The Molecular and Cellular Events That Take Place during Craniofacial Distraction Osteogenesis

Summary: Gradual bone lengthening using distraction osteogenesis principles is the gold standard for the treatment of hypoplastic facial bones. However, the long treatment time is a major disadvantage of the lengthening procedures. The aim of this study is to review the current literature and summarize the cellular and molecular events occurring during membranous craniofacial distraction osteogenesis. Mechanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biological processes that may include differentiation of pluripotential tissue, angiogenesis, osteogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Studies have implicated number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (transforming growth factor-β, bone morphogenetic proteins, insulin-like growth factor-1, and fibroblast growth factor-2) and extracellular matrix proteins (osteonectin, osteopontin) during distraction osteogenesis has been best characterized and discussed. Understanding the biomolecular mechanisms that mediate membranous distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone regeneration that may lead to shorten the treatment duration

Management of Severely Atrophic Maxilla in Ectrodactyly Ectodermal Dysplasia-cleft Syndrome

Background:. Ectrodactyly ectodermal dysplasia-cleft syndrome is a rare genetic syndrome with an incidence of 1/90,000 live births, characterized by cleft lip and palate, severely hypoplastic maxilla, and hypodontia. Patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome suffer from a severely hypoplastic maxilla that is highly difficult to treat using traditional orthognathic methods. In this study, we propose using distraction osteogenesis to achieve a major advancement while maintaining good stability and minimal relapse. To our knowledge, this is the first description of patients with this syndrome treated using distraction osteogenesis. Methods:. Five patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome were included in the study. All patients had been operated on according to the well-established protocol of cleft lip and palate reconstruction before maxillary distraction osteogenesis. Hard and soft-tissue changes were evaluated by cone beam computed tomography and lateral cephalograms before distraction osteogenesis (T1), at the postdistraction point (T2) and after 1 year of follow-up (T3). Results:. Examination revealed marked maxillary advancement in all our patients with a significant mean difference in hard tissue parameters (condylion to A point = 18 mm; nasion-sella line to A point = 15.2 degrees) and a notable improvement in facial convexity (20.9 degrees). One year follow-up measurements demonstrated mild relapse rates of 6% in the horizontal plane. Conclusions:. We conclude that despite the challenging anatomic and physiological features of ectrodactyly ectodermal dysplasia-cleft patients, by enhancing current surgical techniques, there is promising potential for improved patient outcomes, achieving normognathic facial appearance with implant supported rehabilitation

External versus Internal Distraction Devices in Treatment of Obstructive Sleep Apnea in Craniofacial Anomalies

Background: Obstructive sleep apnea is often associated with congenital craniofacial malformations due to hypoplastic mandible and decreased pharyngeal airway. In this study, we will compare external and internal distraction devices for mandibular lengthening in terms of effectiveness, results, patient comfort, and complications. Methods: Thirty-seven patients were treated by bilateral mandibular distraction osteogenesis for obstructive sleep apnea: 20 with external and 17 with internal distraction devices. Results: Lengthening of the mandible and increase of the pharyngeal airway were obtained in all patients. Using the external devices, the average mandibular elongation was 30 mm versus 22 mm with the internal devices; however, after 1 year, the results were more stable with internal devices. External devices carried greater risk for pin tract infection than the internal devices (27.5% vs 5.88%). In addition, pin loosening in 22.5% required pin replacement or led to reduced retention period. Internal devices had a precise and predictable vector of lengthening and left less visible scars at the submandibular area but carried the disadvantage of requiring a second operation for device removal. In very young children with severe micrognathia, it was impossible to place internal devices, and external devices were used. Conclusions: Internal devices should be the first choice because they are more comfortable to the patients, more predictable vector of lengthening, are less vulnerable to dislodgement, and leave reduced scarring, with the great disadvantage of second operation for removal. However, external devices still should be considered mainly in severely hypoplastic cases, and the surgeon should be prepared for both options

Cleft Palate Fistula Closure Utilizing Acellular Dermal Matrix

Summary:. Fistulas represent failure of cleft palate repair. Secondary and tertiary fistula repair is challenging, with high recurrence rates. In the present retrospective study, we review the efficacy of using acellular dermal matrix as an interposition layer for cleft palate fistula closure in 20 consecutive patients between 2013 and 2016. Complete fistula closure was obtained in 16 patients; 1 patient had asymptomatic recurrent fistula; 2 patients had partial closure with reduction of fistula size and minimal nasal regurgitation; 1 patient developed a recurrent fistula without changes in symptoms (success rate of 85%). We conclude that utilizing acellular dermal matrix for cleft palate fistula repair is safe and simple with a high success rate