Morfologia dentofacial e características oclusais dos índios Arara: revisitando o papel da hereditariedade e da dieta na etiologia da má oclusão

• Ano de defesa: 2010
• Autor(a) principal: Normando, Antonio David Corrêa
• Orientador(a): Quintão, Cátia Cardoso Abdo
• Banca de defesa: Pordeus, Isabela Almeida , Guerreiro, João Farias , Faber, Jorge do Nascimento , Almeida, Marco Antonio de Oliveira , Ursi, Weber José da Silva
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Odontologia
• Departamento: Centro Biomédico::Faculdade de Odontologia
• País: BR
• Palavras-chave em Português: Má oclusão; Epidemiologia; Etiologia; Desgaste dentário; Indígenas; Maloclusão - Epidemiologia; Maloclusão - Etiologia; Maloclusão - Aspectos genéticos; Índios Arara
• Palavras-chave em Inglês: Dental malocclusion; Epidemiology; Etiology; Tooth wear; Indigenous
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA::ORTODONTIA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/13974

The influence of diet and genetics on dentofacial features was examined through the analysis of two split indigenous Amazon populations originated by a process of a linear fission. The Arara-Iriri indigenous are descendants of a single couple who were expelled from a larger village (Arara-Laranjal). In the resultant new village, the initial expansion occurred through the mating of closely related people, causing a high coefficient of inbreeding (F=0.25, p<0.001). The epidemiology of malocclusion and facial characteristics were analyzed in individuals aged from 2 to 22 years, from the Arara-Iriri (n=46) and Arara-Laranjal (n=130) villages. The biometric study of the dentition and face was performed in the permanent dentition of the indigenous without tooth loss (n=55) by facial photogrammetry and dental casts analysis. Tooth wear was examined in 126 individuals in the permanent dentition through multiple regression analysis. Findings pointed out a significant determination of age on tooth wear (R2=87.6, p<0.0001), which was similar between the villages (R2=0.027, p=0.0935). However, we found marked differences in the dentofacial morphology. The indigenous of the Iriri village presented a more vertical face (dolichofacial) compared to the people of the original village, predominantly braquifacial. This clinical data was corroborated by facial photogrammetry. A sagitally normal face was observed in 97.7% of the Laranjal village, while convex (26.1%, RR=16.96) and concave faces (15.2%, RR=19.78) were significantly more prevalent in the Iriri village (p<0.001). Biprotrusion, with consequent reduction of nasolabial angle, was a common feature among the Arara indigenous, but its occurrence in the Iriri village was higher (RP=1.52, p=0.0002). The prevalence of malocclusion was significantly higher in the Iriri population (RP=1.75, p=0.0007). While the majority of the population (83.8%) in the Laranjal village presented a normal Class I relationship, in the Iriri village 34.6% were Class III (RP=6.01, p<0.001) and 21.7% were class II (RP=2.02, p=0.05). No case of crowding and overbite was observed in the Iriri village, however the relative risk was 2.64 times greater for anterior open bite (p=0.003), 2.83 for anterior crossbite (p<0.001), 3.93 for increased overjet (p=0.03), and 4.71 times (p=0.02) for posterior crossbite. We observed a high prevalence of tooth loss, with no significant difference between the villages (RP=1.46, p=0.11). The dental cast analysis revealed larger incisors combined to smaller cuspids and bicuspids in the Iriri sample, causing an overall similarity in the total tooth size between the villages, which associated to larger dental arch dimensions, explained a decreased incisor irregularity in the Iriri indigenous. These findings mitigates the influence of tooth wear, a direct evidence of what an individual ate in the past, on dentofacial development and emphasize the role of heredity, through inbreeding, in the etiology of abnormal variation of dental occlusion and facial morphology of current human populations.