Abstract: In addressing complex bone defects, titanium mesh, as one of the non-absorbable barrier membranes, plays a key role in space maintenance. After surgery, a dense fibrous connective tissue, known as pseudo-periosteum, often forms on the surface of the newly formed bone. This tissue can be categorized into three types based on its thickness. The formation of the pseudo-periosteum is closely associated with the use of titanium mesh, and its formation remains unavoidable even with the use of 3D printing individualized titanium mesh. The factors influencing the formation of the pseudo-periosteum are not yet fully understood, but may be include variables such as micromotion of the titanium mesh and pore size. In clinical applications, the pseudo-periosteum has certain value in soft tissue augmentation and protection of new bone, but some researchers argue that it may occupy bone-forming space, and whether it should be retained remains controversial. Currently, the formation mechanism, anatomical and histological characteristics, clinical value, and retention controversies of the pseudo-periosteum have not been comprehensively and systematically elucidated. This review aims to provide a comprehensive analysis of the formation, histological characteristics, clinical applications, and retention controversies of the pseudo-periosteum under titanium mesh, with the goal of offering guidance and reference for clinical practice.

Key words: Alveolar bone augmentation, Titanium mesh, Pseudo-periosteum, Fibrous connective tissue