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Surgical correction of anterior open bite
lilt. J. Oral Sllrg. 1978: 7: 286-288 (Key words: slIrgery, art/lOgllathie; opell bite; deformities, jaws)
Surgical correction of anterior open bite J. R. HAYWARD University Hospital, Medical Center, An/! Arbor, Michigan, U.S.A.
Classification and quantitation are significant in describing the anomalies corrected by orthognathic surgery3,B. Anterior open bite is not common but is a challenging problem to both orthodontist and surgeon 7 ,9. In addition to the vertical gap between the anterior teeth, the gonial angle is characteristically obtuse; there is downward bending at the antegonial notch; and the mandibular-maxillary plane angle is very high in classic cases10 • The ramus usually is short in the more micrognathic cases, but occasionally the ramus will be long where prognathism is featured along with anterior open bite. The maxillary anterior teeth may be elevated to distort the occlusal plane and accentuate the gap in some varieties. The causes for anterior open bite appear to be: inherent skeletal development, muscle and other soft tissue imbalances, as well as habit patterns 2 ,4. The role of each of these variables, as well as the tongue and the suprahyoid musculature, have received a great deal of attention1 • The tongue in size, suspension, and thrusting functions has challenged our clinical observationo. The tongue contour adapts to, the variables in the mouth and on the other hand, dentoalveolar structures are molded and adapt to the tongue. The only criterion used in our small series for the perfm-mance of
partial glossectomy was the finding of a flaccid tongue which protruded out and could not be confined within the mouth when the patient was under general anesthesia. Whatever their degree and number, the factors causing the condition of anterior open bite represent a threat of relapse, whether treatment is orthodontic or surgical. The unstable orthodontic corrections and the root resorption from traction on teeth have discouraged this form of therapy for the problem. In the series studied, the stability of longterm surgical corrections was observed in the 12 cases corrected by segmental procedures of KOLE 5 and SCHUCHARDT as well as ramus and body osteotomies occasionally combined with anterior maxillary Wassman osteotomy. The spectrum of variables illustrated by these cases is summarized in Table 1. In a fairly rare condition caused by many factors which are operable at different stages in development and with many individual variables in adaptation and healing, it is quite impossible to attempt any terminal judgments on a particular corrective procedure. The conclusions, at best, can only suggest a tendency for greater or lesser degrees of stability. Stability must have a high priority in our treatment planning
SURGICAL CORRECTION OF ANTERIOR OPEN BITE
287
Table 1. Case data on 12 patients with anterior open bite
Patient
Age at surgery
1 2 3
28 18 19 18
5 6
19 16 30 21 17 34 23
4
7
8 9 10 11
12
18
Procedure VRO K+PGl K Sagittal split body K VRO VRO K Schu.+ B K+W K+W PGl K
Previous orthodontics
Max.-mand. plane angle
Open bite, mm
1 year 6 years 2% years 3 years
46° 43° 38° 60°
6 12 8 12
4 years 3 years pre 2 years
36° 36°
7
36° 39° 42° 40° 39° 34°
7 10
0 0 0
1 year
0
3 years
5
11
6
10
6
Follow-up, years 8 6 4
Relapse, mm
3
0 1 0 6
3% 3%
0 0
3V2 2% 2 1 1 1
1 0 0 1 1 0
Anterior open bite operations: VRO, ramus osteotomy. B, body osteotomy. K, KOle segmental osteotomy. W, Wassmund maxillary osteotomy. Schu., Schuchardt maxillary osteotomy. PGI, partial glossectomy.
and even the trend lines from clinical experiences may be useful. The suggested phenomena are: 1) greatest stability was observed in the anterior segmental procedures of KaLE; 2) the least stable result involved sectioning at the midbody region of the mandible; 3) when prognathism was a feature with a long ramus, correction at that site was stable if the coronoid process is sectioned. 4) if posterior maxillary height was a significant correlated feature, then the posterior maxillary intmsion of SCHUCHARDT was useful; 5) anterior segmental maxillary dropping (WUNDERER) without bone graft had a tendency to relapse with elevation and mild recurrence of anterior opening;
6) all the patients on long-term follow-up
were improved and appreciated the functional, aesthetic and psychological self-image improvements gained by the surgery.
