Faculty Bibliography

Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macro-geometries (24 with a specific cutting flute design - Blossom group; 24 with a self-tapping design - DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P<0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P=0.58 for bone-to-implant contact (BIC) and P=0.52 for bone area fraction occupied (BAFO); at 6 weeks, P=0.55 for BIC and P=0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern.

OBJECTIVES: This study aims to evaluate bone response to an implant surface modified by 1alpha,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. MATERIAL AND METHODS: Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10(-8), 10(-7) and 10(-6) M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). RESULTS: The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). CONCLUSIONS: The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies.

PURPOSE: Local anesthetic is often used for perioperative pain control. Thrombin serves as a carrying medium for sustained release of antibiotics, chemotherapy, and growth factors. We tested the hypothesis that local anesthetic pain relief can be prolonged with the adjunct use of thrombin. METHODS: A prospective single-blinded clinical study was performed. Patients undergoing elective hand surgery inclusive of carpal tunnel release, excision of ganglion cyst, trigger finger release, and excision of mucous cyst under local block were enlisted. Before closure, patients received 1 of the following combinations: (1) control with oral analgesics, (2) 5 mL of 2% xylocaine, (3) 5 mL of 0.5% bupivacaine, (4) 2.5 mL of 2% xylocaine with 2.5 mL of 0.5% bupivacaine (XB), (5) thrombin with 5 mL of 2% xylocaine (XT), (6) thrombin with 5 mL of 0.5% bupivacaine (BT), and (7) thrombin with 2.5 mL of 2% xylocaine and 2.5 mL of 0.5% bupivacaine (XBT). There were 7 patients in each group, and patient demographics were similar between groups. Outcome measures included postanesthesia care unit (PACU) time, pain level, and number of pain pills required. RESULTS: Compared with oral analgesics alone, mean (SD) postoperative pain levels were reduced by 33.3% (8.9%) by xylocaine, 69.1% (8.7%) by bupivacaine, and 45.7% (9.4%) by XB. When thrombin was added, pain levels were further reduced by 69.9% by XT (P < 0.001), 23.1% by BT (P = 0.071), and 50.5% by XBT (P < 0.001) compared with their nonthrombin counterparts. In addition, PACU time was decreased by 34.8% by XT (P = 0.003) and 19.7% by XBT (P = 0.013) compared with xylocaine and XB, respectively. However, there was no difference in total pain pills needed between xylocaine, bupivacaine, and XB when administered with and without thrombin. CONCLUSIONS: The addition of topical thrombin to local anesthetic at the end of elective hand surgery provides for sustained postoperative pain control. Patients in this study who received thrombin and local anesthetic before wound closure had lower pain levels and were discharged from the PACU sooner than those who received local anesthetic alone. LEVEL OF EVIDENCE: Therapeutic level 2.

BACKGROUND: Gunshot injuries to the craniomaxillofacial region are a challenge to the trauma and reconstructive surgeon. Although management of these injuries has been standardized and early rather than late intervention is advocated, the patient characteristics before, during, and after have been poorly elucidated. METHODS: A prospectively maintained Level I trauma center database was queried as to gunshot wounds of the craniomaxillofacial skeleton. Over a five-year period (2007-2011), 168 patients were identified with these injuries. Charts were reviewed as to demographics, presentations, and outcomes and these were tested for significant relationships with hospital length of stay, numbers and types of procedures, morbidity, and mortality. RESULTS: Gunshot wounds to the craniofacial skeleton resulted in 71 deaths in this patient population. Those that died were significantly older, presented with a lower GCS, had a shorter LOS, and a higher INR than those that lived. Subgroup analysis of mechanism demonstrated mortality was more likely to occur as a result of self-inflicted injury in whites and due to assault in the African-American population. CONCLUSIONS: Data gathered from this study disputes some commonly held beliefs regarding the epidemiology of gunshot injuries and should allow for better characterization of which outcomes are consistent with which presentations.

