A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part IReed A. HoldawayProvo, Utah
This article presents a soft-tissue analysis which demonstrates the inadequacy of using a hard-tissue analysis alone for treatment planning. The material and methods used to develop this technique came from years of observation and description of patients from the private practice of the author. The findings indicate that, in general, for adolescents the normal or usual thickness of the soft tissue at point A is 14 to 16 mm. As point A is altered by tooth movement, headgear, etc., the soft tissue will follow this point and remain the same thickness. When there is taper in the maxillary lip immediately anterior to the incisor, as in protrusive dentures, the tissue will thicken as the incisors are moved lingually until the tissue approaches the thickness at point A (within 1 mm. of the thickness at point A). When the lip taper has been eliminated, further lingual movement of the incisor will now cause the lip to follow the incisors in a one-to-one ratio. These concepts are predictable in adolescents when the lip thickness at point A is within the normal range. Some exceptions are as follows: Even if there is lip taper, if the tissue thickness at point A is very thin (for example, 9 to 10 mm.), the lip may follow the incisor immediately and still retain the taper. If the tissue at point A is very thick (for example, 18 to 20 mm.), the lip may not follow incisor movement at all. Adult tissue reaction is similar to the first exception. Even though there may be lip taper, the lips will usually follow the teeth immediately. Cases are presented to demonstrate these concepts and to illustrate a normal or acceptable range of variation for facial harmony related to variations in skeletal convexity.
The soft-tissue profile plays an important part in our orthodontic considerations. Usually, as we correct malocclusions, we bring about changes in appearance that are pleasing to all concerned. However, most orthodontists who have practiced for even a few years have had the unpleasant experience of finding that some patients' faces looked better before the orthodontic corrections were made. We should determine beforehand that the proposed orthodontic treatment will not result in adverse facial change. This analysis is an attempt to express quantitatively those soft-tissue relationships which are pleasing and harmonious as well as those which are not, to differentiate one from the other, and to explain how this information is used in orthodontic treatment planning.
Steiner has stated that there are hundreds of measurements that one can use in the tracing of a head film. He cautioned. however, that we must not let the number of things that we measure become so complicated and unwieldy that it ceases to be practical. This analysis was developed with simplicity and directness in mind. Because of the fundamental information that can be recorded in a hard-tissue cephalometric analysis, there are few of us who do not use a cephalometric approach today. There is additional information which can be taken from a study of the structures in the integumental covering of those hard tissues that we should recognize as being even more meaningful. This is a soft-tissue approach to treatment planning.
In the analysis of my patients during the time that I was an instructor in the Tweed course, there were very few cases in which the FMIA goal had not been satisfied. There was still that 20 to 25
percent of the cases in which something was lacking as far as harmony of facial lines was concerned when only the Tweed diagnostic triangle was used as a treatment-planning tool. This limitation was also recognized by Tweed himself. Hindsight and follow-up review disclosed that these cases either lacked appropriate lip support or had excessive vertical height in the denture area.
The study of other treatment-planning procedures which had come into vogue during the l950s and 1960s suggested a strong tendency for the lower incisors to be located very near the A-pogonion line in the good faces. Downs and Ricketts1 have pointed this out many times, but the A-pogonion line also had its exceptions as a treatment-planning tool.
As orthodontists, we were looking for a better hard-tissue measurement that would result in 100 percent of the patients meeting all of the requirements set forth by Dr. Tweed2 as objectives in orthodontic treatment. These objectives were as follows: (1) The best balance and harmony of facial lines that is possible, (2) stability of the denture after treatment, (3) healthy oral tissues, and (4) an efficient chewing mechanism. Such a single hard-tissue measurement does not exist. There is, however, considerable help to be gained from a soft-tissue analysis.
Facial balance as related to orthodontics has been a subject of special interest to me for a long time. Excellence of occlusion, however, is still paramount.
Returning to my theme of physical attractiveness, in a newspaper article approved by the American Medical Association on Aug. 28, 1979, the fact that so much plastic surgery is being performed of late was explained as follows: ''Physical appearance is our calling card. An attractive and pleasant appearance opens doors. It is not merely vanity that prompts tens of thousands of Americans each year to turn to cosmetic surgery to seek improvement of physical appearance. Plastic surgical operations do not magically give new talents or personalities to people. Rather, they take away a liability so that the person's own natural talents and personality can develop normally."
Certainly the same explanation is valid for our efforts in the correction of those facial liabilities associated with malocclusion. Lee Graber3 states: ''A physical attractiveness stereotype per se really permeates our entire developmental process and, to some extent, our entire society.''
Citing one study of teacher expectations from children in a schoolroom setting, Graber reports: "It was determined that teachers often, on the basis of just how the child looks, say that they can tell how intelligent the child is, how far the child will go in school, the popularity of the child, the parental interest in the child's education, and the future success of the child in life."
Graber further points out: "Attractiveness correlates with high teacher expectations, even though there is no correlation between I.Q. or native intelligence and attractiveness. There is also a positive attractiveness bias not only of teacher to child but also how the child reacts with his peer group."
Graber referred to studies which showed that even parents react differently to their children on the basis of their looks. He further states: "The way they look influences the parents' predictions of a
child's personal and social success. It does not influence, however, the parents' opinion of how well the child will do academically."
Physical attractiveness, especially of children, is often influenced to a considerable extent by the orthodontic treatment that we, as orthodontists, give them. Understanding how important is the psychological development of young persons and how their social development is related to attractiveness and favorable self-image, it is imperative that we take very seriously the matter of giving our patients the best possible balance and harmony of facial lines. We must also be concerned about doing this early enough in the child's development that no permanent poor self-image concepts are acquired before we customarily begin our orthodontic corrections.
Better treatment goals can be set if we quantitate the soft-tissue features which contribute to or detract from that "physical attractiveness stereotype'' which has been ingrained into our culture. The need to improve treatment goals for our patients is the primary reason for this soft-tissue analysis.
METHODS
The eleven measurements that are used in the analysis are illustrated in Figs. 1A and 1B.
