- Email: [email protected]
The problems of correction of asymmetric mandibular prognathism
Int. J. Oral Surg. 1974: 3:229-233 (Key words: face, asymlnetry; llrognathism; stlrgery, oral)
The problems of correction of asymmetric mandibular prognathism A L A G U M B A L. N W O K U , R A M O N P A L O M E R O - R O D R I G U E Z A N D HANS-H. H O R C H
Clinic Jor Maxillofacial and Plastic Surge~3, oJ the Face, Westdeutsche Kieferkllnik, University of Diisseldor[, Dilsseldorf, West Germany The percentage of prognathism associated with mandibular asymmetry is small. The main causes of asymmetry are unilateral condylar hyperplasia and normal non-progressive mandibular asymmetry. The etiology is sometimes hereditary. Of 122 cases of mandibular prognathism corrected in the Clinic for MaxilIofacial and Plastic Surgery, Westdeutsche Kieferklinik, University of DtisseIdorf from 1953-1974, only nine were associated with mandibular asymmetry. Of these nine cases, two showed relapse after correction. A surgical technique for correction of asymmetric mandibular prognathism, and suggestions for checking relapse, have been included. ABSTRACT
-
-
Angle's Class III malocclusion, often referred to as m a n d i b u l a r prognathism, is the mandibulo-maxitlary a n o m a l y w h i c h most often requires correction. M a n y authors h a v e described this anomaly, and a wide range of surgical techniques f o r its correction have been reported in the literature2, 5, ~1,it, 12,1~, iT, o1. Very few, however, h a v e reported on problems arising in the treatment of prognathism associated with mandibular asymmetryT, s, s0 A l t h o u g h the percentage of cases with prognathism associated with m a n dibular asymmetry is small, this combination is sufficiently c o m m o n to m e r i t discussion.
Material Of 122 cases of mandibular prognathism treated in the Clinic for Maxillofacial and Plastic
Surgery of the Face, Westdeutsche Kieferklinik, University of Dtisseldorf from 1 April 1953 to 31 March 1974, nine were associated with mandibular asymmetry. Females were more frequently affected than males. Of the nine cases under review, eight were female and one was male. The age at onset of disease was usually during puberty. At the time of hospital admission, the youngest patient was 16 years and the oldest 42 years old. Most of the patients (5) were between the ages of 17 and 21. The cases showed varying degrees of mandibular prognathism combined with a lateral deviation of the mandible in its centric position, usually as the result of unequal subcondylar growth. In every case the deviation was to the non-affected side, with crossbite and prominence of the chin on that side. In addition, there was the negative overjet commonly found in mandibuiar prognathism. Radiographs showed enlargement or elongation of the condyle on the affected side (Fig. 1). In one case (S.U., female, aged 17), a hereditary factor 2o seemed to be present. The patient had a slight prognathic profiIe and a
230
N W O K U , P A L O M E R O - R O D R I G U E Z AND H O R C H show the preoperative and postoperative profile and occlusion.
~ i::~ ~
~,"~' ~i,~i~y84184184
,m !i::84184
Treatment
~:~!~i!84
Fig. 1. Radiograph showing unequal condylar growth. The right condylar head is deformed.
pronounced mandibular asymmetry. There was crossbite beginning from the lateral incisors to the last molar of the right side. Her ll-year-old sister, as well as her 8-year-old brother, had exactly the same occlusal picture. Figs. 2-3
One case was corrected using the REHRMANN modification 17 (1967) of the LINDEMANNprocedure, and another with the D1NGMANprocedure. The remaining seven cases were corrected with sagittal osteotomy of tile ramus as described by OBWEG:ESERI.:I,1,1. In one case, in which there was a history of clicking of the right temporomandibular joint, which was the affected side, a unilateral arthroereisis according to REHRMANNUl, 17 W a s achieved concomitandy, intermaxitlary fixation was applied for 6-8 weeks.
Results O f the nine corrected cases under review, the results in five w e r e good, in two satisfactory, and two cases showed relapse. In no case, however, was the degree of relapse equal to the preoperative situation. A good
Fig,. 2. A, preoperative photograph of patient showing mandibular asymmetry with deviation of chin to the right. B, postoperative result.
