Treatment of zygomatic fractures: Internal wiring-antral-packing-reposition without fixation

J. max.-fac. Surg. 4 (1976) 107-115 © Georg Thieme Verlag, Stuttgart

Treatment of Zygomatic Fractures: Internal Wiring-AntraiPacking-Reposition without Fixation A Comparative Follow-up Study Mikko Altonen, Aarno Kohonen, Kai Dickhoff

Department of Oral Surgery (Acting Head: M. Altonen, M.D.), Institute of Dentistry, University of Helsinki Departments o[ Otorhinolaryngology (Head: Pro[. T. Palva, M.D.), and Ophthalmology (Head: Prof. S. Va.nnas,M.D.) of Helsinki University Central Hospital, Finland

Summary Fifty-two patients with zygmnatic fractures were examined clinically and roentgenologically 1 to 4 years after treatment. Of these patients, 15 were treated with wiring fixation, 26 with antral packing using plastic tubing, and 11 with reduction only, without fixation. In the last group, the hospital stay was the shortest. These patients had also less complications and roentgenological changes when compared with the other groups. This was considered to be due to the fact that fractures not requiring fixation are initially less difficult than fractures requiring other treatment. At clinical examination, internal wiring fixation proved to be better than antral packing when hospital stay, restoration of the function of the infra-orbital nerve, the position of the eye, symmetry of the palpebral fissure and the final cosmetic result are considered. In the antral packing group, the result was better when jaw movements and occurrence of permanent diplopia were compared. The roentgenological examination revealed that the reduction results were more exact with internal fixation than with antral packing.

Key-Words: Facial fractures; Fractures of zygoma; Orbital fractures.

Introduction Many investigations have shown that trauma of the middle third of the face has been increasing since World W a r II. Injuries caused by both road traffic accidents and violence have increased simultaneously (Schuchardt et al. 1966, Miiller 1969, Oiharinen and MalmstrSm 1969, HStte 1970, Morgan et al. 1972, Tafima et al. 1974, Dickhoff 1975). Likewise, the treatment of facial trauma has become more important. Of the bones of the middle third of the face zygomatic bone was fractured in 6t to 81°/0 of cases (Dawson and Fordyee 1953, McCoy et 1962, Morgan et aI. 1972). Lateral fractures of

the the al. the

middle third of the face have been classified in different ways (Rowe and Killey 1955, Pape 1969). The grouping of zygomatic fractures, which are part of lateral fractures, was suggested by Knight and North (1961). The classification of orbital fractures has proved to be difficult (Pfeiffer 1962). The purpose of these classifications is to facilitate identification of each type of fracture and the choice of a suitable treatment. The results obtained by different treatment methods have been surveyed in otological and ophthalmological literature as well as in literature plastic and maxillofacial surgery. Often, these results have been viewed from only one aspect, i.e., indication for surgery, improvement of diplopia, and often a follow-up study has been made on one surgical method only. The majority of the patients in Carlson's and Mdrtensson's (1969) series had been treated with the Caldwell-Luc operation and tamponing of the maxillary sinus, while Gillies' method had been used in Lund's (1971) series. Hakelius and Pont~n (1973) compared the effect of open reduction, fixation and bone grafting, considering immediate and delayed presentation, on the improvement of diplopia. Tajima et al. (1974) investigated the postoperative results of open reduction in regard to delayed presentation. They also viewed tile results in relation to diplopia and enophthalmos. In ophthalmological studies, attention has been paid to the clinical picture of fresh orbital trauma and to results important from the ophthalmological point of view (Pfeiffer 1943, Schjelderup 1950 a, b, Converse and Smith 1950, 1957 a, b, and Greenwald et al. 1974). Notwithstanding, followup studies clarifying the ophthalmological aspect

108

M. Altonen, A. Kohonen, K. Dickhoff

Table 1 Age and sex distribution of fractures of the zygomatic bone. Age (in years)

Number of patients C~ ~

Total Number

10-19 20-29 30-39 40-49 50-59 60-69

5 12 6 10 5 1

0 3 3 2 2 3

5(10% ) 15 (29%) 9 (17%) 12 (23%) 7 (13%) 4 (80/o)

