Pre- and Postsurgical Facial Growth in Patients. with Crouzon's and Apert's Syndromes

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1 Pre- and Postsurgical Facial Growth in Patients with Crouzon's and Apert's Syndromes Sven KrRreiBora, D.D.S., Dr. Obpont. HowArRDp Apuss, D.D.S., M.S. Our report deals with 8 patients with Crouzon's and Apert's syndromes followed longitudinally with roentgencephalometric examinations during the growth period. The purpose of the study was to analyze: presur-. gical facial growth, the displacement of the maxillary complex in connection with Le Fort III advancement, the stability of the surgical result, and postsurgical facial growth. Presurgical facial growth was characterized by lack of maxillary sutural growth and abnormal remodeling of the maxilla. The surgical displacement of the maxilla consisted of an average advancement of about 10 mm and a backward rotation. The maxilla remained stable following surgery. However, onlay bone grafts tended to resorb over the long term. Postsurgical facial growth revealed lack of maxillary displacement with development of exophthalmos, relative mandibular prognathism, and malocclusion. However, it was concluded that the positive effects of early craniofacial surgery in patients with severe forms of Crouzon's and Apert's syndromes outweigh these disadvantages. Two main principles are involved in the normal postnatal skeletal craniofacial growth process, i.e., displacement of bones and bone remodeling (Enlow, 1975). The displacement type of growth depends on the presence of normally functioning sutures and synchondroses acting as areas of growth and adjustment, whereas surface remodeling serves to adjust for necessary changes in shape of individual bones. Premature fusion or bridging of craniofacial sutures and synchondroses hinders normal displacement between the bones involved. The syndromes of Crouzon and Apert may, in addition to premature synostosis of calvarial sutures, reveal prema- Dr. Kreiborg is affiliated with the Department of Pediatric Dentistry at The Royal Dental College, Copenhagen, Denmark. Dr. Aduss is affiliated with the Center for Craniofacial Anomalies, Department of Pediatrics, at University of Illinois College of Medicine, Chicago, Illinois. All patients presented in the present report were operated by Dr. Paul Tessier. The authors are frateful to Dr. Tessier for his permission to report on these cases. This paper was presented at the Annual Meeting of the American Cleft Palate Association, New York, May, The study was supported in part by grants from the National Institutes of Health (DE 02872), Maternal and Child Health Service, Department of Health and Human Services, and the Danish Dental Association. ture fusion of the sutures and synchondroses of the cranial base and the sutures of the orbits and the maxillary complex (Greig, 1926; Tessier, 1971, Kreiborg, 1981; Kreiborg and Bjork, 1982; Kreiborg, 1986a). Thus, patients with these syndromes often reveal severe growth disturbances of nearly all craniofacial regions (Kreiborg, 1981; Kreiborg and Pruzansky, 1981). The craniofacial morphology in Crouzon's and Apert's syndromes is somewhat similar, including calvarial deformity, exophthalmos, hypertelorism, and maxillary hypoplasia (Fig. 1). In addition, patients with Apert's syndrome have syndactyly of hands and feet. The premature closure of cranial sutures may constitute a serious clinical problem warranting surgical intervention in infancy to avert pathological effects upon the growing brain and cranial nerves. Over the long term, serious functional and psychosocial problems may ensue as a result of increasingly severe craniofacial deformity. The advent of craniofacial surgery, as pioneered by Dr. Paul Tessier (1967, 1971), has made habilitation of patients with Crouzon's and Apert's syndromes possible. However, very few reports have dealt with the long-term results of this surgery. 78

