The recent introduction of three-dimensional (3D) printing is revolutionizing dentistry and is even being applied to orthodontic treatment of malocclusion. Clear, personalized, removable aligners are a suitable alternative to conventional orthodontic appliances, offering a more comfortable and efficient solution for patients. Including improved oral hygiene and aesthetics during treatment. Contemporarily, clear aligners are produced by a thermoforming process using various types of thermoplastic materials. The thermoforming procedure alters the properties of the material, and the intraoral environment further modifies the properties of a clear aligner, affecting overall performance of the material. Direct 3D printing offers the creation of highly precise clear aligners with soft edges, digitally designed and identically reproduced for an entire set of treatment aligners; offering a better fit, higher efficacy, and reproducibility. Despite the known benefits of 3D printing and the popularity of its dental applications, very limited technical and clinical data are available in the literature about directly printed clear aligners. The present article discusses the advantages of 3D printed aligners in comparison to thermoformed ones, describes the current state of the art, including a discussion of the possible road blocks that exist such as a current lack of approved and marketed materials and limited existence of aligner specific software. The present review suggests the suitability of 3D direct printed aligners is superior to that of thermoformed manufactured aligners because of the prior’s increased accuracy, load resistance, and lower deformation. It is an overall more stable way to produce an aligner where submillimeter movements can make a difference in treatment outcome. Direct 3D printing represents a complex method to control the thickness of the aligner and therefore has a better ability to control the force vectors that are used to produce tooth movement. There is currently no other approved material on the market that can do this. The conclusion of this article is that we encourage further in vitro and in vivo studies to test these new technologies and materials.

Objective: The aim of this prospective study was to compare the periodontal health and the microbiological changes via real-time polymerase chain reaction (PCR) in patients treated with fixed orthodontic appliances and Invisalign^® system (Align Technology, Santa Clara, California). Materials and Methods: Seventy-seven patients were enrolled in this study and divided into three groups (Invisalign^® group, fixed orthodontic appliances group and control group). Plaque index, probing depth, bleeding on probing were assessed. Total biofilm mass and periodontal pathogens were analyzed and detected via real-time PCR. All these data were analyzed at the T0 (beginning of the treatment) T1 (1-month) and T2 (3 months); and statistically compared using the Mann–Whitney test for independent groups. Results: After 1-month and after 3 months of treatment there was only one sample with periodontopathic anaerobes found in patient treated using fixed orthodontic appliances. The Invisalign^® group showed better results in terms of periodontal health and total biofilm mass compared to the fixed orthodontic appliance group. A statistical significant difference (P < 0.05) at the T2 in the total biofilm mass was found between the two groups. Conclusion: Patients undergoing orthodontic treatment with the Invisalign^® System show a superior periodontal health in the short-term when compared to patients in treatment with fixed orthodontic appliances. Invisalign^® should be considered as a first treatment option in patients with risk of developing periodontal disease.

