ABSTRACT: The aim of this study was to evaluate temporomandibular joints (TMJ) by magnetic resonance imaging (MRI) in patients who had undergone surgical/orthodontic or orthodontic treatment in a three-year follow-up study. Subjects consisted of 20 patients (40 TMJ), 16 females and four males (mean

age 33.7 years, range 19-53 years), with severe temporomandibular disorders (TMD) referred to the Oral and Maxillofacial Department at Oulu University Hospital due to skeletal jaw discrepancy. All patients underwent extensive surgical/orthodontic or orthodontic treatment between 1996 and 2003. Clinical stomatognathic examination and MRI examinations were performed before the surgical/orthodontic or orthodontic treatment and one year after the completion of the treatment. The average treatment time was 23 months (range 12-34 months). MRI revealed a marked decrease, especially in the number of TMJ with joint effusion after the treatment. There were only a few changes in the number of diagnosed disk dislocations before and after the treatment. In five joints with anterior disk dislocation with reduction (r-ADD), a change to anterior disk dislocation without reduction (nr-ADD) was found. In 25 of the 40 condyles, the condylar configuration was normal on MRI before the treatment and in 19 condyles one year after the treatment. TMD signs and symptoms according to the Helkimo dysfunction index showed a statistically significant decrease after the treatment.

Temporornandibular dysfunction is common in the adult population, especially in patients with skeletal discrepancies. (1,2) In previous studies of representative samples, the prevalence of temporomandibular disorders (TMD) in adult population varies between 20-59%. (2) When comparing the results of former studies concerning patients who seek surgical/orthodontic treatment, there is considerable variation between 26 and 73% in the prevalence of TMD. (1,3-5) One reason for this variation could be the criteria of how the signs and symptoms of TMD have been recorded and differences in referral patterns and patient motivation to seek treatment. (1,6) Population differences and age are also considered to be a cause behind this disparity. (7)

Magnetic resonance imaging (MRI) is a widely used method to examine TMJ due to its noninvasive nature and its excellent capacity to examine soft tissue structure of the TMJ. MRI gives accurate information of the configuration and position of the disk in both open- and closed-mouth positions. (8) In addition to position, configuration and function of the disk, the presence of soft tissue ingrowths, fibrosis and joint effusion is visible by MRI. (9,10) Changes in lateral pterygoid muscle can also be diagnosed in adjunct of MRI examination of TMJ. (11) Tomas, et al. (12) pointed out in their pictorial review article that in addition to the location and morphologic features of the disk with MRI, it is also important to evaluate thickening of an attachment of the lateral pterygoid muscle, rupture of retrodiskal layers, and effusion of the joint. These findings can serve as indirect early signs of TMD. It has been pointed out that joint effusion may relate to a pathological condition of the TMJ, such as inflammatory changes and synovitis. (13) Sanroman, et al. (14) reported that patients treated with surgical/orthodontic treatment have intra-articular effusion after bimaxillary surgery, and that most of the patients in their sample had an increased amount of joint fluid in the superior or inferior compartment immediately after surgery. However, the joint effusion disappeared in all cases by eight weeks after the operation. The bony contours and the cortical outline of the condyles can be seen on MRI, but when more accurate information concerning the osseous structures is needed, better information can be gained with computed tomography (CT), especially with three-dimensional CT. (15,8) Three-D imaging is seen as a gold standard technique for the bony structure of the TMJ. (16)

There are different views concerning the alterations of TMD after surgical/orthodontic treatment. Slight improvements in disk position, pain and joint sounds have been reported after surgical/orthodontic treatment. (17) However, there are some reports of a risk of causing TMJ signs and symptoms or progression by internal derangement of the joint. (18,19) Wolford, et al. (20) reported that patients with preexisting TMD have significantly more severe signs and symptoms after orthogathic surgery and also the pain scores on the visual analog scale (VAS) were significantly higher post surgically. Westesson, et al. (10) concluded that MRI is an excellent method to study morphologic changes of osseus fragment in association with surgical/orthodontic treatment. They reported thickening of the cortical bone and narrowing of the bone marrow space of the proximal segment of the condyle. Remodeling was associated with normal healing after surgery. Changes in the position of the mandibular condyle after surgical/orthodontic treatment have been studied using different radiological methods, but changes in the internal structure of the TMJ are recorded in only a few studies.

