| Objective: To investigate the treatment design and effects in the treatment of 3patients with skeletal Class Ⅲ malocclusion who had different growth stages.Materials and Methods: We select 3 patients of skeletal Class Ⅲ malocclusion.Their growth stages were pubertal stage,postpubertal stage and adult respectively.Case 1: FYW,a 11-year-old pubertal girl with a chief complain of crossbite and the protruding cannie.She had concave profile,skeletal Class III pattern with lower mandibular plane angel,maxillary retrusion and functional mandibular advancement.The intraoral photographs showed permanent dentition with Class III molar relationships and an anterior crossbite with an overjet of-1.5mm and a deep overbite.The upper and lower arch crowding degree were 10.5mm and 0.5mm.Two-phrase Treatment was involved.The first phrase used a maxillary protraction to promote maxillary growth and release the functional advancement of mandible.Then,used SWA in the second prase to relief crowding,align and level dental arches,coordinate occlusion between arches and obtain normal overjet,overbite and molar relationship.Case 2: WLC was a 14-year-old postpubertal boy with a chief complain of crossbite and a hereditary factor.He had concave profile,skeletal Class III pattern with average mandibular plane angel,mandibular protrusion.The intraoral photographs showed permanent dentition with Class III molar and cannie relationships,an anterior overjet of incisor to incisor,crossbite and openbite of partial teeth.the retrusion of the lower incisors and the protrusion of the upper incisors,12 talon cusp.Model measurement showed abnormal Bolton index.After aligning and leveling dental arches,extraction of 38 and 48,a MIA was inserted in the mandibular buccal shelf region on each side to distal movement of lower dentition.During the treatment,12 talon cusp was grinded Gradually.Interproximal enamel stripping wasn’t performed because of good occlusion.Case 3:CMQ,a 18-year-old female with a chief complain of crossbite and malposed teeth.She had concave profile with retracted upper lip and protrudent lower lip,skeletal Class III pattern with average mandibular plane angel,and prognathic mandible.Intraoral condition included congenital missing of 22,crossbite of partial anterior teeth and left posterior teeth with an anterior overjet of-1.0mm and a mild overbite,left deviation of 2.5mm of upper midline and left deviation of 1.0mm of lower midline,Class III molar relationships and Class Ⅰcannie relationship to the right.Other findings included the protrusion of the upper incisors and uprighting of the lower anterior teeth.The treatment was to extract 34,then distally move the mandibular anterior teeth,retract mandibular anterior teeth,labial tipping upper anterior teeth and mesially migrate left maxillary posterior teeth.Thus,the crossbite relieved,the profile and occlusion relationship improved and the Bolton index coordinated as well.But,all of the upper and lower midline left deviated.Result: After the treatment,the anterior crossbite was corrected.There was a good alignment and leveling of teeth in both arches without gaps.The occlusion relationships of molar and canine achieved Class I on both sides.The overbite and overjet also got to the normal.And the profile improved simultaneously.Conclusion:(1)The treatment of skeletal Class Ⅲ malocclusion is closely related to growth.(2)The rational use of maxillary protraction and mandibular buccal shelf micro-screw will obtained.a satisfactory result.(3)Individualized treatment plan should be performed according to each patient’s condition and demands for skeletal Class Ⅲ malocclusion patient with unilateral lateral incisor missing. |
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