Comparison of the accuracy of implant position among freehand implant placement, static and dynamic computer-assisted implant surgery in fully edentulous patients: a non-randomized prospective study.

The optimal implant position is a critical factor for long-term success in fully edentulous patients. Implants can be placed through conventional freehand, static computer-assisted implant surgery (CAIS), or dynamic CAIS protocols, but at present there is very limited clinical evidence on their accuracy in fully edentulous patients. This study was performed to evaluate the accuracy of implant placement using three protocols in fully edentulous patients. Thirteen patients received 60 implants with the freehand (n = 20), static CAIS (n = 20), or dynamic CAIS (n = 20) protocol. Postoperative cone beam computed tomography was utilized to evaluate the accuracy of implant placement in relation to the planned optimal position. The data were analysed by ANCOVA followed by Bonferroni analysis. The mean angular deviation (standard deviation) in the freehand, static CAIS, and dynamic CAIS groups was 10.09° (4.64°), 4.98° (2.16°), and 5.75° (2.09°), respectively. The mean three-dimensional deviation (standard deviation) at the implant platform in the freehand, static CAIS, and dynamic CAIS groups was 3.48 (2.00) mm, 1.40 (0.72) mm, and 1.73 (0.43) mm, while at the implant apex it was 3.60 (2.11) mm, 1.66 (0.61) mm, and 1.86 (0.82) mm, respectively. No difference in terms of accuracy was found between static and dynamic CAIS; both demonstrated significantly higher accuracy when compared to the freehand protocol in fully edentulous patients.

Which characteristics can be expected from p16+-squamous cell carcinomas of the posterior oral cavity and oropharynx? - Distinctive results from Central Germany.

PURPOSE: Human papillomaviruses (HPV) link to a subset of head and neck squamous cell carcinomas (HNSCC). Our aim was to identify clinicopathological characteristics (CPC) of squamous cell carcinomas of the posterior oral cavity and oropharynx (SCCPOCO) associated with HPV p16+. METHODS: Using a retrospective cohort study design, we enrolled a sample of SCCPOCO patients treated in a Central German hospital over a 3-year period. The predictor variables: CPCs, were grouped into demographic, social, anatomic and prognostic. The main outcome variable was p16+. Appropriate statistics were computed, and P≤0.05 was considered statistically significant. RESULTS: Of 199 HNSCC patients, 23 had SCCPOCO and entered the analysis (mean age, 67±12 years; 4 females; 16 in stage I; 4 p16+; 22 underwent primary surgery). We found 8 cervical lymph node metastases (34.8%), 3 distant metastases (13%), 9 recurrences (30.1%) and 3 overall deaths (13%). With the exception of recurrence (P=0.006) and overall death (P=0.02), p16+ was not associated with predictor variables: young age, male gender, smoking, alcohol consumption, tumor location, TNM stages, time to recurrence, metastases, death from disease and survival of smokers (P>0.05). Primary brachytherapy failed to improve survival of p16+-SCCPOCO patients (P=0.04). CONCLUSIONS: The results of this study suggest that p16+- and p16--SCCPOCOs in Central Germany share similar CPCs, except recurrence and overall death. Upfront surgery with/without radio(chemo)therapy is recommended for all operable SCCPOCOs, regardless of HPV-status. Patients with p16+-SCCPOCOs require close follow-up. Future research should investigate the cause of these distinctive CPCs.

Accuracy of implant position when placed using static computer-assisted implant surgical guides manufactured with two different optical scanning techniques: a randomized clinical trial.

