373
Australian Dental Journal, October, 1977 Volume 22, No. 5
The traumatic bone cyst
John R. Herd, M.D.Sc., L.D.S., F.R.A.C.D.S. Formerly Reader in Oral Surgery, Department of Oral Pathology and Oral Surgery, The University of Adelaide (Received for publication August, 1976)
Introduction The traumatic bone cyst affecting the mandible is a lesion that has an indeterminate aetiology. Whilst it has generally been related to the lesion usually referred t o as the unicameral bone cyst, most commonly affecting long bones, it would appear that there are certain differences in respect of mode of presentation, basic histopathology, and response to treatment that would seem to form an argument that it may be a separate entity. Certain aspects of its clinical behaviour may be related to its aetiology. The following case is reported because it appears that a gaseous component was demonstrated as being part of the contents of the lesion described. Previous suppositions in respect d the contents of these abnormalities have included references t o the possibility of the presence of gas, but to date no definite proof in support of these statements has been produced1.2. Blum T-Unusual bone cavities of the mandible: a repdrt of three cases of traumatic bone cysts. J.A.D.A., 19:2 281-301 (Feb ) 1932. 2 Whiner;. I . G.-Pronrkssive bone cavities of the mandible. A review of thesc-called traumatic bone cyst and a report of three cases. Oral Surg., Oral Med., and Oral Path., 8 : s . 903-916 (Aug.) 1955.
3
Case history
A 14-year-old, healthy Caucasian girl was referred to the Oral Surgery Clinic of the Perth Dental Hospital in March, 1969, for the investigation of an asymptomatic swelling in the region of the left mandible. This had recently been noted by the patient’s parents but no definite history related to the rate of development was available. At the initial clinical examination a slight facial asymmetry was apparent (Fig. 1). There was no other detectable oro-facial or cervical abnormality. Intra-oral examination revealed a smooth, “shelving” expansion of the buccal aspect of the mandible extending from the mesial of the first molar to the region of the unerupled third molar. The overlying mucosa was of a normal appearance, and there was no tenderness to pressure on palpation. There was no associated detectable lingual expansion. A periapical radiograph of the region showed a well-defined radiolucent area extending from the mesial of the first molar to that of the unerupted third molar (Fig. 2). This was of an even degree of radiolucency and had the appearance of a scalloping extension towards the alveolar crest between the roots of the teeth in the area. The
374
Australian Dental Journal, October, 1977
images of the periodontal spaces of these teeth were distinct from the main body of the radiolucency. Examination of lateral oblique and anteroposterior radiographs confirmed that the expansion was of a buccal nature, and showed the radiolucent
Fig. 1.-Facial
Fig. 3.-A,
asymmetry with mild expansion left mandible.
The provisional diagnosis was that of traumatic bone cyst. A decision for surgical intervention was made to confirm the provisional diagnosis. As the possibility of the presence of some gaseoiis element
Fig. 2.-Periapical radiograph left mandible. Note "scalloping" between roots of related molar teeth.
Discolouration area at distal of expanded buccal plate. B, Shift of area towards mesial
(arrows).
area to extend to the lower border of the mandible. The image of the inferior dental canal was not apparent in the region of abnormality. Vitality tests indicated that those teeth whose roots were in closest relation to the abnormal area were vital. There was no relationship of the area to the coincident impacted, unerupted second premolar.
within such lesions had been suggested it was decided to attempt the aspiration of the contents with the aim of collecting a gaseous sample. An 18 gauge needle was prepared, the bevel being removed and a saw-tooth margin prepared to enable the penetration of the overlying bone. Under general anaesthesia, a mucoperiosteal flap was reflected from the mesial of the mandibular
Australian Dental Journal, October, 1977
375
canine to the region of the third molar. The buccal expansion of the mandible in the area was apparent, but an interesting observation was the appearance of a small bluish area towards the posterior region of the clinical abnormality (Fig. 3A). The interesting observation was that, upon
Fig. X-Gas
bubble sealed within syringe (arrowed).
Fig. 4.-Aspiration needle introduced to cavity rhrough region of discolouration of buccal plate.
Fig. 7.-Buccal
bone and lining of bone cavity. A, H &
E X 40. B, H & E X 400.
