Orthognathic surgery improves compromised natural head position and pharyngeal airway in patients with Skeletal Class II or III malocclusion.

BACKGROUND: Natural head position (NHP), pharyngeal airway and maxillofacial growth pattern are correlated. The author's previous studies proved that following surgical correction of Skeletal Class II malocclusion, the over-extended NHP returned upright, and the pharyngeal airway space (PAS) dimension expanded. OBJECTIVE: The present study compares the post-operative change in NHP and PAS after orthognathic surgery in Skeletal Class II and III malocclusion patients. METHODS: Patients receiving orthognathic procedures to correct Skeletal Class II or III malocclusions were reviewed in this retrospective study. Pre-operative and 6-week post-operative cone-beam computed tomography datasets were collected. Variables representing the craniofacial pattern, the NHP and the PAS were measured three-dimensionally. Post-operative variables were compared with their pre-operative counterparts using either repeat-measure 2-way analysis of variance or Wilcoxon matched-pairs signed rank test. RESULTS: Thirty cases of Skeletal Class II malocclusion and 13 cases of Skeletal Class III malocclusion were collected. Preoperatively, the inter-group differences were significant in craniofacial pattern (68.14 ± 3.552 degree vs. 79.63 ± 2.497 degree, p < .0001) and the NHP (68.77 ± 11.02 degree vs. 82.83 ± 7.738 degree, p = .0002) while not significant in PAS; after surgery, the intergroup differences in craniofacial pattern and the NHP between groups decreased, and the PAS increased in both groups. CONCLUSION: Orthognathic surgery may improve compromised NHP and increase PAS in Skeletal Class II and III malocclusion patients.

Cephalometric Pharyngeal Morphology in Adults with Unoperated Cleft Palate.

OBJECTIVE: The aim of this study was to cephalometrically evaluate the pharyngeal morphology in adults with unoperated Submucous Cleft Palate (SMCP), adults with unoperated Overt Cleft Palate (OCP), and adults without clefts. DESIGN: This study employed a retrospective cross-sectional design. Lateral cephalometric radiography was performed on three groups of adults: 1) 29 with unrepaired SMCP; 2) 41 with unrepaired OCP; and 3) 39 without clefts, who served as controls. One-way ANOVA and rank-sum tests were used for intergroup comparisons. P value was set at .05. RESULTS: The soft palate length and the ratio of soft palate length to pharyngeal depth were significantly lower in subjects with unoperated SMCP and OCP than in non-cleft controls. Significant differences were also observed in pharyngeal depth, nasopharyngeal depth, and posterior pharyngeal wall thickness between subjects with unoperated OCP and non-cleft controls. CONCLUSIONS: Pharyngeal morphology differs significantly between individuals with and without clefts, particularly in soft palate length and the ratio of soft palate length to pharyngeal depth.

Exploratory analysis of new craniometric measures for the investigation of biological sex using open-access statistical and machine-learning tools on a cone-beam computed tomography sample.

Investigation of the biological sex of human remains is a crucial aspect of physical anthropology. However, due to varying states of skeletal preservation, multiple approaches and structures of interest need to be explored. This research aims to investigate the potential use of distances between bifrontal breadth (FMB), infraorbital foramina distance (IOD), nasal breadth (NLB), inter-canine width (ICD), and distance between mental foramina (MFD) for combined sex prediction through traditional statistical methods and through open-access machine-learning tools. Ethical approval was obtained from the ethics committee, and out of 100 cone beam computed tomography (CBCT) scans, 54 individuals were selected with all the points visible. Ten extra exams were chosen to test the predictors developed from the learning sample. Descriptive analysis of measurements, standard deviation, and standard error were obtained. T-student and Mann-Whitney tests were utilized to assess the sex differences within the variables. A logistic regression equation was developed and tested for the investigation of the biological sex as well as decision trees, random forest, and artificial neural networks machine-learning models. The results indicate a strong correlation between the measurements and the sex of individuals. When combined, the measurements were able to predict sex using a regression formula or machine learning based models which can be exported and added to software or webpages. Considering the methods, the estimations showed an accuracy rate superior to 80% for males and 82% for females. All skulls in the test sample were accurately predicted by both statistical and machine-learning models. This exploratory study successfully established a correlation between facial measurements and the sex of individuals, validating the prediction potential of machine learning, augmenting the investigative tools available to experts with a high differentiation potential.

