Comparison of the skeletal, dentoalveolar, and periodontal changes after Ni-Ti leaf spring expander and rapid maxillary expansion: a three-dimensional CBCT based evaluation.

BACKGROUND: The aim of the present study was twofold:(1) three-dimensionally evaluate the quantitative skeletal and dentoalveolar changes after Ni-Ti leaf spring expander (leaf expander) and rapid maxillary expansion (RME) in mixed dentition patients;(2) analyze the modifications of the buccal alveolar bone plate of the maxillary first permanent molars. METHODS: Patients who underwent CBCT scans before and after maxillary expansion were randomly selected from the records archived at the Department of Biomedical Surgical and Dental Sciences, University of Milan, Italy. Inclusion criteria were the following: no systemic disease or syndromes; maxillary transverse deficiencies (difference between the upper intermolar width and the lower intermolar width of at least 3 mm and/or clinical need based on radiographic evaluation), early mixed dentition with ages between 7 to 10 years old; cervical vertebra maturation stage (CVMS) 1 or 2; no pathologic periodontal status; skeletal class I or II; maxillary expander cemented on the upper second deciduous molars. Exclusion criteria were the following: patients with pubertal or post-pubertal stage of development (CVMS 3-6); late deciduous or late mixed dentition, impossibility to use the second primary molar as anchorage; skeletal class III malocclusion; craniofacial syndromes; patients unable to be followed during the treatment period. Twenty-three patients treated with Leaf Expander, 11 males (mean age 7.8 ± 0.6 years) and 12 females (mean age 8.1 ± 0.8 years), met the inclusion criteria and constituted the case group. Twenty-four (control group) treated with conventional RME, 12 males (mean age 8.4 ± 0.9 years) and 12 females (mean age 8.1 ± 0.7 years). The paired-sample T test was used for intra-group comparison to evaluate the difference between before (T1) and after (T2) maxillary expansion. Independent sample t-test was computed to perform between groups comparison of the skeletal, dentoalveolar, and periodontal changes. RESULTS: The Leaf Expander and RME group showed a significant increase between T1 and T2 for most of the skeletal and dentoalveolar variables. Concerning the skeletal variables only the RME demonstrated a significant increase at the level of the posterior nasal (PNW) and apical base width (PABW) and maxillary mid-alveolar width (MMW). Despite this, when compare with the Leaf Expander, the RME group exhibited a statistically larger width increase for only two skeletal parameters: PNW (p = 0.03) and MMW (p = 0.02). No significant changes at the periodontal level were found in either group. CONCLUSIONS: According to the current research, the authors confirm the effectiveness of the Leaf Expander and RME to produce similar skeletal and dentoalveolar effects in mixed dentition subjects. Moreover, the devices anchored to deciduous teeth did not reduce the thickness and height of the buccal bone at the level of the maxillary permanent first molars in either of the two groups.

Oral and throat microbiological changes after orthodontic debonding.

As already known, orthodontic treatment presents a factor of plaque retention, promoting an increase of bacterial growth in the oral cavity. Nevertheless, after orthodontic debonding an alteration of the previous microbiological status may occur. The present study was designed to assess variations among six bacterial species in the oral cavity and the status of oral health after orthodontic debonding. At the end of the fixed orthodontic treatment, 30 patients were divided into three groups based on the type of retention: I - 10 patients were treated with upper and lower fixed retention devices, II - 10 with upper and lower removable retention devices, and III - 10 with lower fixed and upper removable retention devices. To assess the alterations of oral microbiota after orthodontic debonding, two salivary swabs were collected for each individual: the first immediately after debonding (T0) and the other one 6 weeks later (T1). Six species, the ones most correlated with the development of caries and periodontal disease, were selected for microbiological analysis with Real-time PCR: Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum. Furthermore, in order to correlate the microbiological outcomes with the clinical condition, oral health indexes at T0 and T1 were assessed for all patients. Six weeks after debonding, the salivary levels of the bacteria investigated tend to decrease and the values of the oral health indexes tend to improve with all types of treatment considered (p<.05). Salivary bacteria levels and oral health are similarly influenced by fixed and/or removable orthodontic retentions.

