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Simianism: Surgical-orthodontic correction of bimaxillary protrusion
8
J.M. Converse, S. L. Horowitz
Suturing of the periosteum is of course more difficult than through the infra orbital incision. It is rendered easier by m a k i n g a r e l a x i n g incision in the periosteum at the lowest point of the dissection or when the periosteum has been cut at this point by a vestibular dissection. Long eonjunctival incisions extending behind the lateral eanthus require a conformer for preventing atresia of the fornix.
Conclusions T h e conjunctival approach has proven to be very useful for exposure of the orbital floor and of the inferior portions of the lateral and medial orbital wails without the necessity of a skin incision. The conjunctival approach does not however completely eliminate the infra-orbital incision, even if the scars are not negligible in certain cases. Paul Tessier, M.D., 26 Av. Klgber, Paris 16e, France
J. max.-fac. Surg. 1 (1973) 8-12 @ Georg Thieme Verlag, Stuttgart
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion John M. ConversO, S. L. Horowitz~
Summary The authors describe a case of bimaxillary protrusion characterized by a simian-type mandible. To this syndrome they have given the name: Simianism. - The various stages of the combined surgical and orthodontic treatment are described. A successful functional and esthetic result was obtained, the patient last being observed four years after the completion of treatment. Short-cuts in the treatment could have been taken as our own retrospective analysis suggested. The unusual aspects of the deformity prompted a slower and more prudent approach. - The conclusion of the authors is that the combined skills of the surgeon and the orthodontist are necessary to obtain the most adequate results in such cases.
Key-Words: Bimaxillary protrusion, orthodontic surgery. J Lawrence D. Bell, Professor of Plastic Surgery, New York University School of Medicine and Director, Institute of Reconstructive Plastic Surgery, New York University Medical Center. Formerly Associate Director in charge of Cleft Palate Program, Institute of Reconstructive Plastic Surgery, New York University Medical Center; presently Pro-. lessor of Dentistry and Director of the Division of Orofacial Development, Columbia University School of Dental and Oral Surgery.
Introduction T h e face of m o d e r n man is distinguished from his early forebears and living primate relatives by reduction in the f o r w a r d projection of the jaws. Relative protrusion of the snout is seen in all simians but only r a r e l y in humans (particularly whites) and even then is usually confined to either the lower j a w (mandibular prognathism) or m a x i l l a (skeletal Class I I - A n g l e occlusion). In the case reported here, bimaxillary protrusion (simianism) caused a severe and unusual facial deformity in a 21-year-old white female (Fig. I a). The patient's mandible and dento-alveolar arch show an elongated shape with contraction of the horizontal dimension (Fig. 2a) reminiscent of the jaw of the primate (Fig. 2b) and a simian bony shelf which could be felt by digital palpation, immediately behind the incisor area. Several factors were considered in planning the total corrective program for this patient. These were: (a) the increased skeletal facial height, as shown in the cephalometric tracing (Fig. 3a), and also demonstrated by the location of the chin pad above the mental symphysis seen in the frontal photograph (Fig. la); (b) dental malocclusion (Class I) with severe crowding (Fig. 2b); and (c) prognathism of both the upper and
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion
9
Fig. 1 a Appearance of the patient who consulted us because of her concern that she was being nicknamed "monkey face". Note the considerable increase in facial height. Fig. 1 b Postoperative photograph of the patient after completion of treatment.
Fig. 1 c Profile view showing bimaxillary prognathism. Fig. 1 d Profile view of the patient following surgicalorthodontic treatment.
