- Email: [email protected]
Considerations for orthognathic surgery during growth, Part 2: Maxillary deformities
CLINICAL REVIEW
C
E
Considerations for orthognathic surgery during growth, Part 2: Maxillary deformities Larry M. Wolford, DMD,a Spiro C. Karras, DDS,b and Pushkar Mehra, DMDc Dallas, Tex The growing patient can present to the clinician with significant dentofacial deformities that require surgical correction. In some cases, certain functional, esthetic, and psychosocial factors may necessitate early surgical intervention. Although there is extensive literature on the effects and stability of orthognathic surgical correction of maxillary deformities in adults, the same is not true for the pediatric and adolescent growing patient. Not much is known about the predictability of orthognathic surgical procedures performed during growth or the effects such procedures have on subsequent facial growth. There is always the possibility that secondary corrective procedures may be required after the initial corrective surgery. This article presents recommendations based on available research and personal clinical experience in surgical correction of maxillary deformities in growing patients. The common maxillary dentofacial deformities, age considerations, and surgical alternatives and sequencing are presented. The treatment of mandibular deformities is addressed in Part 1 of this article. (Am J Orthod Dentofacial Orthop 2001;119:102-5)
S
urgical management of the growing patient remains controversial. The published literature has little to say on the appropriate timing of various maxillary surgical procedures in growing patients or the effects of surgery on postoperative maxillary growth. Growing patients can present to the clinician with maxillary dentofacial deformities that require combined surgical and orthodontic correction. An understanding of normal facial growth is invaluable in properly managing growing patients with maxillary deformities. Around 12 years of age, most transverse maxillary growth is complete.1 Anteroposterior (AP) growth of the maxilla is basically complete by about the age of 14 years.2-8 Normal vertical maxillary growth, however, continues into adulthood.2,6,8 Serial clinical, radiographic, and dental model analyses are very helpful in determining the rate and direction of facial growth. Accurate diagnosis, proper treatment planning, and appropriate age sequencing of procedures are important steps in achieving quality out-
From the Baylor University Medical Center and the Department of Oral and Maxillofacial Surgery, Baylor College of Dentistry, Texas A & M University System, Dallas, Tex. aClinical Professor of Oral and Maxillofacial Surgery and in Private Practice. bFormer Fellow in Oral and Maxillofacial Surgery and currently in Private Practice, Chicago, Ill. cFellow in Oral and Maxillofacial Surgery. Reprint requests to: Larry M. Wolford, 3409 Worth Street, Suite 400, Sammons Tower, Dallas, TX 75246. Submitted, February 2000; revised and accepted, May 2000. Copyright © 2001 by the American Association of Orthodontists. 0889-5406/2001/$35.00 + 0 8/1/111400 doi:10.1067/mod.2001.111400
102
comes for orthognathic surgery in growing patients. Coexisting mandibular deformities, dental ankylosis, and temporomandibular joint (TMJ) pathosis must also be assessed and properly managed. This article, Part 2, outlines our recommendations for combined surgical-orthodontic management of the growing patient with dentofacial deformities. In Part 1, we reviewed management of patients with mandibular deformities. In this part we present common maxillary dentofacial deformities and considerations for surgical management of these deformities in the growing patient who has normal mandibular growth and no dental ankylosis or TMJ pathosis. We will also present recommendations for correction of combined maxillomandibular deformities with double-jaw surgery in growing patients. MAXILLARY DEFORMITIES Maxillary hypoplasia
Maxillary hypoplasia is defined as deficient maxillary development in the AP, transverse, and/or vertical dimensions. Because the cause of this deformity is deficient maxillary growth, normal growth cannot be expected after surgery. Correction of AP or vertical deficiencies during growth will result in recurrence of the Class III skeletal relationship as the mandible continues to grow normally. Earlier surgery may be indicated if significant functional, esthetic, and psychosocial impairments exist. When treating these cases during growth, the surgeon may choose to overcorrect the maxilla and allow the growing mandible to develop
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
A
B Fig 1. Le Fort I osteotomy with segmentalization allows repositioning of the maxilla in all 3 planes of space. A, Maxillary step osteotomy modification. B, Rigid fixation and grafting areas of bone gaps with autogenous or synthetic bone grafts (shown as positions a, b, and c), is the most predictable method for stabilization of the Le Fort I osteotomy.
