The KPG index--a novel 3D classification system for maxillary canine impactions.

INTRODUCTION: Advancements in Cone Beam Computed Tomography (CBCT) have improved localization of impacted canines. The KPG index is the first 3-D classification system for classifying the position of canines based on their distance from the norm (1). The aim of this study was to determine if this index provides an estimate of the time necessary to treat an impacted canine using closed eruption. MATERIALS AND METHODS: CBCT scans of 28 impacted canines at The University of Texas School of Dentistry at Houston Department of Orthodontics were classified using the KPG index. The scores and categories were compared to the time from surgical exposure to proper positioning. RESULTS: Four canines were classified as "Easy," 11 as "Moderate," 9 as "Difficult," and 4 as "Extremely Difficult." Average treatment times associated in months were: "Easy"--11.23, "Moderate"--11.36, "Difficult"--12.76, and "Extremely Difficult"--13.23. CONCLUSIONS: The KPG index currently cannot be confirmed as an accurate means of estimating treatment time for an impacted canine. Further verification studies should include larger sample sizes and compare differing mechanics. However, there are limitations to 2-D imaging; therefore, the 3-D CBCT images and the KPG index, with further validation, will become increasingly valuable to orthodontists.

Differences in virological response to pegylated interferon and ribavirin between hepatitis C virus (HCV)-monoinfected and HCV-HIV-coinfected patients.

BACKGROUND: Suboptimal doses of ribavirin have been suggested to explain the diminished efficacy of pegylated interferon (PEG-IFN) plus ribavirin in hepatitis C virus (HCV)-HIV-coinfected patients. METHODS: A cohort of 104 coinfected patients and an age-, sex- and genotype-matched cohort of HCV-monoinfected patients (n = 104) were compared. All patients received PEG-IFN-alpha2a 180 microg/week plus ribavirin 800-1,200 mg daily (HCV genotype 2/3 patients received 800 mg daily and those with genotype 1/4 received 1,000-1,200 mg daily) for 48 weeks (24 weeks for monoinfected patients with genotypes 2/3). HCV RNA levels were determined qualitatively at weeks 4, 12, 24, 48 and 72 and quantified monthly until week 12. RESULTS: The coinfected cohort had more advanced liver disease and lower body weight. HCV genotype 1 patients coinfected with HIV showed higher levels of HCV RNA than monoinfected patients. A significantly higher proportion of coinfected patients interrupted the prescribed treatment period prematurely (84% versus 98%). During the first 12 weeks, smaller decreases in HCV RNA levels were observed in coinfected patients. Among patients with HCV genotype 1, coinfected patients achieved lower rates of early virological response (64% versus 87%), end-of-treatment response (47.3% versus 80%) and sustained virological response (SVR; 27.3% versus 56.4%), but not rapid virological response (RVR). HCV-HIV-coinfected patients with HCV genotype 2/3 achieved significantly lower rates of RVR (52% versus 88%). Multivariate analysis identified RVR, gender and liver fibrosis as independent predictors of SVR. CONCLUSIONS: Differences in efficacy of PEG-IFN-alpha2a plus ribavirin treatment between HCV-HIV-coinfected and HCV-monoinfected patients were maintained despite optimized ribavirin dose.

Results of a study of prolonging treatment with pegylated interferon-alpha2a plus ribavirin in HIV/HCV-coinfected patients with no early virological response.

OBJECTIVE: To assess the efficacy and safety of an extended treatment period in HIV/hepatitis C virus (HCV)-coinfected patients without early virological response (EVR). METHODS: Patients received pegylated interferon (peg-INF)-alpha2a 180 microg/week plus ribavirin 800 mg/d for 12 weeks. Patients achieving EVR at week 12 continued under therapy for an additional 12 or 36 weeks depending on genotype. Patients without EVR were randomized to complete the standard treatment or treatment lasting 72 weeks (extension arm). RESULTS: One hundred and ten patients were included (mean age 38.7 years, mean weight 68 kg, 74% males, 74% on highly active antiretroviral therapy, mean CD4+ T-cell count 564 cells/mm3). Fifty-one patients harboured genotype 1, 44 genotype 2/3, and 15 genotype 4. Fifty-three had an HCV load >800,000 IU/ml. Premature interruptions occurred in 32.7%. EVR was achieved in 63.6% (51% in genotype 1, 88.6% in genotype 2/3, 33.3% in genotype 4). End-of-treatment response was 52.7% (47.2% in genotype 1, 68.2% in genotype 2/3, 26.7% in genotype 4). Sustained virological response (SVR) was achieved in 41.8% (37.3% in genotype 1, 54.6% in genotype 2/3, 20% in genotype 4). Only one patient allocated to the extended arm achieved SVR. The rate of drop-outs in the extension arm was 68%. The negative predictive value of EVR was 97.5%. CONCLUSIONS: This study shows no benefit of extending therapy in patients without EVR at week 12. Measures to improve adherence to HCV antiviral therapy should be considered when new approaches based on extended periods of treatment are investigated.

