Clenchers and Grinders Are Completely Different Animals
Grinders most likely have airway involvement and clenchers, not necessarily.
Grinders use their front teeth excessively, in contrast, clenchers have heavy back teeth contact and almost no front teeth use.
Grinders get relief with a nightguard. Clenchers, many times nightguards will complicate the problem due to the thickness of the nightguard.
Some schools of thought are to permanently treat the clencher problem through Orthodontic treatment to get front teeth to take some of the back teeths load.
Grinders can have the choice of 1. life time nightguard appliance use OR 2. orthodontic treatment and 3. airway corrections.
Grinders usually have a deep bite (top teeth hide the bottom teeth). Clenchers do not.
Clenchers usually have short upper front teeth. Grinders usually have short lower front teeth.
Grinders usually have flat upper canines and premolars. Clenchers canines and premolars are not necessarily worn. Remember, there is always exceptions.
When all professionals learn about this, more viable treatment options will be developed in a matter of time.
For Grinding, I looking at 2 aspects, is there actual nocturnal grinding or simply excessive everyday wear with the Class II malocclusion.
Nocturnal grinding is usually airway related, maybe a self rescue way to open the airway or could be simply a product of shallow sleep.
For the excessive wear without nocturnal Grinding I do not think airway plays a big part. It could be simply the excessive restriction of the front teeth causing the excessive side shift and wear, i.e. grinding.
For Clenchers, most likely airway does not play a part. The clenching is likely caused by teeth not fitting together perfectly so the patient clenches down to get the teeth to fit perfectly together and incentivized the patient to clench more since the teeth feel better.