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ORTHOdontics PGII/III ____________________________________________________________________________________________________________ _________ GROWTH MODIFICATION VERSUS ORTHOGNATHIC SURGERY INCLUDES COMPARISONS BETWEEN POTENTIAL OF THESE MODES OF: MAXILLOFACIAL ORTHOPEDICS AND DISCUSSION OF HAZARDS AND LIMITATIONS OF ORTHOGNATHIC SURGERY ____________________________________________________________________________________________________________ _________ FACULTY: Joseph Ghafari , DMD. Goals: This series of lectures should enable the resident to: 1. Understand how growth modification in the growing child, and orthognathic surgery in the adult, represent the end components of maxillofacial orthopedics. 2. Recognize the potential and limitations of both modalities. 3. Understand hazards related to orthognathic surgery. Objectives: The resident should know: 1. The basic concepts underpinning growth modification and orthognathic surgery. 2. The orthognathic process: athe importance of tooth inclination relative of bone in this process of normalization among teeth and jaws; bthe application of this principle in growth modification and orthognathic surgery; cthe key role of the orthodontist in this process. 3. The scope of constitutional limitation relating to the fact that the nature of a dysmorphology is self-limiting, particularly when it is not confined to one facial feature. 4. That orthognathic surgery, although the favored treatment for many skeleto-dental dysplasias, may not yield an ideal result because of both constitutional and/or therapeutic limitations. 5. That the potential of growth modification in a child should not be discarded on the account of greater bone movement possible with orthognathic surgery at a later adult age. The level of change also depends on the site of change (mandible, chin, lips,…). Decisions are best made on where scientific evidence is available. 6. Specific hazards encountered with orthognathic surgery, associated with surgery proper, or side effects (periodontal complications, relapse, root resorption). ____________________________________________________________________________________________________________ _________ COURSE DURATION AND SCOPE: This course is listed within the Maxillofacial Orthopedics series that also includes Pediatric Orthodontics. The course is scheduled in the Fall of the second year (location of corresponding examination), but is also attended by third or first year residents because its content lends itself to evaluation at different times of the educational maturation. It is given at a 2-hour session on a weekly basis for at least 3 sessions. Preferred precursors to this course are those related to early treatment and orthognathic surgery. POLICY ON EXAMINATIONS: At least 2 biannual examinations (progress and final) are given for all courses, if a course spans the entire year. If classes terminate before the end of a semester, the final examination is given at the semi-annual examination that is closest to the end of the course, unless the course director schedules the final examination earlier. During a course, any number of progress tests or assignments may be given. Their cumulative weight in proportion to the final grade may not exceed 50%. GROWTH MODIFICATION VERSUS ORTHOGNATHIC SURGERY ____________________________________________________________________________________________________________ _________ SUMMARY OUTLINE FOR GM AND OS 1-DIFFERENT LIMITATIONS OF GM AND ORTHODONTICS WITH OS POTENTIALS A- Constitutional limitations Therapeutic limitations AND LIMITATIONS of treatment combining B2- HAZARDS orthodontics and orthognathic surgery ____________________________________________________________________________________________________________ _________ COURSE OUTLINE 1. POTENTIAL AND LIMITATIONS OF GROWTH MODIFICATION AND ORTHOGNATHIC SURGERY Introduction Questions are asked and answers are presented that emerge from the evaluation of research and clinical observations: 1Is the hand of growth in early treatment equal to the hand of the orthognathic surgeon in the adult. Growth modification may forego the need for surgery under certain conditions. Timing and duration of treatment are critical. 