Soft-tissue analysis
The tracings in Fig. 1B show the lines and measurements that are meaningful or helpful in an evaluation of the balance and harmony of a given face.4 A description of the eleven measurements follows:
Soft-tissue facial angle (Fig. 2). This is an angular measurement of a line drawn from soft-tissue nasion, where the sella-nasion line crosses the soft-tissue profile, to the soft-tissue chin at a point overlying the hard-tissue suprapogonion of Ricketts measured to the Frankfort horizontal plane. This chin point is chosen because of the bony stability here during growth and because in cases in which there is hypermentalis activity resulting in an uneven distribution of the integumental covering of the bony chin it is a more realistic point at which to measure the chin prominence. It is a better measurement of chin prominence in a face than the hard-tissue facial angle because of the wide range of variations that we find in the thickness of the soft-tissue chin. A measurement of 91 degrees is ideal, with an acceptable range of ±7 degrees.
In discussing any given face, we need to be able to state in a specific way just how prominent (prognathic) or how receding (retrognathic) the lower face or soft-tissue chin area really is as illustrated by these extreme types (Fig. 3). Of all the bones that make up the facial complex, the one with the greatest variation in size and form is the mandible. Mandibles may be large or small in the body, the ramus portions, the condylar processes, or all of these. The gonial angle also exhibits extreme variation, as Ricketts and others have pointed out. When we speak of the variation in people's faces, we are talking more about the type of lower face form than anything else, except perhaps the nose. The wide variation in nose form is due more to variations in soft tissues and
cartilage than to variations in just the nasal bones. These variables in mandibular form and soft-tissue chin thickness may produce an ideal prominence of the chin in a variety of ways.
We do encounter cases in which surgical help is needed to alter the basic framework of the face.
While, ideally, I prefer a soft-tissue facial angle of 90 to 92 degrees, I also recognize a rather wide range of very acceptable variation, possibly as high as ±7 degrees, at least for some cases (Figs. 4 and 5).
Careful planning of treatment for each case, with the final result visualized as part of the treatment planning, will facilitate its achievement. We also must not be afraid to tackle challenging problems as long as there is a potential for successful orthodontic treatment alone. Surgical help is needed in only a small percentage of our cases.
The superimposed profile tracings in Fig. 5, oriented to the Frankfort plane, represent a considerable range of variation in soft-tissue chin position, all of which is amenable to orthodontic correction alone unless complicated by vertical dysplasia problems.
The SNB angle so often used to express mandibular prominence is less effective in quantitating this facial feature, not only because of both bony and soft-tissue chin variables but also because both sella and nasion vary considerably as to high or low placement. The soft-tissue facial angle offers a better means of quantitating the profile chin position.
Nose prominence. Next in importance to variations in chin position are variations in noses. Nose prominence can be measured by means of a line perpendicular to Frankfort horizontal and running tangent to the vermilion border of the upper lip. This measures the nose from its tip in front of the line and the depth of the incurvation of the upper lip to the line (Fig. 6). Arbitrarily, those noses under 14 mm. are considered small, while those above 24 mm. are in the large or prominent range. Nasal form should be judged on an individual basis.
Superior sulcus depth measured to a perpendicular to Frankfort and tangent to the vermilion border to the upper lip (Figs. 1B and 7). Next let us consider the upper lip form or curl. This is the superior sulcus depth measured to the same perpendicular to Frankfort. A range of 1 to 4 mm. is acceptable in certain types of faces, with 3 mm. being ideal. This measurement is especially useful in cases found to be on either extreme of facial convexity where a measurement to the H line (harmony line) is misleading because of the change in the cant of this line in highly convex or concave faces. This is a simple way to quantitate the actual curl of the upper lip. Observing this measurement and setting treatment goals accordingly should reduce the number of orthodontically treated patients who develop an unpleasant expression in this area as a result of too much retraction of anterior teeth. The most frequent comment heard in criticism of orthodontics comes from parents of prospective patients who do not like the changes in upper lip position that they have observed in some orthodontically treated patients. Orthodontic treatment goals based solely on hard-tissue analyses may require excessive retraction of the upper incisors in many cases. During orthodontic
treatment or surgical orthodontic procedures, we should strive never to allow this measurement to become less than 1.5 mm. Faces with average lip thickness where there is a 3 mm. measurement are preferred. However, in cases of high skeletal convexity, especially associated with mandibles that have obtuse gonial angles and long lower face dimension, or in cases of very thin lips, it may be necessary to settle for a 1 mm. measurement. With less face height, more prominent chins, and longer or thicker upper lips, a measurement of up to 4 mm. may not be excessive. The upper lip form is considered to be of such importance in the study of facial lines that its perspective in relation to both lines (the line perpendicular to Frankfort and the H line) is needed for the decision as to where the denture should be oriented to provide the best possible lip support.
The nasolabial angle has been used as a measurement to help us avoid the creation of disharmony in this critical area. However, it fails to tell us whether the angle is excessive because the lip slants back, because the nose turns up, or both. Thus, it fails to adequately describe contour in the subnasal profile. In my opinion, a perpendicular to Frankfort is better for our use than the nasolabial angle or measurement of the area to the H line, the E line, the Z line, or the S line of Steiner.
Measurement (Figs. 1B and 8) of soft-tissue subnasale to H line. Here the ideal is 5 mm., with a range of 3 to 7 mm. When the skeletal convexity of a case will be from – 3 to +5 mm. at retention, the lips can usually be aligned nicely along the H line when the superior sulcus measurement is at or near 5 mm. With short and/or thin lips, 3 mm. will be adequate (Fig. 9, A). In longer and/or thicker lips, 7 mm. may be in excellent balance (Fig. 9, B).
If this measurement were 8 or 9 mm. in the latter situation, with no evidence of lip strain or lack of harmony of facial lines, extraction of four premolars just to reach this goal would not be indicated. The measurement is a very useful guide, however, and is used routinely to visualize the best lip position for a case when a Visualized Treatment Objective (VTO) is constructed. The H line does follow the general line of the lower face. Our sense of proportion is offended if this is out of proportion to the general convexity and type of face or if the lower lip fails to fall near it. Both lips, however, need their own adequate contour, and this is especially true of the upper lip.
