Microvascular free flaps (MFFs) represent the gold standard for reconstructing warrelated injuries in the head and neck within Oral and Maxillofacial Surgery (OMFS). Specifically, in bony reconstructions of the midface or mandible using fibula or iliac crest free flaps, the advent of digital planning and the intraoperative use of 3D-printed, patient-specific surgical guides have transformed surgical practices. These guides, which can be digitally designed and produced in-house via additive manufacturing (AM), facilitate reduced surgery times and enhance surgical precision, offering significant benefits for both surgeons and patients. However, the intraoperative application of in-house 3D-printed devices is increasingly regulated, posing challenges for compliance within the European Union. This study aimed to gather specific data on the implementation of 3D printing and in-house AM in OMFS across Germany, with the goal of developing tailored recommendations for effective in-house 3D printing practices. An online questionnaire, featuring dynamic components and consisting of 16 to 29 questions, was distributed to OMF surgeons in university and non-university hospitals, military medical facilities, and private practices, both those with and without inpatient treatment capabilities. Participants were recruited from a previous study on 3D printing, ensuring that all respondents owned a 3D printer and were registered with the German Association of Oral and Maxillofacial Surgery. The study collected responses from 67 participants after an initial recruitment yielded only 5 out of 92. Participants were from university hospitals, non-university hospitals, and private practices. Among them, 75% of university hospitals owned 3D printers. Most frequently, participants performed dental implant procedures, using between 20 to 100 CAM products annually. In traumatology, many conducted over 150 procedures but used few CAM products. For orthognathic surgery, 50-100 procedures were common, often with corresponding CAM product usage. Participants employed various 3D printing technologies, primarily SLA and FLDM, with autoclaving as the main sterilization method. Many reported no immediate impact from new Medical Device Regulations (MDR) but indicated plans for future adaptations. Most 3D data were generated from radiologic sources, using a mix of certified and non-certified CAD software. Quality assurance measures were conducted in 65% of units, though standardized operating procedures (SOPs) were largely absent. Quality control processes varied, with some participants performing regular checks and documenting results. Most focused on verifying the fit and integrity of printed goods during surgery. CAD data were mostly archived centrally, with segmentation and CAD processes primarily carried out by medical doctors. Over half of participants found owning a 3D printer economically beneficial, rating its financial impact positively, though many did not conduct formal evaluations.The findings reveal considerable disparities in 3D printing management within OMFS, particularly regarding workflow processes, quality control, and documentation. Given the increasing regulatory demands for medical devices, there is an urgent need for standardized recommendations and regulations for 3D printing in OMFS, especially in the context of reconstructing war-related injuries. Key recommendations include: (1) ensuring products are not used in other facilities, (2) implementing appropriate quality systems, (3) documenting reasons for bypassing commercial products, (4) providing information about usage to the relevant authorities, (5) maintaining a publicly accessible declaration of origin, identification, and conformity with MDR, (6) keeping records of manufacturing sites, processes, and performance data, (7) ensuring all products are produced according to predefined requirements, and (8) evaluating clinical use and addressing potential issues. These measures are crucial for ensuring patient safety and maintaining the viability of in-house 3D printing in OMFS.