Treatment Variables Affecting Facial Growth in Complete. Unilateral Cleft Lip and Palate. Part 7: An Overview of Treatment.

Transcription

1 Treatment Variables Affecting Facial Growth in Complete Unilateral Cleft Lip and Palate. Part 7: An Overview of Treatment and Facial Growth Facial growth in a sample of 538 males with complete unilateral cleft lip and palate was evaluated by means of cephalometric radiographs. There were subtle but significant differences in growth attributable to differences in the treatment provided. Repair of the alveolus in infancy, especially using bone grafts, had undesirable effects. Repair of the hard palate appeared to be the major influence on maxillary forward translation and development of the dentoalveolar process. Variation in the timing and technique of hard palate repair within the first decade did not affect the result appreciably. Circumstantial evidence suggested that the surgeon was the most important variable. Facial growth is a complex phenomenon, governed for the most part by genetic factors and modified by developmental and environmental influences. One set of modifying influences is a cleft of the lip and palate and the corrective procedures that ensue. Many clinical strategies have been proposed to encourage growth or to reduce growth inhibition, and this study was intended to examine the growth response to these strategies. The results were often surprising and will be disturbing to many clinicians. The study was a unique example of cooperativeresearch. The enormous numbers of subjects available for analysis gave a credence to the results that is not possible with smaller samples. The analysis was completely unbiased, since tracing and digitizing were performed by Mrs. Lynn Cornfoot with remarkable diligence and precision and with complete unconcern for the source of the radiographs. I am very grateful for her contribution to the study. The clinical significance of the data may be unacceptable to many, since the differences noted were often slight and not very impressive to clinicians accustomed to accepting compromise in one area to gain advantage in another. A millimeter less growth will not be an overwhelming inducement for most surgeons to change the operative procedures that they believe in and are comfortable with. One may be tempted to think that the observed treatment-induced differences are like those in a world cup ski race, much too small to be observed without the aid of the most sophisticated measuring techniques. Minor differences must be taken in context, however, and the context of unilateral cleft lip and palate males is one of an extremely precarious growth situation. In a review of one hundred adult _ 71 unilateral cleft lip and palate (UCLP) cases in our Center, it was estimated that 45 percent of the adult males had required routine orthodontic treatment, 28 percent required difficult, compromise orthodontic treatment, and 27 percent should have received orthognathic surgery for esthetic or functional reasons. In a normal population, almost everyone has reasonably acceptable jaw relations, and routine orthodontic treatment can manage all but the most severe. A population of UCLP individuals, however, will have a distribution such as that seen in Figure 1, with the majority of children having borderline-adequate jaw relations, on the threshold for orthognathic surgery. One measure of jaw relationships is the ANB angle (Fig. 2A). The individuals within one standard deviation of the mean have favorable jaw relations that require routine orthodontic treatment. The individuals falling between one and two standard deviations have less favorable relations, and orthodontic treatment is more difficult. Individuals falling outside of two standard deviations would usually require or benefit from orthognathic surgery. Figure 2B has the mean and one standard deviation for UCLP males superimposed on the normal, illustrating the progressive decrease in the ANB angle with age in UCLP males; the decreasing angle represents a deterioration in skeletal jaw relations. Obviously, many more individuals reach the zone where orthognathic surgery is required. Although a change of one degree is of little significance to the individual, it is easy to visualize from Figures 1 and 2 the result of a positive or negative shift of even one degree in jaw relations. In theory at least, the 27 percent of cases that I considered would have benefited from orthog-