Total

39

13

52 (100°/o)

Table 2 Cause of injury in different treatment groups. Cause

Internal Antral NonTotal wiring pa&ing fixation

Traffic accident Violence Fall Occupational accident Sport injury Total

9 2 3

5 9 8

1 5 1

15 (290/0) 16 (31°/o) 12 (230/0)

1 0

3 1

2 2

6 (11°/o) 3 (60/0)

15

26

11

52 (100°/o)

Table 3 Distribution of 52 zygomatic fractures according to treatment method and Knight and North's grouping. Knight and North's group

Internal wiring

Antral Nonp a & i n g fixation

Total

I

0

2

0

2

II III IV V VI

0 3 3 6 3

0 8 10 4 2

3 2 1 4 1

3 13 !4 14 6

15

26

11

52

Total

of zygomatic fractures are few (H6tte 1970, Dickhoff 1975). The purpose of the present study was to clarify and compare the results obtained by the methods mentioned and by the treatment procedures used mostly in Finland as primary methods for frac-

tures of the zygoma. Simultaneously, efforts were made to clarify whether, in addition to major symptoms, limitations of mandibular movement, sensibility disorders of the infraorbital nerve and disturbed visual functions, other abnormal findings can be demonstrated and the relation of these to the treatment procedure used. Material and Methods

The patients treated for zygomatic fractures in 1966-1970 at the Departments of Otorhinolaryngology and Maxillo-Facial Surgery, Helsinki University Central Hospital, were selected as subjects for the present study. These patients were residents of Helsinki City or the surrounding rural areas. Fifty-five (800/0) of the 69 invited presented themselves for the examination. Three of these were excluded: one had had only a blow-out fracture, one had been treated with both internal wiring fixation and antral pa&ing, and one had had a complicated facial fracture which was not comparable with the other cases. The selection was performed in two different departments: one department, at the time in question, had patients with zygomatic fractures requiring" fixation who had been primarily treated with tamponing with plastic tubing through the transantral route (Kiviranta 196@ while in the other department, in corresponding cases, internal wiring fixation had primarily been employed. In both departments, some of the patients had been treated with reduction only, without fixation. It is seen from Table 1 that 750/0 of the subjects were males and 250/0 females. The sex and age distribution and aetiological factors correlate well with those in numerous publications (Carlson and Mdrtensson 1969, Lund 1971, Hakelius and Pontin 1973, Greenwald et al. 1974, Dickhoff 1975). Etiologically, violence and traffic accidents were most common, followed by falls, occupational accidents and sport injuries (Table 2). In the group of internal wiring fixations (15 cases), the majority of cases were traffic injuries. In the group of antral pa&ing (26 cases), violence and falls constituted nearly two-thirds of the cases, and in the nonfixation group (11 cases), violence was the aetiological factor in half of the cases. In 620/0 the fracture was on the left side and in 38O/o on the right.

Treatment of Zygomatic Fractures In order to obtain a picture of the quality of the fractures in the different treatment groups, the fractures were classified by treatment groups on the basis of primary roentgenographs and information obtained from patients' medical records, in accordance with Knight and North's (1961) grouping: Group Group

I No significant displacement II Zygomatic arch fractures

Group I I I Unrotated body fractures Group IV Medially rotated body fractures a) Outward at zygomatic prominence b) Inward at zygomatico-frontal suture V Laterally rotated body fractures a) U p w a r d at infraorbital margin b) Outward at zygomatico-frontal suture Group VI Complex fractures.

109 Table4 Distribution of associated head injuries in different treatment groups. Associated injury Le Fort I Lc Fort II Le Fort III Mandibular fracture Nasal fracture Concussion Contusion Total

