethylene implants were used during the past fifteen months to correct mandibular contour in twenty cases of microgenia and micrognathia. The results to date have been far superior to those of former cases in which the same defect was corrected with autogenous illac bone and cartilage as well as preserved cartilage.
REFERENCES I. PEEa, L. A. Autogenous bone transplants. Plast. e" Reconstruct. Surg., i ." 56, 1954. 2. INGRAItAM,F. D., ALEXANDER,E., JR. and ~IATSON, D. D. PoIyethylene. d. A. 3I. A., 135: 82, 1947. 3- RUBIN, L., ROBEnTSOS, G. V¢. and StIAPIRO, R. N. Polyethylene in reconstructive surgery. Plast. ¢~ ReconStruct. Surg., 5:586, 19484. CLARKE,E. G. C., 17|ICK.MAN,J., COLLINS,D. H. and SCALES, J. T. Discussion on metals and synthetic materials in relation to tissues. Proc. Roy. Soc. A[ed., 46: 64t, x953. 5- RUI~IN, L. R. PolyethyIenc~-a three year study. Plast. o" Reconstruct. Surg., I: 13 I, 1951. 6. GoRoox, S. Subluxation of the temporomandibular joint. Plast. e~ Reconstruct. Surg., I : 57, 1955.
®
THE best therapy for rectal prolapse is a suitable operation, but occasionally the patient is too elderly or weak or refilses radical surgery. In these latter instances perircctal injections of a sclerosing solution will give satisfactory results. Maintenance of a tube in the rectum is part of the technic. It might be well to attempt treatment of some cases of rectal prolapse by the injection method; if a time comes when we are temporarily without hospital facilities because of fire, etc., we will be very glad that we acquired some experience with the injection treatment of these and similar lesions. (Richard A. Leonardo, M.D.)
544