2What are the limitations of growth modification and treatment combining orthodontics and orthognathic surgery? AConstitutional limitations that stem from the nature of the dysmorphology, soft tissue anatomy and adaptation, and the direction and amount of bone and tooth movement. The limitations may be related to improper or compromised treatment planning, as well as side effects of surgery and tooth movement. Clinical reports, literature review, and pilot research data, help to emphasize the importance of facial esthetics. Treatment should not be planned based on the skeletal relationships only. Limitations could be minimized in view of available data, in favor of expansion rather than constriction of the facial soft tissue mask. Although orthognathic surgery aims at improving masticatory function and possibly speech, it offers an opportunity to improve esthetics that should not be missed. BTherapeutic limitations, which may be related to improper or compromised treatment planning, direction and amount of tooth movement (dentoalveolar normalization or decompensation) and bone displacement, as well as side effects of surgery and tooth movement. The lecture series emphasizes ways to minimize limitations in view of available scientific data. 1- POTENTIAL OF GROWTH MODIFICATION AND ORTHOGNATHIC SURGERY ABasic Concepts Similarities in goals regarding amount and direction of bone movement Growth modification: Through (orthopedic) forces: -Change in the absolute size of a jaw -Redirection of growth -Differential growth between jaws Orthognathic surgery: Through surgery -Change in the absolute size of a jaw -Redirection of position -Differential positioning of jaws BGrowth modification of the maxilla Growth modification of the maxilla involves procedures that affect maxillary deficiency or excess in all planes of space: maxillary size reduction (headgear), expansion (palatal distraction), or position (retraction or protraction). -Potential for growth modification depends not only on the patient’s age, but also constitutional characteristics of the maxillary complex and its relation to the mandible. -Data analysis from research and clinical sources: 1a longitudinal study of head gear used for 2 years to correct Class II, division 1 malocclusion in prepubertal children (n=36); 2a cross-sectional study of palatal expansion (n=24); 3reports of successful treatment of anterior crossbite and Class III malocclusion with a facial mask. -Results indicate that maxillary growth modification limited by 1factors within the maxilla itself (e.g. maturation of sutures; non-concordance of centers of resistance of maxillary bone and dental components); 2its relation to the mandible (mandibular size dictating maxillary treatment or causing maxillary retrognathism unless the anterior crossbite is treated early); 3function (e.g. mouth breathing). CGrowth modification of the mandible -recognized mostly in the treatment of Class II, division 1 malocclusion. -severe limitations for *restriction of mandibular growth in Class III malocclusion; *mandibular constriction or widening in mandibular transverse problems. -Controversies on effect of growth modification (functional appliance) regarding mandibular forward growth stimulation or enhancement. Tested possibilities: 1. mandible surpasses its growth potential- NO conclusive evidence. 2. mandibular growth is accelerated- Difficult to gauge clinically, although demonstrated in animals. These hypotheses assume that the individual growth potential can be predicted within reasonable accuracy. 3. mandible is merely positioned forward and subsequent growth, if sufficient, adapts (“catches up”) to this position. This hypothesis assumes that (a) occlusal interdigitation plays an important role in maintaining the mandible in the forward position; (b) the most important effect of a functional appliance is the distal force on the maxillary complex. Effect is achieved through forces transferred to maxillary teeth and bone by the appliance DThe orthopedic process -Natural compensation for skeletal disproportion between jaws with dentoalveolar inclinations toward a functional occlusion: in Class II malocclusion, maxillary anterior teeth compensate by retroclining, mandibular incisors by proclination. 