Microscopic evaluation of induced tooth movement after subluxation trauma: an experimental study in rats

OBJECTIVE: The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation). METHODS: Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n = 5), according to the combination of variables: Group 1 - control (neither trauma nor ITM); Group 2 - ITM; Groups 3, 4, 5 and 6 - dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. RESULTS: In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2. CONCLUSION: There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma. .

OBJETIVO: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). MÉTODOS: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 - controle (sem trauma e sem MDI); Grupo 2 - MDI; Grupos 3, 4, 5 e 6 - grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 - os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. RESULTADOS: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. CONCLUSÃO: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação. .

Effect of administration of thiazide and/or propranolol on mandibular alveolar bone in rats. an attempt for the possible mechanisms

Bone mass is maintained constant through the interplay of bone resorption by osteoclasts and bone formation by osteoblasts. Osteoporosis is the most frequent degenerative disease in developed countries. Short-term increases in dietary salt result in increased urinary calcium loss, which suggests that over time, salt intake may cause bone loss. Several studies have reported increased bone density and decreased fracture risk in patients treated with thiazides. Recently, leptin has emerged as a potential candidate for protective effects of fat on bone mass. Furthermore, animal data suggests that bone formation is under beta-adrenergic control and that p-blockers stimulate bone formation and/ or inhibit bone resorption. Moreover, propranolol-treated mice established a direct link between leptin antiosteogenic function and sympathetic activity. The objective of this study was to determine the effects of sodium chloride [NaCl] intake, alone or combined with thiazide and/or propranolol on bone formation and declear their possible mechanisms of action. In this study, treatment of rats with NaCl solution with either thiazide or propranolol orally for 12 weeks produced significant increase in serum calcium with decrease in urine calcium but produced significant decrease in serum phosphorus with increase in urine phosphorus compared with salt treated rats. Administration of salt with thiazide produced non-significant decrease of serum alkaline phosphatase and non-significant increase of serum leptin, while administration of salt with propranolol produced significant decrease of serum alkaline phosphatase and serum leptin compared with salt treated rats. These results were supported with histological and histochemical examinations' where administration of thiazide or propranolol with salt produced increasing of bone mass, decreasing in bone marrow spaces and produced strong or moderate reaction for alkaline phosphatase, respectively in comparison with salt treated rats. In conclusion, in the light of these results, we could recommend double bladed weapon medication [thiazide and/or propranolol] for many elderly patients with high blood pressure to drive a double benefits i.e., lowering the elevated blood pressure, prevention and/or attenuation of bone loss and osteoporosis which may constitute a potential intervention therapy to prevent alveolar bone loss in periodontal disease

Aspectos clínicos e histológicos da anquilose múltipla de molares decíduos: relato de caso / Clinical and histological aspects of multiple ankylosis of primary molars: case report

A anquilose dentoalveolar de molares decíduos consiste na fusão anatômica do cemento e/ou dentina ao osso alveolar, cujo exame clínico, na maioria dos casos, é o principal recurso para o diagnóstico. Quanto menor o grau de severidade da infra-oclusão decorrente da anquilose e quanto mais precocemente esta for diagnosticada, menores serão as seqüelas desta anomalia. Atualmente, a conduta preconizada é o controle clínico e radiográfico dos casos de anquilose leve e moderada e exodontia nos casos de anquilose severa, considerando que as características individuais do paciente são importantes na decisão do tratamento. Este trabalho tem como objetivo discutir os principais aspectos clínicos e histológicos desta anomalia e apresentar um caso clínico de anquilose múltipla, com acompanhamento de cinco anos, abordando uma prosta de tratamento