Benefits and Implications of Resveratrol Supplementation on Microbiota Modulations: A Systematic Review of the Literature.

Resveratrol is a polyphenol that has been shown to possess many applications in different fields of medicine. This systematic review has drawn attention to the axis between resveratrol and human microbiota, which plays a key role in maintaining an adequate immune response that can lead to different diseases when compromised. Resveratrol can also be an asset in new technologies, such as gene therapy. PubMed, Cochrane Library, Scopus, Web of Science, and Google Scholar were searched to find papers that matched our topic dating from 1 January 2017 up to 18 January 2022, with English-language restriction using the following Boolean keywords: ("resveratrol" AND "microbio*"). Eighteen studies were included as relevant papers matching the purpose of our investigation. Immune response, prevention of thrombotic complications, microbiota, gene therapy, and bone regeneration were retrieved as the main topics. The analyzed studies mostly involved resveratrol supplementation and its effects on human microbiota by trials in vitro, in vivo, and ex vivo. The beneficial activity of resveratrol is evident by analyzing the changes in the host's genetic expression and the gastrointestinal microbial community with its administration. The possibility of identifying individual microbial families may allow to tailor therapeutic plans with targeted polyphenolic diets when associated with microbial dysbiosis, such as inflammatory diseases of the gastrointestinal tract, degenerative diseases, tumors, obesity, diabetes, bone tissue regeneration, and metabolic syndrome.

3D cephalometry on reduced FOV CBCT: skeletal class assessment through AF-BF on Frankfurt plane-validity and reliability through comparison with 2D measurements.

OBJECTIVES: To test the validity of a novel protocol for 3D sagittal jaw discrepancy assessment (skeletal class determination) through comparison with common 2D indexes by the use of reduced FOV (10 × 10) CBCT which shows at least from the Frankfurt plane to the B point vertically, and from the most anterior between A and B point to Po point horizontally. METHODS: A sample of CBCT scans of 109 adult patients (46 females; 63 males; mean age 30 years ± 11.6) equally distributed between I, II and III class was selected. Skeletal class was evaluated with specific software using the distance of A and B point's projection (AF-BF) on FHp (Frankfurt horizontal plane) and compared to 2D common indexes (ANB and Witts appraisal). The validity and reliability of the aforementioned analyses were determined using intra-class correlation coefficients, quadratic weighted Cohen's K and sensitivity. RESULT: A selected range of values of 2.5 ± 2.5 AF-BF showed a solid correlation with the ANB angle (r = 0.846, K = 0.838, p < 0.001) and moderate with Wits appraisal (r = 0.723, K = 0.720, p < 0.001). CONCLUSIONS: AF-BF showed high reliability in skeletal class determination on reduced FOV CBCT without the use of S and N cephalometric landmarks. KEY POINTS: • Reduced FOV CT allows skeletal class determination for orthodontic purposes. • A new 3D-reduced FOV cephalometry is proposed. • AF-BF is a reliable alternative to ANB.

Assessment of condylar volume and ramus height in JIA patients with unilateral and bilateral TMJ involvement: retrospective case-control study.

OBJECTIVES: The objectives of the study are to analyze volumetric differences of condylar volumes in patients with unilateral and bilateral JIA and to compare results with control condylar volumes. MATERIALS AND METHODS: Forty-six CBCT images were analyzed for all patients affected by JIA, 37 females and 9 males (mean age 10.8 ± 4.2) with TMJ involvement (19 unilaterally, mean age 10.9 ± 4.5; 27 bilaterally, mean age 10.7 ± 4.5), and 25 CBCT of subjects without diagnosis of JIA were selected as controls (mean age 10.8 ± 4.2 years). In the case of unilateral JIA, condylar volumes and ramus lengths were compared with healthy condyle and with the compromised one. In the case of bilateral JIA, condyle volume and ramus lengths were compared with healthy one. The Shapiro-Wilk test was used to assess whether the data was normally distributed. Paired t test was applied to compare affected and non-affected condyle in the same patients (P < 0.05). Independent t test was used to evaluate whether the difference between the groups were comparable or significantly different (P < 0.05). RESULTS: For the unilateral JIA group, significant differences comparing affected and non-affected condyles were found. A statistically significant reduction of the volume of the head, neck, and ramus was found in the affected side (P < 0.01). For the bilateral JIA group, statistically significant differences have been found considering the condylar head and neck, the whole condylar volume, and the ramus length compared with the control group (P < 0.05). CONCLUSIONS: Subjects with unilateral JIA have condyles volumetrically smaller than those of the unaffected side and those found in healthy patients. A considerable decrease of the volume of all the anatomical structures considered in the patients with bilateral JIA was found compared with control group. CLINICAL RELEVANCE: The study presents the effects of JIA on different anatomical structures highlighting their dimensional changes, whose sequelae are irreversible if not diagnosed and treated early.

