Holdaway Vto... Superimpostion

American

Journal

Founded in 1915

of ORTHODONTICS Volume 85 Copyright

Number

4

April, 1984

0 1983 by The C. V. Mosby Company

ORIGINAL

A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part II

ARTICLES

Dr. Holdaway

Reed A. Holdaway Provo, Utah

T

he term visual (or visualized) treatment objective (VTO) was coined to cormmmicate the planning of treatment for any orthodontic problem. Systems based on hard-tissue measurements or reference lines alone may produce disappointing results. It is high time that orthodontists use a method of considering a case from all possible perspectives, such as the limitations of the case, the good aspects of the case, etc. Then, from an understanding of profile soft-tissue responses accompanying tooth movement, we can first develop a lower face profile outline that is harmonious with the skeletal type of the patient under study. Once we have developed that soft-tissue profile objective with an understanding of how the lips respond when the teeth are moved, we can plan the dental repositioning necessary to bring about the desired change. More important, when we have quantitated a soft-tissue profile that is excellent, as the patient is treated we will take great care in our procedures to not do anything that will detract from the physical attractiveness of that person’s face. Before I explain the VT0 steps, the question of how much (and in what manner) a particular patient will grow must be considered. This is where. our careful study of all previously treated cases, as in Part I of this presentation,’ helps us to get the “feel” of a case. I believe that growth-forecasting methods get one much closer to final size and proportion than one can ever get by working only from the pretreatment tracing

with a “static synthesis. ‘Q Of course, a static approach is all that is needed for nongrowing patients. For patients in whom growth is expected, forecasting growth with a visual treatment plan with the input of soft-tissue visualization will be useful. Your own treatment effects on such things as mandibular growth behavior and anchorage conservation must be evaluated in order to increase your VT0 accuracy. My own cases finish active treatment much closer to my VTOs than if a VT0 is done for someone else to follow in treatment. I will present the steps of the VTO, using one case first, and then show various types of cases in which just the denture orientation based on soft tissues will be shown.3 For relatively short treatment periods, sliding the VT0 tracing upward and forward along the basionnasion line is satisfactory. In comparing this approach to the sella-nasion line approach, we find that the midface vertical growth is more accurate when the sellanasion line is used to express forward growth at nasion . This was especially noticeable when growth over a period of 5 years or longer was forecast whereas excessive midface height resulted from use of the basionnasion line. In using the Ricketts facial axis to find the mandibular and soft-tissue chin position, Jacobsen and Sadowsky3 report three times the growth of that at nasion, which is nearly always less than 1 mm per year. If 279

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Am. J. Orthcd. April 1984

Holdaway

Fig. 1. Draw frontonasal area, line SN and line NA.

my observations are correct, usually only 0.66 to 0.75 mm per year occurs, whereas growth on the facial axis is reasonably consistent at 3 mm per year except during growth spurts, especially the pubertal growth spurt, when it may approach twice that amount in some boys. Another variation from the article by Jacobsen and Sadowsky3 involves those cases which at the time of retention will not fall into the best range in the convexity H angle chart, on both the convex and the concave sides. The use of the line to the vermilion border of the upper lip perpendicular to the Frankfort plane plus the variable H angle as skeletal convexity varies should be substituted whenever upper lip curl or overall lip support appears questionable by the usual method. The overall effects of growth and treatment appear more accurate with this simplified technique for growth forecasting when used along with my own understanding of the treatment responses of my own patients. Jacobsen and Sadowsky are correct in their statement: “Growth responses are generally predictable within certain limits and can be measured. The VT0 as described here is based on this philosophy. Newer studies , however, have indicated quite clearly that one cannot rely completely on the constancy of the growth pattern, since increments of facial growth are not