2 Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH 79 FIGURE 1 A, Boy with Crouzon's syndrome. B, Girl with Apert's syndrome. Note the similarity in craniofacial morphology with calvarial deformity, exophthalmos, hypertelorism, and maxillary hypoplasia. Furthermore, the available information on postsurgical facial growth in children with Crouzon's and Apert's syndrome treated with Le Fort III osteotomies is extremely scarce (Hogeman and Willmar, 1974; Pruzansky, 1982). We were fortunate to have Dr. Paul Tessier, the foremost innovator and most experienced practitioner of craniofacial surgery, operate on a total of eight patients with Crouzon's and Apert's syndrome at Center for Craniofacial Anomalies in Chicago during the years 1972 to Comprehensive longitudinal quantitative data were obtained in all cases both pre- and postsurgically. Two of the patients were operated in early childhood and their postsurgical facial growth was monitored through a 10-year follow-up period. 13 with a range from 7 to 21 observations in the individual cases. All patients except one (#4404) were followed longitudinally during the growth period. Two patients, one from each group, were operated in early childhood. A boy with Crouzon's syndrome (#3263) was operated at 4% years of age and a girl with Apert's syndrome (#3063) was operated at 6% years of age. The remainder of the cases were operated at late adolescence or at adulthood. The average follow-up period after surgery was 6% years with a range from 3 to 10% years. The two patients operated in early childhood had both been followed with annual or biannual observations for more than 10 years after the surgical intervention. METHODS PURPOSE OF STUDY The purpose of the present study was to analyze: 1. presurgical facial growth in patients with Crouzon's and Apert's syndromes 2. the actual displacement of the maxillary complex carried out in connection with the surgical advancement 3. the stability of the surgical result 4. postsurgical facial growth in two children, one with Crouzon's syndrome and one with Apert's syndrome, in terms of subsequent maxillary displacement and remodeling. Sample The sample was longitudinal and comprised a total of eight patients; four with Crouzon's syndrome and four with Apert's syndrome. Six patients were Caucasian and two were Black. The sex, age at examination, age at surgery, and the number of examinations for each patient are indicated in Figures 2 and 3. The youngest patient was aged 4 months at the first examination and the oldest was above 30 years at the last examination. The average number of observations was Surgical Techniques All patients were operated by Dr. Paul Tessier in Chicago, during the years 1972 to Unfortunately, Dr. Tessier was unable to complete all of the required surgery. Therefore, the illustrated results herein do not necessarily represent the full realization of his objectives. Six patients had a Le Fort III monoblock midface advancement (Tessier, 1971). One patient (#2023) had a lower maxillary advancement, and one (#2033) had an isolated advancement of the orbital region, since the occlusion had previously been normalized by orthodontic treatment. In all cases, the advancement of the midface was stabilized by bone grafts to the osteotomy sites. Roentgencephalometry The roentgencephalometric methodologies employed herein are based on the principles and standards described by Broadbent (1931) and modified for infants by Pruzansky and Lis (1958). In addition to the radiographs, dental casts and facial photographs were available. The investigation was supplemented by tomograms and CT

3 <4- C 80 _ The Cleft Palate Journal Supplement, December 1986 CCFANO Q 3196 Q 3263 d I 4404 Q --- o _ AGE IN YEARS : ors I : METALLIC IMPLANTS FIGURE 2 Patients with Crouzon's syndrome. Indication of sex, age at examination, and number of examinations for each individual. The arrows indicate the age at craniofacial surgery. I= insertion of metallic implants in the jaws (Bjork, 1955). CCFA NO Q I LJ O AGE IN YEARS : ors I : METALLIC IMPLANTS FIGURE 3 Patients with Apert's syndrome. Indication of sex, age at examination, and number of examinations for each individual. The arrows indicate the age at craniofacial surgery. I=insertion of metallic implants in the jaws.

