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Comparative study of two treatment methods for internal derangement of the temporomandibular joint
TEMPOROMANDIBULAR SECTION
GEORGE
JOINT
l
OCCLUSION
EDITOR A.
ZARB
uf two tre&m4?nt meth3ds for nt of the tempromandibular juint Gary C. Anderson, D.D.S., M.S.,* John K. Schulte, and-Richard J. Goodkind, D.M.D., M.S.***
D.D.S., M.S.D.,**
Clniversity of Minnesota, School of Dentistry, Minneapolis, Minn.
onfusion in the diagnosis and treatment of temporomandibular ,joint (TM J) disorders was documented by Greene.’ He sent a TMJ dysfunction questionnaire to randomly selected dentists and physicians and found widespread differences of opinion as to the etiology, sequelae, therapy, and existence of TMJ disorders. McNeil’ advocates elimination of a single etiology-single treatment concept, because careful examination of mandibular dysfunction leads to a differential diagnosis of unique disorders of the masticatory system.3-7 One such disorder is internal TMJ derangement, which includes a structural alteration in the articular components.‘““’ Annandale” in 1887 and Pringle12 in 1981 described the structural problem of internal joint derangements. Wakelyt3 described anterior displacement of the articular disk caused by trauma to the thin posterior attachment. Irelandi presented the classic description of clicking within the TMJ, including the progression from clicking to the “closed lock” state. Rickettesls and Thompson16 also described the pathophysiology of internal derangements. Direct visualization of the displaced articular disk was realized with the development of arthrography of the TM J. Norgaardt7 pioneered this radiographic technique in 1944, and Wilkes*%‘* developed the modern diagnostic application through the use of fluoroscopy. Katzberg et al.“’ thoroughly described arthrographic technique, application, and interpretation. The present study was designed to compare the results of two treatment-methods in the management of internal joint derangements with reduction. Treatment included use of (1) a flat plane occlusal splint and (2) an orthopedic mandibular repositioning splint. Flat plane occlusal splints have been traditional treatment for the neuromuscular component of masticatory disorders.“’ Mandibular repositioning splints attempt to correct the -.-_Prrarntrd :I! !hc .\cadrmy of Denturr Prosthetics. KXi *,lasistdnt Pwfrsw Occlusion Program. **.‘kstant Prtrfessor and Director, Occlusion Program. “**Proiessor. IXrector of Graduate Prosthodontics.
392
Kansas
Cite.
disorientation disk.2’
MATERIAL
of the anteriorly
AND
displaced
articular
METHODS
Twenty patients were selected from the University of Minnesota School of Dentistry TMJ and Craniofacial Pain Clinic. All patients had (1) reciprocal clicking of the TMJ, (2) elimination of reciprocal clicking by repositioning the mandible in a protrusive position, and (3) subjective and objective joint and muscle pain. Patients were randomly assigned to one of two treatment groups. Group A included 10 women with a mean age of 23.5 years. Group B included nine women and one man with a mean age of 24 years. Patients ranged from 14 to 39 years of age.
Treatment
methods
Group A patients were treated with a maxillary flat plane acrylic resin occlusal splint designed to be similar to that advocated by Ramfjord and Ash2’ (Figs. 1 and 2). Mandibular manipulation during adjustment was performed using the bilateral technique described by Dawson.22Occlusal contact objectives on the splint were (1) centric relation occlusion coincident with centric occlusion, (2) centric relation occlusal contacts on as many posterior teeth as possible, (3) posterior occlusal contacts established on a flat surface, (4) canine disclusion of posterior teeth in lateral movements, and (5) anterior disclusions of posterior teeth in protrusive movement. Patients were instructed to wear the occlusal splints 24 hours a day. Group B patients were treated with a two-phase method that included use of an orthopedic mandibular repositioning splint in combination with a mandibular stabilization splint. In the first phase, a maxillary repositioning splint was made with an 0.08 clear acrylic shell (Buffalo Dental Mfg. Co., Brooklyn, N.Y.) formed over the maxillary cast with a Buffalo Sta-Vat machine (Buffalo Dental Mfg. Co., Inc.). The shell was fitted to the maxillary arch and examined for retention and comfort, and the patient was instructed to open and close in a protrusive end-to-end anterior tooth relationship. MARCH
1985
VOLUME
53
NUMBER
3
INTERNAL
DERANGEMENT
OF TM]
Fig. 1. Articulation markings on occlusal surface of adjusted maxillary flat plane occlusal splint.
Fig. 2. Adjusted maxillary flat plane occlusal splint in place in group A patient. This treatment position must eliminate the reciprocal click of the TM J to indicate reduction of the anteriorly displaced articular disk. The functional surface of the splint was formed clinically with autopolymerizing acrylic resin. In addition to 1 mm cuspal imprints for the mandibular posterior teeth, an anterior reverse incline was formed. Contact of the anterior reverse incline with the lingual surfaces of the mandibular anterior teeth guided the mandible into the protrusive treatment position (Figs. 3 and 4). The patient was instructed to wear the splint 24 hours a day. The second phase of treatment for group B patients was initiated after 6 weeks and included stabilization of the protrusive mandibular position. Inability of the patient to approximate the posterior teeth without the maxillary splint indicated mandibular stabilization (Fig. 5). A mandibular bilateral splint was placed to maintain the treatment position of the mandible without using the cumbersome maxillary splint. A heat-cured acrylic resin overlay of the mandibular posterior teeth with a stainless steel lingual bar was made (Fig. 6). The functional THE JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 3. Lateral view of maxillary repositioning with anterior reverse incline.
splint
Fig. 4. Maxillary repositioning splint in place in group B patient.
Fig. 5. Mandible in stabilized treatment position with only anterior occlusal contacts. occlusal surface was completed clinically with autopolymerizing acrylic resin. The cuspal imprints (1 mm in depth) of the maxillary posterior teeth guided the mandible into the treatment position (Fig. 7). The patient was instructed to wear the mandibular splint during the day and the maxillary splint when sleeping. 393
ANDERSON,
SCHULTE,
AND
GOODKIND
Fig. 6. Mandibular bilateral splint with occlusal indentations
Fig. 7. Mandibular bilateral splint in place in group B patient.
