The usable prosthetic occlusal height is the space into which the prosthesis will fit, and must be sufficient for all prosthetic elements. The reduction of this space may be congenital (microdontia, imperfect eruption of congenital teeth, etc.) or acquired (erosion, abrasion, hyperplasia of the edentulous alveolar ridge). In the case of the congenital form, the procedure is delicate and requires a special laboratory technique. For the acquired form resulting from tooth erosion, the solution may range from simple ameloplasty to fixed prosthesis, with or without technical depulpation and/or coronal elongation, or even tooth avulsion. When the reduction in HOPU is due to dental abrasion without any reduction in DVO, composite prosthetics is often indicated. In the case of alveolar ridge hyperplasia, surgical treatment of the edentulous ridges can restore sufficient HOPU. If etiological treatment is not possible, the prosthetic solution can be adapted to the existing HOPU by integrating the veneered teeth.