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Surgical correction of bimaxillary protrusion and mandibular retrusion
Oral SURGERY Oral MEDICINE AND
Oral PATH 0 LO GY
VOLUME
30
NUMBER
1
JULY,
1970
Operative oral surgery
Surgical correction of bimaxillary protrusion and mandibular retrusion Bernard $1. Lyons, D.D.S., Galveston, Texas UNIVERSITY
OF TEXAS
MEDICAL
BRANCH
F
unctional and esthetic correction of a severely retruded mandible is one of the most difficult and challenging problems of the orthodontist and oral surgeon. The present article will describe the surgical correction of a severe Angle Class II occlusion. This patient was referred to the Division of Oral and Maxillofacial Surgery at the University of Texas Medical Branch from the Division of Orthopedic Surgery. It was the opinion of the consulting orthodontist that this patient would be best treated surgically. Orthodontic therapy could be delayed until a more favorable position of the mandibular and maxillary arches was attained. CASE REPORT A 16-year-old white boy, in good physical condition, had a history of severe scoliosis of both the dorsal and lumbar spine. He had worn a Milwaukee brace for the past 2 years (Fig. l), and 1 year ago had undergone a fusion of the fourth and fifth lumbar and first sacral vertebrae. The patient’s mother stated that prior to his wearing of the Milwaukee brace he had an “underbite.” However, because of the patient’s habit of resting his chin posterior to, instead of superior to, the chin portion of the Milwaukee brace, this “underbite” appeared to become more severe. Examination
and
preliminary
procedures
Physical examination revealed the patient had a right scoliosis of the dorsal and lumbar spine with a surgical scar in the area of the fourth and fifth lumbar and first sacral vertebrae. There was a maxillary overjet of 18 mm. and an overbite of 12 mm. (Figs. 2, 3, a&
1
2
Lyons
Oral Burg. July, 1970
4). The anterior maxillary teeth rested on the lower lip, and the lip had a tendency to curl downward. The upper lip appeared short, giving the anterior maxillary teeth a protrusive appearance. The lower anterior teeth had overerupted and were in contact with the soft tissue of the palate 7 mm. proximal to the lingual gingiva of the anterior maxillary teeth. The patient had numerous emotional and motivational problems, and there was a history of noncooperation with the orthodontist and orthopedic surgeons. A consultation with the Department of Psychiatry revealed that the patient had a reasonable and realistic attitude toward the propose’d surgical procedure and toward the problems of the postoperative convalescence period. The psychiatrist did not anticipate problems in management, and it was decided to go ahead with the surgical procedure. Panoramic and skull roentgenograms were taken, and a series of maxillary and mandibular study models were constructed. These study models underwent numerous sectionings and reassemblings until a desirable functional and esthetic result was achieved. The combination of maxillary protrusion and mandibular retrusion required surgical correction in both the maxilla and the mandible. It was decided that the correction would be done in two stages. The initial surgical procedure would involve a maxillary osteotomy with removal of the two first bicuspids and a posterior “set-back” of the anterior segment of approximately 10 mm. After a sufficient healing period, the second operative procedure, consisting of a mandibular osteotomy, with an iliac ‘bone graft to fill the defects created, would be performed.
Volume 30 Number 1
Bimaxillary
protrusion
and mandibular
retrusion
3
Prior to the patient’s admission to the hospital, Stout intramaxillary multiple loop wires were placed on the posterior teeth. An acrylic splint was fabricated which would allow positioning of the anterior maxilla 10 mm. proximal to the existing position. These preliminary measures reduced the time normally required for such an operation. Operative
course
The patient was placed on the operating table in a supine position. Following suitable nasotraeheal intubation, he was prepared and draped in the usual manner. A subperiosteal flap was elevated on the buccal surface of each first premolar. A 2 cm. midline incision was made in the palate, and the maxillary first premolars were removed. A tunnel was created from the lingual surfaces of the maxillary first premolars to the area of the vertical palatal incision. Bone was removed from the labial, lingual, and palatal areas in the region of the maxillary first premolars. An incision was then made in the area of the anterior nasal spine. A subperiosteal tunnel was created in the area of the mucobuccal fold along the buccal plate of bone to join the flap over the buceal surfaces of the first premolar-s. A mallet and osteotome were used to section this outer cortex, which completely freed the anterior
P
Fig.
6
F
4
Oral Surg. July, 1970
Lyons
maxillary segment. The segment was set back to the point where the distal surface of the cuspids contacted the mesial sarfaces of the second premolars. The prefabricated acrylic splint was inserted. The anterior segment was properly aligned and held in position adjacent to the posterior segments. Ivy loops were placed on the upper and lower anterior segments to aid in immobilization. The mandibular arch was then positioned into the undersurface of the splint, and the jaws were immobilized with intermaxillary elastic fixation. The soft-tissue flaps were approximated and sutured with 3-O chromic sutures. Blood loss was estimated at 400 C.C. There was no blood replacement, and fluid replacement consisted of 1,000 C.C. of lactated Ringer’s solution. No drains were used. The patient tolerated the procedure well. Postoperative
cows*
Following an uneventful recovery, the patient was discharged from the hospital on the eleventh postoperative day. After 7 weeks of inter-maxillary fixation, the acrylic splint and the intramaxillary wires were removed. The fragments were then retained in proper position with a Hawley type of orthodontic retainer (Fig. 5). This was necessary because the overerupted mandibular anterior teeth now occluded prematurely into the palate, and the resulting trauma would have prevented proper bony union. Two months later the patient was readmitted to the hospital for the second stage of correction of the mandibular retrusion and maxillary protrusion. Prior to readmission, Stout intramaxillary multiple loop wires were again placed and a new acrylic splint was fabricated. The patient required correction of an 8 mm. overjet and a 12 mm. overbite. It was determined that a satisfactory result could be achieved by movement of the anterior mandible into a downward position with forward rotation (Fig. 6). The study models had been sectioned and reassembled in various planes until a desirable functional and esthetic result was obtained. Numerous paper tracings and “cut-outs” had been made to determine the proper position of the mandibular fragments (Fig. 7). The plan was to perform a bilateral osteotomy of the mandibular body in the region of the first premolars. The anterior segment would be rotated to a downward and forward position and the defect obliterated by means of an iliac bone graft. The tracings had revealed that the face would be excessively long after the planned repositioning of the anterior mandibular segment. It was therefore decided that a reduction in the length of the chin (Fig. 7), followed by placement of the excised bone on the anterior surface of the mandible, would both decrease the excessive length of the face and provide a more esthetic result. Operative
course
Following adequate nasotracheal intubation, the face and left hip were prepared in the customary manner. An intraoral incision was made 2 mm. below the gingival crest from the second premolar on the left to the second premolar on the right. The mandibular first
Bimaxillary
protrusioqt
and mandibular
retrusion
5
premolars were removed. The mucoperiosteum of the anterior portion of the mandible was reflected to expose the inferior portion of the mandible in a degloving type of procedure. An osteotomy was performed with a Stryker saw in the area of the mandibular first premolar in a vertical direction downward to about. 5 mm. above the inferior border of the mandible. The cut was then directed posteriorly, thus sectioning the mandible in the area of the second premolar. The anterior portion of the mandible was moved forward and downward. The acrylic splint was inserted, and the inferior border of the chin, measuring 3 mm. in height, was then removed and placed over the anterior portion of the chin as an onlay graft. This provided curvature to the anterior portion of the chin. The graft was tied in position with 25-gauge wire. The area was packed temporarily, and attention was turned to the left iliac crest. A separate surgical team obtained a 1 by 1 inch section of bone from the iliac crest. The bone graft was sculptured to fit the defects created by the forward positioning of the anterior mandible. Pedicle-based mucosal flaps were elevated from the right and left cheeks and positioned over the alveolus in the area of the mandibular first premolars. This provided a water-tight closure when it was sutured to the lingual mandibular mucous membrane. The tissues over the degloved mandible were closed with 3-O chromic sutures. The posterior teeth were immobilized by intermaxillary fixation with 25-gauge wire. Ivy loops aided in fixation of the anterior segment (Figs. 8 and 9). The estimated blood loss was 750 C.C. Fluid replacement consisted of 500 C.C. of whole blood, 1,500 C.C. of Ringer’s lactate, and 500 C.C. of 5 per cent dextrose in water. The facial skin was sprayed with benzoin, and pressure dressings were applied to the chin and mandible with Elastoplast. The patient tolerated this procedure well and was transferred to the recovery room in satisfactory condition.
F
6
Oral Surg. July, 1970
Lyons
Fig.
1.8
Postoperative
Fig.
I.‘?
course
The patient was discharged on the fifth postoperative day after an uneventful hospital stay. Approximately 8 weeks postoperatively, the acrylic splint and intramaxillary wires were removed. A Hawley type orthodontic retainer was inserted to retain mandibular stability (Fig. 10). The patient showed much improvement, esthet,ically, functionally, and emotionally (Figs. 11, 12, and 13).
SUMMARY A 16-year-old boy with known emotional and psychologic problems also had a severe maxillary protrusion and a mandibular retrusion. The malocclusion was accentuated a.s a result of wearing a Milwaukee type of back brace with chin rest for 2 years. The orthodontist thought that a satisfactory result could not be achieved by orthodontic treatment. By means of a ma.xillary anterior reduction osteotomy and a mandibular body osteotomy with iliac bone graft, an esthetic and functional result was achieved. The patient’s emotional outlook improved, and his relationship with his friends and with members of the opposite sex was enhanced.
Oral PATH 0 LO GY
VOLUME
30
NUMBER
1
JULY,
1970
Operative oral surgery
Surgical correction of bimaxillary protrusion and mandibular retrusion Bernard $1. Lyons, D.D.S., Galveston, Texas UNIVERSITY
OF TEXAS
MEDICAL
BRANCH
F
unctional and esthetic correction of a severely retruded mandible is one of the most difficult and challenging problems of the orthodontist and oral surgeon. The present article will describe the surgical correction of a severe Angle Class II occlusion. This patient was referred to the Division of Oral and Maxillofacial Surgery at the University of Texas Medical Branch from the Division of Orthopedic Surgery. It was the opinion of the consulting orthodontist that this patient would be best treated surgically. Orthodontic therapy could be delayed until a more favorable position of the mandibular and maxillary arches was attained. CASE REPORT A 16-year-old white boy, in good physical condition, had a history of severe scoliosis of both the dorsal and lumbar spine. He had worn a Milwaukee brace for the past 2 years (Fig. l), and 1 year ago had undergone a fusion of the fourth and fifth lumbar and first sacral vertebrae. The patient’s mother stated that prior to his wearing of the Milwaukee brace he had an “underbite.” However, because of the patient’s habit of resting his chin posterior to, instead of superior to, the chin portion of the Milwaukee brace, this “underbite” appeared to become more severe. Examination
and
preliminary
procedures
Physical examination revealed the patient had a right scoliosis of the dorsal and lumbar spine with a surgical scar in the area of the fourth and fifth lumbar and first sacral vertebrae. There was a maxillary overjet of 18 mm. and an overbite of 12 mm. (Figs. 2, 3, a&
1
2
Lyons
Oral Burg. July, 1970
4). The anterior maxillary teeth rested on the lower lip, and the lip had a tendency to curl downward. The upper lip appeared short, giving the anterior maxillary teeth a protrusive appearance. The lower anterior teeth had overerupted and were in contact with the soft tissue of the palate 7 mm. proximal to the lingual gingiva of the anterior maxillary teeth. The patient had numerous emotional and motivational problems, and there was a history of noncooperation with the orthodontist and orthopedic surgeons. A consultation with the Department of Psychiatry revealed that the patient had a reasonable and realistic attitude toward the propose’d surgical procedure and toward the problems of the postoperative convalescence period. The psychiatrist did not anticipate problems in management, and it was decided to go ahead with the surgical procedure. Panoramic and skull roentgenograms were taken, and a series of maxillary and mandibular study models were constructed. These study models underwent numerous sectionings and reassemblings until a desirable functional and esthetic result was achieved. The combination of maxillary protrusion and mandibular retrusion required surgical correction in both the maxilla and the mandible. It was decided that the correction would be done in two stages. The initial surgical procedure would involve a maxillary osteotomy with removal of the two first bicuspids and a posterior “set-back” of the anterior segment of approximately 10 mm. After a sufficient healing period, the second operative procedure, consisting of a mandibular osteotomy, with an iliac ‘bone graft to fill the defects created, would be performed.
Volume 30 Number 1
Bimaxillary
protrusion
and mandibular
retrusion
3
Prior to the patient’s admission to the hospital, Stout intramaxillary multiple loop wires were placed on the posterior teeth. An acrylic splint was fabricated which would allow positioning of the anterior maxilla 10 mm. proximal to the existing position. These preliminary measures reduced the time normally required for such an operation. Operative
course
The patient was placed on the operating table in a supine position. Following suitable nasotraeheal intubation, he was prepared and draped in the usual manner. A subperiosteal flap was elevated on the buccal surface of each first premolar. A 2 cm. midline incision was made in the palate, and the maxillary first premolars were removed. A tunnel was created from the lingual surfaces of the maxillary first premolars to the area of the vertical palatal incision. Bone was removed from the labial, lingual, and palatal areas in the region of the maxillary first premolars. An incision was then made in the area of the anterior nasal spine. A subperiosteal tunnel was created in the area of the mucobuccal fold along the buccal plate of bone to join the flap over the buceal surfaces of the first premolar-s. A mallet and osteotome were used to section this outer cortex, which completely freed the anterior
P
Fig.
6
F
4
Oral Surg. July, 1970
Lyons
maxillary segment. The segment was set back to the point where the distal surface of the cuspids contacted the mesial sarfaces of the second premolars. The prefabricated acrylic splint was inserted. The anterior segment was properly aligned and held in position adjacent to the posterior segments. Ivy loops were placed on the upper and lower anterior segments to aid in immobilization. The mandibular arch was then positioned into the undersurface of the splint, and the jaws were immobilized with intermaxillary elastic fixation. The soft-tissue flaps were approximated and sutured with 3-O chromic sutures. Blood loss was estimated at 400 C.C. There was no blood replacement, and fluid replacement consisted of 1,000 C.C. of lactated Ringer’s solution. No drains were used. The patient tolerated the procedure well. Postoperative
cows*
Following an uneventful recovery, the patient was discharged from the hospital on the eleventh postoperative day. After 7 weeks of inter-maxillary fixation, the acrylic splint and the intramaxillary wires were removed. The fragments were then retained in proper position with a Hawley type of orthodontic retainer (Fig. 5). This was necessary because the overerupted mandibular anterior teeth now occluded prematurely into the palate, and the resulting trauma would have prevented proper bony union. Two months later the patient was readmitted to the hospital for the second stage of correction of the mandibular retrusion and maxillary protrusion. Prior to readmission, Stout intramaxillary multiple loop wires were again placed and a new acrylic splint was fabricated. The patient required correction of an 8 mm. overjet and a 12 mm. overbite. It was determined that a satisfactory result could be achieved by movement of the anterior mandible into a downward position with forward rotation (Fig. 6). The study models had been sectioned and reassembled in various planes until a desirable functional and esthetic result was obtained. Numerous paper tracings and “cut-outs” had been made to determine the proper position of the mandibular fragments (Fig. 7). The plan was to perform a bilateral osteotomy of the mandibular body in the region of the first premolars. The anterior segment would be rotated to a downward and forward position and the defect obliterated by means of an iliac bone graft. The tracings had revealed that the face would be excessively long after the planned repositioning of the anterior mandibular segment. It was therefore decided that a reduction in the length of the chin (Fig. 7), followed by placement of the excised bone on the anterior surface of the mandible, would both decrease the excessive length of the face and provide a more esthetic result. Operative
course
Following adequate nasotracheal intubation, the face and left hip were prepared in the customary manner. An intraoral incision was made 2 mm. below the gingival crest from the second premolar on the left to the second premolar on the right. The mandibular first
Bimaxillary
protrusioqt
and mandibular
retrusion
5
premolars were removed. The mucoperiosteum of the anterior portion of the mandible was reflected to expose the inferior portion of the mandible in a degloving type of procedure. An osteotomy was performed with a Stryker saw in the area of the mandibular first premolar in a vertical direction downward to about. 5 mm. above the inferior border of the mandible. The cut was then directed posteriorly, thus sectioning the mandible in the area of the second premolar. The anterior portion of the mandible was moved forward and downward. The acrylic splint was inserted, and the inferior border of the chin, measuring 3 mm. in height, was then removed and placed over the anterior portion of the chin as an onlay graft. This provided curvature to the anterior portion of the chin. The graft was tied in position with 25-gauge wire. The area was packed temporarily, and attention was turned to the left iliac crest. A separate surgical team obtained a 1 by 1 inch section of bone from the iliac crest. The bone graft was sculptured to fit the defects created by the forward positioning of the anterior mandible. Pedicle-based mucosal flaps were elevated from the right and left cheeks and positioned over the alveolus in the area of the mandibular first premolars. This provided a water-tight closure when it was sutured to the lingual mandibular mucous membrane. The tissues over the degloved mandible were closed with 3-O chromic sutures. The posterior teeth were immobilized by intermaxillary fixation with 25-gauge wire. Ivy loops aided in fixation of the anterior segment (Figs. 8 and 9). The estimated blood loss was 750 C.C. Fluid replacement consisted of 500 C.C. of whole blood, 1,500 C.C. of Ringer’s lactate, and 500 C.C. of 5 per cent dextrose in water. The facial skin was sprayed with benzoin, and pressure dressings were applied to the chin and mandible with Elastoplast. The patient tolerated this procedure well and was transferred to the recovery room in satisfactory condition.
F
6
Oral Surg. July, 1970
Lyons
Fig.
1.8
Postoperative
Fig.
I.‘?
course
The patient was discharged on the fifth postoperative day after an uneventful hospital stay. Approximately 8 weeks postoperatively, the acrylic splint and intramaxillary wires were removed. A Hawley type orthodontic retainer was inserted to retain mandibular stability (Fig. 10). The patient showed much improvement, esthet,ically, functionally, and emotionally (Figs. 11, 12, and 13).
SUMMARY A 16-year-old boy with known emotional and psychologic problems also had a severe maxillary protrusion and a mandibular retrusion. The malocclusion was accentuated a.s a result of wearing a Milwaukee type of back brace with chin rest for 2 years. The orthodontist thought that a satisfactory result could not be achieved by orthodontic treatment. By means of a ma.xillary anterior reduction osteotomy and a mandibular body osteotomy with iliac bone graft, an esthetic and functional result was achieved. The patient’s emotional outlook improved, and his relationship with his friends and with members of the opposite sex was enhanced.