Correlation of the cranial base angle and its components with other dental/skeletal variables and treatment time

Many authors have studied the correlation of cranial base flexure and the degree of mandibular prognathism and classification of malocclusion. This indicates that the cranial base flexure may or may not have an effect on the degree of mandibular prognathism and classification of malocclusion. This study evaluates the correlation of the pretreatment cranial base angle and its component parts to other dental and skeletal cephalometric variables as well as treatment time. The sample consisted of 99 Angle Class II and Class I malocclusions treated in the mixed dentition with cervical headgear and incisor bite plane. Thirty of the patients required full appliance treatment. Treatment duration averaged 4.3 years (SD, 1.5 years). Only the starting cephalograms were used to acquire linear, proportional, and angular cranial base dimensions using Ba-S-N (total cranial base), Ba-S/FH (posterior cranial base), and SN/FH (anterior cranial base). Pearson product moment correlation coefficients were computed and used to assess the association of the following skeletal and dental variables: N-Pg/FH, MP/FH, Y-axis/FH, U1/L1, L1/MP, A-NPg mm, A-Perp, B-Perp, and treatment time with the cranial base measurements. Significance was determined only when the confidence level was P < .05. Although there was no significant correlation of BaSN or SN/FH with NPg, the angular BaS/FH, linear BaS mm, and proportional length of BaS %BaN were all statistically negatively correlated to the facial angle. This indicates that the posterior cranial base leg is the controlling factor in relating the cranial base to mandibular prognathism.     

Influence of the use of Er:YAG laser for cavity preparation and surface treatment in microleakage of resin-modified glass ionomer restorations

This study quantitatively assessed the amount of microleakage on Class V cavities prepared by Er:YAG laser and high-speed handpiece, varying the surface treatment and restoring with a resin-modified glass ionomer cement. Fifty cavities were prepared using either an Er:YAG laser device or a carbide bur at high speed. The surface treatment was performed as follows: Er:YAG laser irradiation (G1); 40% polyacrylic acid (G2); laser + acid (G3); finishing with low speed + laser + acid (G4); conventional bur preparation + acid (G5-control). The samples were restored with Fuji II LC, thermocycled, isolated and immersed in a 50% AgNO3 solution. The restorations were serially sectioned and the extent of dye penetration was measured in milimeters using specific computer software. Data were analyzed by two-way ANOVA and Tukey test. The lowest degree of microleakage was observed for G5, which was statistically similar (p>0.05) to G4 but different (p<0.05) from all the other experiental groups. Lesser microleakage was observed at the occlusal margins than at the cervical margins (p<0.05). It may be concluded that the use of Er:YAG laser for cavity preparation and surface treatment negatively affected the marginal sealing of resin-modified glass ionomer restorations.     

The impact of third molar symptoms, pain, and swelling on oral health-related quality of life.

PURPOSE: This study was designed to assess the impact of "pain and swelling" associated with third molars on patients' quality of life before surgery. PATIENTS AND METHODS: The data for these analyses were obtained from a larger ongoing study designed to examine the surgical and medical management of problems associated with third molars. Data from 480 patients with 4 third molars scheduled for removal were used in the analysis. Questionnaires administered presurgery assessed patients' medical and dental history, their reasons for seeking third molar removal, and sociodemographic characteristics. Adverse impacts on oral health-related quality of life were measured using the 14-item Oral Health Impact Profile (OHIP) questionnaire. The primary outcome variable was the percentage of people reporting 1 or more of the 12 non-pain-specific OHIP items "fairly often" or "very often" during the 3 months before enrollment. RESULTS: One third (178 of 480) of patients said they were seeking third molar surgery because of current or previous symptoms of pain/swelling, and 17% reported 1 or more of the 12 non-pain-specific OHIP items. In the multivariate logistic regression model, the odds of one or more impacts was greater for people who presented because of symptoms (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.7 to 4.8), who were aged 25 years or more (OR, 1.9; 95% CI, 1.1-3.3), and who had a self-reported history of tooth loss due to pathology or trauma (OR, 2.9; 95% CI, 1.9 to 5.5). CONCLUSIONS: Adverse impacts on quality of life occurred for 1 in 8 patients seeking third molar surgery, and the odds increased 3-fold for patients who had experienced pain/swelling compared with those who were asymptomatic.