Sandra Anić Milošević

Maximum voluntary molar bite force in subjects with normal occlusion

The aims of this investigation were to determine whether stabilization of maximum voluntary bite force (MVBF) occurs between 15 and 18 years of age in subjects with a normal occlusion, and to assess the influence of gender, body mass index (BMI), morphological occlusion, and jaw function measured by the number of occlusal contacts, overjet, overbite, maximal mouth opening, mandibular deflection during opening, sagittal slide between the retruded contact position and the intercuspal position, and number of dental restorations. The sample comprised 60 Caucasian subjects aged 15 (15 males and 15 females) and 18 (14 males and 16 females) years with a neutral occlusion, balanced facial profile, and absence of a previous orthodontic history. Bite force measurements were undertaken using a portable occlusal force gauge on both the left and the right sides of the jaw in the first molar region during maximal clenching. Two independent samples t-tests and multiple regression were used for statistical analysis. MVBFs were age and gender related (P<0.05). Males showed a significant increase in bite force between 15 and 18 years of age (P=0.002), but gender differences were significant only in the 18-year-olds (P=0.003). In subjects with a neutral occlusion, MVBF could best be predicted using multiple regression from age and gender. The regression model accounted for 31.3 percent of the variance in MVBF (P=0.031), with gender contributing 17.9 percent and age 7.9 percent. Morphological occlusion, jaw function, and BMI explained the remaining 5.5 percent of variance. While controlling for all other parameters, the independent contribution of gender to the prediction of MVBF was 16.2 percent, age 6 percent, number of occlusal contacts 3.2 percent, and BMI 1.3 percent.

Analysis of the soft tissue facial profile of Croatians using of linear measurements.

One hundred and ten subjects (52 males and 58 females) between 23-28 years of age with dental Class I occlusal relationship, good soft tissue profile, and Caucasian ethnicity were selected from the population of dental students at the University of Zagreb, Croatia. The soft tissue facial profiles were digitally analyzed using linear (11 vertical and 14 horizontal) measurements made with standardized photographic records, taken in natural head position, to determine average soft tissue facial profile for males and females. The application of Student t-test showed gender dimorphism in most parameters of the labial, nasal. and chin areas. Almost all vertical variables were larger in the males, except the length of the nasal tip, which was larger in females. In the height of the vermilion, no gender dimorphism was observed. The females exhibited shallower labial sulci than the males and their chins were at least as prominent as those of the males. This study showed that male chins are not absolutely more prominent than female chins, but only appear to be such because their labial sulci are deeper.

Clinical and microbiological parameters in patients with self-ligating and conventional brackets during early phase of orthodontic treatment.

OBJECTIVE To determine the effect of different bracket designs (conventional brackets and self-ligating brackets) on periodontal clinical parameters and periodontal pathogens in subgingival plaque. MATERIAL AND METHODS The following inclusion criteria were used: requirement of orthodontic treatment plan starting with alignment and leveling, good general health, healthy periodontium, no antibiotic therapy in the previous 6 months before the beginning of the study, and no smoking. The study sample totaled 38 patients (13 male, 25 female; mean age, 14.6 ± 2.0 years). Patients were divided into two groups with random distribution of brackets. Recording of clinical parameters was done before the placement of the orthodontic appliance (T0) and at 6 weeks (T1), 12 weeks (T2), and 18 weeks (T3) after full bonding of orthodontic appliances. Periodontal pathogens of subgingival microflora were detected at T3 using a commercially available polymerase chain reaction test (micro-Dent test) that contains probes for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola. RESULTS There was a statistically significant higher prevalence of A actinomycetemcomitans in patients with conventional brackets than in patients with self-ligating brackets, but there was no statistically significant difference for other putative periodontal pathogens. The two different types of brackets did not show statistically significant differences in periodontal clinical parameters. CONCLUSION Bracket design does not seem to have a strong influence on periodontal clinical parameters and periodontal pathogens in subgingival plaque. The correlation between some periodontal pathogens and clinical periodontal parameters was weak.

Changes of bite force and occlusal contacts in the retention phase of orthodontic treatment: A controlled clinical trial

Introduction: We aimed to determine whether appliance type affects changes in maximum voluntary bite force (MVBF) and the number of occlusal contacts (NOC) during retention, controlling for sex, age, and body mass index. Methods: The sample comprised 176 examinees (70 male, 106 female) aged 14 to 20 years: 30 had maxillary and mandibular Essix retainers, 30 had wrap‐around retainers, and 30 had a combination of fixed mandibular canine‐to‐canine retainers bonded on each tooth separately (double twisted, 0.254 mm in diameter, stainless steel ligature wire) and Essix retainer in the maxillary arch; 86 with normal occlusion were not treated. MVBF and the NOC were measured immediately after removal of preadjusted edgewise appliances (Roth prescription), 6 weeks after that, and after the next 4 weeks. Results: Increases in MVBF and the NOC were demonstrated, but subjects with 2 Essix retainers showed lower values than did the others. Changes were related to type of appliance, sex, and age (P <0.05) but not to body mass index. The increase in NOC occurred faster than the increase of MVBF, more and sooner with the wrap‐around retainer and in male subjects than with the Essix and in female subjects. MVBF and NOC nearly reached the values of the control subjects. Conclusions: Settling of the occlusion depends on appliance type: it takes longer in female patients and with Essix in both dental arches than with the other tested appliances. HighlightsMaximum voluntary bite force and number of occlusal contacts increase during the first 10 weeks of retention.Settling occurs sooner with the wrap‐around retainer and in males than with the Essix and in females.Body mass index is not related to changes in maximum voluntary bite force and number of occlusal contacts.