Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-04T17:39:23Z No. of bitstreams: 1 MARINA_CAVALLET_DE_ABREU_DIS.pdf: 5939437 bytes, checksum: 512afdadf2d38aff33e82d116c75c55d (MD5) / Rejected by Sheila Dias (sheila.dias@pucrs.br), reason: Devolvido devido ? falta da capa institucional no arquivo em PDF. on 2018-06-14T13:39:17Z (GMT) / Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-26T18:07:27Z No. of bitstreams: 1 MARINA_CAVALLET_DE_ABREU_DIS.pdf: 3243819 bytes, checksum: b6fdcf46eabe33351202bd83deb2e3df (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-02T17:31:50Z (GMT) No. of bitstreams: 1 MARINA_CAVALLET_DE_ABREU_DIS.pdf: 3243819 bytes, checksum: b6fdcf46eabe33351202bd83deb2e3df (MD5) / Made available in DSpace on 2018-07-02T17:37:46Z (GMT). No. of bitstreams: 1 MARINA_CAVALLET_DE_ABREU_DIS.pdf: 3243819 bytes, checksum: b6fdcf46eabe33351202bd83deb2e3df (MD5) Previous issue date: 2018-01-24 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / In preventive and interceptive orthodontics, the use of mandibular fixed lingual arch is a commonly accepted procedure to maintain arch perimeter by preventing mesial tipping or drifting of the mandibular molars. Despite its widespread use, comparatively little is known concerning the efficiency of a lower lingual holding arch as a space holding device and its effect on the dimensions of the lower arch. Objectives: To quantify the arch dimensional changes that occur during the lingual arch use. Digital models were used to evaluate sagittal and transversal changes in the lower arch. Materials and Methods: The sample consisted of 38 patients (20 boys, 18 girls), with a mean age of 9.2 years (range, 7-12.2 years). For the control group, a retrospective sample of 21 patients (11 boys, 10 girls) with a mean age of 9.4 years (range, 7.8 - 12.3 years) was selected. Patients were classified according to growth pattern, for SN.GoGn ? 32? (Horizontal) and for SN.GoGn> 32? (Verticals). A total of 118 dental cats were scanned (3Shape R700, Copenhagen, Denmark). The OrthoAnalyzer software (3Shape, Copenhagen, Denmark) was used to evaluate the files. The independent t-test was used to evaluate the experimental group and control group. And the paired t-test was used for a comparison between groups. Results: In the lingual arch group, the arch length was not significant (p >0,05). The intermolar width significantly increase (p <0.001). Buccolingual inclination of the lower incisors was statistically significant (p <0.001). The lingual arch was more effective for preserving the arch length in vertical patients (p< 0,001) and buccolingual inclination of the lower incisors was statistically significant for these patients (p <0.001) Conclusions: The lingual arch is good appliance for preserving arch length, mainly in vertical patients, but with a potential for buccolingual inclination of the lower incisors. The intermolar width, and buccolingual inclination of the molars and lower incisors significantly increased. / O aparelho arco lingual ? indicado para o tratamento na fase de denti??o mista com o intuito de preservar o comprimento de arco em casos de perda precoce de dentes dec?duos, impedindo a migra??o mesial do primeiro molar permanente. Embora a efetividade do uso do arco lingual seja universalmente aceita, o seu efeito na mudan?a da posi??o sagital e transversal dos molares e incisivos em pacientes em crescimento precisa ser melhor documentado. Objetivos: Avaliar em modelos digitais os efeitos do tratamento com arco lingual nos molares e incisivos permanentes em pacientes com diferentes tipos faciais. Materiais e M?todos: A amostra experimental consistiu em 38 pacientes (20 meninos, 18 meninas), com m?dia de idade de 9 anos e 2 meses (varia??o, 7-12,2 anos). Para o grupo controle, foi selecionada uma amostra retrospectiva de 21 pacientes (11 meninos, 10 meninas), com m?dia de idade de 9 anos e 4 meses (varia??o, 7,8 ? 12,3 anos). Os pacientes foram classificados de acordo com o padr?o de crescimento, para SN.GoGn ? 32? (Horizontais) e para SN.GoGn > 32? (Verticais). Um total de 118 modelos de estudo, foram escaneados (3Shape R700; Copenhagen, Denmark), e analisados no software OrthoAnalyzer (3Shape, Copenhagen, Denmark). O Teste t para amostras independentes foi utilizado para avaliar o grupo experimental e grupo controle. E o Teste t pareado, foi utilizado para a compara??o entre os grupos. Resultados: No grupo arco lingual o comprimento de arco n?o apresentou varia??o estatisticamente significativa (p >0,05). Ocorreu aumento estatisticamente significativo da dist?ncia intermolares (p<0,001). Ocorreu inclina??o para vestibular, estatisticamente significativa, dos incisivos inferiores (p < 0,001). O arco lingual foi mais efetivo na preserva??o do comprimento do arco para pacientes verticais (p< 0,001) e ocorreu inclina??o vestibular dos incisivos inferiores estatisticamente significativa para esses pacientes (p < 0,001). Conclus?es: O uso do arco lingual preservou o comprimento de arco, principalmente nos pacientes verticais, por?m com maior potencial de inclina??o vestibular dos incisivos inferiores nesses pacientes. O aparelho causou aumento significativo da dist?ncia intermolares, da inclina??o vestibular de incisivos e molares inferiores.