Table I. Anamnestic -.-._l_.-
Table II. Clinical
Group
Improved
index No change
Exacerbated
The maxillary splint was needed during sleep because instances of intermittent closed-lock positions on awakening have been observed with use of the mandibular splint alone. Adjustments were made for both groups 1 week after insertion Subsequent appointments were scheduled every 3 weeks for the 90-day duration of the study. Treatment for both subject groups was provided by one of us (G.C.A.). ‘The Helkimo dysfunction indexa’ (HDI) was used to evaluate the results of the two treatment methods. The three separate indexes (clinical dysfunction index, anamnestic index? and occlusal index) of the HDI classify patients at specific levels of dysfunction dependent on the presenting signs and symptoms. The clinical dysfunction index evaluates the functional state of the masticatory system. This index is based on evaluation of (1) impaired range of movement of the mandible, (2) impaired function of the TMJ (clicking and locking), (3) pain on movement of the mandible, (4) pain in the TM J, and (5) pain in the masticatory muscles. The anamnestic dysfunction index analyzes interview data about a patient’s dysfunction. The occlusal index evaluates the occlusion by considering (1) the number of teeth, (2) the number of occluding teeth, (3) interferences in centric relation, and (4) interferences in excursive movements. Statistical analysis of changes in HDI levels were used to evaluate treatment responses. The clinical dysfunction and anamnestic indexes were applied before treatment and 90 days after insertion of the splints. The occlusal index was used before treatment to evaluate the tooth relationships of both groups. All evaluations were performed by another of us (J.K.S.). Fisher’s exact probability tes?” 394
Group
dysfunction
Improved
A
1
B
7
index Exacerbated
No change
7 3
2 0
was applied to analyze the results. The data were placed into 2 x 2 tables according to a response of improved, no change, or exacerbated results. To fit the 2 X 2 format, the responses were combined into (1) improved vs. not improved (included no change and exacerbated), and (2) exacerbated vs. not exacerbated (included no change and improved). The test was applied to the anamnestic and clinical dysfunction indexes as well as to the five individual components of the clinical dysfunction index. RESULTS Fifty percent of group A had mild occlusal disturbances and 50% had severe occlusal disturbances as determined by the occlusal index. Thirty percent of group B had mild occlusal disturbances and 70% had severe occlusal disturbances. Prior to treatment, all 20 subjects (groups A and B) had experienced severe subjective symptoms as determined by the anamnestic index. The two groups showed similar characteristics in the clinical dysfunction index prior to treatment. Twenty percent of both groups had moderate clinical signs and 80% had severe clinical signs as determined by the clinical dysfunction index. Statistical comparison of the treatment responses observed with the anamnestic index resulted in a positive association between mandibular repositioning treatment and improvement in the index level significant at 0.01 (Table I). The clinical dysfunction index comparison gave a positive association between mandibular repositioning treatment and improvement in the index signifcant at the 0.01 level (Table II). The flat plane occlusal splint treatment was associated with no significant MARCH
1985
VOLUME
53
NUMBER
3
INTERNAL
DERANGEMENT
OF TM]
change, positive or negative, in either the anamnestic or clinical dysfunction indexes (Tables I and II). Statistical evaluation of the mandibular mobility component of the clinical dysfunction index revealed no significant association between mandibular repositioning treatment and change in the index (Table III). Flat plane occlusal splint treatment was associated with a reduction in mandibular mobility significant at the 0.05 level (Table III). The mandibular dysfunction component (clicking, deviation on opening, or locking) produced a positive association between mandibular repositioning treatment and improvement in mandibular dysfunction significant at the 0.01 level (Table III). The functional pain component revealed no significant associations (Table III). The TM J pain component revealed a positive association between mandibular repositioning treatment and improvement significant at the 0.05 level (Table III). The muscle pain component revealed a positive association between mandibular repositioning treatment and improvement significant at the 0.01 level (Table III). Flat plane occlusal splint treatment produced no significant change, positive or negative, in the TMJ and muscle pain components of the clinical dysfunction index (Table III). The reciprocal click was not eliminated in eight of 10 subjects with flat plane occlusal splint treatment. The two subjects whose clicking was eliminated were in a closed-lock situation. The mandibular repositioning treatment eliminated reciprocal clicks in eight of 10 subjects. The two subjects whose clicking was not eliminated did not achieve stabilization of mandibular position and could still contact the posterior teeth on completion of the 90-day treatment period.