Bilateral Hyperplasia of the Coronoid Process in Pediatric Patients: What is the Gold Standard for Treatment?

OBJECTIVES: The aim of this systematic review of the literature is to describe treatment options for bilateral coronoid process hyperplasia in pediatric patients, to describe etiologic and diagnostic correlations with the treatment, and to evaluate long-term follow-up treatment outcomes. METHODS: A systematic revision of the literature was performed in the Medline, PubMed, Cochrane library, and Embase database up to December 5, 2017. Predetermined Medical Subject Heading keywords were used: "bilateral" or "monolateral" and "coronoid" or "coronoid process" and "hyperplasia" and "temporomandibular joint" or "tmj" and "ankylosis" or "trismus" and "treatment." Results were recorded following PRISMA guidelines. RESULTS: The systematic research produced 1459 results excluding duplicates. Two additional studies from "Grey literature" were also considered. After application of inclusion and exclusion criteria, 38 articles were selected for a qualitative synthesis. Data regarding sex and age of presentation were collected and summarized in a study flow diagram. CONCLUSION: It is possible to conclude that early diagnosis is fundamental to restore stomatognathic multifunction. There is lack of longitudinal studies presenting long-term follow-up to determine treatment stability. Coronoidectomy might be considered gold standard treatment for this pathologic condition.

Current state of the art in the use of augmented reality in dentistry: a systematic review of the literature.

BACKGROUND: The aim of the present systematic review was to screen the literature and to describe current applications of augmented reality. MATERIALS AND METHODS: The protocol design was structured according to PRISMA-P guidelines and registered in PROSPERO. A review of the following databases was carried out: Medline, Ovid, Embase, Cochrane Library, Google Scholar and the Gray literature. Data was extracted, summarized and collected for qualitative analysis and evaluated for individual risk of bias (R.O.B.) assessment, by two independent examiners. Collected data included: year of publishing, journal with reviewing system and impact factor, study design, sample size, target of the study, hardware(s) and software(s) used or custom developed, primary outcomes, field of interest and quantification of the displacement error and timing measurements, when available. Qualitative evidence synthesis refers to SPIDER. RESULTS: From a primary research of 17,652 articles, 33 were considered in the review for qualitative synthesis. 16 among selected articles were eligible for quantitative synthesis of heterogenous data, 12 out of 13 judged the precision at least as acceptable, while 3 out of 6 described an increase in operation timing of about 1 h. 60% (n = 20) of selected studies refers to a camera-display augmented reality system while 21% (n = 7) refers to a head-mounted system. The software proposed in the articles were self-developed by 7 authors while the majority proposed commercially available ones. The applications proposed for augmented reality are: Oral and maxillo-facial surgery (OMS) in 21 studies, restorative dentistry in 5 studies, educational purposes in 4 studies and orthodontics in 1 study. The majority of the studies were carried on phantoms (51%) and those on patients were 11 (33%). CONCLUSIONS: On the base of literature the current development is still insufficient for full validation process, however independent sources of customized software for augmented reality seems promising to help routinely procedures, complicate or specific interventions, education and learning. Oral and maxillofacial area is predominant, the results in precision are promising, while timing is still very controversial since some authors describe longer preparation time when using augmented reality up to 60 min while others describe a reduced operating time of 50/100%. TRIAL REGISTRATION: The following systematic review was registered in PROSPERO with RN: CRD42019120058.

Three-Dimensional Virtual Treatment Planning: Presurgical Evaluation.

