Textbook of oral & maxillofacial surgery

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1 Textbook of Oral and Maxillofacial Surgery Gustav O Kruger (The C V Mosby Company, St Louis, Toronto, London, 1979) Fifth Edition To Simon P Hullihen, 1810-1857 The first oral surgeon in the United States Preface This text was written to provide a concise description of principles and procedures in each important aspect of oral and maxillofacial surgery in a logical sequence, as it may be presented to students in the lecture course. The book is designed to fit the needs of the undergraduate student, but general practitioners, residents, oral surgeons, and other specialists will also find it useful. Emphasis has been placed on the fundamentals of judgment and technique. Even if the reader does not perform all the procedures described, he or she should have a clear idea of what is done, how it is done, and why it is done. The first edition was published in 1959. In the four revisions since then considerable change in philosophy, materials, and technique reflects the progress that the specialty of oral surgery has achieved. The health sciences in general, and oral surgery in particular, have made rapid and substantial advances based on basic research, clinical investigation, and worldwide clinical experience. Comprehensive review has been undertaken in this fifth edition. Major revision has been completed in many chapters, and many new photographs and drawings have been added. I welcome two new authors in this edition, one writing on principles of surgery and the other on hemorrhage and shock. Both chapters have been rewritten completely. The contributors have been selected because of their competence in the field. Each has devoted his efforts to one chapter. It is to them that any credit for this work is due. Without exception, they have been generaous with their time and efforts. I should like to thank B. John Melloni, Director of Medical-Dental Communications, Georgetown University Medical Center, for his generous guidance and supervision of the art work. Peter Stone of his department made the new drawings and put together the photographs for this edition in a superb manner. He is a meticulous illustrator, a talented artist, and a most cooperative collaborator. Gustav O Kruger 2 Chapter 1 Principles of surgery H David Hall Oral surgery is unique among surgical specialties in that it identifies strongly with dentistry. This is a proper relationship since a thorough knowledge of dentistry is a prerequisite for the well-qualified oral surgeon. But oral surgery is no less a surgical specialty than urology, for example. The common link between oral surgery and other surgical specialties is that the same surgical principles apply to therapy. Thus the principles that guide the general surgeon in treating appendicitis are the same as those that guide the oral surgeon in treatment of an odontogenic cellulitis. The fact that details of application of surgical principles may differ to accommodate local peculiarities sometimes obscure this relationship. However, the casual observer may think that some surgical principles do not apply to a particular surgical specialty such as oral surgery. An example is the principle of asepsis, because aseptic technique clearly is different for abdominal operations and oral operations. Aseptic technique has been modified to take into account differences in the response of a wound in each area; the general principle of asepsis is the same. Thus the challenge for each surgical specialist is not only to know surgical principles but also to know how they apply to a particular area of interest. Asepsis Prior to the mid-nineteenth century, surgeons made no specific efforts to reduce bacterial contamination of the wound. Yet wounds often healed after primary closure. As hospitals became more prevalent, patients with septic conditions were housed with other patients, since isolation procedures had not been developed. With increased opportunities for wound contamination, especially from these patients, wound infection became commonplace. Even beforte Lister made his contribution to antisepsis, Semmelweis and O W Holmes observed that puerperal fever was spread from infected to uninfected parturient women in the obstetrical wards by their doctors. The simple act of washing hands between patients, thereby reducing the number of virulent bacteria introduced into wounds, greatly reduced puerperal sepsis. Although these doctors did not know what it was that caused the infections, they clearly understood the nature of the transfer. A few years later Pasteur developed the germ theory of disease. This concept provided a basis for understanding wound sepsis. Lister grasped the significance of Pasteur's work and began development of aseptic surgical technique. Even with modern aseptic surgical technique, some bacteria get into wounds. But wounds are able to tolerate a limited number of bacteria without becoming infected. Several factors determine the maximum number of bacteria that a wound will tolerate. One very important factor is local immunity, and this varies with the area of the body. The oral and maxillofacial region and perineum, for example, have a greater resistance to infection than other regions of the body. Relatively large numbers of indigenous bacteria can be introduced into oral or perineal wounds and rarely cause infection. This is fortunate since it is virtually impossible to reduce bacterial contamination in the mnouth or perineum to levels common for other areas of the body. The current aseptic techniques for the oral and maxillofacial area rely principally on prevention of wound contamination by foreign and especially more virulent bacteria. 