Marcus Vinicius Neiva Nunes do Rego

Estudo longitudinal da relação entre o crescimento mandibular e o crescimento estatural em indivíduos com Classe II esquelética

The height growth of children and teenagers, as well as its relationship with the rate of craniofacial growth, are of large interest to the orthodontist, since the indication of a therapy to control jaw development is based on the study of the skeletal age of the patient and subsequent somatic maturation. Therefore, this study aimed at evaluating the correlation between height growth and mandibular growth of 30 subjects presenting with skeletal Class II, with no orthodontic treatment, which were longitudinally followed-up through the Burlington Growth Study of Canada. The serial records were obtained at 6, 9, 12, 14 and 16 years of chronological age and comprised lateral cephalograms, clinical records and personal information. The results indicated that the height growth spurt, as well as the largest mean increase in the mandibular measurements, occurred from 9 to 12 years of age for the females and from 12 to 14 years of age for the males. Moreover, it was also observed that, among all study measurements, the rate of increase of the mandibular length demonstrated the strongest correlation with the mean rate of height growth of these individuals, specially for the males during their growth spurt (r=0,758).

Estudo cefalométrico do tratamento precoce da má oclusão de Classe II, 1ª divisão, com o aparelho Herbst: alterações esqueléticas sagitais

AIM: the present study aimed at evaluating the sagittal skeletal alterations after Herbst appliance treatment. METHODS: the sample was comprised by in 22 subjects with Class II division 1 malocclusion, being 11 males and 11 females, with a mean age of 9.01 years (±06 months), who presented Class II facial pattern, mandibular deficiency and Class II skeletal pattern (ANB>5o and Co-Gn - Co-Sn <20mm) and were consecutively treated with the Herbst appliance for a mean period of 12 months. All subjects were on the intermediate period of the mixed dentition and on the pre-pubertal stage. Evaluation was performed on lateral cephalograms taken in three different moments: T1) initial, T2) soon after removal of the appliance, T3) 2 years after treatment completion. The control group was composed by 105 subjects with skeletal Class II malocclusion not submitted to orthodontic treatment, matched as to the bone and chronological ages of the study group. Statistical analysis was performed by means of Analysis of Variance (ANOVA), complemented by the Tukey test for multiple comparisons and the Students t test, at a significance level of 5%. RESULTS AND CONCLUSION: the results revealed an not significant effect of restriction of the maxillary growth, stimulation of the mandibular growth and forward positioning of the mandible, which contributed to a significant improvement in the jaw relationship. These sagittal skeletal alterations accounted for about 41% of the correction of the Class II molar relationship and 65% of the overjet correction. At 2 years after removal of the appliance there was a tendency towards a reduction in the magnitude of the alterations achieved; however, significant improvements in the jaw relationship, overjet and molar relationship were noticeable.

Avaliação da superfície de braquetes de titânio após a aplicação de fluoreto de sódio

AIM: to assess and compare the effects of fluoride (NaF 1.23%) on titanium and stainless steel brackets. METHODS: Fifteen titanium brackets, divided in 3 groups were used: A) control group (no treatment on its surface), B) brackets immersed in NaF (60 seconds) and washed with distilled water (30 seconds), C) brackets with similar treatment to group B and submitted to brushing (15 seconds). Fifteen stainless steel brackets were used for comparative effects, divided in 3 groups, and submitted to the same described procedures. All brackets were evaluated by macroscopic (visual appearence) and scanning microscopy (Philips, model XL 30), before and after the procedures. RESULTS: titanium brackets submitted to fluoride (NaF), groups B and C, presented discoloration (matte gray color) when compared to group A. Stainless steel brackets showed no color alteration. CONCLUSION: titanium and stainless steel brackets showed no change in surface roughness or chemical components when immersed in sodium fluoride solution.

Perception of changes in soft-tissue profile after Herbst appliance treatment of Class II Division 1 malocclusion

Introduction: In this study, we sought to assess the perception of changes in soft‐tissue profile after Herbst appliance treatment by comparing facial profile silhouettes before treatment, immediately after treatment, and 2 years after treatment, as examined by orthodontists, general dentists, and laypersons. Methods: The sample comprised 21 patients (mean age, 9.5 ± 0.5 years), who were treated with the Herbst appliance for a mean period of 12 (±1.1) months. Three lateral cephalograms were obtained at different times: baseline, immediately after removal of the Herbst appliance, and 2 years after removal of the appliance. The 63 resulting profile silhouettes were evaluated by 120 examiners divided into 3 groups: orthodontists, general dentists, and laypersons. The examiners were instructed to choose their preferred profile and note how much change they perceived across profiles using a visual analog scale. Results: All groups of examiners preferred the posttreatment profiles. However, on quantitative assessment, the magnitudes of changes in the profile were found to be variable and rather small, with laypersons quantifying the greatest magnitude of change. Conclusions: Early Herbst appliance treatment produced positive changes in the facial profile that were visually appreciable both immediately after removal of the appliance and 2 years after treatment. HighlightsEarly treatment with the Herbst appliance promoted positive changes on the profile.These changes were noticeable by orthodontists, general dentists, and laypersons.The laypersons group quantified the greatest changes in the profiles.