Fig. 6.--Inferior neuro-vascular dental bundle traversing bone cavity (arrowed).
movement of the patient’s head, this area shifted in position (Fig. 3B). The similarity between this change and the change in position of the bubble in a spirit level was apparent. The impression was that of the movement of a small bubble of gas within the lesion. The prepared needle was attached to an aspirating syringe of the Luer Lok type, Vaseline applied
to those areas most likely to allow of back-entry of air, and the dead space within the lumen of the needle and syringe filled with de-gassed sterile saline. The needle was introduced in a “boring” manner to the area of discolouration and aspiration performed (Fig. 4). Initial aspiration produced a small amount of yellow serous fluid and, in addition, a small bubble of gas. The syringe was removed from the mouth, the needle removed, and
376
Australian Dental Journal, October, 1977
the aspirated contents sealed within the syringe with molten wax (Fig. 5). Following the removal of the needle there was a copious flow of fluid from the defect. This fluid appeared t o be escaping under pressure. An opening made in the buccal bone revealed the residual contents of the cavity to be thin blood stained fluid. Traversing the central portion of the bone cavity was the inferior dental neurovascular bundle (Fig. 6) with branches to the apical regions of the related teeth. Lining to the cavity was not apparent and curettage produced only fragments of friable tissue. The wound was closed and normal postoperative healing was observed. The excised bone and curetted elements were submitted for histological examination. No cystic lining to the cavity could be demonstrated. The excised bone wall shows a thinned cortical bone margin with a lining of loosely arranged connective tissue within which are numerous capillaries (Fig. 7A, B). No signs of inflammation are apparent. The operative and histological findings confirmed the provisional diagnosis of traumatic bone cyst. The patient was last seen in 1972 when clinical and radiographic examination showed restoration of normal contour and bone structure in the area.* Discussion
The incidence of the traumatic bone cyst affecting the mandible is not known. However, since the introduction of routine panoramic radiographic screening of patients, it has become apparent that the lesion has a more common occurrence than thought previously3. I have had personal experience of 13 cases, one detected in the symphyseal region, the others being located in the premolar-molar area. All were found in patients during their second decade. Reviews of the literature43 indicate that of reported cases the large majority have been detected in the younger age groups, a mean age at detection being given as 19.72 years. However, the age
*Courtesy of D. R. Booth, Senior Lecturer in Oral Pathology, The University of Western Australia.
*Morris C R Steed D L and Jacoby J J-Traumatic bonk cyst; J . O h hi;.,28:3, 188-'195. (Mar.) 1970. Gardner A. F.. Stoller, S. M., and Steig, J. M.-A stud 'of the traumatic bone cyst of the jaws. J. Canad. D. 28:3 151-166 (Mar.) 1962. 'Huebne; G. R., and Turlington, E. G.-So-called traumatic (haanorrhagic) bone c sts of the jaws. Review of the literature and re ort o l t w o unusual cases. Oral Surg., Oral Med., and &a1 Path., 31:3. 354-365 (Mar.) 1971.
range was stated as being between 2.5 to 60 years. The lesion affects males more often than females, 83 per cent of cases being located within the body of the mandible. Two lesions having similar characteristics have been reported as occurring within the maxilla. The lesions have generally been asymptomatic, however, 25 per cent exhibited expansion, predominantly buccal5.6. Other symptoms recorded have included pain, intra-oral discharge associated with secondary infection and paraesthesias. The contents, when recorded, have been noted as being fluid of a sero-sanguineous nature which has been reported to completely or partially fill the bony defect. Some cavities have been recorded as being empty or containing a gas6,7. It has been suggested that the age of the lesion has a bearing upon the contents, those lesions of longer standing being more likely to contain a gas. It has also been stated that ultimately the lesional cavity contains air7. A suggestion has also been made that those lesions having an expansile tendency are more likely to contain gad.