CORRECTION OF MANDIBULAR PROGNATHISM
231
result was assessed to be one in which there was practically no change in the occlusion achieved on study casts and during operation (Fig. 3). A satisfactory result was one in which there was an edge-to-edge occlusion of the anterior teeth. An unsatisfactory result was one in which prognathic occlusion recurred.
Discussion
Fig. 3. A, Occlusion of patient from Fig. 2 showing crossbite of the right side, and deviation of the midline of mandibular teeth to the right side. B, after correction.
There is agreement among m a n y attthors l, ~, 4, ~0 that the surgical correctio~n of the mandibular prognathism could be undertaken about the 16th year of life. But in mandibular prognathism associated with asymmetry, it is usually best to postpone surgery until subcondylar growth has shown n o further activity for about 6 months clinically and radiographically. Otherwise, the deformity may recur after correction. I n fact, one of the two cases which relapsed was our youngest patient, who was 16 years old at the time of operation.
Fig. 4. A, photograph before surgical correction. B, postoperative result.
232
NWOKU, PALOMERO-RODRIGUEZ AND HORCH
Fig. 5. A, occlusion of patient from Fig. 4 be-
fore surgical correction. B, after correction. Our findings indicate that this type of a s y m m e t r y is not constant, but varies from case to case. T h e two main deformities present here are m a n d i b u l a r prognathism and asymmetry, the latter manifesting itself either as a progressive increase in the mandibular length anteropostefiorly, or as an increase in the height of the affected side. This clinical picture h a s been referred to as condylar hyperplasia. I n cases with a vertical growth, the horizontal ramus of the diseased side is displaced downwards, and the lower b o r d e r becomes convex. T h e Ievel of the occlusal plane is Iowered, with subsequent open bite on the affected side. HOVELL ~, 10 has included unilateral condylar hyperplasia, n o r m a l non-progressive mandibular asymmetry, fibrous dysplasia and unilaterM m a n d i b u l a r agenesis as causative factors for mandibular asymmetry. The chief problem in diagnosis is usually to distinguish between hormonally-induced asymmetry and the hereditary type. It is therefore advisable that any patients who
present possible symptoms of hormonal stimulation undergo an endocrinologic evaluation. A critical analysis of the results shows a higher incidence of relapse in the correction of asymmetric mandibular prognathism in comparison with those of the cases without asymmetry. BIERMANN't found unsatisfactory results in 11.5% of our prognathic cases operated during the 17-year period of 19531970. Using BIERMANN'S criteria for assessment, we found relapse in 22.2% of those whose asymmetric prognathism had been corrected. This is a higher margin than is ordinarily found in the correction of mandibular prognathism. It must be stressed, however, that the statistical evaluation of small numbers cannot be relied upon. OBWEGESERla, HOVELL10 and REICHENBACrt etal. ~n blame the masseter-pterygoideus sling for the relapse and suggest that these muscles be detached. DINGMANg operates if identical cephalometrie radiographs show no further changes within a 6-month interval. A 6-month check-up will usually suffice to show whether the asymmetry is static or progressive. Mounted dental casts, radiographs and cephalometrics should be done during the first consultation, and kept for later comparison. The choice of surgical technique is very important ilx checking relapse. Of the various surgicN techniques available, the Obwegeser sagittal splitting procedure of the ramus has proved very successful for us. The two large medullary surfaces created by the sagittal splitting greatly enhance bony union. Furthermore, an extended intermaxillalT fixation for at least 8 weeks is indicated. Sometimes asymmetry of the chin is stiIl present after correction of the occlusion. I n such cases a subsequent correction of the chin, as recommended by OBWe~ESERla, is necessaw. I t is best to wait until healing of the first operation is complete, so that the
CORRECTrON OF MANDIBULAR PROGNATHISM degree of correction required by the chin can be correctly assessed. T h e too high mandible is corrected by shaving off the lower border, care being taken to. preserve the mandibular canal. We did not treat any of our cases with condy[ectomy on the affected side as suggested by HOVELLg.