The purpose of this study was to explore the microbiological and periodontal changes occurring in adolescents during 12 months of orthodontic therapy with removable aligners and with fixed appliances. During the years 2012–2013, 50 teenagers aged 10–18 years with similar initial orthodontic conditions participated in this trial in a university clinic in northern Italy. After receiving professional oral hygiene and instructions on a standardized oral hygiene protocol, the adolescents were randomly assigned to either orthodontic treatment with traditional fixed brackets (n = 25) or to treatment with Invisalign® aligners (n = 25). Subgingival microbiological samples, probing depth (PD), plaque index (PI), and bleeding on probing (BOP) were obtained and documented from the mesiovestibular subgingival sulcus of the upper right first molar and left central incisor at the beginning of treatment and 3, 6, and 12 months later. Compliance with oral hygiene procedures, full mouth plaque score (FMPS), and full mouth bleeding score (FMBS) were assessed at the beginning of treatment and 12 months later. Two sample independent t-tests and the χ² test were used to study whether the indices of periodontal health differed in the teenagers due to the experimental conditions. None of the patients was positive for the periodontal anaerobes analyzed. The PI, PD, BOP, FMPS, and FMBS scores were significantly lower and compliance with oral hygiene was significantly higher in the group treated with Invisalign® than in the group treated with fixed brackets. Teenagers treated with removable appliances display better compliance with oral hygiene, less plaque, and fewer gingival inflammatory reactions than their peers with fixed appliances. Gegenstand dieser Untersuchung waren die mikrobiologischen und parodontalen Veränderungen bei Jugendlichen über 12 Behandlungsmonate mit herausnehmbaren Alignern oder festsitzenden Apparaturen. Die Studie umfasst 50 Teenager (10–18 Jahre) mit vergleichbaren kieferorthopädischen Indikationen, behandelt in den Jahren 2012 und 2013 an einer norditalienischen Universitätsklinik. Nach einer professionellen Hygienesitzung und Unterweisung in einem standardisierten Mundhygieneverfahren erfolgte nach dem Zufallsprinzip die Zuordnung der Jugendlichen zu einer von 2 Behandlungsgruppen mit traditionellen Klebebrackets (n = 25) oder Invisalign®-Schienen (n = 25). Zu Behandlungsbeginn sowie 3, 6 und 12 Monate danach erfolgten mikrobiologische Probenentnahmen im Oberkiefer aus dem mesiovestibulären Sulkusbereich des rechten ersten Molaren und linken mittleren Schneidezahns sowie eine Beurteilung auf Sondiertiefen, Plaqueindex und provozierte Blutungen. Außerdem beurteilten wir zu Behandlungsbeginn und 12 Monate danach die Hygienedisziplin sowie die Gesamtindizes FMPS (Full Mouth Plaque Score) und FMBS (Full Mouth Bleeding Score). Zweistichproben-t-Tests für unabhängige Stichproben und der χ²-Test dienten dem Auffinden von Gruppenunterschieden bei den parodontalen Indizes. Tests auf 4 anaerobe Parodontalkeime waren für alle Patienten negativ. Die Invisalign®-Gruppe zeigte gegenüber der Bracket-Gruppe signifikant niedrigere Werte für Plaqueindex, Sondiertiefen, provozierte Blutungen sowie FMPS- und FMBS-Werte. Auch die Hygienedisziplin war in der Invisalign®-Gruppe signifikant besser. Im Vergleich zu Gleichaltrigen mit festsitzenden Apparaturen zeigten die mit herausnehmbaren Aligners behandelten Teenager eine bessere Hygienedisziplin sowie weniger Plaque und Entzündungsreaktionen.

Habitual snoring and obstructive sleep apnoea in children, which are frequently associated with adenotonsillar hypertrophy, may begin early in life and in relation with orocraniofacial features. The aim of this study was to detect the presence of early bone craniofacial modifications in young children with a long history of habitual snoring. Twenty-six habitually snoring children (mean age 4.6 yrs) were studied by nocturnal portable recording or diurnal polysomnography, cephalometry and orthodontic evaluation. A comparison of cephalometric findings was made between the studied group and 26 age-matched children (mean age 5.1 yrs) with no history of snoring or respiratory problems during sleep. The cephalometric analyses showed a significant increase in craniomandibular intermaxillar, lower and upper goniac angles with a retroposition and posterior rotation of the mandible (high angle face) and a reduction in the rhinopharynx space caused by higher thickness of adenoids in habitually snoring children compared with controls. Cross-bites and labial incompetence as well as daytime symptoms and familiarity for habitual snoring were found in most of the studied group of snorers compared with controls. The results indicate that upper airway obstruction during sleep is associated with mild but significant cephalometric and craniofacial modifications in children complaining of habitual snoring. Whether this skeletal conformation is genetically determined or influenced by the early onset of habitual snoring remains to be assessed.

Objectives: The aim of the present systematic review and meta-analysis is to assess the accuracy of automated landmarking using deep learning in comparison with manual tracing for cephalometric analysis of 3D medical images. Methods: PubMed/Medline, IEEE Xplore, Scopus and ArXiv electronic databases were searched. Selection criteria were: ex vivo and in vivo volumetric data images suitable for 3D landmarking (Problem), a minimum of five automated landmarking performed by deep learning method (Intervention), manual landmarking (Comparison), and mean accuracy, in mm, between manual and automated landmarking (Outcome). QUADAS-2 was adapted for quality analysis. Meta-analysis was performed on studies that reported as outcome mean values and standard deviation of the difference (error) between manual and automated landmarking. Linear regression plots were used to analyze correlations between mean accuracy and year of publication. Results: The initial electronic screening yielded 252 papers published between 2020 and 2022. A total of 15 studies were included for the qualitative synthesis, whereas 11 studies were used for the meta-analysis. Overall random effect model revealed a mean value of 2.44 mm, with a high heterogeneity (I² = 98.13%, τ² = 1.018, p-value < 0.001); risk of bias was high due to the presence of issues for several domains per study. Meta-regression indicated a significant relation between mean error and year of publication (p value = 0.012). Conclusion: Deep learning algorithms showed an excellent accuracy for automated 3D cephalometric landmarking. In the last two years promising algorithms have been developed and improvements in landmarks annotation accuracy have been done.