Background Epithelioid hemangioendothelioma (EHE) is an especially rare, low-grade malignant vascular tumor that, according to WHO classification, is described as locally aggressive tumor with possible metastasis and makes up 1% of all vascular tumors. EHE is characterized by the accumulation of round, eosinophil-infiltrated endothelium cells; with vacuolation of their cytoplasm; frequent angiocentric inflammation; and myxohyaline stroma. This tumor is usually found in the liver, lungs, and bones and is especially rare in the mouth. Case presentation We present an 18-year-old Caucasian female whose oral cavity lesion had been misdiagnosed as marginal periodontitis. The patient was treated improperly for 2 years until she was referred to a maxillofacial surgeon. The patient complained only about gingival recession in the palatal area of her upper-right-side 13th, 14th, and 15th teeth. The lesion’s clinical appearance was of locally ulcerated painless lesion that affect the underlying bone as seen in X-rays in the palatal side of the right canine and the first and second premolars. Patient underwent surgery for her present defect and reconstruction using allogenic bone transplant. The diagnosis of EHE was based on the bony destruction as seen in x-rays and in the accumulation of tumor cells that were 100% positive to CD31; CD34 and ERG to endothelial markers. During the 31-month follow-up period, the patient exhibited no clinical and radiographic complications. Conclusions With this clinical case, we demonstrate that this rare tumor must be included in differential diagnoses of periodontal pathologies to perform histomorphological examination in a timely manner, which could lead to correct diagnosis and adequate treatment.

Background One of the main tasks of dental implantation is the precise insertion of the implant into the edentulous jaw. The purpose of a study was to determine the accuracy of implants inserted using static implantation guides in different conditions.Methods A search for clinical studies was performed in the PubMed databasis. The implantation procedure had to be performed on humans in vivo by using a static surgical guide. Pre and postsurgical CT scans were compared to evaluate the deviation of implants. A meta-analyses was performed to calculate the mean implant collar, apex, depth and axis deviations. A meta-regression analyses was performed by grouping study subgroups according to the method of surgery, implant insertion, jaw, guide support tissue, and the method of guide fixation.Results 19 studies were included in the meta-analysis. Data on 1872 implants were analyzed. Mean deviation was 1.25 mm (95% CI: 1.00, 1.51) at the implant entry point and 1.52 mm (95% CI: 1.18, 1.86) at the apex. Mean axis deviation was 3.47o (95% CI: 3.01, 3.94). Depth deviation was 0.15 mm (95% CI: -0.36, 0.66). The following factors had a positive influence on the implant precision: open surgical technique, fully guided implant insertion and fixation of the surgical guide.Conclusions The surgical technique, implant insertion method, jaw, guide supporting tissue and fixation has an effect on the deviation of inserted implants.