Amit Nandan Dhar Dwivedi, MD,* Richik Tripathi, MDS,†
Prashant K. Gupta, MD,‡ Suchi Tripathi, MBBS,§ and
Sunny Garg, MBBS�
Purpose: This study evaluated the role of magnetic resonance imaging (MRI) in cases of acute condylarinjury and assessed soft tissue damage such as disc displacement, capsular tear, and hemarthrosis withinthe temporomandibular joint (TMJ).
Patients and Methods: This prospective study was conducted in 15 patients who presented withunilateral or bilateral condylar fracture or contusion with a unilateral or bilateral diagnosis of TMJ sprain/strain.Patients with trauma of less than 7 days previously with a unilateral or bilateral condylar fracture or contusionwith a diagnosis of TMJ sprain/strain were included in the present study. The clinical diagnosis of TMJ sprainwas made and further classified and graded according to the severity and type of injury. On confirmation ofthe diagnosis of condylar injury, patients underwent evaluation by MRI. All patients were treated by closedreduction of the condylar fracture and intermaxillary fixation for 14 to 21 days.
Results: Of the 15 patients, 5 were children and 10 were adults. Of all 17 TMJ cases (2 bilateral, 13unilateral), 2 condylar fractures were of the high variety and 13 were of the low variety. MRI diagnosisof disc displacement was established in 8 of 17 TMJ cases. There was a significant association betweendegrees of condylar injury and the MRI diagnosis of displaced disc and hemarthrosis. However, an MRIfinding of capsular tear was not significantly associated with the degree of condylar injury.
he incidence of condylar fracture is about 29% to0% among all mandibular fractures.1 Functional treat-
ment has been advocated as an acceptable method ofmanaging condylar fractures. Surgical managementcan lead to facial nerve damage, scar formation,wound infection, and other complications. In devel-oping countries, functional treatment is the treatment
Received from the Institute of Medical Sciences, Banaras Hindu
University, Varanasi, India.
*Assistant Professor, Department of Radiodiagnosis and Imaging.
†Senior Resident, Department of Oral and Maxillofacial Surgery.
‡Professor, Department of Radiodiagnosis and Imaging, Subharti
Medical College, Meerut, India.
§Junior Resident, Department of Internal Medicine.
�Junior Resident, Department of Internal Medicine.
2829
of choice for the management of condylar fracturebecause most patients refuse surgical managementowing to its high cost. The advantage of surgicaltreatment is the accurate reduction of fractured seg-ments and the simultaneous observation of the softtissue status of the temporomandibular joint (TMJ).Endoscopic reduction and fixation of condylar frac-
Address correspondence and reprint requests to Dr Dwivedi:
Department of Radiodiagnosis and Imaging, Institute of Medical
Sciences, Banaras Hindu University, Varanasi 221005, India; e-mail:
ture is gaining a worldwide reputation, but it requiresconsiderable skill and experience. The status of thesoft tissues of the TMJ after condylar trauma is oftenignored.
Previous studies have focused primarily on the in-cidence of condylar trauma and the various methodsand results of treatment. Little attention has beengiven to quantify the intra-articular injury associatedwith mandibular trauma, particularly of the condylarprocess. Previous studies on the acute changes in theTMJ after condylar injury have involved plain radio-graphs, computerized tomographic (CT) scans, andarthroscopic examinations. Plain radiographs and CTscans provide poor details of the soft tissues, whereasarthroscopy is invasive and often predisposes patientsto possible complications.2
Currently, magnetic resonance imaging (MRI) is themost reliable diagnostic procedure for an objective,noninvasive assessment of the intracapsular soft tissuestatus and an accurate assessment of joint morphol-ogy. Few studies have attempted to characterize thedamage sustained by intracapsular soft tissues, includ-ing the disc, joint capsule, and retrodiscal tissues,after condylar fracture. The purpose of this study wasto describe the MRI findings and characterization ofsoft tissue damage such as the disc displacement,capsular tear, and hemarthrosis associated with differ-ent types of condylar fracture.
Patients and Methods
This prospective study was conducted in the de-partments of oral and maxillofacial surgery and radio-diagnosis and imaging and approved by the institu-
FIGURE 1. Orthopantomogram showing a fracture of the right
wivedi et al. MRI of TMJ After Acute Condylar Injury. J Oral M
tional review board of the hospital. The patients were
informed about the study procedure and informedconsent was obtained.