OBJECTIVE: This article describes a virtual protocol designed to optimize surgical orthodontic diagnosis and treatment plan. METHODS: A total of 15 patients undergoing orthodontic-surgical treatment have been analyzed with a presurgical virtual three-dimensional (3D) treatment planning, which involves 9 steps. All the patients have been treated with the use of occlusal splint guides projected on the basis of the surgical and orthodontic visualized treatment objective . RESULTS: In all the analyzed patients, a precise and optimal orthodontic presurgical preparation has been obtained. CONCLUSIONS: The 3D analysis seems more precise to interpret than two-dimensional; it provides information and images of craniofacial structures free from perspective distortion and it reduces the steps of the presurgical diagnosis. The simplicity of the protocol described in this paper makes possible to apply it in everyday practice.The study described here allows high-precision planning of orthodontic-surgical therapy and optimization of each treatment phase, with consequent advantages in clinical practice: a more accurate orthognathic surgery with predictable results.

Presurgical virtual three-dimensional treatment planning.

AIM: This article describes an experimental protocol designed to optimize surgical orthodontic diagnosis and treatment plan. MATERIALS AND METHODS: In this study, 15 patients undergoing orthodontic-surgical treatment have been analyzed.The superimposition between models and respective presurgical setup for each group was performed. A best-fit algorithm was used to find the position of the arches in space for which the sum of the discrepancies was the shortest.A punctual variation colorimetric map indicating percentages of areas subjected to different discrepancies was used to evaluate the degree of congruence between the 2 models.Furthermore, for each arch the software provided metric values of maximum positive deviation, maximum negative deviation, mean deviation, and standard deviation that characterize the points compared in the superimposition. RESULTS: For all the considered patients, the orthodontic preparation for surgery was obtained according to the splint guides and the orthodontic planning. CONCLUSION: The protocol described here allows high-precision planning of orthodontic-surgical therapy optimization of each treatment phase, with consequent advantages in clinical practice.

Verification of the reliability of the three-dimensional virtual presurgical orthodontic diagnostic protocol.

The precision of presurgical orthodontic diagnostic protocol plays a key role for the success of orthognathic surgery.Recently, the introduction of cone beam computed tomography and the development of digital technologies led to the possibility to create new virtual protocols of diagnostic protocol.The purposes of this study were to describe the virtual presurgical orthodontic diagnostic protocol experimented by the Orthodontics Department of the University of Milan and to assess its reliability by comparing it with the nonvirtual protocol.The study sample was a group of 18 adult patients who required surgical correction of skeletal asymmetric class II or III malocclusion: 9 of them were subjected to the virtual diagnostic protocol, whereas the other 9 were subjected to the traditional one. A comparison between the 2 methods was carried out by evaluating the degree of the discrepancy between setup and presurgical models in both groups. The values of maximum positive deviation, maximum negative deviation, mean deviation, and standard deviation that characterize the points of the superimpositions were considered.An optimal superimposition (>75%) between the scanning of the setup and presurgical models was obtained for all subjects except for 2 patients with asymmetry. The analysis of the punctual deviation variables did not show statistically significant differences between the techniques.The study suggested a high precision for both diagnostic protocols, and the reliability of the 2 methods is comparable. However, the virtual protocol has several advantages such as quantity of information obtainable, repeatability, and speed of execution.

Comparison of Mechanical Behavior of Clear Aligner and Rapid Palatal Expander on Transverse Plane: An In Vitro Study.

(1) Background: This study aims to investigate, within a controlled laboratory environment, the magnitude of the transversal load and the force decay over time produced by clear aligners in comparison to a Rapid Palatal Expander (RPE). (2) Methods: Resin models of a dental maxillary arch, additively manufactured from an intraoral scan, were inserted in a testing machine with uniaxial load cells to measure the force trend over time expressed by RPE and clear aligners. The mechanical load was recorded during a certain timeframe for both appliances. (3) Results: The force expressed by the RPE ranged from 30 to 50 N for each activation, decreasing with a nonlinear pattern over time. The force expressed by the clear aligner ranged from 3 to 5 N, decreasing with a linear pattern over time. In contrast, the force generated by the clear aligner fell within the range of 3 to 5 N, showing a linear reduction in force magnitude over the observed period of time. (4) Conclusions: The RPE exerted a force magnitude approximately ten times greater than that generated by clear aligners. Nevertheless, it is essential to acknowledge that the oral environment can significantly influence these results. These limitations underscore the need for caution when applying these findings to clinical settings.

