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Diffuse sclerosing osteomyelitis of the mandible: A new concept of its etiology
Diffuse sclerosing osteomyelitis of the mandible: A new concept of its etiology J. P. R. van Merkesteyn, DDS, PhD,a R. H. Groot, DDS,a J. Bras, DDS, PhD,b R. S. McCarroll, DDS, PhD,C and D. J. Bakker, MD, PhD,d Amsterdam, The Netherlands ACADEMIC DENTISTRY,
MEDICAL
CENTRE,
UNIVERSITY
OF AMSTERDAM,
AND ACADEMIC
CENTRE
FOR
AMSTERDAM
Diffuse sclerosing osteomyelitis of the mandible is a disease of unknown etiology. The clinical and radiographic findings suggest an infectious origin, but bacteriologic and histologic findings do not support this concept. Analysis of clinical symptoms, localization of the condition, and posttreatment findings in a group of 27 patients suggest a chronic tendoperiostitis due to muscular overuse as an etiologic factor in diffuse sclerosing osteomyelitis of the mandible. This hypothesis was supported by the initial results of muscle relaxation treatment in 13 of these patients (ORAL Smc ORAL MED ORAL PATHOL 1990,70:414-9)
D iffuse sclerosingosteomyelitis (DSO) of the mandible, as reported in large series of patients by Jacobsson’and by van Merkesteyn and colleagues,2is a diseaseof unknown etiology for which the following etiologic hypotheses can be found in literature: immunologic reaction to bacterial toxins,3 infection4 endogenousbacterial infection5 and hyperactive immunologic response.6None of these hypotheses has led to a clear understanding and treatment of this disease,and management is therefore difficult. DSO often has a very protracted, chronic course, with up to lifelong duration. I+2,7 In occasional casesspontaneous regression has been reported.‘, 2 In this report the clinical symptoms, localization of the disease,and posttreatment findings in 27 patients with DSO of the mandible2 are analyzed, This analysis has led to the hypothesis that a chronic tendoperiostitis of one or more of the masseter or digastric musclesis an etiologic factor in DSO of the mandible. aDepartment of Oral and Maxillofacial Surgery, Academic Medical Centre, University of Amsterdam, and Academic Centre of Dentistry, Amsterdam. bDepartment of Pathology, Academic Medical Centre, University of Amsterdam. cDepartment of Masticatory Function, Academic Centre of Dentistry, Amsterdam. dDepartment of Surgery, Academic Medical Centre, University of Amsterdam. 7112113963
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MATERIAL
AND METHODS
In the period 1978 to 1986,27 patients (14 female, 13 male) with DSO of the mandible were seenin the Department of Oral and Maxillofacial Surgery of the Academic Medical Centre at the University of Amsterdam (Fig. 1); 16 were edentulous. The ages ranged from 10 to 72 years, with a median of 43 years and a mean of 42.5 years. In all patients the diagnosis of DSO was made on the basis of history, clinical symptoms, radiologic examination, and, in 24 of the 27 patients, histologic examination of biopsy or decortication specimen or both. Radiologic examination of all patients was done on panoramic radiographs, supplemented for 11 patients with computerized tomographic scans and for 2 1 patients with radionuclide bone scans (99mTcMDP), 19 of which were available. Of these 27 patients, the clinical, radiographic, and histopathologic findings have been reported separately.2 The localizations of the lesions were determined on the first panoramic radiograph on which the lesion was clearly visible and by superimposing tracings of the most active zoneson the radionucleide bone scans. Special attention was paid to localizations of secondary phenomena such as subperiosteal bone, external resorption of the cortex, and destruction of the temporomandibular joint (TMJ). In two patients biopsy specimenswere taken of the anterior attachments of masseter or digastric
Difuse sclerosing osteomyelitis of the mandible 415
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age
localization
muscle pain
hyperactive
stress relation
treatment
pat.
sex
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f
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15
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almost no symptoms after surg. lost to follow-up
18
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+
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+
?
no symptoms after surwry lost to follow-up lost to follow-up s,mfb,v
spontan. regression .
lost to follow-up lost to follow-up
m
.
no symptoms after surg. 7
s,mfb lost to follow-up
lost to follow-up
,
almost no symptoms after surg. lost to follow-up
Fig; 1. DSO of the mandible: Localization and follow-up after conventional treatment in 27 patients. m, Masseter muscle; f, temporalis muscle; d, digastric muscle; mfb, myofeedback; p, medial pterygoid muscle; s, stabilization splint; v, diazepam; n, mefenoxalon; *, seen last before 1985.