DISCUSSION Treatment responses No relationship was observed between the occlusal index and internal joint derangement with this limited sample. Prior to treatment, the two groups were well matched as to age, sex, occlusal index, anamnestic index, and clinical dysfunction index. The anamnestic index revealed a statistically significant reduction in symptoms when using the mandibular repositioning splint. It appears that patients subjectively believed that mandibular repositioning treatment was more efficient than flat plane occlusal splint treatment in spite of the greater inconvenience in using the repositioning splint. Mandibular repositioning also resulted in a significant reduction in the clinical dysfunction index. Both indexes showed a significant improvement in dysfunction subjectively and objectively. From these two indexes it also appeared that flat plane splint treatment had no effect, positive or negative, on internal joint derangement. Analysis of the five components of the clinical dysfunction index revealed some significant observations. A THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Table III. Compofients dysfunction
of the clinical
indejc
Variable/group Mandibular mobility A B Mandibular dysfunction A B Functional pain A B TMJ pain A B Muscle pain A B
Improved
No change
Exacerbated
1 1
5 9
4 0
0 7
1 3
3 0
3 5
6 4
1 1
1 6
7 3
2 1
0 7
10 3
0 0
reduction in mandibular mobility was observed with flat plane occlusal splint therapy. This may have resulted partially because of progression of the internal derangement to a nonreducible closed-lock position in two subjects and to an intermittent closed-lock position in a third subject. The actual significance of this observation is difficult to ascertain because a control group was not used. These three patients may have progressed to the closed-lock state without treatment. If there is a propensity for the flat plane occlusal splint to induce the closed-lock problem, it may result from relaxation of the hyperactive mast&tory musculature, because flat plane occlusal splints are known to reduce muscle activity.25 The relaxed musculature may no longer effectively splint the pathologic joint and may result in further condylar displacement and the closed-lock state. Mandibular repositioning treatment resulted in a significant improvement in mandibular dysfunction (clicking and locking) because the treatment was directed at elimination of the reciprocal click. The protrusive position encourages reduction of the displaced articular disk,Zl. 26-28 which produces the clicking.29 Carraro and CaffessejO reported difficulty in treating the clicking TMJ with flat plane occlusal splints. This finding was supported because eight of 10 patients treated with flat plane occlusal splints exhibited the reciprocal click after treatment. The two patients without clicking had progressed to the closed-lock state. One other patient who exhibited signs of the closed-lock position was in an intermittent locking stage and still exhibited reciprocal clicking after reduction of the closed-lock state. Significant reduction in muscle pain was associated with mandibular repositioning treatment. Correction of the pathologic disk displacement may result in a reduction in muscular splinting of the affected joint.3’ Two subjects in group B had no change in dysfunction status after orthopedic mandibular repositioning. At the 395
ANDERSON,
completion of treatment, both subjects exhibited reciprocal clicks because the displaced articular disk was not corrected. Neither subject had achieved mandibular stability because each could approximate the posterior teeth in occlusal contact. One subject experienced severe bruxism, which complicated the course of treatment and necessitated repair of the splint on two occasions. The cooperation of the second subject was suspect because four appointments were cancelled and compliance with the 24-hour regimen was unlikely. To correct the reciprocal click, the splint must be worn 24 hours a day,%?” A third subject in group B had no change in the anamnestic and dysfunction indexes. Although the reciprocal click was eliminated, position stability achieved, and muscle pain improved, an exacerbation in TMJ pain resulted. It is speculated that incomplete reduction of the displaced articular disk was the reason for the response
Experimental
design problems
The difficulties of controlling variables in a clinical study to evaluate splint therapies were discussed by Okeson et al ” In the present study, arthrographic evaluation was not considered because of the invasive character of the procedure, the unjustified radiation exposure, and economic factors. Correction of the internal joint derangement, therefore, was assumed with elimination of the reciprocal click. A control group was not used for the ethical and practical reasons discussed by Okeson et al.” The nature of the orthopedic treatment position is not presently understood. It is probably a neuromuscular position that allows later remodeling of the articular surfaces of the joint. The mechanism by which the repositioning therapy produces functional improvement has been postulated as soft tissue “healing,” disk remodeling, osseous remodeling, and reduction of muscle hyperactivity ‘- There is need for further investigation. The psychologic state of the patients was not addressed in this project. Kamfjord and Ash”’ related increased psychic tension to increased muscle tone and activity. The forces generated from the resultant parafunction may produce degeneration of the normal TMJ architecture. There is a need for future study to compare the psychologic state of internal joint derangement patients with that. of other mandibular dysfunction patients and with accepted psychologic norms. The 9O-day treatment period was short, and extended longitudinal studies are required to ascertain the lasting effectiveness of mandibular repositioning treatment. These studies must include evaluation of the various methods of rearticulating the posterior teeth after treatment, for example, occlusal adjustment, restorative dentistry, and orthodontic treatment. 396
SUMMARY
SCHULTE,
AND
GOODKIND
AND CONCLUSIONS
Orthopedic mandibular repositioning and flat plane occlusal splint therapy were compared in the treatment of 20 patients with internal TMJ derangement with reduction. The following conclusions can be drawn. 1. Mandibular repositioning treatment produces significant subjective and objective improvement in the dysfunction of patients with internal joint derangements with reduction. 2. Flat plane occlusal splint treatment produces no significant change in the dysfunction level of patients with internal joint derangements with reduction, 3. Mandibular repositioning treatment may eliminate the reciprocal click of internal joint derangement with reduction. 4. To realize improvement in dysfunction of internal joint derangement, it appears that the reciprocal click must be eliminated. 5. Mandibular repositioning treatment produces a significant improvement in muscle pain associated with internal joint derangement. We extend
thanks
to Kathleen
Keenan,
Ph.D.,
Associate
Professor,
Department of Oral Pathology and Genetics, University of Minnesota, School of Dentistry, for her assistance in statistical interpretation of the data.
REFERENCES 1
Greene.
2
opinions about the myofascial Assoc 86128, 1973. hlcNeil, C.: Craniomandibular
C.
S.:
Survey
the art. Part 11: Accepted PROXI‘HI:~ DENT 49:393,
of
current pain
professional
concepts
and
dysfunction.
.J Am
Dent
(TMJ)
diagnostic 1983.
disorders--The and treatment
J
3
Dingman, R. 0.: temporomandibular 1040
4.
Perry. H. ‘I‘.: The symptomology PRosrttbr DEN-~ 19:288, 1968.
5. 6
~Veinberg. I.. ‘4.: Temporomandibular dysfunctional prolile: A paucnt oriented approach. J PROS~HF;~ L?EN~ 32:3 12, 1974. Bell, W. E.: Orofacial Pains: Dilferential Diagnosis, ed 2.
7.
Chicago, 1979. Yearbook Bell, W. E.: Clinical Disorders.
8. 9. IO.
Diagnosis and treatment joint. Am J Orthodont
state ol modalities.
TMJ
1 ()8-,7 Yearbook
12 13.
Medical
,J
Publishers,
Structural and lunctional alteration of joint. Northwest Dent 57:287, 1978.
the
Farrar. W. B.: Characteristics of the condylar path in internal derangements of the TM J, J PROS~H~?. DENT 39:319, 1978. McCarty, W. L.: Surgery of the temporomandibular joint. 171 Solberg, W. K., and Clark, G. T., editors: ,Joint Problems: Biologic Diagnosis and 1980, Quintessence Publishing Co.. Inr.
