Immobilization of fractures of the facial skeleton: past and present.

Immobilization of Fractures of the Facial Skeleton: Past and Present within 20 days when using this method of fixation provided no infection occurred.2 In AD 30 Celsus described a method for fixation of mandibular fractures similar to that described by Hippocrates, but he introduced horsehair as a ligature material. In India, horsehair had already been used for suturing skin wounds.1 Following fixation, Celsus forbade his patients to speak and told them to live exclusively on liquid food for several days. Although in ancient times mandibular fractures were fixed only at the fractured jaw itself or exterANCIENT TECHNIQUES: nally at the skull, Salicetto introduced intermaxillary EXTERNAL FIXATION fixation in 1474.3 Since the simple ligatures still used today in emerMandibular Fractures gency care were relatively instable, Bunon develThe first reports describing the treatment of man- oped a dental splint in 1743. He used an ivory block dibular and maxillary fractures that we know of to which he tied all lower teeth by means of threads.4 In 1779, Chopart and Desault described the use of come from Egypt and date back to the 17th century a simple dental splint in combination with external BC. They were found in the so-called Edwin Smith Papyrus, which was decoded by Breasted in 1930.1 fixation (Fig. 2).5 They actually used a type of screw The fractures were fixed by simple wooden splints clamp to which the fractured mandible, a chin plate, and a bite block were fixed. In 1823 Rutenick deand linen splints soaked with glue. In the fifth century BC, the father of medicine, scribed a similar device which, in addition, was Hippocrates, concerned himself with lesions of the cranially attached to a helmet by means of ribbons6 jaws. He not only invented the technique to reduce a (Fig. 3). Since the middle of the 19th century, the treatment dislocated mandibular head, which still carries his name (Fig. I), but also taught methods of immobiliz- of mandibular fractures has been characterized by ing a fractured mandible. The fracture ends were many modifications and refinements of immobilizareduced by hand and even in those times were fixed tion by means of dental splints. In 1855 Hamilton by means of threads tied around the teeth. In addi- introduced the gutta-percha splint prepared in the tion to this intraoral immobilization, he recommended patient's mouth following reduction of the fracture. extraoral fixation by means of strips of leather glued This splint enjoyed wide application, particularly to the skin, the ends of which were tied over the during the American Civil War.2 In 1858, Hayward skull. According to Hippocrates, the fracture healed developed a metal splint for severely dislocated fracModern osteosynthesis plates and screws are the result of manifold experience gained in the management of fractures of the middle third of the face, that is, their reduction and immobilization, since ancient times. It is the purpose of this article to report on some milestones in this long development leading to the use of plates for fixation of mandibular and midfacial fractures.

Department of Otorhinolaryngology, University Hospital, Liibeck, Germany Reprint requests: Dr. Siegert, Department of Otorhinolaryngology, University Hospital, Ratzeburger Allee 160, D-2400 Liibeck, Germany Copyright 01991 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.

Downloaded by: Universite Laval. Copyrighted material.

Ralf Siegert, M.D., D.M.D., and Hilko Weerda, M.D., D.M.D.

tures, such splint being adjusted to the individual needs on the basis of a plaster model of the jaws7 (Fig. 4). Rubber splints were first described by Weber in 18652 and since gained in importance, since rubber was stronger than gutta-percha and easier to process than metal. In 1866 Gunning introduced a new type of splint also made of caoutchoucs (Fig. 5). He fitted the splint to models of the upper and lower jaw after sawing up the mandibular model in the region of the fracture and reducing it. His splint was a block comprising upper and lower teeth and thus fixing the fractured mandible to the maxilla. A slightly modified form of the Gunning splint is still used today in the treatment of mandibular fractures in edentulous patients. In 1871Hammond developed a wire ligature splint for mandibular immobilization. In 1887 Gilmer reintroduced intermaxillary fixation, a technique that had been forgotten for centuries, and in 1897 Heitmiiller introduced intermaxillary elastics to reduce and immobilize fractures of the jaws.2 During World War I, many modifications of dental . splints were developed, then in 1956 Schuchardt Figure 1. Reduction of a dislocated jaw according to described his acrylic-coated dental arch bar, which is Hippokrates (reported in a manuscript of the 9th century). commonly used today9 It may be fitted directly in (From Bereny.2 Reprinted with permission.) the patient's mouth or preshaped in a model. Its stability is achieved by the combination of wire ligatures with a cold-curing resin. Temporary use of hooks bent onto the occlusal surfaces of the teeth prevent cervical dislocation of the splint and thus damage to the gingiva (Fig. 6).