4 _ Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH 81 scans as well as other studies to amplify specific findings. In seven of eight cases, metallic implants were placed in the maxillary complex and in a few cases also in the frontal bone at the time of surgery, according to the method described by Bjork (1955). This method has been shown to allow for an accurate analysis of displacement of bones or bone segments and surface remodeling (Bjork and Skieller, 1974, 1976). In two of the seven cases, the metallic implants were lost or proved to be unstable during follow-up. In five cases, the implants were retained throughout the follow-up period. These cases are indicated in Figures 1 and 2. The analysis of facial growth in the cases with metallic implants in the jaws was performed according to the method described by Bjork and Skieller (1974, 1976), and Kreiborg (1981). CCFA Lic cic RESULTS Presurgical Facial Growth Presurgical facial growth could be analyzed in seven of eight patients. In Figure 4, three of these seven cases are illustrated. The presurgical facial growth in two of the Crouzon cases (#2033 and #3263) and in three of the Apert cases (#1031, 2023, 3063) has previously been presented (Kreiborg and Pruzansky, 1981; Kreiborg, 1981). It was characteristic for all seven cases that the maxilla was not being displaced anteriorly in relation to the anterior cranial base during the observation period. The mandible was growing fairly normally, exhibiting a forward rotation in relation to the anterior cranial base, and all patients developed progressive relative mandibular prognathism. The nasal floor was lowered in relation to the anterior cranial base, more so posteriorly than anteriorly. The degree of exophthalmos seemed to increase somewhat, and soft-tissue facial profile reflected the skeletal disharmony between the jaws. Although metallic implants were not employed in this phase of the investigation, it would seem reasonable to conclude that maxillary sutural growth was arrested in all cases and that the observed changes in maxillary morphology could be ascribed to remodeling. A similar abnormal pattern of maxillary growth has previously been shown in Crouzon's syndrome (Kreiborg, 1981). When compared to normative data (Bjork and Skieller, 1976), it would appear that the abnormal remodeling pattern includes excessive resorptive lowering of the nasal floor, especially in the posterior part; excessive appositional growth in height of the alveolar process; bone apposition on the anterior surface of the zygomatic process; lack of bone apposition on the orbital surface or even FIGURE 4 CCFA e CCFA Presurgical facial growth in three cases of Apert's syndrome. Superimpositions were made on stable structures in the anterior cranial base. Note the lack of forward displacement of the maxilla, and the normal mandibular growth creating progressive facial imbalance. 65

5 82 The Cleft Palate Journal Supplement, December 1986 bone resorption; and, finally, the amount of bone apposition at the anterior nasal spine seemed somewhat greater than normal. Surgical Displacement of Maxillary Complex The surgical displacement of the maxillary complex could be analyzed in seven of eight cases. The displacement was defined as the advancement in mm measured in relation to the perpendicular to the Nasion-Sella-line (NSL) and the rotation of the maxillary complex measured in relation to NSL. The results are listed in Tables 1 and 2. In six of seven cases, the maxillary advancement amounted to 9 or 10 mm. In the last case, the advancement was twice as large (19 mm). In six of seven cases, the maxillary complex was rotated backward in relation to the anterior cranial base during surgery. In four of the cases, this rotation was slight (3 to 5 degrees) and in two cases, it was marked (13 to 14 degrees). In a single case, the maxillary complex was rotated slightly forward. Figure 5 illustrates the changes in maxillary position obtained at surgery. In all cases, the surgical procedure included bone grafts to the nose, the glabella region, and the orbital margins. It was characteristic for nearly all cases that the occlusal plane in the maxilla was lowered slightly posteriorly, thereby producing a backward rotation of the mandible. The marked backward rotation of the mandible ob- TABLE 1 Maxillary Displacement at Surgery Maxillary Displacement Advancement" Rotation** Patient No. Group (mm) (degrees) 3196 Crouzon Crouzon Crouzon Apert Apert Apert Apert * Maxillary advancement was measured in relation to the Nasion- Sella-perpendicular (NSP). ** Maxillary rotation was measured in relation to the Nasion-Sellaline (NSL). A positive value indicates a backward rotation and a negative value, a forward rotation. TABLE 2 Mean and Range for Maxillary Advancement and Rotation in Seven Patients with Crouzon's Syndrome and Apert's Syndrome Displacement X Range Advancement 10.9 mm 9-19 mm Rotation served in the case illustrated in Figure 5B was, however, primarily caused by the insertion of an occlusal splint at time of surgery. The sagittal intermaxillary relationship changed dramatically, and in the Le Fort III cases, the orbit to globe relation was markedly improved (Fig. 5). The globe of the eye either stayed in the same sagittal position in relation to the anterior cranial base (Fig. 5A) or it was slightly advanced (Fig. 5B). In the case with the most pronounced maxillary advancement (19 mm), the globe of the eye moved 5 mm forward (Fig. 6). The soft tissue profile was markedly improved in all cases, although the anterior face height, which was enlarged prior to surgery, generally tended to be further increased after treatment. Figures 7 to 10 show the pre- and postsurgical facial photographs in two of the cases, both showing marked improvement in facial balance. Stability of Surgical Result Relapse of the maxillary advancement was not observed in any of the cases. The maxilla remained stable in relation to the anterior cranial base. Minor changes could be observed in the position of the mandible postsurgically in connection with orthodontic treatment. Also, some resorption of onlay bone grafts was recorded (Figs. 11A and B). Postsurgical Facial Growth Facial growth had ceased at the time of surgery in six of the eight cases. However, in two cases (#3063 and 3263) surgery was performed in early childhood. Both cases had metallic implants inserted in the maxilla at the time of surgery, allowing for a precise analysis of subsequent sutural displacement and remodeling of the maxilla. Both cases were followed for a 10-year period after surgery. Their craniofacial growth analyses are illustrated in Figures 12 and 13. The case illustrated in Figure 12 had a surgical maxillary advancement of 19 mm, which led to an overcorrection of the sagittal intermaxillary relationship and the occlusion. The case illustrated in Figure 13 had a surgical maxillary advancement of 10 mm, which proved to be insufficient to correct the malocclusion. In the 10-year follow-up period, the patient with Crouzon's syndrome (Fig. 12) revealed a fairly normal growth of the posterior cranial base (sba). The glabella region had received an onlay bone graft at the time of surgery. This graft was gradually resorbed. However, over the long term the glabella region revealed bone apposition. The maxilla showed no sagittal or vertical sutural displacement in relation to the anterior cranial base

