Introduction and importance: Intraosseous anesthesia (IOA), an important technique in dental anesthesia, delivers anesthetic directly into the bone, enhancing patient comfort and minimizing side effects. Despite advantages, several disadvantages are known such as injection discomfort, root damage, mechanical obstructions and needle fractures. This report highlights a rare yet significant complication of focal mandibular osteonecrosis following IOA. Case presentation: A 35-year-old male was referred with interdental septum necrosis between teeth 46 and 47, four months post-IOA. CBCT scan confirmed the septum sequestration and periapical osteolysis extending into the mandibular canal. The patient underwent sequestrectomy and tooth extraction under local anesthesia, successfully relieving him of pain. Clinical discussion: Focal osteonecrosis of the jawbone is possibly caused by factors such as frictional heat, improper pressure during perforation, absence of water cooling, and the use of vasoconstrictor-containing anesthetics, impairing blood flow in the low vascularized bone of the interdental septum. Most osteonecrosis cases so far reported are linked to medication, immunocompromised status or irradiation. Conclusion: Focal mandibular osteonecrosis is a rare complication of intraosseous anesthesia. To our knowledge, this is the first reported case of focal osteonecrosis in the mandible in a healthy patient. There are no previous reports in the literature to show this complication in an otherwise healthy individual. Highlights:

3D printing is an important part of orthognathic surgery by enabling accurate anatomical models for preoperative planning. While Stereolithography (SLA) is widely regarded as the gold standard due to its high precision, recent improvements in Fused Deposition Modeling (FDM) raise the question whether PLA-based dental models can provide comparable dimensional accuracy at a lower cost. This study compares FDM and SLA dental models to evaluate whether FDM represents a clinically viable alternative. STL files derived from maxillary and mandibular intraoral scans (IOS) of 20 patients, yielding 40 dental models, were fabricated using both printing techniques. All models were aligned to the reference STL files and analyzed for dimensional deviations. SLA models demonstrated significantly higher dimensional accuracy than PLA-based FDM models, with lower maximum deviations from the reference STL (1.42 mm vs. 1.84 mm). Both techniques achieved clinically acceptable accuracy for splint fitting, with mean deviations below 0.05 mm. Regarding internal validity, both printers showed high reproducibility, although FDM models exhibited a higher median deviation compared to SLA models (0.0267 mm vs. 0.00145 mm). While SLA remains preferable for high-precision indications, FDM offers a cost-effective alternative for routine clinical use without compromising clinical applicability.