11.
disturbance.
Medical Publishers, Inc. Management of Temporomandibular
ed I. Chicago,
Itl( Wilkes, (1. 13.: ielnporornandibular
of
of lesions of the Oral Surg 26374,
Annandale, the lower
T. jaw,
Temporomandibular Treatment. Chicago,
Displacement of the inter-articular and its treatment by operation.
1887. Pringle, J. 1-I.: Displacement treatment. Br J Surg 6:385,
of the mandibular 1918.
cartilage of Lancet 1:411. meniscus
Wakely, C. P. G.: The causation and treatment mandibular cartilage. Lancet 217:543, 1929.
MARCH
1985
VOLUME
53
and its
of displaced
NUMBER
3
INTERNAL
14. 15. 16. 17. 18.
19.
20. 21. 22.
23.
24.
25.
DERANGEMENT
OF TMJ
Ireland, V. E.: The problem of the clicking jaw. Ann Dent 11:3, 1952. Rickettes, R. M.: Laminagraphy in the diagnosis of TMJ disorders. J Am Dent Assoc 46:620, 1952. Thompson, J. R.: Concepts regarding function of the stomatognathir system. J Am Dent Assoc 48~626, 1954. Norgaard, F.: Arthrography of the mandibular joint. Acta Radio1 25~679, 1944. Wilkes, C. H.: Arthrography of the temporomandibular joint in patients with the TMJ pain-dysfunction syndrome. Minn Med 61:645, 1978. Katzberg, R. W., Anderson, Q. N., and Helms, C. A.: Arthrography. In Helms, C. A., Katzberg, R. W., and Dolwick, M. F., editors: Internal Derangements of the Temporomandibular Joint. San Francisco, 1983, Radiology Research and Educational Foundation. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W. B. Saunders Co., pp 248250. Farrar, W. B.: Diagnosis and treatment of anterior dislocation of the articular disc. NY J Dent 40~348, 1971. Dawson, P. E.: Evaluation, Diagnosis, and Treatment of Occlusal Problems. St. Louis, 1974, The C. V. Mosby Co., pp 54-60. Helkimo, M.: Studies on function and dysfunction of the masticatory system. II: Index for anamnestic and clinical dysfunction and occlusal state. Swed Dent J 67:101, 1974. Steele, R. G. D., and Torrie, G. H.: Principles and Procedures of Statistics with Special Reference to the Biological Sciences. New York, 1960, McGraw-Hill Book Co., Inc., pp 379-381. Jarabek, J. R.: An electromyographic analysis of muscular and temporomandibular joint disturbances due to imbalances in occlusion. Angle Orthod 26:170, 1956.
26.
27.
28.
29.
30. 31.
32.
33.
Farrar, W. B.: Treatments. In Farrar, W. B., and McCarty, W. L.: A Clinical Outline of Temporomandibular Joint Diagnosis and Treatment, ed 7. Montgomery, Ala., 1982, Normandie Publications. Dolwick, M. F., and Riggs, R. R.: Diagnosis and treatment of internal derangements of the temporomandibular joint. Dent Clin North Am 27:561, 1983. McNeil, C.: Nonsurgical management. In Helms, C. A.: Katzberg, R. W., and Dolwick, M. F.: Internal Derangements of the Temporomandibular Joint. San Francisco, 1983, Radiology Research and Education Foundation. Isberg-Hold, A.: Temporomandibular Joint Clicking. Stockholm, 1980, Department of Oral Radiology, Karolinska Institute, School of Dentistry. Carraro, J. J., and Caffesse, R. G.: ElTect of occlusal splints on TMJ symptomatology. J PR~STHET DENT 40:563, 1978. Bell, W. E.: Clinical Management of Temporomandibular Disorders, ed 1. Chicago, 1982, Yearbook Medical Publishers, Inc., p 91. Okeson, J., Moody, P. M., Kemper, J. T., and Calhoun, T. C.: Evaluation of occlusal splint therapy. J Craniomandib Pratt 1:48, 1983. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W.B. Saunders Co., p 62.
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DR. GARY C. ANDERSON UNIVERSITY OF MINNESOTA SCHWL OF DENTISTRY MINNEAPOLIS,
MN
55455
Development of anterior disk displacement in the temporomandibular joint: An autopsy study Gustaf Hellsing, Karolinska
L.D.S., Odont.Dr.,*
Institutet, School of Dentistry,
and Anders Holmlund, Huddinge,
T
emporomandibular joint (TM J) disk derangement has been extensively documented.‘-5 Anterior disk displacement (ADD) is thought to be either permanent (without reduction), that is, the whole disk stays in front of the condyle during all types of movement, or reversible (with reduction), that is, the disk is repositioned during condylar translation. Permanent ADD is reported to cause severe derangement of disk shape: from a healthy biconcave appearance to a biconvex lump of tissue. Frequent perforation of the posterior disk attachment is also reported to occur.6 FarraS found ADD in 25% of the entire population. Westesson’ broadened the concept of ADD to include oblique
*Associate **Assistant THE
Professor, Professor,
JOURNAL
Department Department
OF PROSTHETIC
of Stomatognathic of Oral Surgery. DENTISTRY
L.D.S.**
Sweden
Physiology.
or partial ADD (only the lateral part of the disk is anteriorly displaced). Reciprocal clicking is said to be a significant clinical sign of an ADD with reduction5 An important implication of this observation is that occlusal rehabilitation to the returned mandibular position would involve increased risk for development of disk displacement. Conventional clinical wisdom has identified centric relation (CR) as a reliable reference point for prosthodontic treatment; therefore, some degree of confusion has arisen. Furthermore, the proponents of the ADD philosophy suggest that retrodiskal tissue will become more and more stretched, to the point that repositioning of the disk at the end of translation will cease to occur and a “closed-lock” situation or permanent ADD develops. Clicking no longer occurs and mouth opening 397
GEORGE
JOINT
l
OCCLUSION
EDITOR A.
