Faculty Bibliography

OBJECTIVES: This study compared the biomechanical fixation and bone-to-implant contact (BIC) of implants with different surfaces treatment (experimental - resorbable blasting media-processed nanometer roughness scale surface, and control - dual acid-etched) in a dog model. MATERIAL AND METHODS: Surface characterization was made in six implants by means of scanning electron microscopic imaging, atomic force microscopy to evaluate roughness parameters, and X-ray photoelectron spectroscopy (XPS) for chemical assessment. The animal model comprised the bilateral placement of control (n=24) and experimental surface (n=24) implants along the proximal tibiae of six mongrel dogs, which remained in place for 2 or 4 weeks. Half of the specimens were biomechanically tested (torque), and the other half was subjected to histomorphologic/morphometric evaluation. BIC and resistance to failure measures were each evaluated as a function of time and surface treatment in a mixed model ANOVA. RESULTS: Surface texturing was significantly higher for the experimental compared with the control surface. The survey XPS spectra detected O, C, Al, and Ti at the control group, and Ca ( approximately 0.2- 0.9%) and P ( approximately 1.7- 4.1%) besides O, C, Al, and Ti at experimental surfaces. While no statistical difference in BIC was found between experimental and control surfaces or between 2 and 4 weeks in vivo, both longer time and use of experimental surface significantly increased resistance to failure. CONCLUSIONS: The experimental surface resulted in enhanced biomechanical fixation but comparable BIC relative to control, suggesting higher bone mechanical properties around the experimental implants.

ABSTRACT: This article focuses on current practices and controversy in the area of presurgical infant orthopedics in patients born with cleft lip and palate.

Purpose: Fracture is a frequent complication of resinous prostheses. The purpose of this study was to evaluate the effect of thickness on flexural strength of a resinous prosthesis containing a prosthetic tooth. Materials and Methods: Beam-shaped specimens 65-mm long, 12-mm wide, and 1, 2, 3, 4, or 6 mm in thickness were made from high-impact strength polymethyl methacrylate denture base material, each containing a resin-based molar prosthetic tooth at the center of the beam. A group of 3-mm-thick specimens without a prosthetic tooth (n = 7) were also made. Specimens were aged artificially, loaded in three-point flexure, examined fractographically, and analyzed. Results: The 1- and 2-mm-thick beams underwent considerable deformation at low loads. Maximum loads varied considerably from 0.6 kg (1-mm beams) to 38 kg (6-mm beams). The 3-, 4-, and 6-mm beam groups all underwent brittle fracture, with mean relative flexural strengths of approximately 73 MPa. Denture teeth reduced the relative flexural strength of resin beams by 0.7x. Fracture initiation sites were generally at tiny surface defects, but did not directly involve denture teeth. Denture resin fracture toughness was 3.2 MPa m1/2, and modulus of rupture was 104 MPa. Conclusion: Denture teeth substantially decreased the strength of resinous beams. Increased thickness markedly increased the load-bearing capacity of resinous beams containing denture teeth. Beams less than 2 mm in thickness with denture teeth were weakened substantially more than comparable beams of 2 mm or more in thickness. Surface finish was of critical importance. Fracture toughness was calculated fractographically, facilitating future forensic examination of clinically failed resinous prostheses. Int J Prosthodont 2012;25:53-59.

BACKGROUND:Recently, the supraclavicular artery island flap has gained popularity as a regional flap for head and neck reconstruction. During clinical follow-up, some patients report referred sensation to the shoulder when there is contact with the flap skin island surface. The authors examine the anatomical origin/characteristics of the supraclavicular nerves (C3-4) to this flap and its relationship to the flap pedicle and anatomical boundaries. METHODS:SAI flap harvest and nerve dissection was performed in seven fresh frozen cadavers (n = 10) using loupe magnification in order to further elucidate the sensory nerve branches in a typical SAI flap. RESULTS:Branches of the supraclavicular nerve innervating the SAI flap were found to emerge from the deep fascia at a separate location from the vascular pedicle with the major nerve root exiting underneath the sternocleidomastoid muscle near the midpoint of the muscle belly. The nerve branches proximal to the pedicle with one branch exiting anterior to the flap and another running axially along the length of the flap. The majority (9/10) flaps had a major cutaneous nerves located 1-2 cm anterior to the pedicle. One (1/10) of the flaps had a major cutaneous nerve located 1-2 cm posterior to the pedicle toward the trapezius muscle. In 3 of the 10 flaps, smaller cutaneous nerves were also found posterior to the pedicle in a more distal location of the flap. CONCLUSIONS:The supraclavicular nerves innervating the SAI flap are easily identifiable and can be preserved or ligated, depending on the desired flap function, when present close to the pedicle. Further clinical investigation is warranted to confirm the potential benefit of using the SAI flap as a neurotized regional flap for head/neck reconstruction.