lower dcnto-alveolar areas in relation to other facial structures. In planning the treatment of this patient, the principal objectives were to diminish facial height and to reduce the bimaxillary prognathism. Several staged procedures were used to accomplish these goals. Stage 1. The first operation consisted of a reduction i~a the vertical dimension of the body of the mandible by the resection of a predetermined portion of the mandible along its inferior border, and transplantation of the resected segment of bone to a point anterior to the mental syrnphysis. This procedure has been employed successfully by us since 1953 in eases in which the height of the mandibular body requires reduction and when increased projection of the chin point is indicated. The
resected segment was adapted to the contour of the mandible by burring the cortex of its posterior surface until the horseshoe-shaped graft accurately fitted to the host bed (Fig. 4). The approach in these procedures is routinely done through an intra-oral incision followed by subperiosteal elevation of the periosteum, degloving the anterior portion of the mandible and preserving the mental nerve branches. Muscles attached to the sectioned segment of bone are detached subperiosteally. After the placement of the resected bone, without wire fixation, the incision through mucous membrane is sutured with plain catgut sutures. A carefully adapted dressing is placed to immobilize the graft and to eliminate dead space in which hematoma might accumulate. The dressing con-
10
]. M, Converse, S. L. Horowitz
Fig. 2a Note the elongated shape of the patient's mandible with restriction in the horizontal dimension reminiscent of the jaw of a primate (b).
Fig. 3a Cephalometric tracing prior to treatment showing the increased skeletal facial height. Fig. 3b Cephalometric tracing taken four years following completion of treatment showing changes in the dento-alveolar relationships, diminution in facial height and adequate protrusion of the mental symphysis (see also Fig. 1 d).
Fig. 4 Photograph of the resected segment from the antero-inferior portion of the mandible after exposure by the "degloving" procedure, The cortex of the posterior aspect of the bone is being burred in order to establish close contact between the horseshoe-shaped graft and the underlying bone.
sists of strips of elastoplast reinforced by plain adhesive tape. The dressing is maintained for a period of six days following which consolidation of the graft to the underlying host bed has already begun. The procedure provides both shortening of the total face height and adequate protrusion of the mental symphysis area. As can be observed on the cephalometric tracing of the patient four years following the procedure, a satisfactory contour was maintained (Fig. 3b). Stage 2. Orthodontic treatment to relieve the severe dental crowding and to reduce the protrusion of the maxillary and mandibular dento-alveolar area comprised the second stage of treatment. This required extraction of both the maxillary and the mandibular first premolar teeth. The spaces thus made availahle were
used to realign the anterior teeth and to retract them as much as possible using upper and lower edgewise arch orthodontic appliances over a period of approximately one year (Figs. 5a and b, 6a and b). Since much of the extraction space was required for tooth realignment (particularly in the mandibular dental arch), both the upper and lower dento-alveolar areas were still relatively prognathic following orthodontic therapy. In order to correct this disharmony, a combined surgicalorthodontic approach was planned to correct the remaining bimaxillary prognathism. Stage 3. In the third phase, mandibular second premolars were extracted (Fig. 5a), the dento-alveolar process was exposed subperiosteally, and an alveolar set-ha& osteotomy was performed below the level of the apices
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion
A
C
B
A
/
U
C
11
D
I
.~J~~7~A
Fig. 5a Drawing made from the cast showing the original dental malatignment of the mandibular teeth. The arrows indicate the extraction of first premolar teeth, Fig. 5b Result obtained following orthodontic therapy. Fig. 5c Drawing made from the cast showing the contour of the mandibular dento-alveolar arch following orthodontic therapy. The arrows indicate the extraction of the second premolar teeth prior to a dento-alveolar set-back procedure (Fig. 7). Fig, 5d Contour of the mandibular arch following the set-back osteotomy.
Fig. 7 Diagram illustrates the technique of the dento-alveolar set-back osteotomy.
of the teeth (Fig. 7). The dento-alveolar biock was moved posteriorly virtually the entire width of the extraction space (Fig. 5b), temporarily creating a horizontal overjet of nearly 1 cm. between the upper and lower anterior teeth. The edgewise arch orthodontic appliance was used for fixation. Stage 4. In order to harmonize the occlusion and complete the reduction of the bimaxillary prognathism, the
_/
Fig, 6a Drawing of the maxillary arch prior to treatment. The arrows indicate extraction of the first premolar teeth. Fig. 6b Contour of the arch following orthodontic therapy. Fig. 6c The arrows indicate the extraction of the second premolar teeth. Fig. 6d Contour of the maxillary arch following the dento-alveolar set-back osteotomy (Fig. 7).
t
upper second premolars were then removed (Fig. 6c) and the anterior portion of the maxilla containing the six anterior maxillary teeth and dento-alveolar bone moved ba&wards (Fig. 6d) by means of a maxillary premolar segmental set-ba& osteotomy, with fixation provided by the edgewise arch orthodontic appliance after resection of the appropriate amount of bone from the hard palate.