In cases found to be on either extreme of the skeletal convexity spectrum, the ideal measurements to the H line lose their significance because of the change in the cant of the H line (Fig. 10). It is obvious that the measurements of upper lip curl are more meaningful in these extreme patterns when measured to the line perpendicular to Frankfort. Only a small percentage of well-treated orthodontic cases are outside the best convexity range of – 3 to +4 mm., so this measurement is used in most of our cases for treatment-planning purposes as we do a VTO.
Skeletal profile convexity. This is a measurement from point A to the hard-tissue line Na-Pog or facial plane (Fig. 11). This is not really a soft-tissue measurement, but convexity is directly interrelated to harmonious lip positions and, therefore, has a bearing on the dental relationships needed to produce harmony of the features of the human face. This will be illustrated later in the discussion of the H angle, which must vary with skeletal convexity if pleasing facial form is to be achieved.
Basic upper lip thickness (Fig. 12). This is near the base of the alveolar process, measured about 3 mm. below point A. It is at a level just below where the nasal structures influence the drape of the upper lip. This measurement is useful, when compared to the lip thickness overlying the incisor crowns at the level of the vermilion border, in determining the amount of lip strain or incompetency present as the patient closes his or her lips over protrusive teeth.
Upper lip strain measurement. The usual thickness at the vermilion border level is 13 to 14 mm. (Fig. 12, B). Excessive taper is indicative of the thinning of the upper lip as it is stretched over protrusive teeth; also, excessive vertical height may produce more than 1 mm. of taper due to lip stretching. When the lip thickness at the vermilion border is larger than the basic thickness measurement, this usually identifies a lack of vertical growth of the lower face with a deep overbite and resulting lip redundancy. Lip strain must be considered when one is doing a VTO if such an objective is to be realistic.
H angle. This is an angular measurement of the H line to the soft-tissue Na-Po line or soft-tissue facial plane. Ten degrees is ideal when the convexity measurement is 0 mm. (Table I). However, measurements of 7 to 15 degrees are all in the best range as dictated by the convexity present (Fig. 13, B). Ideally, as the skeletal convexity increases, the H angle must also increase if a harmonious drape of soft tissues is to be realized in varying degrees of profile convexity. These observations have been based on the patients in my practice, who are of predominantly northern European ancestry.
Observations indicate that as the skeletal convexity increases so also does the convexity of the soft-tissue profile if the entire facial complex is to be one of balance and harmony with its type. This observation was made when the Steiner analysis was used, and so convexity was expressed by an ANB angle and the profile vertical line used to form the H angle was the NB line. Professor Hasund at the University of Bergen in Norway has confirmed the statistical significance of the original variable H angle concept. His article states: "The result confirms Holdaway's statement that the ANB angle is the main guiding variable in an evaluation of the magnitude of the H angle."
Clinically, the revised H angle appears far superior to the original H angle. This can be explained by the variability of the chin area, which is not considered by the ANB angle. This angle measures the prominence of the upper lip in relation to the over-all soft-tissue profile. When the profile convexity is outside that indicated as the best range in the chart (Table I), one may on occasion plan the denture orientation a little differently from the chart to attempt to mask skeletal problems and soft-tissue distribution problems. This must not be done, however, at the expense of leaving the lips without proper dentoalveolar support, in which case the upper lip would be left without the bare minimum of 1 mm. of curl or that the lower lip would be left located too far behind the H line.
This concept of a variable ideal soft-tissue profile related to basic skeletal convexity is illustrated by cephalometric tracings and photographs of three cases (Figs. 14, 15, and 16) which exhibit a wide range of convexity. Note how the H angle increases in each of these cases as we go from
The patient shown in Fig. 14 demonstrates why we need to consider a variable H angle based on profile convexity. This is really a double protrusion. When teeth are extracted and the denture is set back so that the superior sulcus depth is reduced to ideal form, the lower lip falls on the H line and harmonious relationships result, even though the convexity measurement of point A to the facial plane has now become – 4 mm. It should also be noted that this patient has a prominent chin with a soft-tissue facial angle of 93 degrees and still there is a very feminine, refined appearance when the lip support is correct for her skeletal pattern.
The case shown in Fig. 15 has the potential for an excellent change to ideal soft-tissue analysis measurements. The basic soft-tissue chin position is excellent, and the 3 mm. of convexity is not excessive. The 16-degree H angle is high but ideal for nonextraction treatment unless dictated otherwise by crowded arches. Arch length was manageable in this case. Note the nice improvement at completion of the Class II correction, where the H angle is 10 degrees with a O convexity. Treatment has resulted in very nice lip support as seen both in photographs and in the retention tracing.
Finally, let us consider a highly convex skeletal pattern with a lack of chin prominence as shown in the 83-degree soft-tissue facial angle (Fig. 16). There is 12 mm. of convexity and a 32-degree H angle, which is still 10 degrees too high, even for this amount of convexity. Our treatment domain is from 84 to 98 degrees, so that 83 degrees begins to look like an almost impossible challenge to orthodontic treatment alone. Extractions will be indicated in most cases that have this degree of severity. At retention the convexity measurement is 8 mm. There is, however, adequate curl or form left in the upper lip, and the lower lip is nicely positioned along the H line with a pleasing and balancing form to the superior lip sulcus. If we add the basic 10 degrees to the convexity figure of 8, we have an 18-degree H angle as a goal. The actual H angle is 19 degrees, or 13 degrees less than at the beginning of orthodontic treatment. In my opinion, the face has been brought into improved balance and harmony for its highly convex type without the aid of surgery. The H angle will vary + or – 2 degrees from the chart because of variations in distribution of the soft tissues in the profile.
Changes in the H angle in longitudinal studies also reflect the direction of growth, especially of the mandible. This measures change during treatment or observation periods in the same patient and quantitates differences between one patient and another.
The H angle, when considered with the basic skeletal convexity of a face and sulcus depth measurements, can be used as a guide in planning the anteroposterior position of the denture to give proper lip support and a natural unstrained drape of the soft tissues covering the denture area of the face.
Some cases present bizarre variations in the thickness of the soft tissues (Fig. 17). We have little control over this, but these variations need to be recognized in determining the best possible orientation for teeth.