To date few cases affecting the mandible have been associated with a fracture, four having been reported7. A recent case encountered at the Queen Elizabeth Hospital showed coincidental fracture of the body of the mandible related to a preexistant traumatic bone cyst. This fracture was of a traumatic nature rather than of the true pathological type, and the subsequent course of the case will be reported at a later dates. Whilst many reports of spontaneous healing of such lesions have been made, it is generally accepted that surgical intervention is necessary in order that a definitive diagnosis be determined. It has also been suggested that the non-expansile lesion is more likely to undergo spontaneous regression than that lesion exhibiting expansions. Simple surgical intervention is inevitably followed by complete bony healing with the restoration of the normal structure of the region. Although the aetiology of the lesion is still undetermined it would appear that the theory of unresolved intra-medullary haemorrhage is the most probable of those proposed to date. Extension of the lesion has been attributed to the occurrence of intermittent small capillary haemorrhages within the lining of the cavity leading to periodic variations in osmotic pressure increases of which Fordyce, G . L.-Haemorrhagic cysts of the mandible. Brit. J. Oral Sur 2:2, 80-85 (Nov.) 1964. Sieverink, N. P. J. The simple bone cyst. Tandheelkundige Monografieen. Leiden, Stafleu and Tholan, B. V., 1974. 8 Speculand, B.-Personal communication, 1976. 0
7
k-
377
Australian Dental Journal, October, 1977 result in a slow progression in the size of the lesions. In contra-distinction to the lesion found in the mandible, that lesion of the long bones, most commonly the humerus, is associated with fracture of the involved bone in approximately 65 per cent of casedo. This true unicameral, or solitary bone cyst also presents greater problems from the viewpoint of treatment than the lesion of the mandible. Additional features related to the occasional partitioning of the principal lesion and the histology also show differences to the lesion of the mandiblell. Unfortunately, efforts made to determine the nature of the gas apparently obtained from the reported lesion were in vain. Consultation with related specialist scientific investigators was made with such a view. However, the difficulties pre-
0
Toller. P. A.-Radioactive
isotone and other investina-
and -Joint Sura., - . 36A. 2. 2( ( A p 2 . - 1954. L.-The solitary bone cyst. In, Tumours and tumorous conditions of the bones and joints. London, Henry Kimpton, 1961 (pp. 63-75).
11 Jaffe.
sented by the proposed removal of the gas bubble and subsequent analysis could not, at that time, be solved. Further efforts to obtain gaseous samples from such lesions of the mandible should be encouraged. Determination of the nature of any gas may contribute to an understanding of the aetiology of the abnormality. Summary
A case is reported of traumatic cyst lying in the molar region of the mandible. It extended to the inferior border of the mandible and extended the buccal alveolar bone. The cystic cavity contained the inferior neuro-vascular bundle yellow serous fluid, and a small amount of gas. The wall of the cavity was lined with loosely arranged connective tissue with numerous capillaries. Healing was uneventful and clinical and radiographic examinations revealed restoration of bone structure and normal contours. Department of Oral Pathology and Oral Surgery, The University of Adelaide, North Terrace, Adelaide, S.A., 5000.
Australian Dental Journal, October, 1977 Volume 22, No. 5
The traumatic bone cyst
John R. Herd, M.D.Sc., L.D.S., F.R.A.C.D.S. Formerly Reader in Oral Surgery, Department of Oral Pathology and Oral Surgery, The University of Adelaide (Received for publication August, 1976)
Introduction The traumatic bone cyst affecting the mandible is a lesion that has an indeterminate aetiology. Whilst it has generally been related to the lesion usually referred t o as the unicameral bone cyst, most commonly affecting long bones, it would appear that there are certain differences in respect of mode of presentation, basic histopathology, and response to treatment that would seem to form an argument that it may be a separate entity. Certain aspects of its clinical behaviour may be related to its aetiology. The following case is reported because it appears that a gaseous component was demonstrated as being part of the contents of the lesion described. Previous suppositions in respect d the contents of these abnormalities have included references t o the possibility of the presence of gas, but to date no definite proof in support of these statements has been produced1.2. Blum T-Unusual bone cavities of the mandible: a repdrt of three cases of traumatic bone cysts. J.A.D.A., 19:2 281-301 (Feb ) 1932. 2 Whiner;. I . G.-Pronrkssive bone cavities of the mandible. A review of thesc-called traumatic bone cyst and a report of three cases. Oral Surg., Oral Med., and Oral Path., 8 : s . 903-916 (Aug.) 1955.
3
Case history
A 14-year-old, healthy Caucasian girl was referred to the Oral Surgery Clinic of the Perth Dental Hospital in March, 1969, for the investigation of an asymptomatic swelling in the region of the left mandible. This had recently been noted by the patient’s parents but no definite history related to the rate of development was available. At the initial clinical examination a slight facial asymmetry was apparent (Fig. 1). There was no other detectable oro-facial or cervical abnormality. Intra-oral examination revealed a smooth, “shelving” expansion of the buccal aspect of the mandible extending from the mesial of the first molar to the region of the unerupled third molar. The overlying mucosa was of a normal appearance, and there was no tenderness to pressure on palpation. There was no associated detectable lingual expansion. A periapical radiograph of the region showed a well-defined radiolucent area extending from the mesial of the first molar to that of the unerupted third molar (Fig. 2). This was of an even degree of radiolucency and had the appearance of a scalloping extension towards the alveolar crest between the roots of the teeth in the area. The
374
Australian Dental Journal, October, 1977
images of the periodontal spaces of these teeth were distinct from the main body of the radiolucency. Examination of lateral oblique and anteroposterior radiographs confirmed that the expansion was of a buccal nature, and showed the radiolucent
Fig. 1.-Facial
Fig. 3.-A,
asymmetry with mild expansion left mandible.
