N. A. Koren
Pavlov First Saint Petersburg State Medical University
Russian Federation

Nadezhda A. Koren, DMD, Assistant Professor, Department of the Pediatric Dentistry and Orthodontics

6 Lev Tolstoy Str., Saint Petersburg, 197022

T. B. Tkachenko
Pavlov First Saint Petersburg State Medical University
Russian Federation

Tatyana B. Tkachenko, DMD, PhD, DSc, Professor, Dean of the Dental School, Head of the Department of Pediatric Dentistry and Orthodontics

Saint Petersburg

O. V. Guseva
Pavlov First Saint Petersburg State Medical University
Russian Federation

Oksana V. Guseva, fourth-year student, Dental School

Saint Petersburg

N. Yu. Sheveleva
Pavlov First Saint Petersburg State Medical University
Russian Federation

Nina Yu. Sheveleva, DMD, PhD, Associate Professor, Department of the Pediatric Dentistry and Orthodontics

Saint Petersburg