Automatic cephalometric landmark identification with artificial intelligence: An umbrella review of systematic reviews.

OBJECTIVES: The transition from manual to automatic cephalometric landmark identification has not yet reached a consensus for clinical application in orthodontic diagnosis. The present umbrella review aimed to assess artificial intelligence (AI) performance in automatic 2D and 3D cephalometric landmark identification. DATA: A combination of free text words and MeSH keywords pooled by boolean operators: Automa* AND cephalo* AND ("artificial intelligence" OR "machine learning" OR "deep learning" OR "learning"). SOURCES: A search strategy without a timeframe setting was conducted on PubMed, Scopus, Web of Science, Cochrane Library and LILACS. STUDY SELECTION: The study protocol followed the PRISMA guidelines and the PICO question was formulated according to the aim of the article. The database search led to the selection of 15 articles that were assessed for eligibility in full-text. Finally, 11 systematic reviews met the inclusion criteria and were analyzed according to the risk of bias in systematic reviews (ROBIS) tool. CONCLUSIONS: AI was not able to identify the various cephalometric landmarks with the same accuracy. Since most of the included studies' conclusions were based on a wrong 2 mm cut-off difference between the AI automatic landmark location and that allocated by human operators, future research should focus on refining the most powerful architectures to improve the clinical relevance of AI-driven automatic cephalometric analysis. CLINICAL SIGNIFICANCE: Despite a progressively improved performance, AI has exceeded the recommended magnitude of error for most cephalometric landmarks. Moreover, AI automatic landmarking on 3D CBCT appeared to be less accurate compared to that on 2D X-rays. To date, AI-driven cephalometric landmarking still requires the final supervision of an experienced orthodontist.

Argentine reference charts for head circumference from birth to 19 years of age. / Referencias argentinas de perímetro cefálico desde el nacimiento hasta los 19 años.

Introduction. Head circumference (HC) is an indicator of brain growth; growth charts are necessary to determine normal or pathological variations. Objectives. To present the first Argentine HC reference charts between birth and 19 years of age and to compare them with the Nellhaus charts, which have been used in our country to date. Population and methods. These references were developed based on combined data from the National Survey on Nutrition and Health of 2018 and cross-sectional studies conducted between 2004 and 2007 in the provinces of Buenos Aires and La Pampa, which included 8326 healthy children and adolescents. Growth curves were adjusted using the LMS method. To assess the differences between these reference charts and the Nellhaus charts, at different ages, the 2nd, 50th, and 98th percentiles were plotted. Results. HC showed a variable increase in size with age, which was greater in the first years of life, and a slight increase at puberty. The values for the 98th percentile of the Argentine reference charts werehigher than those of the Nellhaus charts at all ages. The values for the 2nd percentile of the national reference were lower than those of the Nellhaus charts during the first 2 years of life, similar between 3 and 7 years of age, and higher after this age. Conclusions. The Argentine curves adequately describe the growth pattern of HC. The differences found with the Nellhaus charts may be attributed to secular changes.

Introducción. El perímetro cefálico (PC) es un indicador del crecimiento cerebral y es necesario contar con referencias de crecimiento que permitan determinar variaciones normales o patológicas. Objetivos. Presentar las primeras referencias argentinas de perímetro cefálico entre el nacimiento y los 19 años, y compararlas con las referencias de Nellhaus, utilizadas en nuestro país hasta la actualidad. Población y métodos. Para la construcción de estas referencias, se combinaron datos de la Encuesta Nacional de Nutrición y Salud 2018 y estudios transversales realizados entre 2004 y 2007 en las provincias de Buenos Aires y La Pampa, que incluyeron 8326 niños, niñas y adolescentes sanos. Las curvas de crecimiento fueron ajustadas con el método LMS. Para evaluar la magnitud de las diferencias entre estas referencias y las de Nellhaus, a diferentes edades, se graficaron los centilos 2, 50 y 98. Resultados. El PC mostró un incremento de tamaño variable con la edad, de mayor magnitud en los primeros años de vida, y un ligero incremento en la pubertad. Los valores del centilo 98 de las referencias argentinas fueron mayores que los de Nellhaus en todas las edades. Los valores del centilo 2 de la referencia nacional fueron menores que los de Nellhaus durante los primeros 2 años de vida, similares entre los 3 y 7 años, y mayores a partir de esta edad. Conclusiones. Las curvas argentinas describen adecuadamente el patrón de crecimiento del PC. Las diferencias halladas con la referencia de Nellhaus pueden atribuirse a cambios seculares.