The purpose of this study was to investigate the structural changes in the TMJ obtained using MRI and the relationships of these findings with the clinical signs and symptoms of TMD in patients with severe skeletal malocclusion following surgical/orthodontic treatment at three-year follow-up.

Materials and Methods

The subjects were 20 patients (16 women and 4 men, mean age 33.7 years, range 19-53 years), all of whom were referred to the Oral and Maxillofacial Department at Oulu University Hospital between 1996 and 2003 due to temporomandibular disorders (TMD) and the need for correction of the malocclusion or skeletal jaw discrepancy. They all had severe signs and symptoms of TMD such as TMJ pain, difficulties in mouth opening, TMJ locking, pain on mandibular movement, and/or facial pain. Clinical stomatognathic examination and MRI examinations were performed before and one year after the completion of the treatment. A history of the signs and symptoms of TMD was recorded and clinical, stomatognathic examinations were performed by two calibrated observers. One calibrator, who was responsible for annual calibration of the observers, calibrated both observers. The same observers investigated the same patients before and after the treatment. The degree of TMD was evaluated using the anamnestic (Ai 0-II) and clinical dysfunction indices (Di 0-III) of Helkimo. (21)

Surgical treatment with combined pre- and post-surgical orthodontics was found necessary for 16 of the patients. In four patients, orthodontic treatment without surgery was sufficient. All patients were treated with fixed edgewise orthodontic appliances in both dental arches. The average surgical/orthodontic or orthodontic treatment time was 23 months (range 12-34 months). The surgical procedures performed were sagittal ramus osteotomy (SRO), Le Fort I-osteotomy, and lateral corticotomy. SRO was performed in 14 cases, ten of them with advancement (mean range 4.5-13.5 mm). The set back (5-7 mm) was done in three cases and in one case the rotation of the mandible was necessary to perform. Le Fort I osteotomy was done in three cases and a lateral corticotomy in one case. Bimaxillary surgery (Le Fort I and SRO) was performed in two patients who had laterognatia et apertognatia mandibulae and anterior open bite. (Table 1) The TMJ unloading splints or forward positioning splints were not used during the pre- or post-operative or other orthodontic treatment time.

MRI examinations were performed in a 1.5 T MRI scanner (Signa, General Electric, Milwaukee, WI) using a TMJ surface coil. The imaging protocol included sagittal T2-weighted (TR 3000 ms, TE 120 ms) and proton density weighted (TR 3000 ms, TE 14 ms) images with a field-of-view of 100 mm, 256x256 matrix and coronal T1-weighted (TR 400 ms, TE 10 ms) images with a FOV of 80 mm and 256x256 matrix. The TMJ were imaged with sagittal T2 weighted gradient echo sequences (TR 400 ms, TE 12 ms, flip angle 20, FOV 100 mm and 256x256 matrix) in mouth closed and maximally mouth open positions.

The configuration and function of the disk, effusion of the joint and bony structure, and movement of the condyle were defined by a radiologist. The changes in the disk configuration, i.e., deformation of the disk (thick, thin, flat or folded) as well as bony changes of the condyle, such as flattening of the articular surface, osteophyte, micro-cyst, subcortical sclerosis, and erosion, were recorded. The position and the function of the disk was classified as being in normal position, anterior disk dislocation with reduction (r-ADD) or anterior disk dislocation without reduction (n-ADD). The mouth opening capacity was recorded as being restricted when the condyle did not move down from the articular eminence to the height of the crest.

Chi-square analysis and Fisher's exact test were used for statistical analyses. Statistical significance was determined with p-values below 0.05.

Results

Before the treatment r-ADD was recorded in 9/40 TMJ (five in the right, four in the left joint) and nr-ADD in 13/40 joints (eight in the right, five in the left) (Table 2). After the treatment the number of joints with r-ADD showed a slight decrease from nine to five (four in the right, one in the left), while the number of nr-ADD showed the opposite tendency, increasing from 13 to 16 (nine in the right, seven in the left). Normal function of the disk was found after the treatment in one joint with r-ADD and in two joints with nr-ADD diagnosed before the treatment. Two normally functioning disks were diagnosed as having nr-ADD after the treatment. A change to nr-ADD was diagnosed in four joints with r-ADD, and one joint with nr-ADD changed to r-ADD alter the treatment. In other joints (30/40), no change in disk function was seen.