ZARB
uf two tre&m4?nt meth3ds for nt of the tempromandibular juint Gary C. Anderson, D.D.S., M.S.,* John K. Schulte, and-Richard J. Goodkind, D.M.D., M.S.***
D.D.S., M.S.D.,**
Clniversity of Minnesota, School of Dentistry, Minneapolis, Minn.
onfusion in the diagnosis and treatment of temporomandibular ,joint (TM J) disorders was documented by Greene.’ He sent a TMJ dysfunction questionnaire to randomly selected dentists and physicians and found widespread differences of opinion as to the etiology, sequelae, therapy, and existence of TMJ disorders. McNeil’ advocates elimination of a single etiology-single treatment concept, because careful examination of mandibular dysfunction leads to a differential diagnosis of unique disorders of the masticatory system.3-7 One such disorder is internal TMJ derangement, which includes a structural alteration in the articular components.‘““’ Annandale” in 1887 and Pringle12 in 1981 described the structural problem of internal joint derangements. Wakelyt3 described anterior displacement of the articular disk caused by trauma to the thin posterior attachment. Irelandi presented the classic description of clicking within the TMJ, including the progression from clicking to the “closed lock” state. Rickettesls and Thompson16 also described the pathophysiology of internal derangements. Direct visualization of the displaced articular disk was realized with the development of arthrography of the TM J. Norgaardt7 pioneered this radiographic technique in 1944, and Wilkes*%‘* developed the modern diagnostic application through the use of fluoroscopy. Katzberg et al.“’ thoroughly described arthrographic technique, application, and interpretation. The present study was designed to compare the results of two treatment-methods in the management of internal joint derangements with reduction. Treatment included use of (1) a flat plane occlusal splint and (2) an orthopedic mandibular repositioning splint. Flat plane occlusal splints have been traditional treatment for the neuromuscular component of masticatory disorders.“’ Mandibular repositioning splints attempt to correct the -.-_Prrarntrd :I! !hc .\cadrmy of Denturr Prosthetics. KXi *,lasistdnt Pwfrsw Occlusion Program. **.‘kstant Prtrfessor and Director, Occlusion Program. “**Proiessor. IXrector of Graduate Prosthodontics.
392
Kansas
Cite.
disorientation disk.2’
MATERIAL
of the anteriorly
AND
displaced
articular
METHODS
Twenty patients were selected from the University of Minnesota School of Dentistry TMJ and Craniofacial Pain Clinic. All patients had (1) reciprocal clicking of the TMJ, (2) elimination of reciprocal clicking by repositioning the mandible in a protrusive position, and (3) subjective and objective joint and muscle pain. Patients were randomly assigned to one of two treatment groups. Group A included 10 women with a mean age of 23.5 years. Group B included nine women and one man with a mean age of 24 years. Patients ranged from 14 to 39 years of age.
Treatment
methods
Group A patients were treated with a maxillary flat plane acrylic resin occlusal splint designed to be similar to that advocated by Ramfjord and Ash2’ (Figs. 1 and 2). Mandibular manipulation during adjustment was performed using the bilateral technique described by Dawson.22Occlusal contact objectives on the splint were (1) centric relation occlusion coincident with centric occlusion, (2) centric relation occlusal contacts on as many posterior teeth as possible, (3) posterior occlusal contacts established on a flat surface, (4) canine disclusion of posterior teeth in lateral movements, and (5) anterior disclusions of posterior teeth in protrusive movement. Patients were instructed to wear the occlusal splints 24 hours a day. Group B patients were treated with a two-phase method that included use of an orthopedic mandibular repositioning splint in combination with a mandibular stabilization splint. In the first phase, a maxillary repositioning splint was made with an 0.08 clear acrylic shell (Buffalo Dental Mfg. Co., Brooklyn, N.Y.) formed over the maxillary cast with a Buffalo Sta-Vat machine (Buffalo Dental Mfg. Co., Inc.). The shell was fitted to the maxillary arch and examined for retention and comfort, and the patient was instructed to open and close in a protrusive end-to-end anterior tooth relationship. MARCH
1985
VOLUME
53
NUMBER
3
INTERNAL
DERANGEMENT
OF TM]
Fig. 1. Articulation markings on occlusal surface of adjusted maxillary flat plane occlusal splint.
Fig. 2. Adjusted maxillary flat plane occlusal splint in place in group A patient. This treatment position must eliminate the reciprocal click of the TM J to indicate reduction of the anteriorly displaced articular disk. The functional surface of the splint was formed clinically with autopolymerizing acrylic resin. In addition to 1 mm cuspal imprints for the mandibular posterior teeth, an anterior reverse incline was formed. Contact of the anterior reverse incline with the lingual surfaces of the mandibular anterior teeth guided the mandible into the protrusive treatment position (Figs. 3 and 4). The patient was instructed to wear the splint 24 hours a day. The second phase of treatment for group B patients was initiated after 6 weeks and included stabilization of the protrusive mandibular position. Inability of the patient to approximate the posterior teeth without the maxillary splint indicated mandibular stabilization (Fig. 5). A mandibular bilateral splint was placed to maintain the treatment position of the mandible without using the cumbersome maxillary splint. A heat-cured acrylic resin overlay of the mandibular posterior teeth with a stainless steel lingual bar was made (Fig. 6). The functional THE JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 3. Lateral view of maxillary repositioning with anterior reverse incline.
splint
Fig. 4. Maxillary repositioning splint in place in group B patient.
Fig. 5. Mandible in stabilized treatment position with only anterior occlusal contacts. occlusal surface was completed clinically with autopolymerizing acrylic resin. The cuspal imprints (1 mm in depth) of the maxillary posterior teeth guided the mandible into the treatment position (Fig. 7). The patient was instructed to wear the mandibular splint during the day and the maxillary splint when sleeping. 393
ANDERSON,
SCHULTE,
AND
GOODKIND
Fig. 6. Mandibular bilateral splint with occlusal indentations
Fig. 7. Mandibular bilateral splint in place in group B patient.