2 72 Cleft Palate Journal, January 1987, Vol. 24 No. 1 Facial Development In Cleft Lip And Palate With Average Treatment consequently involve extra expense and general stress. It is incumbent on those who use such procedures to prove that there are increased benefits. The goal of achieving excellent speech should be a major criteria, but hard data are very scarce, and more research from the speech scientists is required. The indications are that hard and soft Threshold -surgery Mediocre Excellent palate repair prior to 1 yearof age is highly desirable. Growth considerations in the past have led most surgeons to avoid such early repair. DISCUSSION FIGURE 1 A hypothetical distribution of jaw relations in a population of individuals with unilateral cleft lip and palate. The bulk of the sample have mediocre jaw relations, and a sizable portion require orthognathic surgery. A shift of the curve in either direction would cause a large change in the number of individuals requiring orthognathic surgery. nathic surgery might be increased to 33 percent or decreased to 20 percent by a relatively slight change in the mean growth pattern. If it is possible to enhance the average growth pattern, even slightly, it is unquestionably worthwhile. Another aspect of treatment that must be considered is the efficiency of treatment. If two methods provide identical results, but one is simple and the other is complex, it would seem to be common sense to adopt the simple method. There are many examples of multiple surgical procedures or multiple orthodontic appliances or treatments which require a long-term effort by the patient, the parents, and the clinician, and Intrinsic Growth Problems There appears to be a basic intrinsic deficiency in the midfacial skeleton in individuals with UCLP. The present study is not definitive in this regard, since there was no comparison of unoperated to normal samples, and the following details are somewhat theoretical. The two groups receiving the least amount of surgery (Marburg and Unoperated) did have repairs to the cleft lip and in the former, the soft palate. Disregarding for the moment the possible effects of lip repair, the conclusion reached was that the maxilla in the unilateral cleft subject is not more posteriorly positioned to any appreciable extent, but is much shorter in length than in noncleft individuals (almost 3% millimeters shorter at 17 years of age, using the anterior nasal spine). The difference, surprisingly, was not so marked when A point was used as the anterior limit of the maxilla, suggesting that: (a) NORMAL MALES BURLINGTON GROWTH CENTRE MALE UNILATERAL CLP n= 952 tag 2 -a - LI AGE (YEARS) G AGE (YEARS) FIGURE 2 A, Mean values with one and two standard deviations for the ANB (A point-nasion-b point) angle. B, The heavy line superimposed on the normal graph indicates the mean and standard deviation for a large sample of males with unilateral cleft lip and palate.

3 Ross, OvERvIEW or TREATMENT 73 anterior nasal spine is deficient in a cleft; (b) anterior nasal spine is disturbed by the lip repair; (c) the repaired lip affects the basal maxilla more than the alveolar process; or (d) the accommodating capabilities of the alveolar process are functioning well, even after lip repair. My personal opinion is that the last possibility should be favored. The vertical development of the maxilla is slightly deficient posteriorly (or quite deficient if measured from sella) and less so anteriorly. The mandible, also shorter, is more open, giving a decreased midface-lower face ratio in facial height. Surgically-Induced Growth Problems When the total sample of treated UCLP cases was compared to the noncleft group, more severe differences in skeletal morphology were noted, and these must have resulted from repair of the hard and soft palate. Average palate surgery resulted in a posterior displacement of the maxilla (really an inhibition of its forward translation during growth), further slight shortening of maxillary basal length, and marked retrusion of the alveolar process. Palate repair induced a reduction in posterior maxillary height, but no anterior vertical changes were noted, including the midface proportion of total face height. Variation in Surgically-Induced Growth Problems Given that intrinsic growth problems exist and are exacerbated by surgery, the next question is how much difference can there be between different methods? The differences noted in Figure 1 of Part 3 were more extreme than the differences between cleft and noncleft groups, so the answer is that different surgery can cause great difference in growth of the facial skeleton. The variations noted throughout this study were subtle because these children received excellent surgery. It would not be difficult to locate many samples