Early HCV dynamics on Peg-interferon and ribavirin in HIV/HCV co-infection: indications for the investigation of new treatment approaches.

OBJECTIVES: To describe the 28-day hepatitis C virus (HCV) kinetics under Pegylated-interferon (Peg-IFN) + ribavirin (RBV) therapy in HIV/HCV co-infected patients. To evaluate the predictive value of early virological response (EVR) of achieving a sustained virological response (SVR). To investigate the baseline mutations in the interferon sensitivity determining region (ISDR)2209-2248 in the non-structural 5A protein of HCV according to genotype. METHODS: Open, prospective trial including 28 co-infected patients with directly observed treatment with Peg-IFN + RBV. We assessed the predictive values of EVR (> or = 2 log10 of HCV decay or a negative qualitative test) at days 1, 7, 28 and in week 12 of the SVR. RESULTS: The SVR in an intention-to-treat analysis was 28.6% (genotype 1, 1/13; genotype 3, 6/10; genotype 4, 1/5). Patients who reached SVR presented a significantly faster HCV plasma viral load reduction compared to non-responders from the first 24 h [-1.06 log10 (interquartile range, -1.7 to -0.4) versus -0.05 log10 (interquartile range, -0.4 to +0.14) respectively; P = 0.002]. The median HCV viral load at week 12 was significantly different from that at baseline in responder and transient responders but not in non-responder patients. The positive predictive value was 100% within the first month and the best negative predictive value was 92% and 88.8% at weeks 4 and 12 respectively. The only genotype 1 responder patient had eight mutations in ISDR2209-2248. CONCLUSIONS: A very early HCV viral decay is observed in responder patients. An early virological response assessment at week 4 and 12 might be a useful tool in the clinical management of the co-infected population.

Mitochondrial effects of a 24-week course of pegylated-interferon plus ribavirin in asymptomatic HCV/HIV co-infected patients on long-term treatment with didanosine, stavudine or both.

BACKGROUND: It has been suggested that the addition of ribavirin (RBV) as a part of the treatment for chronic hepatitis C virus (HCV) in HIV co-infected patients on didanosine (ddI) or stavudine (d4T) might increase the nucleoside-induced impairment of mitochondrial function. DESIGN: Comparative study to investigate the impact on mitochondrial function of adding RBV to a long-term treatment with ddI, d4T or both in HCV/HIV non-cirrhotic, asymptomatic patients. We included 26 patients: 16 continued with their current antiretroviral therapy (control group) and 10 patients received a concomitant 24-week course of RBV plus pegylated interferon (PEG-IFN) alpha-2b therapy (HCV-treated group). METHODS: We assessed peripheral blood mononuclear cells mitochondrial DNA (mtDNA) content and mitochondrial respiratory chain (MRC) function at baseline and at 24 weeks of follow-up. In the HCV-treated group we performed additional determinations at 12 weeks during anti-HCV therapy and 24 weeks after finishing anti-HCV therapy. RESULTS: Times on ddI or d4T exposure were 194 +/- 54.9 and 131 +/- 66.5 weeks in the HCV-treated and control groups, respectively. There were no differences either in mtDNA content, the enzyme activity of MRC complexes or clinical parameters at baseline. Throughout the study, mitochondrial measurements remained stable within groups and without differences when we compared HCV-treated and control groups. CONCLUSIONS: In our study, the addition of RBV and PEG-IFN during a 24-week period in HCV/HIV non-cirrhotic, asymptomatic patients on long-term ddI, d4T or both had no impact on mitochondrial function. These findings could suggest that additional triggers are required to achieve a critical threshold in the degree of mitochondrial damage needed for symptoms to develop.

A longitudinal study of incremental expansion using a mandibular lip bumper.

A retrospective study using models was performed to evaluate the incremental expansion that occurred during mandibular lip bumper therapy in 44 adolescent patients. The purpose was to determine whether expansion occurs evenly between appointments or whether it attenuates with treatment time. Dental cast measurements were made for arch width and arch length. Treatment duration was broken into near-equal time segments and compared. Results showed that about 50% of the total expansion achieved occurred within about the first 100 days. Forty percent of the total amount of expansion occurred during the next 200 days, with only about 10% of the total expansion occurring after the first 300 days. It is unnecessary to have the appliance in place for longer than 300 days. The percentage of expansion that occurred at each time segment was not related to whether the patient had concomitant maxillary expansion.