Lower lip to H line (Fig. 18). The ideal position of the lower lip to the H line is 0 to 0.5 mm. anterior, but individual variations from 1 mm. behind to 2 mm. in front of the H line are considered to be in a good range. When the lower lip is situated behind the H line, the measurement is considered to be a minus figure. A lower lip measurement of much more than – 1 mm. when other profile measurements are only reasonably good is indicative of lower incisors that are positioned too far lingually.
This may have resulted from orthodontic treatment (Fig. 19), serial extraction where this procedure was contraindicated, premature exfoliation of deciduous canines, or even the early loss of first permanent molars. Often these arches condense with lingual collapse of the lower incisors and proper lip support is lost. They are orthodontically and/or surgically repositioned anteriorly to restore the lost lip support.
When the lower lip rolls out more than 2 mm. beyond the H line, the denture is usually protrusive, or at least the upper incisors are protrusive, and an excessive overjet and/or overbite is present. This was illustrated by our main illustration case in the before-treatment tracings (Fig. 1B).
We also observe this relationship of the lower lip to the H line in cases in which there is an abnormal distribution in the amount of lip material in the two lips. A common example of this is found in many of our cleft lip cases in which surgical procedures have been performed. Many of these are deficient in upper lip thickness; hence, the more normal lower lip falls outside the H line (Fig. 20, A). If one attempts to plump out the upper lip in these cases by advancing the upper incisors, the lip stays at about the same position but is pressed thinner still. There are other patients besides those with clefts who lack material in the upper lip, not only in length but in thickness as well.
Lack of chin (either bony, soft-tissue, or both) can also bring the lower end of the H line too far back so that the lower lip is positioned too far in front of the H line (Fig. 21). Nearly all such cases have a low soft-tissue facial angle; sliding genioplasty surgical procedures can be very beneficial in some of these cases by advancing the lower end of the H line so that the chin is better positioned in the over-all profile as well as in relation to the lips along the H line. Chin augmentation using a number of different prosthetic materials has proved to be disappointing because some tend to cause resorption of the already deficient bony chin.
Inferior sulcus to the H line. The contour in the inferior sulcus area should fall into harmonious lines with the superior sulcus form. This is measured at the point of greatest incurvation between the vermilion border of the lower lip and the soft-tissue chin and is measured to the H line (Fig. 22). It is an indicator of how well we manage axial inclinations of the lower anterior teeth. Leveling procedures on round arch wires may cause a lingual tipping of the lower incisor roots with point B following and thus exaggerate an already excessive labiomental furrow and a prominent chin.
We may err in the other direction as lower incisors are depressed and retracted with labial root torque, resulting in a lower lip that has too little form in the inferior sulcus area, as is the case in the
adult patient shown in Fig. 23. Facially, this represents a tremendous improvement in a difficult adult double protrusion. If the lower incisor roots had been moved lingually about 3 mm., the result might have been a lip-to-chin area with better balancing contour to that of the superior sulcus (Fig. 23, A and B). On the other hand, doing so would have used up more anchorage and the double protrusion might not have been corrected as well as it was.
Soft-tissue chin thickness (10 to 12 mm. average). This is recorded as a horizontal measurement and is the distance between the two vertical lines representing the hard-tissue and soft-tissue facial planes at the level of Ricketts' suprapogonion. Usually, these lines diverge only slightly from the area of nasion down to the chin. Large variations, such as 19 mm. of thickness (Fig. 17), need to be recognized, and in such cases it is essential to leave the lower incisors and hence the upper incisors in a more anterior position and to avoid the tendency to take away needed lip support (Fig. 24).
DISCUSSION
We will now consider the application of the eleven soft-tissue analysis measurements in the evaluation of harmony or disharmony of facial profiles. The next series of tracings show the measurements of certain features and relationships which identify some persons in our culture as handsome or beautiful as well as those which make for an unpleasant expression or facial appearance. Even in a sample of beauty queens, not everyone has an ideal occlusion.
Fig. 25, A shows a tracing of a Miss America. The 91-degree soft-tissue facial angle denotes a good soft-tissue chin position, and the – 3 mm. skeletal convexity indicates a slightly concave skeletal pattern. Thus, for the lip form to be pleasing, we would expect to find an H angle of 7 degrees, which this person has. A total size of 21 mm. is average for an adult nose. As we look at the profile lip outlines, we see that they drape with adequate curl and pleasing form. Confirming this, we find the superior sulcus measuring 5 mm. to the H line and 4 mm. to a perpendicular to Frankfort plane. This young woman seems to have a slight excess of lower lip material, with the lower lip just outside the H line, but this is still in a nearly perfect position near the center of the range from 1 mm. behind the H line to 2 mm. in front of it. Upper lip thickness is less than average and has 2 mm. of taper, but this is a normal variation rather than an indication that lip strain is present. The inferior sulcus measures 5.5 mm. with a form that harmonizes nicely with that of the superior sulcus, and the 12 mm. soft-tissue chin thickness is just average tissue thickness in this area. Over all, these are excellent figures, as one would expect of a Miss America.
In Fig. 25, B, a runner-up Miss Universe presents a less prominent chin that has a soft-tissue facial angle of 87 degrees. With this chin position, it is not surprising to find 1 mm. of skeletal convexity. Also, the upper lip is a couple of millimeters thicker than that of the Miss America. We would expect to find an H angle of 12 degrees instead of the 11 degrees that the chart indicates for a face with a 1 mm. convexity. Again, there is a good adult nose of 22 mm. Note how the H line falls exactly on the lower lip and the superior sulcus measures 5 mm. to the H line and 3 mm. to the perpendicular to Frankfort plane, which is ideal. This young woman has an inferior sulcus depth of 4.5 mm. and an average soft-tissue chin thickness of 11 mm., which are also ideal.
Let us now discuss the Class II Miss Virginia whose tracing is shown in Fig. 25, C. She has the same chin prominence as the Miss Universe runner-up. With the Class II malocclusion, it is not surprising that she has 3.5 mm. of skeletal convexity and, with this, a 14-degree H angle. Once again, that very important area of the superior sulcus measures 5 mm. to the H line and 3 mm. to the perpendicular to Frankfort. The lower lip falls on the H line, there is beautiful form to the lips, and the inferior sulcus is not excessive even with this amount of overbite and overjet. The soft-tissue chin measurement is 13 mm., which was really needed in this Class II pattern. It would be very difficult to correct the malocclusion without losing something in the way of facial beuty.
