Temporomandibular joint symptoms in an orthognathic surgery population

Temporomandibular joint symptoms in an orthognathic surgery population Calix A. S. De Clercq, Johan S. V. Abeloos, Maurice Y. Mommaerts, Lucas F. Neyt

Division of Maxillo-Facial Surgery (Head: Prof. L. Neyt, MD, LDS, PhD), Department of Surgery, General Hospital St-John, Bruges, Belgium

S U M M A R Y . The records of 317 consecutive patients who underwent orthognathic surgery in the Division of Maxillo-Facial Surgery of the General Hospital St. John, Bruges, Belgium, between 1.10.90 and 1.10.92 were evaluated for pre- and postoperative temporomandibular joint (TMJ) symptoms. Only 143 patients, with a normal[low angle mandibular deficiency deformity, treated by mandibular advancement, and 53 high angle absolute mandibular retrognathism patients having bimaxiUary operations, were selected. Fewer TMJ symptoms were found postoperatively, than preoperatively in the total group (17.8% vs 26.5% p = 0.025, Mc Nemar). In the normal/low angle group, there was a decrease in TMJ symptoms after surgery from 30.0% to 14.6% (p = 0.0001, Mc Nemar). In the high angle group, however, more TMJ symptoms are seen postoperatively 26.4% versus 16.8% (p = 0.228, Mc Nemar). Possible hypothetical explanations are given.

INTRODUCTION

The purpose of the present study was to extend our investigation on 317 osteotomy patients and to evaluate this tendency, as found in our previous study (De Clercq et al., 1993), for these two specific groups; namely the no/lo angle mandibular deficiency group and the high angle mandibular deficiency group having bimaxillary operations.

Laskin et al. (1986), in a questionnaire survey of patients of oral and maxillofacial surgery training programmes, reported a mean incidence of 14% (range 0% to 75%) of TMJ symptoms before orthognathic surgery. Kerstens et al. (1989b) reported that 16.2% of 480 orthognathic surgery patients had temporomandibular joint (TMJ) symptoms before surgery. Two thirds of these symptomatic patients reported fewer or no symptoms after surgery. However, 11.5 % of the preoperatively asymptomatic patients developed TMJ symptoms after surgery. White and Dolwick (1992) reported that 49.3 % of the patients showed some degree of TMJ dysfunction preoperatively. In the patient group with no TMJ dysfunction preoperatively, 7.9 % developed a problem postoperatively. In a previous study (De Clercq et al., 1993), on 152 dysgnathia patients operated on in the division of Maxillo-Facial Surgery of the General Hospital St. John, Bruges, between 1.10.90 and 1.10.91, 19.7% had TMJ signs and symptoms (defined as disc dysfunction, muscle symptoms, or both) preoperatively and 14.4 % postoperatively. Although there was no statistical significance, the prevalence of TMJsymptoms in normal and low (no/lo) angle mandibular deficiency patients (SN/GoMe < / = 32 °) was higher in comparison with the high angle patients (26% vs 14.2%). The possibility is high, however, that TMJ symptoms in low and normal angle patients, only operated on by a mandibular advancement, will improve after surgery (83 %). There also seemed to be a considerable chance of developing new TMJ-symptoms (21%) and even condylar atrophy (De Clercq et al., 1994) in those high angle (SN/GoMe > 32 °) mandibular deficiency patients having bimaxillary operations. The same conclusions were also found by Kerstens et al., 1989b, 1990).

MATERIAL AND METHOD

A retrospective study was performed on the osteotomy patients operated on in the division of Maxillo-Facial Surgery of the General Hospital St. John, Bruges, in the period from 1.10.90 till 1.10.92. Cleft patients, patients with laterognathia and those treated by genioplasty only, were excluded from this study. Only those patients with good preoperative and postoperative TMJ data were retained for further investigation (317 patients in total). Only the 143 patients, with a no/lo angle mandibular deficiency deformity, treated by mandibular advancement, and the 53 high angle, absolute mandibular retrognathism patients having bimaxillary operations, were selected. The files of these 196 patients were investigated. There were 46 males in the sample and the mean age was 25 years (range 13 to 42 years). The inclusion criteria for the no/lo angle mandibular deficiency patient was a mandibular plane angle of less than, or equal to, 32 degrees. This angle between Sella-Nasion (SN) and Gonion-Menton (GoMe) was measured on the cephalometric radiograph itself. These cephalometric radiographs were standardised by a focus median plane distance of 4.00 m and a film median plane distance of 0.17 m. The high angle mandibular deficiency patient has a mandibular plane angle greater than 32 degrees (Wolford et al., 1978; Kerstens et al. 1989b). The patients were examined by palpation for joint noise 195