Microbiological Analysis of Plaque and Its Composition in Three Patient Groups under Different Orthodontic Treatments.

BACKGROUND: This article analyzes differences in microbiological parameters and periodontal health conditions among three patient groups: those undergoing conventional orthodontic treatment with fixed appliances, patients undergoing orthodontic treatment with clear aligners, and a control group receiving no treatment. MATERIALS AND METHODS: In this study, 60 patients were enrolled. The microbiological analysis employed a qualitative and semi-quantitative methodology of bacterial morphotype analysis. RESULTS: The analyses revealed a significant difference in favor of clear oral and periodontal health aligners. This could be attributed to better bacterial biofilm removal and reduced mechanical stress on the periodontal ligament, factors facilitated by the ease of clear aligner removal. Significant differences (p-value < 0.05) were observed for the Full-Mouth Plaque Score, Full-Mouth Bleeding Score, Plaque Index, and periodontal health assessment measurements. CONCLUSIONS: Although overall hygiene appears to be improved in patients in the aligners group compared to those treated with conventional orthodontic appliances, there are no statistically significant results regarding plaque composition. Microbiological aspects will be further addressed using more specific techniques in the follow-up of this research.

Cone-Beam Computed Tomography (CBCT) Analysis of Mandibular Condyles' Diameters in Patient with Juvenile Idiopathic Arthritis and Temporomandibular Joint Affection: A Cross-Sectional Investigation.

Objectives: The aim of this study was to evaluate through analysis using CBCT the transverse and axial diameters of the mandibular condyles in subjects affected by juvenile idiopathic arthritis (JIA) and compare them with those of healthy subjects. Methods: The study was conducted on CBCT scans from the digital archive of the Department of Biomedical Surgical and Dental Sciences, University of Milan, including patients with JIA and using healthy subjects as controls. Inclusion criteria: aged between 7 and 25 years old at the time of the CBCT examination; Caucasian ethnicity; diagnosis of JIA according to the International League of Associations for Rheumatology (ILAR) criteria documented in patients' records; TMJ involvement; good quality CBCTs covering our region of interest (ROI), from the glabella to the mandibular inferior border; no previous orthodontic/orthopedic treatment; no history of craniofacial trauma or congenital birth defects involving the craniofacial area. Each CBCT scan underwent examination using 3Diagnosys® software. Since data were normally distributed, parametric tests were used for analysis. The sample was divided into three groups: (1) bilateral JIA subjects, (2) unilateral JIA subjects, and (3) healthy controls. Results: We found a statistically significant reduction (p < 0.0001) in the transverse diameter (TR-Diam) of the affected condyles by an average of 1.7 mm, while the axial diameter (AX-Diam) again showed a slight reduction, on average by 0.1 mm, with a non-statistically significant value. Another comparison was made between the unaffected condyles of patients with unilateral JIA and the healthy condyles of the control group. The unilateral unaffected condyles were found to be slightly smaller than those of healthy patients, but without statistically significant differences. We found that in both JIA males and females, the condylar growth tends to stop earlier than the healthy ones. Conclusions: The transverse diameter was found to be more affected than the axial one, causing typical bone resorption and condylar shape. Moreover, we showed that the pathology, in the case of unilateral JIA, does not compromise only the affected condyles; the corresponding condyle that seems to be healthy is actually partially compromised. In addition, we observed that the growth of affected condyles of JIA subjects tends to stop earlier than the condyles of the healthy controls.

Spontaneous Mandibular Dentoalveolar Changes after Rapid Maxillary Expansion (RME), Slow Maxillary Expansion (SME), and Leaf Expander-A Systematic Review.