necessarily uniform in either direction or rate. It is recognized that precise prediction of skeletal or soft-tissue growth in amount or direction is beyond our present knowledge. However, until the stage is reached whereby orthodontists and/or scientific investigators are able to accurately predict or determine direction and rates of growth, we have no alternative but to avail ourselves of our present knowledge of growth based on average increments. ” Orthodontic treatment is monitored with progress head films, usually at 6-month intervals. Whenever a case is encountered in which growth is occurring in a different direction than expected, a new midtreatment VT0 is then constructed so that changes in treatment procedures can be made and any disfiguring lip responses can be avoided. Whenever possible, it is a good plan to take head films for a year or two prior to beginning treatment and thus develop a growth profile for the case, assuming that there is an opportunity to examine the patient that early. Developing pretreatment growth profiles of our patients helps to overcome our inadequacies in growth forecasting. There are not more than one or two out of 100 cases in my practice today in which there is dissatisfaction

Volume

85

Number

4

Fig. 2. Express growth in the frontonasal area for the estimated treatment time. Here horizontal growth is expressed in the frontonasal area for the estimated treatment time.

with the final outcome of treatment after final softtissue adaptive changes have occurred, as opposed to one out of five prior to use of the soft-tissue VTO. In addition to the six reference lines presented in Part I for the actual VT0 construction, three more shown in Fig. 1, A (dotted lines) are added to the tracing to facilitate rapid copying of portions of the pretreatment lateral cephalometric tracing. First is the nasion to point A line. In longitudinal growth studies of patients not undergoing orthodontic treatment, the constancy of the angle SNA is extremely good-only about 1” change in 5 years on the average. For l- or 2-year forecasts, we can disregard such a small amount. Reference lines or angles that are very near to constants offer our best chance of constructing visual treatment objectives that we can confidently use as

Soft-tissuecephalometric analysis 281

Fig. 3. Express growth of the mandible in its vertical and anterior growth pattern and draw the anterior portion of the mandible, the soft-tissue chin, and the Downs lower border of the mandible line.

treatment goals and guides during orthodontic treatment. Second is Ricketts’ facial axis (foramen rotundum to gnathion) . This is used as a guide to direction of mandibular growth. Third is the mandibular plane (Downs). Some may prefer to use the Go-Gn line as a lower border of the mandibular reference line. Either is acceptable, but the Downs mandibular plane line is preferred because of its nearness to the actual lower border. The headfilm should be taken with the patient’s lips lightly touching. VT0 STEPS Step I (Fig. 1, B and C)

The first step is to place a clean sheet of tracing material over the original tracing, copying (1) the frontonasal area, both hard- and soft-tissue, with the softtissue nose carried down to near the point where the

282

Holdaway

Fig. 4. Express (or lower face)

growth in a horizontal and draw the posterior

Am. J. Orthod. April 1984

direction in the mandible portion of the mandible.

outline of the nose starts to change directions; (2) the sella-nasion line; and (3) the nasion-point A line. Step 11(Fig. 2)

First, superimpose on the SN line and move the tracing to show expected growth (0.66 to 0.75 mm per year unless a pubertal growth spurt is expected from wrist plate studies). Second, copy the outline of sella. Third, either copy or change the facial axis (Ricketts’ foramen rohmdum to gnathion) as you expect it to behave according to the facial type of the patient and the treatment mechanics that you customarily use in such cases. (The facial axis line is usually opened about l”, but it may even be closed if one is confident that

Fig. 5. Locate and draw lower part of the nose.

the maxilla,

the new

A point,

and the

mandibular growth of the forward rotational type will occur during treatment .) Note: It is important to understand that the prediction of growth at nasion, along the SN line, is actually an overall prediction for all midfacial structures, including the nasal bone, the maxilla, and the soft tissues. Step III (Fig. 3, A and B)

First, superimpose the VT0 facial axis on the original and move the VT0 up so that the VT0 SN line is above the original SN. The amount of movement will usually be 3 mm per year of growth, except in accelerated growth-spurt periods. (Note: Since the facial axis may be opened or closed as judged from the facial

Soft-tissue cephalometric

Volume 85 Number 4

Fig.

