Torque changes of anchorage units in preadolescent patients treated with a digitally designed tooth-borne expander anchored to deciduous vs. permanent molars.

AIM: To compare the effects on permanent or deciduous anchorage dental units in patients treated with a digitally designed palatal expander. METHODS: Inclusion criteria were the following: presence of maxillary transverse deficiency, no previous orthodontic treatment, no extractions, absence of agenesis, congenital pathologies and cranio-maxillofacial malformations. Twenty patients (11 males, 9 females, 11 ± 1.8 years) received a digitally designed and metal printed palatal expander anchored on first permanent molars and 1 activation per day for 30 days (Group 1). Twenty-one patients (12 males, 9 females, 8.6 ± 1.4 years) received a digitally designed and metal printed palatal expander anchored on second deciduous molars and 2 activations per day for 14 days (Group 2). Digital intraoral scans were taken before expansion and after device removal, and torque and the palatal transverse diameter were digitally measured. The FDI notation was used to indicate each tooth CONCLUSION: Less dental torque augmentation was produced in Group 2. RESULTS: Significant intragroup differences over time were found in Group 1 considering the torque of teeth 1.6, 1.4, 1.3, 2.1, 2.4, 2.5, 2.6. Significant differences between groups were found regarding the longitudinal change in torque of teeth 1.5, 2.4 and 2.5. Significant intragroup differences over time were found in both groups considering all transverse diameter parameters. No significant differences were found between groups in the transverse diameter modifications over time. CONCLUSION: Less dental torque augmentation was produced in Group 2.

New 3D printed polymers in orthodontics: a scoping review.

AIM: The aim of this scoping review is to assess the application of new 3D printed polymeric materials in orthodontics, including polyamide-12 (PA-12) and Shape Memory Polymers (SMPs). METHODS: A search for articles published until January 2023 was carried out using PubMed, Scopus, Web of Knowledge, Lilacs, Opengrey, Embase and Cochrane Library databases and by applying the search terms (orthodontic* OR paediatric* OR paedodontic*) AND ("3D printed" OR "three-dimensional printed") AND (polymer* OR material* OR resin* OR technopolymer*). Additional records were also screened through hand or electronic search. No restriction in terms of language or publication period was applied. CONCLUSION: Due to their mechanical, aesthetic and biocompatibility characteristics, PA12 and SMPs can be used in orthodontic practice. However, additional studies should be performed to evaluate the clinical efficiency of these recent materials.

3D facial soft tissue changes after rapid maxillary expansion on primary teeth: A randomized clinical trial.

OBJECTIVES: The aim of the present randomized controlled trial (RCT) was therefore the tridimensional evaluation of soft tissue changes after rapid maxillary expansion in growing patients. SETTING AND SAMPLE POPULATION: Treated group comprised 17 patients (10 males and 7 females) with a mean age of 9.8 ± 1.2 years, and control group comprised 17 patients (13 males and 4 females) with a mean age of 9.1 ± 2.1 years. MATERIAL & METHODS: All patients of the treated group underwent maxillary expansion with Haas-type expander while patients of the control group underwent no treatment. 3D facial scans were acquired at T1, at the beginning of treatment or observation period, and at T2, 18 months apart. The mean interval between the timepoints was 18.2 ± 0.4 months. RESULTS: The main differences between groups were reported in the nasal area. Nasal width (Alr-All) significantly increased in the treated group compared with the control. The increase in intereye and mouth width in the study group did not show differences with the control group. No significant differences were reported for lips' protrusion, angular measurements and facial heights between groups. The total nose volume difference was significantly higher in the treated group compared with control, and this result was related mainly to the significant increase in the nasal dorsum volume. CONCLUSION: Maxillary expansion produced significant increase in the nasal base and nasal volumes, but its clinical relevance is still questionable.