1surgery without orthodontics: minimal amount of movement obtained. 2ideally, prior to surgery, orthodontic optimal positioning of teeth over basal bone: dentoalveolar normalization or decompensation. 3Conceptually, as relates to position of the incisors, growth modification and orthognathic surgery are different facets of the same coin. Dentoalveolar normalization, can actually be summed up by getting the teeth out of the way of the surgeon- or growth- to allow for optimal movement of the bones. Working guideline in sagittal plane: achieve at the end of presurgical orthodontic process (or growth process) canine occlusion in Class 1, and optimal inicisal overjet (inclination of maxillary incisors can limit or require modification of surgical movement –or needed amount of growth-, particularly when maxillary or mandibular rotation is part of surgery). 2- LIMITATIONS OF GROWTH MODIFICATION AND ORTHOGNATHIC SURGERY In contrast to growth modification, orthognathic surgery can improve the shape of the chin through genioplasty, but with both modalities, it is difficult to manage the nasolabial relationship when the nose is tipped upward. Factors that limit the achievement of optimal esthetics in maxillofacial orthopedics (growth modifica-tion in growing children, and orthognathic surgery in adults) were evaluated. Findings suggest that the nature of the dysmorphology is self-limiting from therapeutic and esthetic perspectives. 2a- Constitution of patient 1Nature of dysmorphology 2Soft tissue evaluation and adaptation 2b- Treatment 1- Treatment planning 2- Direction and amount of bone and tooth movement 3- Duration of treatment or surgery 4- Stability of results and implications 5- Side effects of tooth movement and surgery A- Limitations of growth modification If growth modification is started early enough, do we get enough expression of differential growth to mirror results of orthognathic surgery? - Research data not available - Issue of practicality and length of treatment - WIDE INDIVIDUAL VARIATION - Incisor inclination: Issue of compensation/decompensation and impact on jaw position BLimitations of orthognathic surgery Limitations of orthognathic treatment are also related to the patient’s constitution or to actual therapeutic limitations. -*Treatment limitations associated with treatment planning; direction and amount of bone and tooth movement; duration of surgery; stability of results and implications; and side effects of surgery and tooth movement. -*-Critical limitations relate to dentoalveolar normalization: position and inclination of maxillary incisors can limit or require modification of surgical movement, particularly when maxillary rotation is planned. -*-Prediction of outcome is also limiting. B1- Prediction of soft tissue changes following orthodontics and orthognathic surgery - wide variation on accuracy of prediction - limitations related to: variability of conditions in the study of treatment outcome; variability in surgery (e.g. procedure, extent of movement [over or under treatment], method of wound closure); variability in anatomy and adaptive potential of soft tissue; interaction in different planes of space (2D vs. 3D) and between different structures; factors of tooth movement and growth. However, trends can be described about overall facial changes and specific features: B1a- General trends 1Horizontal changes more predictable than vertical changes, which vary considerably. -vertical changes smaller in nature, or -vertical hard tissue changes less predictable and less stable than horizontal movements. 2Soft tissue response depends on the type of surgical procedure. B1b- Specific facial features 1Nose: degree of control of nasal changes factor of amount and direction of surgical movement of the maxilla. Predictability of the response is limited. 