Changes in disk configuration, i.e., deformation of the disk (thick, thin, flat or folded), were found in 20/40 of the TMJ (11 in the right, nine in the left joint) before the treatment and in 26/40 after the treatment (15 in the right, 11 in the left). The difference was not statistically significant. MRI showed a marked decrease in the number of patients with joint effusion after the treatment (Figure 1, A and B). Before the treatment, 10/40 joints had effusion (five in the right, five in the left), compared to only two joints (both in the right joint) after the treatment (p = 0.025). The number of TMJ with restricted movement of the condyle was markedly increased after the treatment (Table 3). Before treatment, 27/40 of the joints were functioning normally (11 in the right, 16 in the left), but after the treatment the number was 17/40 (eight in the right, nine in the left) (p = 0.042). After treatment, condylar movements were more limited in patients who underwent surgical/orthodontic treatment than in those four patients who only received orthodontic treatment. There was a statistically significant increase in limited condylar movement after surgical/orthodontic treatment (p = 0.013). Before surgical/orthodontic treatment normal condylar movement was seen in 24/40 condyles, compared to 12/40 after the treatment. Hypermobility of the condyle was diagnosed in 3/40 condyles before the treatment, while none were diagnosed after the combined surgical/orthodontic or orthodontic treatment. In the clinical examination opening was more limited after the treatment than before (Table 4).

There was a tendency for condyles with normal morphology to be decreased after the treatment. In 15/40 condyles (ten in the right, five in the left), there were degenerative changes before the treatment, including flattening of the articular surface, osteophyte, micro-cyst, sclerosis, erosion or osteoarthrosis. The number of condyles with signs of degenerative changes increased to 21/40 after the treatment (13 in the right, eight in the left); the difference was not statistically significant (Figure 1, C and D). There was no statistically significant correlation between the diagnosed bony changes of the mandibular condyle and the changes in the signs and symptoms of TMD.

There was a statistically significant decrease in the signs and symptoms of TMD after the treatment assessed by Helkimo's anamnestic (p = 0.001) and clinical dysfunction indices (p = 0001). Anamnestically, all examined patients had severe TMD symptoms (AiII) before the treatment, while the majority, 12/20, had no (n = 6) or mild (n = 6) subjective symptoms (Ai0-Ail) after the treatment. Clinically severe dysfunctional symptoms (DiIII) were found to be predominant prior to treatment. Seven patients had mild or moderate symptoms (DiI-DiII) before the treatment and 19 patients after the treatment. Only one patient had severe symptoms after the treatment (Figure 2).

Before the treatment, eleven patients used the unloading splints and ten patients after the treatment. Five patients, who had used the unloading splint before the treatment, did not need splints after the treatment. Four patients who had not used a splint before needed splint therapy after the treatment. None of the patients received physical therapy, and the use of pain or other medication was occasional.

Discussion

According to literature, there are controversial views of the possible effects of orthodontic treatment on the function and structure of the TMJ. (22) The role of occlusion in the development of TMD and joint pathology has been emphasized in previous studies, but the relationship between TMD and different malocclusions is controversial. Raustia, et al. (15) have pointed out that occlusal discrepancy is to some degree related to signs and symptoms of TMD and that occlusal interferences together with other contributing factors are important in the etiology of TMD. In contrast, McNamara suggested that the relationship between TMD and occlusion is minor and selective. (23)

Surgical correction of dentofacial discrepancies seems to have a beneficial effect on subjective and clinical signs of TMD. It is quite common for patients who have had serious subjective TMJ symptoms before the treatment to report fewer symptoms after orthognathic surgery. This is explained as being due to improvement of occlusion or reduced emotional stress. J However, the TMD symptoms may become worse in some patients, while those who are symptom-free before surgery may develop TMD symptoms after surgical/orthodontic treatment. (4,24) Panula, et al. (1) concluded that the function of TMJ was significantly improved and the signs and symptoms of TMD reduced by orthognathic treatment. Westermark, et al. (2) also found that the severity of TMD was reduced and that fewer patients had two or more symptoms of TMD after orthognathic surgery. The findings in the present study were in this respect in accordance with previous findings of Panula, et al. (1) and Westermark, et al. (2) Onizawa, et al. (7) considered that alterations of TMJ symptoms after orthognathic surgery may not be the result of correction of the malocclusion. They consider that other factors such as changes in the function of masticatory muscles or changes in the structure of TMJ may also have a significant impact on TMD.