3 There are also other factors that determine the maximum number of bacteria with which wounds can become contaminated before developing infection. The body's general resistance to infection is clearly an important factor. Diabetes is an example of a common condition in which there is an increase in susceptibility to infection. Other less common but by no means rare examples are suppression of immunity by corticosteroids or other drugs, leukemia, and uremia. Local wound factors also influence susceptibility to infection. Wound infection is more common after devitalization of tissue, as can occur with accidental injury or careless surgical technique. Thus although aseptic technique is an important factor in reducing wound infections, other factors also have an important influence on the problem. The surgeon who understands these interrelationships is able to make appropriate adjustments in patient management and maintain a low infection rate in most circumstances. Analytic Approach to Surgical Care One of the more important contributions to the care of the surgical patient was appreciation of the value of an analytical approach. The essence of an analytical approach to a clinical puzzle is separation of the various problems and establishment of the relationships of the individual problems to each other. The solution often is evident at this point, or a possible solution is suggested that can be tested. The first step in the analysis of any situation is to obtain accurate data. The traditional means of establishing these data is by historical, physical, and laboratory examination of the patient. Skill in application of examination technique is essential in order to obtain accurate data. For example, a common tendency of the less experienced clinician is to establish a tentative diagnosis early in the historical evaluation of a patient and then to ask leading questions in an effort to support the diagnosis. Open-ended questions would clearly provide more accurate information even if they might cause some discomfort to the clinician looking for support for an early impression. Similarly, a thorough, careful physical examination of a patient will often yield information missed by a more hurried, less orderly examination. Detection of a small sinus tract in the sulcus overlying a fracture site in a patient with delayed union is an easily missed but very important finding. In particularly difficult diagnostic problems, the more famous surgeons have been noted for the unhurried, careful, and thoughtful examinations they perform. In addition to being accurate, the information must also be pertinent. This aspect of patient evaluation probably requires the greatest amount of experience for perfection. With increased knowledge of a condition, one begins to recognize which information is particularly pertinent for its diagnosis and treatment. The practitioner can then probe the more relevant areas with greater care. For example, determining that a patient with bleeding from the gingival crevice recently began taking quinidine, which can cause thrombocytopenia, has greater significance in this patient than in a patient who has an infected tooth. Thus skill in patient evaluation requires not only a knowledge of the technique of evaluation but also a knowledge of specific conditions. Analysis of the information obtained from patient evaluation may readily yield a diagnosis but often does not. A system that lists problems based on the level of information available has a clear advantage over a system that tends to force a premature diagnosis. The problem-oriented medical record is an example of the former system. This method of recording data, which allows identification of discrete problems and their relationships to one another, is especially useful in sorting out complex situations. It also has the advantage of reducing the chances that some problems will be ignored in developing a coordinated 4 treatment plan. For example, a patient with an open bite may also be found to have increased lower facial height, retruded chin, lip incompetence, increased nasolabial angle, increased maxillary-alveolar bone height, increased backward rotation of the mandible, minor crowding of the dental arch, and increased curve of Spee in the maxilla. Without a listing of all of the problems, it is easy to focus only on the chief complaint of open bite or perhaps some, but not all, of the other problems. In this example, attention only to the open bite could result in a surgical procedure to close the bite by inferior movement of the anterior maxilla to permit occlusion of the maxillary incisors with the mandibular incisors. This approach to treatment, while providing a good occlusion, would fail to correct other problems and would even create a new one - changing a normal maxillary lip-to-tooth ration to one with excessive exposure of the teeth. On the other hand, recognition of the various problems and their relationships to each other would more likely lead to another treatment plan. A better plan would be developed if there was recognition that vertical increase in the maxillary bone rotates the mandible, creating a secondary deficiency of the chin, increasing lower facial height, and causing lip incompetence. Thus segmental maxillary osteotomy, with intrusion of the posterior segments