196 Journalof Cranio Maxillo-FacialSurgery and muscle tenderness, pain, movements and limitation. This clinical examination was carried out, initially within one week prior to the operation and after a minimum period of 6 months postoperatively. All the 196 patients were operated on with negligible variations in surgical technique (Wassmund, 1935; Trauner and Obwegeser, 1957; Hunsuck, 1968). Bilateral sagittal split osteotomy was used for mandibular advancement and maxillary displacement was corrected by a Le Fort I osteotomy. Rigid fixation, without intermaxillary fixation, was always used (Lindorf, 1986; Mommaerts, 1991; Abeloos et al., 1993). Most of the patients used light training elastics for 2 weeks from the second postoperative day.

Postoperatively, 35 (17.8 %) of the 196 patients had TMJ symptoms. In the group of no/lo angle deficiency patients, 43 of the 143 (30.0 %) had TMJ symptoms before surgery, 31 (72.1%) had fewer or no TMJ symptoms after surgery. In the high angle group 9 of the 53 patients (16.8%) had preoperative TMJ symptoms, 3 (33.3 %) had fewer or no TMJ symptoms postoperatively (Figs 1, 2). From the 144 asymptomatic patients, 17 (11.9 %) developed new TMJ symptoms after operation. There were 100 patients from the no/lo angle deficiency group asymptomatic preoperatively; 9 (9%) developed TMJ symptoms and from the 44 asymptomatic patients from the high angle 8 (18.1%) developed TMJ symptoms (Figs 3, 4). There is a significant difference between the prevalence of TMJ symptoms preoperatively and postoperatively for the total group (p = 0.025, Mc Nemar) and for the no/lo angle deficiency group (p = 0.0001, Mc Nemar). There is no significance for the high angle group (p = 0.228, Mc Nemar). We see that the sagittal

RESULTS 52 of the 196 patients (26.5 %) reported preoperative TMJ dysfunction; 34 patients improved and 17 developed new TMJ symptoms postoperatively.

60

. . . . . . . . . . . . . .

50

•

~(16.8%)

1/10/90-1/10/92

..................................

40

30

I~

high angle angle1 low/normal

~,~i~ (26.4%) ............. j!~,~!~

43 I(3o%) 20

21 (14.6%)

10

0

PREOP

POSTOP

Fig. 1 - Distribution of symptomaticpatients preoperativelyand postoperativelyfor the 2 groups (n = 196).

1/10/90-1/10/92 250

.............................................................................................

200

150

sympl [D sym pt (rTno

144 100

.................. 100

0

..........................

total group

Low/normal angle

(16.8%) High angle

Fig. 2- Distribution of the numberof patients with positive/negativesymptomspreoperatively(n = 196).

Temporomandibularjoint symptomsin an orthognathicsurgerypopulation 197 250

1/10/90-1/10/92

200

150

161

[[~no sympt Dsympt i

100

122

"

50

~(17.8%) ~

114.6%)~ ( 2 6 . 4 % )

Total group

Low/normal

p=0,025 (Mc Nemar)

p=0,0001 (Mc Nemar)

High

p=0,228 (Mc Nemar)

Fig. 3 Distribution of the number of patients with positive/negativesymptomspostoperatively(n = 196).

1/10/90-1/10/92 160

140 120 100 608040 127 total group

..... r-7nosympt ~newsympt

~ Low/normalangle

High angle

Fig. 4 Preoperativelyasymptomaticpatients (n = 144) developingnew TMJ symptomspostoperatively.

splitting of the mandibular ramus in combination with with a Le Fort I osteotomy in the treatment of the high angle patient results in the highest number of postoperative TMJ symptoms, namely 14 (26.4%) versus 9 (16.8 %) preoperatively. The treatment of the lo/no angle deficiency group (isolated sagittal splitting osteotomy) only gives 21 (14.6 %) patients with postoperative symptoms, although preoperatively 43 (30.0%) patients had TMJ symptoms (Figs 1, 2, 3 and 4).