Cephalometric Screening Assessment for Superior Airway Space Narrowing-Added Value of Three-Dimensional Imaging.

Background: Assessing the morphology of the superior airway space is a crucial diagnostic step in the treatment planning of patients with obstructive sleep apnea syndrome (OSAS) or prior to orthognathic surgery. The aim of this study is to evaluate the necessary scope of a two-dimensional cephalometric assessment and the necessity of three-dimensional imaging in the identification of superior airway space narrowing (SASN). Methods: The computed tomography studies of 100 non-obese, non-OSAS patients were evaluated and analyzed retrospectively. Multiplanar reconstructions were created and underwent cephalometric evaluation. The three-dimensional superior airway morphology was segmented and measured for the minimal cross-sectional area (Amin) and volume (V0). Patients were grouped according to Amin < 80 mm2 and V0 < 12 cm3. Cephalometric parameters (CPs) were analyzed according to Amin and V0 with an unpaired t-test, Pearson correlation, and ROC-curve analysis. Results: The CPs regarding sagittal airway space dimensions (IPAS, MPAS, SPAS) and mandibular body length (GoGn) show the strongest correlation to the three-dimensional minimal cross-sectional area (Amin). The ROC-curve analysis classifying for SASN led to an AUC of 0.86 for IPAS, 0.87 for MPAS, 0.88 for SPAS, and 0.63 for GoGn. Three-dimensional imaging may further improve the diagnostic accuracy in the identification of SASN for IPAS below 13.5 mm, MPAS below 10.2 mm, SPAS below 12.5 mm, and GoGn below 90.2 mm. Conclusions: Two-dimensional cephalometric sagittal airway space diameters and mandibular body length are useful initial screening parameters in the identification of superior airway space narrowing. Nevertheless, as the correlation of two-dimensional cephalometric parameters with three-dimensional upper airway space narrowing is varying and highly dependent on acquisition circumstances, indications for three-dimensional imaging, if possible, in the supine position to evaluate upper airway space morphology should be provided generously, especially in patients with low but normal airway space parameters in two-dimensional cephalometry.

Prediction of surgery-first approach orthognathic surgery using deep learning models.

The surgery-first approach (SFA) orthognathic surgery can be beneficial due to reduced overall treatment time and earlier profile improvement. The objective of this study was to utilize deep learning to predict the treatment modality of SFA or the orthodontics-first approach (OFA) in orthognathic surgery patients and assess its clinical accuracy. A supervised deep learning model using three convolutional neural networks (CNNs) was trained based on lateral cephalograms and occlusal views of 3D dental model scans from 228 skeletal Class III malocclusion patients (114 treated by SFA and 114 by OFA). An ablation study of five groups (lateral cephalogram only, mandible image only, maxilla image only, maxilla and mandible images, and all data combined) was conducted to assess the influence of each input type. The results showed the average validation accuracy, precision, recall, F1 score, and AUROC for the five folds were 0.978, 0.980, 0.980, 0.980, and 0.998 ; the average testing results for the five folds were 0.906, 0.986, 0.828, 0.892, and 0.952. The lateral cephalogram only group had the least accuracy, while the maxilla image only group had the best accuracy. Deep learning provides a novel method for an accelerated workflow, automated assisted decision-making, and personalized treatment planning.

Accuracy of Gonial Angle Measurements Using Panoramic Imaging versus Lateral Cephalograms in Adults with Different Mandibular Divergence Patterns.

