Assessment of open and incomplete bite correction by incisor overlap and optical density of polyvinyl siloxane bite registration.

Abstract

Open bite (OB) is a generalized term, which could incorporate subgroups that react differently to vertical correction. The objectives of the present study were to detect vertical treatment changes in incomplete bite (IB: inter-incisor overlap with no lower incisor contact with teeth or palate) and OB (no inter-incisor overlap) groups compared with a complete bite (CB: inter-incisor overlap with full lower incisor contact with teeth or palate) control group, to evaluate treatment response of the central and lateral incisors, and to study the vertico-sagittal interaction. Dental casts were taken at three time points, pre-treatment, post-treatment, and after one year of retention, from 54 Class II patients (22 males and 32 females with a mean age of 11 years 6 months) divided into three groups: CB (n = 21), IB (n = 18) and OB (n = 15). Measurements included incisor overlap (mm) and optical density (OD/mm2) of occlusal bite registration made of polyvinl siloxane. Both CB and IB groups demonstrated post-retention bite opening. However, bite opening in the CB group was three times greater than that in the IB group (e.g. lower lateral = -1.42 mm, 118 OD/mm2 versus -0.40 mm, 107 OD/mm2). Conversely, the OB group showed a significant (P < 0.001) bite closure (e.g. lower lateral = 1.30 mm, -377 OD/mm2). Overjet changes affected OD measurements, causing diversity in OD and millimetric measurements of the lateral incisors in the IB group. In conclusion, the OB group demonstrated a significant stable vertical correction; a post-treatment non-contact inter-incisor relationship was determined by a vertico-sagittal relapse; and full compensation of an IB was not possible.

• Authors: Nir Shpack, Shmuel Einy, Lea Beni, Alexander D Vardimon
• Journal: European journal of orthodontics (Eur J Orthod) Vol. 28 Issue 2 Pg. 166-72 (Apr 2006) ISSN: 0141-5387 [Print] England
• PMID: 16267127 (Publication Type: Journal Article)

Chemical References

• Dental Materials
• Polyvinyls
• Siloxanes
• vinyl polysiloxane

Topics

• Child
• Dental Materials (chemistry)
• Female
• Follow-Up Studies
• Humans
• Incisor (pathology)
• Jaw Relation Record (instrumentation, methods)
• Male
• Malocclusion, Angle Class II (classification, therapy)
• Models, Dental
• Open Bite (classification, therapy)
• Optics and Photonics
• Orthodontic Retainers
• Polyvinyls (chemistry)
• Recurrence
• Siloxanes (chemistry)
• Vertical Dimension