Short communications & case reports
Aneurysmal bone cyst of the maxilla Johan P. Reyneke,B.Ch.D.,* Pretoria, Republic of South AJiica DEPARTMENT OF MAXILLO-FACIAL AND ORAL SURGERY, UNIVERSITY OF PRETORIA Presentedis a caseof large aneurysmalhone cyst of the maxilla, associatedwith an impacted canine tooth. It is thought that signs of dilaceration at the apex of the tooth might he significant, and might throw light on the point in time at which the lesion developed.
he aneurysmal bone cyst was first identified as a separateclinicopathologic entity by T Jaffe and Lichtenstein’ in 1942, but many caseshave subsequentlybeen reported in the literature. The lesions have been observed in nearly every part of the skeleton, although more than 50 percent of them occur in long bones and the vertebral column. Lesions are frequently seen in the clavicle, rib, innominate bone, skull, and bones of the hands and feet. The lesion is relatively rare in the jaws, and it was 16 years after the first report by Jaffe and Lichtenstein that Bernier and Bhaskar2reported two casesthat occurred in the facial bones. In 1971, Daugherty and Eversole, in a review of the literature, found seventeenreported casesof aneurysmal bone cysts of the jaws. To these must be added those subsequentlyreported by Ellis and Walters4in 1972 and by OliveIS in 1973. The aneurysmal bone cyst is a non-neoplastic, expansile, solitary lesion, the main feature of which is replacement of bone by spongy fibro-osseous tissue that contains blood-filled cavernous vessels or sinusoidal blood-filled spaces.5It is not a true cyst. Expansion and tendernessof the involved bone are usually the first signs. The lesion is localized, and development may take place within a few weeks to several years. It is usually found in patients younger than 20 years of age and showsno marked sex predilection . ROENTGENOGRAPHIC
FEATURES
The aneurysmal bone cyst presents as a well-circumscribed radiolucent lesion with marked bone expansion. In the facial bones, the expanded bone usually appearsto be cystic, with a “honeycomb” or “soap bubble” aspect.6 It exhibits a similarity to the *Senior Resident, Department of Maxillo-Facial and Oral Surgery, Oral and Dental Hospital, University of Pretoria. OIl30-4220/78/0345-044441$00.70/0 @ 1978The C. V. MosbyCo.
441
442
Oral Surg. March, 1978
Reyneke
Fig. 1. Clinical appearanceof the patient. Note the swelling in the right maxilla which lifts the right nostril.
hemangioma, central myxoma, giant-cell lesion, and some of the odontogenic cysts, so that a definite radiographic diagnosis is not always possible (see Figs. 2 and 3). HlSfOLOGlC
FEATURES
Microscopically, the lesion consistsof a fibrous connective-tissuestromathat contains numerous young fibroblasts as well as multinucleated giant cells with a patchy distribution. The connective tissue is richly vascularized and many cavernous or sinusoidal blood-filled spacesare present. Varying amounts of hemosiderin are present and, invariably, there is new osteoid and bone formation. Solid zones may have histologic features common to other fibro-osseouslesions, and the presenceof cavernousspacesis of great importance in the diagnoses. CASE REPORT
An 1Kyear-oldNegroboy wasreferredto the Departmentof Maxillo-FacialandOral Surgery of the Kalafong Hospital in Pretoria. His main complaint concerned a swelling over the right maxillary area, which was tender to palpation. He had become aware of the swelling approximately 18 months previously. He could not recall having experienced any trauma at any time previously. No anesthesia or paresthesia was present over the area. The past medical history was negative. The findings of the general physical examination were negative, except for the swelling in the right maxilla. Extraoral examination revealed in the right maxilla, a firm swelling which lifted the right nostril (Fig. 1). Intraoral examination revealed a relatively firm swelling in the right canine fossa and central incisor area, extending from the maxillary left central incisor in the median plane to the premolar region on the right side. On palpation, the lesion produced a typical “eggshell” crepitus.
