Is a dental "occlusal guard" (to wear at night time) the same as a dental "nightguard"?

Depends: While they can go by several differnent names all nightguards, occlusal guards, bruxism appliances, occlusal splints are not the same. The best ones are custom fit to your teeth and TMJ and are made by dentists with training in TMJ and occlusion. Many are just made over your teeth and while the goal is to protect teeth from wear while grinding, they don"t alway accompllish this.

Maybe: Many times the terms are used interchangeably. There are times when a occlusal guard is made to treat jaw problems, tmd, headaches and neck and shoulder aches. They are more complicated, cost more, and are more beneficial . They can't be purchased over the counter. They are made for your specific problem and have a custom fit.