Related Experiment Video
Updated: Feb 16, 2026

SpOT the Correct Tissue Every Time in Multi-tissue Blocks
Published on: May 31, 2015
Soft tissue changes: a comparison between changes caused by the construction bite and by successful treatment with a
Erfan Salloum1, Declan T Millett1, Niamh Kelly1
1Cork University Dental School and Hospital, University College Cork, Cork, Ireland.
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.
Related Concept Videos
Ecological Succession
The Sense of Self: Reflected Self-Appraisal and Social Comparison
Multiple Comparison Tests
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
Block Diagram Reduction
The first step in this process is the identification and relocation of a branch point. A branch point, where a...
Elements of Block Diagrams
A block diagram typically includes essential elements such as comparators, blocks, and feedback loops. Each of these elements...
Evolutionary Relationships through Genome Comparisons

