Abstract | Background/objectives: Functional appliances are commonly used to correct Class II malocclusion. This study aimed to compare the facial soft tissue changes in Caucasians between pre-treatment and with the construction bite versus pre-treatment and completion of treatment with a modified Twin-block appliance ( MTBA). Materials and methods: Fifty-eight Caucasian subjects with Class II division 1 malocclusion had 3D stereophotogrammetric images captured pre-treatment (T1), with the construction bite (T2), and on completion of MTBA treatment (T3). Twenty-six landmarks were located on each image and 10% were re-landmarked 1 month later. Soft-tissue linear and volumetric changes (T1-T2 and T1-T3) were analyzed using linear mixed effect models (SAS® Version 9.4, www.sas.com). Results: Forty-seven subjects [mean age 13.2 (SD 1.7) years] completed treatment [mean duration 9.8 (SD 3.8) months]. Differences between the changes from T1 to T2 versus T1 to T3 for upper facial and upper lip landmarks were insignificant (all P > 0.05) except for nasion, orbitale right, pronasale, and subnasale. For the same comparisons, lower lip and chin landmarks changed significantly (all P < 0.05) as did facial soft tissue volume (P< 0.0001). Limitations: There was no control group. Conclusion: The facial soft tissue changes from pre-treatment to with the construction bite were considerably more than those from pre-treatment to completion of treatment with a MTBA. Implication: With MTBA treatment, the soft tissue changes from pre-treatment to with the construction bite in situ, overestimate those from pre- to post-treatment.
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Authors | Erfan Salloum, Declan T Millett, Niamh Kelly, Grant T McIntyre, Michael S Cronin |
Journal | European journal of orthodontics
(Eur J Orthod)
Vol. 40
Issue 5
Pg. 512-518
(09 28 2018)
ISSN: 1460-2210 [Electronic] England |
PMID | 29300850
(Publication Type: Journal Article)
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Topics |
- Adolescent
- Anatomic Landmarks
(pathology)
- Cephalometry
(methods)
- Child
- Chin
(pathology)
- Dental Occlusion
- Face
(pathology)
- Female
- Humans
- Imaging, Three-Dimensional
- Lip
(pathology)
- Male
- Malocclusion, Angle Class II
(pathology, therapy)
- Orthodontic Appliance Design
- Orthodontic Appliances, Functional
- Orthodontics, Corrective
(instrumentation, methods)
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