Internal wiring

Antral pa&ing

Nonfixation

4 4 3

-

-

7 2 7 3

6 5 -

2 2 -

30/15

11/26

4/11

Group

In the internal wiring group, the fractures belonged to groups I I I - V I with emphasis being on group V. In the antral pa&ing group, the fractures fell more evenly into the different groups, with emphasis on groups IV and III. In the nonfixation group, the majority of the fractures were in groups V and II. Not all of the fractures were pure zygomatic ones. Especially in the internal wiring group they were often associated with facial fractures or brain injuries. The associated injuries are presented in Table 4. At follow-up examination, the subjects were examined clinically and roentgenologically. The pain, sinusitis, bite, visual disturbances and other possible subjective discomforts following treatment were clarified beyond doubt. At clinical examination, the lateral movements of the mandible and the maximum opening of the mouth in the incisor region were measured. The function of the orbital nerve was compared with the sound side by investigating its sensibility with a sharp and blunt object as well as a cotton swab. Possible fistulae and scars as well as facial asymmetries and other cosmetic defects were recorded, and when necessary, the patients were photographed from front and sides. At ophthalmological examination, the orbital region was palpated and the position of the eye-

Table 5 Hospital stay (in days) in differ.cnt treatment groups. Internal Antral NonAverage wiring packing fixation Without associated injuries 9.3 Associated injuries 27.3

12.6 16.1

4.8 9.0

9.9 20.4

Average

14.0

6.1

14.8

25.0

lids as well as the shape and size of the orbital rim were examined. Position of the globe in the antero-posterior direction was measured using the Hertell exophthalmometer. Visual acuity was measured with and without glasses, in decimals. The eyes were examined for possible intrabulbar changes. Ocular motility was examined and the occurrence of diplopia was investigated using the Armstrong red-green goggles. Lee's screen examination of the extra-orbital muscles was also carried out. At roentgenological examination, the conventional projections of facial fractures: posteroanterior, lateral, occipito-mental and axial, were taken using the Lysholm skull board. These radio-graphs were interpreted by a radiologist specializing in the investigation of the face and skull. He was requested to perform a follow-up examination of zygomatic fractures and to record as accurately as possible changes deviating from normal. He was not given any other information regarding, for example, the quality of fracture, the fractured side or treatment method.

110

M. Altonen, A. Kohonen, K. Dickhoff

Table 6 Results of clinical follow-up examination in diffcrent treatment groups. Treatment method

Opening of Lateral movemouth ~40 mm ment difference ~ 2 mm

Internal wiring Antralpacking Non-fixation Total

Sensibility of infraorbital nerve hyper

hypo

absent

Zygoma noticeably depressed

6(40% ) 7(27°/0) 1(19% )

9(60% ) 11(42% ) 3(27% )

1 (7%) 6(23% ) 3(27% )

3(20% ) 4(15°I0) 0

0 5(19°/0) 0

0 2(8% ) 0

14 (27%)

23 (44%)

10(19% )

7(13% )

5(10% )

2(4% )

Table 7 Results of ophthahnological follow-up examination in different treatment groups. Treatment method

PerEnophthalmos manent diplopia ~2 mm <2 mm

tnternaIwiring Antralpacking Non-fixation

3 (20%) 2(8% ) 0

3 (20%) 4(16% ) 1 (9%)

Total

5 (10%)

8(15%)

Exophthalmos

Palpebral fissure Decreased [ncreased a) nar- b) short-a+b c) wid- d) prorowed cncd ened longed

4 (27%) 1 (7%) 1 7(27% ) 4(16% ) 3 2(18°/0) 2(18% ) 0 13 (26%)

7 (13%)

4

Cosmetically noticeable

0 1 0

1 3 1

0 4 0

0 0 1

2 (13%) 5(19% ) 2(18% )

1

5

4

i

9 (17%)

Table 8 Most significant radiographic findings in different treatment groups. Finding a) b) c) d) e) f) g) h) i)

Zygoma and frontal arch depressed Fracture or bend in middle or dorsal part of arch Antrum narrowed or curve in lower part Thickening in roof or lateral wall of antrum Depression of orbital floor Open zygomatico-frontal suture Thickening of mucosa in antrum Difference in orbital diameter ~ 2 mm Position good - finding normal

Findings/patients

Results A comparison of hospital stays required by each treatment method used in the groups of zygomatic fractures with and without associated injuries is presented in Table 5. Only pure zygomatic fractures were suitable for comparison. The limitation of the maximal mouth opening and asymmetry in the lateral movements in the incisor region are presented in Table 6. W h e n the maximal opening of the mouth was below 40 ram, a _>= 2-ram wide asymmetry of the lateral move-

