Cases Analysis Of Angle's Class ??? Malocclusion

Objective: To discuss the correction of 4 first premolars for class II open bite with crowding,which was correction of 4 first premolars with Class I malocclusion with congested dentition,which was correction of Class I malocclusion with anterior protrusion by extraction of 4 first premolars.The design,therapeutic effect and characteristics of 3 cases were summarized.Materials and Methods We Select the Department of Orthodontics of the first affiliated Hospital of Fujian Medical University.Case 1 : LYX,a 19 year-old female.Her main problem is bucktooth.She had convex profile,asymmetry of face,mental left deviation,chin lip shallow,upper midline 1 mm,lower midline normal,spee curve 3 mm on the left and 2.5 mm on the right.The main diagnoses include skeletal Class?,Angle Class?malocclusion,average angle,Open lip teeth,open bite between 12,22,Upper arch crowding quantity 2 mm,lower arch crowding quantity 2 mm.The opening of temporomandibular joint had elastic sound,no pain,no tenderness,no limitation of opening,normal mandibular movement,normal opening type and degree of opening.We decided to pull out four first premolars,adductive anterior teeth,reducing the protrusions of the anterior teeth,improvement of side appearance,establishing the relationship between normal overburden and overburden.Case 2 : LSY was a 18 years-old female whose chief complaint was buck teeth.The main diagnoses include skeletal Class?,Angle? malocclusion,average angle,upper and lower midline positive,lips thicker,gummy smile,convex profile,Upper arch crowding quantity 2 mm,lower arch crowding quantity 1 mm,spee curve is 3 mm on the left and 3 mm on the right side.The temporomandibular joint had no mouth opening,no pain,no tenderness,no mouth opening limitation,mandibular movement was basically normal,and the opening type and opening degree were normal.We pull out four first premolars,use the extraction space to align the dentition,improve the convex profile and establish the relationship between normal overburden and overburden.Case 3 : ZJX was a 20 year-old female,her chief compliant is the protruding and crowing.The main diagnoses include skeletal Class I,Angle ? malocclusion,asymmetry of face,right deviation of the chin,height of the middle and lower 1/3 is normal,upper and lower midline positive,average angle,convex profile,Upper arch crowding quantity 7.5 mm,lower arch crowding quantity 6.5 mm,spee curve 2.5 mm on the left and 1 mm on the right.The opening of temporomandibular joint had elastic sound,no pain,no tenderness,no limitation of opening,normal mandibular movement,normal opening type and degree of opening.We pull out four first premolars,use the extraction space to align the dentition,establishing the relationship between normal overburden and overburden.The four first premolars were extracted,the maxillary internal Anchorage against adductive anterior teeth and the lingual inclination of lower anterior teeth were extracted to establish a normal overbite overlay relationship.Result After orthodontic treatment,3 patients had normal overbite coverage,regular dentition arrangement,good occlusion relationship and good soft tissue profile.Conclusion Orthodontists need to have the correct diagnosis and proper design for patients with different malocclusion malocclusion.At the same time,they need to communicate with the patients and get the cooperation of the patients to get the best correction effect.