Midfacial and Zygomatic Fractures

Midfacial fractures are rare compared with fractures of the lower jaw and therefore little scientific attention was paid to them in the old times. Although a description of a maxillary fracture was found in the Edwin Smith Papyrus, it was only in 1823 that von Graefe described the first apparatus to immobilize a fracture of the upper jaw (Fig. 7). Metal bars were fixed to the premolars and then tied to a headband.3 In 1866 Guerin described the horizontal maxillary fracture at the level of the piriform aperture that is still carries his name.10 This was the first attempt to establish exact details on typical fracture lines in the maxilla. The classification published by Le Fort in 1901 as a result of his experimental and pathologic studies was more comprehensive, covering the three typical fracture lines in the maxilla, and has gained general acceptance since then11 (Fig. 8). Reduction of depressed zygomatic fractures by Figure 2. Apparatus to immobilize a fractured mandible means of a one-prong hook dates back to the techaccording to Chopart and Desault (1779). (From Bereny.2 nique described by Strohmeyer as early as 1844.2 In Reprinted with permission.) 138


FACIAL PLASTIC SURGERY Volume 7, Number 3 1990

FRACTURE IMMOBILIZATION-Siegert,

Weerda

H

H

Figure 4. The splint according to Hayward (1858). (From Dingman and Natvig.3 Reprinted with permission.)

the beginning, however, no fixation of the reduced zygomatic bone was applied. Only since the turn of the century, a number of techniques have been described by which it is possible to keep the zygomatic bone as well as the depressed midface in their proper position following reduction. For all these techniques a wire or hook extension was used suspended from either a head cast12 (Figs. 9, lo), an extensive cast covering head and shoulders13 (Fig. ll),or the bedstead14 (Fig. 12).

OLD TECHNIQUES: THE DEVELOPMENT OF OSTEOSYNTHESIS Wire Sutures

Figure 5.

The Gunning splint (1866).

Since, with external fixation, considerable problems were involved for the patient, fracture reduction


Figure 3. Immobilization of fractured mandibles according to Rutenick (1799). (From Dingman and Natvig.3 Reprinted with permission.)

Figure 6.



Acrylic coated dental arch bar.

Figure 7. Apparatus for fixation of midfacial fractures according to von Graefe (1823). (From Dingman and Natvig.3 Reprinted with permission.)

was not guaranteed and immobilizationwas unstable, Rodgers dared to perform the first open reduction, in 1826. He applied wire sutures for an osteosynthesis in the case of pseudarthrosis of the humerus.15 Baudens is said to have been the pioneer in wiring mandibular fractures.16 In 1840, he used circumferential wiring to immobilize an oblique fracture. In 1847, Buck applied wire sutures directly to the fractured bone to stabilize the fracture.17 Mod-

Figure 8. Classification of midfacial-fractures according to Le Fort (1901). A: Le Fort I fracture. (Figure continued on next page)

Figure 8, cont.

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B: Le Fort II fracture. C : Le Fort Ill fracture.

Figure 9. Extension suspending from a head cast for fixation of a depressed zygoma. A: clinical aspect. B: radiogram.