Volume 45 Number 3
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443
Fig. 2. Occlusal radiograph of the maxilla, illustrating the extent of the lesion in the palate
Fig. 3. Panoramicradiograph of the jaws. Note the angulation on the apical third of the root of the impacted canine (CD). The displacementof the involved teeth can clearly be seen.
On the palatal side a swelling was present, extending from the upper right first molar to the upper left lateral incisor. No crepitus was presentin this area. The mucosaover the areawas normal. The upper right central and lateral incisors and the upper right central incisor were displaced and relatively mobile, whereasthe upper right canine was clinically absent.The upper right incisors and the upper left central incisor were vital. On roentgenologic examination, panoramic, occipito-mental, and occlusal radiographs(Figs. 2 and 3) revealeda unilocular, oval, radiolucent lesion associatedwith an uneruptedcanine tooth. The impacted canine was displaced and the root showed signs of dilaceration. The roots of upper right
444
Reyneke
Oral Surg. March, 1978
Fig. 4. Aneurysmal hone cyst. Multinucleated giant cells (CC) dispersedin a stromaof connective tissue(CT)
with multiple fibroblasts present. Developing capillary (DC) as well as vascular space(F’S)filled with erythrocytes are illustrated. (Magnification, X600.)
incisors and the upper left central incisor were displaced toward the left side, whereasthe roots of
the upper right premolars were displaced distally. Treatment
The patient was hospitalized, and on the sameday the swollen areain the maxilla was aspirated, with approximately 5 ml. of serosanguineousfluid being obtained. After premeditation with 15 mg. of diazapam (Valium) syrup, the patient was given a local anesthetic of 2 percent mepivacaine (Carbocaine). A buccal mucoperiostealflap was raised and accessto the lesion was obtained by carefully removing somevery thin bone with rongeursforceps. An incisional biopsy was performed, with removal of a portion of tissue approximately 1.Oby 0.5 cm. in size. The lesion was cystic but with no epithelial capsule, and the biopsy specimen was red-brown with a soft texture. No significant bleeding occurred and the flap was closed with 4-O black silk sutures. The histologic examination revealed a connective-tissue stroma in which multiple fibroblasts were present. Many cavernous blood-filled spaces were seen and numerous multinucleated giant cells were dispersedthroughout the connective tissue stroma (Figs. 4 and 5). A provisional diagnosis of aneurysmalbone cyst was madebut the possibility of a giant-cell or hyperparathyroid tumor existed. Urinalysis, blood count, and serum calcium and phosphorus, and serum alkaline phosphatase studies were done, with all findings being within normal limits. Operation
Ten days after the biopsy, the patient was admitted to the operating room, where nasoendotracheal intubation was used to administer a general anesthetic. The patient was preparedand the surgical field was draped in the usual manner. A mucoperiostealflap was raised that extendedfrom the upper right lateral incisor to the upper
Aneurysmal bone cyst of maxilla
445
Fig. 5. Aneurysmal bone cyst showing giant cells (A), sinusoidal space (B), and osteoid (0) in a fibrovascular stroma (C). (Magnification,
x
160.)