The configuration of the disks seemed to remain quite unchanged in the present study, even though there were more degenerative changes in the condyles after the treatment. Derangements of the condyle-disk complex also seemed to remain almost similar, with no marked change in the disk position in a vast majority of the joints. When treating severe malocclusion with conventional fixed appliances and with surgical/orthodontic treatment, it appears that the disk is seldom affected.

In the present study, MRI findings showed a marked decrease in the number of patients with joint effusion after the treatment when compared to the findings before and after the treatment. Westensson and Brooks (10) found a strong association between TMJ pain and increased joint effusion. In their MRI study, joint effusion was recorded in 7% of the TMJ with normal superior disk position, in 40% of the TMJ with

disk displacement with reduction, and in 50% of TMJ with disk displacement without reduction. Joint effusion was also diagnosed in 27% of patients with TMJ with osteoarthrosis and clinical symptoms of TMD. They reported that joint effusion, which was diagnosed in nonfunctional TMJ, was not associated with an inflammatory reaction in the joint compartment. Yano, et al. (13) has pointed out in a recent study concerning the internal derangement of the TMJ that joint effusion is related to signs and symptoms of TMD. They also found that the amount of fluid in the joint is an important factor in predicting the outcome of painful disk reduction cases, which is why even a small increase of fluid in the joint should be diagnosed. Joint effusion may also disappear after splint therapy even without reduction of the disk, and TMJ pain may decrease in the joints that showed a decrease in the amount of joint fluid. Larheim, et al. (25) investigated effusion on MRI images and its association with pain and bone marrow abnormalities. They found that patients with TMJ effusion represent a subgroup with pain and dysfunction with more severe intra-articular pathology than those with disk displacement but no other TMJ abnormalities. It has been noted that TMJ pain is related to internal derangement, osteoarthrosis, effusion, and bone marrow edema. (26)

[FIGURE 1 OMITTED]

Despite the positive changes in subjective signs and symptoms of TMD, more degenerative changes in the condyles were observed after the treatment than prior to it. However, no statistically significant correlation between condylar changes and the change in the signs and symptoms of TMD was noted. The proportion of the condyles with structural changes of the articular surfaces was clearly increased after the treatment. This may be partly caused by condylar remodeling because occlusion has been changed dramatically by the treatment. Pahkala, et al. (27) concluded that there are organic changes and structural abnormalities in the condyles before the treatment and that it is unrealistic to expect normalization of condylar form and disk-condyle integrity after treatment.

Link and Nickerson (28) stated that if internal derangements of TMJ were diagnosed after surgical/orthodontic treatment, they had probably existed prior to treatment and were not caused by the surgery. The continuing resorptive changes in condyles may partly reflect remodeling and adaptation after the intensive treatment. Scheerlink, et al. (29) reported that changes seen already before treatment, gender (female), open bite deformity, and high mandibular plane angle are features which seem to be risk factors for condylar resorption or further remodeling. Patients with severe preoperative signs and symptoms of TMD and a long surgical advancement of the lower jaw also tend to have an increased risk for condylar resorption after surgical/orthodontic treatment. (30) The increased loading of the temporomandibular joints as the result of the mandibular advancement is suggested to be one reason for resorption process of the condyles. (20) Fusilier, et al. (31) also pointed out that patients with untreated TMJ articular disk dislocation are at risk for changes in condylar morphology or condylar resorption after orthognathic surgery. However, in an experimental study, it was noted that bilateral nr-ADD retarded mandibular growth bilaterally, the extent corresponding to mandibular retrognathia in humans. (32)

[FIGURE 2 OMITTED]

The number of TMJ with restricted movement of the condyles was markedly increased after the treatment in this study. It has been speculated in previous studies that mandibular hypomobility following surgical/orthodontic treatment may be caused by either progressive change in the internal derangement or myofibrotic contracture resulting from the surgery. (32,33) Gaggl, et al. (17) also showed a significant reduction in mouth opening after orthognathic surgery.

Conclusion

The significant decrease in signs and symptoms of TMD after extensive surgical/orthodontic or orthodontic treatment is likely a consequence of better occlusal function, which in turn is related to favorable changes in muscular balance. The frequent resorptive changes in condylar form may partly reflect remodeling and adaptation after intensive treatment. A longer follow-up is needed to examine the present group in order to find out possible later recovery in TMJ structures.