The inclusion criteria were 1) a unilateral or bilat-eral condylar fracture or condylar contusion with adiagnosis of unilateral or bilateral diagnosis of TMJsprain/strain, 2) the presence or absence of a con-comitant fracture of the mandible without significantdisplacement or dentoalveolar injuries, and 3) a his-tory of trauma of shorter than 7 days.
The clinical criteria for a TMJ diagnosis of sprain/strain included pain in the joint during palpation,function, and assisted opening; a history of recenttrauma before the onset of pain; and pain in the jointduring right, left, protruded, or retruded movement.The diagnosis of condylar fracture was made by clin-ical examination and by radiographs, which includedorthopantograms of the mandible (Fig 1), a reverseTowne view of the skull, and a CT scan of the con-dylar region. MRI scans were performed only afterclinical and plain radiographs confirmed the presenceof condylar injury.
MR images were obtained and interpreted by 2experienced radiologists who were blinded to eachother’s findings. In case of differences, a commonconsensus was taken.
Condylar injuries were classified using the classifi-cation of Spiessl and Schroll3 and further classifieddepending on the severity of injury as grade I (ab-sence of condylar fracture), grade II (type I, II, or IIIcondylar fracture), or grade III (type IV, V, or VIcondylar fracture).
After MRI, the patients’ clinical details, includingthe presence/absence of jaw deviation, interincisalopening, occlusion, and the presence/absence of any
ular condyle (white arrow) and body mandible (yellow arrow).
ac Surg 2012.
mandib
TMJ pain/noise, were recorded. All patients were
1tsd
DWIVEDI ET AL 2831
treated by closed reduction of the condyle fractureand intermaxillary fixation for 14 to 21 days. Patientswere recalled at 1-week, 3-week, 2-month, and3-month intervals, and the clinical examination andmeasurements at follow-up were compared with thepretreatment records.
IMAGING THE TMJ
A small surface coil is placed over the TMJ; thebilateral examination can be performed with coupledcoils. Images are obtained in the open- and closed-mouth positions to assess the position and reducibil-ity (or recapture) of the articular disc. This is facili-tated by placing a specialized device in the patient’smouth to keep it open and by instructing the patientto bite down on it for the closed-mouth views. Fromaxial localizing images, sagittal and coronal planes areprescribed. Imaging is performed most commonly inthese planes to document the position of the disc.Oblique sagittal and coronal images can be orientedto the condyle but are unnecessary to display internalderangements. T1-weighted sagittal images are thecornerstone of the TMJ examination: the anatomy isclearly depicted and the imaging plane is optimal for
FIGURE 2. Magnetic resonance image of a 12-year-old child(arrow).
Dwivedi et al. MRI of TMJ After Acute Condylar Injury. J Oral Maxillof
assessing the articular disc position. T2-weighted im-ages are useful for detecting degenerative periarticu-lar changes and the presence of a joint effusion. Fatsaturation or inversion recovery renders these find-ings more conspicuous. Gradient-echo techniqueshave been implemented to obtain cine-loop motionstudies. Three-dimensional volume acquisitions allowa volume of tissue to be imaged rapidly and subse-quently viewed in any plane. The use of intra-articularand intravenous gadolinium may provide utility incertain clinical instances. For instance, an inflamedsynovium or an inflamed arthropathy will avidlyenhance after the administration of intravenousgadolinium.
Three transaxial slices are obtained for orientation.This requires a 1-minute imaging time. Several sagittalslices are then produced through the TMJ with con-stant parameters: spin echo sequence multislice im-aging using a repetition time of 800 ms, an echo timeof 28 ms, a matrix of 256 � 256, a field of view of5 � 15 cm (pixel size, 0.6 � 0.6 mm), a slicehickness of 5 mm, 2 to 3 contiguous slices, 2 acqui-itions, and an imaging time of 6.8 minutes. Discisplacement was diagnosed and classified according
fracture of the condyle showing an anteriorly displaced disc
with a
ac Surg 2012.
D
2832 MRI OF TMJ AFTER ACUTE CONDYLAR INJURY
to the criteria of Drace and Enzmann.4 The degree ofdisc displacement was classified as none (normal,0° to 10°), slight (11° to 30°), mild (31° to 50°),moderate (51° to 80°), or severe (�80°).
Results
Of 15 patients, 3 were female and 12 were male.Five patients were children (age range, 5 to 11 years;mean, 9.4 years), and 10 patients were adults (agerange, 17 to 45 years; mean, 28.6 years). Applicationof the criteria resulted in a study group of 17 jointswith condylar injury (13 unilateral and 2 bilateralcondylar injuries). Five joints had grade III injury and12 joints had grade II. All 17 joints were diagnosed ashaving joint sprain/strain.