Figure 10. A, 6: Wire extension suspended from a head cast for fixation of a depressed midface. (From Schroll.12 Reprinted with permission.)

ifications of this technique to increase stability further and prevent vertical dislocation were the two double wires (Rosel8) and the figure-of-eight wire suture (Raaslg).Adam90 in 1942introduced the technique of internal craniofacial suspension of the midface as well as direct wiring of zygomatic fractures at the zygomaticofrontal sutures (Fig. 13). His technique largely displaced external wire suspension of the midface in the followingyears and has since been one of the most important technqiues for immobilization of midfacial fractures. Although several modifications of wire fixation have been published,21,22 the original technique as described by Adams is still being applied in many cases today.

nector" developed by Morris in 1949.27 Following reduction, screws were placed transcutaneously into the fractured mandible and externally connected by means of a cold-curing resin. A similar procedure was published by Becker in 195828 (Fig. 15). A particularly interesting version of pin fixation is the permaxillary screw extension for depressed zygomatic fractures, according to Heidsieck.29 A continuously threaded screw is placed transcutaneously into the zygomatic bone until the floor of the maxillary sinus is reached. Further tightening of the screw slowly raises the depressed zygomatic bone because of the resistance produced by the floor of the maxillary sinus. Thus, it is possible cautiously to reduce the zygoma (Fig. 16).

Pin Fixation Immobilization by Plates and Screws Although the first percutaneous nailing of fracThe first osteosynthesis plate was used by Lane30 tured long bones was done by Parkhill as early as 1897,23 the use of Kirschner wires to treat mandibu- almost 100 years ago. Apparently his idea was too lar fractures was published only in 193224 (Fig. 14). advanced for his times, for it did not succeed and fell Following restoration of normal occlusion, the frac- into oblivion. It was not until 1943 that Bigelow detured fragments were transcutaneously fixed with a scribed screws and bars made of Vitallium-an alloy pin. Allegedly, intermaxillary fixation was not re- of cobalt, chrome, and molybdenum-for use in the management of mandibular fractures.31 quired.25126 In the following two decades a large number of Another step forward toward the present techniques of osteosynthesis was the "biphasic con- modifications of plates were described,3235 which



\ r

k 2 m

Figurell. Cast covering head and shoulder for reduction and fixation of a midfacial fracture. (From Pelser.13 Reprinted with permission.)

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Figure 12. Wire traction device for external fixation of a depressed midfacial fracture. (from Schroder.14 Reprinted with permission.)

for fixation

1

A Figure 13. A-D: Internal wire fixation of several midfacial fractures. (FromAdams.20 Reprinted with permission.)(Figure continued on next page)





Figure 13, cont.

144


FRACTURE IMMOBILIZATION-Siegert, Weerda

Figure 14. A, 6 : Application of Kirschner wires in a fractured ma.ndible. F:ram Ipsen.26

little by little announced the new age of osteosynthesis in the therapy of facial injuries. Their common characteristics were the principle of simple fixation-in contrast to the principle of compression developed later on-and the thickness of the plates, which restricted their application to mandibular fractures only. In order to stabilize the fractured bone better and accelerate bone healing, it is necessary to exert pressure when fixing the fracture ends. A forerunner of modern compression osteosynthesis was described by Key for knee-joint arthrodesis in 1932.36Heplaced two nails horizontally through the fragments and externally pulled them together by means of clamps. The principle of the gliding hole was introduced by Danis in 194937: the osteosynthesis plate has an oval

hole in which a not yet fully tightened bone screw can be moved axially. By an additional compression screw acting vertically on the screw placed in the gliding hole, the fracture ends are put under pressure and subsequently fixed in their position by tightening the first screw in the gliding hole. A totally different idea was pursued by Maatz.38 He produced compression by means of a spring bolt in the sense of a dynamic lag screw (Fig. 17A). On the basis of this principle, he later developed "medullary-space springs1' for the treatment of fractures of long bones and finally a ligature spring for dynamic circumferential bone wiring in the case of oblique fractures (Fig. 17B). Still another method of producing compression in oblique fractures was developed by Proske using



Figure 15. Fixation of a simple (left) and a double (right) mandibular fracture by screws and acrylics. (From Becker.28 Reprinted with permission.)