416
van Merkesteyn et al.
ORAL SURG ORAL MED ORAL PATHOL
October 1990
Fig. 2. DSO of the mandible: Subperiosteal bone and erosion of inferior cortex in distal part of mandibular body.
cles and an extensive CM0 examination, as reported by Hansson and coworkers,* were done for nine patients. Recurrent symptoms of DSO were treated by muscle relaxation (including instructions for soft diet and avoidance of parafunctional habits), rotation exercises,occlusal splint therapy, myofeedback, and muscle relaxant drugs (diazepam, mefenoxalon). RESULTS Clinical findings
Fig. 3. DSO of the mandible: Superposition of tracings of frontal imagesof bone scansshowing paired localizations of highest incidence of activity.
musclesor both including the muscle, periosteum, and bone. Of these 27 patients the pretreatment and posttreatment clinical symptoms were compared and analyzed. Since 1985, 19 of the 27 patients have been examined and special attention has been paid to symptoms of craniomuscular overuse (CMO). Electromyography of the masseter and the anterior temporal mus-
In 23 of the 25 patients treated with antibiotics, corticosteroids, explorations, intraoral decortications, implantation of gentamicin beads,hyperbaric oxygen, and combinations of these treatment modalities, the symptoms recurred.2 Two patients had not been treated. Since 1985, in which period 19 of the 27 patients were seen, special attention has been paid to symptoms of CMO. Of these 19 patients, before onset of the DSO two patients had pain in the region of the TMJ, one patient had recurrent tenderness of the neck and shoulder, and one patient had recurrent headaches. In 13 of these 19 patients parafunctional activities (bruxism, clenching, nail-biting, cocontraction, or inability to relax jaw musculature) were known or became apparent during follow-up (Fig. 1). In sevenpatients a relation of exacerbations and stress seemedpresent (Fig. 1). Palpation of the temporal, masseter, medial pterygoid, and digastric musclesin 16 of these 19 patients revealed tenderness in one or more of these muscles (at their first or at recall visits).
Diffuse sclerosing osteomyelitis
Volume 70 Number 4
of the mandible
417
Fig. 4. DSO of the mandible: Biopsy of area of attachment of digastric muscle. Low magnification shows reactive subperiosteal bone (rbJ,tendoperiosteum (fp), and digastric muscle (dm); within the tendoperiosteum are scattered small inflammatory cell infiltrates (il. For framed area see Fig. 5. (Hematoxylin-eosin stain.)
In the files of the patients seenbefore 1985, muscle tendernesson palpation was found in one patient and a stressrelation of the DSO was found in one patient. In nine patients electromyography of the masseter and the anterior temporal muscles was performed, consisting of a brief measurement of rest activity and of maximal bite force followed by measurement of submaximal activity at lo%, 20%,30%, 40% and 50% of the maximal voluntary contraction. The findings were variable but without a consistent physiopathologic pattern. In nine patients an extensive CM0 examination as reported by Hansson and associates8was performed. Static and dynamic resistance test results of the mandible were negative in sevenof the nine patients. In all but one of the patients the tests were performed between exacerbations. All the patients had unstable features in their occlusion. Radiographic
findings
The localizations of the lesions are shown in Fig. 1. The anterior region of the mandibular angle and posterior part of the mandibular body were involved in 25 of 27 patients. In the remaining two patients the lesion seemedto be restricted to the ventral part of the mandible. In four patients the mandible was affected from angle to angle. Homolateral formation of subperiosteal bone in the region of the mandibular angle, the posterior part of the mandibular body, or both (Fig. 2) was found on the initial panoramic radiograph in 11 patients; one (No. 12) also had a slight subperiosteal bone reaction near the contralateral angle of the mandible. In four additional casessubperiosteal bone was found on later radiographs. Deformation of the TMJ was found in five patients, on the homolateral side in four patients and on the contralateral side in one. In two additional patients deformation of the condyle on the homolatera1 side was found on later radiographs. In four patients an external erosion of the inferior border in the molar region was present (Fig. 2); such an erosion developedin one additional patient on later
radiographs. In one patient an erosion of the inferior border of the mandible was found on a radiograph before the radiologic signs of DSO appeared. Scintigraphic
findings
In Fig. 3 the tracings of the frontal images of the radionucleide bone scans are superimposed. On each side of the mandible an anterior and posterior region, which was affected most frequently, appeared. These sites were located in the region of the posterior part of the mandibular body and the paramedian region. A similar picture was found in superimposing the tracings of the left and right lateral images. Histologic
findings
Decortication specimens and transmandibular biopsiesshowed,as reported previously,* a reactive bone lesion characterized by formation of subperiosteal bone and remodeling of cortical and subcortical bone that resulted in an increase of bone volume. Inflammatory cells, if present, were found in the larger cortical resorption defects and the immediate subcortical area. These alterations were most pronounced in the distal buccal part of the mandibular body (area of attachment of the masseter muscle) and decreased in peripheral (posterior, anterior, lingual) directions. In a few casessimilar changeswere found in the anterior lingual part of the mandible (area of attachment of the digastric muscle).* In two patients biopsy specimenswere taken from the area of attachment of the digastric and masseter muscles, respectively. These specimensshowed reactive subperiosteal bone rimmed by active osteoblasts and covered by a thickened and fibrous periosteum that merged into epimysium and perimysium. In the thickened periosteum and epimysium, small collections of lymphocytes and plasma cells were found (Figs. 4 and 5). Treatment
Of the 19 patients treated since 1985, 13 received treatment based on a hypothesis of chronic tendope-
418
van Merkesteyn et al.