References 1. A~AUSEN, G.: Aufgaben nnd Leistungen der operativen Kiefer-orthopaedie. Fortschr. Kieferorthop. 1952: 13: 24-36. 2. BABCOCK,W. W.: The field of osteoplastic operations for the correction of deformities of the jaws. Dent. Items Interest 1910: 32: 439. 3. BECKER, R.: Erfolge und Misserfolge der Progeniebehandlung und ihre Ursachen. Dtsch. Zahnaerztebl. 1966: 20: 766-776. 4. BIERM~XNN,B.: Ergebnisse der Progeaieoperation in der Westdeutschen Kieferklinik (Differentialtherapeutische Analyse yon 98 Ftillen). Thesis, Dtisseldo:rf 1973, p. 14-25. 5. CONVERSE, M. & SHAPIRO, H. H.: Treatment of developmental malformations of the jaws. Plast. Recoastr. Surg. 1952: 10: 473-510. 6. DINGMAN, R. O.: Surgical correction of mandibular prognathism: an improved method. At**. J. Orthodont. 1944: 30: 683692. 7. EGYEDI, ~P.: Problematik der Chirurgie der Progenie. Thesis, Z[irich 1964, p. 39-46. 8. FICKLING, B. W. & FORDYCE, G. L.: Mandibular osteotomy for facial asymmetry. Proc. R. Soe. Med. 1955: 48: 989. 9. HOVELL, J'. H.: Condylar hyperplasia. Br. g. Oral Surg. 1963: 1: 105-111.
Address:
Clinic for Maxillofacial and Plastic Surgery of the Face WestdeuL~che Kieferklinik 4- Diisseldorf Moorenstrasse 5 West Germany
2.33
10. HOVELL, J. I-I.: Surgical correction of facial deformity. Ann. R. Coll. Surg. (EngI.) 1970: 46: 92-107. 11. KOSTECKA, F.: Die chirurgische Therapie der Progenie. Zahnaerztl. Rdsch. 1931: 40: 670-688. 12. LtNDEMANN,H., BROHN, C. & SCHMIDT, G'.: Die Eingriffe bei der Progenie und Opisthogenie. In: KLEINSCHMIDT, O. (ed.): Operatire Chh'urgie. Berlin 1943, p. 711. 13. OBWEGESER,H. L.: The surgical correction of mandibular prognathism and retrognathia with consideration of gonioplasty. Oral Surg. 1957: 10: 677-689. 14. OBWEGESER, t-I. L.: The indications for surgical correction of mandibular deformity by the sagittal splitting technique. Br. J. Oral Surg. 1963: 1: 157-171. ]5. PERTHES, G.: Operative Korrektur der Progenie. Zbl. Chir. I922: 49: 1540-1541. 16. RaI-IRMANN, A.: Osteoplastische Verriegelung des Kiefergelenks in Fg.llen yon habitueller Luxation. Zbl, Chlr. 1956: 81: 521531. 17. REHR~ANN,A.: Horizontale Osteotomie der Unterkieferaeste mit Drahtnaht zur Behebung der Progenie mit Erhaltung der urspruenglichen Position der Gelenkkoepfe. Dtsch. Zahn-, Mund-, Kieferheilkd. 1967: 49: 72-76. 18. REHRMANN,A. & KREIDLER, J.: Late results after arthroereisis of the temporomandibufar joint by autop]astic bone graft. 1. Maxitlo/ac. Surg. 1973: 1: 99-11)3. 19. REICHENBACH, E., KOELE, H. & BRUECKL, H.: Chirurgische Kie/erorthopaedie. Johann Ambrosius Barth, Leipzig 1970, p. 17-123. 20. ROWE, N. L.: The etiology, clinical features and treatment of mandibular deformity. Br. Dent. J. 1960: 108: 45-64. 21. TRAUNER, R. & OBWEGESEP,, H.: Zur Operationstechnik bei der Progenie und andeten Unterkieferanomalien. Dtsch. Zahn-, Mund-, Kie/erheilkd. 1955: 23: 1-26.