Figure 16. Screw extension for depressed zygomatic fractures. A: clinical aspect. B: radiogram. (From Heidsieck.29 Reprinted with permission.)

circumferential wiring put under pressure by means of an external traction mechanism39 (Fig. 18).Forgon combined the spring and the nailing principle40 (Fig. 19). The oblique fracture is first nailed and then compressed by means of springs. None of these technically interesting spring constructionswas generally adopted. Obviously, they were not stable enough and could be used in individual cases only. The main development in osteosynthesis techniques

therefore followed the principle of compression plates developed by Danis as early as 1949.37 In 1958, Bagby and Janes were the first to describe the compression hole, an oval hole in which the screw, while being tightened, is sliding on the oblique surface of the bottom of the screw head toward the fracture, thereby exerting pressure on the fracture41 (Fig. 20). However, the shapes of the bottom of the screw head and of the compression hole were not yet


Figure 17. Compression by means of a spring. A: Spring screw. B: Ligature spring. (From Maatz.38 Reprinted with permission.)

congruent and those early plates were not commer- holes that were congruent in shape and initiated cially available. These minor details are likely to have their large-scale production, was the way paved for been responsible for the fact that those early com- osteosynthesis being generally accepted also in the treatment of facial fractures. The first plates were still pression plates did not gain general acceptance. Only in the late 1960s when Luh+ (Fig. 21) and very "bulky," exclusively designed for use in mandiPerren et a143 (Fig. 22) developed plates with cone- bular fractures. Today, many different systems are shaped or spherical screw heads and compression available, ranging from the heavy compression plates

Figure 18. Tight circumferential wire constantly under tension (From Proske.39 Reprinted with permission.)

Figure 19. Compression wire osteosynthesis: Fracture put under compression by spring activated sleeves. (From Forgon.40 Reprinted with permission.)


A

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'FACIAL PLASTIC SURGERY Volume 7, Number 3 1990 Prox~rnol I

Drawing of compression platewith conical screw head. (From Bagby and Janes.41 Reprinted with permission.)


Figure20.

Distal 1

B

Figure 21. Drawing (A) and example (B) of compression plate with conical screw head. (From Luhr.42 Reprinted with permission.)


Y

A

B

E

D

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E

Figure 22. Compression plate with spherical screw head. (From Perren et a1.43 Reprinted with permission.)

Neither the principle of simple fixation osteosynthesis nor that of compression osteosynthesis has changed, except for the additional development of oblique compression holes enabling compression also at the cranial end of the fracture line despite caudal placement of the plate" (Fig. 23).


for mandibular reconstruction to the fragile plates for midface fixation. Many minor technical details have been improved over the past 20 years, for example, there are now plates with cross-slotted screws or socket head cap screws, holding devices for the screwdriver for one-hand management.

Figure 23. Osteosynthesis plate. The oblique compression holes produce an additional pressure in the alveolar ridge away from the plate. A: Drawing. (From Niederdellmann et a1.44 Reprinted with permission.) B: Alveolar gap using a compression plate at the caudal border of the mandible without oblique compression holes. C: Compression plate with additional oblique compression holes.

FACIAL PLASTIC SURGERY Volume 7, Number 3

Some of Today's Osteosynthesis Systems Thickness (mm)

Screw Type*

Screw Thickness (mm)

Com~anv

Name of System

Made in

Material

Clinician

Year

Plate Type*

Howmedica Leibinger Medicon

Luhr Micro System Micro System M i kro-Platten, Modell Minden Flachprofil Luhr Mini System Steinhauser Mandibula Set Craniofaciales Set Mini-Platten, Modell Minden Wurzburg Schadel + Gesicht HRS-Miniplatten Miniplatten

