1. Brunelle JA, Bhat M, Lipton JA. Prevalence and distribution of selected occlusal characteristics in the US population 1988-1991. J Dent Res 1996; 75:706-713.
2. Richardson ER, Malhotra SK, Henry M, Little RG, Coleman HT. Biracial study of the maxillary midline diastema. Angle Orthod 1973; 43:438-443.
3. Steigman S, Weissberg Y. Spaced dentition: an epidemiologic study. Angle Orthod 1985; 55:167-176.
4. Sullivan TC, Turpin DL, Artun JA. A post-retention study of patients presenting with a maxillary median diastema. Angle Orthodontics. 1996; 66:131-38.
5. Mclaughlin RP, Bennett JC, Trevisi HJ. Systemized orthodontic treatment mechanics, Mosby International, 2001.