Facial keys to orthodontic diagnosis and treatment planning. Part I

Transcription

1 299 Facial keys to orthodontic diagnosis and treatment planning. Part I G. William Arnett, DDS and Robert T. Bergman, DDS, MS Santa Barbara, Calif. The purpose of this article is twofold (1) to present an organized, comprehensive clinical facial analysis and (2) to discuss the soft tissue changes associated with orthodontic and surgical treatments of malocclusion. Facial examination leads to avoidance of potential orthodontic and surgical facial balance decline and enhances diagnosis, treatment planning, treatment, and quality of results. Patients are examined in natural head position, centric relation, and relaxed lip posture. Nineteen key facial traits are analyzed. By examining the patient in this format, reliable facial-skeletal traits can be recorded that enhance all aspects of care. Orthodontics and surgery used to correct the bite alter facial traits; alteration should reverse negative traits and maintain positive traits. This cannot be achieved without a complete understanding of the face before treatment. Tooth movement (orthodontic or surgical) used to correct the bite can negatively impact facial esthetics, especially if pretreatment esthetics are not defined before treatment. Treating the bite based on model analysis or on osseous cephalometric standards without examination of the face is not adequate. Three questions are asked regarding the 19 facial traits before treatment: (1) What is the quality of the existing facial traits? (2) How will orthodontic tooth movement to correct the bite affect the existing traits (positively or negatively)? (3) How will surgical bone movement to correct the bite affect the existing traits (positively or negatively)? This article is for orthodontists, and yet, much surgical information is included. This is intentional. We only treat what we are educated to see. The more we see, the better the treatment we render our patients. (AM J ORTHOD DENTOFAC ORTHOP 1993;103: ) Diagnosis, treatment planning, and treatment execution are the steps involved in successful care of malocclusions. Diagnosis is the definition of the problem. Treatment planning is based on diagnosis and is the process of planning changes needed to eliminate the problems. Treatment is execution of the plan. The treatment planning of facial esthetic changes is difficult, especially in terms of integrating this with bite correction. Unfortunately, correction of the bite does not always lead to correction, or even maintenance, of facial esthetics. At times, in the zeal to correct the bite, facial balance decline may occur. Part of this problem may be due to lack of attention to esthetics or simply a lack of understanding of what is desirable as an esthetic goal. A person's ability to recognize a beautiful face is innate, but translating this into defined treatment goals is problematic. Recognizing beauty is not practiced nor is it difficult. The perception of beauty is an individual preference with cultural bias. Rules governing why a face is beautiful are not understood nor are required for anyone to say that a face is beautiful. Artists and health professionals have attempted to define and recreate an ideal. They recognize beauty, yet objective standards are difficult, despite unending attempts to clarify this concept. As health professionals have increased their ability to change faces, the necessity to understand what is and is not beautiful has intensified. With the advent of cephalometric headfilms, various analyses were developed in an attempt to qualitate and quantitate esthetic facial profiles. Downs attempted to use hard tissue