Germany Germany Germany

Vitallium Titanium Titanium

Luhr H G PosnickJC Heinl T

1989 1990 1989

f f f

0.5 0.55 0.6

s s s

0.111 .O 1.011.2 1.511.9

Germany Germany Germany Germany USA Germany

Titanium Vitallium Titanium Titanium Titanium Titanium

Luhr H G Steinhauser E A0 A0 Heinl T

1987 1978 1990 1976 1988 1987

fc fc f c fc

f

0.611 .O 0.7 0.7511.0 0.8 0.85 1.O

s s sn sn s s

1.512.0 2.012.4 2.012.3 2.713.2 1.512.4 2.012.3

Germany

Titanium

Reuther J

1986

f

1.O

s

2.012.3

USA Switzerland

Titanium Steel

1972 1978

f cf

1.O 1.O

s sn

2.012.7 2.0

Luhr Mandibular Compression System Kiefer Autokompressionsplatten Wurzburg Unterkiefer Salzburg

Germany

Vitallium

Messer EJ Becker R, Machtens E Luhr H G

1985

c

1.25

sn

2.713.0

Switzerland

Steel

Machtens E

1972

c

1.5

sn

3.5

Germany Germany

Titanium Titanium

Reuther I Krenkel C

1987 1988

cf

3.0

-

n n

2.713.2 2.0

Leibinger Howmedica Leibinger Synthes . Synthes Medicon Leibinger Hall Osteo Howmedica Osteo Leibinger Leibinger

-

*c: compression; f: fixation; s: self-tapping screws; n: not self-tapping screws.

TODAY'S TECHNIQUES: DIFFERENT SYSTEMS OF OSTEOSYNTHESIS FOR THE MANAGEMENT OF FACIAL FRACTURES Some of the most common plates for the management of facial fractures are listed in Table 1according to plate thickness, without claiming completeness. The plate thickness ranging from 0.5 to 3.0 mm decisively determines where and how a particular plate is used. The material the plate is made of also is of decisive importance. Today osteosynthesis plates are made either of stainless steel, titanium, a titanium alloy, or Vitallium. Steel has a comparatively poor biocompatibility and the manufacturers of those osteosynthesis plates have changed to other materials or plan to do so in the near future. Comprehensive experimental data and clinical long-term results have been gathered for titanium and Vitallium plates. Both materials are considered extremely biocompatible. Their mechanical properties differ only in that with equal mechanical stability Vitallium plates may be thinner. Most manufacturers offer so many different lengths and shapes of plates and screws for the various systems and possible uses that hardly any problems are encountered in the daily clinical routine. In order to guarantee equal loading of the plate and harmonious contouring, the long side of the plates should not be straight but follow the shape of the holes so that, at each point of the plate, the width of the metal is the same. Unfortunately, this requirement is not yet met by all systems. The use of compression plates makes sense in

comparatively thick bone only. They are mainly applied for osteosynthesis of the mandible or zygoma. However, a compression plate may also be used as a fixation plate, if the plate is placed in such a manner that the holes are drilled into bone close to the fracture line. In the beginning many osteosynthesis systems required tapping of the threads by means of a particular instrument, following drilling of the holes. Experimental studies by Bahr4-7 as well as Phillips and Rahn,4s however, revealed that self-tapping screws provide a higher stability, at least in thin midfacial bone, so that nowadays almost all manufacturers offer self-tapping screws, either exclusively or additionally. On the whole, the technology for the majority of the osteosynthesis plates is so advanced and sophisticated that hardly any technical problems should occur with correct management. Present clinical uses of osteosynthesis plates in the different regions of the face are described in the following articles.

REFERENCES 1. Breasted JH: Edwin Smith Surgical Papyrus. Facsimile and hieroglyphie transliteration w i t h translation and commentary Chicago: University of Chicago Press, 1930. Quoted from Thoma KH: A historical review of methods advocated for the treatment of jaw fractures, w i t h ten commandments for modern fracture treatment. A m J Orthod Oral Surg 30: 399-504, 1944 2. BerCny B: Aus der Geschichte der Behandlung der Gesichtsschadelfrakturen. In Reichenbach (ed): Traumatologie im Kiefer-Ges.-Ber. Miinchen, 1969


Table 1.