Fig. 5. DSO of the mandible: Biopsy of attachment of digastric muscle. Higher magnification (framed area of Fig. 4) shows small inflammatory cell infiltrates scattered in tendoperiosteum. (Hematoxylin-eosin stain.)
riostitis and thus aimed at relaxation of the musculature (Fig. 1); five patients did not need further treatment, and one patient was treated elsewhere. In 4 of the 13 patients the symptoms have disappeared. The follow-up period has varied from 11 to 24 months, with a mean of 15.8 months. In 7 of the 13 patients a reduction in frequency and intensity of symptoms hasoccurred. Thesepatients are still under treatment. The period of markedly reduced symptoms varied from 10 to 40 months, with a mean of 16.4 months. In the remaining two patients only a questionable or temporary reduction of symptomshasoccurred. DISCUSSION
DSO of the mandible is a disease that presents a rather uniform clinical and radiographic picture. An infectious origin, as reported in the literature, is suggested by clinical findings such as recurrent pain, swelling, and trismus, by radiographic findings such as localized osteolysis, and by scintigraphic findings such as an increased uptake of radiopharmacon. However, an infection does not fully explain the chronic recurrent character of the disease, the absence of pus formation, the predilection for the posterior part of the mandible, the resistance to treat-
ORAL SURC ORAL
MED ORAL PATHOL October 1990
ment, and in rare cases1-3’s spontaneousreduction or disappearance of symptoms with (even radiologically) a normalization of the bone architecture.‘, 5 Furthermore, cultures of bone specimens often produce negative results,‘~* and the histology of biopsy or decortication specimens shows reactive changes’, 2*9 with sometimes even nothing but normal bone.’ In our group of 27 patients, the absenceof a clear infectious etiology, the gradually reappearing recurrences after decortication of the mandible, the frequently observed parafunctional activities, and the relation of exacerbations to stress in several patients lead to the hypothesis that DSO of the mandible could be a reactive hyperplasia of bone caused by chronic tendoperiostitis probably due to muscular overuse. A review of the literature on this subject reveals similar mechanisms of stress reactions of the musculoskeletal system in other parts of the body.10*‘6According to Matheson and colleagues,r” periostitis in athletes may result solely from the pull of muscles at their insertion in bone. Overuse syndromes resulting in clinical, radiographic, scintigraphic, and histologic findings similar to those of DSO are reported in tibia, pubic bones, and clavicle. lo-l6 In the jaws a relation between muscle and bone pathosis has already been suggestedby Guggenheim and Cohen in 1959” in a report on external hyperostosis of the mandibular angle associated with masseteric hypertrophy. The hypothesis of DSO as a reactive hyperplasia of bone due to chronic traction periostitis is confirmed by the strong predilection for the posterior part of the mandibular body and the mandibular angle. In all patients of the seriesof Jacobssonand Hollender5 and in 25 of the patients in our series, the region of the anterior attachment of the masseter muscles was included in the process. In many cases subperiosteal bone was found in this region only. This localization is confirmed by the superposition of tracings of the bone scans,as shown in Fig. 3. The increased activity found in the cuspid-premolar region and the anterior part of the mandible correspondswith the attachment of the digastric muscles,which may be included in the process. The histologic findings in DSO, a preference for the distobuccal part of the mandible, and only focal inflammatory reactions located in the bone, periosteum, and muscle tissue support the suggestion of chronic tendoperiostitis. The results of treatment of DSO of the mandible, as reported in the literature, are poor, although in many casesextensive, often combined, treatment was used. In the series of Jacobsson,’ only 3 of the 16 patients treated were reported to be cured, although no period of follow-up is given. In the series of van Merkesteyn and coworkers,2 the symptoms recurred during follow-up in 23 of the 25 patients. In three of
Volume 70 Number 4
