Periodontal plastic surgery is widely used to improve the esthetic and functional demands of patients. The palatal masticatory mucosa is the main donor area. A lot of methods to evaluate the thickness of palatal soft tissue were used. However, the methods published before were invasive or non-reproducible. Therefore, the aim of this study was to investigate the accuracy of the novel invasive method to evaluate the thickness of palatal masticatory mucosa thickness.

Twelve periodontally healthy patients who will have CBCT on maxilla for implant surgery will be recruited in this study. Each patient will be measured at 15 points of palatal masticatory mucosa over canine to the second molar area, it will be done by a dynamic navigation system (test group) and periodontal probe piercing (control group). The data will be analyzed to evaluate the accuracy of dynamic navigation in the measurement of palatal masticatory mucosa thickness.

Inclusion criteria:

1. Above 20 years old
2. The patient need dental implant surgery in maxilla
3. The patient have at least complete canine to second molar at one side
4. Periodontaliy healthy patients
5. The patient could sign for the consent form.

Exclusion criteria:

1. patients can not receive dental implant surgery
2. fuzzy palatal alveolar bone line
3. all maxillary posterior teeth with metal crowns
4. all posterior teeth are missing at one side over maxilla
5. all maxillary posterior teeth with hyper-mobility
6. Pregnancy