DISCUSSION The prevalence of symptoms of temporomandibular joint disorders before and after orthognathic surgery has been documented in several clinical studies (Karabouta and Martis, 1985; Magnusson, 1986;

Hackney et al., 1989) most of which have reported a lower prevalence at follow-up than before surgery (Karabouta and Martis, 1985; Magnusson, 1986). The appearance of iatrogenic TMJ symptoms after orthognathic surgery has been suggested, however, (Trauner and Obwegeser, 1957, Hunsuck, 1968; Kerstens et al., 1989; De Clercq et al., 1993) and a 60% prevalence of TMJ symptoms after Le Fort I osteotomy with superior repositioning of the maxilla was reported in a series of patients who were asymptomatic before surgery (Hackney et al., 1989). ' Cracking' has been described in 45 % of the patients after sagittal split osteotomy (Freihofer and Petresevic, 1975) and an other study reported fibrous ankylosis after sagittal split and bimaxillary osteotomies using rigid and intermaxillary fixation (Nitzan and Dolwick, 1989). These observations have led clinicians to speculate that there might be an association between significant occlusal disharmonies and TMJ disorders

198 Journal of Cranio Maxillo-Facial Surgery

(Nickerson and Moystad, 1983). Several investigators (Kerstens et al., 1989b; White and Dolwiek, 1992; Link and Niekerson, 1992; De Clercq et al., 1993) found that in an orthognathic population group TMJ, dysfunction was more prevalent in patients with class II skeletal deformities, low angle and deep bite. These patients with TMJ dysfunction generally improve after orthognathic surgery. In our study also, we saw in this group 30 % of the patients with preoperative symptoms and an improvement in 72.1% after operation. In our high angle group having bimaxillary surgery 16.8 % have preoperative problems with an improvement from only 33.3% but with creation of 18.1% new iatrogenic symptoms after operation. Kerstens et al. (1989b) found similar outcomes. The results of these studies are also in accordance with our previous findings (De Clereq et al., 1993). These results can be explained by a different loading of the joint and different muscle rehabilitation (Wessberg and Epker, 1981; O'Ryan and Epker, 1984). The morphology of the TMJ varies between skeletal class II open bite (high angle) and skeletal class II deep bite (low angle) patients. O'Ryan and Epker, 1984 did anatomical and radiographic examinations and they found a clear difference in external and internal morphology of the mandibular condyle. They concluded that the functional loading patterns in each of these TMJ are significantly different. The trabeculae are aligned parallel to the mean vector of compressive loading. In comparison with the open bite class II, they found in the deep bite class II variant that the trabeculae, in anterioposterior view, are more dense and vertically oriented. In the deep bite patient, the mean vector of condylar loading, constructed from these trabecular patterns, is of a greater magnitude and directed more vertically than in the open bite patient. The steepness and prominence of the articular eminence is reported to be related to a deep overbite (Boering, 1979). A correlation between the prominence of the articular eminence and the development of anterior disc displacement in the TMJ has been put forward by several authors (A tkinson and Bates, 1983 ; Hallet al., 1985; De Bont et al., 1986; Kerstens et al., 1989). The high number of TMJ symptoms in the lo/no angle group preoperatively can be explained by this higher condylar compressive loading during masticatory function (Hylander, 1979). The condyles bear the greatest amount of compressive loading, especially during incisal mastication (Hylander and Bays, 1979). The condyles are brought forward out of the deep fossa and lie opposite the crest of the articular eminence. In the open bite group, on the other hand, there is no incisal mastication. The open-bite variant prevents incisal function and as the condyles bear the greatest compressive loads during incisal function, the condylar loading is minimised by a relative lack of incision in this group (O'Ryan and Epker, 1984). Electromyographic studies indicate that patients with a high angle exhibit decreased electromyographic

