Case Analyses Of Skeletal Class ? Malocclusion In Growth Stages And Skeletal Class ? Malocclusion

Objective:Anterior crossbite and protrusive upper front teeth are the common complaints.The aim of the article was to discuss the class ? malocclusion treatment strategy using two cases with different morphologic characteristics and growth potential in growth and development stages.Another aim was to analyze the advantages and disadvantages in the treatment of a class ? malocclusion case with the front teeth protrusion.Methods and materials:The cases were treated by the author during the postgraduate period.Case 1: A female patient of age 7 came with a complaint of anterior crossbite before the growing peak.Her mother had a middle mandibular prognathism.She was diagnosed as skeletal ? malocclusion with normal maxilla and prognathic mandible in a low angle and then was treated with Frankel functional regulator ? appliance to retreat mandible and eliminate anterior crossbite.Case 2: A female patient of age 12 came with a complaint of anterior crossbite and the right deviation of chin after the growing peak.She was diagnosed as skeletal ? malocclusion with normal mandible and an underdevelopment of maxilla in an average angle.The protraction facemask was used in the treatment to promote the maxillary deficiency and then the straight wire appliance was adopted in the second stage to align?level dental arches and coordinate occlusion.Case 3: An 18-year-old female,with "irregular dentition and protrusive upper front teeth " as her main complaint,was in stagnation of growth and development.She was diagnosed as skeletal class ? malocclusion with mandibular underdevelopment and protrusion of upper and lower incisors in an average angle.The orthodontic plan was to remove 14,24,35 and 45 teeth,combined with micro implant to provide rigid anchorage to retract anterior teeth.Results:Two patients with skeletal class ? malocclusion returned to normal overjet and overbite after treatment.In case 1 patient,the mandibular incisors were more tonguereversed than before.It's showed a nice prognosis with the GTRV ratio(Growth Treatment Response Vector)as a tool,calculating the ratio of maxillary horizontal growth change to mandibular horizontal growth change in a period.In case 2,the patient was not that young so that the maxillary growth potential was poor.A combination of maxillary protraction and rapid maxillary expansion achieved the treatment objectives mostly due to the teeth changes.Anyway,it still played a role in improving the position of the nasal base.In case 3,the upper anterior teeth were moved posteriorly with the control of torque.The slight deficiency in the vertical control of the mandible contributed to the clockwise rotation of the mandibular plane.Conclusion:1.Early correction of anterior crossbite could improve the development of maxilla.The GTRV index is the ratio of the change of maxillary level growth to the change of mandibular level in time unit,which is helpful to judge the prognosis of skeletal class ? malocclusion and guide the treatment strategy.2.After the peak period of growth and development,the tooth-borne appliances in the interceptive treatment of Class ? malocclusions poses problems of unwanted dental changes such as the mesial movement of maxillary molars.In the second phase there is a need to conduct a control of the incisor torque to prevent damage to the periodontal health beyond the limit.3.Micro-screw implant with a tall hook comes into play in retracting anterior incisors.At the same time,we should take into account the vertical control of the mandible and emphasize the control of mandibular incisors and molar position in order to achieve the most ideal correction effect.