INTRODUCTION: Cancer pain creates a poor quality of life and decreases survival. The basic neurobiology of cancer pain is poorly understood. Adenosine triphosphate (ATP) and the ATP ionotropic receptor subunits, P2X2 and P2X3, mediate cancer pain in animal models; however, it is unknown whether this mechanism operates in human, and if so, what the relative contribution of P2X2- and P2X3-containing trimeric channels to cancer pain is. Here, we studied head and neck squamous cell carcinoma (HNSCC), which causes the highest level of function-induced pain relative to other types of cancer. RESULTS: We show that the human HNSCC tissues contain significantly increased levels of ATP compared to the matched normal tissues. The high levels of ATP are secreted by the cancer and positively correlate with self-reported function-induced pain in patients. The human HNSCC microenvironment is densely innervated by nerve fibers expressing both P2X2 and P2X3 subunits. In animal models of HNSCC we showed that ATP in the cancer microenvironment likely heightens pain perception through the P2X2/3 trimeric receptors. Nerve growth factor (NGF), another cancer-derived pain mediator found in both human and mouse HNSCC, induces P2X2 and P2X3 hypersensitivity and increases subunit expression in murine trigeminal ganglion (TG) neurons. CONCLUSIONS: These data identify a key peripheral mechanism in cancer pain and highlight the clinical potential of specifically targeting nociceptors expressing both P2X2 and P2X3 subunits (e.g., P2X2/3 heterotrimers) to alleviate cancer pain.

The present study aimed to characterize the mechanical response of beagle sartorius muscle fibers under strain rates that increase logarithmically (0.1mm/min, 1mm/min and 10mm/min), and provide an analysis of the fracture patterns of these tissues via scanning electron microscopy (SEM). Muscle tissue from dogs' sartorius was excised and test specimens were sectioned with a lancet into sections with nominal length, width, and thickness of 7, 2.5 and 0.6mm, respectively. Trimming of the tissue was done so that the loading would be parallel to the direction of the muscle fiber. Samples were immediately tested following excision and failures were observed under the SEM. No statistically significant difference was observed in strength between the 0.1mm/min (2.560+/-0.37MPa) and the 1mm/min (2.702+/-0.55MPa) groups. However, the 10mm/min group (1.545+/-0.50MPa) had a statistically significant lower strength than both the 1mm/min group and the 0.1mm/min group with p<0.01 in both cases. At the 0.1mm/min rate the primary fracture mechanism was that of a shear mode failure of the endomysium with a significant relative motion between fibers. At 1mm/min this continues to be the predominant failure mode. At the 10mm/min strain rate there is a significant change in the fracture pattern relative to other strain rates, where little to no evidence of endomysial shear failure nor of significant motion between fibers was detected.

Laparoscopic cholecystectomy is the gold standard treatment option for cholelithiasis. In order to properly assess for the complications related to the procedure, an understanding of the normal biliary anatomy, its variants and the normal postoperative imaging is essential. Radiologist must be aware of benefits and limitations of multiple imaging modalities in characterizing the complications of this procedure as each of these modalities have a critical role in evaluating a symptomatic post-cholecystectomy patient. The purpose of this article is describe the multi-modality imaging of normal biliary anatomy and its variants, as well as to illustrate the imaging features of biliary, vascular, cystic duct, infectious as well as miscellaneous complications of laparoscopic cholecystectomy. We focus on the information that the radiologist needs to know about the radiographic manifestations of potential complications of this procedure.

The purpose of this report is to present a case series of gingiva-colored abutments utilized to meet patients, esthetic needs. The color of the abutment was determined by evaluating the color of the patients, marginal gingiva using a digital shade guide. Thereafter, anodic oxidation was performed on computer-aided design/computer-assisted manufacture abutments. The baseline digital color information was compared with the color of the gingiva after 1.5 years in three patients. The gingival colors as well as the marginal bone and soft tissue levels after 1.5 years were comparable to the baseline values. Thus, the gingiva-colored abutments obtained by anodic oxidation provided improved esthetics, especially for patients with thin gingival biotypes.

Application of recombinant human bone morphogenetic protein-2 (rhBMP-2) to implant surfaces has been of great interest due to its osteoinductive potential. However, the optimal coating methodology has not been clarified. The objective of the study was to determine whether the application of rhBMP-2 onto plasma-sprayed hydroxyapatite implant surfaces by immersion in protein solution prior to implant installation would result in significantly improved bone apposition. Using a sheep iliac model, titanium (Ti) and plasma-sprayed calcium phosphate coated (PSCaP) implants uncoated and coated with rhBMP-2 were assessed for their osteogenic effects in the peri-implant area over time in terms of osseointegration and de novo bone formation. After 3 and 6 weeks post-operatively, the samples were retrieved and were subjected to bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) evaluation. When rhBMP-2 was applied to the PSCaP surface, significant increases in BIC and BAFO were observed at 3 weeks in vivo, whereas when adsorbed directly onto the titanium implant surface, rhBMP-2 did not as effectively improve the bone response (although significantly higher than control Ti). The outcomes of the present study suggested that the combination of plasma-sprayed calcium phosphate surface and rhBMP-2 coating significantly enhanced osseointegration, which validated the postulated hypothesis.