right first premolar. The thin layer of bone that coveredthe lesion was easily removedwith rongeurs forceps. Becauseof the soft, spongy texture of the lesion, it could not be removedin toto. The tissue had a red-brown, spongy, “liver-like” appearance.No mentionablebleeding was experiencedat the periphery; but in the central part, excessivebleeding was encountered,with the blood “welling up” from the tissue. The tumor masswas separatedfrom the underlying bone without difficulty and all the cystic tissue was removed from the bone cavity by careful curettage. Despite a sharp bend on the apical third of the root, the impacted canine tooth was removed quite easily from the roof of the bone cavity, with the use of a Warwick Jameselevator. The sharp curve of the root correspondedto that seenon the panoramic radiograph (Fig. 3). Hemostasiswas accomplishedwith a gauze pack and cauterization of the remaining bleeding points. After the gauzewas removed, gypsum was usedto fill the cavity. The shambony edgeswere trimmed, the flap was replaced, and the incision was suturedwith interrupted 4-Oblack silk sutures. An extraoral pressure-dressingwas placed over the upper lip. Erythromycin (Ilosone), 500 mg. every 6 hours, was prescribed. A moderateamount of postoperative edema was present, but this cleared after the fifth day. Further postoperativerecovery was uneventful. Antibiotic coveragewas discontinued after 7 days, and the patient was dischargedon the tenth postoperativeday. The information obtained from the operation, and the histologic featuresof the lesion enabled the pathologists to make a final diagnosis of aneurysmal bone cyst (Figs. 4 and 5). DISCUSSION
Although many cases of aneurysmal bone cyst have been reported, few have involved the facial bones, especially the maxilla. The cause of this lesion is still unknown and controversial. Various hypotheses exist: Lichtenstein’ proposed that a persistent alteration in the local hemodynamics leads to increased venous pressure and subsequent development of a dilated and enlarged vascular bed in the transformed bone area. Biesecker and
446
Reyneke
Oral Surg.
March. 1978
his colleague9 found in their series of sixty-two casesof aneurysmal bone cysts that a primary bone lesion was present in 32 percent of them. They proposed that a primary lesion of bone initiated an osseousarteriovenous malformation and thereby created, hemodynamically, a secondary reactive lesion of bone which is known as the aneurysmal bone cyst. The hypothesis that the aneurysmal bone cyst is produced by secondarypathologic changes in a primary lesion is not supported by Donaldson.s Jaffe and Lichtenstein’ reported caseswhich showed that aneurysmal bone cysts can be grafted onto a previous lesion, thereby constituting a secondaryrather than a primary lesion. Trauma that produces medullary hemorrhageis often suggestedas the causative factor. The lesion then representsan exuberant attempt at repair of a hematomaof bone. It is postulatedthat the hematomamaintains a circulatory connection with the damagedvessel. The slow flow of blood through the lesion accountsfor the “welling-up” of blood when the lesion is entered surgically.6 Although the observation was made that the history of trauma was not frequent, the casewhich I have presentedsupports the above-mentioned hypothesis. In this case, the presenceof the impacted canine tooth in the cystic cavity might be of great significance, since there was a sharp angulation or bend in the apical third of the root (dilaceration). This fact might help to shed light on the point in time at which the lesion developed. Dilaceration is thought to be due to trauma during the period in which the tooth is forming, with the result that the position of the calcified portion of the tooth is changed and the remainder of the tooth is formed at an angle. The area of the angulation dependsupon the amount of root formed when the injury occurs.’ In the casereported, the “injury” is estimatedto have occurred when the patient was 10 years old. Thus the lesion must have developed within the subsequent8 years. The hypothesis of Bernier and Bhaska? is acceptableon the basis of the reportedcase.In their view, the walls representorganized or canalized portions of a hematomaand, therefore, there is a relationship between the aneurysmal bone cyst and the giant-cell granuloma. Trauma that causesa hematomaand replacementof the hematomain bone by connective tissue is representedin both lesions. If a circulatory connection with the damagedvesselis maintained in the hematoma, an aneurysmal bone cyst results. If the connection is blocked, a giant-cell granuloma develops. CONCLUSION
A large aneurysmal bone cyst of the maxilla has been reported. The presenceof an impacted canine tooth, showing signs of dilaceration, in close proximity to the lesion, is thought to shed light on the point in time at which the lesion developed. I wish to thank Professor J. E. Seeligerfor his kind assistance in preparingthis article,aswell as Mrs. E. Cilliers and Mr. J. Nell for their skillful photography. My sincere thanks are due also to Professor J. G. Duvenage for permission to use material from his department.
REFRRENCES
1. Jaffe, H. L., and Lichtenstein, L.: Solitary Unicameral Bone Cyst, With Emphasison the RoentgenPicture, the Pathology and the Pathogenesis,Arch. Surg 46: 1004, 1942. 2. Bemier, J. L., and Bhaskar, S. N.: Aneurysmal Bone Cyst of the Mandible, ORAL SIJRG. 11: 1018, 1958. 3. Daugherty, J. W., and Eversole, L. R.: Aneurysmal Bone Cyst of the Mandible: Report of a Case, J. Oral. Surg. 29: 737, 1971.
