Two-Year Follow-up Comparison of Three Surgical Techniques for Implant Placement in Posterior Maxilla with Limited Alveolar Bone Height.

PURPOSE: The aim of this pilot study was to compare three surgical techniques (bicortical fixation, unicortical fixation, and indirect sinus elevation) for implant placement in the posterior maxilla with limited alveolar bone height. This 2-year follow-up assessment on the implants of a previously published prospective clinical trial compared (1) restoration/implant stability among the three surgical groups, (2) intrasinus bone formation between the bicortical fixation and indirect sinus elevation groups, and (3) implant and prosthetic complications reported among the three groups. MATERIALS AND METHODS: For the original prospective study, 38 patients were recruited, exhibiting 7 to 11 mm of alveolar bone coronal to the sinus floor as confirmed by preoperative CBCT, and 45 implants were placed using three randomly assigned surgical techniques. No patient received more than two implants, which were placed in opposite sides of the maxilla and using different surgical techniques. At the 2-year follow-up assessment, 32 patients with 37 implants were evaluated. The 2-year follow-up restoration/implant stability was measured with the Periotest stability measuring device. Intrasinus bone formation was measured from the 2-year follow-up CBCT in comparison to the preoperative CBCT. Clinical examination was also performed to identify loose implants and/or implant crowns and signs of peri-implantitis. Patients were interviewed regarding complications experienced with the study implants/restorations, and electronic charts were thoroughly reviewed to identify records of complications. RESULTS: No significant difference in restoration/implant stability (Periotest value [PTV]) was seen between the bicortical fixation, unicortical fixation, and indirect sinus elevation groups (-1.69 [0.80], -1.76 [0.80], -2.22 [0.60], respectively, P = .76) at the 2-year follow-up. The indirect sinus elevation group showed more intrasinus horizontal (1.99 [0.17] vs 1.47 [0.16] mm, P = .03) and vertical (3.15 [0.43] vs 2.35 [0.38] mm, P = .13) bone gain compared with the bicortical fixation group. CONCLUSION: Within the limitations of this study, placing implants using a bicortical fixation surgical technique in moderately limited alveolar bone height (7 to 11 mm) was not significantly different from the other two techniques and may be a feasible option with limited risks while allowing longer implant placement and negating the need for indirect sinus augmentation, which is accompanied by additional expense and surgical morbidity to the patient.

Defining the left ventricular base in mitral valve prolapse: impact on systolic function and regurgitation.

In bileaflet mitral valve prolapse (BMVP) systolic leaflet displacement creates a pocket of blood on the left ventricular (LV) side of the leaflets, but on the atrial side of the annulus. This blood is excluded from the LV end-systolic volume if the mitral valve annulus is used to determine the most basal extent of the LV. The purpose of this study is to describe the quantitative implications of defining the LV base on mitral regurgitant severity and LV systolic function in BMVP. In 30 consecutive patients (53% male, 58 ± 14 years) with BMVP, LV endocardial and epicardial borders were determined from SSFP images. The LV base at end-systole was defined by the "Functional" method (at the mitral valve annulus) or the "Anatomic" method (at the mitral valve leaflets). Regurgitant volume was the difference between the LV stroke volume and mean forward flow. LV myocardial strain measurements were determined from the short axis endocardial and epicardial borders. The "Functional" method resulted in higher regurgitant volumes (mean difference: 22 ml, range 0-40 ml) and higher ejection fractions (mean difference: 9%, range 0-21%). The correlation between LV end-diastolic volume and regurgitant volume was better with the "Functional" method (r = 0.79, p < 0.0001) than the "Anatomic" method (r = 0.67, p < 0.0001). The correlation between global myocardial radial strain and LV EF was better with the "Functional" method (r = 0.86, p < 0.0001) than the "Anatomic" method (r = 0.68, p < 0.0001). In BMVP, the base of the LV should be defined at the level of the mitral valve annulus so that regurgitant volume most accurately reflects the functional significance of the mitral valve disease and LVEF most accurately reflects global systolic LV function. Defining the basal extent of the LV at the mitral valve leaflets leads to substantially lower regurgitant volumes and lower ejection fractions that could have important clinical consequences.