6 ' _ Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH 83 Advancement: 9mm Backward rotation: 4 CCFA PRE-OP 1719 post- op ~ YEAR FOLLOW-UP Advancement: 10mm Backward rotation: 13 FIGURE 5 Surgical displacement of the maxillary complex. Note the lowering of the maxillary occlusal plane posteriorly producing a backward rotation of the mandible. The soft tissue profile shows marked improvement. CCFA 3063 o PRE- OP. 68 PoOST- OP + SPLINT Advancement: 19mm Backward rotation: 3 \ a a - *~ \\ - <\\N N \\ "\ _. \ l\ l I I A ; A FIGURE 6 The patient exhibiting the most marked surgical advancement of the maxillary complex. Note the protrusion of the globe of the eye. ' CCFA 3263 & " PRE-OP. REST POS POST-OP+ SPLINT

7 84 The Cleft Palate Journal Supplement, December 1986 Cccra# AGE 4-8 FIGURE 7 Facial morphology in a boy with Crouzon's syndrome prior to surgery. FIGURE 8 Facial morphology of the patient shown in Figure 7 following the Le Fort III procedure.

8 Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH FIGURE 9 Facial morphology in a girl with Apert's syndrome prior to surgery. ccra# i013? AGE 19-4 as ass e FIGURE 10 Facial morphology of the patient shown in Figure 9 following the Le Fort III procedure. 85

9 86 The Cleft Palate Journal Supplement, December 1986 Advancement : 10mm Backward rotation: 14 CCFA 4404 p ! PRE-OP --~ POST-OP 5-Y EAR FOLLOW-UP Y -A ) A _ CCFA 4404 g 2492 POST-OP YEAR FOLLOW-UP FIGURE 11 Adult patient with Crouzon's syndrome who received a Le Fort III procedure and an advancement of the mandibular symphysis. At 5-year follow-up, the maxilla had remained stable in relation to the anterior cranial base. Some resorption of bone grafts to the glabella region and to the chin was observed at follow-up. FIGURE 12 Postsurgical followup of the boy with Crouzon's syndrome illustrated in Figures 6, 7, and 8. The implant line is indicated in the maxilla. The analysis revealed lack of sagittal and vertical displacement of the maxilla in relation to the anterior cranial base and an abnormal remodeling pattern. CCFA ! POST-OP YEAR FOLLOW-UP