the patients the symptomswere markedly reduced, and in one of the patients the symptoms later disappeared spontaneously. The results of treatment based on muscle relaxation, as reported in this series of 13 patients (4 patients free of symptoms, 7 with reduced symptoms), seemto be superior to the aforementioned results; this fact suggestssome validity to this hypothesis. The rare and mild paresthesia of the lower lip in DSO of the mandible may be caused by an entrapment of the buccal nerve in the musculature, as described in casesof entrapment of the supraorbital and occipital nerves. The only laboratory abnormality in DSO, the erythrocyte sedimentation rate, may also be increased in casesof periostitis. Except for palpation, CM0 test results seem to be negative in many of the patients. These negative results could have occurred becausethe tests were performed between exacerbations in almost all patients. SUMMARY
Clinical and bacteriologic findings in our series of 27 patients did not support an infectious etiology of DSO of the mandible. Histopathologic examination revealed formation of subperiosteal bone, a remodelling of cortical bone, and an increase of subcortical bone volume (sclerosis).2 The radiographic and scintigraphic findings showedinvolvement of the region of attachment of masseter or digastric muscles or both in all cases.Finally, muscle relaxation therapy showed better results than did treatment based on an infectious etiology. Therefore it is concluded that DSO of the mandible is a reactive hyperplasia of bone resulting from chronic tendoperiostitis, possibly initiated and exacerbated by muscle overuse. It should be treated accordingly. We thank A. Vleeming, Department of Anatomy, Erasmus University, Rotterdam, for his help in preparing this report, and M. Naeye, PhD, for performing the electromyography studies. REFERENCES 1. JacobssonS. Diffuse sclerosing osteomyelitis of the mandible. Int J Oral Surg 1984;13:363-5.
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2. van Merkesteyn JPR, Groot RH, Bras J, Bakker DJ. Diffuse
sclerosing osteomyelitis of the mandible: clinical, radiographic and histopathological findings in 27 patients. J Oral Maxillofat Surg 1988;46:825-9. 3. Hoppe W, Utz W, Wulfhekel E. Zur Pathogeneseder Osteomyelitis sicca mandibulae. Dtsch Zahnlrztl Z 1969;24:10557. 4. Turlington EG. Chronic sclerosing non-suppurative osteomyelitis. Trans IVth Int Conf Oral Surg. Copenhagen: Munksgaard, 1973:120-4. 5. JacobssonS, Hollender L. Treatment and prognosis of diffuse sclerosing osteomyelitis (DSO) of the mandible. ORAL SURG ORAL MED ORAL PATHOL 1980;49:7-14.
6. Malmstrirm M, Fyhrquist F, Kosunen TU, Tasanen A. Immunological features of patients with chronic sclerosing osteomyelitis of the mandible. Int J Oral Surg 1983;12:6-13. 7. Heidsieck C. Zur Problematik der Therapie beim sogenannten Pseudo-Paget. Fortschr Kiefer Gesichtschir 1964;9:166-70. 8. Hansson TL, Honnee GLJM, Hesse JR. Craniomandibulaire dysfunctie. Alphen aan de Rijn/Brussel: Samson Stafleu, 1985:52. 9. Alling CC, Martinez MG. Comment on reactive hyperplasia of bone. ORAL SURG ORAL MED ORAL PATHOL 1975;40: 445-7. 10. Matheson GO, Clement DB, Mckenzie DC, Taunton JE, Lloyd-Smith DR, Macintyre JG. Stress fractures in athletes: a study of 320 cases.Am J Sports Med 1987;15:46-58. 11. Wilcox JR, Moniot AL, Green JP. Bone scanning in the evaluation of exercise-related stress injuries. Radiology 1977; 123:699-103. 12. Li G, Zhang S, Chen G, Chen H, Wang A. Radiographic and histologic analysis of stress fracture in rabbit tibias. Am J Sports Med 1985;13:285-94. 13. Schneider PG. Das Grazilissyndrom: Die Osteonecrosispubica posttraumatica. Zeitschr Orthop Grenzgebiete 1963;98:43-50. 14. Holder LE, Michael RH. The specific scintigraphic pattern of “shin splints in the lower leg”: concisecommunication. J Nucl Med 1984;25:865-9. 15. Michael RH, Holder LE. The soleus syndrome. A cause of media1tibia1 stress(shin splints). Am J Sports Med 1985;13:8794. 16. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg [Am] 1982;64-A:1053-8. 17. Guggenheim P, Cohen LB. External hyperostosis of the mandible associatedwith masseteric hypertrophy. Arch Otolaryngo1 1959;70:674-80. Reprint requests to:
Dr. J. P. R. van Merkesteyn Department of Oral and Maxillofacial Surgery Academic Medical Centre Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