1990

Dingman RO, Natvig P: Surgery of Facial Fractures. Philadelphia: W.B. Saunders, 1964 Bunon: Essay sur les maladies des dentes. Paris, 1743. Quoted from Berkny, 1969 Chopart, Desault: Traite des maladies chirurgicales et des operations, qui leur conviennent. Paris, 1779. Quoted from Bereny, 1969 Rutenick: Dis. de fractura mandibulae. Berol. 1823. Quoted from Dingman, 1964 Kingsley NW: A treatise on oral deformities. Appleton, 1880 Gunning TB: The treatment of fracture of the lower jaw by interdental splints. NY Med J 3:433, 1866 Schuchardt K: Ein Vorschlag zur Verbesserung der Drahtschienenverbande. Dtsch Zahn Mund Kieferheilkunde 24: 39, 1956 Guerin A: Arch Gen Med 6 (VIII): 1, 1866. Cited in Le Fort, 1901 Le Fort R: Etude experimentale sur les fractures de la machoire superieure. Rev Chir Orthop 23:208-227, 1901 Schroll K: Reposition und Fixation von Oberkieferfrakturen durch intra-extraorale Verbande. Fortschr Kiefer Gesichtschir 11:165-168, 1966 Pelser M: Die dorsale Kopf-Schulter-Gipsschale als Hilfsmittel zur Reposition und Fixation von Frakturen des Gesichtsschadels. Fortschr Kiefer Gesichtschir 11:161-164, 1966 Schroder F: Apparate zur Reposition und Fixation der Kiefer-frakturen. Fortschr Kiefer Gesichtschir 11:116-123, 1966 Gerson GH, Julius NH: Dr. J. Kearny Rodger's Heilung eines nicht vereinigten Oberarmbruches. Magazin der auslandischen Literatur 17:374, 1829 Baudens M: Bulletin de l'academie royale de medicine 5:230 + 341, 1840. Quoted from Fuchs R: Ursprung, Indikation und Technik der Knochendrahtnaht in der Kieferbruchbehandlung. Medical Dissertation, Frankfurt, 1962 Buck G: N Y J Med: 211, 1847. Quoted from Fuchs R: Ursprung, Indikation und Technik der Knochendrahtnaht in der Kieferbruchbehandlung. Medical Dissertation, Frankfurt, 1962 Rose C: iiber Kieferbriiche und Kieferverbande. Jena, Fischer Verlag, 1893 Raas 0: Kiinstlicher Ersatz nach Kieferresektionen und Schienen bei Unterkieferbriichen. Dtsch Zahnarztl Z 7:3, 1908 Adams WM: Internal wiring fixation of facial fractures. Surg Gynecol Obstet 12:523-540, 1942 Macintosh RB, Obwegeser HL: Internal wiring fixation. Oral Surg 23:703-708, 1967 Kufner J: A method of cranio-facial suspension. J Oral Surg 28:261-262, 1970 Parkhill C: New apparatus for fixation of bones after resection and in fractures with tendency to displacement. Trans Am Surg Assoc 15:251-256, 1897 Bjerrums 0 : Om Underkaebebrud. Kopenhagen, 1932. Quoted from Ipsen 1933 Fries R: Markdrahtung bei Unterkieferfrakturen. Fortschr Kiefer Gesichtschir 11:225-228, 1966 Ipsen J: Eine Behandlung von Kieferbruchen. Zentralbl Chir 60:2840, 1933

