Smart implants for mucoperiosteal tissue expansion in cleft palate defects

Cleft lip and palate are the most common craniofacial malformations, affecting one in every 500 to 700 live births, thus accounting for about 220,000 new cases each year worldwide with tremendous variations across geographic areas, ethnic groups and socioeconomic status. Affected children have a range of both functional and aesthetic problems comprising of feeding difficulties due to incomplete oral seal, swallowing, nasal regurgitation, respiratory problems, hearing difficulties due to abnormalities in the palatal musculature, and speech impairments due to air escape and articulations problems. The surgery can solve the problems, but the two major factors which determine a good surgical outcome and its assessment are the interpretation of the actual size of the cleft and generation of periosteal tissue to close the defect. The surgeons faced a challenge to measure the cleft size due to wide diversity in methodologies employed which resulted in improper estimation of the deficient palatal tissue and thus resulted contradictory results in measuring outcomes such as occlusion or midface skeletal development. We have introduced the vomer edge for establishing a validated 3D measuring method for the width, area and height of the true cleft with reproducible landmarks for easy and accurate measurement of the outcomes in unilateral cleft lip and palate patients. The passive plate therapy provided to UCLP patients gave favourable anatomical conditions for subsequent surgical palatal repair in patients by alleviating the problems of tissue deficiency to some extent. We therefore adopted periosteal tissue distraction osteogenesis as potential treatment strategy to target the tissue deficiency while using the magnetic forces to exert necessary strain. In our study, we have assessed whether the dental magnets have the potential to act as a device to generate mucoperiosteal tissue in UCLP. We have used in-silica approach in the form of 3D FE-model and found that strain levels in the palatal segments of the cleft for the load cases do reach 1500 µstrain limit, a requirement for bone formation, according to the mild overload window of the Mechanostat theory proposed by Harold Frost. We further examined the forces, which reach threshold for regeneration of the hard and soft tissue volumes along the cleft edges in both UCLP and BCLP by means of periosteal distraction. We found that a 5N attraction force could initiate generation of soft and hard tissues along the cleft edges in in-silico model within the optimal biological limits.