Apert's and Crouzon's Syndromes Contrasted: Qualitative Craniofacial X-Ray Findings* Sven Kreiborg (Copenhagen), Howard Aduss (Chicago), and M.Michael Cohen, Jr. (Halifax)

Introduction caused by the same genetic defect (Escobar and Bixler 1977). Both syndromes are rare. Consequently, most Apert's and Crouzon's syndromes are both char• reports in the literature deal with isolated cases, acterized by premature of craniofacial and the findings are primarily related to the spe• sutures. In addition, patients with Apert's syn• cial field of the individual author. However, a drome have of the hands and feet. comprehensive description of the craniofacial Both syndromes are transmitted as autosomal morphology and growth in a relatively large sam• dominants. The craniofacial morphology in the ple of patients with Crouzon's syndrome has been two syndromes is somewhat similar, including ex• given elsewhere (Kreiborg 1981). ophthalmos and midfacial hypoplasia (Figs. 1, 2), The purpose of the present study was to com• and it has been suggested that the two diseases are pare the frequencies of several anomalous cranio• facial skeletal traits in the two syndromes, in an * The work described in this paper was supported by effort to contribute to the understanding of their grants from NIDR (DE-02872) and the Nato Science Fel• natural history. lowship Programme (23.03.32/ 84).

Fig.1. Boy 8 years of age with Apert's syndrome Fig. 2. Boy 8 years and 7 months of age with Crouzon's syndrome

D. Marchac (ed.), © Springer-Verlag Berlin Heidelberg 1987 92 S. Kreiborg et al.

Materials and Methods 61 patients with Crouzon's syndrome. The sex dis• tribution and the age range in the two samples are given in Table 1. The Crouzon's sample has been described in de• tail previously (Kreiborg 1981). To obtain a suffi• cient number of patients with Apert's syndrome, Table 1. Sex distribution and age range in the two groups data from three centers were pooled. The data ori• examined ginated from The Royal Dental College in Co• penhagen, the University of Illinois College of Group n Male Female Age range (years) Medicine in Chicago, and Dalhousie University n % n % in Halifax. Both samples were mixed longitudinal, com• Apert's 60 27 45.0 33 55.0 0-36 Crouzon's 61 33 54.1 28 45.9 0-74 prising 60 patients with Apert's syndrome and

6. Fig. 3. a Frontal and b lateral cephalomet• ric films of a Crouzon's patient. Note: syn• ostosis of all calvarial sutures; increased digital markings; deviation of the nasal septum; obstruction of nasopharynx

Fig. 4. Calcification of the stylohyoid liga• ment in a patient with Crouzon's syndrome Apert's and Crouzon's Syndromes Contrasted: Qualitative Craniofacial X-Ray Findings 93

Fig. 5. Fusion of cervical vertebrae (C-2 and C-3) in Crou• Fig.6. Frontal protrusion with wide open metopic suture zon's syndrome in infant with Apert's syndrome

The material included roentgen cephalometric Table 2. Fused sutures in patients below 30 years of age films in the lateral and frontal projections in near• Sutures Group n REC PCT ly all cases, supplemented by conventional head films. Coronal Apert's 57 57 100.0 The anomalous craniofacial skeletal traits re• Crouzon's 45 47 95.7 corded included premature synostosis of the coro• Sagittal Apert's 43 50 86.0 nal, sagittal, and lambdoidal sutures; increased Crouzon's 46 47 97.9 digital markings; deviation of the nasal septum; Lambdoidal Apert's 45 57 78.9 obstruction of the nasopharynx; calcification of Crouzon's 37 47 78.7 the stylohyoid ligament; and fusion of cervical REC, recordable in (no. of patients); PCT, percentage vertebrae (Figs. 3 - 5). Statistical testing of the ob• served frequencies in the groups was carried out using Fisher's exact test.

that infants with Apert's syndrome had protru• Results sion of the and a wide open metopic suture in nearly all cases examined (Fig. 6), where• as these findings were rare in infants with Crou• The results are presented in Tables 2-5. The anal• zon's syndrome. ysis of X-rays of patients below 30 years of age re• Frequencies of increased digital markings were vealed uniform and extremely high frequencies of higher in Crouzon's than in Apert's syndrome complex premature synostosis of calvarial sutures (Table 3). The difference was not significant at the in both groups (Table 2). It was found, however, 1 % level, however. 94 S. Kreiborg et al.

Deviation of the nasal septum was assessed in Apert's patients more often revealed fusions of 67% of the Apert's syndrome patients, compared several vertebrae, and the most common localiza• with 33% of those with Crouzon's syndrome tion of fusion was between C-5 and C-6. In con• (Table 3). This difference was highly significant trast, in Crouzon's syndrome the most common (P < 0.001). Obstruction of the nasopharynx and, fusion recorded was between C-2 and C-3. especially, calcification ofthe stylohyoid ligament were common in both syndromes (Table 3), and the differences between the two groups were not significant at the 1 % level. Discussion Fusion of cervical vertebrae was assessed sig• nificantly more often in patients with Apert's syn• drome than in patients with Crouzon's syndrome All traits recorded were common in both syn• (Table 4). Furthermore, the distribution of fused dromes. Complex synostosis of calvarial sutures vertebrae varied in the two groups (Table 5). in Apert's and Crouzon's syndrome is probably related to a generalized synostosis of sutures and synchondroses in the craniofacial complex (Krei• borg 1981; Ousterhout and Melsen 1982; Krei• Table 3. Qualitative X-ray findings borg and Bjork 1981). Trait Group n REC PCT The presence of a wide open metopic suture and frontal protrusion in infants with Apert's syn• 79.7 Increased digital Apert's 47 59 drome has been reported previously (Kreiborg markings Crouzon's 56 61 91.8 and Pruzansky 1981) and seems to be syndrome Deviation of nasal Apert's 35 52 67.3*** specific. The high frequency of obstruction of the septum Crouzon's 20 60 33.3 nasopharynx can be explained by the maxillary Obstruction of na- Apert's 27 59 45.8 hypoplasia caused by premature fusion of maxil• sopharynx Crouzon's 18 60 30.0 lary sutures (Kreiborg 1981, 1986). Calcification of Apert's 40 57 70.2 The significantly higher frequency of deviation stylohyoid ligament Crouzon's 53 60 88.3 of the nasal septum in Apert's syndrome is prob• *** P

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