into it. If surgery is performed during growth, the patient and parents must be informed that future surgery will probably be necessary. Treatment modalities
Le Fort I maxillary osteotomy. The Le Fort I osteotomy (Fig 1), when performed during growth, effectively inhibits further anterior growth of the maxilla.9,10 Vertical maxillary growth, however, can be
Wolford, Karras, and Mehra 103
Fig 2. Horseshoe osteotomy maintains attachment of horizontal palate to vomer and lateral nasal walls. Only the dentoalveolus is mobilized.
expected to continue postoperatively at the same rate as before surgery.10-13 The use of rigid fixation and appropriate grafting with either porous block hydroxyapatite (Interpore 200; Interpore International, Irvine, Calif) or autogenous bone will maximize the quality of the surgical outcome for all types of maxillary osteotomies. Horseshoe maxillary osteotomy (dentoalveolar osteotomy). With the horseshoe maxillary osteotomy procedure (Fig 2), the nasal septum remains attached to the stable palate, and only the dentoalveolar structures are mobilized.14 Thus, some AP maxillary growth may be expected to occur postoperatively. The overall growth rate, however, will remain deficient and result in the redevelopment of a skeletal Class III deformity. No studies are available on growth after maxillary dentoalveolar osteotomies for this type of deformity. The maxillary dentoalveolar osteotomy is technically much more difficult to perform in this patient type. For both of the techniques described here, the most predictable outcome can be expected if performed near to or after the completion of mandibular growth (approximately age 15 for girls; age 17 or 18 for boys). Serial lateral cephalograms are helpful in documenting cessation of mandibular growth. Severe functional or psychosocial factors may indicate earlier treatment. Either procedure can be performed before the patient reaches age 10, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and apply rigid fixation. Although vertical maxillary growth is generally unaffected by this procedure, damage to developing tooth roots may result in dento-osseous ankylosis and localized dentoalveolar growth impairment.
104 Wolford, Karras, and Mehra
Surgically assisted rapid palatal expansion. Surgically assisted rapid palatal expansion usually involves Le Fort I osteotomies without mobilization of the maxilla. It is a useful procedure in cases where the deficiency exists in the transverse dimension only. There are no studies available regarding growth after this procedure. In fact, this procedure may be contraindicated in most growing patients because the midpalatine suture has not normally closed, thus, the less invasive nonsurgical orthodontic/orthopedic expansion is possible. Moreover, postoperative AP maxillary growth may be inhibited by this procedure if the nasal septum is separated from the palatal bone. This procedure is rarely indicated in patients who are less than 15 years of age, but it can technically be done after complete root development and full eruption of the teeth adjacent to the vertical interdental osteotomy. Maxillary protrusion
Maxillary protrusion is defined as excessive AP growth of the maxilla, resulting in a Class II skeletal relationship. No studies exist on facial growth after surgery in growing patients. Postsurgical growth may be dependent on the procedure selected to correct the deformity, as discussed next. Treatment modalities
Le Fort I maxillary osteotomy. The Le Fort I osteotomy (Fig 1), when performed during growth, effectively inhibits further anterior growth of the maxilla, while allowing vertical maxillary growth to continue at the same rate.9-13 With normal mandibular and vertical maxillary growth present, a Class III skeletal and occlusal relationship may develop after surgery. Horseshoe maxillary osteotomy (dentoalveolar osteotomy). With the horseshoe maxillary osteotomy (Fig 2), the nasal septum remains attached to the hard palate; therefore, AP maxillary growth may not be inhibited as it is with the Le Fort I osteotomy.14 Although no postsurgical growth studies have been performed on this type of patient, this may be the technique of choice for maxillary repositioning in the growing patient with AP maxillary hyperplasia. It may offer the best potential for continued AP maxillary growth after surgery. It is recommended that neither procedure be performed before the age of 15 in girls and 17 to 18 in boys, particularly if normal or deficient vertical maxillary growth is present. The effects of these procedures on subsequent growth for this deformity have not been studied. However, better postsurgical growth may be expected with the horseshoe osteotomy. Patients with coexisting vertical maxillary excess can be treated at an earlier age with either technique (see section on vertical
American Journal of Orthodontics and Dentofacial Orthopedics February 2001