MEDICAL
CENTRE,
UNIVERSITY
OF AMSTERDAM,
AND ACADEMIC
CENTRE
FOR
AMSTERDAM
Diffuse sclerosing osteomyelitis of the mandible is a disease of unknown etiology. The clinical and radiographic findings suggest an infectious origin, but bacteriologic and histologic findings do not support this concept. Analysis of clinical symptoms, localization of the condition, and posttreatment findings in a group of 27 patients suggest a chronic tendoperiostitis due to muscular overuse as an etiologic factor in diffuse sclerosing osteomyelitis of the mandible. This hypothesis was supported by the initial results of muscle relaxation treatment in 13 of these patients (ORAL Smc ORAL MED ORAL PATHOL 1990,70:414-9)
D iffuse sclerosingosteomyelitis (DSO) of the mandible, as reported in large series of patients by Jacobsson’and by van Merkesteyn and colleagues,2is a diseaseof unknown etiology for which the following etiologic hypotheses can be found in literature: immunologic reaction to bacterial toxins,3 infection4 endogenousbacterial infection5 and hyperactive immunologic response.6None of these hypotheses has led to a clear understanding and treatment of this disease,and management is therefore difficult. DSO often has a very protracted, chronic course, with up to lifelong duration. I+2,7 In occasional casesspontaneous regression has been reported.‘, 2 In this report the clinical symptoms, localization of the disease,and posttreatment findings in 27 patients with DSO of the mandible2 are analyzed, This analysis has led to the hypothesis that a chronic tendoperiostitis of one or more of the masseter or digastric musclesis an etiologic factor in DSO of the mandible. aDepartment of Oral and Maxillofacial Surgery, Academic Medical Centre, University of Amsterdam, and Academic Centre of Dentistry, Amsterdam. bDepartment of Pathology, Academic Medical Centre, University of Amsterdam. cDepartment of Masticatory Function, Academic Centre of Dentistry, Amsterdam. dDepartment of Surgery, Academic Medical Centre, University of Amsterdam. 7112113963
414
MATERIAL
AND METHODS
In the period 1978 to 1986,27 patients (14 female, 13 male) with DSO of the mandible were seenin the Department of Oral and Maxillofacial Surgery of the Academic Medical Centre at the University of Amsterdam (Fig. 1); 16 were edentulous. The ages ranged from 10 to 72 years, with a median of 43 years and a mean of 42.5 years. In all patients the diagnosis of DSO was made on the basis of history, clinical symptoms, radiologic examination, and, in 24 of the 27 patients, histologic examination of biopsy or decortication specimen or both. Radiologic examination of all patients was done on panoramic radiographs, supplemented for 11 patients with computerized tomographic scans and for 2 1 patients with radionuclide bone scans (99mTcMDP), 19 of which were available. Of these 27 patients, the clinical, radiographic, and histopathologic findings have been reported separately.2 The localizations of the lesions were determined on the first panoramic radiograph on which the lesion was clearly visible and by superimposing tracings of the most active zoneson the radionucleide bone scans. Special attention was paid to localizations of secondary phenomena such as subperiosteal bone, external resorption of the cortex, and destruction of the temporomandibular joint (TMJ). In two patients biopsy specimenswere taken of the anterior attachments of masseter or digastric
Difuse sclerosing osteomyelitis of the mandible 415
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muscle pain
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stress relation
treatment
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sex
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lost to follow-up lost to follow-up
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no symptoms after surg. 7
s,mfb lost to follow-up
lost to follow-up
,
almost no symptoms after surg. lost to follow-up
Fig; 1. DSO of the mandible: Localization and follow-up after conventional treatment in 27 patients. m, Masseter muscle; f, temporalis muscle; d, digastric muscle; mfb, myofeedback; p, medial pterygoid muscle; s, stabilization splint; v, diazepam; n, mefenoxalon; *, seen last before 1985.
