Effect on Bone Architecture of Marginal Grooves in Dental Implants Under Occlusal Loaded Conditions in Beagle Dogs.

The aim of this study was to clarify whether marginal grooves on dental implants affect osseointegration, bone structure, and the alignment of collagen fibers to determine bone quality under loaded conditions. Anodized Ti-6Al-4V alloy dental implants, with and without marginal grooves (test and control implants, respectively), were used (3.7 × 8.0 mm). Fourth premolars and first molars of 6 beagle mandibles were extracted. Two control and test implants were placed in randomly selected healed sites at 12 weeks after tooth extraction. Screw-retained single crowns for first molars were fabricated. Euthanasia was performed at 8 weeks after the application of occlusal forces. Implant marginal bone level, bone to implant contact (BIC), bone structure around dental implants, and the alignment of collagen fibers determining bone quality were analyzed. The marginal bone level in test implants was significantly higher than that in control implants. Occlusal forces significantly increased BIC in test implants ( P = .007), whereas BIC did not change in control implants, irrespective of occlusal forces ( P = .303). Moreover, occlusal forces significantly increased BIC in test implants compared with control implants ( P = .032). Additionally, occlusal forces preferentially aligned collagen fibers in test implants, but not control implants. Hence, marginal grooves on dental implants have positive effects on increased osseointegration and adapted bone quality based on the preferential alignment of collagen fibers around dental implants under loaded conditions.

Maxillary verrucous carcinoma coincident with cervical lymph node metastasis of colon adenocarcinoma.

Cervical lymph node metastasis is an extremely rare event in oral verrucous carcinoma. Isolated cervical lymph node metastasis of colon cancer is also rare. This article describes a case of maxillary verrucous carcinoma accompanied by colon adenocarcinoma that metastasized to a cervical lymph node in a 69-year-old Japanese woman. During preoperative evaluation for maxillary verrucous carcinoma, enlarged cervical lymph nodes and colon cancer were suspected by positron emission tomography. Colonoscopy with biopsies confirmed primary colon adenocarcinoma. Left radical neck dissection, partial maxillectomy, and full-thickness skin graft to the mucosa of the upper lip were performed before treatment of colon adenocarcinoma. Cervical lymph nodes showed metastasis from colon adenocarcinoma, and right hemicolectomy was performed. This is the first case report of synchronous oral verrucous carcinoma and colon adenocarcinoma with cervical lymph node metastasis.