Effect of photobiomodulation on the stability and displacement of orthodontic mini-implants submitted to immediate and delayed loading: a clinical study.

The aim of this study was to evaluate the effect of photobiomodulation (PBM) on the stability and displacement of orthodontic mini-implants (MIs) submitted to loading. Forty-eight and 35 mini-implants (1.5 × 8 × 1 mm) were assessed for stability and displacement, respectively (19 patients). MIs were allocated according to the intervention in 1-PBM + immediate loading (IL), 2-PBM + delayed loading (DL) (four weeks after implantation), 3-IL only, and 4-DL only. PBM (Therapy XT, DCM) was implemented using a red emission (660 nm, 4 J/cm2, 0.1 W, 20 s) immediately after implantation (day 0) and infrared emissions (808 nm; 8 J/cm2, 0.1 W, 40 s) in the following appointments every 48-72 h during two weeks (days 2, 4, 7, 9, 11, and 14). Loading of 150 gF was applied during three months for all MIs. The stability was assessed by resonance frequency analysis (Osstell ISQ), and images from Cone beam computed tomography were evaluated to determine the amount of the displacement of the MI's head. MIs from the PBM groups presented lower loss of stability (P = 0.0372). When the analysis considered the loading protocol as an additional variable, group two showed the lowest loss of stability, being significantly different from groups that did not receive PBM (P = 0.0161). There was no difference between groups two and four during the period without loading (P > 0.05). DL groups presented lower loss when the effective period of loading was assessed, independently of the application of PBM (P < 0.0001). All groups showed displacement of the MIs head without significant differences (P > 0.05). DL potentiated the effect of PBM, decreasing the loss of stability.

Association between polymorphisms in genes encoding estrogen receptors (ESR1 and ESR2) and excreted bisphenol A levels after orthodontic bracket bonding: a preliminary study.

BACKGROUND: Bisphenol A (BPA) is released from orthodontic composites used for bracket bonding. Genetic variations could modify the metabolism of this chemical within the organism. Considering that free BPA binds to estrogen receptors causing harmful effects to health, the present in vivo study aimed to evaluate the association between genetic polymorphisms in genes encoding estrogen receptors (ESR1 and ESR2) and excreted BPA levels in orthodontic patients. METHODS: Quantification of BPA levels in the urine of 16 patients was performed in a gas chromatograph mass spectrometer before (T0), at 24 h (T1), and 1 week (T2) after bracket bonding. DNA was extracted from saliva, and one genetic polymorphism in ESR1 (rs2234693) and two in ESR2 (rs4986938 and rs1256049) were analyzed by real-time PCR. Increases in BPA levels in the urine at T1 and T2 were grouped according to the genotype, and mean differences were compared by unpaired T test or Mann-Whitney test according to the normality of the data. The established alpha was 5%. RESULTS: BPA levels increased significantly at T1 and T2. There were no statistically significant differences in the increases in BPA levels according to the genotype for any genetic polymorphism (P > 0.05), at neither 24 h nor 1 week after bracket bonding. CONCLUSIONS: The results suggested that there are no association between excreted BPA levels after bracket bonding and the evaluated genetic polymorphisms in ESR1 and ESR2. Further research should be performed in order to confirm these results.

Predictors of uvulopalatopharyngoplasty success in the treatment of obstructive sleep apnea syndrome.

OBJECTIVE: Uvulopalatopharyngoplasty (UPPP) has been described as an option for treating obstructive sleep apnea syndrome (OSAS), with variable success rates. The main purpose of our study was to correlate UPPP success to craniofacial bony structure and orofacial muscles function. METHODS: Clinical variables, including body mass index (BMI), age, and preoperative apnea-hypopnea index (AHI); cephalometric measurements of the craniofacial region and hyoid bone position; and muscle function variables including clinical protocol and tongue strength measures were evaluated in 54 patients who underwent UPPP in the last 7years. The measurements were related to the success or failure of UPPP based on the results of preoperative and postoperative polysomnography (PSG). RESULTS: The variables BMI, preoperative AHI, and cephalometric measurements showed no influence on surgical success. The clinical muscle protocol also was similar between groups. However, the muscle strength of the anterior portion of the tongue was significantly greater in the group that showed surgical success compared to those with surgical failure. CONCLUSION: OSAS is a multifactorial disease and diagnostic symptom assessments should be individualized. In addition, special attention should be given to functional muscle alterations of the airways, as they might influence the evolution of the disease.

Skeletal and occlusal characteristics in mouth-breathing pre-school children.

This study verified the influence of chronic mouth breathing on dentofacial growth and developmental in pre-school children. The study evaluated 73 children, both sexes, ranging from 3 to 6 years of age. After the otorhinolaryngological breathing diagnosis, 44 mouth-breathing children and 29 nasal-breathing children were compared according to facial and occlusal characteristics. The skeletal pattern measurements SN.GoGn, BaN.PtGn, PP.PM, Ar-Go, S-Go indicated a tendency to mouth-breathing children presenting a dolicofacial pattern. According to occlusal characteristics, only the intermolar distance showed a significant correlation with a narrow maxillary arch in mouth-breathing subjects. Based on the results of this study, mouth-breathing can influence craniofacial and occlusal development early in childhood.

Muscular, functional and orthodontic changes in pre school children with enlarged adenoids and tonsils.

INTRODUCTION: Hypertrophy of the adenoids and palatine tonsils is the second most frequent cause of upper respiratory obstruction and, consequently, mouth breathing in children. Prolonged mouth breathing leads to muscular and postural alterations which, in turn, cause dentoskeletal changes. OBJECTIVE: The aim of this study was to determine muscular, functional and dentoskeletal alterations in children aged 3-6 years. MATERIALS AND METHODS: Seventy-three children, including 44 with tonsil hypertrophy and 29 controls, were submitted to otorhinolaryngologic, speech pathologic and orthodontic assessment. RESULTS: Otorhinolaryngologic evaluation revealed a higher incidence of nasal obstruction, snoring, mouth breathing, apneas, nocturnal hypersalivation, itchy nose, repeated tonsillitis and bruxism in children with tonsils hypertrophy. Speech pathologic assessment showed a higher incidence of open lip and lower tongue position, and of hypotonia of the upper and lower lips, tongue and buccinator muscle in these children, accompanied by important impairment in mastication and deglutition. Orthodontic evaluation demonstrated a higher incidence of lower mandible position in relation to the cranial base, a reduction in lower posterior facial height, transverse atresia of the palate, and a dolicofacial pattern. CONCLUSION: Postural and functional alterations anticipate dentoskeletal changes, except for the facial pattern. Postural alterations and the skeletal pattern seem to play an important role in infant dentofacial growth.