Wednesday, June 15, 2011

A Study of Children with Unilateral Posterior Crossbite, Treated and Untreated, in the Deciduous Dentition.

Resident: J. Hencler DMD
Date: 06/15/2011

Article title: A Study of Children with Unilateral Posterior Crossbite, Treated and Untreated, in the Deciduous Dentition
Author(s): Thilander, Lennartsson

Journal: Journal of Orofacial Orthopedics
Major topic: Posterior crossbites: Tx vs. Non-tx and long term outcomes

Main Purpose:
Analyze whether occlusal and skeletal characteristics could be found in the deciduous dentition of children w/ tx success (including self-correction) in contrast to those showing non-correction (including relapse) in the young permanent dentition.

Overview of method of research:
Two grps of children w/ unilateral posterior crossbite were followed from age 5-13yo. The children in one grp were txed in the deciduous dentition while the second grp was txed in the late mixed or early perm dentition. Another 25 children w/ excellent occlusion were included as control grp. Results of clinical examination and biometric and ceph analyses, performed at the first exam, are presented for the three grps.

Key points in the article discussion:
The width of the dental arches seem to be significant in predicting long term outcome in crossbite cases. DUH! Unilateral crossbite is chacterized by asymmetry in the upper dental arch as well as the lower dental arch. The differences b/t the crossbite and non-crossbite sides in both arches appeared relevant to the prediction of long term outcome. A broader upper than lower crossbite side was found in children showing self-correction and correction after expansion tx, while narrower upper than lower crossbite side was found only in non-corrected subjects. If crossbite is left untreated adaptive processes such as TMJ remodeling my lead to craniofacial asymmetry.

Summary of conclusions:
This study has shown that tx of unilateral posterior crossbite is not equivalent to expansion of the upper dental arch but is associated w/ biometric and ceph characteristics of importance for long term result. The aim of early tx in deciduous dentition is to allow the 1st perm molars to erupt in dental arches with ideal transverse dimensions. Selective grinding is performed to eliminate forced guidance of the mand. This will facilitate normal intermaxillary relationship for muscular balance and craniofacial devel. In cases of non-correction after selective grinding, corrective tx is indicated w/ the aim of creating symmetric dental arches and muscle funct. Narrow upper and broad lower dimensions will result in failure if an expansion appliance is used in the upper jaw only.

Assessment of article:
This article was confusing with much biometric and ceph analyses. Seems geared more for an ortho resident. The translation from Swedish to English made for a difficult read. Overall though okay.

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