6. Locate

and

draw

the occlusal

plane.

pattern, the SN lines will not be parallel if we have changed the facial axis.) Second, copy the anterior portion of the mandible, including the symphysis and anterior half of the lower border. Also draw the soft-tissue chin, eliminating any hypertonicity evident in the mentalis area. (Slightly round out this area.) Third, copy the Downs mandibular plane. Step IV (Fig. 4, A and 8) First, superimpose on the mandibular plane and move the VT0 forward until the original sella and the VT0 sella are in a vertical relation. Next, with the tracing in this position, copy the gonial angle, the posterior border, and the ramus. Finally, superimpose on sella to complete the condyle.

analysis

283

Fig. 7. Draw a new H or harmony line and, using it as a guide, draw the most ideal lip position and form possible for that patient.

Note: At this point total vertical height has been forecast, as has the forward location of the chin structures, both hard and soft, and consideration will have been given to effects of treatment mechanics on vertical dimension. One should not open the facial axis more than 1” to 2” because greater opening than this is usually inconsistent with good treatment mechanics.

Step V (Fig. 5, A and B) First, superimpose the VT0 NA line on the original NA line and move the VT0 up until 40% of the total growth is expressed above the SN line and 60% below the mandible. (Note: This may be varied as you perceive the facial type to be short or long.) Second, with the tracing in this position, copy the

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maxilla and the mandible is expressed 50% above the maxilla and 50% below the mandible. Second, with the tracing in this position, copy the occlusal plan. Note: Ideally, the occlusal plane is located about 3 mm below the lip embrasure. This permits the lower lip to envelop the lower third of the crowns of the upper incisor teeth. If the cant of the occlusal plane is correct, it should be maintained. If not, then it can be altered accordingly at this stage. In cases involving short upper lips, it may not be practical to intrude the upper incisors to this extent, but the vertical relationship of the teeth and gingival tissue will be more esthetically pleasing if we can reach this goal. Step VII (Fig. 7, A and 6)

Fig.

8. Procedure

followed

in drawing

new

lip outlines.

maxilla to include the posterior two thirds of the hard palate, PNS to ANS to 3 mm below ANS. Third, also with the tracing in this same position, complete the nose outline around the tip to the middle of the inferior surface. Note: The vertical growth of the nose over the usual 18 to 24 months of estimated treatment time keeps pace with the growth from the maxilla vertically to the anterior cranial base. Thus, its relationship to ANS is relatively constant. In some cases there may be an elevation of the nasal bone and greater development of the nasal bulk, but this is difficult to predict and thus some noses will have changed form more than this VT0 procedure suggests. Step VI (Fig. 6, A and B) First, with the VT0 still superimposed on the line NA, move the VT0 so that vertical growth between the

Note: When there is a uniform distribution of the soft tissues in the profile and the upper lip is of average length, and where the cant of the H line is not adversely affected by excessive facial convexity or concavity, the depth of the superior sulcus measured to the H line is most ideal at 5 mm. A range of 3 to 7 mm allows one to maintain type with short and/or thin lips and long and/or thick lips. Additional refinement of the technique, which covers all of the above, is gained by use of the vertical line from Frankfort plane to the vermilion border of the upper lip, which is ideal at 3 mm with a range from 1 to 4 mm. To find the point along the lower border of the nose outline at which the new H line will intersect it, both perspectives are used in the exceptional cases just mentioned. First, line up a straight-edge tangent to the chin and angle it back to a point where there is a 3 to 3.5 mm measurement to the superior sulcus outline of the original tracing and draw the H line to this. As one redrapes the superior sulcus area to the new tip of the upper lip point, a 5 mm superior sulcus depth develops almost automatically. If you have trouble with this, the use of the Jacobson-Sadowsky lip-contour template* is recommended . Second, with the tracing still superimposed on the maxilla and line NA and using the occlusal plane (Fig. 8, A and B) as a guide for the lip embrasure, draw the upper lip from the vermilion border to the embrasure. Then from the point on the lower border of the nose where its outline stopped on the VTO, draw in the superior sulcus area. This is a gradual draping to the new vermilion border outline. Third, superimpose on line NA and the occlusal plane, Form the lower lip, remembering that from 1 mm behind the H line to 2 mm anterior can be excellent, depending on variations of thickness of the two *Unitek

Corporation,

Monrovia,

Calif.