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ORAL SURG ORAL MED ORAL PATHOL
October 1990
Fig. 2. DSO of the mandible: Subperiosteal bone and erosion of inferior cortex in distal part of mandibular body.
cles and an extensive CM0 examination, as reported by Hansson and coworkers,* were done for nine patients. Recurrent symptoms of DSO were treated by muscle relaxation (including instructions for soft diet and avoidance of parafunctional habits), rotation exercises,occlusal splint therapy, myofeedback, and muscle relaxant drugs (diazepam, mefenoxalon). RESULTS Clinical findings
Fig. 3. DSO of the mandible: Superposition of tracings of frontal imagesof bone scansshowing paired localizations of highest incidence of activity.
musclesor both including the muscle, periosteum, and bone. Of these 27 patients the pretreatment and posttreatment clinical symptoms were compared and analyzed. Since 1985, 19 of the 27 patients have been examined and special attention has been paid to symptoms of craniomuscular overuse (CMO). Electromyography of the masseter and the anterior temporal mus-
In 23 of the 25 patients treated with antibiotics, corticosteroids, explorations, intraoral decortications, implantation of gentamicin beads,hyperbaric oxygen, and combinations of these treatment modalities, the symptoms recurred.2 Two patients had not been treated. Since 1985, in which period 19 of the 27 patients were seen, special attention has been paid to symptoms of CMO. Of these 19 patients, before onset of the DSO two patients had pain in the region of the TMJ, one patient had recurrent tenderness of the neck and shoulder, and one patient had recurrent headaches. In 13 of these 19 patients parafunctional activities (bruxism, clenching, nail-biting, cocontraction, or inability to relax jaw musculature) were known or became apparent during follow-up (Fig. 1). In sevenpatients a relation of exacerbations and stress seemedpresent (Fig. 1). Palpation of the temporal, masseter, medial pterygoid, and digastric musclesin 16 of these 19 patients revealed tenderness in one or more of these muscles (at their first or at recall visits).
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417
Fig. 4. DSO of the mandible: Biopsy of area of attachment of digastric muscle. Low magnification shows reactive subperiosteal bone (rbJ,tendoperiosteum (fp), and digastric muscle (dm); within the tendoperiosteum are scattered small inflammatory cell infiltrates (il. For framed area see Fig. 5. (Hematoxylin-eosin stain.)
In the files of the patients seenbefore 1985, muscle tendernesson palpation was found in one patient and a stressrelation of the DSO was found in one patient. In nine patients electromyography of the masseter and the anterior temporal muscles was performed, consisting of a brief measurement of rest activity and of maximal bite force followed by measurement of submaximal activity at lo%, 20%,30%, 40% and 50% of the maximal voluntary contraction. The findings were variable but without a consistent physiopathologic pattern. In nine patients an extensive CM0 examination as reported by Hansson and associates8was performed. Static and dynamic resistance test results of the mandible were negative in sevenof the nine patients. In all but one of the patients the tests were performed between exacerbations. All the patients had unstable features in their occlusion. Radiographic
findings
The localizations of the lesions are shown in Fig. 1. The anterior region of the mandibular angle and posterior part of the mandibular body were involved in 25 of 27 patients. In the remaining two patients the lesion seemedto be restricted to the ventral part of the mandible. In four patients the mandible was affected from angle to angle. Homolateral formation of subperiosteal bone in the region of the mandibular angle, the posterior part of the mandibular body, or both (Fig. 2) was found on the initial panoramic radiograph in 11 patients; one (No. 12) also had a slight subperiosteal bone reaction near the contralateral angle of the mandible. In four additional casessubperiosteal bone was found on later radiographs. Deformation of the TMJ was found in five patients, on the homolateral side in four patients and on the contralateral side in one. In two additional patients deformation of the condyle on the homolatera1 side was found on later radiographs. In four patients an external erosion of the inferior border in the molar region was present (Fig. 2); such an erosion developedin one additional patient on later
radiographs. In one patient an erosion of the inferior border of the mandible was found on a radiograph before the radiologic signs of DSO appeared. Scintigraphic
findings
In Fig. 3 the tracings of the frontal images of the radionucleide bone scans are superimposed. On each side of the mandible an anterior and posterior region, which was affected most frequently, appeared. These sites were located in the region of the posterior part of the mandibular body and the paramedian region. A similar picture was found in superimposing the tracings of the left and right lateral images. Histologic
findings
Decortication specimens and transmandibular biopsiesshowed,as reported previously,* a reactive bone lesion characterized by formation of subperiosteal bone and remodeling of cortical and subcortical bone that resulted in an increase of bone volume. Inflammatory cells, if present, were found in the larger cortical resorption defects and the immediate subcortical area. These alterations were most pronounced in the distal buccal part of the mandibular body (area of attachment of the masseter muscle) and decreased in peripheral (posterior, anterior, lingual) directions. In a few casessimilar changeswere found in the anterior lingual part of the mandible (area of attachment of the digastric muscle).* In two patients biopsy specimenswere taken from the area of attachment of the digastric and masseter muscles, respectively. These specimensshowed reactive subperiosteal bone rimmed by active osteoblasts and covered by a thickened and fibrous periosteum that merged into epimysium and perimysium. In the thickened periosteum and epimysium, small collections of lymphocytes and plasma cells were found (Figs. 4 and 5). Treatment
Of the 19 patients treated since 1985, 13 received treatment based on a hypothesis of chronic tendope-
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van Merkesteyn et al.
