system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which primary tooth is generally accepted as the first to erupt, and at about what mean age?
assistant
The correct answer is  Eruption for the primary mandibular central incisor may be given as 6 months (Woelfel and Scheid, 2002); 6.5 months (Kraus et al., 1969); 7.5 months(Charlick et al.); or 8 (6 to 10) months (Ash and
Nelson, 2003).