10 _ Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH 87 following surgery, as indicated by the static position of the implant line. The remodeling pattern of the maxilla was abnormal, revealing no change at the orbital surface; bone apposition on the anterior and inferior aspect of the zygomatic process; excessive resorptive lowering of the nasal floor, more so posteriorly than anteriorly; excessive growth in height of the alveolar process. The mandible revealed a relatively normal growth pattern whereby the patient grew into Class III relationship with mandibular overjet. The degree of exophthalmos increased with time, and the patient will require orthognathic surgery following completion of growth. In the 10-year follow-up period, the patient with Apert's syndrome (Fig. 13) revealed lack of growth of the posterior cranial base (s-ba) contributing to mandibular prognathism. The glabella region exhibited marked bone apposition following a short period of bone resorption of the onlay bone graft. The maxilla showed no sagittal or vertical sutural displacement in relation to the anterior cranial base following surgery. The remodeling pattern of the maxilla was abnormal (Fig. 14) and almost identical to the pattern described above for the patient with Crouzon's syndrome. The resorptive lowering of the nasal floor was limited to the posterior region; no resorption was observed in the anterior third, except in the region of the anterior nasal spine. The upper incisors revealed progressive compensatory labial inclination. However, the mandibular growth was of normal magnitude and the patient thereby gradually developed a marked relative mandibular prognathism with Class III maloc- clusion and mandibular overjet. The degree of exophthalmos increased with time because of lack of maxillary growth and the soft tissue profile revealed a progressive disharmony with midface retrusion (Figs. 15 and 16). Facialgrowth ceased at age 16 years in this case, and the patient will require orthognathic surgery in the near future. DISCUSSION The eight patients presented in this report obviously represent moderate to severe forms of Crouzon's and Apert's syndromes since they were selected to have craniofacial surgery. The indications for surgery included: recurrent corneal ulcerations resulting from exophthalmos, increasing vulnerability to eye injury as a result of increasing exophthalmos, chronic otitis and rhinorrhea owing to obstruction of the posterior choanae, early signs of cor pulmonale, and concern about irreversible psychosocial problems. The present study confirms the findings in previous studies (Kreiborg, 1981; Kreiborg and Pruzansky, 1981) as regards facial growth in patients with Crouzon's and Apert's syndromes. There was lack of maxillary sutural growth in all cases; however, the onset of the growth disturbance and its severity varied considerably. The remodeling pattern of the maxilla in the two syndromes could not be accurately analyzed in the present study, since metallic implants in the jaws were not employed in the early phase of the investigation. However, assuming that maxillary sutural growth was arrested in both the sagittal and vertical planes, the remodeling pat- CCFA 3063 ; POST-OP " 10-YEAR FOLLOW-UP FIGURE 13 Postsurgical followup of girl with Apert's syndrome. The implant line is indicated in the maxilla. The analysis revealed lack of sagittal and vertical displacement of the maxilla in relation to the anterior cranial base and an abnormal remodeling pattern.

11 88 The Cleft Palate Journal Supplement, December 1986 FIGURE 14 Illustration of the surgical displacement of the maxilla and the subsequent remodeling of the jaw in the patient shown in Figure 13. Note the marked resorptive lowering of the nasal floor posteriorly and the excessive growth in height of the alveolar process pre -or post-or. 16" 10- YEAR FOLLOW-UP tern was abnormal, resembling the pattern described in a previous implant study of patients with Crouzon's syndrome (Kreiborg, 1981). The remodeling pattern was observed in the two patients in the present study followed during postsurgical facial growth with metallic implants in the maxilla. As previously suggested (Kreiborg, 1981) the lack of sutural growth of the maxilla and the abnormal remodeling pattern lead to a maxilla that is not only small in all three planes of space, but its internal architecture is deranged, e.g., the distance from the orbital floor to the nasal floor is extremely short, and the distance from the nasal floor to the occlusal plane is increased. In the sagittal plane, the distance from the anterior nasal spine to the zygomatic process is foreshortened. The surgical displacement of the maxillary complex in connection with the Le Fort FIGURE 15 Postsurgical facial photographs in the patient shown in Figures 13 and 14, with normalization of facial balance and correction of exophthalmos.