The problems of correction of asymmetric mandibular prognathism A L A G U M B A L. N W O K U , R A M O N P A L O M E R O - R O D R I G U E Z A N D HANS-H. H O R C H
Clinic Jor Maxillofacial and Plastic Surge~3, oJ the Face, Westdeutsche Kieferkllnik, University of Diisseldor[, Dilsseldorf, West Germany The percentage of prognathism associated with mandibular asymmetry is small. The main causes of asymmetry are unilateral condylar hyperplasia and normal non-progressive mandibular asymmetry. The etiology is sometimes hereditary. Of 122 cases of mandibular prognathism corrected in the Clinic for MaxilIofacial and Plastic Surgery, Westdeutsche Kieferklinik, University of DtisseIdorf from 1953-1974, only nine were associated with mandibular asymmetry. Of these nine cases, two showed relapse after correction. A surgical technique for correction of asymmetric mandibular prognathism, and suggestions for checking relapse, have been included. ABSTRACT
-
-
Angle's Class III malocclusion, often referred to as m a n d i b u l a r prognathism, is the mandibulo-maxitlary a n o m a l y w h i c h most often requires correction. M a n y authors h a v e described this anomaly, and a wide range of surgical techniques f o r its correction have been reported in the literature2, 5, ~1,it, 12,1~, iT, o1. Very few, however, h a v e reported on problems arising in the treatment of prognathism associated with mandibular asymmetryT, s, s0 A l t h o u g h the percentage of cases with prognathism associated with m a n dibular asymmetry is small, this combination is sufficiently c o m m o n to m e r i t discussion.
Material Of 122 cases of mandibular prognathism treated in the Clinic for Maxillofacial and Plastic
Surgery of the Face, Westdeutsche Kieferklinik, University of Dtisseldorf from 1 April 1953 to 31 March 1974, nine were associated with mandibular asymmetry. Females were more frequently affected than males. Of the nine cases under review, eight were female and one was male. The age at onset of disease was usually during puberty. At the time of hospital admission, the youngest patient was 16 years and the oldest 42 years old. Most of the patients (5) were between the ages of 17 and 21. The cases showed varying degrees of mandibular prognathism combined with a lateral deviation of the mandible in its centric position, usually as the result of unequal subcondylar growth. In every case the deviation was to the non-affected side, with crossbite and prominence of the chin on that side. In addition, there was the negative overjet commonly found in mandibuiar prognathism. Radiographs showed enlargement or elongation of the condyle on the affected side (Fig. 1). In one case (S.U., female, aged 17), a hereditary factor 2o seemed to be present. The patient had a slight prognathic profiIe and a
230
N W O K U , P A L O M E R O - R O D R I G U E Z AND H O R C H show the preoperative and postoperative profile and occlusion.
~ i::~ ~
~,"~' ~i,~i~y84184184
,m !i::84184
Treatment
~:~!~i!84
Fig. 1. Radiograph showing unequal condylar growth. The right condylar head is deformed.
pronounced mandibular asymmetry. There was crossbite beginning from the lateral incisors to the last molar of the right side. Her ll-year-old sister, as well as her 8-year-old brother, had exactly the same occlusal picture. Figs. 2-3
One case was corrected using the REHRMANN modification 17 (1967) of the LINDEMANNprocedure, and another with the D1NGMANprocedure. The remaining seven cases were corrected with sagittal osteotomy of tile ramus as described by OBWEG:ESERI.:I,1,1. In one case, in which there was a history of clicking of the right temporomandibular joint, which was the affected side, a unilateral arthroereisis according to REHRMANNUl, 17 W a s achieved concomitandy, intermaxitlary fixation was applied for 6-8 weeks.
Results O f the nine corrected cases under review, the results in five w e r e good, in two satisfactory, and two cases showed relapse. In no case, however, was the degree of relapse equal to the preoperative situation. A good
Fig,. 2. A, preoperative photograph of patient showing mandibular asymmetry with deviation of chin to the right. B, postoperative result.
