Abnormal Muscle Habits
		z Abnormal muscle habits like Mentalis Habit - muscle arises from the mandible near the apices of the incisors and inserted into the soft tissue of the chin, puckering the skin and the lower lip is folded behind the maxillary incisors with the inner surface of the lip elevated upwards. z Placing the lower lip between the maxillary and mandibular incisors. z Frequently arises following development of anterior open bite. z Can be accompanied by skeletal Class I and II relationships.