Bone remodeling, a combination of bone resorption and formation, requires precise regulation of cellular and molecular signaling to maintain proper bone quality. Whereas osteoblasts deposit and osteoclasts resorb bone matrix, osteocytes both dynamically resorb and replace perilacunar bone matrix. Osteocytes secrete proteases like matrix metalloproteinase-13 (MMP13) to maintain the material quality of bone matrix through perilacunar remodeling (PLR). Deregulated bone remodeling impairs bone quality and can compromise hearing since the auditory transduction mechanism is within bone. Understanding the mechanisms regulating cochlear bone provide unique ways to assess bone quality independent of other aspects that contribute to bone mechanical behavior. Cochlear bone is singular in its regulation of remodeling by expressing high levels of osteoprotegerin. Since cochlear bone expresses a key PLR enzyme, MMP13, we examined whether cochlear bone relies on, or is protected from, osteocyte-mediated PLR to maintain hearing and bone quality using a mouse model lacking MMP13 (MMP13−/−). We investigated the canalicular network, collagen organization, lacunar volume via micro-computed tomography, and dynamic histomorphometry. Despite finding defects in these hallmarks of PLR in MMP13−/− long bones, cochlear bone revealed no differences in these markers, nor hearing loss as measured by auditory brainstem response (ABR) or distortion product oto-acoustic emissions (DPOAE), between wild type and MMP13−/− mice. Dynamic histomorphometry revealed abundant PLR by tibial osteocytes, but near absence in cochlear bone. Cochlear suppression of PLR corresponds to repression of several key PLR genes in the cochlea relative to long bones. These data suggest cochlear bone uniquely maintains bone quality and hearing independent of MMP13-mediated osteocytic PLR. Furthermore, the cochlea employs parallel mechanisms to inhibit remodeling by osteoclasts and osteoblasts, and by osteocytes, to protect hearing. Understanding the cellular and molecular mechanisms that confer site-specific control of bone remodeling have the potential to elucidate new pathways that are deregulated in skeletal disease.

IMPORTANCE The paramedian forehead flap (PMFF) donor site scar is hard to disguise and may be a source of patient dissatisfaction. OBJECTIVE To evaluate the aesthetic outcome of W-plasty vs traditional straight-line (SL) closure techniques of the PMFF donor site.

Purpose of review This review summarizes the paediatric laryngotracheoesophageal cleft (LTEC) literature, with an emphasis on recent trends, evaluation and management, surgical techniques, postoperative care of Type III and IV LTECs, and to propose a revised cleft classification system that more accurately reflects our current understanding of these anomalies. Recent findings There are a number of techniques described to address Type III and IV LTEC, from endoscopic to open approaches with thoracotomy. The surgical approach should be tailored to the length of the cleft and its proximity to important anatomical structures. On the basis of review of the literature, we propose a modified Benjamin-Inglis classification (MBI) with subcategories to address this issue. Postoperative complications are common, namely, tracheoesophageal fistulae and tracheomalacia, which may necessitate subsequent procedures or prolonged tracheostomy dependence. Summary The medical and surgical management of Type III and IV LTEC is challenging with a high rate of morbidity and mortality. The rarity and difficulties in management of these malformations have made large cohort studies difficult, thus generalizable recommendations have been elusive. Experience and patient selection are critical for successful endoscopic repair. Anterior cervical approach, often with complete laryngofissure, appears to be the most common and preferred method for open repairs, though some use a lateral approach. The proposed MBI classification appears to be a useful adjunct to aid in surgical decision-making for deeper LTEC.

4 Laryngoscope, 127:1565-1570, 2017.