CORRECTION OF MANDIBULAR PROGNATHISM
231
result was assessed to be one in which there was practically no change in the occlusion achieved on study casts and during operation (Fig. 3). A satisfactory result was one in which there was an edge-to-edge occlusion of the anterior teeth. An unsatisfactory result was one in which prognathic occlusion recurred.
Discussion
Fig. 3. A, Occlusion of patient from Fig. 2 showing crossbite of the right side, and deviation of the midline of mandibular teeth to the right side. B, after correction.
There is agreement among m a n y attthors l, ~, 4, ~0 that the surgical correctio~n of the mandibular prognathism could be undertaken about the 16th year of life. But in mandibular prognathism associated with asymmetry, it is usually best to postpone surgery until subcondylar growth has shown n o further activity for about 6 months clinically and radiographically. Otherwise, the deformity may recur after correction. I n fact, one of the two cases which relapsed was our youngest patient, who was 16 years old at the time of operation.
Fig. 4. A, photograph before surgical correction. B, postoperative result.
232
NWOKU, PALOMERO-RODRIGUEZ AND HORCH
Fig. 5. A, occlusion of patient from Fig. 4 be-
fore surgical correction. B, after correction. Our findings indicate that this type of a s y m m e t r y is not constant, but varies from case to case. T h e two main deformities present here are m a n d i b u l a r prognathism and asymmetry, the latter manifesting itself either as a progressive increase in the mandibular length anteropostefiorly, or as an increase in the height of the affected side. This clinical picture h a s been referred to as condylar hyperplasia. I n cases with a vertical growth, the horizontal ramus of the diseased side is displaced downwards, and the lower b o r d e r becomes convex. T h e Ievel of the occlusal plane is Iowered, with subsequent open bite on the affected side. HOVELL ~, 10 has included unilateral condylar hyperplasia, n o r m a l non-progressive mandibular asymmetry, fibrous dysplasia and unilaterM m a n d i b u l a r agenesis as causative factors for mandibular asymmetry. The chief problem in diagnosis is usually to distinguish between hormonally-induced asymmetry and the hereditary type. It is therefore advisable that any patients who
present possible symptoms of hormonal stimulation undergo an endocrinologic evaluation. A critical analysis of the results shows a higher incidence of relapse in the correction of asymmetric mandibular prognathism in comparison with those of the cases without asymmetry. BIERMANN't found unsatisfactory results in 11.5% of our prognathic cases operated during the 17-year period of 19531970. Using BIERMANN'S criteria for assessment, we found relapse in 22.2% of those whose asymmetric prognathism had been corrected. This is a higher margin than is ordinarily found in the correction of mandibular prognathism. It must be stressed, however, that the statistical evaluation of small numbers cannot be relied upon. OBWEGESERla, HOVELL10 and REICHENBACrt etal. ~n blame the masseter-pterygoideus sling for the relapse and suggest that these muscles be detached. DINGMANg operates if identical cephalometrie radiographs show no further changes within a 6-month interval. A 6-month check-up will usually suffice to show whether the asymmetry is static or progressive. Mounted dental casts, radiographs and cephalometrics should be done during the first consultation, and kept for later comparison. The choice of surgical technique is very important ilx checking relapse. Of the various surgicN techniques available, the Obwegeser sagittal splitting procedure of the ramus has proved very successful for us. The two large medullary surfaces created by the sagittal splitting greatly enhance bony union. Furthermore, an extended intermaxillalT fixation for at least 8 weeks is indicated. Sometimes asymmetry of the chin is stiIl present after correction of the occlusion. I n such cases a subsequent correction of the chin, as recommended by OBWe~ESERla, is necessaw. I t is best to wait until healing of the first operation is complete, so that the
CORRECTrON OF MANDIBULAR PROGNATHISM degree of correction required by the chin can be correctly assessed. T h e too high mandible is corrected by shaving off the lower border, care being taken to. preserve the mandibular canal. We did not treat any of our cases with condy[ectomy on the affected side as suggested by HOVELLg.