12 Kreiborg and Aduss, PRE- AND POSTSURGICAL FACIAL GROWTH 89 FIGURE 16 Facial photographs of the same patient as shown in Figure 15 at 10-year follow-up. Note the development of relative mandibular prognathism and exophthalmos. III procedure was defined as an advancement of about 10 mm and a backward rotation. Thereby, the sagittal and vertical growth disturbances of the maxilla caused by lack of sutural growth was corrected. However, in nearly all cases, the occlusal plane in the upper jaw was lowered somewhat posteriorly, which was undesirable since it caused the mandible to rotate slightly backward, resulting in further increase of anterior facial height. This complication could probably have been avoided by sectioning the maxilla to correct the basic maxillary deformity described above. In two cases, the maxillary advancement caused the globe of the eye to become slightly protruded, whereas this was not the case in the remainder of the cases. The cause of the protrusion of the globe of the eye could not be evaluated in the present study, but it was noteworthy that the greatest protrusion was observed in the case that underwent the greatest maxillary advancement. Again, this problem could probably have been minimized by sectioning the maxilla, correcting the orbit to globe relation first, followed by correction of the intermaxillary relationship. Facial balance was improved dramatically in all cases, and exophthalmos with its associated hazards to vision was eliminated. As regards the stability of the surgical result, it was a uniform finding that the maxillary advancement remained stable in relation to the cranial base. The retrusive forces on the face are probably of low magnitude, and the inserted bone grafts were apparently able to retain the maxillary complex in its new position. However, onlay bone grafts to the glabella and orbital regions revealed high frequencies of resorption in the total sample. Minor postsurgical changes in mandibular position could be observed in connection with the final orthodontic treatment. Postsurgical facial growth in patients with Crouzon's and Apert's syndromes has been documented in very few previous reports (Hogeman and Willmar, 1974; Pruzansky, 1982). Hogeman and Willmar followed a girl with Crouzon's syndrome for a 4-year period following a Le Fort III procedure. The study included roentgencephalometry and metallic implants in the maxilla. The authors found lack of maxillary sutural growth following surgery, but the remodeling pattern was not examined. Pruzansky (1982) described the postsurgical facial growth of one of the cases which was also included in the present study (# 3063). Pruzansky could only report on a 6-year follow-up period, and he did not include the metallic implant analysis in his discussion. However, he described lack of maxillary sutural growth in the sagittal plane following surgery. The present study revealed lack of sagittal and vertical displacement of the maxilla in relation to the anterior cranial base during a 10-year follow-up period. Furthermore, the remodeling pattern of the maxilla was abnormal, resembling the remodeling pattern observed in unoperated patients as discussed above. The degree of mandibular prognathism was related to the growth pattern of the cranial base as previously discussed by Kreiborg (1986b). Lack of sagittal growth in the middle and posterior cranial base, as observed in cases with extensive synostosis of sutures and synchondroses of the cranial base, will lead to a more pronounced intermaxillary disharmony, as observed in case #3063. Obviously, both cases will require orthognathic surgery at completion of facial growth. However, the surgery needed will probably be limited to a low maxillary advancement with onlay grafts to the orbital region and maybe a mandibular setback in the girl with Apert's syndrome. CONCLUSION Facial growth in the examined patients with Crouzon's and Apert's syndromes was characterized by lack of maxillary sutural growth and an abnormal remodeling pattern of the maxilla. The maxilla thereby became small in all three planes of space, and its internal architecture became deranged. The surgical displacement of the maxil-

