This goal of this single-blind, simple randomized, positive-controlled prospective study is to evaluate the effects of additive-manufactured personalized titanium mesh and traditional titanium mesh in guided bone regeneration for large alveolar bone defects. The study will assess the short-term and long-term efficacy, safety, and incidence of complications of the additive-manufactured personalized titanium mesh, along with an analysis of risk factors. Participants will be followed up for two years after surgery with free-of-charge clinical and radiographic examinations.

Inclusion Criteria:

1. Patients missing single or multiple teeth with moderate to severe bone defects in the edentulous area requiring complex guided bone regeneration. （Moderate bone defects: bone loss with residual alveolar ridge width between 1 mm and 3 mm; severe bone defects: bone loss with residual alveolar ridge width ≤ 1 mm.）
2. The edge of the edentulous area within 1 mm is alveolar bone, with no adjacent tooth roots or nerve canals, ensuring complete retention of the personalized titanium mesh edge. The apical edge of the edentulous area within 2 mm is alveolar bone, with no nerve canals, ensuring that retention screws for the personalized titanium mesh can be designed in this area.
3. The patient and/or his/her guardian agrees to participate in this trial and signs the informed consent form.

Exclusion Criteria:

1. Patients with edentulism.
2. Patients with mild bone defects (residual alveolar ridge width greater than 3 mm).
3. Presence of acute or chronic infection in the surgical area.
4. Presence of acute or chronic infection in the teeth adjacent to the edentulous area.
5. Participation in similar trials or other interventional clinical trials within 30 days prior to signing the informed consent form.
6. History of metal allergies, severe allergy history, or severe immune deficiency.
7. Uncontrolled metabolic diseases, such as Type 1 diabetes or Type 2 diabetes (HbA1c ≥ 7% or fasting blood glucose ≥ 7 mmol/L despite medication control), severe liver or kidney dysfunction (ALT, AST > 2 times the upper limit of normal, serum creatinine above the upper limit of normal).
8. Long-term use of steroid medications.
9. History of drug abuse or alcoholism.
10. Pregnant or breastfeeding women.
11. Poor compliance.
12. Other conditions deemed unsuitable for participation by the investigator.