Volume 85 Number 4

Fig. 9. Relocate the harmonious position it is a simple matter the anterior teeth to

Soft-tissue

maxillary central incisor. (Once the most and form of the lips have been established, to compute the necessary repositioning of produce them.)

lips. Again, most cases will fall on the H line or within 0.5 mm of it. Finally, complete the inferior sulcus drape from the lower lip to the chin in a form harmonious with the superior sulcus. (Note: The lips are not expected to have fully adapted to this position in more than about one half of the cases at the time of retention.) Step VIII (Fig. 9, A and B) First, with the exceptions noted earlier, lip strain that shows up as excessive upper lip taper is our first consideration. In the case shown in Fig. 9, the basic lip thickness measurement was 15 mm and the thickness at the vermilion border was 10 mm. One millimeter of taper is normal, leaving a lip strain factor of 4 mm. Next we are concerned with how many millimeters

Fig. 10. Reposition this on lower arch

the lower length.

cephalometric

incisor

and calculate

analysis

the effect

205

of

the upper lip is back from its original position. This is measured with the tracings superimposed on line NA and the maxilla. In the present case this also amounts to 4 mm. The third consideration is maxillary incisor “rebound. ’ ’ When the maxillary incisors have been retracted 5 mm or more and the case has been slightly overtreated to a near edge-to-edge incisor overbite and overjet relationship, we can expect about 1.5 mm relapse tendency. Obviously, there will be no tendency to move labially in those cases in which the upper incisor is not retracted or in those cases, such as anterior crossbites and/or Class III cases, in which the maxillary incisors have been expanded labially. Here the incisor retraction is significant, and we will use 1.5 mm for incisor rebound. In this particular patient, then, the

206 Holdaway

Fig. 11. Determine the lower first molar position, considering total arch length discrepancy.

calculations would be as follows: (1) Elimination of lip strain, 4 mm. (2) Upper lip change, 4 mm. (3) Maxillary incisor rebound, 1.5 mm. Finally, with the tracing still superimposed on line NA and the maxilla, place the maxillary incisor template, taking cognizance of the amount that it is to be repositioned (9.5 mm in this case), its axial inclination, and the relationship of the incisal edge to the occlusal plane, and draw the tooth. Step IX (Fig. 10, A and B)

First, superimpose the VT0 on the mandibular plane and symphysis. Using the template, reposition the lower incisor to be in ideal retention occlusion with

Am. J. Orthod. April 1984

Fig. 12. A, Reposition the maxillary first molar. 8, Complete the artwork in the area involving point A, in the anterior portion of the hard palate, and in the lower alveolus lingually and labially.

the maxillary incisor, using the occlusal plane as a guide and by tipping the tooth about the apex unless bodily movement is needed to improve the form of the inferior sulcus area. Second, with the tracing in this same position, measure the amount of lingual movement of the lower incisors. Twice this amount is the arch length loss due to lower incisor (uprighting) lingual tipping or gain from labial tipping when indicated. This loss of arch length is now combined with the arch length discrepancy determined from the model to obtain the total arch length discrepancy. In this case, the calculations would be (1) arch length loss from reposition, 2 X 4 = 8 mm; (2) model discrepancy, 2 mm; (3) total discrepancy, 1Omm.

