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Hemorrhage After Endosseous Implant
bone and not woven bone. We believe that one can expose an implant prior to its final lamellar bone maturation, which is further remodeled throughout the func tional life of the implant. Even though Dr. Roberts may indicate that 18 months may be needed for some lamellar bone for mation, the bone implant interface is a dynamic one that will respond to forces placed upon it throughout the life of the implant. Therefore, we find it difficult to agree with Dr. Cliff that lamellar bone formation is the required end point before exposing an implant. Our clinical experiences have indicated that in the average indi vidual the exposure of an implant can occur between eight to 12 weeks after placement. Readers are appropriately cautioned that if they have a patient with extremely soft bone or a patient that requires a sur gical manipulation at the implant placement site combined with hydroxylapatite or autogeneous bone grafts, then a longer healing period can be used. We do not agree that waiting six months is required for the exposure of these implants. Our experiences with over 1,500 implants indicates that we __ can expose these jm implants in a shorter Jfr time. We believe Jr this clinical information and that derived from scientific studies do not “push the system.” ” In response to Dr. Podwika’s brief letter, there are several correc tions that must be made. The first is the error that he makes that the suc cess rate for implants drops drasti cally after two years. Obviously he is not familiar with the osseointegrated implant literature which sug gests that after two years the success rate of implants is much bet ter than that over the first two years when most implants, if they are
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going to be lost, fail. The Swedish experience, as well as ours, con firms that as time goes on an inte grated implant remains stable. We attempted to use life tables which indicate the survival of implants over a certain amount of time and report the number of implants in each interval. As indi cated in the study, the implants were placed between July, 1982 and February, 1989. As such, all of these implants can not be assumed to have been in place for five years; the title of the article is five-year observa tions and not five-year results. Apparently Dr. Podwika does not understand the life table concept or he would understand “what hap pened to the other 760 and the 95 percent success rate.” We suggest that he reread the caption under neath the life table to understand how it should be interpreted. The 27 HA coated IMZ implants were of a different design, and because of problems beyond our control, required custom made parts. Because of the extreme dif ferences in both stricture, design, and the parts, we believed it is more appropriate to record a homo geneous population of implants. We feel that The Journal and WWlNtylNMHHj^^^its authors have hpen insulted by ( jP ^ m B m his comments concerning “The Journal has been bought by manufacturers the implant....” We believe that the editors of The Journal used the upmost professionalism in refereeing this article. We have the utmost faith in the editorial staff of The Journal of the American Dental Association and we feel that Dr. Podwika’s state ments are inappropriate. John N. Kent, D.D.S. Boyd Professor and Head Department o f Oral and Maxillofacial Surgery
Michael S. Block Associate Professor Department o f Oral and Maxillofacial Surgery Louisiana State University
HEMORRHAGE AFTER ENDOSSEOUSIMPLANT
I am writing in reference to a recent article entitled “Life-threatening hemorrhage after placement of an endosseous implant: report of case,” by Dr. Gerald Laboda (November). There are several important issues I believe need to be addressed concerning this case report, which were not mentioned in the article. I would like to discuss them so that we may all benefit from what I suppose was a long day in Dr. Laboda’s practice. This complication of endosseous implants has been well docu mented and discussed by Mason and his colleagues in the surgical literature. They stated, as did Dr. Laboda, that it is caused by trauma to a branch of the lingual vessels. Mason reported that this bleeding may also occur in cases of mandibular fractures. By reviewing the patients’ surgi cal history, it is noticed that he has extensive peripheral vascular dis ease. The patient reports taking multiple medications daily, one of them being aspirin. A red flag must go up for every surgeon when this history is given. The patient has stated to you that he has a func tional platelet defect, acquired because of the aspirin use. One must also be aware of medications that contain aspirin, as well as non steroidal anti-inflammatory drugs, which have a similar affect on platelet function. This defect is a permanent one lasting the life span of the cell, which is eight to 10 days. Aspirin (acetylsalicyclic acid) acetylates the platelet cyclooxygenase system,
and thus decreases production of prostaglandin endoperoxide inter mediates of thromboxane A2that stimulates aggregation and release. During the primary response to tis sue and vessel injury, the platelets are W a unable to adhere together during ' aggregation and JnKÊk form the fibrin platelet plug. Even minor bleeding may continue for extreme periods of time without this platelet aggregation. The patient was reported to have had a normal coagulation study. In most hospitals this consists of check ing the patient’s prothrombin time and partial thromboplastin time (PT/PTT). These tests examine the intrinsic and extrinsic coagulation cascade in the system, and not the platelet function. One would need to perform a “bleeding time,” which tests the function of the platelets. It is reported that the patient’s general dentist was consulted with out any reference to his internist. For elective surgery the patient should have been taken off aspirin for ten days before surgery, after consulting with his physician. This would have allowed a healthy hematopoietic system to regenerate enough platelets to correct any functional defect. If it was not possible to stop the aspirin because of the patient’s medical condition, or in the case of emergency surgery, then it is rec ommended that the surgery be per formed in a hospital operating room where possible platelet trans fusion could have been made avail able if needed. In reading the hospital and oper ative management of the patient, I see no indication to contemplate a tracheostomy if the airway was controlled and maintained by the
