3D Cephalometric Normality Range: Auto Contractive Maps (ACM) Analysis in Selected Caucasian Skeletal Class I Age Groups

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.

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.

Three-Dimensional Analysis of the Cranial Base Structure in Patients with Facial Asymmetry

Facial asymmetry is often seen in patients with skeletal mandibular prognathism and is associated with deformities in the maxillofacial and head regions. The maxillofacial deviation is three-dimensional and affects not only the lateral deviation of the mandible and midface, but also the cranium. This study conducted a three-dimensional morphological evaluation of the cranial base morphology of patients with skeletal mandibular prognathism (ANB < 0°, Wits < 0 mm) with the aim of examining the relationship between deformities of the head region and facial asymmetry. Data obtained from computed tomography conducted during the initial examination of patients with and without skeletal mandibular prognathism with facial asymmetry were used. Differences in the position of structures present in the cranial base were measured, and the association between cranial deformities and mandibular deviation was assessed. The middle cranial base area and the lateral deviation of the mandibular fossa were significantly larger in patients with facial asymmetry compared to those without facial asymmetry. In addition, a correlation between the amount of mandibular deviation and the area of the anterior cranial base was identified in patients with significant cranial deformity (p = 0.012). Given the identified association between the structure of the head region and facial asymmetry, further studies are needed to determine the factors implicated in the growth process.

Artificial Intelligence and Its Clinical Applications in Orthodontics: A Systematic Review

This review aims to analyze different strategies that make use of artificial intelligence to enhance diagnosis, treatment planning, and monitoring in orthodontics. Orthodontics has seen significant technological advancements with the introduction of digital equipment, including cone beam computed tomography, intraoral scanners, and software coupled to these devices. The use of deep learning in software has sped up image processing processes. Deep learning is an artificial intelligence technology that trains computers to analyze data like the human brain does. Deep learning models are capable of recognizing complex patterns in photos, text, audio, and other data to generate accurate information and predictions.

MATERIALS AND METHODS

Pubmed, Scopus, and Web of Science were used to discover publications from 1 January 2013 to 18 October 2023 that matched our topic. A comparison of various artificial intelligence applications in orthodontics was generated.

RESULTS

A final number of 33 studies were included in the review for qualitative analysis.

CONCLUSIONS

These studies demonstrate the effectiveness of AI in enhancing orthodontic diagnosis, treatment planning, and assessment. A lot of articles emphasize the integration of artificial intelligence into orthodontics and its potential to revolutionize treatment monitoring, evaluation, and patient outcomes.

Investigating the Relationship between the Dimensions and Morphology of Sella Turcica with the Long-Face Growth Pattern and the Vertical Growth Pattern

Introduction

The sella turcica is one of the important landmarks of lateral cephalometry, which is used in orthodontics for the diagnosis, treatment plan, and evaluation of skeletal development and maturity. The purpose of the present study is to investigate the relationship between the dimensions and morphology of sella turcica with the long-face growth pattern and people with an open bite. This study also examines the relationship between sella turcica bridging (STB) and the vertical growth pattern.

Methods

As many as 153 radiographs were analyzed using the Romexis software, considering the basal, gonial, and FMA angles to determine the vertical growth pattern of the face. The basal angle was also used to check for an open bite. Of these patients, 80 had a long vertical face growth pattern, and 73 had a normal face growth pattern. The four landmarks of tuberculum sellae, dorsum sellae, sellae floor, and posterior clinoid were determined on the cephalograms to measure the length, depth, and anteroposterior diameter of the sella turcica.

Results

In this study, it was found that the chance of developing a long face in people with partial and complete bridging is 8.37 and 1.92, respectively. An increase in the length of the sella turcica for one unit decreases the chance of a long face, and as the depth of the sella turcica increases, the chance of a long face increases.

Conclusions

STB is frequently seen in people with long faces. However, this finding should be considered in relation to other diagnostic parameters. The shorter the length and higher the depth of sella turcica, the higher the chance of developing a long face.