and rearrangement of the anterior segments, would also close the open bite. In contrast to the anterior maxillary osteotomy alone for closure of the open bite, this plan would address the other coexisting problems. Thus the combination of a segmental maxillary osteotomy with intrusion to retain the present adequate lip-to-tooth relationship could correct the open bite as well as other important abnormalities. Specificially the procedure would correct the occlusion and provide some correction for the deficient chin, increased lower facial height, and lip incompetence by allowing the mandible to rotate forward. The need for an orthodontist to align the teeth also would be more obvious with this problem-oriented approach. Thus the competent surgeon not only exercises care and thoroughness in collecting data through the patient evaluation but also organizes these data in a way that encourages an analytical evaluation of problems and, thereby, a more rational approach to surgical therapy. The analytical approach is also applicable to other aspects of surgical care. Careful assessment of a patient's problems and meticulous planning for the surgical procedure usually eliminate any significant surprises during the operation. But occasional unanticipated findings or events are unavoidable. A few moments of analysis of the situation usually suggest the best course of action. A careful, thorough approach is more important than speed. Surgeons have an obligation to improve therapy by advancing surgical knowledge. If we do not advance surgical knowledge, our patients will pay the price for our failure to do so. Testing carefully posed hypotheses in the laboratory and evaluating the results of treatment are the two chief means of advancing surgical knowledge. While not all surgeons will have the opportunity or skills required for testing hypotheses in the laboratory, all of us do have the opportunity to learn from the care given our patients. When we evaluate or compare methods of therapy, it is important to make accurate observations. The history of surgery is replete with examples of new operations that, after their initial enthusiastic recetion, were found to be ineffective and were therefore discarded. This disservice to patients largely can be avoided by utilizing a study design that minimizes the chances for error in interpretation. Observer bias, placebo effect, individual variability, and comparison of treatment groups with inapppropriate controls are well known for their ability to obscure the real effects of therapy. Response of the Body to Injury Surgeons, unlike other practitioners, treat patients who have injuries. The injury may be caused by such diverse means as the surgeon's scalpel or a motor vehicle. Francis D Moore and others have elucidated the major features of the metabolic response of the body to an 5 operation. Knowledge of the characteristics of this response provides the surgeon with a means of assessing the patient's progress after an operation and provides cluses for therapy. The body's reposnse to a surgical procedure, in general, seems to be directed toward maintenance of the internal environment by a process termed homeostasis. That is, an operation activates autoregulatory mechanisms that enhance the ability of a person to withstand the injury. One insult causing this response is hemorrhage. Loss of about 15% of blood volume by venous hemorrhage causes characteristic changes. Typical early changes includes increased blood levels of epinephrine, norepinephrine, aldosterone, angiotension, renin, and antidiuretic hormone. These mechanisms promote conservation of body water and sodium and especially intravascular volume. The depression of urine and sodium excretion by hemorrhage is shown. These and other responses restore the intravascular water, electrolytes, and protein content. In fact, the transcapillary filling begins almost immediately after onset of hemorrhage, and volume restoration is complete 18 to 24 hours later. The response of the patient to an operation may be divided into four phases of convalescence. The first phase is acute injury, and it is characterized by a catabolic state. This phase lasts for 2 to 5 days, depending primarily on the magnitude of the surgical procedure, the quality of care after operation, and the health status of the patient. During this time the patient is apathetic and generally wishes to be left alone. The metabolic response includes negative nitrogen and potassium balances and increased catecholamine and corticosteroid production. Most of the studies concerning the response to injury have been concerned with this first phase. The catabolic phase ends rather abruptly with the "turning point". During this brief phase, the patient begins to expand his concerns from his own small world to the larger events of life. He becomes more active and alert, his appetite increases, and diuresis begins. The major metabolic alterations of the acute injury phase are reversed. The "turning point" phase then passes into an anabolic phase. In this phase the patient experiences a further gain in appetite, gains strength, increases activity, and has a return of sexual function. A positive nitrogen balance continues until the nitrogen losses are restored. The anabolic phase lasts for about 2 to 3 weeks, during which time lean muscle mass is restored. The last phase is characteried by a gain in fat. There are two chief ways to design surgical care based on these predictable responses to injury. One approach is to alter