maxillary hyperplasia). In cases with severe functional or psychosocial problems, the procedures can be performed when the patient is 8 or 9 years old, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and fixate the maxilla in its new position. Damage to developing tooth roots may result in dento-osseous ankylosis and localized dentoalveolar growth impairment. Vertical maxillary hyperplasia
Also known as vertical maxillary excess, vertical maxillary hyperplasia is defined as an excessive vertical growth of the maxilla and may or may not include an anterior open bite deformity. This deformity can be corrected during growth with predictable results. Vertical maxillary growth can be expected to continue postoperatively at the same rate as before surgery.10-14 While the maxilla continues to grow downward after surgery and the mandible continues to grow at a normal rate, the postoperative occlusal result should be maintained. The vector of facial growth will continue to be downward and backward. AP maxillary growth cannot be expected after surgery if a Le Fort I osteotomy is used, but it may be preserved with a horseshoe osteotomy. Treatment modalities
Le Fort I maxillary osteotomy. Although the Le Fort I maxillary osteotomy (Fig 1) inhibits further anterior growth of the maxilla,9,10 patients with vertical maxillary hyperplasia can expect postoperative vertical maxillary growth to continue at the same rate as before surgery. In patients with normal mandibular growth, the occlusion should remain stable.10-13 Horseshoe maxillary osteotomy (dentoalveolar osteotomy). AP maxillary growth may not be inhibited as significantly with the horseshoe osteotomy technique (Fig 2) compared with the Le Fort I osteotomy. Vertical maxillary growth remains unaffected and continues at the same rate as before surgery.10-13 The most predictable results will be obtained if surgery is performed after age 14 in girls and age 16 in boys. If done at an earlier age (12 years in girls and 14 years in boys), there is a possibility of the excessive vertical maxillary growth rate recreating a vertical maxillary excess after surgery, although to a lesser extent than would occur if surgery was not performed. The occlusion will usually remain stable. Mogavero et al10 demonstrated harmonious growth between the jaw structures when surgery was performed at a younger age. The horseshoe osteotomy, by keeping the nasal septum attached to the horizontal palatal plate, may allow some AP maxillary growth. However, this has not been clinically studied with rigid fixation. Either maxil-
Wolford, Karras, and Mehra 105
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
lary procedure can be performed before the patient reaches age 10, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and apply fixation. Damage to developing tooth roots may result in dento-osseous ankylosis, and localized dentoalveolar growth impairment. Double-jaw orthognathic surgery
Maxillary and mandibular procedures can sometimes be combined and performed during growth with predictable growth after surgery. Orthognathic surgery for the correction of vertical maxillary hyperplasia can be performed with corrective mandibular surgery for retrognathia or prognathism, if the preoperative rate of mandibular growth is normal, and the TMJs are healthy.10 The Le Fort I osteotomy will inhibit further AP maxillary growth while allowing vertical maxillary growth to continue. In cases involving mandibular prognathism secondary to active condylar hyperplasia, surgery involving high condylectomy will arrest the pathologic growth and can be combined with maxillary and mandibular osteotomies with predictable results, regardless of the rate of maxillary growth.14 The high condylectomies should be performed first, and the articular disk should be repositioned over the remaining condylar head. This is followed by routine doublejaw surgery, as planned preoperatively. When properly performed, the high condylectomies prevent further AP growth of the mandible. In the presence of vertical maxillary excess, the vector of facial growth will be downward and backward. Surgical treatment of other combinations of deformities may not be predictable and should be performed after cessation of growth. CONCLUSIONS
The type of facial deformity present and the specific growth vectors of the patient will affect the surgical outcome and must be carefully assessed before surgery. The patient and family must understand the expected results, potential risks, and possible complications that can occur as a result of early surgical intervention. Factors such as the presence of disproportionate mandibular growth (excessive or deficient) and coexisting TMJ pathosis can significantly affect postsurgical growth and treatment outcomes and must be identified and treated appropriately. Some basic considerations that must be kept in mind while contemplating surgical correction of maxillary dentofacial deformities in the growing patient include: 1. Early surgical correction may be beneficial in some patients for functional, esthetic, and psychosocial reasons.