Aneurysmal bone cyst of maxilla
447
4. Ellis, D. J., and Walters, P. J.: Aneurysmal Bone Cyst of the Maxilla, ORAL SURG. 34: 26, 1972. 5. Oliver, L. P.: Aneurysmal Bone Cyst: Report of a Case, ORAL SURG. 35: 67, 1973. 6. Shafer, W. G., Hine, M. K., and Levy, B. M.: A Textbook of Oral Pathology, ed. 3, Philadelphia. 1958.W. B. SaundersCompany, pp. 38, 138-140. 7. Lichtenstein, L.: Aneurysmal Bone Cyst. A Pathological Entity Commonly Mistaken for Giant-cell Tumor and Occasionally for Hemangioma and Osteogenic Sarcoma, Cancer 3: 279, 1950. 8. Biesecker, J. C., et al.: Aneurysmal Bone Cyst: A Clinicopathologic Study of 66 Cases, Cancer 26: 615, 1970. 9. Donaldson, W. E.: Aneurysmal Bone Cyst, I. Bone Joint Surg. Am. 44: 25, 1962. Reprint requests to:
Dr. J. P. Reyneke Department of Maxillo-Facial and Oral Surgery P. 0. Box 1266 Pretoria, South Africa 0001
INFORMATION FOR AUTHORS Most of the provisions of the Copyright Act of 1976 became effective on January 1, 1978. Therefore, all manuscripts must be accompanied by the following statement, signed by each author: “The undersigned author(s) transfers all copyright ownership of the manuscript entitled (title of article) to The C. V. Mosby Company in the event the work is published. The author(s) warrants that the article is original, is not under consideration by another journal, and has not been previously published.” Authors will be consulted, when possible, regarding republication of their material.
Aneurysmal bone cyst of the maxilla Johan P. Reyneke,B.Ch.D.,* Pretoria, Republic of South AJiica DEPARTMENT OF MAXILLO-FACIAL AND ORAL SURGERY, UNIVERSITY OF PRETORIA Presentedis a caseof large aneurysmalhone cyst of the maxilla, associatedwith an impacted canine tooth. It is thought that signs of dilaceration at the apex of the tooth might he significant, and might throw light on the point in time at which the lesion developed.
he aneurysmal bone cyst was first identified as a separateclinicopathologic entity by T Jaffe and Lichtenstein’ in 1942, but many caseshave subsequentlybeen reported in the literature. The lesions have been observed in nearly every part of the skeleton, although more than 50 percent of them occur in long bones and the vertebral column. Lesions are frequently seen in the clavicle, rib, innominate bone, skull, and bones of the hands and feet. The lesion is relatively rare in the jaws, and it was 16 years after the first report by Jaffe and Lichtenstein that Bernier and Bhaskar2reported two casesthat occurred in the facial bones. In 1971, Daugherty and Eversole, in a review of the literature, found seventeenreported casesof aneurysmal bone cysts of the jaws. To these must be added those subsequentlyreported by Ellis and Walters4in 1972 and by OliveIS in 1973. The aneurysmal bone cyst is a non-neoplastic, expansile, solitary lesion, the main feature of which is replacement of bone by spongy fibro-osseous tissue that contains blood-filled cavernous vessels or sinusoidal blood-filled spaces.5It is not a true cyst. Expansion and tendernessof the involved bone are usually the first signs. The lesion is localized, and development may take place within a few weeks to several years. It is usually found in patients younger than 20 years of age and showsno marked sex predilection . ROENTGENOGRAPHIC
FEATURES
The aneurysmal bone cyst presents as a well-circumscribed radiolucent lesion with marked bone expansion. In the facial bones, the expanded bone usually appearsto be cystic, with a “honeycomb” or “soap bubble” aspect.6 It exhibits a similarity to the *Senior Resident, Department of Maxillo-Facial and Oral Surgery, Oral and Dental Hospital, University of Pretoria. OIl30-4220/78/0345-044441$00.70/0 @ 1978The C. V. MosbyCo.