Cases treated to only hard-tissue goals
Now let us compare these cases to a few that were treated to only hard-tissue goals. The first of these is an 18-year-old female patient who has a Class II, Division 1 malocclusion with 6 mm. of lower arch crowding (Fig. 26). From the soft-tissue analysis and from the pretreatment photographs, it is evident that she was very attractive. This profile reminds me of the Class II Miss Virginia whose tracing was shown earlier. There is a good chin position and a good, straight profile with a 0 convexity measurement and a 12-degree H angle, only 2 degrees above the ideal for 0 convexity. The superior sulcus measures 5 mm. to the H line and 3 mm. to the perpendicular line, both being ideal in my opinion. The inferior sulcus depth of 7 mm. is a little large because of the prominent bony chin, but certainly still in a good range as far as over-all form is concerned. Note that the lower incisor falls on the facial plane and the APO line, but there is still a 5 mm. overjet to reckon with plus the lower arch crowding. The plaster models gave no clues. If we look at the inclination of the lower incisor to Frankfort, we see an FMIA of 58 degrees. Thus, neither the Tweed approach nor the A-Po line gave any warning of possible disastrous effects of retracting the upper anterior teeth. Certainly the A-Po line approach would have left better lip support than the Tweed triangle approach. This case was treated to Dr. Tweed's measurements. It, of course, falls into that 20 to 25 percent of the cases that just do not work out when that approach is used.
The after-treatment tracing shows poor balance and lack of harmony of facial lines. What was once proper lip support for the pattern is now an unpleasant double retrusion. There was not any growth. The chin prominence is still 89 degrees but the patient's appearance after treatment calls attention to both chin and nose because the nice lip support was taken away. There is a O measurement to the perpendicular line and only 1 mm. to the H line, but of course the worst disharmony appears on the lower lip, which is 3.5 mm. behind the H line.
The H angle should not have been reduced more than 2 degrees because of the excellent lip form measurements. By following the hard-tissue-measurement treatment planning that was used at that time, an 8-degree change was made in the H angle. There was 3 mm. excessive upper lip taper, which probably had become permanent in form at this age. Normally we anticipate that the upper incisors can be retracted 3 mm. without altering the upper lip position, as we often see in young patients and which is looked upon as a stretching of the upper lip over protrusive teeth, thus producing a thinning of the lip. This lip-strain factor which, if eliminated before basic lip form has
been permanently altered, is a definite plus in this type of case, especially when younger patients are being treated, because the upper incisors can be retracted until the abnormal tension or lip strain is eliminated without reducing the H angle. Return to a normal 1 mm. taper seldom occurs in older patients such as this one. Starting with a soft-tissue analysis of a face like this, one would certainly treat the case differently or not at all. The terms dished and streamlined have been used for years to describe orthodontic overtreatment. To me, this case was dished, while the next case that I want to talk about was streamlined.
In this case (Fig. 27) we are considering a 13½- year-old Caucasian girl with a Class II, Division 1 malocclusion. In contrast to the previous case, before treatment this girl definitely lacked facial balance and harmony in relation to to her malocclusion. This was traded for a changed profile, but it is questionable whether it was an improvement. The 88-degree soft-tissue chin position was not bad, even though the patient had very little bony chin. She had a convex skeletal pattern with a convexity measurement of 7 mm., but we have already looked at a case with a much more severe convexity than this that treated out nicely. Other than the excessive taper of 5 mm. in the upper lip, denoting a great deal of lip strain on lip closure, there are no unfavorable soft-tissue thickness measurements anywhere in the profile. The H angle of 25 degrees is 8 degrees high for a 7 mm. convexity case. Some hard-tissue measurements that may be of interest are an FMIA of 50 degrees and a lower incisor that is 4 mm. anterior to the A-Po line. At retention, the FMIA has been increased to 67 degrees, and the lower incisor is just a line in front of the A-Po line. By both of these hard-tissue approaches, this patient should rate high on a scale of physical attractiveness. Of course, she does not because little attention was paid to the critical area of the superior sulcus, which started out at only 2 mm. She lacks form or curl of the lips, especially the upper lip. The important measurement here is the superior sulcus depth measured to the perpendicular line from Frankfort. Here we have a – 2 mm. measurement after treatment, and the very least amount of lip support that we ought to leave in the upper lip, even in difficult cases, is + 1 mm. In a highly convex pattern we must discount the superior sulcus measurement to the H line because of the angle of the H line that is dictated by the convexity. In planning the proper denture orientation for such a case via the VTO approach, careful consideration must be given to the change in form of the upper lip when lip strain is eliminated plus the need to establish acceptable measurements from both perspectives, that is, to the perpendicular line from Frankfort and the H line. To me, this face is streamlined. It could have been worse if the soft-tissue facial angle had been in the low 80's instead of 88 degrees. It also tends to appear worse when there is excessive lower face height. This case was chosen in order to reduce the number of contributing factors to a minimum (Fig. 28). Based on the soft-tissue profile findings, let me present a VTO plan of treatment such as I would use today in planning treatment of this case. This would let the patient have a much higher physical attractiveness rating than she now has.
Instead of planning to have the upper lip come back 6.5 mm., as occurred in the actual treatment of the case, I would plan on a position only 2 mm. back. This would bring the superior sulcus measurement to the H line down to 7 mm., or in the good range according to type. What about the 2 mm. measurement to the perpendicular line? Would all this precious but small amount of lip curl be lost? No. With 4 mm. excessive taper of the upper lip representing lip strain, lip form would actually
be improved. The measurement would not increase, but the form would get better to this point. The lower lip might still be outside the H line as shown, but this is really not nearly so critical as the upper lip form. How does this translate in terms of tooth movement? Instead of moving the lower incisors back 5 mm., they would be left where they were in the malocclusion. The FMIA would still be 50 degrees instead of 67 degrees, and because point A would be moved back about 2 mm., the lower incisor would be at about 5 mm. anterior to the A-Po line. Lower premolars would not be extracted.
