Purpose: Craniofacial morphology and growth comparisons in children with untreated nonsyndromic Robin Sequence (RS) and a control group with unilateral incomplete cleft lip (UICL) in which the lip was surgically closed at 2 months of age. Material: The 52 children (7 RS and 45 UICL) included in the study were drawn from a group representing all Danish cleft children born 1976 through 1981. The ages of the children were 2 and 22 months at the time of examination 1 and 2, respectively. Method: The method of investigation was three-projection cephalometry. Craniofacial morphology was analyzed by means of linear, angular, and area variables. Growth at a specific anatomical location in a patient was defined as the displacement vector from the coordinate of the corresponding landmark at examination 1 to its coordinate at examination 2. Results: The most striking findings in the RS group were markedly increased posterior maxillary width, increased width of the nasal cavity, short maxilla with reduced posterior height, short mandible, bimaxillary retrognathia, and severe reduction in size of the pharyngeal airway. The amount of facial growth was similar in the two groups; however, a tendency toward a more vertical growth direction was observed in the RS group. Conclusion: Facial morphology in children with RS differed significantly from that of children with UICL at both 2 and 22 months of age. The magnitude of facial growth was similar in the two groups, whereas a tendency toward a more vertical facial growth direction was observed in the RS group.

Crouzon syndrome is characterized by premature fusion of sutures and synchondroses. Recently, the first mouse model of the syndrome was generated, having the mutation Cys342Tyr in Fgfr2c, equivalent to the most common human Crouzon/Pfeiffer syndrome mutation. In this study, a set of micro-computed tomography (CT) scannings of the skulls of wild-type mice and Crouzon mice were analysed with respect to the dysmorphology caused by Crouzon syndrome. A computational craniofacial atlas was built automatically from the set of wild-type mouse micro-CT volumes using (1) affine and (2) non-rigid image registration. Subsequently, the atlas was deformed to match each subject from the two groups of mice. The accuracy of these registrations was measured by a comparison of manually placed landmarks from two different observers and automatically assessed landmarks. Both of the automatic approaches were within the interobserver accuracy for normal specimens, and the non-rigid approach was within the interobserver accuracy for the Crouzon specimens. Four linear measurements, skull length, height and width and interorbital distance, were carried out automatically using the two different approaches. Both automatic approaches assessed the skull length, width and height accurately for both groups of mice. The non-rigid approach measured the interorbital distance accurately for both groups while the affine approach failed to assess this parameter for both groups. Using the full capability of the non-rigid approach, local displacements obtained when registering the non-rigid wild-type atlas to a non-rigid Crouzon mouse atlas were determined on the surface of the wild-type atlas. This revealed a 0.6-mm bending in the nasal region and a 0.8-mm shortening of the zygoma, which are similar to characteristics previously reported in humans. The most striking finding of this analysis was an angulation of approximately 0.6 mm of the cranial base, which has not been reported in humans. Comparing the two different methodologies, it is concluded that the non-rigid approach is the best way to assess linear skull parameters automatically. Furthermore, the non-rigid approach is essential when it comes to analysing local, non-linear shape differences.

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Objective. To investigate and compare facial asymmetry in subjects with JIA with unilateral, bilateral or no TM joint (TMJ) involvement. Methods. Eighty-one subjects with JIA: 22 with unilateral TMJ involvement (Group 1), 15 with bilateral TMJ involvement (Group 2) and 44 with no TMJ involvement (Group 3). Panoramic X-rays and three-dimensional (3D) photographs (surface scans) were obtained for all subjects. Panoramic X-rays were rated for severity of TMJ involvement. For each individual, a spatially detailed facial asymmetry map was created from the 3D photograph. Mean and variability of asymmetry were calculated for each of the three groups and compared. Results. Distinct patterns of asymmetry were found in Groups 1 and 2. With mean asymmetry values up to 3.5 mm, Group 1 exhibited a significantly greater amount of asymmetry in a broad band along the lower jaw extending from the region of the condyle to the chin than Group 2. The mean facial asymmetry (1 s.d.) for each JIA group was 2.3 (0.9), 2.0 (0.7), 1.7 (0.5) mm for Groups 1, 2 and 3, respectively. Conclusion. JIA subjects with TMJ involvement displayed patterns of facial asymmetry consistent with the destruction of the condylar growth centre, leading to mandibular asymmetry with displacement of the bony chin. Facial asymmetry quantification was found to be an effective method for assessing both the amount and the localization and spatial extent of asymmetry in all 3Ds.