responses that seem to be at odds with attempts to help patients recover from injury. Excessive amounts of edema, for example, can be reduced by appropriate use of corticosteroids. But, there are other responses that are not modified to any appreciable extent by active treatment. The negative nitrogen balance that follows injury has resisted, with some success, numerous efforts to reverse it. A second and more common way to utilize knowledge of the response to injury is to design therapy to work in concert with these changes. Knowing that for about 2 days after an operation there is significant water and sodium retention is obviously useful in administering intravenous fluids properly during this period. Another factor concerns the severalfold rise in corticosteroid production after an injury. Blood levels become elevated almost immediately and persist for 2 to 3 days after an operation of mild to moderate severity. However, when the adrenal-pituitary axis has been suppressed by the long-term use of corticosteroids, the patient's adrenal gland is unable to respond to increased demands for several months after cessation of steroid therapy. Extraction of teeth in such a patient requires replacement therapy during this period of increased corticosteroid need to avoid the profound shock and death that otherwise can occur. A final factor concerns diet. During the acute injury phase, diet, in contrast to fluid balance, is relatively unimportant. The body shifts to a catabolic state for production of energy during this transient phase of starvation. With the later anabolic phase, however, diet assumes a key 6 role. A nutritious diet rich in protein and calories is needed for restoration of lean muscle mass. Management of wounds is a fundamental skill of the surgeon. Wounds, like the body, respond in a predictable manner. While the general status of a patient clearly has an influence on wound response, more often local factors are the major determinants. Nonetheless, a fairly serious derangement of a patient's health can affect the wound response perceptibly. Such factors as poor nutritional status can retard wound healing. In the scorbutic individual, for example, wounds heal poorly and have little tensile strength. For the majority of patients, the manner in which wounds are made and cared for largely determines how they heal. Even in patients in whom the wound is appreciably influenced by their general status, good operative technique and postoperative care permit optimal healing under the circumstances. Understanding how different wounds heal is important in planning wound management. An open, soft tissue wound, for example, displays remarkable contraction during healing. The epithelial edges move toward one another with marked diminution in size of a wound scar. This contracture phenomenon can virtually eliminate a sulcus created by a vestibuloplasty procedure that leaves an open wound. The contracture is especially great on the labial side of the mandible but can be inhibited by several methods. One of the most effective ways is to cover the raw surface with an epithelial graft, especially a full-thickness graft. In fact, truly effective vestibuloplasty techniques did not evolve until these methods guided development of the operative procedures. After the wound has been closed, the care administered until healing has progressed to a scar can greatly influence the course of events. The dressing of wounds and timing of removal of drains or sutures influence the rate of healing as well as the nature of the ultimate scar. For example, improper dressing care that allows a secondary wound infection delays healing and creates a more prominent scar. Immobilization of wounds, such by use of a stent or sutures for graft immobilization in vestibuloplasty procedures, is another instance in which the predictable response of a wound is utilized in planning for optimal care. Summary Surgical principles can be grouped into three major areas: asepsis, the analytical approach to surgical care, and the formulation of surgical care based on the response of the body to injury. The best surgeons not only base surgical therapy on these principles but leaven them with a generous portion of humane, compassionate concern for the patient. 1 Textbook of Oral and Maxillofacial Surgery Gustav O Kruger (The C V Mosby Company, St Louis, Toronto, London, 1979) Fifth Edition Chapter 2 Principles of surgical technique Theodore A Lesney Sterilization of Armamentarium Introduction The prevention of infection is surely the mandatory requirement of surgical practice and is thereby foundational in the establishment of sound surgical techniques. Infection control is certainly not limited to the sterilization of instruments, supplies, and accessories alone or to the establishment of good dressing-changing routines in the clinic or in professional office practice. Equally important is an awareness of the need for reduction of pathogens in the general environment, and, of course, the responsible surgeon is ever-alert to the need for preventing cross infection among circulating personnel, reducing microbes in room air, and eliminating human error and carelessness that tends to break down the chain of asepsis. Currently physical technology continues to remain preferable to chemical methods for the sterilization of armamentarium and supplies. Moist heat is still the most reliable and least expensive means for destroying undesirable microbes. There are other, less effective, physical methods than steam, such