Of the 17 TMJ cases (2 bilateral, 13 unilateral), 2condylar fractures were of a high variety and 13 wereof a low variety. Four joints were classified as grade IIIinjury and 13 joints were classified as grade II injury.An MRI diagnosis of disc displacement was estab-lished in 8 of 17 TMJs. To differentiate acute discdisplacement associated with trauma from chronicpre-existing disc displacement, the disc morphology
FIGURE 3. Bright T2 signal in the superior
wivedi et al. MRI of TMJ After Acute Condylar Injury. J Oral Maxillof
and ancillary changes were examined. In acutetrauma, the disc retains its normal shape. Over time,however, the displaced disc is deformed by thicken-ing of the posterior band and a decrease in the massof the anterior band and the central thin area, leadingto a biconvex or rounded disc. For a TMJ with gradeII injury, 4 of 11 joints were characterized by thepresence of disc displacement, whereas for a TMJwith grade III injury, all 4 joints showed displaceddisc (Fig 2). Hemarthrosis was observed in 8 of the 17TMJs. For a grade II condyle injury, 4 of 13 jointsexhibited hemarthrosis, whereas for grade III all 4joints displayed hemarthrosis (Fig 3). This confirmedthe significant relation between the degrees of injuryand the MRI finding of hemarthrosis. However, anMRI finding of a capsular tear was not significantlyassociated with the degree of condylar injury. Apartfrom disc deformity, disc displacement, and joint ef-fusion, nonvisualization of the temporal posterior at-tachment was accepted as a criterion for diagnosingdisc perforation. High signal intensity in the middle ofthe articular disc was also considered a sign of discperforation.
ompartment showing hemarthrosis (arrow).
joint c
ac Surg 2012.
ttmcseoItffalS
mtootfattr
DWIVEDI ET AL 2833
Of the 17 TMJs, only 2 showed a capsular tear (Fig 4),1 with a grade II injury and the other with a grade IIIinjury (Table 1).
Discussion
Goss and Bosanquet5 arthroscopically examined 40TMJs in 20 patients with mandibular trauma. Theyfound evidence of intra-articular damage, includinghemarthrosis and shredding of the disc and joint sur-face. The more recently injured joint exhibited hem-arthrosis and hyperemia of the capsule. The hemar-throsis resolved rapidly but the shredding remained.These investigators believed that there is a relationbetween the degree of dislocation and the damage tothe disc, with an unfractured condyle having greatestintra-articular damage and a dislocated fracture havingthe greatest disc damage. In the present study, therewas a direct correlation between the severity of injuryand damage to the disc. The authors found the great-est damage to the disc and retrodiscal tissues in the
FIGURE 4. Coronal magnetic resonance image of 13-year-oldchild showing a right subcondylar fracture and a tear of the jointcapsule (arrow).
Dwivedi et al. MRI of TMJ After Acute Condylar Injury. J OralMaxillofac Surg 2012.
dislocated high condylar fracture. Disc displacement
was present in 30.7% of displaced fractures. There-fore, it is not only the degree of dislocation, but alsothe severity of injury, that determines the degree ofdamage to the disc. This may be due to the compres-sion of the disc against the condyle and fossa duringtrauma. The disc appeared to be quite resistant toperforation because the authors found only 1 case ofperforation in 15 patients, which was present in thedislocated fracture of the condyle.
Takaku et al6 evaluated 10 patients with trauma tohe TMJ region on MRI. They found that damage tohe intracapsular structure occurred more often inobile tissues, such as the joint capsule and retrodis-
al tissue, and least often to the disc and osseoustructure. A similar observation occurred in the pres-nt study. The retrodiscal tissues were injured moreften in type IV and V fractures and less often in typeI and III fractures. A high condylar fracture causeshe greatest injury to retrodiscal tissue. The authorsound only 2 cases of a capsule tear in a type IIIracture and 1 case in a type V fracture. The authorslso observed that the chances of capsular tears areower if the condyle fracture is minimally displaced.ullivan et al,7 in their study of the MRI assessment of
acute soft tissue injury, found similar results. Theyfound capsular tears in only 2 of 13 cases of injury tothe TMJ region, which was present in the displacedfracture of the condyle. The authors found hemarthro-sis in 8 of the 17 joints, which was more severe intype IV and V fractures.
