1. Clinical observations relating to the normal and abnormal frenum labii superians;Taylor;Am J Orthod,1939
2. Biracial study of the maxillary midline diastema;Richardson;Angle Orthod,1973
3. Maxillary diastema: Indications for treatment;Popovich;Am J Orthod,1979
4. Distribution of diastema in the dentition of man;Keene;Am J Phys Anthropol,1963
5. The median diastema;Becker;Dent Clin North Am,1978