2 300 measurements to analyze profile imbalance to differentiate between good and poor dentofacial profiles.1 Several lines and angles have been used to evaluate soft tissue facial esthetics. The H- angle is formed by a line tangent to the chin and upper lip with the NB line.2 Holdaway said the ideal face has an H-angle of 7 to 15, which is dictated by the patient's skeletal convexity.2 The E-line, as described by Ricketts,3 describes the ideal position of the lower lip as two millimeters behind the E-line. Ricketts also described soft tissue by relating beauty to mathematics. The divine proportion was used by the ancient Greeks (ratio of 1.0 to 1.618) and was applied by Ricketts to describe optimal facial esthetics. Merrifield4 said the Z-angle measurement and profile line provides an accurate critical description of the lower face relationship. The Z-angle is the angle formed by the Frankfort plane and a profile line formed by touching the chin and the most procumbent lip. A patient with normal FMA, IMPA, FMIA, and ANB measurements usually has a Z-angle of 80 as an adult and 78 as a child 11 to 15 years of age.4 Scheideman, Bell, et al.5 studied the anteroposterior points on the soft tissue profile below the nose. They dropped a true vertical plane from the natural head position through subnasale and measured lip and chin relationships to this line. They also assessed vertical soft tissue relationships of the face. Worms and others6-8 discussed lip assessment for proportionality, interlabial gap, lower face height, upper lip length, and lower lip length. Another measurement used to study the soft tissue is the angle of convexity described by Legan and Burstone.8,9 This is the angle formed by the soft tissue glabella, subnasale, and soft tissue pogonion.8,9 The zero meridian line, developed by Gonzales-Ulloa,10 is a line perpendicular to the Frankfort horizontal, passing through the nasion soft tissue to measure the position of the chin. The chin should lie on this line or just short of it. The Steiner esthetic plane11 and the Riedel plane12 have also been used to describe the facial profile. The Powell analysis,13 which is made up of the nasofrontal angle, nasofacial angle, nasomental angle, and mentocervical angle, has been developed to give insight into an ideal facial profile. It is widely accepted that orthodontic tooth movement can alter esthetics. As orthodontists have tried to describe beauty, they have also attempted to predict how orthodontic tooth movement affects existing facial balance. Orthodontists have suggested that occlusion and facial beauty are interdependent.1,11,14 It is theorized that when teeth are straightened and the occlusion is corrected to osseous cephalometric standards, optimal facial esthetics will result.1,11,15 Case16 believed the facial outline should be regarded as an important guide in determining treatment when correcting a malocclusion. He recommended extraction of teeth to retract procumbent lips. Angle17 related esthetics to the position of the maxillary incisor. In evaluating facial beauty, Tweed15 concentrated on the position and inclination of the mandibular incisors in relation to the basal bone. As a standard, lateral cephalometric headfilms have been used to diagnose, treatment plan and predict hard tissue and soft tissue responses to orthodontic treatment.1,11,15 Particularly important, cephalometric normative values have been identified that guide diagnosis and tooth movement decisions.1,11,15,18-20 The cephalometric analysis has been used as the standard because of the ease of procuring, measuring, and comparing (superimposition) hard tissue structures and the belief that treating to cephalometric hard tissue norms results in a pleasing face. These perceived advantages of cephalometric analysis have led to heavy reliance on cephalometry in all aspects of orthodontic treatment.

3 301 Clinical facial examination has been subordinate to cephalometric examination in treatment planning. Unlike cephalometry, procuring, measuring, and comparing changes is difficult with facial examination. Normative values are available but they are not used to guide diagnosis and tooth movement decisions as clearly as cephalometric values. This has led to some de-emphasis of clinical examination in orthodontic treatment planning. Unfortunately, reliance on cephalometric analysis and treatment planning sometimes leads to esthetic problems.2,6,21,22-25 Many possible explanations exist for the inadequacy of cephalometry. The assumption that bite correction, based on cephalometric standards, leads to correct facial esthetics is not always true and may, in some instances, lead to less than desirable facial outcomes.2,6,21-26 The soft tissue covering the teeth and bone can vary so greatly that the dentoskeletal pattern may be inadequate in evaluating facial disharmony.7-9 When there is an imbalance in the lip tissue thickness, facial disharmonies may be observed in the absence of dentoskeletal disharmonies. Facial imbalance may be associated with lip inadequacy or lip redundancy caused by lip length, underlying tissues being out of balance, or a problem in tissue thickness or tone.9 Hambleton,27 in his article on the soft tissue covering of the skeletal face, states that the facial curtain is more than just the underlying bone, it is also made up of muscles, fatty tissue, nerves, and blood vessels. Burstone9 presented the idea that correcting the dental discrepancy does not necessarily treat the facial imbalance and may even cause facial disharmonies. Drobocky28 studied 160 four first premolar extraction patients and concluded that "Ten to 15 percent of cases could be defined as excessively flat (dished-in) after treatment." Park and Burstone23 studied 30 cases in which the lower incisor was 1.5 mm anterior to the A- Pog line. This relationship is proposed by some orthodontists as the key to an esthetic profile. The profiles of these 30 patients were found to be grossly different therefore casting doubt on the reliability of the incisor-to-a-pog line as a reliable esthetic guideline. Another source of cephalometric inadequacy in facial diagnosis and treatment planning is the cranial base. When the cranial base is used as the reference line to measure the facial profile, bogus findings can be generated. Michiels24 studied 27 nonorthodontic, Class I patients to test the validity of various popular cephalometric measurements used to predict clinical profiles. His conclusions were that (1) measurements involving cranial base landmarks are inaccurate in defining the actual clinical profile; (2) measurements involving intrajaw relationships were slightly more accurate in reflecting the true profile; (3) no measurement is 100% accurate; and (4) the soft tissue thickness and axial inclination of incisors are the most important variables in inaccuracy. Another source of cephalometric problems is that each cephalometric study examines different measurements as being the key to diagnosis. Therefore, when different cephalometric analyses are used to examine the same patient, different diagnoses, treatment plans, and results can be generated. This disparity makes treatment planning based totally on cephalometry illadvised. Wylie21 analyzed 10 patients using five popular cephalometric analyses and found only 40% agreement on treatment planning. He concluded that "cephalometrics should not be the primary diagnostic tool for dentofacial diagnosis." Wylie's patient population had skeletal malocclusions. Perhaps cephalometrics are more reliable as a predictor of tissue changes when no skeletal disharmonies are present. Many cephalometric norms have been based on patient populations that had no skeletal disharmonies. When these "normal values" from normal populations are applied to anterioposterior and vertical skeletal disharmonies they lose validity. It is unclear if the absence of skeletal malocclusions would improve the agreement among the