Data from cone beam computed tomography (CBCT) and optical scans (intraoral or model scanner) are required for computer-assisted implant surgery (CAIS). This study compared the accuracy of implant position when placed with CAIS guides produced by intraoral and extraoral (model) scanning. Forty-seven patients received 60 single implants by means of CAIS. Each implant was randomly assigned to either the intraoral group (n=30) (Trios Scanner, 3Shape) or extraoral group (n=30), in which stereolithographic surgical guides were manufactured after conventional impression and extraoral scanning of the stone model (D900L Lab Scanner, 3Shape). CBCT and surface scan data were imported into coDiagnostiX software for virtual implant position planning and surgical guide design. Postoperative CBCT scans were obtained. Software was used to compare the deviation between the planned and final positions. Average deviation for the intraoral vs. model scan groups was 2.42°±1.47° vs. 3.23°±2.09° for implant angle, 0.87±0.49mm vs. 1.01±0.56mm for implant platform, and 1.10±0.53mm vs. 1.38±0.68mm for implant apex; there was no statistically significant difference between the groups (P>0.05). CAIS conducted with stereolithographic guides manufactured by means of intraoral or extraoral scans appears to result in equal accuracy of implant positioning.

Clinical approach to rhizomicry based on a case of dentine dysplasia type 1.

Differential diagnosis of generalised rhizomicry (root dwarfism) includes many diseases and syndromes. When the patient has normal stature with no evidence of ghost teeth, no systematic diseases and no history of irradiation or chemotherapy, the dental features are pathognomonic for the diagnosis of dentine dysplasia type 1 (DD-1). In this report, we presented an adult case with DD-1 that had been left undiagnosed and the patient underwent dental implant therapy and orthodontic treatment, despite recognition of early tooth loss. The diagnosis of DD-1 was first established before an orthognathic surgery to correct the facial skeletal deformity. We also reviewed the clinicopathological aspects of this disease and clinical dental implications for this patient group.

Intraoperative injection of combined fibrin sealant and methylene blue dye for surgery of branchial cleft cysts: A case report.

Differential diagnosis of a lateral neck mass, especially in paediatric patients, should include branchial cleft cysts (BrCC). It is often difficult to identify and completely resect all cystic components, especially when the lesion becomes infected and/or gigantic. Incomplete excision increases the likelihood of recurrences. We reported a simple technique to facilitate the BrCC resection. Tisseel fibrin glue (FG: Baxter AG, Vienna, Austria) was mixed with methylene blue dye in inverse portion to the cyst size and/or the FG volume before injecting into the cystic lumen. After polymerisation of the dyed glue, the lesion was better visualised and extirpated in toto with the aid of the dye colour and gelatinisation by FG. An up-to-date diagnostic and therapeutic algorithm for BrCC was also presented.

Jagged1 inhibits osteoprotegerin expression by human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Notch signaling regulates bone homeostasis. The present study investigated the effect of Jagged1 on osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) expression in human periodontal ligament stromal (hPDL) cells. MATERIAL AND METHODS: hPDL cells were seeded on to indirect immobilized Jagged1 surfaces. OPG expression was determined using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Lentiviral small hairpin RNA particles against NOTCH2 were employed to inhibit NOTCH2 expression. Osteoclast formation was evaluated using RAW264.7 cells. An influence of exogenous OPG on osteogenic differentiation was determined by real-time polymerase chain reaction and Alizarin Red S staining. RESULTS: Jagged1 significantly enhanced HES1 and HEY1mRNA expression in a dose-dependent manner. Furthermore, OPG mRNA and protein levels dramatically decreased upon exposing hPDL cells to Jagged1. However, RANKL mRNA levels were not significantly different. There was also no difference in M-CSF and MCP-1mRNA expression. A γ-secretase inhibitor and cycloheximide treatment rescued Jagged1-attenuated OPG expression. Furthermore, shNOTCH2 overexpressing hPDL cells did not exhibit a decrease in OPG expression upon exposure to Jagged1, implying the involvement of NOTCH2 in the regulatory mechanism. Culturing RAW264.7 cells with conditioned medium from Jagged1-treated hPDL cells enhanced osteoclast formation compared with those cultured with conditioned medium of the control group. Lastly, OPG treatment did not influence osteogenic differentiation by hPDL cells. CONCLUSION: These results suggest that Jagged1 activates Notch signaling in hPDL cells, leading to decreased OPG expression. This may imply an indirect role of Jagged1 on the regulation of osteoclast differentiation via hPDL cells.