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This study examined the potential for dental magnets to act as a driving force for osteogenesis in the palate of newborns with a unilateral cleft lip and palate. In the first part of the study dental magnets were arranged in a set up mimicking a distraction device and the curves of the magnetic attraction force versus gap distance curves generated, with and without the presence of palatal rugae tissue in between both sides of the distraction device. The attraction forces ranged from 1 to 12 N depending on the gap distance and the presence of soft tissue in the gap. In the second part of the study these forces were used as input for a 3D finite element model of the palate of a newborn affected by unilateral cleft lip and palate. In the analysis of load transfer, it was found that the strains generated by a magnetically induced distraction exceed 1,500 µstrain suggesting that bone locally is submitted to mild overload leading to bone apposition.

Objectives: To assess the impact of cleft severity and timing of hard palate repair on palatal dimensions in unilateral cleft lip and palate (UCLP) children., Setting and Sample Population: Single-centre analysis within a multicenter RCT of primary surgery; 122 UCLP randomized to early hard palate closure (EHPC) at 12 months or delayed hard palate closure (DHPC) at 36 months; 28 frequency-matched controls., Methods: Linear measurements of palatal height, width and length were performed on 116 digital models of UCLP subjects (8.21 years, SD = 0.53) and 28 models of non-cleft individuals (8.44 years SD = 0.72). Cleft dimensions at infancy (mean 1.8 months) were considered. In a pilot study, shell-to-shell distances between the 3D cleft palate objects and a reference mesh were calculated and differences between the groups assessed. Morphological differences were visualized using colour mapping., Results: Compared to controls, UCLP subjects presented a higher palate at the level of the anterior scar (P = 0.002), but generally a lower palate in the middle region (P < 0.001). Comparing UCLP subgroups, the DHPC subjects showed a flatter palate posteriorly (P = 0.048) and the EHPC group exhibited more transversal constriction (P = 0.003 at M1 level). 3D analysis revealed a shallower palate in the DHPC group both in the middle (P = 0.002) and the posterior part (P = 0.008). Anterior cleft severity correlated negatively with palatal height (P = 0.01)., Conclusions: Unilateral cleft lip and palate palates differ from controls in width and height. DHPC may represent an advantage for the transversal dimension, but a disadvantage for palatal height. Infant cleft dimensions partially explain differences in palatal height., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The primary correction of congenital complete unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) is challenging due to inherent lack of palatal tissue and small extent of the palatal shelves at birth. The tissue deficiency affects the nasal mucosa, maxillary bone and palatal mucosa. This condition has driven the evolution of several surgical and non-surgical techniques for mitigating the inherent problem of anatomical deficits. These techniques share the common principle of altering the neighboring tissues around the defect area in order to form a functional seal between the oral and nasal cavity. However, there is currently no option for rectifying the tissue deficiency itself. Investigations have repeatedly shown that despite the structural tissue deficiency of the cleft, craniofacial growth proceeds normal if the clefts remain untreated, but the cleft remains wide. Conversely, craniofacial growth is reduced after surgical repair and the related alteration of the tissues. Therefore, numerous attempts have been made to change the surgical technique and timing so as to reduce the effects of surgical repairs on craniofacial growth, but they have been only minimally effective so far. We have determined whether the intrinsic structural soft and hard tissue deficiency can be ameliorated before surgical repair using the principles of periosteal distraction by means of magnetic traction. Two three-dimensional maxillary finite element models, with cleft patterns of UCLP and BCLP, respectively, were created from computed tomography slice data using dedicated image analysis software. A virtual dental magnet was positioned on either side of the cleft at the mucoperiosteal borders, and an incremental magnetic attraction force of up to 5 N was applied to simulate periosteal distraction. The stresses and strains in the periosteal tissue induced by the magnet were calculated using finite element analysis. For a 1 N attraction force the maximum strains did not exceed 1500 µstrain suggesting that adaptive remodeling will not take place for attraction forces lower than 1 N. At 5 N the regions subject to remodeling differed between the UCLP and BCLP models. Stresses and strains at the periosteum of the palatal shelf ridges in the absence of compressive forces at the alveolar borders were greater in the UCLP model than the BCLP model. The findings suggest that in newborns with UCLP and BCLP, periosteal distraction by means of a magnetic 5 N attraction force can promote the generation of soft and hard tissues along the cleft edges and rectify the tissue deficiency associated with the malformation. [ABSTRACT FROM AUTHOR]

The aim of this cohort study was to quantify the morphological changes in the palatal cleft and true cleft areas with passive plate therapy using a new analysis method based on three-dimensional standardized reproducible landmarks. Forty-five casts of 15 consecutive patients with complete unilateral cleft lip and palate were laser scanned and investigated retrospectively. The landmarks and the coordinate system were defined, and the interrater and intrarater measurement errors were within 1.0 mm. The morphological changes of the cleft palate area after a period of 8 months of passive plate therapy without prior lip surgery are presented graphically. The median decrease in cleft width was 38.0% for the palatal cleft, whereas it was 44.5% for the true cleft. The width of the true and palatal cleft decreased significantly over a period of 8 months. The true cleft area decreased by 34.7% from a median of 185.4 mm2 (interquartile range, IQR = 151.5–220.1) to 121.1 mm2 (IQR = 100.2–144.6). The palatal cleft area decreased by 31.5% from a median of 334 mm2 (IQR = 294.9–349.8) to 228.8 mm2. The most important clinical considerations are the reproducibility and reliability of the anatomical points, as well as the associated morphological changes. We propose using the vomer edge to establish a validated measuring method for the width, area, and height of the true cleft. [ABSTRACT FROM AUTHOR]