Introduction: Gonial angle is an important craniofacial parameter providing information about symmetry and vertical dimensions of the facial skeleton. It can be measured on panoramic radiographs and lateral cephalograms. Reliable assessment of the gonial angle is challenged by the superimpositions associated with lateral cephalograms. The aim of the current study was to assess the precision of panoramic imaging in measuring the gonial angles compared to lateral cephalograms in adult patients with different mandibular divergence patterns. Methods: Panoramic radiographs and lateral cephalograms of 448 adults (18-30 years old) were utilized in the study. The gonial angle was determined on the lateral cephalograms using an online AI-driven assessment tool (WebCephTM) and compared to the panoramic measurements among the different gender, malocclusion, and mandibular divergence groups. Results: Statistically significant differences were recorded between measurements taken on lateral cephalograms or panoramic radiographs (p=0.022). In addition, statistically significant differences were reported in gonial angle measurements on panoramic radiographs among the different mandibular divergence groups (p=0.004) for FMA (p=0.002) for Sn-GoMe. Conclusion: While cephalometry is considered the gold standard tool for reliable gonial angle assessment, panoramic radiographs were more accurate in detecting the differences between the divergence groups in the current study.

Orthognathic surgery: a significant tool for reassessment / La chirurgie orthognathique : un outil à ne pas oublier dans la réévaluation

Introduction: More than 15 years of experience in orthodontic-surgical collaboration has allowed the authors to identify some situations in which a new perspective is needed. Although it may seem easy to refer a patient to a maxillo-facial surgeon in cases of major dysmorphoses, this can lead to yet other dilemmas: a loss of results at the end of a developmental growth stage, an adult requesting a return to treatment after a camouflage orthodontic treatment or a non-cooperative child in an interceptive and preventive treatment phase. Then, a comprehensive process of reassessment becomes compulsory. Material and Method: In the form of an editorial, this article describes various cases encountered in the authors' practice. Discussion: The aim is not to point out the imperfections of our humanity, but simply to open our eyes to diagnostic elements that are missed, whether in the initial phase or during reassessment. Conclusion: As it is far from ideal to keep offering similar therapies that lead to the same pitfalls, it is time for a shift in the paradigm.

Introduction: Plus de 15 ans de recul en collaboration orthodontico-chirurgicale ont permis aux auteurs d'identifier un certain nombre de situations dans lesquelles un regard différent est devenu opportun. S'il est aisé d'orienter un patient vers un(e) chirurgien(ne) maxillo-facial(e) en cas de dysmorphoses majeures, les orthodontistes sont régulièrement confrontés à d'autres dilemmes : une perte de résultat en fin de croissance, un adulte demandeur d'une reprise après un traitement en compensation ou encore un enfant non-coopérant en phase interceptive. Une phase de réévaluation exhaustive devient alors nécessaire. Matériel et méthode: Sous la forme d'un éditorial, cet article expose différentes situations cliniques auxquelles les auteurs ont été confrontés lors de leur pratique. Discussion: Le propos n'est pas de pointer les imperfections de notre humanité mais seulement d'ouvrir les yeux sur des éléments diagnostiques qui échappent, que ce soit en phase initiale ou en réévaluation. Conclusion: Offrir une thérapeutique identique conduisant aux mêmes écueils n'est pas acceptable : il est temps de changer de paradigme.

Predicting optimal patient-specific postoperative facial landmarks for patients with craniomaxillofacial deformities.

Orthognathic surgery primarily corrects skeletal anomalies and malocclusion to enhance facial aesthetics, aiming for an improved facial appearance. However, this traditional skeletal-driven approach may result in undesirable residual asymmetry. To address this issue, a soft tissue-driven planning methodology has been proposed. This technique estimates bone movements based on the envisioned optimal facial appearance, thereby enhancing surgical accuracy and effectiveness. This study investigates the initial implementation phase of the soft tissue-driven approach, simulating the patient's ideal appearance by realigning distorted facial landmarks to an ideal state. The algorithm employs symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are essential in orthognathic surgery for facial aesthetics. It also incorporates regularization to preserve the patient's facial characteristics. Validation through retrospective analysis of preoperative patients and normal subjects demonstrates this method's efficacy in achieving facial symmetry, particularly in the lower face, and promoting a natural, harmonious contour. Adhering to soft tissue-driven principles, this novel approach shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.

Novel Parameter in Pre-Surgical Orthodontic Preparation: A Retrospective Study on the Role of the Upper Incisor Position and a Morphological Evaluation of the Anterior Nasal Spine.