activity when compared with low angle patients, in a given task (Moller, 1966; Ingervall and Thilander, 1974). Diminished masticatory force, as measured by isometric maximal molar bite, is also a feature of this high angle group (Ringqvist, 1973). As a result of the altered masticatory muscle anatomy and function existing in these high angle individuals, they generate significantly less occlusal biting forces than normal and they put proportionately less strain on the TMJ. Orthognathic surgery will have an indirect influence on the function of the TMJ. This function is changed by repositioning the maxilla, the mandible or both. The deep bite patients change into a more open pattern and vice versa. The loading of the condyle is decreased by the operation in the low angle group and seems to produce less TMJ symptoms. These patients had only a mandibular advancement with a relieving clockwise rotation of the mandible (O'Ryan and Epker, 1983). Conversely, in the high angle group, an increased loading by creating a more deep bite pattern can be seen. The position of the condyle relative to the articular eminence is also changed in this group, because of autorotation following the Le Fort I intrusion osteotomy (Greebe and Tuinzing, 1987). The position of the disc will be more anterior on the condylar head and the articular eminence angle will be relatively steeper. The bimaxillary surgery and a more counter clockwise rotation of the mandible in this high angle group produce more compressive loads on the ultrastructure of the articular cartilage of the mandibular condyle. O'Ryan and Epker (1984), also mentioned that the condyles of this high angle group in comparison with the low angle group are small and in a more posterior direction. The trabeculae in these high angle condyles are sparse and do not demonstrate a special orientation, contrary to the low angle variant. These are all factors that can explain a greater prevalence of TMJ symptoms postoperatively in this high angle group. Condylar resorption is also seen more frequently in this group of patients after bimaxillary surgery (Kerstens et al., 1990; De Clercq et al., 1994). A prospective study, in collaboration with our TMJ clinic, is set up to confirm and extend these findings. In particular the assessment of the subjective TMJ symptoms is studied using a patient questionnaire and visual analog scales. Conclusion

This study confirms previous statements that the incidence of TMJ symptoms preoperatively in the lo/no angle group and in the total group is significantly higher than postoperatively. There are more preoperative TMJ symptoms in the low and normal angle group in comparison with the high angle group. The chance is higher that the TMJ symptoms in the low and normal angle group will improve after isolated mandibular surgery. The chance of developing new TMJ symptoms is higher in the high angle group after bimaxillary surgery.

Temporomandibular joint symptoms in an orthognathic surgery population

References Abeloos, J., C. De Clercq, L. Neyt : Skeletal stability following miniplate fixation in bilateral sagittal split osteotomy for mandibular advancement. J. Oral Maxillofac. Surg. 51 (1993) 366-369 Atkinson, W. B., R. E. Bates." The effect of the angle of the articular eminence on articular disc displacement. J. Prosthet. Dent. 49 (1983) 554-555 Boering, G. : Anatomical and physiological considerations regarding the TMJ. Int. Dent. J. 29 (1979) 245-251 De Bont, L. G. M., G. Boering, R. S. B. Liem, F. Eulderink, P. L. Westesson: Osteoarthrosis and internal derangement of the TMJ. A light microscopic study. J. Oral Maxillofac. Surg. 44 (1986) 634-643 De Clercq, C., L. Neyt, M. Mommaerts, J. Abeloos, B. De Mot." Kaakgewrichtssymptomen in orthognatische chirurgie: een retrospectief onderzoek. Acta Store. Belg. 2 (1993) 77-85 De Clercq, C., L. Neyt, M. Mommaerts, J. Abeloos, B. De Mot: Condylar resorption in orthognathic surgery: a retrospective study. Int. J. Adult Orthod. Orthognath. Surg. 9 (1994) 233-240. Freihofer, H. P., D. Petresevie : Late results after advancing the mandible by sagittal splitting of the rami. J. Max.-Fac. Surg. 3 (1975) 250-257 Greebe, R. G., D. B. Tuinzing : Superior repositioning of the maxilla by a Le Fort I osteotomy. A review of 26 patients. J. Oral Surg. 63 (1987) 158-162 Hackney, F. L., or. E. Van Siekels, P. V. Nummikoski: Condylar displacement and TMJ dysfunction following bilateral sagittal split osteotomy and rigid fixation. J. Oral Maxillofac. Surg. 47 (1989) 223-229 Hall, M. B., C. C. Gibbs, A. G. Sclar : Association between the prominence of the articular eminence and displaced TMJ discs. J. Craniomandibular Prac. 3 (1985) 237~39. Hunsuek, E. E. : A modified intraoral sagittal splitting technique for correction of mandibular prognathism. J. Oral Surg. 26 (1968) 249-272 Hylander, W. L. : An experimental analysis of TMJ reaction force in Macaques. Am. J. Phys. Anthropol. 51 (1979) 433M56 Hylander, W. L., R. Bays: An in vivo strain-gauge analysis of the squamosal-dentary joint reaction force during mastication and ineisal biting in the Macaca mulata and Macaca fasicularis. Arch. Oral Biol. 24 (1979) 689-697 Ingervall, B., B. Thilander : Relation between facial morphology and activity of the masticatory muscles. J. Oral Rehabil. 1 (1974) 131-147 Karabouta, L, C. Martis: The TMJ dysfunction syndrome before and after sagittal split osteotomy of the rami. J. Max.-Fac. Surg. 13 (1985) 18~192 Kerstens, H. C., D. B. Tuinzing, R. P. Golding, W. A. M. van der Kwast." Inclination of the temporomandibular joint eminence and anterior disc displacement. Int. J. Oral Maxillofac. Surg. 18 (1989a) 228-232 Kerstens, H. C., D. B. Tuinzing, W. A. M. van der Kwast : Temporomandibular joint symptoms in orthognathic surgery. J. Craniomaxillofac. Surg. 17 (1989b) 215-218 Kerstens, H. C., D. B. Tuinzing, R. P. Golding, W. A. M. van der Kwast: Condylar atrophy and osteoarthrosis after bimaxillary surgery. Oral Surg. Oral Med. Oral Path. I. 69 (1990) 274-280 Laskin, D. M., W. A. Ryan, C. S. Greene: Incidence of temporomandibular symptoms in patients with major skeletal