Internal wiring 4(27% ) 2(13% ) 5(33%) 2(13% ) 3 (20%) 2(13% ) 3(20% ) 5(33%) 5 (33%) 26/15

Antral packing 6(23% ) 2(8% ) 11 (42%) 9(35% ) 9 (35%) 4(15% ) 1 (4%) 11 (42%) 3 (12%) 53/26

Nonfixation 2(18% ) 3(27% ) 3(27%) 2(18% ) 1 (9°Io) 2(18% ) 1 (9%) 2(18%) 3 (27%) 16/I 1

ments occurred in 790/0 of these patients, whereas such an asymmetry was present in only 440/0 of the whole study. In cases of fracture of the zygomatic arch, the lateral movement of the mouth was always restricted toward the affected side, while in the entire study no differences were detectable between the sound and affected side. In 22 cases (42°/0), changes in sensibility were found in the skin area supplied by the infra-orbital nerve. In 5 cases (10°/0.), sensibility was entirely

Treatment of Zygomatic Fractures

111

Fig. 1 Antrum packed with plastic tubing after repositioning. Position of zygoma good, but plastic packing not tight enough.

Fig. 2 Internal wiring fixation with fractured orbital margins in good position, Lower part of zygoma depressed. Typical curve due to depression of lateral wall of maxillary sinus. Lower part of the sinus narrower than on the sound side.

absent. These cases belonged to the antral packing group. In this group, there was also more hypoand hypersensibility (380/0) than in the other treatment groups. A total of 570/0 of the cases in the antral packing group had sensibility disturbances. Without doubt, recurrent purulent sinusitis had occurred postoperatively in one patient only in the antral packing group. In the antral packing group the cheek-bone was noticeably depressed in 2 cases. In connection with the primary injury, diplopia was detected in 14 patients (270/0). At follow-up examination, diplopia was detected in 5 cases, which is 100/o of the entire series and 360/0 of those patients in whom diplopia was found primarily. Of these 5 cases, 3 (200/0) were of the internal wiring fixation group and 2 (80/0) of the antral packing group. The patients treated without fixation had no diplopia at all. In one case only, diplopia extended to the central visual field, while in the other cases diplopia was found in the peripheral area. Enophthalmos has developed in 21 cases (41O/o), of which 8 (15o/0,) were of marked degree (~ 2 mm). Exophthahnos was detected in 7 cases (130/o). There was slightly more asymmetry in the position of the globe when compared with the

sound side in the antral packing group than in the other groups, while the internal wiring fixation group demonstrated slightly more enophthalmos of marked degree. In 9 cases (170/o), the size and shape of the palpebral fissure was found to be cosmetically disturbing. Here, the dislocation of the lateral palpebral ligament was found to be the cause of the manifestation of this deformation. In one case only, the position of the margin of the lower eyelid had changed (ectropion). Changes in the size of the palpebral fissure were most usual in the antral packing group (400/0) compared with 180/o in the non-fixation group and 13°/o in the internal wiring group. The inferior orbital rim was in 7 cases lower and in 2 cases higher than that onthe sound side. Cosmetic defects in the face (such as scars, depression of the zygoma, altered size and shape of the palpebral fissure) were present in 270/0 of the subjects treated with antral packing, in 180/0 of those treated with non-fixation and in 13% of those treated with internal wiring fixation. The visual acuity was unchanged in all patients indicating absence of permanent intra-ocular damage.

112

M. Altonen, A. Kohonen, K. Di&hoff

Fig. 3 Case treated with antral packing. Zygomaticofrontal suture has remained open. Depressed lower part of zygoma. Maxillary sinus narrowed and bone in its lateral wall thickened.

Fig. 4 Internal fixation has failed. Entire zygoma fallen downward. Narrowing of maxillary sinus, maximal diameter of orbit increased compared with sound side.

Isolated changes, their number and percentage of subjects in each treatment group is presented in Table 8. Change a) is best revealed by the axial (Fig. 5) and lateral projections, change b) being most ctearly visible in the axial X-ray and changes c-g either in the antero-posterior or occipito-mental X-ray (Figs. 2-4). Change h) was detected from a postero-anterior X-ray, by measuring the longest distance of the orbital walls from the upper medial corner to the lower lateral corner (Fig. 4). Discussion

Fig. 5 Zygoma and anterior part of zygomatic arch depressed. Case treated with antra[ packing.