References 1. ANDERSON, W.: The relationship of the
2. 3. 4.
S.
tongue thrust syndrome to maturation and other factors. Am. 1. Orthod. 1963: 49: 264. GRABER, T. M.: The "Three M's": Muscles, malformation and malocclusion. Am. J. Orthod. 1963: 49: 418. HINDS, E. C. & KENT, J. N.: Surgical treatment of developmental jaw deformation. C. V. Mosby, St. Louis 1972, p. 152. HOVELL, J.: Aetiology and development of open bite. In: WALKER, R. V. (ed.): Trans. 3rd Int. Coni. Oral Surgery, New York 1968. KOLE, H.: Results, experience and problems
288
6.
7. 8. 9.
HAYWARD in the operative treatment of anomalies with severe open bite. Oral Surg. 1965: 19: 427. KYDD, W. L., AKAMINE, J. S., MENDEL, R. A. & KRAus, B. S.: Tongue and lip forces exerted during deglutition in subjects with and without anterior open bite. J. Dent. Res. 1963: 42: 858. NEFF, C. W. & KYDD, W. L.: Open bite physiology and occlusion. Angle Orthod. 1966: 66: 351. SASSOUNI, V. & NANDA, S.: Analysis of dentofacial vertical proportions. Am. J. Orthod. 1964: 50: 801. SHIRA, R. B. & ALLING, C. c.: Mandibular surgery for correction of open bite. In:
WALKER, R. V. (ed.): Trans. 3rd lnt. Conf. Oral Surgery, New York 1968. 10. SILBERMANN, M., MOYNIHAN, F. M., MALON:EY, P. L., F'ERULLIO, R. J. & DOKU, H. C.: Skeletal open bite associated with maxillary dentoalveolar protrusion, evaluation and treatment. Br. J. Oral Surg. 1972: 10: 227. Address: University Hospital University of Michigan Medical Center All/I Arbor Michigan 48104 U.S.A.
Surgical correction of anterior open bite J. R. HAYWARD University Hospital, Medical Center, An/! Arbor, Michigan, U.S.A.
Classification and quantitation are significant in describing the anomalies corrected by orthognathic surgery3,B. Anterior open bite is not common but is a challenging problem to both orthodontist and surgeon 7 ,9. In addition to the vertical gap between the anterior teeth, the gonial angle is characteristically obtuse; there is downward bending at the antegonial notch; and the mandibular-maxillary plane angle is very high in classic cases10 • The ramus usually is short in the more micrognathic cases, but occasionally the ramus will be long where prognathism is featured along with anterior open bite. The maxillary anterior teeth may be elevated to distort the occlusal plane and accentuate the gap in some varieties. The causes for anterior open bite appear to be: inherent skeletal development, muscle and other soft tissue imbalances, as well as habit patterns 2 ,4. The role of each of these variables, as well as the tongue and the suprahyoid musculature, have received a great deal of attention1 • The tongue in size, suspension, and thrusting functions has challenged our clinical observationo. The tongue contour adapts to, the variables in the mouth and on the other hand, dentoalveolar structures are molded and adapt to the tongue. The only criterion used in our small series for the perfm-mance of
partial glossectomy was the finding of a flaccid tongue which protruded out and could not be confined within the mouth when the patient was under general anesthesia. Whatever their degree and number, the factors causing the condition of anterior open bite represent a threat of relapse, whether treatment is orthodontic or surgical. The unstable orthodontic corrections and the root resorption from traction on teeth have discouraged this form of therapy for the problem. In the series studied, the stability of longterm surgical corrections was observed in the 12 cases corrected by segmental procedures of KOLE 5 and SCHUCHARDT as well as ramus and body osteotomies occasionally combined with anterior maxillary Wassman osteotomy. The spectrum of variables illustrated by these cases is summarized in Table 1. In a fairly rare condition caused by many factors which are operable at different stages in development and with many individual variables in adaptation and healing, it is quite impossible to attempt any terminal judgments on a particular corrective procedure. The conclusions, at best, can only suggest a tendency for greater or lesser degrees of stability. Stability must have a high priority in our treatment planning