12
]. M. Converse, S. L. Horowitz: Simianism: Surgical-Orthodontic Correction
Fig. 8a Lateral view of the dental casts in occlusion at the start of treatment,
Fig. 8b View of the casts at the completion of treatment.
Fig. 9a Occlusal view of the mandibular dental cast prior to treatment. Fig. 9 b View at the conclusion of treatment.
Fig. lOa Occlusal view of maxillary dental arch prior to treatment. Fig, lOb View following completion of treatment.
Fig. 11 Pre- and postoperative cephalographic tracings superimposed showing the changes in the dentition and facial form, The shaded area shows the preoperative contour.
Discussion
As seen from the photographs of the dental casts (Figs. 8, 9 and 10), the combination of orthodontic alignment and orthodontic-surgical set-ba& of the anterior dental alveolar segments resulted in considerable improvement in the general contour of the dental arches which are now parabolic rather than simian in form. Removal of the eight premolar teeth permitted foreshortening of the dental arches, without loss of dental arch continuity, and reduction of the bimaxillary prognathism. It is unlikely that this amount of arch shortening could have been obtained through orthodontic treatment, and it is certain that the improved tooth
alignment could not have been obtained through surgical procedures alone. A combined orthodontic~ w a s required. Y ~ f treatment could have been shortened by combining Stages 3 and 4 through careful predetermination of the desired position of the dento-alveolar segments and concomitant maxillary and mandibular dento-alveolar osteotomies. Because the case was an unusual one, we were obliged to feel our way in the treatment of this patient, and the finaI result was a satisfactory one (Fig. 1, Fig. 11). John M. Converse, M.D., S. L. Horowitz, D.D.S., Inst. of Reconstructive Plastic Surgery, New York Univ. Med. Center, ,:,60 First Avenue, New York, N . Y . 10016
J.M. Converse, S. L. Horowitz
Suturing of the periosteum is of course more difficult than through the infra orbital incision. It is rendered easier by m a k i n g a r e l a x i n g incision in the periosteum at the lowest point of the dissection or when the periosteum has been cut at this point by a vestibular dissection. Long eonjunctival incisions extending behind the lateral eanthus require a conformer for preventing atresia of the fornix.
Conclusions T h e conjunctival approach has proven to be very useful for exposure of the orbital floor and of the inferior portions of the lateral and medial orbital wails without the necessity of a skin incision. The conjunctival approach does not however completely eliminate the infra-orbital incision, even if the scars are not negligible in certain cases. Paul Tessier, M.D., 26 Av. Klgber, Paris 16e, France
J. max.-fac. Surg. 1 (1973) 8-12 @ Georg Thieme Verlag, Stuttgart
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion John M. ConversO, S. L. Horowitz~
Summary The authors describe a case of bimaxillary protrusion characterized by a simian-type mandible. To this syndrome they have given the name: Simianism. - The various stages of the combined surgical and orthodontic treatment are described. A successful functional and esthetic result was obtained, the patient last being observed four years after the completion of treatment. Short-cuts in the treatment could have been taken as our own retrospective analysis suggested. The unusual aspects of the deformity prompted a slower and more prudent approach. - The conclusion of the authors is that the combined skills of the surgeon and the orthodontist are necessary to obtain the most adequate results in such cases.
Key-Words: Bimaxillary protrusion, orthodontic surgery. J Lawrence D. Bell, Professor of Plastic Surgery, New York University School of Medicine and Director, Institute of Reconstructive Plastic Surgery, New York University Medical Center. Formerly Associate Director in charge of Cleft Palate Program, Institute of Reconstructive Plastic Surgery, New York University Medical Center; presently Pro-. lessor of Dentistry and Director of the Division of Orofacial Development, Columbia University School of Dental and Oral Surgery.
