Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Apr 21;29(5):257.
doi: 10.1007/s00784-025-06328-y.

Factors affecting expansion predictability of clear aligner treatment

Cristina de-la-Rosa-Gay  1   2 , Eduard Valmaseda-Castellón  1   2 , Rui Figueiredo  3   4   5 , Octavi Camps-Font  1   2
Affiliations

Factors affecting expansion predictability of clear aligner treatment

Cristina de-la-Rosa-Gay et al. Clin Oral Investig. .

Abstract

Objectives: To determine the clinical factors associated with expansion predictability using clear aligners.

Materials and methods: Pretreatment, prediction in the first approved ClinCheck, and pretreatment of the first refinement digital casts were recovered from Invisalign's ClinCheck software for 98 patients with permanent dentition. Arch width measurements were collected in the ClinCheck arch width table for canines, first and second premolars, and first molars. Expansion predictability was calculated by subtracting the expansion achieved from that predicted. Expansion predictors were explored using univariate and multivariate generalized linear mixed models (GLMM).

Results: Ninety-eight patients (mean age 48.7 years, standard deviation [SD] = 12.5 years) with 1440 eligible teeth (720 on each side) were assessed. The absolute difference between planned and achieved expansion was 0.92 mm (95% confidence interval [CI]: 0.86-0.99). While 72.2% of the measurements showed some degree of underexpansion, 79.3% of all overcorrections appeared in the mandible. According to the univariate analysis, the following variables were associated with expansion predictability: sex, arch, presence of posterior crossbite, absence of extractions, placement of attachments, absence of stripping, tooth type and higher predicted expansion. Those identified by GLMM were arch, tooth type, amount of predicted expansion and posterior crossbite.

Conclusions: Expansion with Invisalign aligners is more reliable in the lower jaw and in the canine region. Cases with large, planned expansions or initial posterior crossbites (unilateral or bilateral) seem less predictable.

Clinical relevance: The risk of not achieving the planned expansion is greater in the maxilla, posterior teeth, and when crossbite is present.

Keywords: Aligner; Aligner therapy; Aligner treatment; Clear aligner; Expansion; Invisalign; Orthodontic tooth movement.

PubMed Disclaimer

Conflict of interest statement

Declarations. Competing interests: Eduard Valmaseda-Castellón, Rui Figueiredo and Octavi Camps-Font have received research funding and honoraria from AVINENT (Santpedor, Spain), and research funding from NOBEL BIOCARE (Kloten, Switzerland). Both companies manufacture and sell clear aligners. Cristina de-la-Rosa-Gay has no relevant conflicts of interest. The authors also want to declare the following conflicts of interest outside the submitted work:Eduard Valmaseda-Castellón, Rui Figueiredo and Octavi Camps-Font have received research funding and honoraria from AVINENT (Santpedor, Spain), and research funding from NOBEL BIOCARE (Kloten, Switzerland). Both companies manufacture and sell clear aligners. Cristina de-la-Rosa-Gay has no relevant conflicts of interest. The authors also want to declare the following conflicts of interest outside the submitted work: Dr. Eduard Valmaseda-Castellón reports grants, personal fees, and non-financial support from MozoGrau (Valladolid, Spain), Inibsa Dental (Lliçà de Vall, Spain), Dentaid SL (Cerdanyola del Vallés, Spain), and personal fees from Laboratorios Silanes (Mexico city, Mexico) outside the submitted work. Dr. Eduard Valmaseda-Castellón has also participated as a principal investigator in a randomized clinical trial sponsored by Geistlich Pharma AG (Wolhusen, Switzerland) and in other clinical trials as a sub-investigator for Mundipharma (Cambridge, UK). Dr. Octavi Camps-Font reports grants and non-financial support from Inibsa Dental (Lliçà de Vall, Spain) and Dentaid SL (Cerdanyola del Vallés, Spain) outside the submitted work.

Figures

Fig. 1
Fig. 1
Boxplot of the absolute difference between predicted and achieved expansion by arch and tooth. Boxes indicate Q1, median and Q3. Single values are represented as scattered points. This image was created using STATA 14 (StataCorp LLC; College Station; TX, USA)
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Cooper-Kazaz R, Ivgi I, Canetti L et al (2013) The impact of personality on adult patients’ adjustability to orthodontic appliances. Angle Orthod 83:76–82. 10.2319/010312-6.1 - PMC - PubMed
    1. Muro MP, Caracciolo ACA, Patel MP et al (2023) Effectiveness and predictability of treatment with clear orthodontic aligners: A scoping review. Int Orthod 21:100755. 10.1016/j.ortho.2023.100755 - PubMed
    1. Blundell HL, Weir T, Byrne G (2023) Predictability of anterior open bite treatment with invisalign. Am J Orthod Dentofac Orthop 164:674–681. 10.1016/j.ajodo.2023.04.017 - PubMed
    1. Blundell HL, Weir T, Byrne G (2022) Predictability of overbite control with the invisalign appliance comparing SmartTrack with precision bite ramps to EX30. Am J Orthod Dentofac Orthop 162:e71–e81. 10.1016/j.ajodo.2022.05.012 - PubMed
    1. Rossini G, Parrini S, Castroflorio T et al (2015) Efficacy of clear aligners in controlling orthodontic tooth movement: a systematic review. Angle Orthod 85:881–889. 10.2319/061614-436.1 - PMC - PubMed