BACKGROUND: This systematic review aims to analyze the spontaneous dentoalveolar changes in the mandibular arch after maxillary expansion in growing patients obtained with different expansion protocols: Rapid Maxillary Expansion (RME), Slow Maxillary Expansion (SME), and Leaf Expander. METHODS: The study adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Eligibility criteria were established in the PICO format, involving patients who underwent slow, rapid, or leaf maxillary expansion during the mixed or early permanent dentitions. A comprehensive search of electronic databases and manual searches was conducted up to December 2023. The outcome measures included inter-mandibular first permanent molar width, inter-deciduous molar and canine width, arch perimeter, and arch length; both short- and long-term results were considered. The articles that met the inclusion criteria were included in this systematic review and were qualitatively evaluated using a methodological quality scoring system with a 13-point scale. To assess the inter-examiner agreement concerning the article selection and the qualitative assessment of the included studies, Kappa statistics were computed. RESULTS: A total of 1184 articles were identified through electronic and manual searches. After the removal of duplicates and the initial examination of the titles and abstracts, 57 articles were considered for the full text analysis, and according to the eligibility and exclusion criteria, 22 studies were finally selected, composed of 8 randomized controlled trials (RCTs) and 14 retrospective/case-control studies. The qualitative assessment of the included studies showed the following scores: 6 papers have high research quality, 5 have moderate quality, and 11 have low quality. SME demonstrated negligible mandibular changes, with less than 1 mm variation on average (range 0.46-2.00 mm) in the selected parameters and relapses observed in the long term. RME induced more significant increases, particularly in intermolar width greater than 1 mm, which ranged between 0.93 and 3.3 mm, and good stability over the long term. Leaf Expander exhibited promising short-term lower intermolar width increases greater than 1 mm and ranged from 0.5 to 1.69 mm, but long-term stability was not thoroughly evaluated. CONCLUSIONS: SME results in negligible short- and long-term effects, while RME, especially with Haas-type appliances, exhibits significant intermolar width increases that remain stable over the years. Leaf Expander shows short-term lower intermolar width increases, requiring further investigation into long-term stability.

Divergence between CBCT and Optical Scans for Soft Tissue Analysis and Cephalometry in Facial Imaging: A cross-sectional study on healthy adults.

BACKGROUND: Facial soft tissue analysis is becoming increasingly emphasized in orthodontic diagnosis and treatment planning. While traditional cephalometry primarily focuses on hard tissues, recent non-invasive imaging techniques offer the potential to comprehensively evaluate three-dimensional (3D) facial soft tissues. The aim of the study was to establish the geometrical 3D and cephalometric divergence between Cone Beam Computed Tomography (CBCT) derived images and scanned soft tissues. Crucial for enhancing orthodontic diagnosis, minimizing patient exposure to ionizing radiation and providing facial cephalometric parameters. MATERIAL AND METHODS: A cross-sectional study was conducted from January 2020 to May 2023. CBCT and 3D facial scans were obtained simultaneously using a specialized imaging system. Reproducible landmark points were selected for both cephalometric and soft tissue analysis. Angular and linear measurements were recorded, and correlations between CT and facial scans were statistically assessed. RESULTS: Comparisons between 10 CBCT-derived and 10 facial scan-based soft tissue representations resulted into 1.8mm mean root median square (RMS). Angular measurements, such as ANB, right gonial angle, and left gonial angle, exhibited a 0.9° of difference with their respective soft tissue variables. In contrast, linear measurements of total anterior facial height showed a lower correlation coefficient, equal to 0.51. The correlation between soft tissues and underlying hard tissues was more pronounced for gonial angles. CONCLUSION: Facial soft tissue analysis using either 3D facial scans or CBCT-derived offers similar results for orthodontic diagnosis and treatment planning. These findings support the use of non-invasive diagnostic tools in orthodontics, although further investigations are needed to comprehensively understand the complexity of hard and soft tissue relationships.

Soft Tissue Facial Morphology in Growing Patients with Different Occlusal Classes.

