It is the key step of the occlusal reconstruction to determine the correct occlusal vertical dimension for edentulous patients. Although there are several methods in clinical practice, there is no ideal way. This paper summarizes the following methods: inter-occlusal distance, closest speaking space method, pre-extraction record, face proportion division method and facial appearance observation, cephalometric analysis, electromyography, swallowing, bite force determination and self feeling method. In this paper, the current research status and the feasibility of each method are discussed.

Unilateral maxillary defects are common clinical maxillofacial deformities. Because of their large area and the complexity of the maxillary structure, the distribution of pressure from dental prostheses and on the sustentacular tissue is usually uneven, which often results in pain or ulceration of the soft tissue and agomphiasis during the therapeutic process. Recently, the finite element method has been used to guide prosthesis design and implantation. This method is conducive to the restoration and stability of the dental prosthesis and the protection of the remaining tissue, which improves restoration quality and patient satisfaction. This paper summarizes the establishment of a three-dimensional finite element model of unilateral maxillary defects and its application in repairing unilateral maxillary defects with traditional prostheses, implant-supported prostheses and surgical flap transplantation combined with prostheses.

The concept of“minimally invasive dentistry”aims to provide conservative treatment of cavities in which sound dentin is removed. Because the Er: YAG laser can selectively remove caries, the smear layer is removed, dentin tubules are exposed after the preparation of substrate conditioning, and its advantages of precision, safety and painlessness are deeply valued. At the same time, the bonding strength between the prepared dentin surface and the filling material is different due to the different parameters of the Er: YAG laser. In this paper, the principle of dentin bonding, the mechanism of Er: YAG laser action, after treatment of dentin with different parameters (power, energy density, pulse duration, and irradiation distance), whether there is thermal damage to pulp tissue, the ultramicro morphology of dentin surface, the bonding properties of different bonding systems and the filling materials between irradiated hard tissues were reviewed. An appropriate parameter range (power ≤ 10 Hz, energy density ≤ 60 mJ, and pulse duration ≤ 50 μs) combined with water spray cooling will not cause thermal damage to the pulp tissue, while the higher power, energy density and pulse duration of laser treatment for dentin will lead to melting, carbonization, cracks, narrowing of the gap between collagen fibers, etc., which will limit the penetration of adhesives and have a negative impact on bonding. However, whether the adhesive systems based on the smear layer are suitable for dentin after laser treatment needs to be further explored.