This looks like a Japanese holly, Ilex crenata. We have had drought symptoms for the past few years, and that can stress the plant, which can cause diseases to be introduced. Also, if the soil isn't well-draining or not acidic enough, that can also cause stress. They may have contracted Thielaviopsis or Botryosphaeria dieback. 

When plants have been pruned/sheared on just the outer branch tips, it can cause thick outer growth that blocks sunlight to the interior of the plant, and the plant cannot grow leaves on the inner branches. It is also creating many little wounds on the plant that can open it up to disease. You can try pruning out the dead or dying branches and ease up on shearing the outside of the plant. If you need to shear to control the size, then afterwards you can remove some inner branches to open up the plant and let light in. However, with this amount of dieback, we are not sure if the plant will be able to grow back in those areas. It also may, but it could take some time, so if you are not willing to wait, you may want to consider replacing them. If you decide to prune the branches and wait to see if new growth emerges, be sure to monitor for watering needs as we move into summer. Much of Maryland is still in a drought now, from last summer. 

It looks like there is a boxwood in the corner of one of the photos, and it has something called psyllids, small insects that feed on the leaves, which is the white coating that looks like fluffy snow on the branches. They are mostly cosmetic issues, but if you notice a heavy infestation, you can follow the management guidance on the link provided. 

Let us know if we can help further. 

Emily