Table 8 records changes revealed by radiography. In the antral packing group these were approx. 2 changes per case, in the internal wiring fixation group 1.7 changes per case, and in the non-fixation group 1.5 changes per case. The majority (33°/0) of normal findings was in the internal wiring group, the next being the nonfixation group (270/0), followed by the antral packing group (120/0).

The present patient material remained relatively small, because internal wiring fixation has been more extensively used only during the previous four years. It would have been preferable to select the subjects for the groups to be compared from the same period. A number of patients had to be excluded because their injuries were too complicated, among other things, bilateral dislocation of the zygoma. The 3 Le Fort III fractures included had displacement of the zygomatic bone only on the side to be examined. Sixty per cent of the cases in the internal wiring group were high-speed traffic injuries, the corresponding percentage in the other groups being only 200/0 and 90/o. As the number of high-speed accidents increases, so does the complexity

Treatment of Zygomatic Fractures of the injuries (Dawson 1962). Not only is there a multiplicity of associated injuries, but the maxillary fractures are more complex and there are fewer fractures at one level alone (Morgan et al. 1972). In the internal wiring group there were also a greater number of fractures of other facial bones and head injuries. Evidently, the patients in this group had more severe injuries than those in the other groups. The average hospital stay for treatment with antral packing was longer than for other treatments. The patients were kept in hospital for the entire tamponing period, for 7 to 20 days, which is probably not always necessary. Mouth opening less than 40 mm may be regarded as limited. In zygomatic injuries, movement of the mandible is impeded, if the zygomatic bone is displaced backward or the zygomatic arch inward. In the present series, 4 out of the 14 with a mouth opening of less than 40 man had one or other of these displacements, while as many patients demonstrated fully normal findings in radiographs. In the internal wiring fixation group, which included the majority of associated injuries, the occurrence of restriction of mouth opening was relatively higher, including more subjects of advanced age than young subjects. On the basis of the present material it appears that restriction of opening is more often associated with long-term immobilisation and probably a deficient rehabilitation of functions than a slight remaining displacement. The majority of asymmetry in lateral movements was also found in the internal wiring fixation group. In fractures of the arch, lateral movement was restricted to the affected side. None of the patients found this restriction to be a disability. The regeneration capacity of the infraorbital nerve is generally regarded as good (Hogeman 1956, Menke 1956), but the exact reposition of fragments (Menke 1956) or at least the freeing of the nerve from the pressure of fragments is the main requirement for rapid regeneration. In the present series, antral packing has given the poorest result for meeting this requirement. All cases with no restoration of sensibility (10°/0 of the entire group) belonged to this fixation group. This group also showed hypo- and hypersensibility more often. These, however, may be an intermediate stage on the way to recovery.

113 Confirmed recurrent sinusitis occurred in one patient only, who belonged to the antral packing group. At radiographical follow-up examination, the internal wiring group showed a slight swelling of the mucosa of the maxillary sinus more often than the other groups. The present results support the view that infection of the mucosa of the maxillary sinus is especially rare when antibiotics are given prophylactically (Luhr 1967). The majority of cosmetically disappointing treatment results appeared in the antral packing group. The patients on whom reduction alone was performed, obviously had less severe injuries and showed the smallest number of cosmetically disappointing results. In 2 cases, the cosmetically disappointing scars were due to the laceration caused by the injury. Diplopia associated with a fresh zygomaticomaxillary compound fracture has been detected in 8 to 15 per cent (Mansfield 1948, Schjelderup 1950a, Barclay 1958, Nysinch 1960, Knight and North 1961). Permanent diplopia has been detected in 15 to 31 per cent (HStte 1970, Dickho[~ 1975). The present study supports the earlier observations that diplopia associated with a primary injury is prone to become permanent in 30 to 40 per cent notwithstanding treatment given (Schjelderup 1950b, Barclay 1958 and Dichho[[