The provisional diagnosis was that of traumatic bone cyst. A decision for surgical intervention was made to confirm the provisional diagnosis. As the possibility of the presence of some gaseoiis element
Fig. 2.-Periapical radiograph left mandible. Note "scalloping" between roots of related molar teeth.
Discolouration area at distal of expanded buccal plate. B, Shift of area towards mesial
(arrows).
area to extend to the lower border of the mandible. The image of the inferior dental canal was not apparent in the region of abnormality. Vitality tests indicated that those teeth whose roots were in closest relation to the abnormal area were vital. There was no relationship of the area to the coincident impacted, unerupted second premolar.
within such lesions had been suggested it was decided to attempt the aspiration of the contents with the aim of collecting a gaseous sample. An 18 gauge needle was prepared, the bevel being removed and a saw-tooth margin prepared to enable the penetration of the overlying bone. Under general anaesthesia, a mucoperiosteal flap was reflected from the mesial of the mandibular
Australian Dental Journal, October, 1977
375
canine to the region of the third molar. The buccal expansion of the mandible in the area was apparent, but an interesting observation was the appearance of a small bluish area towards the posterior region of the clinical abnormality (Fig. 3A). The interesting observation was that, upon
Fig. X-Gas
bubble sealed within syringe (arrowed).
Fig. 4.-Aspiration needle introduced to cavity rhrough region of discolouration of buccal plate.
Fig. 7.-Buccal
bone and lining of bone cavity. A, H &
E X 40. B, H & E X 400.
Fig. 6.--Inferior neuro-vascular dental bundle traversing bone cavity (arrowed).
movement of the patient’s head, this area shifted in position (Fig. 3B). The similarity between this change and the change in position of the bubble in a spirit level was apparent. The impression was that of the movement of a small bubble of gas within the lesion. The prepared needle was attached to an aspirating syringe of the Luer Lok type, Vaseline applied
to those areas most likely to allow of back-entry of air, and the dead space within the lumen of the needle and syringe filled with de-gassed sterile saline. The needle was introduced in a “boring” manner to the area of discolouration and aspiration performed (Fig. 4). Initial aspiration produced a small amount of yellow serous fluid and, in addition, a small bubble of gas. The syringe was removed from the mouth, the needle removed, and
376
Australian Dental Journal, October, 1977
the aspirated contents sealed within the syringe with molten wax (Fig. 5). Following the removal of the needle there was a copious flow of fluid from the defect. This fluid appeared t o be escaping under pressure. An opening made in the buccal bone revealed the residual contents of the cavity to be thin blood stained fluid. Traversing the central portion of the bone cavity was the inferior dental neurovascular bundle (Fig. 6) with branches to the apical regions of the related teeth. Lining to the cavity was not apparent and curettage produced only fragments of friable tissue. The wound was closed and normal postoperative healing was observed. The excised bone and curetted elements were submitted for histological examination. No cystic lining to the cavity could be demonstrated. The excised bone wall shows a thinned cortical bone margin with a lining of loosely arranged connective tissue within which are numerous capillaries (Fig. 7A, B). No signs of inflammation are apparent. The operative and histological findings confirmed the provisional diagnosis of traumatic bone cyst. The patient was last seen in 1972 when clinical and radiographic examination showed restoration of normal contour and bone structure in the area.* Discussion
The incidence of the traumatic bone cyst affecting the mandible is not known. However, since the introduction of routine panoramic radiographic screening of patients, it has become apparent that the lesion has a more common occurrence than thought previously3. I have had personal experience of 13 cases, one detected in the symphyseal region, the others being located in the premolar-molar area. All were found in patients during their second decade. Reviews of the literature43 indicate that of reported cases the large majority have been detected in the younger age groups, a mean age at detection being given as 19.72 years. However, the age
*Courtesy of D. R. Booth, Senior Lecturer in Oral Pathology, The University of Western Australia.