INTRODUCTION: The study of facial profiles in the dental field is very important for the diagnosis and the dental and orthodontic treatment plan. The aim of this study is to analyze the three-dimensional morphology of the faces of 269 growing patients with Class I and II occlusions, focusing on children aged between 6 and 9 years old. The analysis was conducted using a non-invasive computerized system, which allowed for the automatic collection of facial landmarks and the subsequent reconstruction of three-dimensional coordinates. MATERIALS AND METHODS: The sample comprised 269 children within the specified age range. Each child's facial features were captured using the non-invasive computerized system, which utilized two infrared CCD cameras, real-time hardware for label recognition, and software for three-dimensional landmark reconstruction. Sixteen cutaneous facial landmarks were automatically collected for each participant. From these landmarks, 10 angular and 15 linear measurements, as well as five direct distance rates, were derived. The mean values for each age class were calculated separately for children with bilateral Angle Class I occlusion and compared with those for children with bilateral Class II occlusion. In all children, the left and right occlusal classes were measured as suggested by Katz. RESULTS: The analysis revealed notable differences, primarily in the three-dimensional angular measurements between children with Class I and II occlusions. Specifically, Class II children exhibited more convex faces in the sagittal plane and a less prominent lower jaw compared to Class I children. However, no significant differences were observed in linear measurements, except for the lower facial height rate, which varied inconsistently across age groups between the two occlusion types. DISCUSSION AND CONCLUSIONS: the findings of this research highlight distinct three-dimensional facial morphological differences between children with Class I and II occlusions. While Class II children tended to have more convex facial profiles and less prominent lower jaws, linear measurements showed minimal variation between the two occlusion types. These results underscore the importance of three-dimensional analysis in understanding facial morphology in growing patients with different occlusal patterns.

Presurgical orthodontic planning: predictability.

The success of orthognathic surgery depends upon the anatomical details of the patient, the direction and extent of the necessary displacement, the experience of the surgical and orthodontic team, and the precision of presurgical orthodontic planning. The authors describe an experimental protocol to optimize presurgical orthodontic planning by the study of linear and rotational discrepancies of skeletal structures. Rotational changes of the skeletal structures can result in an overestimation or underestimation of linear discrepancies. Moreover, teeth can interfere with rotational movements, complicating presurgical planning.The study sample was a group of 20 adult patients, 7 males and 13 females. The inclusion criterion was adult patients who required correction of skeletal asymmetric class II or III malocclusion by osteotomy. Movements in the horizontal, frontal, and midsagittal planes can be simulated and measured through model surgery after diagnostic wax-up of the orthodontic treatment objective. Orthodontic presurgical preparation can be verified through the use of an occlusal splint, which represents a reliable guide during orthodontic preparation. The presurgical orthodontic phase can be obtained in less time and with more accuracy using this treatment planning method and indirect bonding of the orthodontic appliances.

Three-dimensional evaluation of the maxillary sinus in patients with different skeletal classes and cranio-maxillary relationships assessed with cone beam computed tomography.

The objective was to evaluate the relationship between the dimensions of the maxillary sinuses (MSs) and various cephalometric parameters. MS volume (MSV), MS surface (MSS), linear maximum depth (LMD), linear maximum width (LMW), and linear maximum height (LMH) were calculated on CBCT scans of 99 adults. Two sets of two-way (ANOVA) assessed the influence respectively of ANB and SNA angles and of the gender on MS dimensions. Pearson's correlation was calculated between MS dimensions and different cephalometric variables. Reliability and accuracy of the proposed method was tested with intra-operator and inter-operator intraclass correlation coefficient (ICC). Two-way ANOVA showed no statistically significant difference in MSV, MSS and LMH between ANB groups, whilst males were associated with bigger sinuses. LMW showed statistically significant difference in both ANB and gender groups. LMD showed no statistically significant difference. The second Two-way ANOVA showed significantly larger MSV, MSS and LMD in patients with increased or reduced SNA angle but not between genders. LMW and LMH also showed a significant difference between genders. All linear measurements showed a significant interaction of the two factors. The intra-observer and inter-observer ICC scored high for all the tested measurements. MSV and MSS showed a positive correlation with S-N, PNS-A, S-Go, N-Me, N-Ans and the distance between Mx points. LMW had a negative correlation with Ba-S-N angle and N-Me, LMH with Ba-S-N angle, S-Go and Mx r-Mx l and LMD with N-Me and N-ANS. LMW had a positive correlation with Mx r-Mx l, LMH with S-N, S-N^Ans-Pns, N-Me, N-Ans and LMD with S-N, Ba-S-N, PNS-A, S-Go and distance between Mx points. In conclusion, MSV and MSS did not differ between the three skeletal classes, males showed significantly larger MS than in females. Concerning the influence of the cranio-maxillary relationship (SNA) and gender on MS dimension, subjects with a retrusion (SNA < 80°) or protusion (SNA > 84°) of the maxillary alveolar bone had larger MSV, MSS, LMW, LMH and LMD than subjects with a normal cranio-maxillary relationship (SNA 82 ± 2°). A statistically significant high positive correlation was observed between S-N, Pns-A, S-Go, Mx-R/Mx-r and MS dimension. Further studies that evaluate similar outcomes in different races may be able to enrich our knowledge on this topic.