Comparison of Initial Implant Stability of Implants Placed Using Bicortical Fixation, Indirect Sinus Elevation, and Unicortical Fixation.

PURPOSE: The aim of this study was to determine if self-threading dental implants placed using stopper drills to bicortically engage both the alveolar crest and sinus floor (bicortical fixation) achieved primary and/or secondary stability comparable to that of short implants only engaging alveolar crest cortical bone (unicortical fixation) or implants engaging both the crest and sinus floor but via greenstick fracture and grafting (indirect sinus elevation). MATERIALS AND METHODS: Thirty-eight patients exhibiting 7 to 11 mm of bone coronal to the sinus floor as confirmed by preoperative CBCT were recruited. Forty-five implants were randomly assigned to one of the placement techniques. No patient received more than two implants, which were placed in opposite sides of the maxilla while using different surgical techniques. An Osstell ISQ was employed immediately after implant placement to measure stability six times in a buccolingual dimension. Secondary stability was measured at stage-two surgery after a 3- to 6-month healing period. RESULTS: The greatest primary implant stability was achieved via indirect sinus elevation. However, no statistically significant difference was found among the three surgical techniques (P = .13; bicortical fixation: 71.4 [standard error = 2.1]), unicortical fixation: 69.6 [2.1], indirect sinus elevation: 75.9 [2.3]). The three techniques had similar secondary stability (P > .999; 79.9 [1.2], 80.0 [1.2], and 80.0 [1.3], respectively). Baseline residual ridge height measured on CBCT was similar (P = .1; 8.8, 9.9, and 9.4 mm, respectively), but implant diameter and length placed in the maxilla differed (P = .03/P < .001; 4.7/11.4 mm, 4.3/8.1 mm, and 4.7/11.8 mm, respectively). Primary implant stability was significantly correlated to CBCT bone density (r = 0.37). CONCLUSION: Primary and secondary implant stabilities of bicortical fixation did not differ significantly from those of unicortical fixation and indirect sinus elevation. However, use of the bicortical fixation technique is warranted since it is simpler and more economical than indirect sinus elevation; plus, it allows for longer implants than the unicortical fixation while yielding similar secondary implant stability.

Gingival crevicular blood as a source to screen for diabetes control in a dental office setting.

UNLABELLED: screen for diabetes control, this study compared glycosylated hemoglobin (HbAlc) levels found in GCB and serum. Methods: Patients diagnosed (n= 29), with diabetes received a venipuncture on the finger and serum blood (METHODS) obtained was tested for HbAlc status chair-side. GCB (test) was collected at site(s) with evidence of bleeding after probing and the HbAlc value was determined in the same manner as with the serum blood. Results: There was a significant correlation between serum blood and GCB using the HbAlc test. The Pearson RESULTS: tion was 0.98 (P< 0.0001). The Altman-Bland bias was -0.21 (P= 0.0095), indicating that on average, the GCB method slightly underestimated the venipuncture serum (control) method for determining HbA1c values. The Altman-Bland 95% agreement interval ranged from -1.02 to 0.6. Furthermore, the HbAlc values were independent of the gingival sites used for collection with intra-patient GCB values exhibiting a correlation value between sites of 0.91 (P< 0.0001).

A pilot study of glycosylated hemoglobin levels in periodontitis cases and healthy controls.

BACKGROUND: Periodontitis is associated with glycemic control in patients with diabetes. The purpose of this study was to determine if glycosylated hemoglobin is elevated in patients with periodontitis who have not been diagnosed with diabetes. METHODS: Glycosylated hemoglobin (HbA1c) was assessed using a chairside test in 59 adults without diabetes but with periodontitis (having at least five teeth with probing depth [PD] > or =5 mm, bleeding on probing [BOP], and clinical attachment or radiographic bone loss) and 53 healthy controls (PDs < or =4 mm and BOP < or =15%). Groups were compared using the t test and linear regression. Patients with HbA1c levels > or =6% were compared using the Fisher exact test and logistic regression. RESULTS: Periodontitis cases were more likely than controls to be male (68% versus 38%; P = 0.002) and current or former smokers (P = 0.002). Cases had significantly higher body mass index (BMI) than controls (27.6 kg/m(2) versus 25.5 kg/m(2); P = 0.018) but were of similar age (51.3 years versus 50.9 years; P = 0.89). Unadjusted mean HbA1c levels did not differ significantly between cases and controls (5.66% +/- 0.56% versus 5.51% +/- 0.44%; P = 0.12). After adjustments for age, gender, BMI, and current smoking, mean HbA1c was significantly higher in cases (between-group difference, 0.21%; P = 0.046). A higher proportion of cases (27.3%) than controls (13.2%) had HbA1c values > or =6%, although this difference was not statistically significant (P >0.1). CONCLUSIONS: Periodontitis is associated with a slight elevation in glycosylated hemoglobin. The clinical significance of this difference remains to be determined. This preliminary finding is consistent with earlier reports that periodontitis is associated with elevated blood glucose in adults without diabetes and may increase one's risk for type 2 diabetes.