Instead of retracting the maxillary incisors 11 mm., a retraction of 6 mm. would be enough. In a 13½-year-old girl with very little growth occurring, complete distal movement of the maxillary arch would probably not be possible, so the upper first premolars would be extracted and a Class II molar relation would be allowed to remain. One could elect to have the upper second molars extracted, but that requires holding the lower second molars down until the upper third molars have erupted, and sometimes that can take a long time.
This patient would get along very well with her soft-tissue chin left at 88 degrees to Frankfort. This would leave an H angle, as shown in the VTO, of 20 degrees and a convexity measurement of 5 mm. The chart tells us that it ought to be just 15 degrees. If we construct a new H line tangent to both lips, we then see that if the chin were moved forward by a sliding genioplasty oral surgery procedure, the soft-tissue facial angle would increase about 2 degrees to 90 degrees and the H angle would decrease to 15 degrees. Remember that it is more important to treat to ideal upper lip form than to achieve the exact H angle outlined on the chart. However, both concepts are useful in planning for the best in facial esthetics for our patients. The assumption that treatment planning using hard-tissue analysis will always prevent these pitfalls is without support.
Variations in response
Before we get into treatment planning from a soft-tissue approach, we need to discuss the varying lip responses to retraction of the anterior teeth. Responses vary with type of lip structure and also with the patient's age and sex.
One must first understand this variable behavior of these integumental tissues before attempting a VTO to find the best position for the lower incisors from an anteroposterior perspective based on the soft-tissue profile. The basic steps of the procedure were published without some of this important soft-tissue response information.5 Application of the VTO in a rote manner without knowledge of these variables may lead to disappointment.
Contrary to most of the literature on the subject, over the long term (considered a minimum of 5 years after retention and after the lip strain is eliminated), the upper lip will follow the tooth movement with two exceptions. The first exception is found in those patients who have or who are developing very thick lips. When the thickness of the upper lip at the vermilion border exceeds 18 mm., the upper lip usually changes very little if at all when the upper incisors are retracted. When the lip measures 16 or 17 mm., it will be very slow in acquiring its final adaptation to or drape over
the teeth. If the thickness of the upper lip is in the common range of 13 to 15 mm., it usually follows the tooth movement quite well, but some of this group still show a thicker lip measurement at the vermilion border at retention than at the beginning of treatment. For this group, in 6 to 24 months the lip has nearly always caught up with tooth movement and has returned to its normal measurement. When the upper lip thickness at the vermilion border is 12 mm. and under and it is not due to stretching of the lip over protrusive teeth (lip -strain factor), the lip usually moves back just as fast as the teeth are moved. One need be concerned only about those in the thick-measurement group and older patients with excessive taper of the upper lip. In the others the tooth movement is planned for the final lip position visualized as being the most desirable for that patient. Patients will not all be at that point in the adaptation process at the time of retention, but they will get there. This is much better than overtreating the dentition and showing a balanced lip position at retention and then watching it deteriorate after treatment as the lips, especially the upper lip, finally catch up.
This is illustrated by Figs. 29 and 30. Here we may draw the conclusion that it is the final lip balance that must be of concern, rather than the profile position of the lips at the time of retention which may not be reflecting the actual lip support from the dentition at that point in time.
We see lips that cannot close without conscious strained effort in a great many of our protrusive cases. If there is lip strain in the malocclusion, this must be taken into consideration in treatment planning with the VTO. When lip strain is present, the upper lip must stretch over protrusive teeth on closure and, in so doing, it becomes thinner as it is stretched. If there is also excessive vertical height in the lower face, this compounds the problem. In cases such as those shown in Figs. 31 and 32 we find this lip strain showing up as an excessive amount of taper between the two thickness measurements of the upper lip.
In severe Class II cases it may be necessary to record a centric relation check bite of the teeth in order to keep the mandible from moving forward while the head film is being taken, thus removing part of the strain to keep the lips closed as well as negating other cephalometric measurements. The 11 mm. measurement tells me that there is 4 mm. excessive taper due to stretching of the lip. In other words, the teeth can be retracted 4 mm. before the upper lip will even begin to follow. At that point we would have a 15 mm. lip thickness at the vermilion border but the patient would be able to close the lips without conscious effort. This does not mean that by retracting the anterior teeth 4 mm. we caused the lip to thicken. It can simply close in its natural form, which would be 15 mm. or very close to that. There will be some minor variation from this, but it is a good and workable formula to use in treatment planning. After the lip strain has been eliminated, the soft-tissue analysis measurements would still be the same, except for the lip-strain measurement and possibly some help on the lower lip which originally was 4 mm. anterior to the H line.
At retention, as seen in Fig. 31, note that the lip-thickness measurements have increased tremendously, especially at the vermilion border level where it is 19 mm., or 8 mm. greater than in the original tracing. This, of course, shows that the lips have not kept pace with tooth movement. One might look at both sulcus measurements and decide that, while the lips line up nicely, they are still on the full side.
When we look at a tracing of the same patient 7 years later, with a continuation of the lip-adaptation changes and growth (Fig. 32), we see that the upper lip has the same basic lip thickness measurement of 16 mm. that it started with, and there is just an ideal 1 mm. taper to the vermilion border. measurement of 15 mm. All of the measurements are excellent, but it took several years for these final relationships to be achieved. We started out with 4 mm. of convexity and a 23-degree H angle, which is 9 degrees too high for the convexity. At retention the convexity had been reduced to 1 mm. and the H angle to 15 degrees. After final lip adaptive changes and growth, increasing the soft-tissue facial angle from 88 degrees to 90 degrees, we now have a 0 convexity and an ideal 10-degree H angle. In the photographs we see exactly the same thing. The trouble with photographs is that they do not lend themselves to precise quantitative measurements, as do cephalometric head film tracings.
There are, however, some cases of excessive upper lip taper in which the upper lip does not return to a normal taper when the upper incisors are retracted. In my opinion, after the lip functions under lip strain conditions for many years its form tends to become permanently altered. In these cases, when the teeth are retracted the lip moves back as fast as the teeth, with the excessive taper remaining. These cases have involved older, nongrowing patients. It is almost impossible to reduce the overjet in such cases and still have an adequate curl left on the upper lip.