Evaluation of Masticatory Muscles in Adult Patients with Maxillary Hypoplasia Treated with Surgically Assisted Rapid Maxillary Expansion (SARME): A Retrospective Study.

Aim: The aim of the present study was to investigate modifications in electromyographic activity of temporal and masseter muscles before and after surgically assisted rapid maxillary expansion (SARME) in adult subjects. Materials and Methods: Data from 20 patients with unilateral posterior crossbite were selected retrospectively from the Orthodontics Department of the University of Genoa and the Department of Biomedical Surgical and Dental Sciences of the University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico Milan. Inclusion criteria were set as skeletal class I; adult patients (age > 18); good general health; patients with a transverse maxillary deficiency with unilateral posterior crossbite and maxillary constriction ≥ 5 mm; Superficial electromyographic (EMG) examinations at T0 and T1. Exclusion criteria were smoking, metabolic bone diseases (e.g., hyperparathyroidism, vitamin C deficiency), chronic use of corticoids before or during treatment, parafunctional habits (e.g., bruxism), and temporomandibular joint dysfunction. The Shapiro−Wilk test was performed to check whether the data were normally distributed. Differences for each variable before and after SARME were analyzed with a paired t-test (p < 0.05). Results: The statistical analysis demonstrated no statistically significant differences between the EMG values taken before and after SARME regarding the standardized electrical activity of the masticatory muscles (masseter and anterior temporalis (p > 0.05)). Conclusions: Considering the specific conditions of this study, it can be concluded that SARME did not alter the EMG activity of the masseter and temporal muscles. The present study has shown that the masticatory musculature evaluated after approximately 8 months of therapy can adapt well to SARME.

Dentoskeletal effects of clear aligner vs twin block-a short-term study of functional appliances.

PURPOSE: The twin block (TB) is one of the most widely used functional appliances for the correction of class II malocclusions. Align Technology (San Jose, CA, USA) developed the Invisalign® mandibular advancement (MA) that replicates the mechanism of action of a functional appliance. The aim of this study was to compare the changes produced by the TB versus those by MA. METHODS: The records of 56 class II patients treated with the TB (TB group: n = 35) or the MA (MA group: n = 21) were compared to a control sample of 15 untreated class II subjects (UC2). RESULTS: The TB and MA groups showed a significant reduction of the ANB angle, compared to the controls (TB group: -1.5°; MA group: -1.5°; UC2 group: +0.2°). For the Co-Gn values, the TB and MA groups showed significant differences when compared with the UC2 group with an increase of 8.4 mm in TB patients and of 8.3 mm in MA patients. The increase of the distance of Pg to the true vertical line (TVL) was the only measurement where significant differences between the three groups were found with a greater advancement of the soft tissue pogonion in the TB group compared with the MA group and the UC2 group (TB group: +3 mm; MA group: +0.9 mm; UC2 group: -1.6 mm). The angle between the palatal plane and mandibular plane revealed a more relevant reduction in the TB and MA groups. Both appliances were able to reduce overjet and vertical overbite values. CONCLUSIONS: Treatment with the MA and TB appliances produced a significant elongation of the mandible with an improvement in sagittal relationship, overjet, and vertical overbite and with good control of the vertical relationship. TB subjects showed a greater advancement of the soft tissue chin.