Table I. Anamnestic -.-._l_.-
Table II. Clinical
Group
Improved
index No change
Exacerbated
The maxillary splint was needed during sleep because instances of intermittent closed-lock positions on awakening have been observed with use of the mandibular splint alone. Adjustments were made for both groups 1 week after insertion Subsequent appointments were scheduled every 3 weeks for the 90-day duration of the study. Treatment for both subject groups was provided by one of us (G.C.A.). ‘The Helkimo dysfunction indexa’ (HDI) was used to evaluate the results of the two treatment methods. The three separate indexes (clinical dysfunction index, anamnestic index? and occlusal index) of the HDI classify patients at specific levels of dysfunction dependent on the presenting signs and symptoms. The clinical dysfunction index evaluates the functional state of the masticatory system. This index is based on evaluation of (1) impaired range of movement of the mandible, (2) impaired function of the TMJ (clicking and locking), (3) pain on movement of the mandible, (4) pain in the TM J, and (5) pain in the masticatory muscles. The anamnestic dysfunction index analyzes interview data about a patient’s dysfunction. The occlusal index evaluates the occlusion by considering (1) the number of teeth, (2) the number of occluding teeth, (3) interferences in centric relation, and (4) interferences in excursive movements. Statistical analysis of changes in HDI levels were used to evaluate treatment responses. The clinical dysfunction and anamnestic indexes were applied before treatment and 90 days after insertion of the splints. The occlusal index was used before treatment to evaluate the tooth relationships of both groups. All evaluations were performed by another of us (J.K.S.). Fisher’s exact probability tes?” 394
Group
dysfunction
Improved
A
1
B
7
index Exacerbated
No change
7 3
2 0
was applied to analyze the results. The data were placed into 2 x 2 tables according to a response of improved, no change, or exacerbated results. To fit the 2 X 2 format, the responses were combined into (1) improved vs. not improved (included no change and exacerbated), and (2) exacerbated vs. not exacerbated (included no change and improved). The test was applied to the anamnestic and clinical dysfunction indexes as well as to the five individual components of the clinical dysfunction index. RESULTS Fifty percent of group A had mild occlusal disturbances and 50% had severe occlusal disturbances as determined by the occlusal index. Thirty percent of group B had mild occlusal disturbances and 70% had severe occlusal disturbances. Prior to treatment, all 20 subjects (groups A and B) had experienced severe subjective symptoms as determined by the anamnestic index. The two groups showed similar characteristics in the clinical dysfunction index prior to treatment. Twenty percent of both groups had moderate clinical signs and 80% had severe clinical signs as determined by the clinical dysfunction index. Statistical comparison of the treatment responses observed with the anamnestic index resulted in a positive association between mandibular repositioning treatment and improvement in the index level significant at 0.01 (Table I). The clinical dysfunction index comparison gave a positive association between mandibular repositioning treatment and improvement in the index signifcant at the 0.01 level (Table II). The flat plane occlusal splint treatment was associated with no significant MARCH
1985
VOLUME
53
NUMBER
3
INTERNAL
DERANGEMENT
OF TM]
change, positive or negative, in either the anamnestic or clinical dysfunction indexes (Tables I and II). Statistical evaluation of the mandibular mobility component of the clinical dysfunction index revealed no significant association between mandibular repositioning treatment and change in the index (Table III). Flat plane occlusal splint treatment was associated with a reduction in mandibular mobility significant at the 0.05 level (Table III). The mandibular dysfunction component (clicking, deviation on opening, or locking) produced a positive association between mandibular repositioning treatment and improvement in mandibular dysfunction significant at the 0.01 level (Table III). The functional pain component revealed no significant associations (Table III). The TM J pain component revealed a positive association between mandibular repositioning treatment and improvement significant at the 0.05 level (Table III). The muscle pain component revealed a positive association between mandibular repositioning treatment and improvement significant at the 0.01 level (Table III). Flat plane occlusal splint treatment produced no significant change, positive or negative, in the TMJ and muscle pain components of the clinical dysfunction index (Table III). The reciprocal click was not eliminated in eight of 10 subjects with flat plane occlusal splint treatment. The two subjects whose clicking was eliminated were in a closed-lock situation. The mandibular repositioning treatment eliminated reciprocal clicks in eight of 10 subjects. The two subjects whose clicking was not eliminated did not achieve stabilization of mandibular position and could still contact the posterior teeth on completion of the 90-day treatment period.