Fig. 33 shows an illustrative case. Ten years before the patient began orthodontic treatment, when he was 11 years old, his dentist had removed the four first premolars. Nonextraction treatment at that time might have resulted in a return of the upper lip to normal form instead of the 6 mm. of taper that persisted as the remaining occlusion was made normal. I believe that the stage at which the upper lip no longer returns to normal taper comes at about the same time as the cessation of growth.
Surgical intervention could be considered in the form of a total subapical mandibular osteotomy to move forward the entire lower dental arch as seen in the VTO (Fig. 33, C). Many cases in which serial extractions have been performed without any total treatment planning end up with the lower incisors too far back to allow treatment by conventional orthodontic methods alone. In such cases the patients will never have adequate lip support and harmonious facial balance.
In some older patients there is a partial improvement in the vermilion border measurement, to the extent of 1 or occasionally 2 mm., accompanying orthodontic treatment, so that is all I allow in doing a VTO in such cases.
Occasionally we see a case, nearly always involving a male patient, in which the upper lip grows thicker as part of other facial maturation changes. The patient shown in Fig. 34, A had not received orthodontic treatment but the upper lip, and to some extent the entire profile soft-tissue integumental covering, thickened (Fig. 34, B).
Fig. 35,A, B and C shows a case, treated at 13, in which the upper lip already measured 18 mm.
at the vermilion corder. This type of case is not approached with treatmwnt planning from the soft-tissue VTO. IF one is of the opinion that lower incisor at 52 degrees to Frankfort plane needs to be uprighted to 65 degrees, then extractions will be a necessary part of treatment. I do not now believe that this is indicated.
Fig. 36 shows the same case 14 years later. The lower lip is still 5.5 mm. behind the H line, since it usually does settele back with or following tooth movement, but the upper lip has actually grown thicker and now measures 24 mm. The important thing is to recognize the condition. At retention the upper lip will be full by my standarts, as in preceding case, but they will be in more harmonious relationships than those seen in the present case (Figs. 35 and 36), which was treated to a frankfort mandibular incisor angle of 65 degrees.
My treatment planning is based on the assumption that the upper lip thickness will return to the original measurement with the exceptions that have been discussed. Next is a case (Fig. 37) that was overtreated, even though the patient looked good at the time of retention (Figs. 37, B and 38, B). Why did her upper lip, which measured 16 and 13 mm. originally, end up with measurements of 15 and 10 mm. (Fig. 37, C)? Fig. 37, D shows the follow-up 17 years later. One would expect to see the 17 mm. upper lip measurment at retention and then measurment of 16 and 15 mm. after it had finally adapted. If the upper lip were 5 mm. fuller than it now is, the imbalance between nose and upper lip would be helped a great deal. Even with 4 mm. of lower incisor crowding, the case should be treated on a nonextraction basis rather than being tipped back 3 mm., as done here. If lower second premolars were extracted, the lower molars would have to be moved forward 5.5 mm., and this is almost impossible. Inevitably, the lower incisors will be moved back to some extent while the extraction space is closed.
Superimposition of the forehead, nose, and chin, as seen in Fig. 37, D, shows that the areas that changed were limited to the lips, especially the upper lip, and did not involve nose growth. This might have been minimized if the lower incisors had been left in their original position. Fig. 37, E presents a current VTO showing an upper lip of 15 mm. at the vermilion border, rather than the 10 mm. to which the lip settled in this case. If this patient had been treated to the lower incisor malocclusion position, at least her dentition would have given her 3 mm. more lip support than she now has.
SUMMARY
Ideal facial similarities
Fundamental similarities associated with facial beauty include the following:
1. A soft-tissue chin nicely positioned in the facial profile.
2. No serious skeletal profile convexity problems.
3. An H angle that is within 1 or 2 degrees of average for the convexity measurement of the
individual. (These averages were presented in chart form in Table I).
4. A definite curl or form to the upper lip, measuring in the very narrow range of 4 to 6 mm. in depth of the superior sulcus to the H line and from 2.5 to 4 mm. to a perpendicular line drawn from Frankfort.
5. The lower lip either on the H line or within 1 mm. of it.
6. Lower lip form and sulcus depth harmonious with those of the upper lip, although there was more variation in this area than in the upper lip.
7. No unusually large or small measurements of either-total nose prominence or soft-tissue chin thickness .
We usually make some changes at point A as far as skeletal convexity is concerned. Nearly all of our well-treated patients have a skeletal convexity measurement in the good range at retention. Thus, when treated to a varying H angle according to the convexity of the case, most of our orthodontic patients can be treated by the orthodontist alone and still measure up well on this soft-tissue analysis and in appearance as well. Surgery is indicated mainly in cases of extreme vertical problems and those that need help in the chin area. In the three examples shown in Figs. 39 to 41 the range of convexity varies from 6.5 mm. or – 3 mm. to +3.5 mm., and corresponding to this there is a variation from 7 degrees to 14 degrees in the H angle. There is a natural draping of the soft-tissue profile tissues which harmonizes with the basic skeletal type of the individual. When we try to hide one undesirable trait, such as lack of chin prominence, by retracting anterior teeth too far, we then create a disharmony of the upper lip that is more objectionable than a moderate lack of chin prominence.
Figs. 38, 39, and 40 present three examples of patients from my practice who were treated to these guidelines.
A good soft-tissue facial angle measurement denoting good chin position is present in each, as well as the convexity figure and the corresponding H angle which are all at or very near that suggested in the chart (Table I).
Fig. 1A. The patient was 10 years 6 months of age at the time of the case analysis and 12 years 6 months at the time of retention. This case was selected because it is representative of a large group of orthodontic cases in which patients have disfiguring malocclusions with the potential for correction to ideal facial balance.
Fig. 1B. Cephalometric tracings of patient shown in Fig. 1A. Lines used: 1, The H line or harmony line drawn tangent to the soft-tissue chin and the upper lip; 2, a soft-tissue facial line from soft-tissue nasion to the point on the soft-tissue chin overlying Ricketts' suprapogonion; 3, the usual hard-tissue facial plane; 4, the sella-nasion line; 5, Frankfort horizontal plane (FH); 6, a line running at a right angle to the Frankfort plane down tangent to the vermilion border of the upper lip.