as filtration, irradiation, and ultrasonics, but these are generally employed where the application of saturated steam is not feasible. In the field of sterilization some hard facts important for the student of surgery to understand should be quickly established. For one thing, the rhetoric used must not be confusing or compromising. So, it is hereby agreed that sterilization shall mean the total destruction of microbial and viral life. Terms that are often related to sterilization, such as sanitation, antisepsis, and disinfection, must be clearly recognized as representing conditions less than sterile that thereby fail to meet the total requirements of sterility. As a basic principles of asepsis, there can be only one form of sterilization, the complete destruction of pathogens. Textbook rhetoric permits the use of some commonl accepted suffixes such as "cide" and "stat", to name only two. These suggest a varying effect on the life cycle of microbes. For instance, a bactericide destroys bacteria but a bacteriostat only inhibits its growth. Similarly, a virucide kills virus, a fungistat slows the growth of fungus, and so on. Spore- forming pathogens provide the ultimate test for efficacy of sterilization practices, and, in this 2 regard, saturated steam has proved to be the most practical, the most economical, and the most currently effective sporicide. Principles of sterilization The basic fundamentals of sterilization procedures will be briefly discussed to ensure that requirements of undergraduate education are fulfilled. The fact remains that today one rarely sees a boiling-water sterilizer or a dry-heat oven in operation on a ward or in the clinic. Presterilized, singe-use disposables have largely eliminated the need for this equipment. Also, gas sterilization such as with ethylene oxide is being used on a progressively limited basis. Nevertheless, these are tried and proved techniques that have prevailed over the years and will continue to remain reliable until supplanted by better methods in the progressive evolution of medical technology. Autoclaving. Autoclaving is the preferred method of sterilization and the most reasonably certain to destroy resistant spore-formers and fungus. It provides moist heat in the form of saturated steam under pressure. This combination of moisture and heat provides the bacteria-destroying power currently most effective against all forms of microorganisms. Instruments and materials for sterilizing in the autoclave are usually enclosed in muslin wrappers as surgical packs. Muslin for this purpose is purchased most economically in bolt lots and cut to desired size. It is used in double thickness, and each surgical pack is marked as to contents and date of sterilization. Paper is now apparently supplanting muslin for wrapping surgical packs. Several manufacturers are producing various types of paper wrappers. These papers have clothlike handling properties and present several advantages over muslin. They are less porous than muslin and thereby are less likely to be penetrated by dust and microorganisms. However, they are sufficiently porous to permit required steam penetration under pressure. Crepe papers are currently in favor; they have some degree of elasticity and can be reused several times. Sterility under adequate paper wrapping appears to be effective for periods of 2 to 4 weeks' shelf life. This compares favorably with muslin-wrapped surgical packs. Autoclaving time will vary directly with the size of the surgical pack. The smaller packs used for oral surgery usually require 30 minutes at 121°C under 1.40 kg 2 of pressure. Various sterilization indicators can be inserted into a pack to provide evidence that adequate steam penetration has been effected. Rubber gloves are more fragile than linens and most instruments. They are sterilized effectively after 15 minutes under 1.05 kg 2 of pressure at 121°C. Boiling-water sterilization. Ordinarily boiling-water sterilizers do not reach a temperature level above 100°C. Some of the heat-resistant bacterial spores may survive this temperature for prolonged periods of time. On the other hand, steam under 1.05 to 1.40 kg 2 of pressure will attain a temperature of 121°C, and most authorities concur that no living thing can survive 10 to 15 minutes' direct exposure to such saturated steam at that temperature. If boiling-water sterilization must be used, it is recommended that chemical means be employed to elevate the boiling point of water and thereby increase its bactericidal efficiency. A 2% solution of sodium carbonate will serve this purpose. Sixty milliliters of 3 sodium bicarbonate per gallon of distilled water will make a 2% solution. This alkalized distilled water reduces the required sterilization time and the oxygen content of the water as well, thereby reducing the corrosive action on the instruments. Dry-heat sterilization. Sterilization in dry-heat ovens at elevated temperatures for long periods of time is widely used in dentistry and oral surgery. This technique provides a means for sterilizing instruments, powders, oils (petrolatum), bone wax, and other items that do not lend themselves to sterilization by means of boiling water or steam under pressure. Dry heat will not attack glass and will not cause rusting. Furthermore, the ovens have additional uses in dentistry, such as baking out and curing plastic pontics and other applications. The general design of the ovens permits a heating range between 10° and 200°C. Overnight sterilization in excess of 6 hours