DISCUSSION Treatment responses No relationship was observed between the occlusal index and internal joint derangement with this limited sample. Prior to treatment, the two groups were well matched as to age, sex, occlusal index, anamnestic index, and clinical dysfunction index. The anamnestic index revealed a statistically significant reduction in symptoms when using the mandibular repositioning splint. It appears that patients subjectively believed that mandibular repositioning treatment was more efficient than flat plane occlusal splint treatment in spite of the greater inconvenience in using the repositioning splint. Mandibular repositioning also resulted in a significant reduction in the clinical dysfunction index. Both indexes showed a significant improvement in dysfunction subjectively and objectively. From these two indexes it also appeared that flat plane splint treatment had no effect, positive or negative, on internal joint derangement. Analysis of the five components of the clinical dysfunction index revealed some significant observations. A THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Table III. Compofients dysfunction
of the clinical
indejc
Variable/group Mandibular mobility A B Mandibular dysfunction A B Functional pain A B TMJ pain A B Muscle pain A B
Improved
No change
Exacerbated
1 1
5 9
4 0
0 7
1 3
3 0
3 5
6 4
1 1
1 6
7 3
2 1
0 7
10 3
0 0
reduction in mandibular mobility was observed with flat plane occlusal splint therapy. This may have resulted partially because of progression of the internal derangement to a nonreducible closed-lock position in two subjects and to an intermittent closed-lock position in a third subject. The actual significance of this observation is difficult to ascertain because a control group was not used. These three patients may have progressed to the closed-lock state without treatment. If there is a propensity for the flat plane occlusal splint to induce the closed-lock problem, it may result from relaxation of the hyperactive mast&tory musculature, because flat plane occlusal splints are known to reduce muscle activity.25 The relaxed musculature may no longer effectively splint the pathologic joint and may result in further condylar displacement and the closed-lock state. Mandibular repositioning treatment resulted in a significant improvement in mandibular dysfunction (clicking and locking) because the treatment was directed at elimination of the reciprocal click. The protrusive position encourages reduction of the displaced articular disk,Zl. 26-28 which produces the clicking.29 Carraro and CaffessejO reported difficulty in treating the clicking TMJ with flat plane occlusal splints. This finding was supported because eight of 10 patients treated with flat plane occlusal splints exhibited the reciprocal click after treatment. The two patients without clicking had progressed to the closed-lock state. One other patient who exhibited signs of the closed-lock position was in an intermittent locking stage and still exhibited reciprocal clicking after reduction of the closed-lock state. Significant reduction in muscle pain was associated with mandibular repositioning treatment. Correction of the pathologic disk displacement may result in a reduction in muscular splinting of the affected joint.3’ Two subjects in group B had no change in dysfunction status after orthopedic mandibular repositioning. At the 395
ANDERSON,
completion of treatment, both subjects exhibited reciprocal clicks because the displaced articular disk was not corrected. Neither subject had achieved mandibular stability because each could approximate the posterior teeth in occlusal contact. One subject experienced severe bruxism, which complicated the course of treatment and necessitated repair of the splint on two occasions. The cooperation of the second subject was suspect because four appointments were cancelled and compliance with the 24-hour regimen was unlikely. To correct the reciprocal click, the splint must be worn 24 hours a day,%?” A third subject in group B had no change in the anamnestic and dysfunction indexes. Although the reciprocal click was eliminated, position stability achieved, and muscle pain improved, an exacerbation in TMJ pain resulted. It is speculated that incomplete reduction of the displaced articular disk was the reason for the response
Experimental
design problems
The difficulties of controlling variables in a clinical study to evaluate splint therapies were discussed by Okeson et al ” In the present study, arthrographic evaluation was not considered because of the invasive character of the procedure, the unjustified radiation exposure, and economic factors. Correction of the internal joint derangement, therefore, was assumed with elimination of the reciprocal click. A control group was not used for the ethical and practical reasons discussed by Okeson et al.” The nature of the orthopedic treatment position is not presently understood. It is probably a neuromuscular position that allows later remodeling of the articular surfaces of the joint. The mechanism by which the repositioning therapy produces functional improvement has been postulated as soft tissue “healing,” disk remodeling, osseous remodeling, and reduction of muscle hyperactivity ‘- There is need for further investigation. The psychologic state of the patients was not addressed in this project. Kamfjord and Ash”’ related increased psychic tension to increased muscle tone and activity. The forces generated from the resultant parafunction may produce degeneration of the normal TMJ architecture. There is a need for future study to compare the psychologic state of internal joint derangement patients with that. of other mandibular dysfunction patients and with accepted psychologic norms. The 9O-day treatment period was short, and extended longitudinal studies are required to ascertain the lasting effectiveness of mandibular repositioning treatment. These studies must include evaluation of the various methods of rearticulating the posterior teeth after treatment, for example, occlusal adjustment, restorative dentistry, and orthodontic treatment. 396
SUMMARY
SCHULTE,
AND
GOODKIND
AND CONCLUSIONS
Orthopedic mandibular repositioning and flat plane occlusal splint therapy were compared in the treatment of 20 patients with internal TMJ derangement with reduction. The following conclusions can be drawn. 1. Mandibular repositioning treatment produces significant subjective and objective improvement in the dysfunction of patients with internal joint derangements with reduction. 2. Flat plane occlusal splint treatment produces no significant change in the dysfunction level of patients with internal joint derangements with reduction, 3. Mandibular repositioning treatment may eliminate the reciprocal click of internal joint derangement with reduction. 4. To realize improvement in dysfunction of internal joint derangement, it appears that the reciprocal click must be eliminated. 5. Mandibular repositioning treatment produces a significant improvement in muscle pain associated with internal joint derangement. We extend
thanks
to Kathleen
Keenan,
Ph.D.,
Associate
Professor,
Department of Oral Pathology and Genetics, University of Minnesota, School of Dentistry, for her assistance in statistical interpretation of the data.
REFERENCES 1
Greene.
2
opinions about the myofascial Assoc 86128, 1973. hlcNeil, C.: Craniomandibular
C.
S.:
Survey
the art. Part 11: Accepted PROXI‘HI:~ DENT 49:393,
of
current pain
professional
concepts
and
dysfunction.
.J Am
Dent
(TMJ)
diagnostic 1983.
disorders--The and treatment
J
3
Dingman, R. 0.: temporomandibular 1040
4.
Perry. H. ‘I‘.: The symptomology PRosrttbr DEN-~ 19:288, 1968.
5. 6
~Veinberg. I.. ‘4.: Temporomandibular dysfunctional prolile: A paucnt oriented approach. J PROS~HF;~ L?EN~ 32:3 12, 1974. Bell, W. E.: Orofacial Pains: Dilferential Diagnosis, ed 2.
7.
Chicago, 1979. Yearbook Bell, W. E.: Clinical Disorders.
8. 9. IO.
Diagnosis and treatment joint. Am J Orthodont
state ol modalities.
TMJ
1 ()8-,7 Yearbook
12 13.
Medical
,J
Publishers,
Structural and lunctional alteration of joint. Northwest Dent 57:287, 1978.
the
Farrar. W. B.: Characteristics of the condylar path in internal derangements of the TM J, J PROS~H~?. DENT 39:319, 1978. McCarty, W. L.: Surgery of the temporomandibular joint. 171 Solberg, W. K., and Clark, G. T., editors: ,Joint Problems: Biologic Diagnosis and 1980, Quintessence Publishing Co.. Inr.
