# A Prospective, International, Multicentre Registry of Patients Undergoing Segmental Mandibular Defect Reconstruction After Mandibular Resection for Tumours and Drug-Induced Osteonecrosis: A Study Protocol

## TL;DR

This study aims to collect real-world data on jawbone reconstruction surgeries for cancer and drug-related bone damage through an international patient registry.

## Contribution

The novel contribution is establishing an international multicenter registry to systematically track outcomes of mandibular reconstruction for rare and drug-induced conditions.

## Key findings

- The registry will prospectively follow ~300 patients over 36 months.
- It will document treatment outcomes and adverse events for various mandibular reconstruction approaches.
- The study will identify predictors of successful autologous reconstruction.

## Abstract

Segmental mandibular resection may be indicated as a treatment in, for example, advanced stages of oral squamous cell carcinoma (OSCC). Osseous reconstruction of these defects is a fundamental part of static and dynamic masticatory rehabilitation, particularly when dental implants are required. The Segmental Mandibular Defect Reconstruction (SMDR) Registry aims to generate real-world evidence on SMDR through an international, prospective, multicentre case series designed as a registry. While OSCC is a common indication for segmental mandibular resection, the SMDR Registry also aims to capture outcomes for rarer mandibular conditions and the increasing number of collateral damage cases resulting from systemic medication therapies (antiresorptive drugs, immunotherapeutics) or irradiation, which may likewise lead to medication-related osteonecrosis of the mandible (MRONJ) or osteo(radio)necrosis with tumour-like segmental resection of the mandible, highlighting the value of an international database for these less frequent pathologies. Primary objectives are to describe the patient population and current treatment modalities, describe the outcomes and adverse events (AEs) for different treatment modalities, and identify potential predictors for successful autologous reconstruction of SMDs. Approximately 300 patients with a mandibular lesion resulting from bisphosphonate- and immunomodulatory drug-induced osteonecrosis of the mandible, ameloblastoma or osteosarcoma of the mandible, oral metastases related mandibular lesions indicated for segmental resection, or OSCC undergoing SMDR or intending to undergo one- or two-stage reconstruction will be prospectively recruited over a 36-month period. Baseline information, treatment details, and outcome measures will be documented. All treatments will be per the usual practice at participating sites. Outcome measures include clinical, patient-reported, and radiological outcomes; AEs related to the condition and/or treatment with a possible influence on the outcome will be recorded.