Korean J Orthod.  2010 Oct;40(5):349-357. 10.4041/kjod.2010.40.5.349.

Camouflage treatment in adult skeletal Class III cases by extraction of two lower premolars

• Ning F
• Duan Y

• KMID: 2273226
• DOI: http://doi.org/10.4041/kjod.2010.40.5.349

Abstract

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.
METHODS
Twenty-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.
RESULTS
After treatment, no significant changes were noted in the skeletal parameters (p > or = 0.05). Regarding the dental parameters, the L1-MP angle decreased by 8.1degrees, the U1-L1 angle increased by 7.7degrees (p < 0.01), the overjet distance increased by 5.7 mm (p < 0.01), the L1-NB angle decreased by 7.3degrees 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).
CONCLUSIONS
Orthodontic 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.

Keyword

Class III treatment; Diagnosis and treatment planning; Adult treatment; Tooth movement

MeSH Terms

Adult
Bicuspid
Humans
Malocclusion
Tooth Movement

Figure

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  Fig. 1 Skeletal measurements used in the study. SN indicates Sella-nasion plane; RL1, horizontal reference line; RL2, vertical reference line; 1, SNA; 2, SNB; 3, ANB; 4, SN-MP; 5, Pg-NB; 6, A-RL1; 7, A-RL2; 8, B-RL2; 9, Ar-Pg.

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  Fig. 2 Dental measurements used in the study. SN indicates Sella-nasion plane; RL1, horizontal reference line; RL2, vertical reference line; 1, U1-SN; 2, L1-MP; 3, U1-L1; 4, U1-NA (degree); 5, U1-NA (mm); 6, L1-NB (degree); 7, L1-NB (mm); 8, OP-FH; 9, overjet.

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  Fig. 3 Soft tissue measurements used in the study. SN indicates Sella-nasion plane; RL1, horizontal reference line; RL2, vertical reference line; 1, upper lip to E plane; 2, lower lip to E plane; 3, lower lip to H line; 4, Cm-Sn-Ls; 5, Ls-RL2; 6, Li-RL2; 7, A-Ls.

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  Fig. 4 Pretreatment facial photographs. A, Frontal view; B, lateral view

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  Fig. 5 Posttreatment facial photographs. A, Frontal view; B, lateral view.

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  Fig. 6 Pretreatment intraoral photographs. A, Lateral view on the right side; B, frontal view; C, lateral view on the left side; D, occlusal view of maxillary dentition; E, occlusal view of mandibular dentition; F, lateral view of anterior teeth.

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  Fig. 7 Posttreatment intraoral photographs. A, Lateral view on the right side; B, frontal view; C, lateral view on the left side; D, occlusal view of maxillary dentition; E, occlusal view of mandibular dentition; F, lateral view of anterior teeth.

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  Fig. 8 Panoramic radiographs. A, Pretreatment; B, posttreatment.

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  Fig. 9 Lateral cephalometric radiographs. A, Pretreatment; B, posttreatment.

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  Fig. 10 Superimposition of pretreatment and posttreatment cephalometric tracings.

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