11.
disturbance.
Medical Publishers, Inc. Management of Temporomandibular
ed I. Chicago,
Itl( Wilkes, (1. 13.: ielnporornandibular
of
of lesions of the Oral Surg 26374,
Annandale, the lower
T. jaw,
Temporomandibular Treatment. Chicago,
Displacement of the inter-articular and its treatment by operation.
1887. Pringle, J. 1-I.: Displacement treatment. Br J Surg 6:385,
of the mandibular 1918.
cartilage of Lancet 1:411. meniscus
Wakely, C. P. G.: The causation and treatment mandibular cartilage. Lancet 217:543, 1929.
MARCH
1985
VOLUME
53
and its
of displaced
NUMBER
3
INTERNAL
14. 15. 16. 17. 18.
19.
20. 21. 22.
23.
24.
25.
DERANGEMENT
OF TMJ
Ireland, V. E.: The problem of the clicking jaw. Ann Dent 11:3, 1952. Rickettes, R. M.: Laminagraphy in the diagnosis of TMJ disorders. J Am Dent Assoc 46:620, 1952. Thompson, J. R.: Concepts regarding function of the stomatognathir system. J Am Dent Assoc 48~626, 1954. Norgaard, F.: Arthrography of the mandibular joint. Acta Radio1 25~679, 1944. Wilkes, C. H.: Arthrography of the temporomandibular joint in patients with the TMJ pain-dysfunction syndrome. Minn Med 61:645, 1978. Katzberg, R. W., Anderson, Q. N., and Helms, C. A.: Arthrography. In Helms, C. A., Katzberg, R. W., and Dolwick, M. F., editors: Internal Derangements of the Temporomandibular Joint. San Francisco, 1983, Radiology Research and Educational Foundation. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W. B. Saunders Co., pp 248250. Farrar, W. B.: Diagnosis and treatment of anterior dislocation of the articular disc. NY J Dent 40~348, 1971. Dawson, P. E.: Evaluation, Diagnosis, and Treatment of Occlusal Problems. St. Louis, 1974, The C. V. Mosby Co., pp 54-60. Helkimo, M.: Studies on function and dysfunction of the masticatory system. II: Index for anamnestic and clinical dysfunction and occlusal state. Swed Dent J 67:101, 1974. Steele, R. G. D., and Torrie, G. H.: Principles and Procedures of Statistics with Special Reference to the Biological Sciences. New York, 1960, McGraw-Hill Book Co., Inc., pp 379-381. Jarabek, J. R.: An electromyographic analysis of muscular and temporomandibular joint disturbances due to imbalances in occlusion. Angle Orthod 26:170, 1956.
26.
27.
28.
29.
30. 31.
32.
33.
Farrar, W. B.: Treatments. In Farrar, W. B., and McCarty, W. L.: A Clinical Outline of Temporomandibular Joint Diagnosis and Treatment, ed 7. Montgomery, Ala., 1982, Normandie Publications. Dolwick, M. F., and Riggs, R. R.: Diagnosis and treatment of internal derangements of the temporomandibular joint. Dent Clin North Am 27:561, 1983. McNeil, C.: Nonsurgical management. In Helms, C. A.: Katzberg, R. W., and Dolwick, M. F.: Internal Derangements of the Temporomandibular Joint. San Francisco, 1983, Radiology Research and Education Foundation. Isberg-Hold, A.: Temporomandibular Joint Clicking. Stockholm, 1980, Department of Oral Radiology, Karolinska Institute, School of Dentistry. Carraro, J. J., and Caffesse, R. G.: ElTect of occlusal splints on TMJ symptomatology. J PR~STHET DENT 40:563, 1978. Bell, W. E.: Clinical Management of Temporomandibular Disorders, ed 1. Chicago, 1982, Yearbook Medical Publishers, Inc., p 91. Okeson, J., Moody, P. M., Kemper, J. T., and Calhoun, T. C.: Evaluation of occlusal splint therapy. J Craniomandib Pratt 1:48, 1983. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W.B. Saunders Co., p 62.
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DR. GARY C. ANDERSON UNIVERSITY OF MINNESOTA SCHWL OF DENTISTRY MINNEAPOLIS,
MN
55455
Development of anterior disk displacement in the temporomandibular joint: An autopsy study Gustaf Hellsing, Karolinska
L.D.S., Odont.Dr.,*
Institutet, School of Dentistry,
and Anders Holmlund, Huddinge,
T
emporomandibular joint (TM J) disk derangement has been extensively documented.‘-5 Anterior disk displacement (ADD) is thought to be either permanent (without reduction), that is, the whole disk stays in front of the condyle during all types of movement, or reversible (with reduction), that is, the disk is repositioned during condylar translation. Permanent ADD is reported to cause severe derangement of disk shape: from a healthy biconcave appearance to a biconvex lump of tissue. Frequent perforation of the posterior disk attachment is also reported to occur.6 FarraS found ADD in 25% of the entire population. Westesson’ broadened the concept of ADD to include oblique
*Associate **Assistant THE
Professor, Professor,
JOURNAL
Department Department
OF PROSTHETIC
of Stomatognathic of Oral Surgery. DENTISTRY
L.D.S.**
Sweden
Physiology.
or partial ADD (only the lateral part of the disk is anteriorly displaced). Reciprocal clicking is said to be a significant clinical sign of an ADD with reduction5 An important implication of this observation is that occlusal rehabilitation to the returned mandibular position would involve increased risk for development of disk displacement. Conventional clinical wisdom has identified centric relation (CR) as a reliable reference point for prosthodontic treatment; therefore, some degree of confusion has arisen. Furthermore, the proponents of the ADD philosophy suggest that retrodiskal tissue will become more and more stretched, to the point that repositioning of the disk at the end of translation will cease to occur and a “closed-lock” situation or permanent ADD develops. Clicking no longer occurs and mouth opening 397