Introduction T h e face of m o d e r n man is distinguished from his early forebears and living primate relatives by reduction in the f o r w a r d projection of the jaws. Relative protrusion of the snout is seen in all simians but only r a r e l y in humans (particularly whites) and even then is usually confined to either the lower j a w (mandibular prognathism) or m a x i l l a (skeletal Class I I - A n g l e occlusion). In the case reported here, bimaxillary protrusion (simianism) caused a severe and unusual facial deformity in a 21-year-old white female (Fig. I a). The patient's mandible and dento-alveolar arch show an elongated shape with contraction of the horizontal dimension (Fig. 2a) reminiscent of the jaw of the primate (Fig. 2b) and a simian bony shelf which could be felt by digital palpation, immediately behind the incisor area. Several factors were considered in planning the total corrective program for this patient. These were: (a) the increased skeletal facial height, as shown in the cephalometric tracing (Fig. 3a), and also demonstrated by the location of the chin pad above the mental symphysis seen in the frontal photograph (Fig. la); (b) dental malocclusion (Class I) with severe crowding (Fig. 2b); and (c) prognathism of both the upper and
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion
9
Fig. 1 a Appearance of the patient who consulted us because of her concern that she was being nicknamed "monkey face". Note the considerable increase in facial height. Fig. 1 b Postoperative photograph of the patient after completion of treatment.
Fig. 1 c Profile view showing bimaxillary prognathism. Fig. 1 d Profile view of the patient following surgicalorthodontic treatment.
lower dcnto-alveolar areas in relation to other facial structures. In planning the treatment of this patient, the principal objectives were to diminish facial height and to reduce the bimaxillary prognathism. Several staged procedures were used to accomplish these goals. Stage 1. The first operation consisted of a reduction i~a the vertical dimension of the body of the mandible by the resection of a predetermined portion of the mandible along its inferior border, and transplantation of the resected segment of bone to a point anterior to the mental syrnphysis. This procedure has been employed successfully by us since 1953 in eases in which the height of the mandibular body requires reduction and when increased projection of the chin point is indicated. The
resected segment was adapted to the contour of the mandible by burring the cortex of its posterior surface until the horseshoe-shaped graft accurately fitted to the host bed (Fig. 4). The approach in these procedures is routinely done through an intra-oral incision followed by subperiosteal elevation of the periosteum, degloving the anterior portion of the mandible and preserving the mental nerve branches. Muscles attached to the sectioned segment of bone are detached subperiosteally. After the placement of the resected bone, without wire fixation, the incision through mucous membrane is sutured with plain catgut sutures. A carefully adapted dressing is placed to immobilize the graft and to eliminate dead space in which hematoma might accumulate. The dressing con-
10
]. M, Converse, S. L. Horowitz
Fig. 2a Note the elongated shape of the patient's mandible with restriction in the horizontal dimension reminiscent of the jaw of a primate (b).
Fig. 3a Cephalometric tracing prior to treatment showing the increased skeletal facial height. Fig. 3b Cephalometric tracing taken four years following completion of treatment showing changes in the dento-alveolar relationships, diminution in facial height and adequate protrusion of the mental symphysis (see also Fig. 1 d).
Fig. 4 Photograph of the resected segment from the antero-inferior portion of the mandible after exposure by the "degloving" procedure, The cortex of the posterior aspect of the bone is being burred in order to establish close contact between the horseshoe-shaped graft and the underlying bone.