199

malocclusions: a survey of oral and maxillofacial surgery training programs. Oral Surg. Oral Med. Oral Pathol. 61 (1986) 53%541 Lindorf, H. H. : Sagittal ramus osteotomy with tandem screw fixation. J. Max.-Fac. Surg. 14 (1986) 311-316 Link, J., J. Nickerson: TMJ internal derangements in an orthognathic surgery population. Int. J. Adult Orthodont. Orthognath. Surg. 7 (1992) 161-169 Magnusson, T., G. Ahlborg, K. Finne : Changes in temporomandibular joint pain-dysfunction after surgical correction of dentofacial anomalies. Int. J. Oral Maxillofac. Surg. 15 (1986) 702712 Moller, E. : The chewing apparatus. An electromyographic study of the action of the muscles of mastication and its correlation to facial morphology. Acta Physiol. Scand. 69 (1966) Suppl. 280 1-229 Mommaerts, M. Y. : Slot osteosynthesis technique (SLOT) for sagittal ramus split osteotomies. A method to optimize occlusal control and condylar seating. J. Craniomaxillofac. Surg. 19 (1991) 14%149 Nickerson, J. W., A. Moystad: Observations on individuals with radiographic bilateral condylar remodelling. J. Craniomandib. Pract. 1 (1983) 20-28 Nitzan, D. W., M. F. Dolwiek : TMJ fibrous ankylosis following orthognathic surgery: Report of 8 cases. Int. J. Adult Orthodont. Orthognath. Surg. 4 (1989) 7-17 O'Ryan, F., B. N. Epker: Surgical orthodontics and the TMJ. II. Mandibular advancement via modified sagittal split ramus osteotomies. Am. J. Orthod. 83 (1983) 418M27 O'Ryan, F., B. N. Epker: TMJ function and morphology: Observation on the spectra of normalcy. Oral Surg., Oral Med., Oral Pathol. 58 (1984) 272-282 Ringqvist, M. : Isometric bite force and its relation to dimensions of the facial skeleton. Acta Odontol. Scand. 31 (1973) 35-42 Trauner, R., H. L. Obwegeser : Surgical correction of mandibular prognathism and retrognathism with considerations of genioplasty. Operation methods for microgenia and distocclusion. Oral Surg. 10 (1957) 787-792 Wassmund, M. : Lehrbuch der Praktische Chirurgie des Mundes und der Kiefer. Leipzig. 1935 Wessberg, G. A., B. N. Epker : The influence of mandibular advancement via modified sagittal split ramus osteotomy on the masticatory musculature. Oral Surg. 52 (1981) 114-117 White, C. S., F. Dolwick." Prevalence and variance of temporomandibular dysfunction in orthognatic surgery patients. Int. J. Adult Orthod. Orthognath. Surg. 7 (1992) 7-14 Wolford, L. M., G. Walker, S. Sehendel, L. T. Fish, B. N. Epker : Mandibular deficiency syndrome. I. Clinical delineation and therapeutic significance. Oral Surg. Oral Med. Oral Pathol. 45 (1978) 329-348

Calix de Clereq, MD, LDS Division of Maxillofacial Surgery A.Z. St.-Jan Ruddershore 10 B-8000 Brugge Belgium Paper received: 8 June 1994 Accepted: 10 January 1995