24
endotracheal tube. Operatively I feel that the extraoral approach did not add any benefit to the surgery. In an edentulous mandible, the intraoral approach dissecting along the lingual plate would have pro vided adequate visualization, with out the added morbidity of a surgical scar and chance of damag ing the marginal mandibular branch of the facial nerve. It is unclear in the operative description who performed the surgery. Was it the author or the otolaryngologist? I find it difficult to understand the sentence in the first paragraph of the discussion... “rather than the inferior border itself was probably perforated.” At the time of the surgery wasn’t the mandible around the region of the implants thoroughly examined to find the exact area of bony perfora tion? This would have directed the surgeon to the region of soft tissue damage and hemorrhage. In the discussion, there was no reference suggesting a possible cor relation between the patient devel oping the hematoma and the use of aspirin. If the aspirin was not dis continued prior to surgery, it may have contributed to the bleeding if it jjflPMWRINMI had not been JF its actual jjr cause. M I believe that the relevance of this article is not in the fact that another compli- ^ ^ 1 cation of dental implants was reported. It lies in the importance of the need for all clinicians to take an accurate and thorough medical history and consult with our col leagues in order to treat our patients effectively, efficiently and safely. Stephen A. Chidyllo, D.D.S., M.D. Surgical Fellow University o f Illinois at Chicago
It is obvious from the article that
the Core-Vent Implants were not “well-positioned” in the mandible. The radiograph, although difficult to read as reprinted in the publica tion, shows the implants placed in the A and E positions (Misch-Judy classification). It shows the implants in place in an area of bone with extensive resorption as it transverses posteriorly to the body of the mandible. The anatomy of a resorbed mandible almost always presents an angulated trajectory because of resorptive bone loss from the buc cal and labial surfaces. It may be up to 45 degrees or more. Placing implants in a vertical direction to “parallel” them to each other in the canine-first premolar area (A and E positions) will almost always perfo rate the inferior lingual border of the mandible. The comment of “possible perfo ration” and “no more than 1 mm” perforation appears to be fallacious, since there was obviously more of a perforation than stated to sever the lingual artery. Unless proved other wise, the statement “a branch of the lingual or facial artery” is not justi fied as an etiological factor. An implant overlay on a preoperative panoramic H r radiograph does not reveal the trajectory of the bone. The postoperaW tive panoramic film looks MF great because it does not show the implant perforated W on the lingual side of the * mandible. A CT Scan (Denta Scan) of the mandible preoperatively would diagnosis the case properly. It would have revealed exactly the height, width and length of the available bone and more impor tantly, the trajectory of the bone where the implant was to be placed. A postoperative Denta Scan will almost certainly reveal the implants perforating through the
22
going to be lost, fail. The Swedish experience, as well as ours, con firms that as time goes on an inte grated implant remains stable. We attempted to use life tables which indicate the survival of implants over a certain amount of time and report the number of implants in each interval. As indi cated in the study, the implants were placed between July, 1982 and February, 1989. As such, all of these implants can not be assumed to have been in place for five years; the title of the article is five-year observa tions and not five-year results. Apparently Dr. Podwika does not understand the life table concept or he would understand “what hap pened to the other 760 and the 95 percent success rate.” We suggest that he reread the caption under neath the life table to understand how it should be interpreted. The 27 HA coated IMZ implants were of a different design, and because of problems beyond our control, required custom made parts. Because of the extreme dif ferences in both stricture, design, and the parts, we believed it is more appropriate to record a homo geneous population of implants. We feel that The Journal and WWlNtylNMHHj^^^its authors have hpen insulted by ( jP ^ m B m his comments concerning “The Journal has been bought by manufacturers the implant....” We believe that the editors of The Journal used the upmost professionalism in refereeing this article. We have the utmost faith in the editorial staff of The Journal of the American Dental Association and we feel that Dr. Podwika’s state ments are inappropriate. John N. Kent, D.D.S. Boyd Professor and Head Department o f Oral and Maxillofacial Surgery
Michael S. Block Associate Professor Department o f Oral and Maxillofacial Surgery Louisiana State University
HEMORRHAGE AFTER ENDOSSEOUSIMPLANT