Soft-tissue cephalometric

Volume 85 Number 4

Fig. 13. Retention and illustrate VT0 steps.

follow-up

tracings

of patient

used

to

Step X (Fig. 11, A and B) With the tracing superimposed on the mandibular plane and symphysis and using the occlusal plane as a vertical guide, draw the lower molar where it must be to eliminate remaining space if extractions must be part of the treatment plan. In the case shown in Fig. 11, each lower molar must be moved forward 2.5 mm. Note: By using the VT0 approach, you will come upon many cases where mesially tipped lower molars can be uprighted to gain all of the model arch length discrepancy when the incisor position is adequate. Distal tipping of lower molars 2.5 mm can allow nonextraction treatment in cases of a model discrepancy of 5 mm. In other cases, especially those having a history of thumb- or lip-sucking or in which serial extraction is

Fig. 14. Pretreatment, case shown in Fig.

retention,

and follow-up

analysis

photographs

287

of

13.

contraindicated, the VT0 will show that the lower incisors need to be moved forward, thus also increasing arch length and reducing the need to extract. On occasion both approaches can be used. In my opinion, lower incisors should not be moved forward to a point more than 1 mm anterior to the A-pogonion line, as posttreatment stability and long-term periodontal health are usually endangered by so doing. The use of the VT0 at this point to study and evaluate anchorage and arch length is one of its great advantages. If the lower molar must be moved anteriorly as much as 3.5 mm, the lower second premolars will be removed. There are cases in which there is an extremely thin alveolar process, particularly those cases that have deficient lower face height where the lower molars seem to get locked up in cortical bone if the second premolars are extracted. Extraction of the

288

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Holdaway

April

Fig. 15. A Class III case for which mandibular setback analysis and VT0 showed that orthodontic treatment

second premolars instead of the first premolars actually increases the lower molar anchorage. When these two factors combine as contraindications to forward lower molar movement, it is sometimes better to look at judicious narrowing of the teeth through stripping and polishing than to extract at all. Step XI (Fig. 12, A)

First, using the occlusal plane and the lower first molar as a guide, with a tooth template, position the upper first molar in ideal Class I occlusion with the lower first molar. Second, superimposing tracings on the original NA line and the outline of the maxilla, evaluate the extent of upper molar movement. In cases that worked out as lower arch nonextraction cases, one may still need to think about other extraction alternatives in the upper arch, such as upper second molars when good third molar buds are developing or upper first premolars. Step XII (Fig. 12, B)

Note: As to how point A changes with incisor retraction, it is imperative that the clinician study the be-

surgery was previously alone was the procedure

1984

advised. The soft-tissue of choice.

fore and after tracings of many cases superimposed on the original NA line and best fit of the maxilla to get the “feel” for this step. Obviously the change in point A is greater when the upper incisor root apices are moved a considerable distance than when the upper incisors are tipped lingually. More change in A point is also evident when the tracing is superimposed in this manner if we are going to use heavier orthopedic forces, especially in younger patients (in the mixed dentition). When completed, the VT0 can be used not only in case analysis and treatment planning, but as we consider movement of the various groups of teeth to correct a malocclusion the mechanical procedures that will be most direct and efficient practially suggest themselves. Mention must also be made of the usefulness of VTOs to monitor treatment from periodic head films. Using all that we think we know about growth and facial types, on occasion we discover that nature has something else in mind and we may need to change the course of our treatment because of an unexpected growth response. As we look at the retention tracing in Fig. 13, A, it is evident that the tooth movement objectives of the

Soft-tissue cephalometric

Volume 85 Number 4

Fig.

16. For legend,

see

Fig. 15.