in the world in whom the surgery was not so well done and greater deviation from the average would be encountered. If the reader will forgive another athletic analogy, these samples were like an Olympic 1,500-meter final, and although differences were obvious, the overall quality was excellent. Generalizations about treatment supported by the data were that there was no effect on the cranial base, the temporomandibular joint location, mandibular length, dentoalveolar eruption, or the angulation and position of the occlusal plane. The length of the mandible was variable be- - tween small samples, but large samples of any particular method of treatment were associated with equal-sized mandibles. The size of the mandible was not highly correlated to maxillary size. Lower face height was also variable, but protrusion of the chin point was much less variable, leading to the hypothesis that the mandible established an open or closed position related to its length and the size of the maxilla in order to achieve the most favorable occlusion. The important variables that were affected by treatment were obviously the position and size of the maxilla and the position of the mandible. Specific Effects of Treatment The newborn with unilateral cleft lip and palate requires numerous clinical procedures before habilitation is complete. The following discussion will attempt to analyze each procedure with regard to its effect on growth. Infant Presurgical Orthopaedic Treatment. The application of pressure or guidance to the maxillary segments in infancy had no longterm effect on maxillary morphology. This was true whether the orthopaedic treatment was rapid repositioning prior to early lip surgery, or longterm guidance into the primary dentition. The present study did not investigate the transverse dimensions or positioning of individual teeth, but there is no evidence to presume that these parameters are altered in the permanent dentition either. One sample had used extraoral strapping, and there was a marked retrusion of the dentoalveolar process noted in the permanent dentition. This could have been related to the small size of the sample or possibly to especially traumatic lip surgery. Since extraoral strapping is not necessary to achieve the goals of presurgical orthopaedic treatment, however, it would seem prudent to avoid its use. Repair of the Cleft Lip. Cleft lip repair is primarily a cosmetic procedure and should be judged on this basis. The effect of lip repair on midface growth is unknown, although following lip repair the anterior maxilla on the noncleft side is quickly molded back, bringing the maxillary midline closer to the midline of the face. There is probably a long-term, mildly inhibitory influence on the growth of the maxilla with any lip repair. Obviously, an unrepaired lip would permit an uninhibited, perhaps even excessive forward growth of the maxilla, particularly the dentoalveolar process, even more than a normal lip would permit. This could account for the excellent midface development noted in unoperated cases.

4 74 Cleft Palate Journal, January 1987, Vol. 24 No. 1 Clinicians treating individuals with unilateral cleft lip and palate are aware that there is a strong correlation between a very tight, hypertonic lip and a collapsed maxilla and maxillary dental arch. Fortunately, this troublesome situation is not often encountered. It is possible that some techniques would produce a tight lip with stronger compression forces on the maxilla, but this was not observed in the study. Even such local effects as incisor eruption patterns did not appear to be influenced by the type of lip repair or the surgeon. There was a suspicion that very early lip repair was associated with less desirable maxillary development. This should be investigated with large and earlier-operated samples. Repair of the Alveolus. Repair of the alveolus had a marked effect on the anterior maxilla, particularly in the vertical dimension. Given that there is mediocre anteroposterior and vertical development of the maxilla, alveolus repair should be postponed or avoided, especially in individuals with a poor growth potential. Reduced maxillary length (PMP-ANS) is an indicator of an inhibitory growth effect. A survey from Part 1 showed that in the seven samples with the greatest maxillary length there were none with bone grafts, two with alveolus repair, and the remaining five with no alveolus repair. In the seven samples with the least maxillary length, five had bone grafts, and a sixth had alveolus repair. It must be noted, however, that five of the worst seven were Scandinavian samples (plus Chicago and Australia); only one of the best seven (from Denmark) was from this ethnic area. The others were from Canada, Switzerland, and New Zealand. An ethnic connection could be suspected as influencing the data if one theorizes that Scandinavians have naturally shorter maxillas. A study by Kerr and Ford (1986), however, showed that Swedish boys at 10 and 15 years had greater maxillary protrusion than Scottish or Irish boys, which voids a theory of Scandinavian maxillary size reduction. There are two consequences of inadequate vertical maxillary development: (1) deficient midface height results in poor facial vertical proportions; and (2) poor vertical height of the anterior nasal spine results in a more acute nasolabial angle. Figure 3 illustrates that the combination of midface retrusion, acute nasolabial angle, and relatively excessive lower face height contribute greatly to the unattractive cleft lip facies. There are, however, decided advantages to a bone-grafted alveolus and anterior maxilla. These advantages are fully attained if the graft is placed at 9 to 11 years of age (Bergland et al, 1986); there FIGURE 3 A severe example of the typical facial features found in males with unilateral cleft lip and palate. are no apparent indications for performing this procedure earlier. The onus now shifts to those surgeons who repair the alveolus in infancy to justify a procedure that causes unfavorable growth without offering any apparent advantage over later repairs. If the speech scientists consider that some benefit accrues from early alveolus repair and provide hard data as evidence, then that would be a most important factor in the decision. Hard and Soft Palate Repair. These procedures provide the greatest potential for inhibiting the maxilla in length, forward translation, and posterior height. The forward translation of the maxilla during growth, indicated by the depth of the pharynx (Ba-PMP), does not appear to be affected by any particular method of repair unless a severe growth retardation is encountered, such as occurred with the very large bone graft formerly used in Goteborg. Palate repair inhibits forward translation of the maxilla, but all palate repairs inhibit forward translation more or less equally. Posterior maxillary height (P-PMP) is also decreased by palate repair, but not consistently. Some procedures have a greater effect than others, although there does not seem to be any clinical importance to a variation in this dimension. It does not, for example, influence the ver-

5 Ross, OvERvIEW or TREATMENT 75 tical position of the occlusal plane, which is established by the amount of molar eruption and the posture of the mandible. Figure 6 in Part 5 is a good illustration of this. The anteroposterior length of the maxilla, whether determined from anterior nasal spine or A point, is probably the most critical maxillary - dimension affecting facial esthetics and the occlusion of the teeth. In this study there was an obvious intrinsic defect, an unknown lip repair effect, and a moderate variation amongst the samples. The dentoalveolar process of the maxilla, consisting of the teeth and their supporting bone, is very sensitive to pressure, and the position of the incisal edges of teeth are easily altered in response to even slight changes in the local environment. The position of the root apices of the incisors, however, are much less vulnerable, but can still be affected. Lip repair creates a labial pressure, and anterior palate repair can create a palatal tension which could cause a retrusion of the entire dentoalveolar process. Orthodontic treatment can advance the incisal edges to compensate for maxillary underdevelopment, but the apices cannot be advanced. The position of point A on the maxilla provides a good approximation of the anterior limit of the incisor apices. The effective length of the maxilla (PMP-A Pt) includes both basal maxillary length and the position of the alveolus on it. Table 1 presents a selected group of samples from the study with their approximate maxillary lengths at age 16 years. The data indicate that maxillas in Unoperated Hard Palate cases are longest (46.4 mm), with Lindsay cases (regardless of the type of palate repair) not far behind at 45.9 mm. Comparing the general pushback (43.3 mm), other Toronto pushback (44.5), and miscellaneous palate repairs (44.7 mm) as well as the total Van Langenbeck repairs (43.9 mm), it would seem that the specific technique being used is probably not important. A long maxilla is also found in Auckland cases, early palate repair cases (which were mostly from Auckland), and