GSTM1 null polymorphism: a possible key for oral carcinogenesis

Introduction: Carcinogenesis is a multistep process and individual risk to development of cancer depends not only on environmental factors or extrinsic exposure to carcinogens but also on genetic susceptibility of an individual. In head and neck cancer, tobacco exposure and alcohol consumption are predominantly the most significant external factors for tumor formation. Individual's susceptibility to cancer may be partly explained by variability in enzymatic activities of metabolic genes. Mutations in genes concerned with production of enzymes for metabolism of tobacco products may lead to increased risk of carcinogenesis with respect to oral mucosa. Therefore variations in the expression of these genes due to heritable genetic polymorphisms might modulate the process of carcinogenesis by altering the exposure levels of tobacco derived carcinogens. Objective:This non systematic review summarizes current data available on the role of environment gene interaction in form of GSTM1 null polymorphism and oral carcinogenesis. Literature review: Relevant data was selected in order to summarize the studies conducted on GSTM1 null polymorphism and oral cancer. Conclusion: Relationship between GSTM1 null polymorphism in oral cancer needs to be established to confirm the role of environment gene interaction in oral carcinogenesis.

Comparative study between cervical vertebrae and hand-wrist maturation for the assessment of skeletal age / Estudo comparativo entre maturação de vértebras cervicais e da mão e punho para a determinação da idade esqueletal

Objectives: The aim of the study was to compare the cervical vertebrae maturity, using a lateral cephalogram,which is routinely taken before orthodontic treatment and is included as a part of the patient’srecord, with hand-wrist maturation method. Materials and methods: The study group comprised ofsixty subjects of Bangalore, Indian, origin, aged between 9-18 years. Hand wrist radiograph and lateralcephalograms were taken for these subjects. Assessment of skeletal maturation was done using SkeletalMaturity Indicators (SMI’s) from hand-wrist radiograph and Cervical Vertebrae Maturity Indicators(CVMI’s) from lateral cephalogram. A pair wise comparison for skeletal age assessment stages was doneusing Wilcoxon sign rank test and proportions was compared using Chi-Square test for statistical analysis.Results: Skeletal maturity assessed using the cervical vertebrae maturation index (CVMI) method andhand-wrist skeletal maturational index (SMI) method showed no statistical signifi cant difference for malesand females. However, females showed maturation at an early age as compared to males. Conclusions:Since properly utilized cervical vertebrae assessment provided a reliable assessment of pubertal growthspurt, it would be benefi cial to use a lateral cephalogram for skeletal maturity assessment and thereby eliminate the need for an additional radiograph (hand-wrist radiograph). This is cost effective and will alsoreduce the radiation exposure to the patient.

Objetivos: O objetivo do presente estudo foi comparar a maturidade das vértebras cervicais, por meio de umcefalograma lateral, que é rotineiramente obtido antes de tratamentos ortodônticos, com um método de medição dematuração de mão e punho. Materiais e métodos: O grupo estudado consistiu de sessenta indivíduos da região deBangalore, Índia, com idades entre 9 e 18 anos, de ambos os sexos. Radiografi as de mão e punho e cefalogramas emnorma lateral foram obtidos. A determinação da maturação esquelética foi determinada com o uso de Indicadoresde Maturidade Esquelética para radiografi as de mão e punho e Indicadores de Maturidade de Vértebras Cervicaispara cefalogramas em norma lateral. A comparação por pareamento para determinação da idade esqueletal foi feitautilizando o teste de ranqueamento de Wilcoxon e as proporções comparadas pelo teste Qui-Quadrado para análiseestatística. Resultados: A maturidade esquelética determinada pelo índice de maturação esquelética não mostroudiferença estatística signifi cante para homens e mulheres. Entretanto, em mulheres a maturação ocorreu em idademais precoce quando comparadas com os homens. Conclusões: Uma vez utilizado adequadamente, o método dedeterminação da maturidade das vértebras cervicais proporciona um indicativo confi ável do crescimento no estirãoda puberdade, o qual pode ser útil no estabelecimento da maturidade esqueletal por meio de cefalogramas laterais,eliminando assim a necessidade de radiografi as adicionais de mão e punho. Essa eliminação das radiografi as de mãoe punho é custo-efetiva e igualmente reduz a exposição do paciente à radiação ionizante.