The position and inclination of the incisors play a crucial role in achieving optimal outcomes in orthodontic and orthognathic surgical treatment, given their impact on facial aesthetics. Background/objectives: Due to numerous distorting factors that affect the reliability of the ANB angle, the aim of the present work is to evaluate a more constant parameter over time, the anterior nasal spine (ANS), and explore whether aligning the incisal margin of the upper incisors with the anterior nasal spine could be a reliable indicator for achieving appropriate labial support in pre-surgical orthodontic preparation. Methods: From a pool of 500 cone beam computed tomography (CBCT) scans, 50 CBCT examinations displaying a Class 1 skeletal pattern (ANB = 2° ± 2°) with an intermediate (3.2-4 mm) or mixed (4-6 mm) sagittal maxillary position (MX), as determined by the 3D multiplanar total face approach (TFA), were selected and compared with CBCT examinations randomly chosen from the initial pool. Moreover, 12 landmarks were identified, and measurements were automatically obtained, using software, and recorded. Mean and standard deviation values were calculated for each sample. A comparison was made between the two samples, aligning the results with the morphological analysis of the anterior nasal spine and the sagittal position of the upper maxilla. Results: In Class 1 subjects, the distance between the incisal margin and the plane passed in relation to the anterior nasal spine should range between -1 mm and 1 mm, aligned with or slightly ahead of the anterior nasal spine or slightly ahead of this limit. Conclusions: The anterior nasal spine can serve as a reliable reference point for planning the position of the upper incisors, with excessive proclination or retroclination from this reference point deemed unacceptable.

Effects of an Educational Intervention Program on Positional Cranial Deformity in Premature Infants.

Positional cranial deformities are associated with prematurity evolving during the first 2 years of life due to the malleable characteristics of the skull, the first year being the main/primary therapeutic window for intervention. The objectives were (a) to describe health characteristics, peri- and postnatal pathologies, and positional cranial deformities in infants enrolled in an early intervention program and (b) to analyze the effects of a parent education-based intervention program on positional cranial deformity in premature infants. A quantitative, analytical, longitudinal study was conducted. It included 103 premature infants enrolled in an early intervention program (EIP) during the year 2017, all under 4 months of corrected age, to whom a parent education-based intervention program was applied. Cranial circumference, cranial width, diagonals, and anteroposterior diameter were measured, and the cranial asymmetry index (CAI) and cephalic index (CI) were calculated at baseline and during two subsequent evaluations separated by a 3-month period. The main results showed that 75.7% of the infants belonged to a very premature gestational age category, and 57.3% had an adequate weight for gestational age. The most frequent pathologies were premature jaundice, premature anemia, and hyaline membrane disease. The most frequent positional cranial deformity was plagiocephaly. The parent education-based intervention program resulted in (1) a significant decrease in the CAI and a significant increase in the IC, (2) plagiocephalies: an increase in the mild category and a decrease in the moderate + severe categories, (3) brachycephalies: a decrease in the absence category and an increase in the moderate + severe category, and (4) dolichocephalies: an increase in the absence category and a decrease in the mild category. In conclusion, the recommended first line of intervention was not enough for this population, and future studies should support the development of national clinical guidelines, where education is complemented with other therapeutic measures.

Fully automated landmarking and facial segmentation on 3D photographs.

Three-dimensional facial stereophotogrammetry provides a detailed representation of craniofacial soft tissue without the use of ionizing radiation. While manual annotation of landmarks serves as the current gold standard for cephalometric analysis, it is a time-consuming process and is prone to human error. The aim in this study was to develop and evaluate an automated cephalometric annotation method using a deep learning-based approach. Ten landmarks were manually annotated on 2897 3D facial photographs. The automated landmarking workflow involved two successive DiffusionNet models. The dataset was randomly divided into a training and test dataset. The precision of the workflow was evaluated by calculating the Euclidean distances between the automated and manual landmarks and compared to the intra-observer and inter-observer variability of manual annotation and a semi-automated landmarking method. The workflow was successful in 98.6% of all test cases. The deep learning-based landmarking method achieved precise and consistent landmark annotation. The mean precision of 1.69 ± 1.15 mm was comparable to the inter-observer variability (1.31 ± 0.91 mm) of manual annotation. Automated landmark annotation on 3D photographs was achieved with the DiffusionNet-based approach. The proposed method allows quantitative analysis of large datasets and may be used in diagnosis, follow-up, and virtual surgical planning.

Late-forming supernumerary teeth: A case series.