Tennison and medium-age or late repaired lips. Soft tissue alveolus repair or no alveolus repair cases had above-average maxillary length. Below average maxillary lengths were noted in the alveolar bone grafted cases. The delayed hard palate repair and the orthopaedic group with strapping had shorter maxillas, but the latter group composed half of the former. The late palate repair group and the early and Millard lip repair group also had below-average maxillary length. The forward translation of the maxilla and the length of the basal bone are probably influenced TABLE 1 Approximated Length of Maxilla (PMP-A Point) in Selected Groups, Adjusted to the Cranial Base Length (Ba-N)* Group Length of Maxilla (mm) Normal sample 47.5 Unoperated hard palate 46.4 Lindsay Von Langenbeck palate repair 45.9 Lindsay pushback palate repair 45.8 Early palate repair 45.0 Tennison lip repair 45.0 Auckland cases 45.0 Soft tissue alveolus repair 44.8 Miscellaneous palate repair 44.8 Medium-age lip repair 44.7 One-stage palate repair 44.7 No alveolus repair 44.5 Late lip repair 44.5 Toronto pushback palate repair 44.5 Copenhagen sample 44,3 Toronto orthopaedic sample 44.2 Medium-age palate repair 44.2 All clefts in sample 44.2 Le Mesurier lip repair 44.1 Toronto Base 44.0 Passive orthopaedic treatment 44.0 Von Langenbeck palate repair 43.9 Two-stage palate repair 43.8 Millard lip repair 43.7 Chicago sample 43.6 Uppsala sample 43.5 Late palate repair 43.5 Early palate repair 43.4 Other pushback palate repair 43.4 Strapping orthopaedic treatment 43.4 Perth sample 43.4 Delayed hard palate repair 43.4 Malmo sample 43.2 Infant bone graft 43.2 Stockholm sample 43.1 Skoog lip repair 43.0 Oslo sample 43.0 Goteborg sample 38.3 * In UCLP this measurement decreases by approximately 0.25 mm per year, so the measurements are given at an estimated 16 years of age. by the same forces, and when combined give a good indication of anteroposterior growth. One measurement that reflects these two variables was the angle of maxillary protrusion (Ba-N-ANS). Table 2 presents some of these measurements related to the Toronto Standard. There is often a change in this angle with growth if a group is growing better or worse than the Toronto Standard (for example, the Normals improved 2 degrees from 11 to 16 years of age, but the Toronto Base cases worsened 0.5 degrees from 11 to 16 years of age). The younger groups are, therefore, less reliable. It seems clear that the most favorable protrusion resulted from the Unoperated

6 76 Cleft Palate Journal, January 1987, Vol. 24 No. 1 TABLE 2 Degree of Maxillary Basal Protrusion (Ba-N- ANS Angle) in Selected Groups, Expressed as + Toronto Standard* Protrusion + Toronto Mean Standard Group Age (degrees) Normal Unoperated hard palate Lindsay Von Langenbeck procedure Lindsay pushback palate repair Auckland sample Medium-age lip repair (no alveolus repair) Early palate repair Lindsay "no orthopaedics" Miscellaneous palate repair Tennison lip repair (no alveolus repair) Lindsay "orthopaedics": Soft tissue alveolus repair Toronto orthopaedic sample Late lip repair Late lip repair and alveolus repair Medium-age lip repair Medium-age palate repair All clefts in sample One-stage palate repair Two-stage palate repair Tennison lip repair and alveolus repair Toronto pushback sample All alveolus repair No alveolus repair Pushback palate repair Passive orthopaedic treatment Other pushback procedures Early lip repair Millard lip repair Late palate repair Le Mesurier lip repair 15 -QO.1 Von Langenbeck palate repair Delayed hard palate repair All bone graft cases Stockholm sample Toronto Base sample _ Strapping orthopaedic treatment Perth sample Uppsala sample Infant bone graft Malmo sample Oslo sample Chicago sample Goteborg sample 16-5.] * The Toronto Standard at age 15 years is 63 degrees. Hard Palate, the Lindsay and Auckland groups; the medium age lip repair without alveolus repair group (mostly from Lindsay or Toronto Orthopaedic) or early palate repair group (mostly Auckland cases). The least favorable maxillary protrusions were in the bone grafted cases, Malmo and Perth samples, orthopaedically strapped cases, the Von Langenbeck palate repair group, and the delayed hard palate repair group (many of whom were orthopaedically strapped). The early lip repair group were worse than the medium or late lip repair groups, but alveolus repair was somewhat of a factor here. The Surgeon As the data were assembled, there were few clearcut explanations for the variability of the results. The best facial development was observed in the Toronto cases operated by Lindsay, and perhaps an