at 121°C is widely employed. Adequate sterilization of small loads is attained at 170°C for 1 hour. Manufacturers of dry-heat sterilizers provide detailed instructions for their effective use. The major disadvantage of dry-heat sterilization obviously is the long periods of time required to ensure bactericidal results. Cold sterilization. None of the chemicals used for cold sterilization satisfactorily meets all of the requirements for true sterilization. Alcohol is expensive; it evaporates readily and also rusts instruments. The widely used benzalkonium chloride, 1:1.000 solution, requires an antirust additive (sodium nitrate) and long periods of immersion (18 hours). The more recently introduced cold-sterilizing chemicals employ hexachlorophene compounds as the active base. These chemicals claim adequate sterilization of heat-sensitive instruments in 3 hours. Fundamentally, most of the cold sterilizing media that may be safely used probably kill vegetative bacteria, but there is doubt of their effectiveness against spores and fungus. Gas sterilization. The limitations of chemical solution sterilization techniques have made it necessary to exploit other methods for sterilizing the heat-sensitive or water-sensitive armamentarium. One of these methods employs a gas, ethylene oxide, which has proved to be bactericidal when used in accordance with controlled environmental conditions of temperature and humidity as well as an adequate concentration of the gas for a prescribed period of sterilzing exposure. Ethylene oxide sterilizers are currently manufactured in varied sizes from the small portable table model (chamber measuring about 7.5 cm in diameter), to the large, built-in, stationary apparatus found in many hospitals. Smaller chambers use gas that is provided from convenient metal cartridges. The large, built-in sterilizers are hooked up to multiliter tanks. The relatively high cost of using ethylene oxide sterilizers frequently results in their being used only once or twice per day, more often for overnight sterilization of a capacity load. A hermetically sealed apparatus is necessary to economically ensure the retention of the expensive gas at its most effective concentration for a prolonged period of time ranging from 2 to 12 hours. Since ethylene oxide is highly diffusible, it requires a containing apparatus of precise manufacturing detail. Under arid conditions, desiccated microorganisms are known to resist the bactericidal effectiveness of ethylene oxide. Therefore the relative humidity within the sterilizing chamber should be controlled at an optimum of 40% to 50%. Also the efficiency of the gas sterilizer is reduced directly by temperature drops below 22°C. 4 In general, gas sterilization as currently employed in ethylene oxide techniques does indeed fill a necessary void in presently available sterilization practices, but its shortcomings dictate the urgen need for better and less expensive methods. Sterilization of supplies on industry-wide level Our expanding population and the successful practice of geriactrics have greatly increased the demand for more medical services. Although the construction of hospitals to meet this demand has been slow, and the training of medical personnel has been even slower, it is encouraging to observe the notable achievements of the pharmaceutical and hospital industry in the mass production of medical supplies. One major achievement concerns the development and profession-wide acceptance of sterile disposable (single use) items. There are now so many disposable products in daily use that space precludes their individual discussion. Another achievement involves automation in manufacture, processing, sterilization, and packaging on an industrial scale. It is the sterilization of disposables and other mass- produced medical supplies that shall be discussed. Modern manufacturing methods for medical supplies and their marketing have pointed out the shortcomings of former sterilization practices when applied to this industry. Although formerly heat, steam, gas, and bactericidal solutions were the only widely accepted means for sterilization, these methods could not be adapted to current mass production and marketing techniques. Many supplies, containers, illustrations, and enclosed printed matter could not withstand these sterilization procedures. The hermetic sealing of products and packages was impossible, since asepsis was dependent on permeation by heat, steam, gas, or batericidal solutions. Heat-sensitive and water-sensitive equipment and supplies required special handling that was inadaptable to mass-production practices. Recently a radical change has been instituted in sterilization procedures for manufactured and packaged medical supplies. The change has been expensive but effective. Its success in industry has focused the attention of the professions on some of the rather archaic sterilization techniques. Briefly, the improved sterilization techniques employ ionizing radiation. The pharmaceutical and hospital industries are credited with developing, at considerable expense, a successful radiation sterilization technology. The military establishment of the federal government has also played a major role with its studies of irradiation sterilization of foodstuffs for preservation purposes. Both groups have contributed knowledge and standardization of irradiation techniques to the degree that now permits the safe and efficient use of gamma rays and accelerated beta rays on the wide scale employed in food and drug technology. The manufacturer is now able to package the product in a variety of containers that could not be used with previous sterilization methods. Directions, legends, illustrations, and heat-sensitive and water-sensitive materials can be included and yet meet the professions' requirements of sterlization. As a matter of fact, in much of the industry the contents are packaged for final shipment before they are run through an irradiation building on a conveyor-belt system for the efficient sterilization of the entire shipping container and its contents. Radiation sources. Ionizing radiation for sterilization as currently practiced is available from two sources: (1) machines of low energy but high output (electron accelerators) and (2) radioisotopes. The machines convert the electron output in a manner somewhat [...]