Manuscript received April 24, 2007; revised manuscript received November 1,2007; accepted December 11,2007

References

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(12.) Tomas X, Pomes J, Berenguer J, Quinto L, Nicolau C, Mercader JM, Castro V: MR imaging of the temporomandibular joint dysfunction. RadioGraphics 2006; 26:765-781.

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(14.) Sanroman JF, Gonzales JM, Del Hoyo JA, Gil FM: Morphometric and morphological changes in the temporomandibular joint after orthognathic surgery: a magnetic resonance imaging and computed tomography prospective study. J Cranio-Maxillofac Surg 1997; 25:139-148.

(15.) Raustia A, Pyhtinen J, Tervonen O: Clinical and MRI Findings of the temporomandibular joint in relation to Occlusion in Young adults. J Craniomandib Pract 1995; 13(2):99-104.

(16.) Ciccarelli R, DiSalle F, Guidi G, Lavorgna G, Saglicco R, Rotondo A, Smaltino F: Three-dimensional imaging with computerized tomography. Etiologic considerations and methods for studying temporomandibular joints. Radiol Med 1998; 95(5):417-423.

(17.) Gaggl A, Schultes G, Santler G, Karcher H, Simbrunner J: Clinical and magnetic resonance findings in the temporomandibular joints of patients before and after orthognathic surgery. Br J Maxillofac Surg 1990; 37:41-45.

(18.) O'Ryan F, Epker BN: Surgical orthodontics and temporomandibular joint II. Mandibular advancement vie modified sagittal split osteotomies. Am J Orthod 1983; 83:418-427.

(19.) Sanders B, Kaminishi R, Buoncristiani R : Arthoscopic surgery for treatment of temporomandibular joint hypomobility after mandibular sagital split ostotomy. Oral Surg Oral Med Oral Pathol 1990; 69:539-541.

(20.) Wolford LM, Reiche-Fischel O, Mehra O: Changes in temperomandibular joint dysfunction after orthognathic surgery. J Oral Maxillofac Surg 2003: 61:655-660.

(21.) Helkimo M: Studies on function and dysfunction of the masticatory system It. Index for anamnestic and clinical dysfunction and occlusal state. Swed Dent J 1974; 67:101-121.

(22.) Sadowsky C, Polson AM: Temporomandibular disorders and functional occlusion after orthodontic treatment: Results of two long term studies. Am J Orthod 1984; 86: 5:386-390.

(23.) McNamara JA, Brudon WL: Orthodontics and dentofacial orthopedics. Ann Arbor, Michigan, Needham Press Inc. 2002, 519-543.

(24.) Dervis E, Tuncer E: Long-term evaluations of temporomandibular disorders in patients undergoing orthonathic surgery compared with a control group. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002; 94:554-560.

(25.) Larheim TA, Westesson PL, Sano T: MR grading of temporomandibular joint fluid: association with disk displacement categories, condyle marrow abnormalities and pain. Int J Oral Maxillofac Surg 2001; 30:104-112.

(26.) Emsoff R, Brandlmaier I, Bertram S, Rudisch A: Relative odds of temporomandibular joint pain as a function of magnetic resonance imaging findings of internal derangement, osteoarhrosis, effusion and bone marrow edema. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003; 95(4):437-445.

(27.) Pahkala R, Heino J: Effects of sagittal split ramus osteotomy on temporomandibular disorders in seventy-two patients. Acta Odontol Scand 2004; Aug 62(4):238-244.

(28.) Link JJ & Nickerson JW: Temporomandibular joint internal derangements in an orthognathic population. Int J Adult Orthod Orthognath Surg 1992; 7:161-169.

(29.) Scheerlink JPO, Stoelinga PJW, Blijdorp PA, Brounds JJA, Nijs MLL: Sagittal split advancement osteotomies stabilized with miniplates. A 2-5-year follow-up. Int J Oral Maxillofac Surg 1994; 23:127.

(30.) Saka B, Petsch I, Hingst J, Hartel J: The influence of pre- and intraoperative positioning of the condyle in the centre of articular fossa on the position of the disk in orthognathic surgery. A magnetic resonance study. Br J Oral Maxillofac Surg 2004; 42:120-126.