1975). The higher occurrence of permanent diplopia in the internal wiring group may be the consequence of more severe primary injuries in this group (Hakelius and Pont~n 1974). The occurrence of diplopia in the present series was not in conformity with Knight and North's (1961) suggestions. In the present study, permanent diplopia was found in fracture types III, V and VI. A radiographical finding is poor evidence of a possible occurrence of diplopia. Diplopia does not automatically correlate with the extent and degree of displacement of the fracture. In the present cases, the most probable cause of diplopia was mechanical and the site of the injury peripheral. The dmnges in the position of the globe were in conformity with corresponding ophthalmological studies: 33-460/o enophthalmos and 3-8o/0 ex. ophthatmos (HStte 1970, Dichhoff 1975). There were no significant differences between the different treatment groups, although the majority with

114

M. Altonen, A. Kohonen, K. Dickhoff

enophthalnms of marked degree occurred in the internal wiring group. There are few reports concerning the incidence of late or permanent intrabulbar changes after facial injury. Depending on the type of injury, vision has been found to have decreased in 7 to 10% of cases (Pfeiffer 1943, Obear 1967, Dickhoff 1975). In zygomatico-maxillary fractures the impact energy is mainly directed to the cheek-bone, whereby the globe and the optical nerve are not injured. None of the present subjects had decreased vision because of injury. The radiographic examination revealed different types of deformities, which do not all have clinical significance, but they depict the accuracy of reduction, and therefore they can be used in comparing treatment methods. Fixation by antral packing resulted more often in deformations, such as narrowing of the antrum, indicating displacement of the zygomatic bone. The packing material used might be too elastic and not firm enough, and does not meet Wassmund's (1956) recommendation of a non-elastic packing material which has to be tightly packable and cause constant pressure.

Conclusions The primary treatment of zygomatic fractures is of crucial significance.

The present series did not enable the authors to draw any statistical conclusions. It can be concluded from the results, however, that of the fixation methods compared, the internal wiring method has given the most accurate results in reduction at radiographic examination. At clinical examination, this method proved to be superior when comparing hospital stay, restoration of function o!: the infraorbital nerve, position of the globe, symmetry of the palpebral fissures and the cosmetic result. In the antral pa&ing group, the result was better when comparing movements of the mouth and occurrence of permanent diplopia. In simple fractures, mere reduction often leads to a satisfactory result and hospital stay is then a short one. Elucidation of presenting the clinical picture at the primary stage is of crucial importance. A special examination form may be needed to facilitate examination of facial injuries and planning of treatment, in order to make these more consistent.

Acknowledgement The authors thank Carl Johan SjSblom, Physician-inChief, for his roentgenological assistance.

References Barclay, T. L.: Diplopia in association with fractures involving the zygomatic bone. Brit. J. plast. Surg. 11 (1958) 147 Carlson, 0., G. Mdrtensson: Fractures of the zygomatic bone. Svensk tandlfik.-T, 62 (1969) 167 Converse, J. M., B. Smith: Reconstruction of the floor of the orbit by bone graft. Arch. Ophthal. (Chic.) 44 (1950) 1 Converse, J. M., B. Smith: Enophthalmos and diplopia in fractures of the orbital floor. Brit. J. plast. Surg. 9 (1957@ 265 Converse, ]. M., B. Smith: Early treatment of orbital floor fracture. Trans. Amer. Acad. Ophthal. Otolaryng. 61 (1957b) 602 Dawson, R. L. G.: The priorities and emergency treatment of multiple injuries including maxillo facial tramna. Brit. dent. J. 113 (1962) 345 Dawson, R. L. G., G. L. Fordyee: Complex fractures of the middle third of the face and their early treatment. Brit. J. Surg. 41 (1953) 254