Cross Sectional Analysis of Eurasian Skull Anatomy for 3D Cephalometry-Normative Data Reveal Four Different Skull Types

The unsolved problem in three-dimensional surgical planning for patients with facial deformity, dysgnathia, or asymmetry is the lack of a normative database of "norm skulls" that can be used as treatment objectives. A study was conducted on 90 Eurasian persons (46 male and 44 female adults) for whom cone beam-computed tomography images were available. Inclusion criteria were adult patients with a skeletal Class I pattern, proper interincisal relationship with normal occlusion, the absence of an open bite both in the anterior and posterior region, and a normal and balanced facial appearance; patients with dysgnathia and malformations were excluded. A total of 18 landmarks were digitized and 3D cephalometric measurements were performed and analyzed by means of proportions calculated from the landmarks. Male and female skulls were analyzed, as well as subdivisions revealed by cluster analysis. The data showed that four subtypes of skulls were distinguishable with statistical significance (p < 0.05). A male and a female type subdivided in a brachiocephalic and dolichocephalic phenotype could be identified. For each type, a mean shape was calculated by a Procrustes transformation, which, in turn, was used to create four template skulls from a male and a female skull. This was accomplished by fitting the polygon models of the two skulls to each of the two subtypes based on the landmarks marked on them using a thin plate spline transformation. The normative data of the subtypes can individually serve as a guide for orthodontic surgery in the Eurasian population, which is especially helpful in 3D planning and the execution of craniofacial operations.

Accuracy of automated 3D cephalometric landmarks by deep learning algorithms: systematic review and meta-analysis

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.

Strontium Ranelate Inhibits Osteoclastogenesis through NF-κB-Pathway-Dependent Autophagy

Strontium ranelate (SR) is a pharmaceutical agent used for the prevention and treatment of osteoporosis and fragility fracture. However, little attention has been paid to the effect of SR on alveolar bone remodeling during orthodontic tooth movement and its underlying mechanism. Here, we investigated the influence of SR on orthodontic tooth movement and tooth resorption in Sprague–Dawley rats and the relationship between the nuclear factor–kappa B (NF-κB) pathway, autophagy, and osteoclastogenesis after the administration of SR in vitro and in vivo. In this study, it was found that SR reduced the expression of autophagy-related proteins at the pressure side of the first molars during orthodontic tooth movement. Similarly, the expression of these autophagy-related proteins and the size and number of autophagosomes were downregulated by SR in vitro. The results also showed that SR reduced the number of osteoclasts and suppressed orthodontic tooth movement and root resorption in rats, which could be partially restored using rapamycin, an autophagy inducer. Autophagy was attenuated after pre-osteoclasts were treated with Bay 11-7082, an NF-κB pathway inhibitor, while SR reduced the expression of the proteins central to the NF-κB pathway. Collectively, this study revealed that SR might suppress osteoclastogenesis through NF-κB-pathway-dependent autophagy, resulting in the inhibition of orthodontic tooth movement and root resorption in rats, which might offer a new insight into the treatment of malocclusion and bone metabolic diseases.

Morphological Study of the Mandibular Lingula and Antilingula by Cone-Beam Computed Tomography

The patterns of the lingula and antilingula are crucial surgical reference points for ramus osteotomy. Cone-beam computed tomography (CBCT) provides three-dimensional images, and patient radiation dose is significantly lower for CBCT than for medical CT. The morphology of the mandibular lingula and antilingula of ninety patients (180 sides) were investigated using CBCT. The lingula were classified as having triangular, truncated, nodular, and assimilated shapes. The antilingula were classified as having hill, ridge, plateau, and plain shapes. The patients' sex, skeletal patterns (Classes I, II, and III), and right and left sides were recorded. The most to least common lingula shapes were nodular (37.8%), followed by truncated (32.8%), triangular (24.4%), and assimilated (5%). The most to least common antilingulae were hill (62.8%), plain (18.9%), plateau (13.9%), and ridge (4.4%) patterns, respectively. The lingula and antilingula had identical patterns on both sides in 47 (52.2%) and 46 patients (51.1%), respectively. Sex and skeletal pattern were not significantly correlated to lingula and antilingula shapes. No significant correlation was observed between lingula and antilingula shapes.

Arduino Automated Microwave Oven for Tissue Decalcification

Decalcification of hard tissues such as bone and teeth is a complex process that requires using chemicals such as acids and chelating agents. Acids act faster than chelating agents, but they have a greater risk of damaging biological samples. Increasing the reaction speed of the chelating agent may solve this issue. There are several strategies to speed up this process, and using microwaves seems to be one of the most effective. However, lab-dedicated microwave ovens are expensive, and their purchase may seem unjustified. Therefore, a low-cost modification of a commercial microwave oven, consisting of an Arduino automation device, has been developed. The setup has proven reliable for continuous work, thanks to implementing an electronic safety circuit. In addition, it may reduce the decalcification time using a chelating agent, achieving optimal results regarding tissue preservation and quality of histological sections.