References 1. A~AUSEN, G.: Aufgaben nnd Leistungen der operativen Kiefer-orthopaedie. Fortschr. Kieferorthop. 1952: 13: 24-36. 2. BABCOCK,W. W.: The field of osteoplastic operations for the correction of deformities of the jaws. Dent. Items Interest 1910: 32: 439. 3. BECKER, R.: Erfolge und Misserfolge der Progeniebehandlung und ihre Ursachen. Dtsch. Zahnaerztebl. 1966: 20: 766-776. 4. BIERM~XNN,B.: Ergebnisse der Progeaieoperation in der Westdeutschen Kieferklinik (Differentialtherapeutische Analyse yon 98 Ftillen). Thesis, Dtisseldo:rf 1973, p. 14-25. 5. CONVERSE, M. & SHAPIRO, H. H.: Treatment of developmental malformations of the jaws. Plast. Recoastr. Surg. 1952: 10: 473-510. 6. DINGMAN, R. O.: Surgical correction of mandibular prognathism: an improved method. At**. J. Orthodont. 1944: 30: 683692. 7. EGYEDI, ~P.: Problematik der Chirurgie der Progenie. Thesis, Z[irich 1964, p. 39-46. 8. FICKLING, B. W. & FORDYCE, G. L.: Mandibular osteotomy for facial asymmetry. Proc. R. Soe. Med. 1955: 48: 989. 9. HOVELL, J'. H.: Condylar hyperplasia. Br. g. Oral Surg. 1963: 1: 105-111.
Address:
Clinic for Maxillofacial and Plastic Surgery of the Face WestdeuL~che Kieferklinik 4- Diisseldorf Moorenstrasse 5 West Germany
2.33
10. HOVELL, J. I-I.: Surgical correction of facial deformity. Ann. R. Coll. Surg. (EngI.) 1970: 46: 92-107. 11. KOSTECKA, F.: Die chirurgische Therapie der Progenie. Zahnaerztl. Rdsch. 1931: 40: 670-688. 12. LtNDEMANN,H., BROHN, C. & SCHMIDT, G'.: Die Eingriffe bei der Progenie und Opisthogenie. In: KLEINSCHMIDT, O. (ed.): Operatire Chh'urgie. Berlin 1943, p. 711. 13. OBWEGESER,H. L.: The surgical correction of mandibular prognathism and retrognathia with consideration of gonioplasty. Oral Surg. 1957: 10: 677-689. 14. OBWEGESER, t-I. L.: The indications for surgical correction of mandibular deformity by the sagittal splitting technique. Br. J. Oral Surg. 1963: 1: 157-171. ]5. PERTHES, G.: Operative Korrektur der Progenie. Zbl. Chir. I922: 49: 1540-1541. 16. RaI-IRMANN, A.: Osteoplastische Verriegelung des Kiefergelenks in Fg.llen yon habitueller Luxation. Zbl, Chlr. 1956: 81: 521531. 17. REHR~ANN,A.: Horizontale Osteotomie der Unterkieferaeste mit Drahtnaht zur Behebung der Progenie mit Erhaltung der urspruenglichen Position der Gelenkkoepfe. Dtsch. Zahn-, Mund-, Kieferheilkd. 1967: 49: 72-76. 18. REHRMANN,A. & KREIDLER, J.: Late results after arthroereisis of the temporomandibufar joint by autop]astic bone graft. 1. Maxitlo/ac. Surg. 1973: 1: 99-11)3. 19. REICHENBACH, E., KOELE, H. & BRUECKL, H.: Chirurgische Kie/erorthopaedie. Johann Ambrosius Barth, Leipzig 1970, p. 17-123. 20. ROWE, N. L.: The etiology, clinical features and treatment of mandibular deformity. Br. Dent. J. 1960: 108: 45-64. 21. TRAUNER, R. & OBWEGESEP,, H.: Zur Operationstechnik bei der Progenie und andeten Unterkieferanomalien. Dtsch. Zahn-, Mund-, Kie/erheilkd. 1955: 23: 1-26.