441
442
Oral Surg. March, 1978
Reyneke
Fig. 1. Clinical appearanceof the patient. Note the swelling in the right maxilla which lifts the right nostril.
hemangioma, central myxoma, giant-cell lesion, and some of the odontogenic cysts, so that a definite radiographic diagnosis is not always possible (see Figs. 2 and 3). HlSfOLOGlC
FEATURES
Microscopically, the lesion consistsof a fibrous connective-tissuestromathat contains numerous young fibroblasts as well as multinucleated giant cells with a patchy distribution. The connective tissue is richly vascularized and many cavernous or sinusoidal blood-filled spacesare present. Varying amounts of hemosiderin are present and, invariably, there is new osteoid and bone formation. Solid zones may have histologic features common to other fibro-osseouslesions, and the presenceof cavernousspacesis of great importance in the diagnoses. CASE REPORT
An 1Kyear-oldNegroboy wasreferredto the Departmentof Maxillo-FacialandOral Surgery of the Kalafong Hospital in Pretoria. His main complaint concerned a swelling over the right maxillary area, which was tender to palpation. He had become aware of the swelling approximately 18 months previously. He could not recall having experienced any trauma at any time previously. No anesthesia or paresthesia was present over the area. The past medical history was negative. The findings of the general physical examination were negative, except for the swelling in the right maxilla. Extraoral examination revealed in the right maxilla, a firm swelling which lifted the right nostril (Fig. 1). Intraoral examination revealed a relatively firm swelling in the right canine fossa and central incisor area, extending from the maxillary left central incisor in the median plane to the premolar region on the right side. On palpation, the lesion produced a typical “eggshell” crepitus.
Volume 45 Number 3
Aneurysmal bone cyst of maxilla
443
Fig. 2. Occlusal radiograph of the maxilla, illustrating the extent of the lesion in the palate
Fig. 3. Panoramicradiograph of the jaws. Note the angulation on the apical third of the root of the impacted canine (CD). The displacementof the involved teeth can clearly be seen.
On the palatal side a swelling was present, extending from the upper right first molar to the upper left lateral incisor. No crepitus was presentin this area. The mucosaover the areawas normal. The upper right central and lateral incisors and the upper right central incisor were displaced and relatively mobile, whereasthe upper right canine was clinically absent.The upper right incisors and the upper left central incisor were vital. On roentgenologic examination, panoramic, occipito-mental, and occlusal radiographs(Figs. 2 and 3) revealeda unilocular, oval, radiolucent lesion associatedwith an uneruptedcanine tooth. The impacted canine was displaced and the root showed signs of dilaceration. The roots of upper right
444
Reyneke
Oral Surg. March, 1978
Fig. 4. Aneurysmal hone cyst. Multinucleated giant cells (CC) dispersedin a stromaof connective tissue(CT)
with multiple fibroblasts present. Developing capillary (DC) as well as vascular space(F’S)filled with erythrocytes are illustrated. (Magnification, X600.)