(31.) Fuselier JC, Wolford LM, Pitta MC, Talwar RM: Condylar changes after orhtognathic surgery with untreated TMJ internal derangement. J Oral Maxillofac Surg 1998; Suppl 4, 56; 61-62.

(32.) Storum KA, Bell WH: Hypomobility after maxillary and mandibular osteotomies. Oral Surg Oral Med Oral Pathol 1984; 57:847-51.

(33.) Moore KE, Gooris PJJ, Stoelinga PJW: The contributing role of condylar resorbtion to skeletal relapse following mandibular advancement surgery. Report of five cases. J Oral Maxillofac Surg 1991; 44:944-948.

Dr. Pertti Pirttiniemi received his D.D.S degree from the Institute of Dentistry, University of Turku, Finland in 1979 and his Ph.D. in 1992 front the University of Oulu, Finland. Since 1986, he has been a teacher at the Institute of Dentistry, University of Oulu. Currently, he is a professor in the Department of Orthodontics and Oral Development, Institute of Dentistry, University of Oulu, Finland

Dr. Aune M. Raustia received her D.D.S. degree from the Institute of Dentistry, University of Helsinki, Finland in 1974. She has been a teacher at the Institute of Dentistry, University of Oulu, since 1979. She received her Ph.D. degree from the same university in 1986. Currently, she is a professor in the Department of Prosthetic Dentistry and Stomatognathic Physiology at the Institute of Dentistry, University of Oulu, Finland.

Dr. Osmo Tervonen received his M.D. degree from the Medical Faculty, Oulu University, Finland in 1989 and his Ph.D. from the same university in 1998. He has been head of the Department of Radiology, Oulu University Hospital and professor in the Department of Radiology, Oulu University since 1999.

Dr. Jaana Rusanen received her D.D.S. degree from the Institute of Dentistry, University of Kuopio, Finland in 1993 and a specialization certificate in orthodontics in 2007 from the UNiversity of Oulu, Finland. Currently, she is a part-time orthodontist at Oulu University Hospital.

Address for correspondence:

Dr. Jaana Rusanen

Department of Oral Development

and Orthodontics

Institute of Dentistry

University of Oulu

P.O.Box 5281

SF-90220 Finland

E-mail: jaana.rusanen@oulu.fi

Table 1

Distribution of the Patients (n=20) Who Underwent
Surgical/Orthodontic Treatment

Patient   Diagnosis                      Age     Gender

1         Mandibular hypoplasia          19        F
2         (n=11)                         27        M
3         --occlusal relationship A II   46        F
4                                        21        F
5                                        38        F
6                                        35        F
7                                        28        F
8                                        35        F
9                                        25        M
10                                       42        F
11                                       23        F
12        Mandibular hyperplasia         52        F
13        (n=3)                          38        F
14        --occlusal relationship AIII   25        F
15        Posterior crossbite            35        M
16        (n=2)                          53        M
17        Deep bite and crowding         32        F
          (n=1)
18        Laterognathia mandibula        34        F
19        and apertognathia              32        F
20        (n=3)                          34        F
                                         Total

Patient   Diagnosis                      Surgical-orthodontic treatment

                                         LeFort I   SRO    Corticotomy

1         Mandibular hypoplasia                      x
2         (n=11)                                     x
3         --occlusal relationship A II               x
4                                                    x
5                                                    x
6                                                    x
7                                                    x
8
9                                                    x
10                                                   x
11                                                   x
12        Mandibular hyperplasia
13        (n=3)                                      x
14        --occlusal relationship AIII               x
15        Posterior crossbite                                   x
16        (n=2)                             x
17        Deep bite and crowding
          (n=1)
18        Laterognathia mandibula           x        x
19        and apertognathia
20        (n=3)                             x        x
                                           n=3      n=14       n=1

                                           Surgical-
                                          orthodontic
Patient   Diagnosis                        treatment

                                          Advancement
                                          or set back
                                                        Orthodontic
                                         Right   Left    treatment