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Morris JH: Biphase connector, external skeletal splint for reduction and fixation of mandibular fractures. Oral Surg 2: 1382-1398, 1949 Becker E: Ein Instrumentarium zur extrakutanen Osteosynthese bei Unterkieferfrakturen unter Verwendung plastischer Kunststoffe. Chirurg 29:63, 1958 Heidsieck C: Permaxillare Schraubenextension bei Jochbeinfrakturen. Dtsch Zahnarztl Z 20:316, 1965 Lane WA: A method of treating simple oblique fractures of the tibia and fibula more efficient than those in common use. Trans Clin Soc: 27, 1893. Quoted from Lane WA: Some remarks on the treatment of fractures. Br Med J 1:861, 1895 Bigelow HM: Vitallium bone screws and appliances for treatment of fracture of mandible. J Oral Surg 1:131, 1943 Beal G, Levignac J: Osteosynthkse mandibulaire. Rev Stomat01 (Paris) 56:424, 1955 Palfer-Sollier M: L'osteosynthese par gouttieres oissees en Durallium dans les fractures mandibulaires. Rev Fr Odontostomat 3:587, 1956 Hoffer 0 , Arlotta P: Behandlung von Unterkieferbruchen mit Metallplattchen. Dtsch Zahnarztl Z 16:807, 1961 Robinson M, Yoon CH: The "L" splint for the fractured mandible: A new principle of plating. J Oral Surg 21:395, 1963 Key JA: Positive pressure in arthrodesis for tuberculosis of the knee joint. South Med J 25:909, 1932 . Masson, Danis R: TEorie et practique de l ' o s t ~ o s y n t ~ s eParis: 1949. Quoted from Luhr HG: Die Kompressionsosteosyntkse bei Unterkiefwfrakturen. Miinchen: Carl Hanser Verlag, 1972 Maatz R: Osteosynthese mit Feder. Langenbecks Arch Klin Chir 263:201, 1949 Proske G: Kompressionsbehandlung von Schragbriichen durch Spanndrahtumschlingung. Chirurg 26:368, 1955 Forgon M: Uber percutane Hulsendruckosteosynthese. Chirurg 28:67, 1957 Bagby GW, Janes M: The effect of compression on the rate of fracture healing using a special plate. Am J Surg 98:761-771, 1958 -. ..

Luhr HG: Zur stabilen Osteosynthese bei Unterkieferfrakturen. Dtsch Zahnarztl Z 23:754, 1968 Perren SM, Runnenberger M, Steinemann S, Mueller ME, Allgower M: A dynamic compression plate. Acta Orthopaedica Scand Suppl 125:29, 1969 Niederdellmann H, Schilli W, Ewers R, Akuamoa-Boateng E: Photoelastic behavior of osteosynthesis plates with different arrangement of screw holes for mandibular fractures. Int J Oral Surg 4:27-31, 1975 Bahr W: Morphologiedes Knochengewindes nach Implantation von 2 mm AO-Minischrauben im Mittelgesicht. Unfallchirurgie 92:54-58, 1989 Bahr W: The effects of pre-tapping on the miniscrew-bone interface in the midface. J Craniomaxillofac Surg 17:337339, 1989 Bahr W: Pretapped and self-tapping screws in the human midface. Torque measurements and bone screw interface. Int J Oral Maxillofac Surg 19:51-53, 1990 Phillips JH, Rahn BA: Comparison of compression and torque measurements of self-tapping and pretapped screws. Plast Reconstr Surg 83:447-456, 1989



Cosmetic extensile exposure of the facial skeleton.

The craniofacial skeleton in anencephalic human fetuses. III. Facial skeleton.

The pannexins: past and present.

Colostomy: past and present.

Anatomy past and present.

Otosclerosis-past and present.

[Journals: past and present].

Anatomy past and present.

Pidotimod: the past and the present.

Oligonucleotide Therapies: The Past and the Present.

Polypharmacy: The past, present and the future.

Associations in the hominoid facial skeleton.

Facial fractures of the upper craniofacial skeleton predict mortality and occult intracranial injury after blunt trauma: an analysis.

Marchantia: Past, Present and Future.

Death: past, present, and future.

Integrons: past, present, and future.

Landfilling, past, present and future.

Macrophages: past, present and future.

Direct Influence: Past and Present.

Ribavirin: Past, present and future.

Psychosomatics: past, present and future.

Tonography: past, present, and future.

ALPPS: past, present and future.

Heparin: Past, Present, and Future.