Fig. 10. A, This case has a superior sulcus depth of 10 mm. measured to the H line, but when we observe the depth of the sulcus in relation to a perpendicular from the Frankfort plane to the vermilion border of the upper lip, the measurement is – 3 mm., not a pleasing lip form. B, This Class lll case has a measurement of only 2 mm. to the H line but 6 mm. when measured to a perpendicular line from the Frankfort plane.
Fig. 12. A, There is a 15 mm. measurement of basic upper lip thickness. B, A taper of 1 mm. as shown at retention is the usual finding when the denture is properly oriented and no perioral muscle strain is present with the lips closed.
Fig. 14A. Note in Table I that a 10-degree H angle is ideal when it is found with a 0-degree convexity figure, but it is evident from the excessive depth of the superior sulcus and from the roll of the lower lip outside the H line that a 10-degree angle for this concave skeletal pattern having a – 2.5-degree convexity is not harmonious. It may be noted in the right-hand tracing that a 6-degree H angle is indicated with a – 4 mm. convexity, and this was achieved with the removal of four premolars.
Fig. 16A. Pre- and posttreatment cephalometric tracings. Before- and after-treatment photographs of patient with highly convex skeletal pattern and a lack of chin prominence, treated without surgery.
Fig. 16B. Pre- and posttreatment cephalometric tracings. Before- and after-treatment photographs of patient with highly convex skeletal pattern and a lack of chin prominence, treated without surgery.
Fig. 17
Fig. 17. Extreme variations in the thickness of soft tissues.
Fig. 21A. Chin deficiency causing lower H line to be back and lower lip forward. The retention tracing shows where the soft-tissue chin would need to be advanced to if both lips were used to construct an imaginary H line to determine an
Fig. 24. Lips have a beautiful form, even though the lower incisors are 7 mm. anterior to the bony chin measured to the hard-tissue facial plane. This is usually indicative of lower incisors that need to be uprighted, but here the procumbency is fully compensated by a 16 mm. thickness of the soft-tissue chin in comparison with an 11 mm. thickness of the upper lip.
Fig. 25., A shows a tracing of a Miss America, denoting a winning combination. B, A runner-up Miss Universe contestant. C, A Miss Virginia with a Class II malocclusion.
Fig. 29A. A 13-year-old white male patient who started treatment with protrusion as noted in the 22-degree H angle associated with only 4 mm. convexity and 12 mm. superior sulcus measurement to the H line. The 86-degree chin position is adequate for a case such as this where there is a good growth pattern and a lot of good mandibular growth left to take place. Especially note that there is no evidence of any lip strain to close the lips. The patient has a basic lip thickness of 16 mm. and a measurement from the vermilion border to the upper incisors of 15 mm., which is exactly the usual taper in competent lips that close without strain. At retention we see an increase in upper lip thickness to 20 mm. and a very acceptable profile balance. Excellent mandibular growth has increased the chin prominence to 88 degrees. This was acknowledged as a well-treated case presented at a Tweed Foundation meeting.
Fig. 29B. A 13-year-old white male patient who started treatment with protrusion as noted in the 22-degree H angle associated with only 4 mm. convexity and 12 mm. superior sulcus measurement to the H line. The 86-degree chin position is adequate for a case such as this where there is a good growth pattern and a lot of good mandibular growth left to take place. Especially note that there is no evidence of any lip strain to close the lips. The patient has a basic lip thickness of 16 mm. and a measurement from the vermilion border to the upper incisors of 15 mm., which is exactly the usual taper in competent lips that close without strain. At retention we see an increase in upper lip thickness to 20 mm. and a very acceptable profile balance. Excellent mandibular growth has increased the chin prominence to 88 degrees. This was acknowledged as a well-treated case presented at a Tweed Foundation meeting.
Fig. 30. At follow-up 16 years later the upper lip thickness was back to the original 15 mm. and the disharmony of upper lip to nose was evidenced by inadequate superior sulcus measurements both to the perpendicular to Frankfort and to the H line, denoting a lack of proper lip support from teeth and associated structures. Note also that the soft-tissue facial angle ultimately reached 90 degrees.
Fig. 31. The basic lip thickness is the same as in the last case at 16 mm., but at the vermilion border there is a measurement of only 11 mm. In this case and in many other similar cases there is an actual space between the teeth and the lips at retention.
Fig. 33. After treatment of this type of case the patient no longer must consciously strain the lips to the same extent that was necessary at 10 years of age to bring them together, and this is usually a point of diagnostic difference as to whether or not the condition will improve as the teeth are retracted. When upper premolars are extracted to allow surgical repositioning in older patients, the same response may be seen. This case is both streamlined and dished.
Fig. 34. There is no cause for concern with this type of soft-tissue change. If treatment has been planned properly, there will be no distortion of lips due to lip strain, but the facial features may be prominent as in this case.
Fig. 36. The patient's lower incisors were tipped back. The soft-tissue VTO approach now used would call for them to be left in the malocclusion position.
Fig. 37A-B. Overtreated case that looked good at retention but had unexpected upper lip thinning during and following retention, causing severe facial imbalance.
Fig. 37C-E. Overtreated case that looked good at retention but had unexpected upper lip thinning during and following retention, causing severe facial imbalance.
Fig. 39. Pretreatment and retention photographs of case shown in Fig. 37.
Fig. 40
Fig. 40. Another case in which a nice line-up of lips on H line with pleasing form denotes proper lip support from the teeth and associated structures.
Fig. 41
Fig. 41. Relationship between convexity and H angle indicates proper lip support from teeth and associated structures.
1. Ricketts, Robert M.: Cephalometric synthesis, AM. J. ORTHOD. 46: 647-673, 1960.
2. Tweed, Charles H.: J. Clin. Orthod. 1: 12-20
3. Graber, Lee W.: Lecture, AAO annual meeting, New Orleans, 1980.
4. Hasund, Asbjorn, Wisth, Per J., and Boe, Olav: The H angle in orthodontic diagnosis, study at University of Bergen, Orthodontic Department, supported by Norwegian Research Council Grant B-51.73-0.
5. Jacobsen, Alex, and Sadowsky, Lionel: J. Clin. Orthod. 14: 554-571
