Applied mechanics of the Puricelli osteotomy: a linear elastic analysis with the finite element method

<p>Abstract</p> <p>Background</p> <p>Surgical orthopedic treatment of the mandible depends on the development of techniques resulting in adequate healing processes. In a new technical and conceptual alternative recently introduced by Puricelli, osteotomy is performed in a more distal region, next to the mental foramen. The method results in an increased area of bone contact, resulting in larger sliding rates among bone segments. This work aimed to investigate the mechanical stability of the Puricelli osteotomy design.</p> <p>Methods</p> <p>Laboratory tests complied with an Applied Mechanics protocol, in which results from the Control group (without osteotomy) were compared with those from Test I (Obwegeser-Dal Pont osteotomy) and Test II (Puricelli osteotomy) groups. Mandible edentulous prototypes were scanned using computerized tomography, and digitalized images were used to build voxel-based finite element models. A new code was developed for solving the voxel-based finite elements equations, using a reconditioned conjugate gradients iterative solver. The Magnitude of Displacement and von Mises equivalent stress fields were compared among the three groups.</p> <p>Results</p> <p>In Test Group I, maximum stress was seen in the region of the rigid internal fixation plate, with value greater than those of Test II and Control groups. In Test Group II, maximum stress was in the same region as in Control group, but was lower. The results of this comparative study using the Finite Element Analysis suggest that Puricelli osteotomy presents better mechanical stability than the original Obwegeser-Dal Pont technique. The increased area of the proximal segment and consequent decrease of the size of lever arm applied to the mandible in the modified technique yielded lower stress values, and consequently greater stability of the bone segments.</p> <p>Conclusion</p> <p>This work showed that Puricelli osteotomy of the mandible results in greater mechanical stability when compared to the original technique introduced by Obwegeser-Dal Pont. The increased area of the proximal segment and consequent decrease of the size of lever arm applied to the mandible in the modified technique yield lower stress values and displacements, and consequently greater stability of the bone segments.</p

A Síndrome de Marfan e seus aspectos odontológicos: revisão da literatura

A síndrome de Marfan é uma doença do tecido conjuntivo, de caráter hereditário, com grande variabilidade de expressão clínica. Afeta fundamentalmente os sistemas esquelético, cardiovascular e ocular. Sua etiologia está relacionada a mutações no gene da fibrilina-1 (FBN1),* localizado no cromossomo 15 (15q21.1). As alterações dento-faciais presentes na síndrome, além de outras características relacionadas ao sistema estomatognático, tornam importantes o reconhecimento desta condição e o adequado manejo do paciente pelo profissional da Odontologia. O objetivo deste artigo é revisar a literatura que relaciona a SM à Odontologia

Proliferação in vitro de células tronco da medula óssea humana sobre discos de cimento de αlfa-trifosfato de cálcio e titânio

Objectives: to evaluate human bone marrow stem cells (HBMSC) cultured on α -tricalcium phosphate cement (α -TCP) and titanium (Ti) discs, as well as the osteoconductive properties of these biomaterials. Methods: discs of α -TCP and commercially pure Ti were manufactured and placed on polyethylene plates. Cells were cultured according to the following: group I – control (no discs); group II – α-TCP discs; group III – Ti discs. Propidium iodide staining was used to assess cell proliferation. Cells cultures were analyzed at 3, 7, 14 and 21 days. Results: Proliferation occurred in both biomaterials. At 3 days, greater cell proliferation was seen in group II than group III (p=0.01). Differences were not significant on the other time periods. Morphologic analysis showed circular morphology in group I, compatible with osteogenic cell lineage. Conclusions: both biomaterials were osteoconductive but not osteoinductive. This did not affect the initial stages of osteogenesis.Objetivos: avaliar culturas de células tronco da medula óssea humana (HBMSC) sobre discos de cimento de α -trifosfato de cálcio (α -TCP) e titânio (Ti), bem como a propriedade de osteocondução destes biomateriais. Métodos: discos de α -TCP e Ti comercialmente puro foram confeccionados e colocados em placas de polietileno. As culturas celulares foram distribuídas da seguinte forma: grupo I – controle (sem discos); grupo II – discos de α -TCP; grupo III – discos de Ti. Foi utilizado iodeto de propídio para possibilitar a constatação da proliferação celular. As culturas celulares foram avaliadas em 3, 7, 14 e 21 dias. Resultados: a proliferação das HBMSC ocorreu em ambos os biomateriais. No terceiro dia, uma maior proliferação celular foi constatada no grupo II e-m relação ao grupo III (p=0,01). Nos demais períodos não foram constatadas diferenças significativas. A análise morfológica demonstrou células com morfologia circular no grupo I, compatíveis com linhagem osteogênica. Conclusões: ambos biomateriais mostraram-se osteocondutores, mas não osteoindutores, não interferindo nos estágios iniciais da osteogênese

Dental aspects of Marfan syndrome : case report and review of the literature

A síndrome de Marfan é uma doença do tecido conjuntivo, de caráter hereditário, com grande variabilidade de expressão clínica. Afeta fundamentalmente os sistemas esquelético, cardiovascular e ocular. Sua etiologia está relacionada a mutações no gene da fi brilina-1 (FBN1),* localizado no cromossomo 15 (15q21.1). As alterações dento-faciais presentes na síndrome, além de outras características relacionadas ao sistema estomatognático, tornam importantes o reconhecimento desta condição e o adequado manejo do paciente pelo profissional da Odontologia. O objetivo deste artigo é revisar a literatura que relaciona a SM à Odontologia.The Marfan syndrome is an inheritable connec tive tissue disease, with variable clinical expression. The disease affects specially the skeletal, cardiovascular and ocular systems. Mutations in the gene coding for fi brillin on chromosome 15 (FBN1) are known to cause Marfan syndrome. The dentofacial abnormalities present on the disease, as well as other stomatognathic characteristics, make the recognizing and correct managing of these patients important. This paper resumes some of the most important aspects about SM related to Dentistry

Dental aspects of Marfan syndrome : case report and review of the literature

A síndrome de Marfan é uma doença do tecido conjuntivo, de caráter hereditário, com grande variabilidade de expressão clínica. Afeta fundamentalmente os sistemas esquelético, cardiovascular e ocular. Sua etiologia está relacionada a mutações no gene da fi brilina-1 (FBN1),* localizado no cromossomo 15 (15q21.1). As alterações dento-faciais presentes na síndrome, além de outras características relacionadas ao sistema estomatognático, tornam importantes o reconhecimento desta condição e o adequado manejo do paciente pelo profissional da Odontologia. O objetivo deste artigo é revisar a literatura que relaciona a SM à Odontologia.The Marfan syndrome is an inheritable connec tive tissue disease, with variable clinical expression. The disease affects specially the skeletal, cardiovascular and ocular systems. Mutations in the gene coding for fi brillin on chromosome 15 (FBN1) are known to cause Marfan syndrome. The dentofacial abnormalities present on the disease, as well as other stomatognathic characteristics, make the recognizing and correct managing of these patients important. This paper resumes some of the most important aspects about SM related to Dentistry

Clivagem : opção para tratamento radical de terceiros molares inferiores

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Clivagem : opção para tratamento radical de terceiros molares inferiores

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