Korean J Orthod 2010; 40(5): 349-357 https://doi.org/10.4041/kjod.2010.40.5.349
First Published Date October 31, 2010, Publication Date October 31, 2010
Copyright © The Korean Association of Orthodontists.
Fang Ning, PhD, a and Yinzhong Duan, PhDb
aGraduate Student, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, China.
bProfessor, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, China.
Correspondence to: Yinzhong Duan. Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, P. R.China, 710032. +86 29 84776137; Email: ningfang327@163.com
Objective
The purpose of this study was to evaluate the dentoskeletal and soft tissue profile changes after extraction of two lower first or second premolars in "borderline" adult skeletal Class III cases.
MethodsTwenty-eight patients with "borderline" skeletal Class III malocclusion were studied. All of them were treated by extraction of two lower first or second premolars. Lateral cephalometric radiographs taken at the start and end of treatment were analysed. Twenty-five cephalometric variables were calculated and paired t-tests were performed.
ResultsAfter treatment, no significant changes were noted in the skeletal parameters (p ≥ 0.05). Regarding the dental parameters, the L1-MP angle decreased by 8.1°, the U1-L1 angle increased by 7.7° (p < 0.01), the overjet distance increased by 5.7 mm (p < 0.01), the L1-NB angle decreased by 7.3° and the L1-NB distance decreased by 4.8 mm (p < 0.01). The soft tissue parameters of Li-E, Li-H and Li-RL2 distance decreased by 3.2 mm, 3.4 mm and 4.1 mm respectively (p < 0.01).
ConclusionsOrthodontic camouflage treatment by extraction of two lower first or second premolars provides a viable treatment alternative for "borderline" skeletal Class III cases to achieve a good occlusal relationship.
Keywords: Class III treatment, Diagnosis and treatment planning, Adult treatment, Tooth movement
Korean J Orthod 2010; 40(5): 349-357 https://doi.org/10.4041/kjod.2010.40.5.349
First Published Date October 31, 2010, Publication Date October 31, 2010
Copyright © The Korean Association of Orthodontists.
Fang Ning, PhD, a and Yinzhong Duan, PhDb
aGraduate Student, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, China.
bProfessor, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, China.
Correspondence to: Yinzhong Duan. Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, P. R.China, 710032. +86 29 84776137; Email: ningfang327@163.com
Objective
The purpose of this study was to evaluate the dentoskeletal and soft tissue profile changes after extraction of two lower first or second premolars in "borderline" adult skeletal Class III cases.
MethodsTwenty-eight patients with "borderline" skeletal Class III malocclusion were studied. All of them were treated by extraction of two lower first or second premolars. Lateral cephalometric radiographs taken at the start and end of treatment were analysed. Twenty-five cephalometric variables were calculated and paired t-tests were performed.
ResultsAfter treatment, no significant changes were noted in the skeletal parameters (p ≥ 0.05). Regarding the dental parameters, the L1-MP angle decreased by 8.1°, the U1-L1 angle increased by 7.7° (p < 0.01), the overjet distance increased by 5.7 mm (p < 0.01), the L1-NB angle decreased by 7.3° and the L1-NB distance decreased by 4.8 mm (p < 0.01). The soft tissue parameters of Li-E, Li-H and Li-RL2 distance decreased by 3.2 mm, 3.4 mm and 4.1 mm respectively (p < 0.01).
ConclusionsOrthodontic camouflage treatment by extraction of two lower first or second premolars provides a viable treatment alternative for "borderline" skeletal Class III cases to achieve a good occlusal relationship.
Keywords: Class III treatment, Diagnosis and treatment planning, Adult treatment, Tooth movement