Fig. 5. DSO of the mandible: Biopsy of attachment of digastric muscle. Higher magnification (framed area of Fig. 4) shows small inflammatory cell infiltrates scattered in tendoperiosteum. (Hematoxylin-eosin stain.)
riostitis and thus aimed at relaxation of the musculature (Fig. 1); five patients did not need further treatment, and one patient was treated elsewhere. In 4 of the 13 patients the symptoms have disappeared. The follow-up period has varied from 11 to 24 months, with a mean of 15.8 months. In 7 of the 13 patients a reduction in frequency and intensity of symptoms hasoccurred. Thesepatients are still under treatment. The period of markedly reduced symptoms varied from 10 to 40 months, with a mean of 16.4 months. In the remaining two patients only a questionable or temporary reduction of symptomshasoccurred. DISCUSSION
DSO of the mandible is a disease that presents a rather uniform clinical and radiographic picture. An infectious origin, as reported in the literature, is suggested by clinical findings such as recurrent pain, swelling, and trismus, by radiographic findings such as localized osteolysis, and by scintigraphic findings such as an increased uptake of radiopharmacon. However, an infection does not fully explain the chronic recurrent character of the disease, the absence of pus formation, the predilection for the posterior part of the mandible, the resistance to treat-
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ment, and in rare cases1-3’s spontaneousreduction or disappearance of symptoms with (even radiologically) a normalization of the bone architecture.‘, 5 Furthermore, cultures of bone specimens often produce negative results,‘~* and the histology of biopsy or decortication specimens shows reactive changes’, 2*9 with sometimes even nothing but normal bone.’ In our group of 27 patients, the absenceof a clear infectious etiology, the gradually reappearing recurrences after decortication of the mandible, the frequently observed parafunctional activities, and the relation of exacerbations to stress in several patients lead to the hypothesis that DSO of the mandible could be a reactive hyperplasia of bone caused by chronic tendoperiostitis probably due to muscular overuse. A review of the literature on this subject reveals similar mechanisms of stress reactions of the musculoskeletal system in other parts of the body.10*‘6According to Matheson and colleagues,r” periostitis in athletes may result solely from the pull of muscles at their insertion in bone. Overuse syndromes resulting in clinical, radiographic, scintigraphic, and histologic findings similar to those of DSO are reported in tibia, pubic bones, and clavicle. lo-l6 In the jaws a relation between muscle and bone pathosis has already been suggestedby Guggenheim and Cohen in 1959” in a report on external hyperostosis of the mandibular angle associated with masseteric hypertrophy. The hypothesis of DSO as a reactive hyperplasia of bone due to chronic traction periostitis is confirmed by the strong predilection for the posterior part of the mandibular body and the mandibular angle. In all patients of the seriesof Jacobssonand Hollender5 and in 25 of the patients in our series, the region of the anterior attachment of the masseter muscles was included in the process. In many cases subperiosteal bone was found in this region only. This localization is confirmed by the superposition of tracings of the bone scans,as shown in Fig. 3. The increased activity found in the cuspid-premolar region and the anterior part of the mandible correspondswith the attachment of the digastric muscles,which may be included in the process. The histologic findings in DSO, a preference for the distobuccal part of the mandible, and only focal inflammatory reactions located in the bone, periosteum, and muscle tissue support the suggestion of chronic tendoperiostitis. The results of treatment of DSO of the mandible, as reported in the literature, are poor, although in many casesextensive, often combined, treatment was used. In the series of Jacobsson,’ only 3 of the 16 patients treated were reported to be cured, although no period of follow-up is given. In the series of van Merkesteyn and coworkers,2 the symptoms recurred during follow-up in 23 of the 25 patients. In three of