sists of strips of elastoplast reinforced by plain adhesive tape. The dressing is maintained for a period of six days following which consolidation of the graft to the underlying host bed has already begun. The procedure provides both shortening of the total face height and adequate protrusion of the mental symphysis area. As can be observed on the cephalometric tracing of the patient four years following the procedure, a satisfactory contour was maintained (Fig. 3b). Stage 2. Orthodontic treatment to relieve the severe dental crowding and to reduce the protrusion of the maxillary and mandibular dento-alveolar area comprised the second stage of treatment. This required extraction of both the maxillary and the mandibular first premolar teeth. The spaces thus made availahle were
used to realign the anterior teeth and to retract them as much as possible using upper and lower edgewise arch orthodontic appliances over a period of approximately one year (Figs. 5a and b, 6a and b). Since much of the extraction space was required for tooth realignment (particularly in the mandibular dental arch), both the upper and lower dento-alveolar areas were still relatively prognathic following orthodontic therapy. In order to correct this disharmony, a combined surgicalorthodontic approach was planned to correct the remaining bimaxillary prognathism. Stage 3. In the third phase, mandibular second premolars were extracted (Fig. 5a), the dento-alveolar process was exposed subperiosteally, and an alveolar set-ha& osteotomy was performed below the level of the apices
Simianism: Surgical-Orthodontic Correction of Bimaxillary Protrusion
A
C
B
A
/
U
C
11
D
I
.~J~~7~A
Fig. 5a Drawing made from the cast showing the original dental malatignment of the mandibular teeth. The arrows indicate the extraction of first premolar teeth, Fig. 5b Result obtained following orthodontic therapy. Fig. 5c Drawing made from the cast showing the contour of the mandibular dento-alveolar arch following orthodontic therapy. The arrows indicate the extraction of the second premolar teeth prior to a dento-alveolar set-back procedure (Fig. 7). Fig, 5d Contour of the mandibular arch following the set-back osteotomy.
Fig. 7 Diagram illustrates the technique of the dento-alveolar set-back osteotomy.
of the teeth (Fig. 7). The dento-alveolar biock was moved posteriorly virtually the entire width of the extraction space (Fig. 5b), temporarily creating a horizontal overjet of nearly 1 cm. between the upper and lower anterior teeth. The edgewise arch orthodontic appliance was used for fixation. Stage 4. In order to harmonize the occlusion and complete the reduction of the bimaxillary prognathism, the
_/
Fig, 6a Drawing of the maxillary arch prior to treatment. The arrows indicate extraction of the first premolar teeth. Fig. 6b Contour of the arch following orthodontic therapy. Fig. 6c The arrows indicate the extraction of the second premolar teeth. Fig. 6d Contour of the maxillary arch following the dento-alveolar set-back osteotomy (Fig. 7).
t
upper second premolars were then removed (Fig. 6c) and the anterior portion of the maxilla containing the six anterior maxillary teeth and dento-alveolar bone moved ba&wards (Fig. 6d) by means of a maxillary premolar segmental set-ba& osteotomy, with fixation provided by the edgewise arch orthodontic appliance after resection of the appropriate amount of bone from the hard palate.
12
]. M. Converse, S. L. Horowitz: Simianism: Surgical-Orthodontic Correction
Fig. 8a Lateral view of the dental casts in occlusion at the start of treatment,
Fig. 8b View of the casts at the completion of treatment.
Fig. 9a Occlusal view of the mandibular dental cast prior to treatment. Fig. 9 b View at the conclusion of treatment.
Fig. lOa Occlusal view of maxillary dental arch prior to treatment. Fig, lOb View following completion of treatment.
Fig. 11 Pre- and postoperative cephalographic tracings superimposed showing the changes in the dentition and facial form, The shaded area shows the preoperative contour.
Discussion
As seen from the photographs of the dental casts (Figs. 8, 9 and 10), the combination of orthodontic alignment and orthodontic-surgical set-ba& of the anterior dental alveolar segments resulted in considerable improvement in the general contour of the dental arches which are now parabolic rather than simian in form. Removal of the eight premolar teeth permitted foreshortening of the dental arches, without loss of dental arch continuity, and reduction of the bimaxillary prognathism. It is unlikely that this amount of arch shortening could have been obtained through orthodontic treatment, and it is certain that the improved tooth
alignment could not have been obtained through surgical procedures alone. A combined orthodontic~ w a s required. Y ~ f treatment could have been shortened by combining Stages 3 and 4 through careful predetermination of the desired position of the dento-alveolar segments and concomitant maxillary and mandibular dento-alveolar osteotomies. Because the case was an unusual one, we were obliged to feel our way in the treatment of this patient, and the finaI result was a satisfactory one (Fig. 1, Fig. 11). John M. Converse, M.D., S. L. Horowitz, D.D.S., Inst. of Reconstructive Plastic Surgery, New York Univ. Med. Center, ,:,60 First Avenue, New York, N . Y . 10016