Hemarthrosis alone seems to have little role in thedevelopment of postoperative complications becausethe hematoma disappears after mobilization of thecondyle.7,8 A displaced disc or injury to the disc is
ore troublesome and, when combined with hemar-hrosis, seems to have a significant role in the devel-pment of postoperative complications. As pointedut by Ferretti et al,8 ankylosis after a condylar frac-ure develops from a complex interaction of severalactors. Removal of the condyle as a vertical supportllows the fracture surface to more closely approachhe skull base, thus increasing the likelihood of aransarticular bony fusion. Similar conclusions wereeached by Choi9 who determined after evaluating 10
patients with bilateral condyle fractures on MRI thatprolonged fixation, hemarthrosis, and condylar com-minution alone did not result in ankylosis. When acondyle fracture is accompanied by the displacementor perforation of the disc, the chance of ankylosis isgreatest. The status of the soft tissue was ignored andthere was no effective method to evaluate the TMJsoft tissue at that time. In the authors’ institute, MRI isthe preferred imaging modality to assess the TMJ.However, the cost and availability of MR scanners canbe an issue when choosing a scanning modality, es-
pecially in developing countries. MRI has the distinct
axillof
2834 MRI OF TMJ AFTER ACUTE CONDYLAR INJURY
advantage of being noninvasive and clearly visualizingthe soft tissues of the TMJ. It is an integral part in themanagement of condylar fractures.10
The soft tissue changes of the TMJ can be predictedaccurately by MRI and are in direct proportion to theseverity of the condylar injury of the mandible.Among the soft tissue changes, disc displacement andhemarthrosis seem to affect the outcome of func-tional treatment. Hemarthrosis alone seems to have asmall role in the development of complications aftertreatment; it can lead to scarring within the TMJ andthus to a mild to moderate deformity of the disc.Combined with disc displacement, it has the mostdeleterious effects because it can lead to severe inter-nal derangement within the TMJ and possible ankylo-sis. Further long-term and large-scale studies areneeded to investigate the role of MRI in the manage-ment of condylar fractures and the TMJ.
References1. Bochlogyros PN: A retrospective study of 1,521 mandibular
Table 1. MRI FINDINGS ASSOCIATED WITH DISPLACED
MRI Diagnosis
High CondyleFracture
With Displacement(n � 1)
Low CondFractur
With Displac(n � 12
Disc displacementPresent 1 3Absent 0 9
Capsular tearPresent 0 2Absent 1 10
HemarthrosisPresent 1 3Absent 0 9
Disc perforationPresent 0 0Absent 1 12
Abbreviation: MRI, magnetic resonance imaging.
Dwivedi et al. MRI of TMJ After Acute Condylar Injury. J Oral M
fractures. J Oral Maxillofac Surg 43:597, 1985
2. Chuong R: Disk displacement with condylar fractures. OralSurg Oral Med Oral Pathol Oral Radiol Endod 79:404, 1995
3. Spiessl B, Schroll K, Gesichtsschädel, in: Nigst H (Hrsg) Spe-zielle Frakturen- und Luxationslehre, Bd l. Thieme, Stuttgart,New York, S1,1972
4. Drace JE, Enzmann DR: Defining the normal temporomandib-ular joint: Closed-, partially open-, and open-mouth MR imagingof asymptomatic subjects. Radiology 177:67, 1990
5. Goss AN, Bosanquet AG: The arthroscopic appearance of acutetemporomandibular joint trauma. J Oral Maxillofac Surg 48:780, 1990
6. Takaku S, Yoshida M, Sano T, et al: Magnetic resonance imagesin patients with acute traumatic injury of the temporomandib-ular joint: A preliminary report. J Craniomaxillofac Surg 24:173,1996
7. Sullivan SM, Banghart PR, Anderson Q: Magnetic resonanceimaging assessment of acute soft tissue injuries to the temporo-mandibular joint. J Oral Maxillofac Surg 53:763, 1995
8. Ferretti C, Bryant R, Becker P, et al: Temporomandibular jointmorphology following post-traumatic ankylosis in 26 patients.Int J Oral Maxillofac Surg 34:376, 2005
9. Choi BH: Magnetic resonance imaging of the temporomandib-ular joint after functional treatment of bilateral condylar frac-tures in adults. Int J Oral Maxillofac Surg 26:344, 1997
10. Gerhard S, Ennemoser T, Rudisch A, et al: Condylar injury:Magnetic resonance imaging findings of temporomandibularjoint soft-tissue changes. Int J Oral Maxillofac Surg 36:214,