4 302 various cephalometric studies. It may be that there is simply no consistence of deformity if different measurements are used. Further problems with cephalometric diagnosis relate to the anatomic areas studied. Facial analyses developed with cephalometric x-ray films, such as those by Holdaway,2,25 Merrifield,4 Burstone,9 and others,1,11,12,14,15 focused primarily on anterioposterior orthodontically alterable dimensions of the face. Complete analysis requires incorporation of vertical and transverse assessment of bite and facial needs. Few orthodontic analyses have used transverse facial analysis because of the reliance on lateral (P-A) head films in diagnosis and treatment planning. Some look at vertical disparities, whereas others do not. Still another problem with cephalometric diagnosis and treatment planning is that the norms may not be accurate because of different soft tissue posturing. In some studies, the soft tissues were not in a repose position when measurements were made.1,9,12,14,15,29,30 This is particularly disruptive in the vertical dimension. Vertical skeletal diagnosis depends on assessment of the soft tissues in repose. Because early studies examined the patient in the closed lip position, reliable norms for relaxed lip position may be lacking. Closed lip position may be useful when no skeletal deformity exists, but in the case of skeletal deformity the closed lip posture is not accurate in terms of diagnosis and treatment planning. The last problem concerning cephalometric diagnosis is based on specialty. Cosmetic changes created with surgical techniques require focus on areas which enhance surgical results. Burstone7,9 and others1,11,12,14,15,19 noted that nose length, lip length, and nasolabial angle are important aspects of facial esthetics, but they, and others, have not specifically oriented the examination to surgical diagnosis and treatment planning. Diagnosis and treatment planning, which are based on model analysis, are less predictable than predicting facial changes on a cephalometric basis. When bite changes, based on model assessment, are the only determinant of treatment, the facial result can be negative. Despite this, Han et al.31 reported that 54.9% of treatment decisions in his study were based on models and no other diagnostic information. This indicates that facial change was not a factor in treatment planning for some orthodontists in Han's study. Models are essential for study of space requirements, arch form, and interarch relationships. They do not shed light on existing and therefore anticipated facial changes. Models, cephalometrics and facial analysis together should provide the cornerstones of successful diagnosis. Models and/or clinical bite examination indicate to the practitioner that bite correction is necessary. Facial analysis should be used to identify positive and negative facial traits and therefore how the bite should be corrected to optimize facial change needs. This article presents analyses of 19 key facial traits as an adjunctive treatment planning tool used to produce improved facial and dental results. Comprehensive facial trait analysis should be used to enhance diagnosis, treatment planning, and quality of results for both surgical and nonsurgical patients. In addition, this method provides a tool for organization, understanding, and communication between the orthodontist, maxillofacial surgeon, and patient. With this analysis, cosmetic problems can be optimally corrected and orthodontic tooth movements that produce esthetic decline can be avoided. With this system, the predictability of facial results should be much better than just with cephalometric treatment and/or model guidelines. In many instances, the facial examination reveals cosmetic problems that indicate skeletal disharmony and the need for surgery. In addition, this system can identify cosmetic-