2. The TMJs must be functionally healthy and stable for predictable surgical results. 3. The Le Fort I osteotomy eliminates further AP growth of the maxilla. 4. Surgical correction of vertical maxillary hyperplasia with normal mandibular growth can be predictably performed during growth. Postsurgically, the vector of facial growth will be in a downward and backward direction. 5. Double-jaw surgery may be predictably performed in selected instances for specific jaw deformities. The material presented in this article should serve as a guide for management of maxillary dentofacial deformities in the growing patient who requires corrective orthognathic surgery. These recommendations are in no way meant to be hard and fast rules; each patient should be diagnosed and treated individually with a tailored orthodontic and surgical treatment plan. REFERENCES 1. Björk A, Skieller V. Growth of the maxilla in three dimensions as revealed radiographically by the implant method. Br J Orthod 1977;4:53-64. 2. Savara BS, Singh IJ. Norms of size and annual increments of seven anatomical measures of maxillae in boys from three to sixteen years of age. Angle Orthod 1968;38:104-20. 3. Sillman JH. Dimensional changes of the dental arches: longitudinal study from birth to twenty-five years. Am J Orthod 1964;5 0:824-42. 4. Björk A. Facial growth in man studied with the aid of metallic implants. Acta Odontol Scand 1955;13:9-34. 5. Scott JH. The analysis of facial growth from fetal life to adulthood. Angle Orthod 1963;33:110-3. 6. Singh IJ, Savara BS. Norms of size and annual increments of seven anatomical measures of maxillae in girls from three to seventeen years of age. Angle Orthod 1968;36:312-24. 7. Björk A, Skieller V. Facial development and tooth eruptions: an implant study at the age of puberty. Am J Orthod 1972;62:339-83. 8. O’Reilly MT. A longitudinal growth study: maxillary length at puberty in females. Angle Orthod 1979;49:234-58. 9. Friehofer HP. Results of osteotomies of the facial skeleton in adolesence. J Maxillofac Surg 1977;5:267-97. 10. Mogavero FJ, Buschang PH, Wolford LM. Orthognathic surgery effects on maxillary growth in patients with vertical maxillary excess. Am J Orthod Dentofacial Orthop 1997;111:288-96. 11. Epker BN, Schendel SA, Washburn M. Effects of early surgical superior repositioning of the maxilla on subsequent growth: III, biomechanical considerations. In: McNamara JA, Carlson DS, Ribbens KA, editors. The effect of surgical intervention on craniofacial growth. Ann Arbor: University of Michigan; 1982. p. 231-50. 12. Washburn MC, Schendel SA, Epker BN. Superior repositioning of the maxilla during growth. J Oral Maxillofac Surg 1982; 40:142-9. 13. Vig KW, Turvey TA. Surgical correction of vertical maxillary excess during adolescence. Int J Adult Orthodon Orthognath Surg 1989;4:110-28. 14. Epker BN, Wolford LM. Dentofacial deformities: surgicalorthodontic correction. St. Louis: CV Mosby; 1980.