I am writing in reference to a recent article entitled “Life-threatening hemorrhage after placement of an endosseous implant: report of case,” by Dr. Gerald Laboda (November). There are several important issues I believe need to be addressed concerning this case report, which were not mentioned in the article. I would like to discuss them so that we may all benefit from what I suppose was a long day in Dr. Laboda’s practice. This complication of endosseous implants has been well docu mented and discussed by Mason and his colleagues in the surgical literature. They stated, as did Dr. Laboda, that it is caused by trauma to a branch of the lingual vessels. Mason reported that this bleeding may also occur in cases of mandibular fractures. By reviewing the patients’ surgi cal history, it is noticed that he has extensive peripheral vascular dis ease. The patient reports taking multiple medications daily, one of them being aspirin. A red flag must go up for every surgeon when this history is given. The patient has stated to you that he has a func tional platelet defect, acquired because of the aspirin use. One must also be aware of medications that contain aspirin, as well as non steroidal anti-inflammatory drugs, which have a similar affect on platelet function. This defect is a permanent one lasting the life span of the cell, which is eight to 10 days. Aspirin (acetylsalicyclic acid) acetylates the platelet cyclooxygenase system,
and thus decreases production of prostaglandin endoperoxide inter mediates of thromboxane A2that stimulates aggregation and release. During the primary response to tis sue and vessel injury, the platelets are W a unable to adhere together during ' aggregation and JnKÊk form the fibrin platelet plug. Even minor bleeding may continue for extreme periods of time without this platelet aggregation. The patient was reported to have had a normal coagulation study. In most hospitals this consists of check ing the patient’s prothrombin time and partial thromboplastin time (PT/PTT). These tests examine the intrinsic and extrinsic coagulation cascade in the system, and not the platelet function. One would need to perform a “bleeding time,” which tests the function of the platelets. It is reported that the patient’s general dentist was consulted with out any reference to his internist. For elective surgery the patient should have been taken off aspirin for ten days before surgery, after consulting with his physician. This would have allowed a healthy hematopoietic system to regenerate enough platelets to correct any functional defect. If it was not possible to stop the aspirin because of the patient’s medical condition, or in the case of emergency surgery, then it is rec ommended that the surgery be per formed in a hospital operating room where possible platelet trans fusion could have been made avail able if needed. In reading the hospital and oper ative management of the patient, I see no indication to contemplate a tracheostomy if the airway was controlled and maintained by the
24
endotracheal tube. Operatively I feel that the extraoral approach did not add any benefit to the surgery. In an edentulous mandible, the intraoral approach dissecting along the lingual plate would have pro vided adequate visualization, with out the added morbidity of a surgical scar and chance of damag ing the marginal mandibular branch of the facial nerve. It is unclear in the operative description who performed the surgery. Was it the author or the otolaryngologist? I find it difficult to understand the sentence in the first paragraph of the discussion... “rather than the inferior border itself was probably perforated.” At the time of the surgery wasn’t the mandible around the region of the implants thoroughly examined to find the exact area of bony perfora tion? This would have directed the surgeon to the region of soft tissue damage and hemorrhage. In the discussion, there was no reference suggesting a possible cor relation between the patient devel oping the hematoma and the use of aspirin. If the aspirin was not dis continued prior to surgery, it may have contributed to the bleeding if it jjflPMWRINMI had not been JF its actual jjr cause. M I believe that the relevance of this article is not in the fact that another compli- ^ ^ 1 cation of dental implants was reported. It lies in the importance of the need for all clinicians to take an accurate and thorough medical history and consult with our col leagues in order to treat our patients effectively, efficiently and safely. Stephen A. Chidyllo, D.D.S., M.D. Surgical Fellow University o f Illinois at Chicago
It is obvious from the article that
the Core-Vent Implants were not “well-positioned” in the mandible. The radiograph, although difficult to read as reprinted in the publica tion, shows the implants placed in the A and E positions (Misch-Judy classification). It shows the implants in place in an area of bone with extensive resorption as it transverses posteriorly to the body of the mandible. The anatomy of a resorbed mandible almost always presents an angulated trajectory because of resorptive bone loss from the buc cal and labial surfaces. It may be up to 45 degrees or more. Placing implants in a vertical direction to “parallel” them to each other in the canine-first premolar area (A and E positions) will almost always perfo rate the inferior lingual border of the mandible. The comment of “possible perfo ration” and “no more than 1 mm” perforation appears to be fallacious, since there was obviously more of a perforation than stated to sever the lingual artery. Unless proved other wise, the statement “a branch of the lingual or facial artery” is not justi fied as an etiological factor. An implant overlay on a preoperative panoramic H r radiograph does not reveal the trajectory of the bone. The postoperaW tive panoramic film looks MF great because it does not show the implant perforated W on the lingual side of the * mandible. A CT Scan (Denta Scan) of the mandible preoperatively would diagnosis the case properly. It would have revealed exactly the height, width and length of the available bone and more impor tantly, the trajectory of the bone where the implant was to be placed. A postoperative Denta Scan will almost certainly reveal the implants perforating through the