5 303 skeletal disharmonies that preclude successful orthodontic correction. If the skeletal problem is significant enough to alter facial trait balance, it may be too severe to be corrected successfully with orthodontic tooth movement alone. With the analysis, ideal occlusal harmony is achieved in all cases with desired cosmetic changes dictating whether orthodontic or surgical procedures are used to achieve ideal occlusion. If orthodontic tooth movement will not produce necessary facial changes, then surgery is indicated. This decision is made without cephalometric numbers. In this system, the cephalometric x-ray film is not used for diagnosis, but rather as an aid to try treatment options in the form of visual treatment objectives (VTO).32 The purpose of the VTO is to assess how tooth and bone movement used to correct the bite will impact the face. Frequently, different procedures will achieve the same corrected occlusion. Avoiding unwanted facial change and obtaining desired cosmetic changes dictates which treatment is used. An example of this is correcting a Class II occlusion with either a LeFort I impaction, mandibular advancement, or upper first premolar extractions with headgear and Class II elastics. All three treatments correct the bite but change the face in different ways. The procedure selected should balance the face optimally. Facial examination can determine the best treatment for achieving facial balance, whereas cephalometric analysis has been shown to be unreliable.2,6,7,9,21-25,33,34 When attention is directed only to bite correction, facial balance may not improve and can deteriorate. The orthodontist's job is to balance occlusal correction, temporomandibular joint function, periodonal health, stability, and facial balance while moving the teeth to correct the bite. METHODS An analysis of facial cosmetics was devised based on key landmarks relevant to optimal orthodontic and surgical-orthodontic treatment. Areas of examination were used for diagnosis, orthodontic treatment planning (extraction patterns), and surgical treatment planning. The cephalometric x-ray film was not used for diagnosis of skeletal problems, but was used to test facial examination data by a variant of the VTO (visual treatment objective) process.32 The most important point in proper analysis of facial esthetics is the use of a clinical format. Examination should not be based on static laboratory x-ray film and photographic representation of the patient alone. Cephalometric x-ray films and photographs may improperly position the patient's head orientation, condyle position, and lip posture. This can lead to inaccurate diagnosis, treatment planning, and treatment. These variables can be controlled by the doctor during clinical examination of the patient, as opposed to the lack of control found with commercial laboratories, dental assistants, or laboratory technicians. This is not to say that commercial records are not part of the permanent record, but the clinically controlled, reliable, doctor-verified record is imperative to ensuring accuracy. Natural head posture, centric relation (uppermost condyle position),35 and relaxed lip posture can be assessed and maintained in the office so that valid examination data can be collected. By examining the patient in this format, reliable facial-skeletal data can be obtained that enhances diagnosis, treatment planning, treatment, and quality of results. Natural head posture is preferred because of its demonstrated accuracy over intracranial landmarks. Natural head posture has a 2 standard deviation compared with a 4 to 6 standard deviation for the various intracranial landmarks in use.36,37

6 304 Natural head posture36 is the head orientation the patient assumes naturally (Fig. 1, A). Patients do not carry their heads with the Frankfort horizontal parallel to the floor.1 Therefore this landmark should not dictate head posture used for treatment planning. A leveled, flat Frankfort horizontal (Fig. 1, B) creates a Class III profile (chin protrusion) with cephalometric values consistent with upper incisor flaring and lower incisor retraction. A leveled, steep Frankfort horizontal (Fig. 1, C) creates a Class II profile (chin retrusion) with cephalometric values consistent with upper incisor retraction and lower incisor flaring. Skeletal changes made based on these inappropriate skeletal orientations will look good on the head film but not when the patient assumes natural head posture. When skeletal changes are made relative to natural head position appropriateness is ensured in the resulting soft tissue profile.1 All examination data should be recorded in centric relation since orthodontic and surgical results are strictly in this position to produce precise function. Centric relation, as used in this article, is the uppermost position described by Dawson.35 If head films are taken in a postured position, all interarch relationships are incorrect. Posturing of the mandible can decrease the severity of Class II (Fig. 2) and increase the severity of Class III relationships (Fig. 3). Models may indicate and clarify the true mandibular position, but patients can also posture during model wax bite fabrication. The only direct evidence of posturing is tomographic representation of the condyle on the eminence rather than in the glenoid fossa. Unfortunately, tomograms are not taken as a routine diagnostic aid in the orthodontic nor surgical work-up. Centric relation can be established as follows: 1. Patient in a 45 sitting position. 2. Use a warmed, double-thickness piece of pink base plate wax. 3. Guide the opening and closing to first tooth contact, nondeflected position. 4. Trim the wax bite to the buccal surfaces of the teeth. 5. Repeat step three. 6. Wash the wax bite in cold water. 7. Repeat step 3. Guided closure consists of gentle manipulation of the chin in the direction of the arc of closure and does not involve more than gentle pressure in a posterior direction. Closure is stopped at the first tooth contact because deflections of the mandible start at that point and alter skeletal (chin) and lower incisor midline structures during facial analysis. The wax bite is used for head films, tomograms, model mounting, and facial analysis. This ensures consistency of data and treatment results. This positioning of the condyles has been shown consistent with the Roth power centric on mandibular position indicator (MPI) and tomographic study. The technique described previously should be reliable on symptom-free, resolved TMJ patients. The relaxed lip position is obtained while the patient is in centric relation by the following method7: 1. Ask the patient to relax.

7 Stroke the lips gently. 3. Take multiple measurements on different occasions. 4. Use casual observation while the patient is unaware of being observed. This method ensures soft tissue diagnosis accuracy. Surgical plans derived from these measurements will be correct. The patient should be in the relaxed lip position because it demonstrates the soft tissue, relative to hard tissue, without muscular compensation for dentoskeletal abnormalities. Vertical disharmony between lip lengths and skeletal height (vertical maxillary excess, vertical maxillary deficiency, mandibular protrusion, mandibular retrusion with deep bite) can not be assessed without the relaxed lip posture. Existing positions and needed changes in upper incisor exposure, interlabial gap, lip length, and proportion are lost in the closed lip position. Closed lip position may be adequate for normoskeletal cases but is totally inadequate for skeletal disharmony assessment (Figs. 4 and 5). When the lips contact (distortion), the bite should be opened (Fig. 4, B) by placing a wax bite between the teeth until the lips separate in the repose posture. By using this open bite posturing, lip length and position distortion is avoided. Soft tissue cosmetic problems can then be assessed relative to needed bite changes. With the natural head posture, centric relation, and relaxed lip position, the patient is visualized in all three planes of space: 1. Anterior-posterior 2. Transverse 3. Vertical Key traits chosen for this facial examination were those that lead to superior orthodontic as well as surgical results. Two factors were important in regard to how this examination was formulated: 1. The specific traits that were selected for inclusion. 2. The normative values for the selected traits. As with cephalometrics, there are hundreds of facial soft tissue traits that have been studied. This examination consists of 19 of these traits. Inclusion of a trait within the study was dependent on the high significance of the trait to successful orthodontic and surgical facial outcomes. Examination of key traits in three planes of space was necessary. The normal values are a combination of previous studies (Table I) and 20 years of surgical experience. The use of surgical experience to assess existing and needed changes of the face is, at best, suspect but art is a necessary part of facial beauty. There is also a problem with using normative values. The original facial studies,7-9,18,29,30,38 identified different normative values and did not study all the significant traits. An example of the variability is the nasolabial angle (Table I). Burstone7 reports a range of 73.8 plus or minus 8, Legan8 102 plus or minus 8, Farkas plus or minus 8.7 (female), UMKC to 116.7, and Lehman plus or minus 8. Many reasons exist for the inconsistency between different study norms (Table II), including the following:

8 Different racial origins within the study populations. 2. Some studies contained malocclusions, whereas some studies had normal bites or Class I occlusions only. 3. Some studies were in closed lip positions, whereas others were in relaxed lip position. 4. Some studies used head films oriented to cranial base structures, others were in natural head position. 5. Some values were from clinical measurement, although most were from cephalometric x-ray films. 6. The exact way of measuring the same trait may be different from one study to the next. 7. Some studies contained patients who were not fully grown. With the discrepancy of norms, each patient being examined should be studied with norms appropriate to that patient (race, age, lip posture, head orientation). Norms should be used for guidance but not as absolute guidelines for changes. By asking the following three questions, the best treatment plan becomes apparent: 1. What is the quality (good or bad) of the existing facial traits? 2. How will the orthodontic tooth movement to correct the bite affect the existing traits (positively or negatively)? If orthodontic tooth movement necessary for bite correction results in unacceptable facial balance decline, surgery is indicated to avoid this negative facial outcome (i.e., opening the nasolabial angle with upper premolar extractions, headgear and Class II elastics). 3. When surgery is necessary, which surgery (maxilla, mandible, or both) will be necessary to normalize negative and maintain positive facial traits while correcting the bite? The ideal treatment plan must be formulated that affects the facial traits in the most positive fashion, while correcting the bite. The treatment plan should be orthodontic or surgical orthodontic as determined by facial examination. Orthodontic tooth movement may satisfy bite and facial correction or surgery of one or both jaws may be necessary. Four possible treatments exist for each patient: (1) orthodontics alone, (2) orthodontics plus lower jaw surgery, (3) orthodontics plus upper jaw surgery and (4) orthodontics plus both upper and lower jaw surgery. The treatment that optimizes occlusion (bite and TMJ harmony), facial balance, stability, and periodontal health is chosen. If treatment harms the patient, it should not be rendered. References: 1. Downs WB. Analysis of the dentofacial profile. Angle Orthod 1956;26: Holdaway RA. A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part I. AM J ORTHOD 1983;84(1): Ricketts RM. Esthetics, environment and the law of lip relation. AM J ORTHOD 1968;54:

9 Merrifield LL. The profile line as an aid in critically evaluating facial esthetics. AM J ORTHOD 1966;52: Scheideman GB, Bell WH, Legan HL, Finn RA, Reisch JS. Cephalometric analysis of dentofacial normals. AM J ORTHOD 1980;78(4): Worms FW, Spiedel TM, Bevis RR, Waite DE. Posttreatment stability and esthetics of orthognathic surgery. Angle Orthod 1980;50(4): Burstone CJ. Lip posture and its significance in treatment planning. AM J ORTHOD 1967;53: Legan HL, Burstone CJ. Soft tissue cephalometric analysis for orthognathic surgery. J Oral Surg 1980;38: Burstone CJ. The integumental profile. AM J ORTHOD 1958;44: Gonzales-Ulloa M, Stevens E. The role of chin correction in profile plasty. Plast Reconstr Surg 1961;36: Steiner CC. Cephalometrics in clinical practice. Angle Orthod 1959:29: Riedel RA. An analysis of dentofacial relationships. AM J ORTHOD 1957;43: Powell N, Humphreys B. Proportions of the esthetic face. New York: Thieme-Stratton, Tweed CH. Indications for extraction of teeth in orthodontic procedure. AM J ORTHOD ORAL SURG 1944;30: Tweed CH. Frankfort mandibular incisor angles in diagnosis, treatment planning and prognosis. Angle Orthod 1954;24: Case CA. A practical treatise on the techniques and principles of dental orthopedia and prosthetic correction of cleft palate. 2nd ed. Chicago: CS Case, Angle EH. Malocclusion of the teeth. 7th ed. Philadelphia: SS White Dental Manufacturing, Broadbent BH Sr, Broadbent GH Jr, Golden WH. Bolton standards of dentofacial developmental growth. St Louis: CV Mosby, Ricketts RM, Roth RH, Chaconos SJ, Schulhof RJ, Engle GA. Orthodontic diagnosis planning. Denver: Rocky Mountain Orthodontics, Behrents RG. An atlas of growth in the aging craniofacial skeleton. Monograph 18. Ann Arbor: Center for Human Growth and Development, The University of Michigan Wylie GA, Fish LC, Epker BN. Cephalometrics: a comparison of five analyses currently used in the diagnosis of dentofacial deformities. Int J Adult Orthod Orthog Surg 1987;2(1): Jacobson A. Planning for orthognathic surgery art or science? Int J Adult Orthod Orthog Surg 1990;5(4): Park YC, Burstone CJ. Soft tissue profile falacies of hard tissue standards in treatment planning. AM J ORTHOD DENTOFAC ORTHOP 1986;90(1):52-62.

10 Michiels LYF, Tourne LPM. Nasion true vertical: a proposed method for testing the clinical validity of cephalometric measurements applied to a new cephalometric reference line. Int J Adult Orthod Orthog Surg 1990;5(1): Holdaway RA. A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part II. AM J ORTHOD 1984;85: Talass MF, Baker RC. Soft tissue profile changes resulting from retraction of maxillary incisors. AM J ORTHOD DENTOFAC ORTHOP 1987;91(5): Hambleton RS. The soft tissue covering of the skeletal face as related to orthodontic problems. AM J ORTHOD 1964;50: Drobocky OB, Smith RJ. Changes in facial profile during orthodontic treatment with extraction of four first premolars. AM J ORTHOD DENTOFAC ORTHOP 1989;95(5): Farkas LG. Anthropometry of the head and face in medicine. New York: Elsevier North Holland Inc., Farkas LG, Kolar JC. Anthropometrics and art in the aesthetics of women's faces. Clin Plast Surg 1987;14: Han MK, Vig KWL, Weintraub JA, Vig PS, Kowalski CJ. Consistency of orthodontic treatment decisions relative to diagnostic records. Abstract. AM J ORTHOD DENTOFAC ORTHOP 1991;100(3): Fish LC, Epker BN. Surgical-orthodontic cephalometric prediction tracing. J Clin Orthod 1980;14: Worms FW, Isaacson RJ, Speidel TM. Surgical orthodontic treatment planning: profile analysis and mandibular surgery. Angle Orthod 1976;46(1): Jacobson A. Orthognathic diagnosis using the proportionate template. J Oral Surg 1980;38: Dawson PE. Optimum TMJ condyle position in clinical practice. Int J Periodont Restor Dent 1985;3: Moorrees CFA, Kean MR. Natural head position, a basic consideration in the interpretation of cephalometric radiographs. Am J Phys Anthropol 1958;16: Cooke MS, Wei SHY. The reproducibility of natural head posture: a methodological study. AM J ORTHOD DENTOFAC ORTHOP 1988;93(4): Alizadeh CM, Kirchhoff ST, Masunaga MI, Sekijima RK. Lenard-Burstone cephalometric analysis. Kansas City: University of Missouri at Kansas City, Department of Orthodontics, Lehman JA. Soft-tissue manifestations of the jaws: diagnosis and treatment. Clin Plast Surg 1987;14:

11 309 Fig. 1. Patient with Class I malocclusion. A, When postural horizontal is used to assess facial balance, true facial appearance is seen. Frankfort horizontal does not affect the positioning of the face and therefore surgical or orthodontic decisions. B, The patient's head is oriented to cephalometric Frankfort horizontal. When porion is relatively superior and/or orbitale is inferior, the resulting Frankfort horizontal is flat. When the Frankfort plane is leveled to the floor, the chin is rotated forward and the patient appears Class III. C, The patient's head is oriented to cephalometric Frankfort horizontal. When porion is relatively inferior and/or orbitale is superior, the resulting Frankfort horizontal is steep. When the Frankfort plane is leveled to the floor, the chin is rotated back and the patient appears Class ll. Fig. 2. Patient with Class II malocclusion with condyles in different positions. A, With the condyle seated in the uppermost fossa position, the Class II skeletal pattern is apparent, revealing a possible need for surgical lengthening of the mandible. B, The same Class II mandibular retrusion with the mandible postured forward. (If the cephalometric x-ray films are postured incorrectly, models and/or tomograms may indicate the true bite position.) Laboratory cephalometric x-ray films can miss the Class II skeletal relationship because of forward posturing of the lower jaw during x-ray procurement. An incorrect, nonsurgical diagnosis and treatment plan can result from this mandibular posturing error.

12 310 Fig. 3. Patient with Class III malocclusion with condyles in different positions. A, A patient with Class III malocclusion with condyles seated in the uppermost fossa position. B, Some patients with Class III malocclusions posture the lower jaw forward when the teeth hit edge to edge. (If the cephalometric x-ray films are postured incorrectly, models and/or tomograms may indicate the true bite position.) The anterior posturing pulls the condyles forward from the uppermost fossa position, which increases the severity of the Class III. This postured condyle position may falsely indicate the need for surgical mandibular setback. Fig. 4. When bite is deep, causing relaxed lips to contact and compress, soft tissue cannot be assessed accurately. The bite should be opened until the lips no longer touch. In this position the true lip length can be measured without lip interference produced by bite overclosure. A wax bite is used to open the bite. A, A patient with deep bite and short lips created by bite overclosure and resulting lip compression. The lip length is normal, but overclosure compresses the lips, shortening their actual length. B, Proper examination of this patient is with the bite open until the lips are no longer in compression. Surgical/orthodontic treatment planning can be accurately performed when the true lip length and posture are revealed by opening the bite. Skeletal movements needed to produce ideal relationships (i.e., upper tooth to lip) can then be planned.

13 Fig. 5. Patient with vertical maxillary excess is depicted. A, When the skeletal length is long, the lips need to be assessed in the relaxed position. This position reveals skeletal and soft tissue drape disharmony. B, When the skeletal length is long, the closed lip position masks the true relationship of the skeletal structures and lips. No accurate plans can be made from the closed lip position when skeletal disharmony exists. 311

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