VT0 were accomplished. The soft-tissue analysis measurements , while greatly improved, still fail to meet the VT0 goals, even though the soft-tissue chin position has improved 1”. This is because the lips still have not completely adapted to the tooth movement. There is an increased measurement of the upper lip thickness at the vermilion border from 10 to 16 mm. The H angle has improved from 23” to 14”. However, with a 2 mm convexity, ideally it should be 12”. In the 7-year follow-up shown in Fig. 13, B, the soft-tissue facial angle is an ideal 90”. The superior sulcus form is excellent to both reference lines. The upper lip has 1 mm of normal taper, with a slight decrease in basic thickness. Skeletal convexity is down to 0, and the H angle is ideal at lo”. The upper lip has completed its adaptive changes and has a 1 mm taper. We see the same changes in this patient’s facial photographs (Fig. 14). ILLUSTRATIVE

CASES

We will show a few cases to illustrate further how the use of the soft-tissue analysis and the VT0 based on the analysis can help us make correct decisions and improve the orthodontic care of our patients. In the first case (Figs. 15, A-C and 16) the patient is a white man, 22 years 5 months of age, with a Class III dental malocclusion. Skeletally, the soft-tissue chin

Fig. 17. A Class II case in which gery was previously advised.

mandibular

analysis

advancement

299

sur-

position at 93.5” to Frankfort plane is not excessively prognathic. The -3 mm convexity measurement is likewise indicative of a Class III tendency, but in the mild range, in spite of models that show more than a half-premolar Class III dental malocclusion. When we look at the soft-tissue profile measurements, we see a superior sulcus depth of 5 mm to the line perpendicular to Frankfort and 7 mm to the H line. These are both adequate measurements for a man with fairly thick and long lips. When we look at the lower lip to the H line, it measures 6 mm anterior to the line. When we look at the lower incisor position in relation to the hard-tissue facial plane, the incisors are 9 mm anterior to the bony chin. In drawing a VT0 in this case, as shown in Fig. 15, B, the upper incisors become the area to disturb as little as possible. One should consider treatment mechanics and their effect on mandibular opening. Vigorous Class III pull will tend to elongate upper buccal segment teeth and hinge the mandible down and back, improving both the convexity and the soft-tissue facial plane angle or mandibular prominence. After 13 months of treatment, the retention tracing (Fig. 15, C) is very close to the treatment plan as seen in the VTO. It is true that the four premolars were extracted, but there is no way that maxillary incisor alignment would have maintained itself without extractions, even if the

290

Am. J. Orthod. April 1984

Holdaway

Fig.

18.

For legend, see Fig. 17.

mandible had been set back surgically. The soft-tissue chin position was always good. The lower incisors and lower lip were the areas in need of help. There was no need for mandibular surgery in this case. Fig. 17, A shows the pretreatment tracing of a young female patient. The profile soft-tissue chin position is 1.5” more prominent than in the Class III case just considered. The treatment challenge in this case is to eliminate the overjet and still have an adequate curl to the upper lip. There is, however, excessive taper to the upper lip or a lip strain factor of 4 mm. The wrist plate and age indicate about 1 year of continued growth, and the mandibular fotm would strongly suggest a very favorable horizontal type of growth. There is a skeletal convexity of 8 mm, but this is nicely compensated by a 16 mm soft-tissue chin thickness. In Fig. 17, B , considering these factors in the VTO, we see the potential for an excellent orthodontic treatment result without mandibular advancement surgery. Certainly, with a 95” soft-tissue facial angle, there was no indication for mandibular advancement in this case. In the retention tracing in Fig. 17, C the soft-tissue analysis measurements, in my opinion, are all in the good to excellent range. The superior sulcus measurements are still good, as the overall form of the lip has been helped so much by the elimination of lip strain

