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Following a decompressive craniectomy, the autologous bone flap is generally considered the reconstructive material of choice in pediatric patients. Replacement of the original bone flap takes advantage of its natural biocompatibility and the associated low risk of rejection, as well as the potential to reintegrate with the adjacent bone and subsequently grow with the patient. However, despite these advantages and unlike adult patients, the replaced calvarial bone is more likely to undergo delayed bone resorption in pediatric patients, ultimately requiring revision surgery. In this review, we describe the materials that are currently available for pediatric cranioplasty, the advantages and disadvantages of autologous calvarial replacement, the incidence and classification of bone resorption, and the clinical risk factors for bone flap resorption that have been identified to date.

Osteomas are benign bony lesions that can occur throughout the craniofacial skeleton. Surgical excision can be an effective treatment, as recurrence is relatively uncommon. Outside of incomplete resection, causes of recurrence are poorly documented, especially in the pediatric population. Exchange cranioplasty is an autologous reconstructive surgical option for patients of all ages, and it can be effective in the treatment of large calvarial osteomas. Recurrent lesions of the cranioplasty site have not been well described in the literature, with only 3 documented reports. In this study, we present a unique case of a recurrent osteoma at the site of a prior exchange cranioplasty. The authors also provide a systematic review of the literature for recurrent osteomas and highlight causes and conclusions for these lesions. Utilizing the PRISMA guidelines, a systematic review of articles published across databases was performed to identify accounts of recurrent osteomas at prior cranioplasty sites. Our systematic review illustrates that recurrent osteomas overlying different cranioplasty biomaterials is a rare entity and is due to incomplete resection of the galea and periosteum during the index procedure. Biomaterial selection for the pediatric population requires careful consideration before reconstruction. Though limited by 3 articles previously published and without a direct link to recurrence, long-term studies are needed to further guide biomaterial selection in the pediatric population to evaluate potential recurrences.

The airline industry closely monitors the midlatitude jet stream for short-term planning of flight paths and arrival times. In addition to passenger safety and on-time metrics, this is due to the acute sensitivity of airline profits to fuel cost. US carriers spent US$47 billion on jet fuel in 2011, compared with a total industry operating revenue of US$192 billion. Beyond the timescale of synoptic weather, the El Niño/Southern Oscillation (ENSO), Arctic Oscillation (AO) and other modes of variability modulate the strength and position of the Aleutian low and Pacific high on interannual timescales, which influence the tendency of the exit region of the midlatitude Pacific jet stream to extend, retract and meander poleward and equatorward. The impact of global aviation on climate change has been studied for decades owing to the radiative forcing of emitted greenhouse gases, contrails and other effects. The impact of climate variability on air travel, however, has only recently come into focus, primarily in terms of turbulence. Shifting attention to flight durations, here we show that 88% of the interannual variance in domestic flight times between Hawaii and the continental US is explained by a linear combination of ENSO and the AO. Further, we extend our analysis to CMIP5 model projections to explore potential feedbacks between anthropogenic climate change and air travel.

When a shortwave trough moves eastward over the Rocky Mountains and into the central United States, the following important features may form: a drytrough (i.e., a lee trough that also has the characteristics of a dryline), an arctic front, a low-level jet, and two synoptic-scale rainbands (called the cold front aloft rainband and the pre-drytrough rainband) that can produce heavy precipitation and severe weather well ahead of the drytrough. These features are incorporated into a new conceptual model for cyclones in the central United States. Use of this model can aid the interpretation of observational data and numerical model output, and it may also help to improve short-range forecasting in the central United States.

A feature‐based metric of the waviness of the wintertime, Northern Hemisphere polar, and subtropical jets is developed and applied to three different reanalysis data sets. The analysis first identifies a “core isertel” along which the circulation per unit length is maximized in the separate polar (315:330K) and subtropical (340:355K) jet isentropic layers. Since the core isertel is, by design, an analytical proxy for the respective jet cores, the waviness of each jet is derived by calculating a hemispheric average of the meridional displacements of the core isertel from its equivalent latitude—the southern extent of a polar cap whose area is equal to the area enclosed by the core isertel. Analysis of the seasonal average waviness over the time series of the various data sets reveals that both jets have become systematically wavier while exhibiting no trends in their average speeds. The waviness of each jet evolves fairly independently of the other in most cold seasons and the slow northward creep of the polar jet is statistically significant. Finally, comparison of the composites of the waviest and least wavy seasons for each species reveals that such interannual variability is manifest in familiar large‐scale circulation anomalies. Among the most common structural features of the earth's atmosphere are the narrow, meandering ribbons of maximum wind speed known as the jet streams. On any given winter day, there are usually two such jet streams; one located at ∼9 km (the polar jet) and another, further south, located at ∼12 km (the subtropical jet). These jet streams are both important weather producing features as well as influential governors of regional climate. This study considers trends in the wintertime waviness of the two jets as portrayed in three different data sets with long time series. The analysis reveals three important results. First, the waviness of both jets has been systematically increasing since ∼1960. Second, despite their increasing waviness, the maximum speed of both jets has hardly changed. Third, the polar jet has been creeping slowly, but persistently, poleward over the last several decades. All three of these results are consistent with predictions that have recently been made about the behavior of the jets in a warmer climate and thus offer observational support for these forecasts. The tropopause‐level, polar, and subtropical jet streams are becoming increasingly wavy during Northern Hemisphere winterDespite the increase in waviness, the speed of the jets has remained nearly constantThe polar jet is slowly, but systematically, creeping poleward in accord with climate model projections The tropopause‐level, polar, and subtropical jet streams are becoming increasingly wavy during Northern Hemisphere winter Despite the increase in waviness, the speed of the jets has remained nearly constant The polar jet is slowly, but systematically, creeping poleward in accord with climate model projections

Complaints related to the neck are common following mild pediatric trauma. While significant cervical spine injuries are most often seen and evaluated in the emergency room or inpatient setting, the primary care provider is faced with the evaluation of lower acuity complaints. We provide a review to assist with the efficient evaluation of these patients in order to facilitate decisions regarding return to play, the need for imaging, and need for referral to subspecialty providers.

Several letters to the editor are presented in response to articles in previous issues including the "Publisher's View," in the January 15, 2008 issue, "Daily Report" in the Jan 16-17, 2008 issue, and "Publishers View," in the January 15, 2008 issue.

Intracranial insertion of a nasopharyngeal airway is an unusual and catastrophic complication of airway management in the patient with a severe closed head injury. We present an unfortunate 43-year-old patient with intracranial insertion of a nasopharyngeal airway during trauma resuscitation. The nasopharyngeal airway was removed. Attempts to resuscitate the patient were continued, but were eventually unsuccessful. Blind nasopharyngeal airway insertion may result in iatrogenic injury when used in the head-injured patient. Oropharyngeal airways may be used to assist with ventilation. However, it is preferable to definitively secure the airway through inline endotracheal intubation or with surgical techniques in this patient population. Should violation of the skull base occur, removal is accomplished in the controlled environment of the operating room.