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the patients the symptomswere markedly reduced, and in one of the patients the symptoms later disappeared spontaneously. The results of treatment based on muscle relaxation, as reported in this series of 13 patients (4 patients free of symptoms, 7 with reduced symptoms), seemto be superior to the aforementioned results; this fact suggestssome validity to this hypothesis. The rare and mild paresthesia of the lower lip in DSO of the mandible may be caused by an entrapment of the buccal nerve in the musculature, as described in casesof entrapment of the supraorbital and occipital nerves. The only laboratory abnormality in DSO, the erythrocyte sedimentation rate, may also be increased in casesof periostitis. Except for palpation, CM0 test results seem to be negative in many of the patients. These negative results could have occurred becausethe tests were performed between exacerbations in almost all patients. SUMMARY
Clinical and bacteriologic findings in our series of 27 patients did not support an infectious etiology of DSO of the mandible. Histopathologic examination revealed formation of subperiosteal bone, a remodelling of cortical bone, and an increase of subcortical bone volume (sclerosis).2 The radiographic and scintigraphic findings showedinvolvement of the region of attachment of masseter or digastric muscles or both in all cases.Finally, muscle relaxation therapy showed better results than did treatment based on an infectious etiology. Therefore it is concluded that DSO of the mandible is a reactive hyperplasia of bone resulting from chronic tendoperiostitis, possibly initiated and exacerbated by muscle overuse. It should be treated accordingly. We thank A. Vleeming, Department of Anatomy, Erasmus University, Rotterdam, for his help in preparing this report, and M. Naeye, PhD, for performing the electromyography studies. REFERENCES 1. JacobssonS. Diffuse sclerosing osteomyelitis of the mandible. Int J Oral Surg 1984;13:363-5.
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2. van Merkesteyn JPR, Groot RH, Bras J, Bakker DJ. Diffuse
sclerosing osteomyelitis of the mandible: clinical, radiographic and histopathological findings in 27 patients. J Oral Maxillofat Surg 1988;46:825-9. 3. Hoppe W, Utz W, Wulfhekel E. Zur Pathogeneseder Osteomyelitis sicca mandibulae. Dtsch Zahnlrztl Z 1969;24:10557. 4. Turlington EG. Chronic sclerosing non-suppurative osteomyelitis. Trans IVth Int Conf Oral Surg. Copenhagen: Munksgaard, 1973:120-4. 5. JacobssonS, Hollender L. Treatment and prognosis of diffuse sclerosing osteomyelitis (DSO) of the mandible. ORAL SURG ORAL MED ORAL PATHOL 1980;49:7-14.
6. Malmstrirm M, Fyhrquist F, Kosunen TU, Tasanen A. Immunological features of patients with chronic sclerosing osteomyelitis of the mandible. Int J Oral Surg 1983;12:6-13. 7. Heidsieck C. Zur Problematik der Therapie beim sogenannten Pseudo-Paget. Fortschr Kiefer Gesichtschir 1964;9:166-70. 8. Hansson TL, Honnee GLJM, Hesse JR. Craniomandibulaire dysfunctie. Alphen aan de Rijn/Brussel: Samson Stafleu, 1985:52. 9. Alling CC, Martinez MG. Comment on reactive hyperplasia of bone. ORAL SURG ORAL MED ORAL PATHOL 1975;40: 445-7. 10. Matheson GO, Clement DB, Mckenzie DC, Taunton JE, Lloyd-Smith DR, Macintyre JG. Stress fractures in athletes: a study of 320 cases.Am J Sports Med 1987;15:46-58. 11. Wilcox JR, Moniot AL, Green JP. Bone scanning in the evaluation of exercise-related stress injuries. Radiology 1977; 123:699-103. 12. Li G, Zhang S, Chen G, Chen H, Wang A. Radiographic and histologic analysis of stress fracture in rabbit tibias. Am J Sports Med 1985;13:285-94. 13. Schneider PG. Das Grazilissyndrom: Die Osteonecrosispubica posttraumatica. Zeitschr Orthop Grenzgebiete 1963;98:43-50. 14. Holder LE, Michael RH. The specific scintigraphic pattern of “shin splints in the lower leg”: concisecommunication. J Nucl Med 1984;25:865-9. 15. Michael RH, Holder LE. The soleus syndrome. A cause of media1tibia1 stress(shin splints). Am J Sports Med 1985;13:8794. 16. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg [Am] 1982;64-A:1053-8. 17. Guggenheim P, Cohen LB. External hyperostosis of the mandible associatedwith masseteric hypertrophy. Arch Otolaryngo1 1959;70:674-80. Reprint requests to:
Dr. J. P. R. van Merkesteyn Department of Oral and Maxillofacial Surgery Academic Medical Centre Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands