- Email: [email protected]
Correction of maxillary excess by anterior maxillary osteotomy
oral surgery oral medicine oral pathology WM, seclionson endodontics Volume
dental
and
43, Number
3, March.
radiology
1977
oral surgery Editor: ROBERT
B. SHIRA,
D.D.S.
School of Dental Medicine, Tufts 1 Kneeland St. Boston, Massachusetts 02111
University
Correction of maxillary excess by anterior maxillary osteotomy A review
William
of three
basic
H. Bell, D.D.S.,*
DEPARTMENT ABNORMALITIES,
OF
SURGERY, THE
procedures
Dallas, Texas CENTER
UNIVERSITY
FOR OF
CORRECTION
TEXAS
HEALTH
OF
DENTO-FACIAL
SCIENCE
CENTER
With proper planning, execution, and follow-up care, the anterior maxilla can be surgically repositioned in selected cases to correct the anteroposterior, vertical, and horizontal manifestations of maxillary excess. The technical problems in planning and design for the necessary bony and soft-tissue incisions for three basic anterior maxillary osteotomy techniques are discussed and illustrated. Selection of the most appropriate procedure is based upon the type of positional change that is planned.
M
axillary deformities have been recognized and described for centuries, but the challenge to correct them surgically in the anterior maxilla was not met until the turn of the century. Bold attempts to move the anterior maxilla were *Associate
Professor,
Division
of Oral
Surgery.
323
324
Oral surg.
Bell
ivlrcll
(
> 1977
first made 1)~ Cohn-Stock, \\‘assniund,’ anti Spader” without any hlow~~~$r of the I)iologic~ basis for the healing of suc.11 snrgic~ally c+rcatc~tl wonutls. ,2nal,vsis of (‘ohl~-Stock’s initial attempt at surgic*al rc~tl.ol)ositiolliilg of the anterior tnasilla intlicatrs that 11c fcarctl the CYJIISC~~II~~IICT~S of sncll 21surgical ~PO~YY~~W.I IC attcmptctl to ob\-iatc them l,- l)rotluc+ig a grccnstiek fractures ot’ tile ;Illtcrior* maxilla through a transvc>rsc palatal incision. The eonscqncnt relapse after the fixation apl)lianccs wcrc rcmo\-(~1 is ;IJll])lC tcdimoiiy to the fact that iltl('(lll?ltC' mobility \\-a~ not attainc~tl 1)~.the, ()I)(~l~i~tioll.Snlwqnent motlifications in the tIesign of the l~oiiy and soft-tissue iticisions II!- \\~;~ii~iui~l.~ (“u~);ir,’ ant1 IVundcwP liaw since provided more tlircc+t il(‘c(‘ssto th(l nl;lriII;l while still maintaining the 1)100tl suppl- to the teeth antI lwli~~. With proper planning aiitl csccntion, the anterior maxilla c’iln bc surgically espandctl, narrowed, ~l(~\.ilJl~('~~. or r~~tractcd by any one of three I)asic anterio maxillary ostcotoniy tccliiliqncs.“~ ‘. I 1)ircct ac+cess to specific anatomic arcas of the maxilla is facilitatctl IQ- \-aryiiig tli(l tlcsign of the soft-tissue incisions. Selc(dtion of the most appropi%tc surgical ~~r~~c~cvlnw is l~ascdupon the type of positional change that is plat~ned. This article dcscribcls three l)asic surgical tccllniqucs for rcyositioning the anterior portion of the musill;~ ;rl~l the inclicati(ms for the use of each methotl to correct the aiitcropostcrior, vertical, and horizontal manifestations of maxillary ESCCSS. WUNDERER
METHOD
When posterior movcmcnt 01’ the anterior maxilla is the dominant clinical objcctirc, a trails\-crs(J pnlatal niucosal incision provides direct n~ccss to the planned palatal ostcctomy site and cscellcnt visualization of the bony area which is most likely to be incompletely ostectomizcd. Kith this mcthocl, vertical segments of bone can be most readily removed in the molar regions. I)ual a(xcessto both th(x buccal and palatal aspects of the alrcolar ridges is also afforded x~lzen vertical interdental osteotomics iire 1)lannctl between closely spaced teeth (Fig. 1). Surgical
technique
The surgical procctlure is usually pcrformcd in a single stage with the patirn? under general nasoentlotracheal anesthesia. Local anesthesia or saline solution with a vasoconstrictor is infiltrated into the mucolabial and mudmccal sulci for hemostasis.Acr$atecl arch bars, orthodontic appliances, or east-metal splints ma)be used for fixation of the mobilized anterior maxilla. Intcrniasillar~ fixation is usually not necessary unless mandibular ostcotomics are pcrformetl simultallcously.
Retractors arc’ positionctl to attain csposurc of the alltrrior aspect of the maxillary vestibule (Fig. 1, 11). ,I vertical incision is ma& through the mucoperiostcum in the depth of the vestibulr and carried clown to the interdental space immediately anterior to the plannctl ostrotomy site. The incision is tlesigned so t’hat the line of ground closure is positionccl over bone. The posterior margin of the incision is raised with an elevator ant1 retracted to csposc the planned ostectomy site. The an&o-inferior margin of the incision is left intact. By subpcriosteal tunneling beneath the anterosupcrior margin of the incision, the piriform
Volume Number
43 3
Anterior
m.axillarg
osteotomy
325
Pig. 2. Incisions of soft tissue and bone for correction of anterior-posterior maxillary excess by Wunderer technique of anterior maxillary osteotomy. A, Preoperative deformity: prominent upper lip, acute nasolabial angle, mild degree of lip incompetence, extensive overjet, and Class II malocclusion; bold lines illustrate planned ostectomy site to facilitate posterior movement of the anterior maxilla (arrow). B, Buccal ostectomy of lateral maxilla through retracted wound margins. C, Transpalatal osteetomy through retracted mucosal wound margins. D and E, The anterior maxilla is fractured free of most of its bony attachments by superior movement of the segment. F, Indicated bone sculpturing is done with the anterior maxilla raised and the segments separated; the anterior maxillary segment is sectioned from the palatal side to facilitate interin&al osteotomy. G, Splitting of segment by malletting a fine sharp osteotome between the sectioned fragments. H, Excision of nasal crest of the anterior maxilla is done with the segment raised. I, Repositioned maxilla fixed to posterior teeth with an arch wire which is ligated to the posterior teeth.
326
Bell
Oral March,
Surg. 1977
Fig. 2. Incisions of soft tissue and bone for correction of anterior-vertical maxillary excess bv “downfracturing” technique of anterior maxillary osteotomy. 8, Preoperative deformity : prominent upper lip, acute nasolabial angle, short columella, lip incompetence, and Class II bold lines illustrate planned malocclusion associated with excessive overjet and overbite; ostectomy site to facilitate superior and posterior movement of the anterior maxilla {nrrou?s). B, Buccal ostectomy of lateral maxilla through retracted wound margins. C, Alternate method of buccal ostectomy below inferiorly retracted mucoperiosteal flap (technique after method of Bruce N. Epkere). D, Transpalatal ostectomy made through buccal ostectomy site. E, Osteotome malletted through the midpalatal bone to complete the palatal osteotomy. F, Maxilla in “downfractured” position to facilitate reduction in height of nasal crest of maxilla and superior aspect of the anterior maxilla. G, Repositioned maxilla fixed to posterior teeth with an arch wire which is ligated to the posterior teeth.
Volume Number
43 3
Anterior
maxillary
osteotomy
327
aperture is visualized. The proposed bone incisions are etched in the lateral apsect of the maxilla with a fine fissure burr. The axial inclination and length of the teeth are assessed by direct visualization and palpation of the bone encasing the teeth to be extracted and the adjacent teeth. The findings, when correlated with periapical radiographic studies, help determine the length of the vertical bone cuts. After the teeth in the planned ostectomy sites are extracted, vertical osteotomies are made in the alveolar bone with a fissure burr on an oscillating saw. The forefinger is positioned on the palatal mucosa to feel the burr or saw as it transects the maxilla, thereby minimizing trauma to the soft tissues. After a measured vertical section of bone is removed, the osteotomy is carried about 4 mm. above the adjacent premolar and canine apices and angled medially into the inferolateral portion of the piriform aperture. A periosteal elevator can be positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the mucosa when the subapical bone cuts are made. A similar procedure is performed on the opposite side. A Dingman mouth prop may be used to visualize the palate. An arcing incision through the palatal mucosa is carried from the interdental space anterior to the planned vertical ostectomy site of one side to the contralateral interdental space ; the convex aspect of the curve is posterior to the incisive canal (Fig. 1, C). The posterior palatal mucosal wound margin is raised with an elevator and retracted posteriorly several millimeters beyond the planned ostectomy site. After the proposed bone incision is etched into the palatal bone, the buccal ostectomy sites are connected by a transpalatal ostectomy, made under direct vision. A fissure type of burr with a smooth, rounded tip is used to prevent laceration of the underlying nasal mucosa. In the midline the osteotomy is carried somewhat deeper to section the thicker nasal crest of the maxilla. The anterior maxillary segment is partially mobilized with posterior and inferior digital pressure (Fig. 1, D and E). After the anterior maxilla is fractured free of most of its remaining bony attachments by superior movement of the segment, a large osteotome is manipulated between the sectioned proximal and distal segments to attain greater mobility and separation. With the anterior maxilla raised and the segments separated, the remaining bony connections between the segments are removed (Fig. 1, F). Direct access to the palatal and nasal sides of the anterior fragment facilitates close apposition of the sectioned palatal and buccal segments. Indicated bone sculpturing is done under direct vision through the palatal and buccal ostectomy sites. The interdental bone cuts must be made very carefully to attain close approximation of the segments and to ensure that the adjacent teeth in the ostectomy site remain encased in bone. An occlusal wafer splint is utilized to guide the anterior maxilla into the desired position. When interincisal osteotomy or ostectomy is indicated to increase or decrease the intercanine width and improve the canine-premolar relationship, the anterior maxillary segment is easily sectioned from the palatal side (Fig. 1, F and G). A midpalatal sagittal incision is made through the palatal mucosa extending from the center of the transverse palatal mucosa incision anteriorly to the incisive canal. After the superior portion of the anterior maxillary segment is sectioned midsagittally with a fissure burr, the segment is split by malletting a fine, sharp osteotome between the sectioned fragments into
328
Bell
Oral March,
Surg. 1977
the interradicular area. An osteotome positioned between the sectioned fragments and into the interradicular area is gradually twisted to attain complete mobility and separation of the segments. With the two segments distracted, the indicated interdental bone excision can be accomplished safely with fine fissure burrs. With the segment raised, the nasal mucoperiosteum can be carefully detached from the superior aspect of the anterior maxilla to facilitate excision of the nasal crest of the anterior maxilla and reduction of the bony or cartilaginous nasal septum (Fig. 1, H) . When significant intrusion of the anterior maxilla is indicated and reduction of the anterior nasal spine is contraindicated, the mucoperichondrium attached to either side of the nasal septum can be raised to facilitate excision of a segment of cartilage, the dimensions of which are comparable to the amount of planned maxillary movement. The anterior maxillary segment is keyed into an acrylic splint and fixed to the posterior teeth with an arch wire which is ligated to the posterior teeth (Fig. 1, I). Redundant palatal mucosa may be excised to facilitate closure of the palatal wound margins, if excessive. When the posterior margin of the palatal flap has been raised minimally, it is unnecessary to use a surgical stent or dressing. CUPAR
METHOD
When superior repositioning of the maxilla is the dominant clinical objective, the “downfracturing” technique, modified after Cupar,4 provides direct access to the superior maxilla and excellent visualization of the bony area, which is most difficult to remove (Fig. 2). When vertical maxillary excessis present, there is usually between 10 and 15 mm. of bone between the nasal floor and the incisor apices. Such anatomy allows the maxilla to be moved superiorly at the expense of the bone between the nasal floor and the anterior tooth apices and the maxillary nasal spine. Surgical
technique
Retractors are positioned to attain exposure of the maxillary vestibule (Fig. 2, B) . A horizontal incision is made through the labial and buccal mucoperiosteum above the mucogingival junction, extending at least one tooth distal to the planned ostectomy site of one side to a similar area on the opposite side of the maxilla. The superior margin of the incision is raised to expose the lateral wall of the maxilla and piriform aperture. In the area where the premolar tooth is to be extracted and the ostectomy perfoimed, the mucoperiosteal flap can be retracted inferiorly (Fig. 2, C) or a vertical incision can be made through the inferior margin of the incision in the interdental space immediately anterior to the planned osteotomy site (Fig. 2, B) . When a vertical incision is made, the posterior margin of the vertical incision is raised and retracted to facilitate visualization of the planned ostectomy site. After the mucoperiosteum is elevated from the anterior and lateral walls of the nasal cavity, a measured section of the lateral maxilla is excised from the extraction sites. The vertical bone incisions are carried 4 or 5 mm. above the canine apices and angled medially into the piriform aperture. Next, a transpalatal osteotomy is made through the vertical ostectomy sites (Fig. 2, E and D). No attempt is made, however, to remove the planned
Volume Number
Anterior
43 3
maxillary
osteotomy
329
amount of bone from the palate at this time. An osteotome is malletted into the midpalatal and lateral osteotomy sites to facilitate downfracturing the anterior maxilla. The superior and posterior surfaces of the anterior maxilla can then be directly visualized (Fig. 2, P). The nasal crest of the maxilla and the superior aspect of the anterior maxilla are reduced in height to facilitate the superior movement of the anterior maxilla without buckling the nasal septum. Bone is readily excised from the transpalatal and vertical ostectomy sites to attain the planned movement. A groove is made in the midline of the superior maxilla to accommodate the cartilaginous septum. When superior movement of the maxilla exceeds the available bone, a portion of the cartilaginous nasal septum is removed. The anterior maxillary segment, pedicled to the palatal soft tissue, is manipulated and any bony areas which resist easy digital placement of the segment into the preoperatively planned position are removed (Fig. 2, G) . After the segment is moved into the desired position, the anterior maxilla is ligated to the POSterior teeth with an arch wire ligated to the posterior teeth. After thorough lavage of the wound, the labial and buccal soft-tissue incisions are closed with catgut sutures. WASSMUND
METHOD
Via combined labial and palatal incisions, an excellent dual vascular supply to the anterior maxillary segment is maintained by preservation of both palatal and labiobuccal soft-tissue pedicles. A modification of the technique facilitates multiple osteotomies through vertical labiobuccal mucosal incisions for closure of multiple interdental diastemas.2 Technically, however, it is more difficult to gain accessto the superior and palatal aspects of the anterior maxilla. As a result, the actual osteotomies in these areas, which are performed in a relatively blind fashion, may be more problematic than the Wunderer or Cupar techniques when significant superior or posterior movement is planned. Surgical
technique
A vertical incision is made through the gingiva in the interdental space immediately anterior to the distal bony margin of the planned ostectomy (Fig. 3, A). As the incision is carried superiorly into the depth of the vestibule, it is directed slightly anteriorly, so that the line of wound closure is positioned over bone. The posterior margin of the incision is raised with an elevator to expose the lateral maxilla ; the antero-inferior margin remains attached to the underlying bone. By subperiosteal tunneling beneath the anterosuperior margin of the incision, the lateral-inferior portion of the bony anterior nasal aperture is visualized. A vertical incision is made through the mucoperiosteum overlying the anterior nasal spine and carried inferiorly 3 or 4 mm. above the free gingival margin. The wound margins are raised and retracted to expose the anterior nasal spine and the superior aspect of the previously raised mucoperiosteal flaps. A periosteal elevator is positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the nasal mucosa when the subapical bone cuts are made. After the first premolar teeth in the planned ostectomy sites are extracted,
330
Bell
Oral March,
Surg. 1977
Big. 3. A, Buccal ostectomy of lateral maxilla through retracted wound margins; periosteal elevator positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the nasal mucosa when the subapical bone cut is made. B, Transpalatal ostectomy made through buccal ostectomy site. C, Excision of midpalatal bone facilitated by midpalatal sagittal mucosal incision. D, Separation of nasal septum from superior part of maxilla with osteotome. E and F, Interincisal osteotomy accomplished with fissure burr and osteotome through midline retracted wound margins.
Volume Number
43 3
Anterior
ma.xillary
osteotomy
331
the proposed bone cuts are etched in the lateral aspect of the maxilla with a fine fissure burr. A measured vertical section of alveolar bone is excised with a fissure burr or oscillating saw down to the junction of the horizontal and vertical parts of the maxilla. The forefinger is positioned on the palatal mucosa to determine when the palatal bone is sectioned by the burr or saw blade (Fig. 3, B) . Next, the buccal bone incision is carried 3 or 4 mm. above the adjacent canine apex and then angled medially to the inferolateral part of the piriform rim (Fig. 3, A). Finally, the wound is packed with Surgicel or gauze for hemostasisand a similar procedure is carried out on the opposite side. The lateral palatal and transpalatal ostectomies are completed through the vertical ostectomy sites. After a subperiosteal tunnel is developed in the area of the planned palatal ostectomy, the palatal bone is sectioned transversely from the vertical ostectomy site of one side to the contralateral vertical ostectomy site. Digital pressure on the palatal mucosa is essential to make this relatively blind cut without traumatizing the palatal and nasal mucosa. The transverse palatal bone incision can be facilitated by a midpalatal sagittal mucosal incision immediately distal to the incisive foramen (Fig. 3, C) , The thicker midpalatal bone is then excised through the retracted wound margins. Through the wound margins of the vertical midline incision over the anterior nasal spine, the mucoperiosteum is elevated from the anterior nasal floor and nasal septum to facilitate separation of the anterior maxillary segment from the cartilaginous septum (Fig. 3, E) . A notched septal osteotome, which is positioned above the anterior nasal spine and parallel with the hard palate, is malletted between the anterior parts of the nasal septum and maxilla. The anterior maxilla is then mobilized with posterior and inferior digital pressure. A prefabricated acrylic wafer splint, made from the sectioned articulated study casts, is used as an index for determining when the segment is positioned properly. The bony areas on either the proximal or distal segments,which prevent the anterior maxillary segment from being positioned properly, are excised with fine fissure burrs. When interincisal osteotomy or ostectomy is indicated to increase or decrease the intercanine width, improve the canine-premolar relationship, or close an interincisal diastema, the anterior maxillary segment is sectioned through the labial or palatal mucosal incisions (Fig. 3, E and F) . After the superior part of the anterior maxilla is sectioned midsagittally with a fissure burr, the segment is split by malletting a fine sharp osteotome between the sectioned fragments into the interradicular area. Complete mobility and separation of the segments is attained by manipulating an osteotome positioned in the interradicular area of the sectioned fragments. With the two segments distracted, the indicated interdental bone sculpturing is accomplished. SUMMARY
The excellent accessibility and visibility afforded by the Le Fort I “downfracturing” technique for simultaneous anterior and posterior maxillary osteotomies has in recent years obviated the need for many isolated anterior maxillary osteotomies. This procedure with its many modifications7 gives the surgeon consider-
332
Bell
Oral March,
Surg. 1977
ably more latitude in correcting the anteroposterior, vertical, and horizontal manifestations of maxillary excess than has been possible with previously used anterior maxillary osteotomy techniques. Nevertheless, with proper planning, execution, and follow-up care, the anterior maxilla can be moved into a stable relationship with the mandible.8 Complete mobility, preservation of viability by proper design of the bony and soft-tissue incisions,g and adequate fixation during the healing phase are essential to obtain this objective. The technical problems in planning and design for the necessary bony and soft-tissue incisions for three basic anterior maxillary osteotomy techniques are discussed and illustrated. REFERENCES 1. Cohn-Stock,
2. 2 5. 6. 7. 8. 9.
G. : Die Chirurgische Immediatregulierung der Kiefer, Speziell die Chirurgische Behandlung der Prognathie, Vjschr. Zahnheilk., Berlin 37: 320, 1921. Wassmund, M. : Frakturen und Luxationen des Gesichtsschadels, Berlin, 1927. Spanier, F.: Prognathie-Operationen, Z. Zahnarztl. Orthop., Munchen 24: 76, 1932. Cupar, I.: Die chirurgisehe Behandlung der Formund Stellungsveranderungen des Oberkiefers, Ost. Z. Stomatol. 51: 565, 1954; Buss. SC. Cons. Acad. R. P. F. Yougosl. 2: 60, 1955. Wunderer, S. : Erfahrungen mit der Operativen Behandlung Hochgradiger Prognathien, Dtsch. Zahn-Mund-Kieferheilkd. 39: 451, 1963. Eoker. B. N.: Personal communication. Bill, %. H.: Le Fort I Osteotomy for Correction of Maxillary Deformities, J. Oral Surg. 33(6) : 412-426, 1975. Bell. W. H.. and Dann. J. J.: Correction of Dento-Facial Deformities bv Surgerv v ” in the Anterior Part of the Jaws, Am. J. Orthod. 64(2): 162-187, 1973. Bell, W. H.: Biologic Basis for Maxillary Osteotomies, Am. J. Phys. Anthropol. 38(2): 279-289, 1973.
Reprint
requests
to:
Dr. William H. Bell Division of Oral Surgery Department of Surgery Center for Correction of Dento-facial University of Texas Health Science 5323 Harry Hines Blvd. Dallas, Texas 75235
Abnormalities Center
dental
and
43, Number
3, March.
radiology
1977
oral surgery Editor: ROBERT
B. SHIRA,
D.D.S.
School of Dental Medicine, Tufts 1 Kneeland St. Boston, Massachusetts 02111
University
Correction of maxillary excess by anterior maxillary osteotomy A review
William
of three
basic
H. Bell, D.D.S.,*
DEPARTMENT ABNORMALITIES,
OF
SURGERY, THE
procedures
Dallas, Texas CENTER
UNIVERSITY
FOR OF
CORRECTION
TEXAS
HEALTH
OF
DENTO-FACIAL
SCIENCE
CENTER
With proper planning, execution, and follow-up care, the anterior maxilla can be surgically repositioned in selected cases to correct the anteroposterior, vertical, and horizontal manifestations of maxillary excess. The technical problems in planning and design for the necessary bony and soft-tissue incisions for three basic anterior maxillary osteotomy techniques are discussed and illustrated. Selection of the most appropriate procedure is based upon the type of positional change that is planned.
M
axillary deformities have been recognized and described for centuries, but the challenge to correct them surgically in the anterior maxilla was not met until the turn of the century. Bold attempts to move the anterior maxilla were *Associate
Professor,
Division
of Oral
Surgery.
323
324
Oral surg.
Bell
ivlrcll
(
> 1977
first made 1)~ Cohn-Stock, \\‘assniund,’ anti Spader” without any hlow~~~$r of the I)iologic~ basis for the healing of suc.11 snrgic~ally c+rcatc~tl wonutls. ,2nal,vsis of (‘ohl~-Stock’s initial attempt at surgic*al rc~tl.ol)ositiolliilg of the anterior tnasilla intlicatrs that 11c fcarctl the CYJIISC~~II~~IICT~S of sncll 21surgical ~PO~YY~~W.I IC attcmptctl to ob\-iatc them l,- l)rotluc+ig a grccnstiek fractures ot’ tile ;Illtcrior* maxilla through a transvc>rsc palatal incision. The eonscqncnt relapse after the fixation apl)lianccs wcrc rcmo\-(~1 is ;IJll])lC tcdimoiiy to the fact that iltl('(lll?ltC' mobility \\-a~ not attainc~tl 1)~.the, ()I)(~l~i~tioll.Snlwqnent motlifications in the tIesign of the l~oiiy and soft-tissue iticisions II!- \\~;~ii~iui~l.~ (“u~);ir,’ ant1 IVundcwP liaw since provided more tlircc+t il(‘c(‘ssto th(l nl;lriII;l while still maintaining the 1)100tl suppl- to the teeth antI lwli~~. With proper planning aiitl csccntion, the anterior maxilla c’iln bc surgically espandctl, narrowed, ~l(~\.ilJl~('~~. or r~~tractcd by any one of three I)asic anterio maxillary ostcotoniy tccliiliqncs.“~ ‘. I 1)ircct ac+cess to specific anatomic arcas of the maxilla is facilitatctl IQ- \-aryiiig tli(l tlcsign of the soft-tissue incisions. Selc(dtion of the most appropi%tc surgical ~~r~~c~cvlnw is l~ascdupon the type of positional change that is plat~ned. This article dcscribcls three l)asic surgical tccllniqucs for rcyositioning the anterior portion of the musill;~ ;rl~l the inclicati(ms for the use of each methotl to correct the aiitcropostcrior, vertical, and horizontal manifestations of maxillary ESCCSS. WUNDERER
METHOD
When posterior movcmcnt 01’ the anterior maxilla is the dominant clinical objcctirc, a trails\-crs(J pnlatal niucosal incision provides direct n~ccss to the planned palatal ostcctomy site and cscellcnt visualization of the bony area which is most likely to be incompletely ostectomizcd. Kith this mcthocl, vertical segments of bone can be most readily removed in the molar regions. I)ual a(xcessto both th(x buccal and palatal aspects of the alrcolar ridges is also afforded x~lzen vertical interdental osteotomics iire 1)lannctl between closely spaced teeth (Fig. 1). Surgical
technique
The surgical procctlure is usually pcrformcd in a single stage with the patirn? under general nasoentlotracheal anesthesia. Local anesthesia or saline solution with a vasoconstrictor is infiltrated into the mucolabial and mudmccal sulci for hemostasis.Acr$atecl arch bars, orthodontic appliances, or east-metal splints ma)be used for fixation of the mobilized anterior maxilla. Intcrniasillar~ fixation is usually not necessary unless mandibular ostcotomics are pcrformetl simultallcously.
Retractors arc’ positionctl to attain csposurc of the alltrrior aspect of the maxillary vestibule (Fig. 1, 11). ,I vertical incision is ma& through the mucoperiostcum in the depth of the vestibulr and carried clown to the interdental space immediately anterior to the plannctl ostrotomy site. The incision is tlesigned so t’hat the line of ground closure is positionccl over bone. The posterior margin of the incision is raised with an elevator ant1 retracted to csposc the planned ostectomy site. The an&o-inferior margin of the incision is left intact. By subpcriosteal tunneling beneath the anterosupcrior margin of the incision, the piriform
Volume Number
43 3
Anterior
m.axillarg
osteotomy
325
Pig. 2. Incisions of soft tissue and bone for correction of anterior-posterior maxillary excess by Wunderer technique of anterior maxillary osteotomy. A, Preoperative deformity: prominent upper lip, acute nasolabial angle, mild degree of lip incompetence, extensive overjet, and Class II malocclusion; bold lines illustrate planned ostectomy site to facilitate posterior movement of the anterior maxilla (arrow). B, Buccal ostectomy of lateral maxilla through retracted wound margins. C, Transpalatal osteetomy through retracted mucosal wound margins. D and E, The anterior maxilla is fractured free of most of its bony attachments by superior movement of the segment. F, Indicated bone sculpturing is done with the anterior maxilla raised and the segments separated; the anterior maxillary segment is sectioned from the palatal side to facilitate interin&al osteotomy. G, Splitting of segment by malletting a fine sharp osteotome between the sectioned fragments. H, Excision of nasal crest of the anterior maxilla is done with the segment raised. I, Repositioned maxilla fixed to posterior teeth with an arch wire which is ligated to the posterior teeth.
326
Bell
Oral March,
Surg. 1977
Fig. 2. Incisions of soft tissue and bone for correction of anterior-vertical maxillary excess bv “downfracturing” technique of anterior maxillary osteotomy. 8, Preoperative deformity : prominent upper lip, acute nasolabial angle, short columella, lip incompetence, and Class II bold lines illustrate planned malocclusion associated with excessive overjet and overbite; ostectomy site to facilitate superior and posterior movement of the anterior maxilla {nrrou?s). B, Buccal ostectomy of lateral maxilla through retracted wound margins. C, Alternate method of buccal ostectomy below inferiorly retracted mucoperiosteal flap (technique after method of Bruce N. Epkere). D, Transpalatal ostectomy made through buccal ostectomy site. E, Osteotome malletted through the midpalatal bone to complete the palatal osteotomy. F, Maxilla in “downfractured” position to facilitate reduction in height of nasal crest of maxilla and superior aspect of the anterior maxilla. G, Repositioned maxilla fixed to posterior teeth with an arch wire which is ligated to the posterior teeth.
Volume Number
43 3
Anterior
maxillary
osteotomy
327
aperture is visualized. The proposed bone incisions are etched in the lateral apsect of the maxilla with a fine fissure burr. The axial inclination and length of the teeth are assessed by direct visualization and palpation of the bone encasing the teeth to be extracted and the adjacent teeth. The findings, when correlated with periapical radiographic studies, help determine the length of the vertical bone cuts. After the teeth in the planned ostectomy sites are extracted, vertical osteotomies are made in the alveolar bone with a fissure burr on an oscillating saw. The forefinger is positioned on the palatal mucosa to feel the burr or saw as it transects the maxilla, thereby minimizing trauma to the soft tissues. After a measured vertical section of bone is removed, the osteotomy is carried about 4 mm. above the adjacent premolar and canine apices and angled medially into the inferolateral portion of the piriform aperture. A periosteal elevator can be positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the mucosa when the subapical bone cuts are made. A similar procedure is performed on the opposite side. A Dingman mouth prop may be used to visualize the palate. An arcing incision through the palatal mucosa is carried from the interdental space anterior to the planned vertical ostectomy site of one side to the contralateral interdental space ; the convex aspect of the curve is posterior to the incisive canal (Fig. 1, C). The posterior palatal mucosal wound margin is raised with an elevator and retracted posteriorly several millimeters beyond the planned ostectomy site. After the proposed bone incision is etched into the palatal bone, the buccal ostectomy sites are connected by a transpalatal ostectomy, made under direct vision. A fissure type of burr with a smooth, rounded tip is used to prevent laceration of the underlying nasal mucosa. In the midline the osteotomy is carried somewhat deeper to section the thicker nasal crest of the maxilla. The anterior maxillary segment is partially mobilized with posterior and inferior digital pressure (Fig. 1, D and E). After the anterior maxilla is fractured free of most of its remaining bony attachments by superior movement of the segment, a large osteotome is manipulated between the sectioned proximal and distal segments to attain greater mobility and separation. With the anterior maxilla raised and the segments separated, the remaining bony connections between the segments are removed (Fig. 1, F). Direct access to the palatal and nasal sides of the anterior fragment facilitates close apposition of the sectioned palatal and buccal segments. Indicated bone sculpturing is done under direct vision through the palatal and buccal ostectomy sites. The interdental bone cuts must be made very carefully to attain close approximation of the segments and to ensure that the adjacent teeth in the ostectomy site remain encased in bone. An occlusal wafer splint is utilized to guide the anterior maxilla into the desired position. When interincisal osteotomy or ostectomy is indicated to increase or decrease the intercanine width and improve the canine-premolar relationship, the anterior maxillary segment is easily sectioned from the palatal side (Fig. 1, F and G). A midpalatal sagittal incision is made through the palatal mucosa extending from the center of the transverse palatal mucosa incision anteriorly to the incisive canal. After the superior portion of the anterior maxillary segment is sectioned midsagittally with a fissure burr, the segment is split by malletting a fine, sharp osteotome between the sectioned fragments into
328
Bell
Oral March,
Surg. 1977
the interradicular area. An osteotome positioned between the sectioned fragments and into the interradicular area is gradually twisted to attain complete mobility and separation of the segments. With the two segments distracted, the indicated interdental bone excision can be accomplished safely with fine fissure burrs. With the segment raised, the nasal mucoperiosteum can be carefully detached from the superior aspect of the anterior maxilla to facilitate excision of the nasal crest of the anterior maxilla and reduction of the bony or cartilaginous nasal septum (Fig. 1, H) . When significant intrusion of the anterior maxilla is indicated and reduction of the anterior nasal spine is contraindicated, the mucoperichondrium attached to either side of the nasal septum can be raised to facilitate excision of a segment of cartilage, the dimensions of which are comparable to the amount of planned maxillary movement. The anterior maxillary segment is keyed into an acrylic splint and fixed to the posterior teeth with an arch wire which is ligated to the posterior teeth (Fig. 1, I). Redundant palatal mucosa may be excised to facilitate closure of the palatal wound margins, if excessive. When the posterior margin of the palatal flap has been raised minimally, it is unnecessary to use a surgical stent or dressing. CUPAR
METHOD
When superior repositioning of the maxilla is the dominant clinical objective, the “downfracturing” technique, modified after Cupar,4 provides direct access to the superior maxilla and excellent visualization of the bony area, which is most difficult to remove (Fig. 2). When vertical maxillary excessis present, there is usually between 10 and 15 mm. of bone between the nasal floor and the incisor apices. Such anatomy allows the maxilla to be moved superiorly at the expense of the bone between the nasal floor and the anterior tooth apices and the maxillary nasal spine. Surgical
technique
Retractors are positioned to attain exposure of the maxillary vestibule (Fig. 2, B) . A horizontal incision is made through the labial and buccal mucoperiosteum above the mucogingival junction, extending at least one tooth distal to the planned ostectomy site of one side to a similar area on the opposite side of the maxilla. The superior margin of the incision is raised to expose the lateral wall of the maxilla and piriform aperture. In the area where the premolar tooth is to be extracted and the ostectomy perfoimed, the mucoperiosteal flap can be retracted inferiorly (Fig. 2, C) or a vertical incision can be made through the inferior margin of the incision in the interdental space immediately anterior to the planned osteotomy site (Fig. 2, B) . When a vertical incision is made, the posterior margin of the vertical incision is raised and retracted to facilitate visualization of the planned ostectomy site. After the mucoperiosteum is elevated from the anterior and lateral walls of the nasal cavity, a measured section of the lateral maxilla is excised from the extraction sites. The vertical bone incisions are carried 4 or 5 mm. above the canine apices and angled medially into the piriform aperture. Next, a transpalatal osteotomy is made through the vertical ostectomy sites (Fig. 2, E and D). No attempt is made, however, to remove the planned
Volume Number
Anterior
43 3
maxillary
osteotomy
329
amount of bone from the palate at this time. An osteotome is malletted into the midpalatal and lateral osteotomy sites to facilitate downfracturing the anterior maxilla. The superior and posterior surfaces of the anterior maxilla can then be directly visualized (Fig. 2, P). The nasal crest of the maxilla and the superior aspect of the anterior maxilla are reduced in height to facilitate the superior movement of the anterior maxilla without buckling the nasal septum. Bone is readily excised from the transpalatal and vertical ostectomy sites to attain the planned movement. A groove is made in the midline of the superior maxilla to accommodate the cartilaginous septum. When superior movement of the maxilla exceeds the available bone, a portion of the cartilaginous nasal septum is removed. The anterior maxillary segment, pedicled to the palatal soft tissue, is manipulated and any bony areas which resist easy digital placement of the segment into the preoperatively planned position are removed (Fig. 2, G) . After the segment is moved into the desired position, the anterior maxilla is ligated to the POSterior teeth with an arch wire ligated to the posterior teeth. After thorough lavage of the wound, the labial and buccal soft-tissue incisions are closed with catgut sutures. WASSMUND
METHOD
Via combined labial and palatal incisions, an excellent dual vascular supply to the anterior maxillary segment is maintained by preservation of both palatal and labiobuccal soft-tissue pedicles. A modification of the technique facilitates multiple osteotomies through vertical labiobuccal mucosal incisions for closure of multiple interdental diastemas.2 Technically, however, it is more difficult to gain accessto the superior and palatal aspects of the anterior maxilla. As a result, the actual osteotomies in these areas, which are performed in a relatively blind fashion, may be more problematic than the Wunderer or Cupar techniques when significant superior or posterior movement is planned. Surgical
technique
A vertical incision is made through the gingiva in the interdental space immediately anterior to the distal bony margin of the planned ostectomy (Fig. 3, A). As the incision is carried superiorly into the depth of the vestibule, it is directed slightly anteriorly, so that the line of wound closure is positioned over bone. The posterior margin of the incision is raised with an elevator to expose the lateral maxilla ; the antero-inferior margin remains attached to the underlying bone. By subperiosteal tunneling beneath the anterosuperior margin of the incision, the lateral-inferior portion of the bony anterior nasal aperture is visualized. A vertical incision is made through the mucoperiosteum overlying the anterior nasal spine and carried inferiorly 3 or 4 mm. above the free gingival margin. The wound margins are raised and retracted to expose the anterior nasal spine and the superior aspect of the previously raised mucoperiosteal flaps. A periosteal elevator is positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the nasal mucosa when the subapical bone cuts are made. After the first premolar teeth in the planned ostectomy sites are extracted,
330
Bell
Oral March,
Surg. 1977
Big. 3. A, Buccal ostectomy of lateral maxilla through retracted wound margins; periosteal elevator positioned between the nasal mucosa and the lateral wall of the nasal cavity to protect the nasal mucosa when the subapical bone cut is made. B, Transpalatal ostectomy made through buccal ostectomy site. C, Excision of midpalatal bone facilitated by midpalatal sagittal mucosal incision. D, Separation of nasal septum from superior part of maxilla with osteotome. E and F, Interincisal osteotomy accomplished with fissure burr and osteotome through midline retracted wound margins.
Volume Number
43 3
Anterior
ma.xillary
osteotomy
331
the proposed bone cuts are etched in the lateral aspect of the maxilla with a fine fissure burr. A measured vertical section of alveolar bone is excised with a fissure burr or oscillating saw down to the junction of the horizontal and vertical parts of the maxilla. The forefinger is positioned on the palatal mucosa to determine when the palatal bone is sectioned by the burr or saw blade (Fig. 3, B) . Next, the buccal bone incision is carried 3 or 4 mm. above the adjacent canine apex and then angled medially to the inferolateral part of the piriform rim (Fig. 3, A). Finally, the wound is packed with Surgicel or gauze for hemostasisand a similar procedure is carried out on the opposite side. The lateral palatal and transpalatal ostectomies are completed through the vertical ostectomy sites. After a subperiosteal tunnel is developed in the area of the planned palatal ostectomy, the palatal bone is sectioned transversely from the vertical ostectomy site of one side to the contralateral vertical ostectomy site. Digital pressure on the palatal mucosa is essential to make this relatively blind cut without traumatizing the palatal and nasal mucosa. The transverse palatal bone incision can be facilitated by a midpalatal sagittal mucosal incision immediately distal to the incisive foramen (Fig. 3, C) , The thicker midpalatal bone is then excised through the retracted wound margins. Through the wound margins of the vertical midline incision over the anterior nasal spine, the mucoperiosteum is elevated from the anterior nasal floor and nasal septum to facilitate separation of the anterior maxillary segment from the cartilaginous septum (Fig. 3, E) . A notched septal osteotome, which is positioned above the anterior nasal spine and parallel with the hard palate, is malletted between the anterior parts of the nasal septum and maxilla. The anterior maxilla is then mobilized with posterior and inferior digital pressure. A prefabricated acrylic wafer splint, made from the sectioned articulated study casts, is used as an index for determining when the segment is positioned properly. The bony areas on either the proximal or distal segments,which prevent the anterior maxillary segment from being positioned properly, are excised with fine fissure burrs. When interincisal osteotomy or ostectomy is indicated to increase or decrease the intercanine width, improve the canine-premolar relationship, or close an interincisal diastema, the anterior maxillary segment is sectioned through the labial or palatal mucosal incisions (Fig. 3, E and F) . After the superior part of the anterior maxilla is sectioned midsagittally with a fissure burr, the segment is split by malletting a fine sharp osteotome between the sectioned fragments into the interradicular area. Complete mobility and separation of the segments is attained by manipulating an osteotome positioned in the interradicular area of the sectioned fragments. With the two segments distracted, the indicated interdental bone sculpturing is accomplished. SUMMARY
The excellent accessibility and visibility afforded by the Le Fort I “downfracturing” technique for simultaneous anterior and posterior maxillary osteotomies has in recent years obviated the need for many isolated anterior maxillary osteotomies. This procedure with its many modifications7 gives the surgeon consider-
332
Bell
Oral March,
Surg. 1977
ably more latitude in correcting the anteroposterior, vertical, and horizontal manifestations of maxillary excess than has been possible with previously used anterior maxillary osteotomy techniques. Nevertheless, with proper planning, execution, and follow-up care, the anterior maxilla can be moved into a stable relationship with the mandible.8 Complete mobility, preservation of viability by proper design of the bony and soft-tissue incisions,g and adequate fixation during the healing phase are essential to obtain this objective. The technical problems in planning and design for the necessary bony and soft-tissue incisions for three basic anterior maxillary osteotomy techniques are discussed and illustrated. REFERENCES 1. Cohn-Stock,
2. 2 5. 6. 7. 8. 9.
G. : Die Chirurgische Immediatregulierung der Kiefer, Speziell die Chirurgische Behandlung der Prognathie, Vjschr. Zahnheilk., Berlin 37: 320, 1921. Wassmund, M. : Frakturen und Luxationen des Gesichtsschadels, Berlin, 1927. Spanier, F.: Prognathie-Operationen, Z. Zahnarztl. Orthop., Munchen 24: 76, 1932. Cupar, I.: Die chirurgisehe Behandlung der Formund Stellungsveranderungen des Oberkiefers, Ost. Z. Stomatol. 51: 565, 1954; Buss. SC. Cons. Acad. R. P. F. Yougosl. 2: 60, 1955. Wunderer, S. : Erfahrungen mit der Operativen Behandlung Hochgradiger Prognathien, Dtsch. Zahn-Mund-Kieferheilkd. 39: 451, 1963. Eoker. B. N.: Personal communication. Bill, %. H.: Le Fort I Osteotomy for Correction of Maxillary Deformities, J. Oral Surg. 33(6) : 412-426, 1975. Bell. W. H.. and Dann. J. J.: Correction of Dento-Facial Deformities bv Surgerv v ” in the Anterior Part of the Jaws, Am. J. Orthod. 64(2): 162-187, 1973. Bell, W. H.: Biologic Basis for Maxillary Osteotomies, Am. J. Phys. Anthropol. 38(2): 279-289, 1973.
Reprint
requests
to:
Dr. William H. Bell Division of Oral Surgery Department of Surgery Center for Correction of Dento-facial University of Texas Health Science 5323 Harry Hines Blvd. Dallas, Texas 75235
Abnormalities Center