Twisted gastrulation limits apoptosis in the distal region of the mandibular arch in mice.

The mandibular arch (BA1) is critical for craniofacial development. The distal region of BA1, which gives rise to most of the mandible, is dependent upon an optimal level of bone morphogenetic protein (BMP) signaling. BMP activity is modulated in the extracellular space by BMP-binding proteins such as Twisted gastrulation (TWSG1). Twsg1(-/-) mice have a spectrum of craniofacial phenotypes, including mandibular defects that range from micrognathia to agnathia. At E9.5, the distal region of the mutant BA1 was prematurely and variably fused with loss of distal markers eHand and Msx1. Expression of proximal markers Fgf8 and Barx1 was expanded across the fused BA1. The expression of Bmp4 and Msx2 was preserved in the distal region, but shifted ventrally. While wild type embryos showed a gradient of BMP signaling with higher activity in the distal region of BA1, this gradient was disrupted and shifted ventrally in the mutants. Thus, loss of TWSG1 results in disruption of the BMP4 gradient at the level of signaling activity as well as mRNA expression. Altered distribution of BMP signaling leads to a shift in gene expression and increase in apoptosis. The extent of apoptosis may account for the variable degree of mandibular defects in Twsg1 mutants.

Cytotype regulation in Drosophila melanogaster: synergism between telomeric and non-telomeric P elements.

The X-linked telomeric P elements TP5 and TP6 interact synergistically with non-telomeric P elements to repress hybrid dysgenesis. In this repression, the telomeric P elements exert maternal effects, which, however, are not sufficient to establish synergism with the non-telomeric P elements. Once synergism is established, the capacity to repress dysgenesis in the offspring of a cross persists for at least two generations after removing the telomeric P element from the genotype. At the molecular level, synergism between telomeric and non-telomeric P elements is correlated with effective elimination of P-element mRNA in the germ line. Maternally transmitted mutations in the genes aubergine, piwi and Suppressor of variegation 205 [Su(var)205] block the establishment of synergism between telomeric and non-telomeric P elements, and paternally transmitted mutations in piwi and Su(var)205 disrupt synergism that has already been established. These findings are discussed in terms of a model of cytotype regulation of P elements based on Piwi-interacting RNAs (piRNAs) that are amplified by cycling between sense and antisense species.

Cytotype regulation by telomeric P elements in Drosophila melanogaster: interactions with P elements from M' strains.

P strains of Drosophila are distinguished from M strains by having P elements in their genomes and also by having the P cytotype, a maternally inherited condition that strongly represses P-element-induced hybrid dysgenesis. The P cytotype is associated with P elements inserted near the left telomere of the X chromosome. Repression by the telomeric P elements TP5 and TP6 is significantly enhanced when these elements are crossed into M' strains, which, like P strains, carry P elements, but have little or no ability to repress dysgenesis. The telomeric and M' P elements must coexist in females for this enhanced repression ability to develop. However, once established, it is transmitted maternally to the immediate offspring independently of the telomeric P elements themselves. Females that carry a telomeric P element but that do not carry M' P elements may also transmit an ability to repress dysgenesis to their offspring independently of the telomeric P element. Cytotype regulation therefore involves a maternally transmissible product of telomeric P elements that can interact synergistically with products from paternally inherited M' P elements. This synergism between TP and M' P elements also appears to persist for at least one generation after the TP has been removed from the genotype.