13 90 The Cleft Palate Journal Supplement, December 1986 lary complex during the Le Fort III procedure consisted of an average advancement of about 10 mm and a backward rotation. Facial appearance and balance were substantially improved. Exophthalmos was eliminated. However, in a few cases, surgery led to some unwanted protrusion of the globe of the eye in relation to the cranial base. Furthermore, the maxillary advancement tended to include a slight lowering of the maxillary occlusal plane posteriorly leading to an undesired backward rotation of the mandible with further increase in anterior facial height. It is suggested that these problems are related to deranged internal architecture of the maxilla caused by dysplastic growth and that these problems could be avoided by sectioning the maxilla. It would seem reasonable to establish a normal relationship between the globe of the eye and the bony orbit first, followed by a correction of the intermaxillary relationship. The surgical displacement of the maxillary complex remained stable in all cases. However, onlay bone grafts to the glabella and orbital regions and to the chin revealed resorption at long-term follow-up. Postsurgical growth of the maxillary complex in children with Crouzon's and Apert's syndromes was characterized by lack of displacement of the maxilla in relation to the anterior cranial base. The remodeling pattern of the maxilla was abnormal, resembling the remodeling pattern seen prior to surgery. Thus, if maxillary advancement is undertaken in young children with Crouzon's or Apert's syndromes, it must be anticipated that the patients will gradually develop exophthalmos, relative mandibular prognathism, and malocclusion during the remainder of the growth period. The severity of facial disharmony will obviously depend not only on maxillary growth but also on the growth of the cranial base and the mandible. Most patients will probably require orthognathic surgery following completion of growth. However, considering the positive effects of craniofacial surgery (i.e., substantial improvement of facial appearance, with positive effect on the patient's self image and peer group acceptance, and improvement of physical functions during childhood and adolescence), the benefits of early craniofacial surgery in severe cases of Crouzon's and Apert's syndromes outweigh the disadvantages. REFERENCES BJORK A. Facial growth in man studied with the aid of metallic implants. Acta Odontol Scand 1955; 13:9. BJORK A, SKIELLER V. Growth in width of the maxilla studied by the implant method. Scand J Plast Reconstr Surg 1974; 8:26. BJORK A, SKIELLER V. Postnatal growth and development of the maxillary complex. In: McNamara JA Jr., ed. Factors affecting the growth of the midface. Ann Arbor: Center for Human Growth and Development, The University of Michigan, BroApBENT BH. A new x-ray technique and its application to orthodontia. Angle Orthod 1931; 1:45. Entow DH. Handbook of facial growth. Philadelphia: WB Saunders, GREIG DM. Oxycephaly. Edinburgh Med J 1926; 33:198. HogEmMAN KE, WILLMAR K. On Le Fort III osteotomy for Crouzon's disease in children. Report of a four year followup in one patient. Scand J Plast Reconstr Surg 1974; 8:169. KrEIBORG S. Crouzon syndrome. A clinical and roentgencephalometric study. Scand J Plast Reconstr Surg, Suppl 18, KREIBORG S. Postnatal growth and development of the craniofacial complex in premature craniosynostosis. In: Cohen MM Jr., ed. Craniosynostosis: diagnosis, evaluation, and management. New York: Raven Press, 1986a. KrEIBORG S. The cranial base in premature craniosynostosis. Presented at Symposium on Craniosynostosis, University of Virginia Medical Center, Charlottesville, VA, April, 1986b. KrEIBORG S, BJork A. Description of a dry skull with Crouzon syndrome. Scand J Plast Reconstr Surg 1982; 16:245. KREIBORG S, PRUZANsKY S. Craniofacial growth in patients with premature craniosynostosis. Scand J Plast Reconstr Surg 1981; 15:171. PrRUZANsKkY S. Craniofacial surgery: the experiment on nature's experiment. Eur J Orthod 1982; 4:151. PRUZANSKY S, Lis EF. Cephalometric roentgenography of infants: sedation, instrumentation, and research. Am J Orthod 1958; 44:159. TEssiEr P. Ostéotomies totales de la face; syndrome de Crouzon; syndrome d'apert; oxycéphalies, scaphocephalies, turric ephalies. Ann Chir Plast 1967; 12:273. TrEssiER P. The definitive plastic surgical treatment of the severe facial deformities of craniofacial dysostosis. Crouzon's and Apert's disease. Plast Reconstr Surg 1971; 48:419.