Prevalence and Inheritance Pattern of Midline Diastema among Ijaws of Nigeria

Midline diastema is the space between the mesial surfaces of central incisors greater than 0.5mm. The prevalence of midline diastema varies greatly with age, gender and race. The present study was conducted to establish the prevalence and inheritance pattern of natural midline diastema among the Ijaw ethnic group of South-South Nigeria. The study involved 363 respondents (109 males and 254 females) with natural midline diastema. With an informed consent after clearance by graduate school ethics committee, data was obtained from the subjects both by a structured questionnaire and direct measurement of the width of midline diastema and then subjected to statistical analysis. The mean value for the width of midline diastema was 2.16±0.9lmm and l.87±0.87mm for the natural maxillary and mandibular width respectively. It was more prevalent in females and age group between 28-30years with 70% and 40.8% respectively than males with prevalent rate of 30% and older age group at p<0.05. The maxillary arch showed highest prevalent of 70%, followed by the co-existing with 17.1 % and 12.9% for mandibular. The trait midline diastema occurs in two contrasting allelic forms and genetically transmitted by Mendallian recessive-dominant pattern with the presence of the diastema dominant over its absence. Therefore midline diastema has sexual dimorphism showing more prevalence in females. This study can be used in comparative anatomy and genetic analysis as well as in dentistry

Key Words: Midline diastema, Prevalence, Inheritance-pattern, Ijaw