C
E
Considerations for orthognathic surgery during growth, Part 2: Maxillary deformities Larry M. Wolford, DMD,a Spiro C. Karras, DDS,b and Pushkar Mehra, DMDc Dallas, Tex The growing patient can present to the clinician with significant dentofacial deformities that require surgical correction. In some cases, certain functional, esthetic, and psychosocial factors may necessitate early surgical intervention. Although there is extensive literature on the effects and stability of orthognathic surgical correction of maxillary deformities in adults, the same is not true for the pediatric and adolescent growing patient. Not much is known about the predictability of orthognathic surgical procedures performed during growth or the effects such procedures have on subsequent facial growth. There is always the possibility that secondary corrective procedures may be required after the initial corrective surgery. This article presents recommendations based on available research and personal clinical experience in surgical correction of maxillary deformities in growing patients. The common maxillary dentofacial deformities, age considerations, and surgical alternatives and sequencing are presented. The treatment of mandibular deformities is addressed in Part 1 of this article. (Am J Orthod Dentofacial Orthop 2001;119:102-5)
S
urgical management of the growing patient remains controversial. The published literature has little to say on the appropriate timing of various maxillary surgical procedures in growing patients or the effects of surgery on postoperative maxillary growth. Growing patients can present to the clinician with maxillary dentofacial deformities that require combined surgical and orthodontic correction. An understanding of normal facial growth is invaluable in properly managing growing patients with maxillary deformities. Around 12 years of age, most transverse maxillary growth is complete.1 Anteroposterior (AP) growth of the maxilla is basically complete by about the age of 14 years.2-8 Normal vertical maxillary growth, however, continues into adulthood.2,6,8 Serial clinical, radiographic, and dental model analyses are very helpful in determining the rate and direction of facial growth. Accurate diagnosis, proper treatment planning, and appropriate age sequencing of procedures are important steps in achieving quality out-
From the Baylor University Medical Center and the Department of Oral and Maxillofacial Surgery, Baylor College of Dentistry, Texas A & M University System, Dallas, Tex. aClinical Professor of Oral and Maxillofacial Surgery and in Private Practice. bFormer Fellow in Oral and Maxillofacial Surgery and currently in Private Practice, Chicago, Ill. cFellow in Oral and Maxillofacial Surgery. Reprint requests to: Larry M. Wolford, 3409 Worth Street, Suite 400, Sammons Tower, Dallas, TX 75246. Submitted, February 2000; revised and accepted, May 2000. Copyright © 2001 by the American Association of Orthodontists. 0889-5406/2001/$35.00 + 0 8/1/111400 doi:10.1067/mod.2001.111400
102
comes for orthognathic surgery in growing patients. Coexisting mandibular deformities, dental ankylosis, and temporomandibular joint (TMJ) pathosis must also be assessed and properly managed. This article, Part 2, outlines our recommendations for combined surgical-orthodontic management of the growing patient with dentofacial deformities. In Part 1, we reviewed management of patients with mandibular deformities. In this part we present common maxillary dentofacial deformities and considerations for surgical management of these deformities in the growing patient who has normal mandibular growth and no dental ankylosis or TMJ pathosis. We will also present recommendations for correction of combined maxillomandibular deformities with double-jaw surgery in growing patients. MAXILLARY DEFORMITIES Maxillary hypoplasia
Maxillary hypoplasia is defined as deficient maxillary development in the AP, transverse, and/or vertical dimensions. Because the cause of this deformity is deficient maxillary growth, normal growth cannot be expected after surgery. Correction of AP or vertical deficiencies during growth will result in recurrence of the Class III skeletal relationship as the mandible continues to grow normally. Earlier surgery may be indicated if significant functional, esthetic, and psychosocial impairments exist. When treating these cases during growth, the surgeon may choose to overcorrect the maxilla and allow the growing mandible to develop
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
A
B Fig 1. Le Fort I osteotomy with segmentalization allows repositioning of the maxilla in all 3 planes of space. A, Maxillary step osteotomy modification. B, Rigid fixation and grafting areas of bone gaps with autogenous or synthetic bone grafts (shown as positions a, b, and c), is the most predictable method for stabilization of the Le Fort I osteotomy.