as the incisors were retracted and the mandible grew horizontally. Arch length and treatment objectives dictated that this be treated as an extraction case. Facial photographs of this patient also confirm the wisdom of nonsurgical orthodontic treatment in her case (Fig. 18). The next case is shown in Figs. 19 and 20. In view of the very straight soft-tissue profile, the excellent mandibular form, the extreme retrusive inclination of the lingually erupting lower incisors (especially the lateral ones), and the very deep overbite, serial extraction was not indicated, even if permanent second premolars might have to be extracted later. This case was treated through the transitional dentition. Fig. 19,A shows that all of the soft-tissue analysis measurements contraindicated extractions. The lower incisor relationship to the A-pogonion line which, in my opinion, is the best guide that we have from hardtissue analysis regarding how far we might advance the lower incisors and still have a stable result and a healthy periodontium, also confirmed the decision to proceed on a nonextraction basis. The lower arch crowding was 5 mm. Note the 0” convexity figure, the 89” soft-tissue facial angle, the 8’ H angle, the good soft-tissue chin thickness and form, and a mandibular form that suggests horizontal growth. In Fig. 19, B, following nonextraction treatment, the soft-tissue analysis is even flatter, even though the lower central incisors were tipped labially 2 mm and the lateral incisor was tipped 7 mm. As anticipated, mandibular growth was almost entirely horizontal, resulting in a 91” soft-tissue facial angle (a 2” increase during the period of treatment) and a 6” H angle (2” decrease) associated with a -4 mm convexity figure. The lower lip has adequate curl, but overall the patient has an ultrastraight soft-tissue profile. Fig. 19, C shows this case 8 years later. The patient has experienced extreme forward rotational mandibular growth. The soft-tissue facial angle has continued to increase another 5” since retention to 96”. The continued vertical growth pattern of the lower teeth has been up and back, again resulting in a lower incisorto-pogonion ratio far on the minus side. The maxillary teeth have been carried more forward, so that the upper lip curl as measured to a line perpendicular to Frankfort plane is 3 mm, or 1 mm better than at retention. Again this is the type of extreme skeletal concavity in which measurements of the superior sulcus to the H line are meaningless because of the extreme cant on the H line. The convexity figure is - 8 mm, and the H angle is O”, again illustrating how the H angle varies with the skeletal convexity. In spite of his very prominent chin, this patient has maintained a pleasing appearance. The

Soft-tissue cephalometric

Volume 85 Number 4

Fig. 19. A Class I deep-overbite case extraction because of the soft-tissue

with a 5 mm lower analysis findings.

lower lip again seems to lack a little lip support, but the upper lip form and the overall expression are good. In Fig. 21 is shown the case analysis tracing of an l&year-old male patient who was sent to my office. He had undergone serial extraction at about the same stage of development as the previous case. The lower lip support has been lost because of the serial extraction, in my opinion. A more typical example of a Class II double protrusion problem and the resulting facial disharmonies produced by the malocclusion is illustrated in the tracing in Figs. 22 and 23. This patient is a white boy, 12 years 2 months of age, with good growth potential. Even though the gonial angle of the mandible is on the obtuse side, the skeletal convexity measurement of only 3 mm and the soft-tissue facial angle of 87” indicate that mandibular growth has been reasonably good and, if vertical relationships are managed well during the period of orthodontic treatment with an expected male adolescent growth spurt, the patient has an ideal potential as far as chin prominence is concerned. There is a severe disharmony in the position of the lip. This is

arch length

discrepancy.

It was treated

anulysis

291

without

quantitated in the analysis by measurements of the superior sulcus which measures 10 mm to the line perpendicular to the Frankfort plane and 18 mm to the H line. The lower lip was 6 mm outside the H line. The soft-tissue VT0 in Fig. 22, C dictated that the lower incisors be retracted 7 mm, even though an overjet of 9 mm was present and 3 mm of crowding was present in the lower arch. A further consideration was a carious exposure of the upper right first molar. The space and anchorage requirements plus the condition of the first molar dictated that the four first molars be extracted. The cephalometric tracing the day of retention in Fig. 22, B shows great improvement of lip positions. The superior sulcus depth measured to the line perpendicular to Frankfort has been reduced to 5 mm, and the measurement to the H line has been reduced to 7 mm. The lower lip measurement to the H line has been reduced to 2 mm. Chin prominence has improved, as shown by the soft-tissue facial plane of W, indicating excellent growth and control of vertical relationships during orthodontic treatment. Skeletal convexity has also been reduced to - 1 mm.

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Fig. 22. A severe Class II double protrusion. The VT0 showed that it was necessary to extract four first molars to achieve an adequate correction of the problem.