2Upper lip: - vermilion border cannot be increased with orthognathic surgery (may need adjunctive cosmetic surgery); - lengthening cannot be achieved with orthognathic surgery (unpredictable success through cosmetic procedures); - response to vertical movement maxilla fully predictable (considerable variability). *In response to down movement, upper lip does not shorten; therefore, the amount of bony movement that is needed must be achieved, and should not be undercorrected. *Similar rationale applies to maxillary impaction, which also should not be undercorrected. - response to forward movement: does not follow in a 1:1 ratio. Reasons: possible stretching of lip or incision of the lip. 3Lower lip: most variable of soft tissue landmarks in response to orthognathic movement. 4Chin: -mandibular advancement: the least variable (generally 1:1 ratio). -mandibular set back: a submental fold may occur leading to double chin appearance that would require submental lipectomy. -genioplasty: remarkable to improve esthetics; should not be overdone. Moving chin back is least predictable genioplasty because soft tissue displaces at a ratio of less than 0.5 to 1. Limitations in soft tissue response to movement of underlying hard tissues lead to the consideration of adjunctive cosmetic procedures (e.g. rhinoplasty, cheiloplasty, liposection) to improve facial esthetics. Comparative limitation of treatment between growth modification and surgery (orthognathic and cosmetic) Forehead GM , S Nose tip GM > S B/ST C/ST Surgery (P) Surgery (P) Length of upper lip GM, S ST Surgery?? Thickness of upper lip GM, S ST Surgery (P) Thickness of lower lip GM, S ST Surgery (P) Chin (shape of) GM > S B/ST GM- growth modification S- orthognathic surgery B- bone C- cartilage ST- soft tissue 2. 1- Surgery (S, P) P- plastic surgery HAZARDS AND LIMITATIONS OF TREATMENT COMBINING ORTHODONTICS AND ORTHOGNATHIC SURGERY IMPROPER PLANNING* A- Surgery versus orthodontics - orthodontics without surgery - surgery without orthodontics B- Dentoalveolar compensation over, under (limited) C- Surgery - Amount of movement (Optimal/Compromised) (expansion, advancement, setback, impaction, extrusion) - Asymmetry D- Growth additional growth: amount, duration E- Soft tissue thickness and response 2- SIDE EFFECTS/COMPLICATIONS A- Surgery -surgical technique (healing, complications) -altered position of mandible B- Root resorption C- Periodontal complications D- Relapse REFERENCES PART 1 1. Proffit WR, Fields HW. Orthodontic treatment planning: limitations, controversies, and special problems. In: Contemporary Orthodontics, 3rd ed. Eds, WR Proffit, HW Fields. St. Louis, Mosby. 2000;276-279. 2. Steiner CC. The use of cephalometrics as an aid to planning and assessing orthodontic treatment. Am J Orthod 1960; 46:721-35. 3. Costa LE. “What we see is what they get.” The limitations of growth modification and camouflage treatment. 18th Biennial Growth Seminar, New-Conn Orthodontic Study Group, April 2001. 4. Ghafari J, Shofer FS, Jacobsson-Hunt U, Markowitz DL, Laster LL. Headgear versus function regulator in the early treatment of Class II, Division 1 malocclusion. Am J Orthod Dentofac Orthop 1998; 113:51-61. 5. Moss ML, Salentijn L. The primary role of functional matrices in facial growth. Am J Orthod. 1969; 55:566-77. 6. Ackerman JL, Proffit WR, Sarver DM. The emerging soft tissue paradigm in orthodontic diagnosis and treatment planning. Clin Orthod Res. 1999 May;2(2):49-52. 7. Beckett W. The Story of Painting. DK Publishing, 1994. 8. Etcoff NL. Beauty and the beholder. Nature 1994; 368:186-7. 9. Langlois JH, Roggerman LA Psychol Sci 1990; 1:115-21. 10. Perrett DI, May KA, Yoshikawa S. Facial shape and judgements of female attractiveness. Nature 1994; 368:239-42. 11. Utsugi R. The concepts of shading and individuality in facial attractiveness. Unpublished research, 1996. 12. Rosen HM.Aesthetic perspectives in jaw surgery. New York: Springer-Verlag, Inc. 1999. 13. Ghafari J. Modified use of the Moorrees mesh diagram. Am J Orthod Dentofacc Orthop 1987; 91: 47582. 14. Farkas LG. Anthropometry of the head and face, 2nd ed. New York: Raven Press; 1994. 15. Arnheim R. The face and the mind behind it. In: Esthetics and the treatment of facial form. JA McNamara Jr. (Ed.), Craniofacial Growth Series, Volume 28, Center for Human Growth and Development, The University of Michigan, Ann Arbor, 1993; 1-6. 15. Olds C. Facial beauty in Western art. In: Esthetics and the treatment of facial form. JA McNamara Jr. (Ed.),Craniofacial Growth Series, Volume 28, Center for Human Growth and Development, The University of Michigan, Ann Arbor, 1993; 7-26. 16. Faigin G. The artist’s complete guide to facial expression. New York: Watson-Guptill. 1990;88-123. 17. Sarver DM. The importance of incisor positioning in the esthetic smile: the smile arc. Am J Orthod Dentofacial Orthop 2001; 120-98-111. 18. Ackerman JL, Ackerman MB, Brensinger CM, Landis JR. A morphometric analysis of the posed smile. Clin Orthod Res. 1998;1:2-11. 19. Betts NJ. In Fonseca Oral and Maxillofacial Surgery. Philadelphia: WB Saunders Co 2000; 2: 20. Mobarak KA, Espeland L, Krogstad O, Lyberg T. Soft tissue profile changes following mandibular advancement surgery: predictability and long-term outcome. Am J Orthod Dentofacial Orthop 2000; 119:353-67. 21. Sarver DM. The application of video imaging technology to orthognathic surgery. In Fonseca Oral and Maxillofacial Surgery. Philadelphia: WB Saunders Co 2000; 2:53-6 22. Lee DY, Bailey LJ, Proffit WR. Soft tissue changes after superior repositioning of the maxilla with Le Fort I osteotomy: 5-year follow-up. Int J Adult Orthod Orthognath Surg. 1996;11:301-11. 23. Ghafari J, Baumrind S, Macari A, Shofer A, Laster S, Efstratiadis S. Profile Characteristics Related to the Anatomy of the Chin in a Class II Treatment Population. J Dent Res PART 2 1. Ghafari J. Root resorption associated with orthognathic surgery: Modified definitions of the resorptive process. In: Biological Mechanisms of Tooth Eruption, Resorption, and Replacement by Implants, Z. Davidovitch (ed.), Boston: Harvard Society for the Advancement of Orthodontics, 1995: 545-556. 2. O’Ryan F, Epker BN Deliberate surgical control of mandibular growth. I. A biomechanical theory. Oral Surg Oral Med Oral Pathol. 1982 Jan;53(1):2-18. 1982. 3. Wolford LM, Karras SC, Mehra P. Considerations for orthognathic surgery during growth, part 1: mandibular deformities. Am J Orthod Dentofacial Orthop. 2001 Feb;119(2):95-101 4. Wolford LM, Karras SC, Mehra P. Considerations for orthognathic surgery during growth, part 2: maxillary deformities. Am J Orthod Dentofacial Orthop. 2001;119(2):102-5.. 5. Cassidy DW Jr, Herbosa EG, Rotskoff KS, Johnston LE Jr.. A comparison of surgery and orthodontics in "borderline" adults with Class II, division 1 malocclusions. Am J Orthod Dentofacial Orthop. 1993; 104:455-70.. 6. Lenzen C, Trobisch H, Loch D, Bull HG. Significance of hemodynamic parameters of blood loss in orthognathic surgery. Mund Kiefer Gesichtschir. 1999;3(6):314-9. 7. Praveen K, Narayanan V, Muthusekhar MR, Baig MF. Hypotensive anaesthesia and blood loss in orthognathic surgery: a clinical study. Br J Oral Maxillofac Surg. 2001;39(2):138-40. ADDITIONAL REFERENCES 1. Ackerman JL, Proffit WR. Soft tissue limitations in orthodontics: treatment planning guidelines. Angle Orthod. 1997;67(5):327-36. 2. Arnett GW, Bergman RT. Facial keys to orthodontic diagnosis and treatment planning. Part I. Am J Orthod Dentofacial Orthop. 1993;103(4):299-312. 3. Arnett GW, Bergman RT. Facial keys to orthodontic diagnosis and treatment planning--Part II. Am J Orthod Dentofacial Orthop. 1993;103(5):395-411. 4. Arnett GW. A redefinition of bilateral sagittal osteotomy (BSO) advancement relapse. Am J Orthod Dentofacial Orthop. 1993;104(5):506-15. 5. Arnett GW, Jelic JS, Kim J, Cummings DR, Beress A, Worley CM Jr, Chung B, Bergman R. Soft tissue cephalometric analysis: diagnosis and treatment planning of dentofacial deformity. Am J Orthod Dentofacial Orthop. 1999;116(3):239-53. 6. Bailey LJ, Proffit WR, White R Jr. Assessment of patients for orthognathic surgery. Semin Orthod. 1999 (4): 09-22. 7. Bailey LJ, Duong HL, Proffit WR. Surgical Class III treatment: long-term stability and patient perceptions of treatment outcome. Int J Adult Orthodon Orthognath Surg. 1998;13(1):35-44. 8. Bailey LT, Proffit WR, White RP Jr. Trends in surgical treatment of Class III skeletal relationships. Int J Adult Orthodon Orthognath Surg. 1995;10(2):108-18. 9. Buttke TM, Proffit WR. Referring adult patients for orthodontic treatment. J Am Dent Assoc. 1999; 130(1): 73-9. 10. Cassidy DW Jr, Herbosa EG, Rotskoff KS, Johnston LE Jr. A comparison of surgery and orthodontics in "borderline" adults with Class II, division 1 malocclusions. Am J Orthod Dentofacial Orthop 1993; 104(5): 455-70. 11. Forssell K, Turvey TA, Phillips C, Proffit WR. Superior repositioning of the maxilla combined with mandibular advancement: mandibular RIF improves stability. Am J Orthod Dentofacial Orthop 1992; 102(4): 342-50. 12. Kantor ML, Phillips CL, Proffit WR. Subtraction radiography to assess reproducibility of patient positioning in cephalometrics. Am J Orthod Dentofacial Orthop 1993; 104(4): 350-4. 13. Lee DY, Bailey LJ, Proffit WR. Soft tissue changes after superior repositioning of the maxilla with Le Fort I osteotomy: 5-year follow-up. Int J Adult Orthod Orthognath Surg. 1996; 11: 301-11. 14. Miguel JA, Turvey TA, Phillips C, Proffit WR. Long-term stability of two-jaw surgery for treatment of mandibular deficiency and vertical maxillary excess. Int J Adult Orthod Orthognath Surg 1995; 10(4):23545. 15. Phillips C, Snow MD, Turvey TA, Proffit WR. The effect of orthognathic surgery on head posture. Eur J Orthod 1991; 13(5): 397-403. 16. Phillips C, Medland WH, Fields HW Jr, Proffit WR, White RP Jr. Stability of surgical maxillary expansion. Int J Adult Orthodon Orthognath Surg 1992; 7(3): 139-46. 17. Proffit WR, Turvey TA, Fields HW, Phillips C. The effect of orthognathic surgery on occlusal force. J Oral Maxillofac Surg 1989;47(5): 457-63. 18. Proffit WR, Phillips C. Adaptations in lip posture and pressure following orthognathic surgery. Am J Orthod Dentofacial Orthop 1988; 93(4): 294-302. 19. Proffit WR, Fields HW Jr, Moray LJ. Prevalence of malocclusion and orthodontic treatment need in the United States: estimates from the NHANES III survey. 20. Proffit WR, Turvey TA, Phillips C. Orthognathic surgery: a hierarchy of stability. Int J Adult Orthodon Orthognath Surg 1996; 11(3): 191-204. 21. Proffit WR, Phillips C, Tulloch JF, Medland PH. Surgical versus orthodontic correction of skeletal Class II malocclusion in adolescents: effects and indications. Int J Adult Orthod Orthognath Surg 1992;7:209-20. 22. Proffit WR, Bailey LJ, Phillips C, Turvey TA. Long-term stability of surgical open-bite correction by Le Fort I osteotomy. Angle Orthod 2000; 70(2):112-7. 23. Proffit WR, Miguel JA The duration and sequencing of surgical-orthodontic treatment. Int J Adult Orthod Orthognath Surg 1995;10(1):35-42. 24. Proffit WR, Phillips C, Douvartzidis N. A comparison of outcomes of orthodontic and surgicalorthodontic treatment of Class II malocclusion in adults. Am J Orthod Dentofacial Orthop 1992 Jun; 101(6):556-65. 25. Rosen HM, Ackerman JL. Porous block hydroxyapatite in orthognathic surgery. Angle Orthod 1991 ; 61(3): 185-91; discussion 192. 26. Sarver DM, Ackerman JL. Orthodontics about face: the re-emergence of the esthetic paradigm. Am J Orthod Dentofacial Orthop 2000;117(5):575-6. 27. Schubert P, Bailey LJ, White RP Jr, Proffit WR. Long-term cephalometric changes in untreated adults compared to those treated with orthognathic surgery. Int J Adult Orthod Orthognath Surg 1999;14(2):91-9. 28. Simmons KE, Turvey TA, Phillips C, Proffit WR. Surgical-orthodontic correction of mandibular deficiency: five-year follow-up. Int J Adult Orthodon Orthognath Surg 1992;7(2):67-79 29. Tulloch JF, Phillips C, Proffit WR. Benefit of early Class II treatment: progress report of a two-phase randomized clinical trial. Am J Orthod Dentofacial Orthop 1998;113(1):62-72. 30. Van SickelsJE. Distraction osteogenesis versus orthognathic surgery. Am J Orthod Dentofac Orthop. 2000; 118:482-4. 31. Van Sickels JE, Dolce C, Keeling S, Tiner BD, Clark GM, Rugh JD. Technical factors accounting for stability of a bilateral sagittal split osteotomy advancement: wire osteosynthesis versus rigid fixation. Oral Surg Oral Pathol Oral Radiol Endod 2000; 89:19-23. 32. Van Venrooy JR, Proffit WR. Orthodontic care for medically compromised patients: possibilities and limitations. J Am Dent Assoc 1985 ;111(2):262-6.