Dialogic education advocates varied forms of interactional management by teachers. In the context of whole-class discussions, teachers are encouraged to both prompt student involvement through direct mediation, and "step back" to give students a greater sense of agency and responsibility for turn-taking when appropriate. However, it is methodologically challenging to capture the relation between teacher-student and student-student interactions through dialogue in whole-class contexts. One perspective that is especially designed for exploring complex relations in social networks but not as commonly used in dialogic education is social network analysis (SNA). Drawing on 35 whole-class discussion episodes derived from lower secondary classrooms in Norway, this study uses SNA to explore interactional patterns. Methodologically, the study provides novel examples of how SNA can be used both alone and in conjunction with the indicators of interactional productivity to describe the relation between teacher-student and student-student interactions in whole-class discussions. Empirically, a key finding is that an increase in students responding directly to each other in a student-to-student fashion is associated with a reduction in the distribution of productive interactions through dialogue. Theoretically, the study directs attention to the complexities and tensions inherent in key models and concepts in dialogic education.