... covering is made of waterproof material or otherwise backed by a waterproof lining or sheathing Modifications of aseptic routine for office pracice of oral surgery One school of thought will insist that there can be no compromise with the aseptic measures employed in surgery Another group may insist that a rigid aseptic technique is not practical in a busy office practice dealing with minor oral surgery in... patient for oral surgery, the danger of cross infection is omnipresent All reasonably intelligent efforts at limiting this danger of infection are the least that the patient should expect from the doctor 10 Much of the operating room decorum employed for major surgery is within practical limits for oral surgical procedures In the hospital operating room the level of the surgical table is the line of demarcation... the immediately submandibularcervical zones The skin of the face and neck is generously endowed with wrinkles and creases representing lines of tension and relaxation of the skin in its response to the action of the muscles of expression and mastication The depth of the skin wrinkles varies with the age and weight of the patient and the placement of these creases is generally symmetrical Planning the... since oral epithelium regenerates so rapidly in an injured mouth, just a few hours of topical dressing may carry a patient through the most painful period and also provide protection for the continued healing of a granulating wound A more detailed discussion of intraoral dressings ranging from adhesive foils to waterproof cements is readily available in any current periodontal textbook Dressing extraoral... condylar head or along the inferior margin of the zygomatic arch No surgical danger is anticipated deep to the temporalis fascia and lateral to the condyle There may be some retraction paralysis of some of the branches of the facial nerve, since the area of exposure is small although adequate This will be a temporary paralysis If further surgery deep to the neck of the condyle is required, this must be... way of the external auditory meatus Armamentarium Some of the more frequently used instruments and supplies for oral surgery are illustrated and identified in the figure These are normally set up in sterile packs or case pans 23 for routine use in oral surgical problems To these routine setups the surgeon will add the special armamentarium required for a particular surgical problem 24 Textbook of Oral. .. about to invade is of course mandatory It is common practice among young surgeons of limited experience to perform the proposed surgery in cadaver dissection prior to the actual operation Such procedure is good technique and is not to be misinterpreted as indicating deficiency Submandibular approach to the ascending ramus and body of the mandible Most extraoral surgery requiring exposure of the mandible... made in one of the lines of skin tension, and it should be predetermined and marked either by superficial scratching with the back edge of a scalpel or by marking with an anyline dye The gonial angle of the mandible and the notch in the inferior border of the mandible (produced by the pulsating facial artery) should be marked as points of reference, the former indicating the posterior terminus of the operative... location of the facial artery and the facial vein The incision is placed in the shadow line of the mandible about 2 cm below the inferior border of the mandible and curved 18 in best cosmetic conformity with that bone This distance below the mandible will avoid the cutting of the mandibular branch of the facial nerve The total length of the incision may vary between 6 and 8 cm Crosshatching the line of incision... point Minor variations of the soft tissue surgery described will be required to meet the demands of surgery in more anterior aspects of the lower face If the body of the mandible is to be approached, the location of the incision is placed more anteriorly The amount of exposure required determines the length of the incision Usually 6 to 7 cm will be found adequate, but accessibility should not be sacrificed . covering is made of waterproof material or otherwise backed by a waterproof lining or sheathing. Modifications of aseptic routine for office pracice of oral surgery One school of thought will. rotation of the mandible, minor crowding of the dental arch, and increased curve of Spee in the maxilla. Without a listing of all of the problems, it is easy to focus only on the chief complaint of. concern for the patient. 1 Textbook of Oral and Maxillofacial Surgery Gustav O Kruger (The C V Mosby Company, St Louis, Toronto, London, 1979) Fifth Edition Chapter 2 Principles of surgical technique Theodore