incisors and the upper left central incisor were displaced toward the left side, whereasthe roots of
the upper right premolars were displaced distally. Treatment
The patient was hospitalized, and on the sameday the swollen areain the maxilla was aspirated, with approximately 5 ml. of serosanguineousfluid being obtained. After premeditation with 15 mg. of diazapam (Valium) syrup, the patient was given a local anesthetic of 2 percent mepivacaine (Carbocaine). A buccal mucoperiostealflap was raised and accessto the lesion was obtained by carefully removing somevery thin bone with rongeursforceps. An incisional biopsy was performed, with removal of a portion of tissue approximately 1.Oby 0.5 cm. in size. The lesion was cystic but with no epithelial capsule, and the biopsy specimen was red-brown with a soft texture. No significant bleeding occurred and the flap was closed with 4-O black silk sutures. The histologic examination revealed a connective-tissue stroma in which multiple fibroblasts were present. Many cavernous blood-filled spaces were seen and numerous multinucleated giant cells were dispersedthroughout the connective tissue stroma (Figs. 4 and 5). A provisional diagnosis of aneurysmalbone cyst was madebut the possibility of a giant-cell or hyperparathyroid tumor existed. Urinalysis, blood count, and serum calcium and phosphorus, and serum alkaline phosphatase studies were done, with all findings being within normal limits. Operation
Ten days after the biopsy, the patient was admitted to the operating room, where nasoendotracheal intubation was used to administer a general anesthetic. The patient was preparedand the surgical field was draped in the usual manner. A mucoperiostealflap was raised that extendedfrom the upper right lateral incisor to the upper
Aneurysmal bone cyst of maxilla
445
Fig. 5. Aneurysmal bone cyst showing giant cells (A), sinusoidal space (B), and osteoid (0) in a fibrovascular stroma (C). (Magnification,
x
160.)
right first premolar. The thin layer of bone that coveredthe lesion was easily removedwith rongeurs forceps. Becauseof the soft, spongy texture of the lesion, it could not be removedin toto. The tissue had a red-brown, spongy, “liver-like” appearance.No mentionablebleeding was experiencedat the periphery; but in the central part, excessivebleeding was encountered,with the blood “welling up” from the tissue. The tumor masswas separatedfrom the underlying bone without difficulty and all the cystic tissue was removed from the bone cavity by careful curettage. Despite a sharp bend on the apical third of the root, the impacted canine tooth was removed quite easily from the roof of the bone cavity, with the use of a Warwick Jameselevator. The sharp curve of the root correspondedto that seenon the panoramic radiograph (Fig. 3). Hemostasiswas accomplishedwith a gauze pack and cauterization of the remaining bleeding points. After the gauzewas removed, gypsum was usedto fill the cavity. The shambony edgeswere trimmed, the flap was replaced, and the incision was suturedwith interrupted 4-Oblack silk sutures. An extraoral pressure-dressingwas placed over the upper lip. Erythromycin (Ilosone), 500 mg. every 6 hours, was prescribed. A moderateamount of postoperative edema was present, but this cleared after the fifth day. Further postoperativerecovery was uneventful. Antibiotic coveragewas discontinued after 7 days, and the patient was dischargedon the tenth postoperativeday. The information obtained from the operation, and the histologic featuresof the lesion enabled the pathologists to make a final diagnosis of aneurysmal bone cyst (Figs. 4 and 5). DISCUSSION
Although many cases of aneurysmal bone cyst have been reported, few have involved the facial bones, especially the maxilla. The cause of this lesion is still unknown and controversial. Various hypotheses exist: Lichtenstein’ proposed that a persistent alteration in the local hemodynamics leads to increased venous pressure and subsequent development of a dilated and enlarged vascular bed in the transformed bone area. Biesecker and
446
Reyneke
Oral Surg.
