Accuracy of Implant Placement for Patients With Mandibular Reconstruction Using Dynamic Navigation and Static Guides

• The guidance of dynamic navigation (Procedure): Osteotomy and implant placement with the guidance of dynamic navigation
• The guidance of static template (Procedure): Osteotomy and implant placement with the guidance of static template

Primary outcomes

• Three-dimensional implant placement accuracy of apical point [Postoperative day 2±1]: The postoperative cone beam computed tomography (CBCT) was aligned to the preoperative plan in specific software, and the three-dimensional coordinates of the preoperatively planned and actual postoperative implant placement positions were measured separately, from which the three-dimensional distance (in mm) between the apical point of the actual implant and the apical point of the virtual implant was calculated.

Secondary outcomes

• Three-dimensional implant placement accuracy of coronal point [Postoperative day 2±1]: The postoperative CBCT was aligned to the preoperative plan in specific software, and the three-dimensional coordinates of the preoperatively planned and actual postoperative implant placement positions were measured separately, from which the three-dimensional distance (in mm) between the coronal point of the actual implant and the coronal point of the virtual implant was calculated.
• Three-dimensional implant placement angular accuracy [Postoperative day 2±1]: The postoperative CBCT was aligned to the preoperative implant placement plan in specific software to measure the three-dimensional coordinates of the preoperative plan and the actual postoperative implant placement position, respectively, and to calculate the angle (°) between the actual implant and the mid-axis of the virtual implant accordingly.
• Operation time [Intraoperative]: From the beginning of anesthesia to the complete removal of the static template or navigation reference frame.
• Patient subjective satisfaction [Postoperative day 14±1]: Evaluating patient satisfaction with the visual analogue scale
• Failure rate during implant healing period [Postoperative day 90±7]: 1\. According to the definition of Albrektsson and Zarb in 1986, the healing period is considered successful if the following conditions are met: no loosening of the implant after removal of the upper restoration; no peri-implant radiolucency; no peri-implant bone instability; and no pain. Implant retention was evaluated according to three levels: good osseointegration, poor osseointegration, and implant failure. 2. Implant survival rate = (N total - N failure)/(N total) × 100%.

Sex: All, ages: 18 Years to 70 Years, accepts healthy volunteers

Inclusion Criteria:

* Male or female patients between the ages of 18 and 70 (inclusive)
* Mandibular defects (including Class I defects, limited to the body of the mandible; Class II defects, muscular-mandibular region defects and Class III defects, chin protrusion-muscular-mandibular region defects), which have been reconstructed by mandibular vascularization of free iliac bone, and fibular composite muscular flap grafts for greater than 3 months
* Normal mouth opening (≥ 40 mm)
* Trialists voluntarily signed an informed consent form before performing any research-related experimental steps.

Exclusion Criteria:

* Presence of localized inflammation in adjacent teeth, including uncontrolled periodontitis (periodontal probing to a depth of >4 mm)
* Presence of untreated acute and chronic apical periodontitis in adjacent teeth
* Oral mucosal lesions (e.g., lichen planus)
* Adjacent teeth with space-occupying lesions (including cysts, tumors, etc.)
* Systemic diseases affecting bone healing, wound healing and dental implant treatment (e.g., uncontrolled diabetes mellitus, fasting blood glucose ≥ 8.8 mmol/L despite medication)
* Uncontrolled and unstabilized severe hypertension
* Contraindications to routine implant surgery and oral surgery
* Heart disease (Class II or above)
* Patients with liver or kidney insufficiency or abnormality
* Obese patients with body mass index (BMI) > 28 kg/m2
* Patients with a history of full-dose radiotherapy, localized radiotherapy to the head or neck
* Patients requiring long-term high-dose steroid therapy
* Patients who are receiving or have received in the last 3 months medications (e.g., bisphosphonates) that may affect or promote bone metabolism
* Consecutive antibiotic therapy or chronic anti-inflammatory therapy (≥3 times per week) within the first 4 weeks of starting the procedure
* Alcohol or chronic substance abuse
* Immunocompromised patients
* Smoking/tobacco equivalents/chewing tobacco >10 cigarettes per day
* Physical or mental impairment that interferes with the performance of oral hygiene care
* Female patients who are pregnant or breastfeeding
* Patients who, in the opinion of the investigator, have poor compliance and cannot participate in the trial
* Patients who have participated in a clinical trial of another drug or device within 30 days prior to the start of the procedure (Study Day 0)