analysis of his procedures would be enlightening. There were too many cases (N=56) for a sample fluke to have occurred. It seems equally unlikely that the ethnic background was responsible, since the sample (judging by surnames) was mixed western European. The presurgical orthopaedic treatment did not help, since those receiving orthopaedic treatment were slightly worse than the others. Could it be the timing or technique of lip repair and palate repair? Certainly not the timing of these procedures, since they were invariably performed at the traditional 3-month and 18-month ages respectively. The lip repair was either a rectangular flap or lower triangular flap, neither being unusual in design. There were no growth differences between Lindsays pushback palatoplasty patients and his Von Langenbeck palatoplasty patients. Significantly, however, both groups had better growth results than other examples of pushback or Von Langenbeck palatoplasty. The alveolus and anterior palate in the region of the alveolus were not repaired, and this could be a significant factor. The orthodontic treatment provided in our clinic could have helped growth; that factor was investigated but also turned out to be of no importance. The conclusion is unavoidable that Lindsays technique, although apparently very traditional, does avoid much of the subsequent growth inhibition that is usually encountered in children with unilateral cleft lip and palate. The explanation may well be that this is a reflection of unusual care and gentleness in the manipulation of the soft tissues. A previous study had shown that the very earliest group of Lindsay cases did not have the excellent facial growth of his later cases, indicating that experience is an important factor as well. Surgeons would do well to develop "soft hands" when operating in this area, because that is probably the key to success. Another group with excellent maxillary growth was the Auckland sample. There were marked differences in technique between these cases surgically treated by Dr. Manchester and the Lindsay cases. The hard and soft palates were repaired in two stages, prior to 1 year of age. The alveolus was not only repaired, but bone grafts were inserted in a sizable number of cases at ages 4 through 7 years. These management procedures - would be expected to result in less than satisfactory results, but such was not the case. Again, there is a suspicion that tissue management may

7 Ross, OvERvVvIEW OF TREATMENT 77 be much moreimportant than the techniques being used. SUMMARY AND CONCLUSIONS The unequivocal findings in this study were as follows: 1. There is an intrinsic deficiency in the facial skeleton of males with complete unilateral cleft lip and palate that is exacerbated by surgical repairs. 2. Early repair of the alveolar cleft causes marked changes in the vertical development of the maxilla and in the facial vertical proportions. Bone grafting the alveolus worsens the problem and influences anteroposterior growth as well. It would seem that with the large number of borderline growth problems in the cleft population, these procedures should be avoided or delayed until the individuals growth pattern is manifest or until growth prediction methods have improved. 3. Other than early repair of the alveolar cleft, the type of surgical repair used does not make an appreciable difference to facial growth. It appears, however, that there are differences that can only be explained on the assumption that some surgeons induce less growth inhibition than others. 4. Variations in the timing of hard and soft palate repair within the first decade do not influence facial growth in the anteroposterior or vertical dimensions. Since there is no evidence that the transverse dimension is improved either, surgeons should repair the hard and soft palate when it is in the best interest of the child. Speech and psychosocial factors should determine the most appropriate time to act. One caution: very early hard palate surgery was not well represented in this study, and there is some suspicion that there might be untoward results. 5. There is every indication that for facial growth the most simple treatment is as effective as any other. Complex treatment that necessitates multiple surgical and orthodontic procedures should be justified on the basis of other criteria. References BERGLAND O, SEMB G, AABYHOLM F. Elimination of residual alveolar cleft by secondary bone grafting and subsequent orthodontic treatment. Cleft Palate J 1986; 23:175. KERR WJS, Forp I. A comparison of facial form in three: western European male groups. Eur J Orthod 1986; 8:106.