into it. If surgery is performed during growth, the patient and parents must be informed that future surgery will probably be necessary. Treatment modalities
Le Fort I maxillary osteotomy. The Le Fort I osteotomy (Fig 1), when performed during growth, effectively inhibits further anterior growth of the maxilla.9,10 Vertical maxillary growth, however, can be
Wolford, Karras, and Mehra 103
Fig 2. Horseshoe osteotomy maintains attachment of horizontal palate to vomer and lateral nasal walls. Only the dentoalveolus is mobilized.
expected to continue postoperatively at the same rate as before surgery.10-13 The use of rigid fixation and appropriate grafting with either porous block hydroxyapatite (Interpore 200; Interpore International, Irvine, Calif) or autogenous bone will maximize the quality of the surgical outcome for all types of maxillary osteotomies. Horseshoe maxillary osteotomy (dentoalveolar osteotomy). With the horseshoe maxillary osteotomy procedure (Fig 2), the nasal septum remains attached to the stable palate, and only the dentoalveolar structures are mobilized.14 Thus, some AP maxillary growth may be expected to occur postoperatively. The overall growth rate, however, will remain deficient and result in the redevelopment of a skeletal Class III deformity. No studies are available on growth after maxillary dentoalveolar osteotomies for this type of deformity. The maxillary dentoalveolar osteotomy is technically much more difficult to perform in this patient type. For both of the techniques described here, the most predictable outcome can be expected if performed near to or after the completion of mandibular growth (approximately age 15 for girls; age 17 or 18 for boys). Serial lateral cephalograms are helpful in documenting cessation of mandibular growth. Severe functional or psychosocial factors may indicate earlier treatment. Either procedure can be performed before the patient reaches age 10, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and apply rigid fixation. Although vertical maxillary growth is generally unaffected by this procedure, damage to developing tooth roots may result in dento-osseous ankylosis and localized dentoalveolar growth impairment.
104 Wolford, Karras, and Mehra
Surgically assisted rapid palatal expansion. Surgically assisted rapid palatal expansion usually involves Le Fort I osteotomies without mobilization of the maxilla. It is a useful procedure in cases where the deficiency exists in the transverse dimension only. There are no studies available regarding growth after this procedure. In fact, this procedure may be contraindicated in most growing patients because the midpalatine suture has not normally closed, thus, the less invasive nonsurgical orthodontic/orthopedic expansion is possible. Moreover, postoperative AP maxillary growth may be inhibited by this procedure if the nasal septum is separated from the palatal bone. This procedure is rarely indicated in patients who are less than 15 years of age, but it can technically be done after complete root development and full eruption of the teeth adjacent to the vertical interdental osteotomy. Maxillary protrusion
Maxillary protrusion is defined as excessive AP growth of the maxilla, resulting in a Class II skeletal relationship. No studies exist on facial growth after surgery in growing patients. Postsurgical growth may be dependent on the procedure selected to correct the deformity, as discussed next. Treatment modalities
Le Fort I maxillary osteotomy. The Le Fort I osteotomy (Fig 1), when performed during growth, effectively inhibits further anterior growth of the maxilla, while allowing vertical maxillary growth to continue at the same rate.9-13 With normal mandibular and vertical maxillary growth present, a Class III skeletal and occlusal relationship may develop after surgery. Horseshoe maxillary osteotomy (dentoalveolar osteotomy). With the horseshoe maxillary osteotomy (Fig 2), the nasal septum remains attached to the hard palate; therefore, AP maxillary growth may not be inhibited as it is with the Le Fort I osteotomy.14 Although no postsurgical growth studies have been performed on this type of patient, this may be the technique of choice for maxillary repositioning in the growing patient with AP maxillary hyperplasia. It may offer the best potential for continued AP maxillary growth after surgery. It is recommended that neither procedure be performed before the age of 15 in girls and 17 to 18 in boys, particularly if normal or deficient vertical maxillary growth is present. The effects of these procedures on subsequent growth for this deformity have not been studied. However, better postsurgical growth may be expected with the horseshoe osteotomy. Patients with coexisting vertical maxillary excess can be treated at an earlier age with either technique (see section on vertical
American Journal of Orthodontics and Dentofacial Orthopedics February 2001
maxillary hyperplasia). In cases with severe functional or psychosocial problems, the procedures can be performed when the patient is 8 or 9 years old, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and fixate the maxilla in its new position. Damage to developing tooth roots may result in dento-osseous ankylosis and localized dentoalveolar growth impairment. Vertical maxillary hyperplasia
Also known as vertical maxillary excess, vertical maxillary hyperplasia is defined as an excessive vertical growth of the maxilla and may or may not include an anterior open bite deformity. This deformity can be corrected during growth with predictable results. Vertical maxillary growth can be expected to continue postoperatively at the same rate as before surgery.10-14 While the maxilla continues to grow downward after surgery and the mandible continues to grow at a normal rate, the postoperative occlusal result should be maintained. The vector of facial growth will continue to be downward and backward. AP maxillary growth cannot be expected after surgery if a Le Fort I osteotomy is used, but it may be preserved with a horseshoe osteotomy. Treatment modalities
Le Fort I maxillary osteotomy. Although the Le Fort I maxillary osteotomy (Fig 1) inhibits further anterior growth of the maxilla,9,10 patients with vertical maxillary hyperplasia can expect postoperative vertical maxillary growth to continue at the same rate as before surgery. In patients with normal mandibular growth, the occlusion should remain stable.10-13 Horseshoe maxillary osteotomy (dentoalveolar osteotomy). AP maxillary growth may not be inhibited as significantly with the horseshoe osteotomy technique (Fig 2) compared with the Le Fort I osteotomy. Vertical maxillary growth remains unaffected and continues at the same rate as before surgery.10-13 The most predictable results will be obtained if surgery is performed after age 14 in girls and age 16 in boys. If done at an earlier age (12 years in girls and 14 years in boys), there is a possibility of the excessive vertical maxillary growth rate recreating a vertical maxillary excess after surgery, although to a lesser extent than would occur if surgery was not performed. The occlusion will usually remain stable. Mogavero et al10 demonstrated harmonious growth between the jaw structures when surgery was performed at a younger age. The horseshoe osteotomy, by keeping the nasal septum attached to the horizontal palatal plate, may allow some AP maxillary growth. However, this has not been clinically studied with rigid fixation. Either maxil-
Wolford, Karras, and Mehra 105
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
lary procedure can be performed before the patient reaches age 10, provided sufficient space exists above the apices of the developing permanent teeth to place the osteotomies and apply fixation. Damage to developing tooth roots may result in dento-osseous ankylosis, and localized dentoalveolar growth impairment. Double-jaw orthognathic surgery
Maxillary and mandibular procedures can sometimes be combined and performed during growth with predictable growth after surgery. Orthognathic surgery for the correction of vertical maxillary hyperplasia can be performed with corrective mandibular surgery for retrognathia or prognathism, if the preoperative rate of mandibular growth is normal, and the TMJs are healthy.10 The Le Fort I osteotomy will inhibit further AP maxillary growth while allowing vertical maxillary growth to continue. In cases involving mandibular prognathism secondary to active condylar hyperplasia, surgery involving high condylectomy will arrest the pathologic growth and can be combined with maxillary and mandibular osteotomies with predictable results, regardless of the rate of maxillary growth.14 The high condylectomies should be performed first, and the articular disk should be repositioned over the remaining condylar head. This is followed by routine doublejaw surgery, as planned preoperatively. When properly performed, the high condylectomies prevent further AP growth of the mandible. In the presence of vertical maxillary excess, the vector of facial growth will be downward and backward. Surgical treatment of other combinations of deformities may not be predictable and should be performed after cessation of growth. CONCLUSIONS
The type of facial deformity present and the specific growth vectors of the patient will affect the surgical outcome and must be carefully assessed before surgery. The patient and family must understand the expected results, potential risks, and possible complications that can occur as a result of early surgical intervention. Factors such as the presence of disproportionate mandibular growth (excessive or deficient) and coexisting TMJ pathosis can significantly affect postsurgical growth and treatment outcomes and must be identified and treated appropriately. Some basic considerations that must be kept in mind while contemplating surgical correction of maxillary dentofacial deformities in the growing patient include: 1. Early surgical correction may be beneficial in some patients for functional, esthetic, and psychosocial reasons.
2. The TMJs must be functionally healthy and stable for predictable surgical results. 3. The Le Fort I osteotomy eliminates further AP growth of the maxilla. 4. Surgical correction of vertical maxillary hyperplasia with normal mandibular growth can be predictably performed during growth. Postsurgically, the vector of facial growth will be in a downward and backward direction. 5. Double-jaw surgery may be predictably performed in selected instances for specific jaw deformities. The material presented in this article should serve as a guide for management of maxillary dentofacial deformities in the growing patient who requires corrective orthognathic surgery. These recommendations are in no way meant to be hard and fast rules; each patient should be diagnosed and treated individually with a tailored orthodontic and surgical treatment plan. REFERENCES 1. Björk A, Skieller V. Growth of the maxilla in three dimensions as revealed radiographically by the implant method. Br J Orthod 1977;4:53-64. 2. Savara BS, Singh IJ. Norms of size and annual increments of seven anatomical measures of maxillae in boys from three to sixteen years of age. Angle Orthod 1968;38:104-20. 3. Sillman JH. Dimensional changes of the dental arches: longitudinal study from birth to twenty-five years. Am J Orthod 1964;5 0:824-42. 4. Björk A. Facial growth in man studied with the aid of metallic implants. Acta Odontol Scand 1955;13:9-34. 5. Scott JH. The analysis of facial growth from fetal life to adulthood. Angle Orthod 1963;33:110-3. 6. Singh IJ, Savara BS. Norms of size and annual increments of seven anatomical measures of maxillae in girls from three to seventeen years of age. Angle Orthod 1968;36:312-24. 7. Björk A, Skieller V. Facial development and tooth eruptions: an implant study at the age of puberty. Am J Orthod 1972;62:339-83. 8. O’Reilly MT. A longitudinal growth study: maxillary length at puberty in females. Angle Orthod 1979;49:234-58. 9. Friehofer HP. Results of osteotomies of the facial skeleton in adolesence. J Maxillofac Surg 1977;5:267-97. 10. Mogavero FJ, Buschang PH, Wolford LM. Orthognathic surgery effects on maxillary growth in patients with vertical maxillary excess. Am J Orthod Dentofacial Orthop 1997;111:288-96. 11. Epker BN, Schendel SA, Washburn M. Effects of early surgical superior repositioning of the maxilla on subsequent growth: III, biomechanical considerations. In: McNamara JA, Carlson DS, Ribbens KA, editors. The effect of surgical intervention on craniofacial growth. Ann Arbor: University of Michigan; 1982. p. 231-50. 12. Washburn MC, Schendel SA, Epker BN. Superior repositioning of the maxilla during growth. J Oral Maxillofac Surg 1982; 40:142-9. 13. Vig KW, Turvey TA. Surgical correction of vertical maxillary excess during adolescence. Int J Adult Orthodon Orthognath Surg 1989;4:110-28. 14. Epker BN, Wolford LM. Dentofacial deformities: surgicalorthodontic correction. St. Louis: CV Mosby; 1980.