BACKGROUND: Injuries to the face can potentially lead to destruction of vital structures, with devastating sequelae to the patient. Facial fractures, especially of the midface, are often complicated by ocular injuries. The purpose of this study was to systematically review the literature to better understand specific fracture patterns associated with ocular injuries, including visual impairment and blindness. METHODS: The PubMed, EMBASE, and Cochrane databases from January of 2004 to April of 2010 were systematically reviewed to identify relevant studies. Only those that investigated facial fractures with concomitant ocular injuries, visual impairment, and/or blindness were included. Studies that described nonfacial fractures or those that only focused on the function of extraocular muscles were excluded. Case reports, nonsystematic reviews, and studies with fewer than 10 patients were also excluded. RESULTS: Eleven articles met study criteria and were included for analysis. There were a total of 14,535 patients, with an average of 1211 patients (range, 39 to 4426) per study. Level of evidence included levels II (n = 1 study), III (n = 1), and IV (n = 9). The mean reported rate of acute visual loss was 1.7 percent. Periorbital and orbital blowout fractures were more often complicated by ocular injuries compared with other facial fracture patterns. High-impact zygomatic fractures were most commonly associated with blindness. CONCLUSIONS: Existing studies exploring ocular injuries, visual impairment, and blindness associated with facial fractures offer conflicting data. Specifically directed studies are required so that significant correlations between specific fracture patterns and specific ocular injuries can be drawn. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

OBJECTIVES: To evaluate the effect of insertion torque on micromotion to a lateral force in three different implant designs. MATERIAL AND METHODS: Thirty-six implants with identical thread design, but different cutting groove design were divided in three groups: (1) non-fluted (no cutting groove, solid screw-form); (2) fluted (90 degrees cut at the apex, tap design); and (3) Blossom() (Patent pending) (non-fluted with engineered trimmed thread design). The implants were screwed into polyurethane foam blocks and the insertion torque was recorded after each turn of 90 degrees by a digital torque gauge. Controlled lateral loads of 10 N followed by increments of 5 up to 100 N were sequentially applied by a digital force gauge on a titanium abutment. Statistical comparison was performed with two-way mixed model ANOVA that evaluated implant design group, linear effects of turns and displacement loads, and their interaction. RESULTS: While insertion torque increased as a function of number of turns for each design, the slope and final values increased (P<0.001) progressively from the Blossom to the fluted to the non-fluted design (M +/- standard deviation [SD]=64.1 +/- 26.8, 139.4 +/- 17.2, and 205.23 +/- 24.3 Ncm, respectively). While a linear relationship between horizontal displacement and lateral force was observed for each design, the slope and maximal displacement increased (P<0.001) progressively from the Blossom to the fluted to the non-fluted design (M +/- SD=530 +/- 57.7, 585.9 +/- 82.4, and 782.33 +/- 269.4 mum, respectively). There was negligible to moderate levels of association between insertion torque and lateral displacement in the Blossom, fluted and non-fluted design groups, respectively. CONCLUSION: Insertion torque was reduced in implant macrodesigns that incorporated cutting edges, and lesser insertion torque was generally associated with decreased micromovement. However, insertion torque and micromotion were unrelated within implant designs, particularly for those designs showing the least insertion torque.