Three-dimensional cephalometric outcome predictability of virtual orthodontic-surgical planning in surgery-first approach

OBJECTIVES

The aim of this study is to introduce a novel 3D cephalometric analysis (3DCA) and to validate its use in evaluating the reproducibility of virtual orthodontic-surgical planning (VOSP) in surgery-first approach (SF) comparing VOSP and post-operative outcome (PostOp).

METHODS

The cohort of nineteen patients underwent bimaxillary orthognathic surgery following the VOSP designed in SimPlant O&O software by processing cone-beam computed tomography (CBCT) scans and intraoral digital scanning of the dental arches. Said records were re-acquired once the post-operative orthodontic treatment was completed. The 3DCA was performed by three expert operators on VOSP and PostOp 3D models. Descriptive statistics of 3DCA measures were evaluated, and outcomes were compared via Wilcoxon test.

RESULTS

In the comparison between cephalometric outcomes against planned ones, the following values showed significant differences: Wits Index, which suggests a tendency towards skeletal class III in PostOp (p = 0.033); decreased PFH/AFH ratio (p = 0.010); decreased upper incisors inclination (p < 0.001); and increased OVJ (p = 0.001). However not significant (p = 0.053), a tendency towards maxillary retroposition was found in PostOp (A/McNamara VOSP: 5.05 ± 2.64 mm; PostOp: 4.1 ± 2.6 mm). On average, however, when McNamara's plane was considered as reference, a tendency to biprotrusion was found. Upper incisal protrusion was greater in PostOp as an orthodontic compensation for residual maxillary retrusion (VOSP: 5.68 ± 2.56 mm; PostOp: 6.53 ± 2.63 mm; p = 0.084). Finally, the frontal symmetry in relation to the median sagittal plane decreased in craniocaudal direction.

LIMITATIONS

A potential limit of studies making use of closest point distance analysis is represented by the complexity that surgeons and orthodontists face in applying this three-dimensional evaluation of SF accuracy/predictability to everyday clinical practice and diagnosis. Also, heterogeneity and limited sample size may impact the results of the study comparison.

CONCLUSIONS

The presented 3DCA offers a valid aid in performing VOSP and analysing orthognathic surgery outcomes, especially in SF. Thanks to the cephalometric analysis, we found that surgery-first approach outcome unpredictability is mainly tied to the sagittal positioning of the maxilla and that the transverse symmetry is progressively less predictable in a craniocaudal direction.

Clinical Performance Evaluation of a Hyaluronic Acid Dental Gel for the Treatment of Traumatic Ulcers in Patients with Fixed Orthodontic Appliances: A Randomized Controlled Trial

BACKGROUND

A newly available gel containing hyaluronic acid (HA) and polyvinylpyrrolidone was tested for efficacy on traumatic oral ulcers (TOU) caused by fixed orthodontic appliances.

METHODS

A double-blind RCT was conducted to test the new gel versus a placebo. According to the sample size calculation, a total of 60 patients were considered sufficient and randomly allocated to one of the two groups out of a pool of 100 total patients who initially agreed to participate in the study. A VAS scale test and lesion measurements at T0, T1, and T2 were performed on the patients.

RESULTS

A total of 70 patients developed TOU, with 8 drop-outs; the intergroup comparison showed a statistically significant greater dimension of the lesion in the control group at T2 when compared to the test group. The pain experienced by the patients belonging to the test group was significantly lower than the pain in the patients in the control group Conclusions: Under the limitations of the study, the new formula might provide faster healing with less pain experienced by the patient when compared to a placebo.

Geometrical Approaches for the Accurate Identification of Normal Vertical Positions of Sella and Nasion Points in Cephalograms

OBJECTIVE

The aim of the study is to identify the normal vertical positions of sella (S) and nasion (N) points in subjects with a normal inclination of anterior cranial bases.

MATERIALS AND METHODS

Lateral cephalograms of 117 subjects who had a normal ∠SN-FH plane (7° ± 1°), ∠SN-palatal plane (9° ± 2°), ∠FH-palatal plane (1° ± 1°), and cranial base angles (131° ± 4°) were included in the study. Various linear and angular parameters and ratios were evaluated to determine the normal vertical positions of S and N points. An unpaired t-test was used to identify any significant differences between males and females. The P value of 0.05 was considered as the level of significance.

