Dends are tempermental, they loose a few leaves from the bottom up periodically, which is the norm. If you have a larger area of leaf loss than its important to see if the cause could be pest related. Dends. will loose lower leaves and leave a long stalk so to speak as they go into adulthood, new shoots should appear around the bottom areas of the plant.
Do you have any
![Photo](http://www.orchidboard.com/community/images/smilies/new/photo.gif)
's of your dend, it would be of help, also go to the thread "baffled" under dend and see if yours looks like Sue's.