1         Mandibular hypoplasia           7.5     7.0
2         (n=11)                         13.0    13.5
3         --occlusal relationship A II    8.0     8.0
4                                        11.0    11.0
5                                         7.0     5.0
6                                         4.5     6.0
7                                         6.0     7.0
8                                                            x
9                                         6.5     6.5
10                                       10.0    10.0
11                                        3.0     3.0
12        Mandibular hyperplasia                             x
13        (n=3)                           5.0     7.0
14        --occlusal relationship AIII    5.0     7.0
15        Posterior crossbite
16        (n=2)                           7.0     5.0
17        Deep bite and crowding                             x
          (n=1)
18        Laterognathia mandibula         2.0       0
19        and apertognathia                                  x
20        (n=3)                           0.0     2.0
                                                            n=4

Table 2

Position of the Disk, Configuration of the Disk, and Effusion of the
Joint in 20 Patients with Severe Skeletal Malocclusion Before and One
Year Following Treatment

                                            Orthodontic
                                             treatment
Patients   Diagnosis                           only

1          Mandibular hypoplasia
2            -occlusal relationship A II
3
4
5
6
7
8                                                x
9
10
11
12         Mandibular hyperplasia                x
13           -occlusal relationship A III
14
15         Posterior crossbite
16
17         Deep bite and crowding                x
18         Laterognatia mandibulae
19         and apertognatia                      x
20

Patients   Position of the disc

                    Before               After

           right        left       right        left

1          nr-ADD      nr-ADD      nr-ADD      normal
2          nr-ADD      normal      normal      normal
3          r-ADD       r-ADD       r-ADD       r-ADD
4          r-ADD       nr-ADD      nr-ADD      nr-ADD
5          nr-ADD      r-ADD       nr-ADD      nr-ADD
6          normal      normal      normal      nr-ADD
7          normal      normal      normal      normal
8          normal      nr-ADD      normal      nr-ADD
9          nr-ADD      normal      r-ADD       normal
10         nr-ADD      nr-ADD      nr-ADD      nr-ADD
11         nr-ADD      normal      nr-ADD      normal
12         r-ADD       normal      r-ADD       normal
13         nr-ADD      normal      nr-ADD      normal
14         normal      r-ADD       normal      normal
15         r-ADD       normal      r-ADD       normal
16         normal      normal      normal      normal
17         normal      normal      normal      normal
18         nr-ADD      nr-ADD      nr-ADD      nr-ADD
19         r-ADD       normal      nr-ADD      normal
20         normal      r-ADD       nr-ADD      nr-ADD
           normal=7    normal=11   normal=7    normal=12
           r-ADD=5     r-ADD=4     r-ADD=4     r-ADD=1
           nr-ADD=8    nr-ADD=5    nr-ADD=9    nr-ADD=7

Patients   Configuration of the disc

                 Before                  After

           right       left        right       left

1          deform      deform      deform      deform
2          normal      normal      deform      normal
3          normal      normal      deform      normal
4          normal      deform      deform      deform
5          normal      normal      normal      normal
6          deform      deform      deform      deform
7          normal      normal      normal      normal
8          deform      normal      deform      normal
9          normal      deform      normal      deform
10         deform      deform      deform      deform
11         normal      normal      deform      normal
12         deform      deform      deform      deform
13         deform      normal      deform      deform
14         deform      normal      deform      deform
15         normal      normal      normal      normal
16         normal      normal      normal      normal
17         deform      deform      deform      aerorm
18         deform      deform      deform      deform
19         deform      deform      deform      deform
20         deform      normal      deform      normal
           normal=9    normal=11   normal=5    normal=9
           deform=11   deform=9    deform=15   deform=11

Patients   Effusion of the joint

                 Before                  After

           right       left        right        left

1          no          no          yes          no
2          no          no          no           no
3          no          no          artefacata   no
4          yes         no          no           no
5          no          no          no           no
6          no          no          no           no
7          yes         yes         no           no
8          no          yes         no           no
9          no          no          no           no
10         no          no          no           no
11         yes         no          no           no
12         yes         no          yes          no
13         no          no          no           no
14         no          yes         no           no
15         no          no          no           no
16         no          no          no           no
17         no          no          no           no
18         no          yes         no           no
19         no          no          no           no
20         yes         yes         no           no
           yes=5       yes=5       yes=2        yes=0
           no=15       no=15       no=17        no=20
                                artefacta=1

Table 3

Configuration of the Condyle and Movement of the Condyle in 20 Patients
Who Underwent Surgical/Orthodontic Treatment Before and One Year
Following Treatment