*Morris C R Steed D L and Jacoby J J-Traumatic bonk cyst; J . O h hi;.,28:3, 188-'195. (Mar.) 1970. Gardner A. F.. Stoller, S. M., and Steig, J. M.-A stud 'of the traumatic bone cyst of the jaws. J. Canad. D. 28:3 151-166 (Mar.) 1962. 'Huebne; G. R., and Turlington, E. G.-So-called traumatic (haanorrhagic) bone c sts of the jaws. Review of the literature and re ort o l t w o unusual cases. Oral Surg., Oral Med., and &a1 Path., 31:3. 354-365 (Mar.) 1971.
range was stated as being between 2.5 to 60 years. The lesion affects males more often than females, 83 per cent of cases being located within the body of the mandible. Two lesions having similar characteristics have been reported as occurring within the maxilla. The lesions have generally been asymptomatic, however, 25 per cent exhibited expansion, predominantly buccal5.6. Other symptoms recorded have included pain, intra-oral discharge associated with secondary infection and paraesthesias. The contents, when recorded, have been noted as being fluid of a sero-sanguineous nature which has been reported to completely or partially fill the bony defect. Some cavities have been recorded as being empty or containing a gas6,7. It has been suggested that the age of the lesion has a bearing upon the contents, those lesions of longer standing being more likely to contain a gas. It has also been stated that ultimately the lesional cavity contains air7. A suggestion has also been made that those lesions having an expansile tendency are more likely to contain gad.
To date few cases affecting the mandible have been associated with a fracture, four having been reported7. A recent case encountered at the Queen Elizabeth Hospital showed coincidental fracture of the body of the mandible related to a preexistant traumatic bone cyst. This fracture was of a traumatic nature rather than of the true pathological type, and the subsequent course of the case will be reported at a later dates. Whilst many reports of spontaneous healing of such lesions have been made, it is generally accepted that surgical intervention is necessary in order that a definitive diagnosis be determined. It has also been suggested that the non-expansile lesion is more likely to undergo spontaneous regression than that lesion exhibiting expansions. Simple surgical intervention is inevitably followed by complete bony healing with the restoration of the normal structure of the region. Although the aetiology of the lesion is still undetermined it would appear that the theory of unresolved intra-medullary haemorrhage is the most probable of those proposed to date. Extension of the lesion has been attributed to the occurrence of intermittent small capillary haemorrhages within the lining of the cavity leading to periodic variations in osmotic pressure increases of which Fordyce, G . L.-Haemorrhagic cysts of the mandible. Brit. J. Oral Sur 2:2, 80-85 (Nov.) 1964. Sieverink, N. P. J. The simple bone cyst. Tandheelkundige Monografieen. Leiden, Stafleu and Tholan, B. V., 1974. 8 Speculand, B.-Personal communication, 1976. 0
7
k-
377
Australian Dental Journal, October, 1977 result in a slow progression in the size of the lesions. In contra-distinction to the lesion found in the mandible, that lesion of the long bones, most commonly the humerus, is associated with fracture of the involved bone in approximately 65 per cent of casedo. This true unicameral, or solitary bone cyst also presents greater problems from the viewpoint of treatment than the lesion of the mandible. Additional features related to the occasional partitioning of the principal lesion and the histology also show differences to the lesion of the mandiblell. Unfortunately, efforts made to determine the nature of the gas apparently obtained from the reported lesion were in vain. Consultation with related specialist scientific investigators was made with such a view. However, the difficulties pre-
0
Toller. P. A.-Radioactive
isotone and other investina-
and -Joint Sura., - . 36A. 2. 2( ( A p 2 . - 1954. L.-The solitary bone cyst. In, Tumours and tumorous conditions of the bones and joints. London, Henry Kimpton, 1961 (pp. 63-75).
11 Jaffe.
sented by the proposed removal of the gas bubble and subsequent analysis could not, at that time, be solved. Further efforts to obtain gaseous samples from such lesions of the mandible should be encouraged. Determination of the nature of any gas may contribute to an understanding of the aetiology of the abnormality. Summary
A case is reported of traumatic cyst lying in the molar region of the mandible. It extended to the inferior border of the mandible and extended the buccal alveolar bone. The cystic cavity contained the inferior neuro-vascular bundle yellow serous fluid, and a small amount of gas. The wall of the cavity was lined with loosely arranged connective tissue with numerous capillaries. Healing was uneventful and clinical and radiographic examinations revealed restoration of bone structure and normal contours. Department of Oral Pathology and Oral Surgery, The University of Adelaide, North Terrace, Adelaide, S.A., 5000.