Fig.

20. For legend,

see

Fig. 21. Tracing of a case in which serial formed when they were contraindicated.

Fig.

19.

extractions

were

per-

Again there are some delayed upper lip thickness changes that often need more time to adapt. The original basic lip thickness measurement has increased from 14.5 mm to 17 mm, and at the vermilion border from 11 mm to 17 mm. There are several processes going on that explain this. First is the lip strain factor. While there was not a large amount of excess taper to the upper lip, there was 2.5 mm in the lip strain factor. The lips fail to adapt or retract as fast as teeth are retracted in about half of our cases. The other factor that may be influencing these measurements is a generalized thickening of the upper lip that occurs in about 40% of males with or without orthodontic treatment. Because further lip adaptive changes are expected and because favorable mandibular growth is anticipated, improvement toward more harmonious lip contours and relationships is expected. In Fig. 22, C is a copy of the VT0 for this patient. These are tremendous profile changes that we set out to accomplish in some of our orthodontic cases. One does not have to be a psychologist to know that something very good has happened to this young man’s self-image (Fig. 23). Truly, a liability has been removed, so that his own natural talents and personality have developed normally.

Volume 85 Number 4

Soft-tissue cephalometric

Fig.

23. For legend,

see

Fig. 22.

SUMMARY

To summarize, the soft-tissue profile can vary in many ways and still be in balance and harmony. There is a wide range of acceptability regarding soft-tissue chin position in the profile. Both the lips and the chin should line up near the H line, but we need to look at the upper lip from a different perspective or in its relation to a line perpendicular to the Frankfort plane and tangent to the vermilion border to be certain that we are planning the best possible lip support for the case at hand. The H angle, allowing a few degrees for soft-tissue thickness variability, must increase as the basic skeletal convexity increases, and as the convexity increases, the lower incisors will need to be left farther

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forward than in a straight or concave skeletal profile. A thick integumental covering in the chin area can also effectively align the lower facial profile where lower incisors are farther forward than we are accustomed to seeing them. This principle can also be applied by surgically moving the bony chin forward until the three key soft-tissue points line up. Because there are wide variations in skeletal convexity, standardizing the position of the lower incisor to its apical base support as measured in the Frankfort mandibular incisor angle fails to recognize that upper incisors can be retracted too far, leaving a “streamlined” upper lip which is not esthetically pleasing. Locating the lower incisor in relation to the expected point A to pogonion line is somewhat better but still fails to recognize the wide range of variability in the thickness of the lips and soft-tissue chin. We must also guard against “dishing” those cases having good facial balance with quite normal skeletal convexity and only 5 mm or 6 mm of lower arch length discrepancy. Finally, it is completely practical as a treatmentplanning procedure to approach the proposed orthodontic changes from a soft-tissue analysis perspective, making changes only to the point where the best possible soft-tissue profile is established, and then compute the tooth movement necessary to develop ideal profile relationships. The visualized treatment objective, or VTO, is the vehicle that I use to accomplish this. REFERENCES

1. Holdaway RA: A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part I. AM J ORTHOD 84: l-28, 1983. 2. Ricketts RM: Cephalometric synthesis. AM J ORTHOD 46: 647673, 1960. 3. Jacobsen A, Sadowsky PL: A visualized treatment objective. J Clin Orthod 14: 554-57 1, 1980. Reprint requests to: Dr. Reed A. Holdaway 1275 N. University Provo, UT 84601

ERRATUM In “A Soft-Tissue Cephalometric Analysis and Its Use in Orthodontic Treatment Planning. Part I ” by Holdaway, which appeared on pages 1 to 28 of the July, 1983, issue of the JOURNAL, the top and bottom portions of two illustrations were inadvertently transposed. In Fig. 9 the bottom tracing should have been part A and the top tracing part B . In Fig. 29 the bottom figure is the malocclusion tracing and the top one is the retention tracing.