Patients   Diagnosis

1          Mandibular hypoplasia
2            -occlusal relationship A II
3
4
5
6
7
8
9
10
11
12         Mandibular hyperplasia
13           -occlusal relationship A III
14
15         Posterior crossbite
16
17         Deep bite and crowding
18         Laterognatia mandibulae
19           and apertognatia
20

Patients   Movement of the condyle

           Before                  After

           right       left        right        left

1          normal      normal      limited      limited
2          limited     limited     limited      limited
3          large       normal      normal       normal
4          normal      normal      limited      limited
5          normal      normal      limited      limited
6          normal      normal      limited      limited
7          normal      normal      limited      limited
8          limited     limited     normal       normal
9          limited     normal      normal       limited
10         limited     limited     limited      limited
11         normal      normal      limited      normal
12         normal      normal      normal       normal
13         limited     normal      limited      limited
14         limited     normal      limited      limited
15         lar e       large       normal       normal
16         normal      normal      normal       normal
17         normal      normal      normal       normal
18         normal      normal      normal       normal
19         limited     normal      limited      normal
20         normal      normal      limited      limited
           normal=11   normal=16   normal=8     normal=9
           limited=7   limited=3   limited=12   limited=11
           large= 2    large=1     large=0      large=0

Patients   Configuration of the condyle

           Before                  After

           right       left        right        left

1          deform      deform      deform       deform
2          deform      normal      deform       normal
3          deform      deform      deform       deform
4          deform      deform      deform       deform
5          deform      deform      deform       deform
6          normal      normal      deform       normal
7          normal      normal      normal       normal
8          normal      normal      normal       deform
9          deform      normal      deform       deform
10         deform      deform      deform       deform
11         normal      normal      deform       normal
12         normal      normal      normal       normal
13         deform      normal      deform       normal
14         normal      normal      normal       normal
15         normal      normal      normal       normal
16         normal      normal      normal       normal
17         normal      normal      normal       normal
18         deform      normal      deform       deform
19         normal      normal      deform       normal
20         deform      normal      deform       normal
           normal=10   normal=15   normal=7     normal=12
           deform=1    deform=5    deform=13    deform=8

Table 4

Incisal Opening, Right and Left Laterotrusion, Protrusion, and IP-RP
Difference (mm) in 20 Patients with Severe Skeletal Malocclusion Before
and One Year Following Treatment

          incisal     incisal
           opening     opening
           before      after          right           right
          treatment   treatment   laterotrusion   laterotrusion
Patient     (mm)        (mm)       before (mm)     after (mm)

1            43          42             9               8
2            42          29            14               4
3            50          41             5               8
4            43          40             6               7
5            40          36            12              10
6            35          33            10              10
7            50          35            13               8
8            48          49             6               5
9            57          48            11              11
10           42          32             7               3
11           40          44            12              12
12           36          25             7               5
13           46          39            12               8
14           30          42            10              11
15           28          40             9               8
16           41          43            13              13
17           44          42             7              10
18           47          44             5               9
19           47          47            10              15
20           48          45             4               8
Mean        42,85       39,8           9,1            8,65
Max          57          49            14              15
Min          28          25             4               3

              left            left          maximal       maximal
          laterotrusion   laterotrusion   protrusion    protrusion
Patient    before (mm)     after (mm)     before (mm)   after (mm)

1              8,5              6             14            10
2              10               3              9             1
3               9               7             10             5
4              11              10             10             6
5              12               8             12             6
6              10               9              8             7
7              13              11             10             7
8               9               7              6             6
9              11              13             10             5
10              7               2             13             2
11             10              10              7             7
12              4               7              5             4
13             11               9              8             6
14              7              11              5             5
15              8              11              6             6
16             11              12              3             8
17             10              11              8             9
18              9               8              8             8
19              7               8              8             6
20              1              12              3             8
Mean          8,925           8,75           8,15           6,1
Max            13              13             14            10
Min             1               2              3             1

              IP-RP           IP-RP
           difference      difference
Patient    before (mm)     after (mm)

1              0,5              0
2               0               0
3               2               0
4               3               1
5               0               0
6               0               0
7               0               0
8               0               0
9               0               0
10              0               0
11              3               1
12              1               0
13              0               0
14             0,5              0
15              0               0
16              1               1
17             0,5              1
18             0,5              0
19              1               0
20              1               0
Mean           0,7             0,2
Max             3               1
Min             0               0