Registry to Collect Data on Patients Undergoing Segmental Mandibular Defect Reconstruction Following Oral Squamous Cell Carcinoma Resection and Drugs-induced Osteonecrosis

Inclusion Criteria:

* The study includes patients with an initial pathological/histologic diagnosis of mandibular involvement by oral tumors (such as OSCC, osteosarcoma, and ameloblastoma), bisphosphonate- or immunomodulatory drug-induced osteonecrosis, and mandibular lesions from metastatic conditions originating from other sites including lung, breast, prostate, or kidney.
* Age 18 years and older
* Bisphosphonate related osteonecrosis of the mandible
* Immunomodulatory drugs induced mandibular osteonecrosis
* Patients presented with ameloblastoma affecting the mandible
* Patients presented with osteosarcomas of the mandible
* Patients presented with oral metastases related mandibular lesions that are indicated for segmental resection, common primary tumor sites include lung, breast, prostate and kidney
* Undergoing primary curative treatment with segmental resection of the mandible ≥2 cm
* Intention to undergo mandibular reconstruction with autologous bone using a primary (one-stage) or secondary (two-stage) approach
* Informed consent obtained, ie:

  * Ability to understand the content of the patient information/ICF
  * Willingness and ability to participate in the clinical investigation according to the registry plan (RP) o Signed and dated IRB/EC approved ICF OR
  * Written consent provided according to the IRB/EC defined and approved procedures for patients who are not able to provide to provide independent written informed consent

Exclusion Criteria:

* Tumors affecting the condyle
* Patients under palliative care
* Previous extensive mandibular surgeries (including reconstructions, e.g., TMJ replacement) that may potentially confound the outcome measures

Intraoperative exclusion criteria:

* Nonsegmental mandibular defect (eg. box resection/partial resection)
* Segmental mandibular defect of less than 2 cm
* Mandibular defects extending beyond the sigmoid notch into the condyles

Additional exclusion criterion:

• No osseous reconstruction with autologous bone performed within 18 months from resection