Final answer:
Closure of the anterior fontanel at 9 months is a normal part of child development and does not require a referral. Other findings like head lag at 4 months, hyperextension of the head with pain, and an enlarged thyroid gland are abnormal and may need further evaluation.
Step-by-step explanation:
Among the assessment findings of the head and neck, the closure of the anterior fontanel at the age of 9 months does not require a referral. The anterior fontanel, which is the larger diamond-shaped soft spot located at the top front of the skull, typically closes between 9 to 18 months after birth. It allows for the growth of the skull after birth, accommodating the enlarging brain. The closure of the anterior fontanel by 9 months is a normal part of child development. On the other hand, findings such as head lag at 4 months of age, hyperextension of the head with pain on flexion, and a palpable, enlarged thyroid gland are abnormal and may require further medical evaluation.