BACKGROUND: : Patients with syndromic craniosynostosis and midface hypoplasia are often treated with Le Fort III advancement. The authors present four patients with extraordinarily long-term follow-up (in excess of 20 years). METHODS: : An institutional review board-approved retrospective chart review was performed on all patients with syndromic craniofacial synostosis who underwent Le Fort III advancement. Patients with greater than 20 years of cephalometric and photographic records were identified. Lateral cephalograms were obtained preoperatively, immediately postoperatively, at 1-year follow-up, and at long-term follow-up. Cephalograms were traced, digitized, and averaged. Fifty cephalometric landmarks were identified for serial measurements. RESULTS: : Of the four patients identified, one had Apert syndrome and three had Crouzon syndrome. Average age at the time of Le Fort III advancements was 11 years (range, 4 to 20 years). Average length of postoperative follow-up was 25 years (+/-5 years). No patient had significant anterior midfacial growth following Le Fort III advancement. Both young patients (<10 years) had substantial vertical inferior midfacial growth after advancement. CONCLUSIONS: : These data demonstrate that the Le Fort III segment of children with syndromic craniosynostosis does not grow significantly forward. Moreover, the traditional Le Fort III osteotomy does not provide the amount of midface advancement necessary to avoid phenotypic recidivism in these syndromic patients. This study also suggests that patients undergoing Le Fort III advancement appear to have zygomatic effacement and ptosis of the overlying soft tissue with deepening of the facial folds; collectively, it is suggested that these changes give the appearance of accelerated facial aging. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, V

OBJECTIVE: Catheter-related infection remains a cause of morbidity in the use of external ventricular drains (EVDs). The aim of this retrospective single-center study was to assess the rate and factors related to ventriculostomy infections in the setting of the published literature. METHODS: Patients that underwent EVD placement in a single-center were retrospectively reviewed. Diagnosis, treatment, hospital course, and infection-related data were collected and analyzed in reference to ventriculitis rates. The protocols for EVD placement and maintenance were reviewed. RESULTS: Of 343 patients, 12 acquired an EVD infection. No significant differences existed between those with and without ventriculitis for age, sex, underlying diagnosis, or concomitant systemic infection. Although not significant, concomitant systemic infection existed in 4.7% of patients with ventriculitis versus 1.5% without. There was a significant difference in length of EVD placement in patients with ventriculitis (20.9 +/- 15.3 days) versus those without (12.1 +/- 18.2; P = 0.005). Coagulase-negative Staphylococcus and Staphylococcus aureus represented the most commonly associated pathogens. With an overall cumulative incidence of 3.5%, our rate compared favorably to the published literature (cumulative incidence 9.5%; range, 3.9%-23.2%). CONCLUSIONS: Catheter-related infection remains an important complication of EVD placement. Of factors evaluated, length of time of catheter placement has the most notable relationship to infection incidence, suggesting that early drain removal should be a goal whenever medically appropriate.

BACKGROUND:Preoperative lymphoscintigraphy for sentinel node biopsy (SNB) combined with intra-operative gamma-probe detection often identifies nodes within the pelvis. This study investigates the role of pelvic SNB harvest. METHODS:Retrospective review of eighty-two stage I/II melanoma patients with primary tumour on the lower limb and trunk who underwent groin SNB, either inguinal or pelvic or both, over a three year period. RESULTS:Of the 82 patients, 19 had positive SNBs (24%), all of which were inguinal nodes. None of the 11 patients with pelvic nodes removed had a positive pelvic node. The median follow-up period was 18 months (SD: 10.8; range: 8-43). Although the complication rate was higher following pelvic SNB, the difference was not statistically significant (p > 0.5). The average operative time for an inguinal SNB was 92 min, and increased significantly to 134 min for a pelvic SNB (p < 0.0001). Lymphoscintigraphy of trunk and thigh melanomas identified individual tracks to be leading directly from the tumour to a pelvic node(s). However, when the primary tumour was located at or below the knee, pelvic nodes identified by lymphoscintigraphy appeared to be second level nodes. CONCLUSION/CONCLUSIONS:A lymphoscintigraphy protocol that includes dynamic images obtained in frequent intervals following injection of the radiotracer combined with thorough preoperative analysis of the lymphoscintigraphy scans and effective communication between the radiologist and the surgeon allows accurate identification of the primary tracks and prevent unnecessary harvest of second echelon pelvic lymph nodes. In patients with significant co-morbidities due consideration is required before harvesting pelvic sentinel nodes.