SURGICAL CORRECTION OF ANTERIOR OPEN BITE
287
Table 1. Case data on 12 patients with anterior open bite
Patient
Age at surgery
1 2 3
28 18 19 18
5 6
19 16 30 21 17 34 23
4
7
8 9 10 11
12
18
Procedure VRO K+PGl K Sagittal split body K VRO VRO K Schu.+ B K+W K+W PGl K
Previous orthodontics
Max.-mand. plane angle
Open bite, mm
1 year 6 years 2% years 3 years
46° 43° 38° 60°
6 12 8 12
4 years 3 years pre 2 years
36° 36°
7
36° 39° 42° 40° 39° 34°
7 10
0 0 0
1 year
0
3 years
5
11
6
10
6
Follow-up, years 8 6 4
Relapse, mm
3
0 1 0 6
3% 3%
0 0
3V2 2% 2 1 1 1
1 0 0 1 1 0
Anterior open bite operations: VRO, ramus osteotomy. B, body osteotomy. K, KOle segmental osteotomy. W, Wassmund maxillary osteotomy. Schu., Schuchardt maxillary osteotomy. PGI, partial glossectomy.
and even the trend lines from clinical experiences may be useful. The suggested phenomena are: 1) greatest stability was observed in the anterior segmental procedures of KaLE; 2) the least stable result involved sectioning at the midbody region of the mandible; 3) when prognathism was a feature with a long ramus, correction at that site was stable if the coronoid process is sectioned. 4) if posterior maxillary height was a significant correlated feature, then the posterior maxillary intmsion of SCHUCHARDT was useful; 5) anterior segmental maxillary dropping (WUNDERER) without bone graft had a tendency to relapse with elevation and mild recurrence of anterior opening;
6) all the patients on long-term follow-up
were improved and appreciated the functional, aesthetic and psychological self-image improvements gained by the surgery.
References 1. ANDERSON, W.: The relationship of the
2. 3. 4.
S.
tongue thrust syndrome to maturation and other factors. Am. 1. Orthod. 1963: 49: 264. GRABER, T. M.: The "Three M's": Muscles, malformation and malocclusion. Am. J. Orthod. 1963: 49: 418. HINDS, E. C. & KENT, J. N.: Surgical treatment of developmental jaw deformation. C. V. Mosby, St. Louis 1972, p. 152. HOVELL, J.: Aetiology and development of open bite. In: WALKER, R. V. (ed.): Trans. 3rd Int. Coni. Oral Surgery, New York 1968. KOLE, H.: Results, experience and problems
288
6.
7. 8. 9.
HAYWARD in the operative treatment of anomalies with severe open bite. Oral Surg. 1965: 19: 427. KYDD, W. L., AKAMINE, J. S., MENDEL, R. A. & KRAus, B. S.: Tongue and lip forces exerted during deglutition in subjects with and without anterior open bite. J. Dent. Res. 1963: 42: 858. NEFF, C. W. & KYDD, W. L.: Open bite physiology and occlusion. Angle Orthod. 1966: 66: 351. SASSOUNI, V. & NANDA, S.: Analysis of dentofacial vertical proportions. Am. J. Orthod. 1964: 50: 801. SHIRA, R. B. & ALLING, C. c.: Mandibular surgery for correction of open bite. In:
WALKER, R. V. (ed.): Trans. 3rd lnt. Conf. Oral Surgery, New York 1968. 10. SILBERMANN, M., MOYNIHAN, F. M., MALON:EY, P. L., F'ERULLIO, R. J. & DOKU, H. C.: Skeletal open bite associated with maxillary dentoalveolar protrusion, evaluation and treatment. Br. J. Oral Surg. 1972: 10: 227. Address: University Hospital University of Michigan Medical Center All/I Arbor Michigan 48104 U.S.A.