Di&hoff, K. J.: Unilateral orbital trauma: A clinical and follow-up study of 146 cases. Thesis, Helsinki 1975 (in press) Greenwald, H. S. Jr., A. H. Keeney, G. M. Shannon: A review of 198 patients with orbital fractures. Amer. J. Ophthal. 78 (1974) 655 Hakelius, L., B. Pontdn: Results of immediate and delayed surgical treatment of facial fractures with diplopia. J. max.-fac. Surg. 1 (1973) 150 Hogeman, K.-E.: Die Brfiche des Jochbeins und Jochbogens. Fortschr. Kiefer- u. Gesichtschir. 2 (1956) 58 H6tte, H. H, A.: Orbital fractures. Van Gorcum, Assen (Netherlands) 1970 Kiviranta, U.: Silm/~kuopan pohjan painemurtuma (blow-out fracture). Duodecim 89 (1966) 665 Knight, J. S., J. F. North: The classification of malar fractures: an analysis of displacement as a guide to treatment. Brit. J. p!ast. Surg. 13 (1961) 381 Luhr, H.-G.: Zur Frage der Revision der Kiefcrh6hlc bei Oberkiefer- und Jochbeinfrakturen. Dts&. zahn/irztl. Z. 22 (1967) 905

Treatment of Zygomatic Fractures

Lund, K.: Fractures of the zygoma: a follow-up study on 62 patients. J. oral. Surg. 29 (1971) 557 Mansfield, O. T.: Fractures of the malar-zygomatic compound. Brit. J. plast. Surg. 1 (1948) 123 McCoy, ]., R. A. Chandler, C. G. Magnan, ]. R. Moore, G. Siemsen: An analysis of.-facial fractures and their complications. Plast. reconstr. Surg. 29 (1962) 381 Menhe, E.: Zur Behandlung der Jochbeinfrakturen. Fortschr. Kiefer- u. Gesichtschir. 2 (1956) 58 Morgan, B. D. G., D. K. Madan, ]. P. C. Bergerot: Fractures of the middle third of the face - a review of 300 cases. Brit. J. plast. Surg. 25 (1972) 147 Miiller, W.: H/iufigkeit, Sitz und Ursachen der Gesichtssch/idelfrakturen. In: E. Reichenbach: Traumatologie im Kiefer-Gesichts-Bereich. Barth, Leipzig 1969 Nysinch, ]. G.: Zygomatico-maxillaire fracturen. Thesis, Utrecht (1960) 122 Obear, M. F.: Diagnosis and management of the floor of the orbit. In: B. Smith, J. M. Converse: Plastic and reconstructive surgery of the eye and adnexa, proc. 2nd. Internat. Symposium. Mosby, St. Louis 1967 Oikarinen, V. ]., M. Malmstr6m: Jaw fractures. Suom. Hammaslfi~ik. Toim. 65 (1969) 95 Pape, K.: Die Frakturen des lateralen Mittelgesichts und ihre Behandlung. In: E. Reichenbach: Traumatologie im Kiefer-Gesichts-Bereich. Barth, Leipzig 1969

115

P/eiffer, R.: Traumatic enophthalmos. Arch. Ophthal. (Chic.) 30 (1943) 718 Pfeiffer, R. L.: Roentgenography of fracture. In: Plastic and reconstructive surgery of the eye and adnexa. Butterworths, Washington 1962 Rowe, N. L., H. C. Killey: Fractures of the facial skeleton. Livingstone, Edinburgh 1955 Schjelderup, H.: Some considerations concerning traumatic diplopia. Acta ophthal. (Kbh.) 28 (1950a) 377 Schjelderup, H.: Fracture of the upper and middle thirds of the facial skeleton. Acta clair, scand, 99 (1950b) 445 Schuchardt, K., N. Schwe~r~zer, B. Rottke, ]. Lentrodt: Ursachen, Hfiufigkeit und Lokalisation der Frakturen des Gesichtssch/idels. Fortschr. Kiefer- u. Gesichtschir. 11 (1966) Tajima, S., C. Sugimoto, R. Tanino, T. Ohshiro, T. Harashina: Surgical treatment of malunited Fracture of zygoma with diplopia and with comments on blow-out fracture. J. max.-fac. Surg. 2 (1974) 201 Wassmund, M.: Verletzungen der Weichteile, der Nebenh6hlen und der Orbita bet den Brfichen des Gesichtsskelettes. Fortschr. Kiefer- u. Gesichtschir. 2 (1956) 62 Mikko Altonen, M.D., D.M.D., Deparlme~tof Oral Surgery, h~stitute of Dentistry, University of Helsinki. Finland