March. 1978
his colleague9 found in their series of sixty-two casesof aneurysmal bone cysts that a primary bone lesion was present in 32 percent of them. They proposed that a primary lesion of bone initiated an osseousarteriovenous malformation and thereby created, hemodynamically, a secondary reactive lesion of bone which is known as the aneurysmal bone cyst. The hypothesis that the aneurysmal bone cyst is produced by secondarypathologic changes in a primary lesion is not supported by Donaldson.s Jaffe and Lichtenstein’ reported caseswhich showed that aneurysmal bone cysts can be grafted onto a previous lesion, thereby constituting a secondaryrather than a primary lesion. Trauma that produces medullary hemorrhageis often suggestedas the causative factor. The lesion then representsan exuberant attempt at repair of a hematomaof bone. It is postulatedthat the hematomamaintains a circulatory connection with the damagedvessel. The slow flow of blood through the lesion accountsfor the “welling-up” of blood when the lesion is entered surgically.6 Although the observation was made that the history of trauma was not frequent, the casewhich I have presentedsupports the above-mentioned hypothesis. In this case, the presenceof the impacted canine tooth in the cystic cavity might be of great significance, since there was a sharp angulation or bend in the apical third of the root (dilaceration). This fact might help to shed light on the point in time at which the lesion developed. Dilaceration is thought to be due to trauma during the period in which the tooth is forming, with the result that the position of the calcified portion of the tooth is changed and the remainder of the tooth is formed at an angle. The area of the angulation dependsupon the amount of root formed when the injury occurs.’ In the casereported, the “injury” is estimatedto have occurred when the patient was 10 years old. Thus the lesion must have developed within the subsequent8 years. The hypothesis of Bernier and Bhaska? is acceptableon the basis of the reportedcase.In their view, the walls representorganized or canalized portions of a hematomaand, therefore, there is a relationship between the aneurysmal bone cyst and the giant-cell granuloma. Trauma that causesa hematomaand replacementof the hematomain bone by connective tissue is representedin both lesions. If a circulatory connection with the damagedvesselis maintained in the hematoma, an aneurysmal bone cyst results. If the connection is blocked, a giant-cell granuloma develops. CONCLUSION
A large aneurysmal bone cyst of the maxilla has been reported. The presenceof an impacted canine tooth, showing signs of dilaceration, in close proximity to the lesion, is thought to shed light on the point in time at which the lesion developed. I wish to thank Professor J. E. Seeligerfor his kind assistance in preparingthis article,aswell as Mrs. E. Cilliers and Mr. J. Nell for their skillful photography. My sincere thanks are due also to Professor J. G. Duvenage for permission to use material from his department.
REFRRENCES
1. Jaffe, H. L., and Lichtenstein, L.: Solitary Unicameral Bone Cyst, With Emphasison the RoentgenPicture, the Pathology and the Pathogenesis,Arch. Surg 46: 1004, 1942. 2. Bemier, J. L., and Bhaskar, S. N.: Aneurysmal Bone Cyst of the Mandible, ORAL SIJRG. 11: 1018, 1958. 3. Daugherty, J. W., and Eversole, L. R.: Aneurysmal Bone Cyst of the Mandible: Report of a Case, J. Oral. Surg. 29: 737, 1971.
Aneurysmal bone cyst of maxilla
447
4. Ellis, D. J., and Walters, P. J.: Aneurysmal Bone Cyst of the Maxilla, ORAL SURG. 34: 26, 1972. 5. Oliver, L. P.: Aneurysmal Bone Cyst: Report of a Case, ORAL SURG. 35: 67, 1973. 6. Shafer, W. G., Hine, M. K., and Levy, B. M.: A Textbook of Oral Pathology, ed. 3, Philadelphia. 1958.W. B. SaundersCompany, pp. 38, 138-140. 7. Lichtenstein, L.: Aneurysmal Bone Cyst. A Pathological Entity Commonly Mistaken for Giant-cell Tumor and Occasionally for Hemangioma and Osteogenic Sarcoma, Cancer 3: 279, 1950. 8. Biesecker, J. C., et al.: Aneurysmal Bone Cyst: A Clinicopathologic Study of 66 Cases, Cancer 26: 615, 1970. 9. Donaldson, W. E.: Aneurysmal Bone Cyst, I. Bone Joint Surg. Am. 44: 25, 1962. Reprint requests to:
Dr. J. P. Reyneke Department of Maxillo-Facial and Oral Surgery P. 0. Box 1266 Pretoria, South Africa 0001
INFORMATION FOR AUTHORS Most of the provisions of the Copyright Act of 1976 became effective on January 1, 1978. Therefore, all manuscripts must be accompanied by the following statement, signed by each author: “The undersigned author(s) transfers all copyright ownership of the manuscript entitled (title of article) to The C. V. Mosby Company in the event the work is published. The author(s) warrants that the article is original, is not under consideration by another journal, and has not been previously published.” Authors will be consulted, when possible, regarding republication of their material.