RESULTS

Among subjects with the normal inclinations of SN, FH, and palatal planes and cranial base angle, the mean values of ∠Ar-S-Ptm, ∠S-Ptm-Ar, and ∠S-Ar-Ptm were 59.38° ± 3.52°, 59.70° ± 3.21°, and 60.84° ± 3.56°, respectively, forming an almost equilateral triangle between S, Ar, and Ptm points. The mean values of ∠Ba-S-PNS, ∠S-PNS-Ba, and ∠S-Ba-PNS were 59.56° ± 3.17°, 59.72° ± 3.47°, and 60.76° ± 3.11°, respectively, forming another approximate equilateral triangle between S, Ba, and PNS points. The mean S-FH to N-FH ratio was 0.67 ± 0.06% for the whole sample, but it was significantly greater in males (0.69 ± 0.07%) compared to females (0.65 ± 0.06%) (P=0.002).

CONCLUSIONS

Two approximate equilateral triangles were formed between S, Ar, and Ptm points; and S, Ba, and PNS points in subjects with normal inclinations of SN, FH, and palatal planes and cranial base angle. The S-FH to N-FH ratio was an excellent guide to locating the normal vertical position of S and N points.

A Retrospective Study Comparing Nose, Lip, and Chin Morphology in Class I, Class II, and Class III Skeletal Relationships in Patients Visiting to the Department of Orthodontics, BPKIHS: A Cephalometric Study

Background

With the changing paradigm from primarily hard tissue to soft tissue evaluation for orthodontic diagnosis and treatment planning, the priority has shifted to bring about improvement in the profile and smile characteristics of patients. Since not only the esthetics but also the stability of orthodontic treatment is largely determined by the soft tissue envelope, proper positioning of the soft tissue drape becomes paramount. Soft tissues of face, namely, nose, lips, and chin, are of paramount importance not only from an esthetic but also from functional and treatment stability points.

Objective

To determine the morphological variation of lips, nose, and chin in different skeletal malocclusions.

Materials and Methods

Lateral cephalograms of 237 patients visiting the department of orthodontics, BPKIHS, were taken, hand traced on matt acetate tracing paper of 0.002″ thickness with 0.3-mm 2B pencil. Samples were divided into 3 skeletal classes based on ANB angle. Measurements were made in relation to the nose, lips, and chin. Data were inserted in to SPSS and analyzed statistically using descriptive statistics, and mean and standard deviation was calculated for each variable. Multiple comparison between groups was done with post hoc Bonferroni test with mean difference significant at p < 0.05.

Result

On intergroup comparison, a significant difference was found for upper lip thickness (ULT) between Class II and Class III, and lower lip length (LLL) between Class I and Class III, and between Class II and Class III. Significant difference for nasolabial angle (NLA) was found between Class II and Class III. Similarly, a significant difference for the vertical chin parameter (CTV) was found between Class I and Class III, and between Class II and Class III.

Conclusion

Both upper and lower lip thicknesses were highest for Class III followed by Class I and Class II, respectively. Lip lengths too were found to be highest for Class III skeletal relation. Nasolabial angle was larger in Class II malocclusion when compared to Class I and Class III. Similarly, both nasal length and nasal height measurements were in the order of Class III > Class II > Class I. Both horizontal and vertical chin parameters were larger for Class III sagittal relation.

Effects on Muscular Activity after Surgically Assisted Rapid Palatal Expansion: A Prospective Observational Study

The study aims to investigate the modifications in the temporalis and the masseter activity in adult patients before and after SARPE (Surgically Assisted Rapid Palatal Expansion) by measuring electromyographic and electrokinesographic activity. 24 adult patients with unilateral posterior crossbite on the right side were selected from the Orthodontic Department of the University of Milan. Three electromyographic and electrokinesographic surface readings were taken respectively before surgery (T0) and 8 months after surgery (T1). The electromyographic data of both right and left masseter and anterior temporalis muscles were recorded during multiple tests: standardized maximum voluntary contraction (MVC)s, after transcutaneous electrical nerve stimulation (TENS) and at rest. T0 and T1 values were compared with paired Student’s t-test (p < 0.05). Results: Significant differences were found in the activity of right masseter (p = 0.03) and right temporalis (p = 0.02) during clench, in the evaluation of right masseter at rest (p = 0.03), also the muscular activity of masseters at rest after TENS from T0 to T1 (pr = 0.04, pl = 0.04). No significant differences were found in the activity of left masseter (p = 0.41) and left temporalis (p = 0.39) during clench and MVC, in the evaluation of left masseter at rest (p = 0.57) and in the activity during MVC of right masseter (p = 0.41), left masseter (p = 0.34), right temporalis (p = 0.51) and left temporalis (p = 0.77). Results showed that the activity of the masseter and temporalis muscles increased significantly after SARPE during rest and clenching on the side where the cross-bite was treated.