The aim of this case series was to illustrate the development of late-forming supernumerary teeth (LFST) and highlight the implications for orthodontic treatment. There are limited studies relating to the aetiology, prevalence and treatment of LFST and the cases presented here demonstrate the management of LFST within a tertiary care centre. Five cases are presented, which show various presentations and chronological ages in the development of LFST. This case series emphasises the significance of maintaining a low threshold for suspecting LFST in patients where supernumerary teeth have previously been identified. It also highlights the importance of regular clinical and radiographic reviews. Timely identification can help prevent complications and optimise treatment outcomes.

The relationship between eye canting and vertical craniofacial skeletal asymmetry in adult patients with dento-maxillofacial deformities.

BACKGROUND: Whether eye canting in patients with asymmetric dento-maxillofacial deformities is the result of anatomical asymmetry or a compensatory head position remains controversial. OBJECTIVE: This cross-sectional study aims to verify whether eye canting is correlated with craniofacial skeletal asymmetry. METHODS & MATERIALS: This study was performed by measuring the computed tomographic scans of 223 patients with dento-maxillofacial deformities in Mimics 21.0 software. First grouping was determined based on the intersection angle between the line passing through bilateral lateral canthus point and Frankfurt horizontal plane, and final grouping was based on measurements of the pregroups. RESULTS: The patients were finally categorized into three groups: symmetry group (n = 163), asymmetry subgroups 1 (n = 33) and asymmetry subgroups 2 (n = 27). The results of multiple linear regression and comparisons among groups suggests the presence of orbital skeletal asymmetry in patients with eye canting and the eye canting is partly increment dependent of orbital skeletal asymmetry when using bilateral ears as the reference. The result also reveals that there is a greater angle between the line through bilateral ocular landmarks and the line through the bilateral ear landmarks in patients with ocular canting compared to patient without eye canting. CONCLUSION: Patients with asymmetric dento-maxillofacial deformities and with eye canting have vertical asymmetry of the orbital and cranial skeletal landmarks. These symmetry differences between the eyes and ears may affect the overall craniofacial symmetry after orthognathic surgery.

Comparative Evaluation of Relapse After LeFort 1 Osteotomy in Cleft Palate and Non-cleft Individuals: A Longitudinal Study.

PURPOSE: The aim of this study was to assess and compare the likelihood of relapse one year after LeFort I advancement surgery in patients with and without cleft lip and palate. METHODS: A retrospective observational study which included two groups of participants who underwent LeFort I maxillary advancement was performed. Group 1 included 10 non-cleft subjects and Group 2 included 21 subjects with cleft palate. These maxillary deficient patients were chosen and operated using a technique where only a sagittal displacement was intended. Patients who underwent additional mandibular surgery, significant vertical or transverse alterations, or both were excluded. Pre-operative (T1), immediately post-operative (T2), and minimum one-year follow-up (T3) lateral cephalograms were studied for each group. Skeletal stability and dental stability after LeFort I surgery at a minimum of one-year follow-up in cleft palate and non-cleft patients were evaluated. RESULTS: For the given sample size, relapse tendencies showed statistically significant differences between cleft palate patients and non-cleft palate patients after maxillary advancement. The sella nasion angle and horizontal overlap of the maxillary and mandibular incisors (overjet) decreased by 2 degrees and 0.9 mm respectively in the cleft palate group while decreasing by 1.10 degrees and 0.40 mm in the non-cleft group. CONCLUSIONS: After maxillary advancement with LeFort I osteotomy and miniplate fixation in patients with cleft palate and non-cleft patients, some degree of relapse was detected in both groups for the given sample size after one year post-operatively. The cleft palate group displayed additional relapse tendencies when compared to the non-cleft group.

Cephalometric analysis of patients with beta thalassemia receiving fetal hemoglobin induction therapy.

Objective: We aimed to determine the effects of fetal hemoglobin induction therapy in restricting or even reversing the cephalometric changes associated with beta thalassemia. Materials and methods: In this comparative observational study, 90 participants were equally divided into three groups: a control group; patients with thalassemia major receiving blood transfusion (BT group); and patients receiving induction therapy (i.e., hydroxyl urea (5-10 mg/kg/day) or as much as 20 mg/kg/day) and thalidomide (2-10 mg/kg/day) along with blood transfusion (IT group). All patients underwent history taking and examination, photographic assessment, and radiographic evaluation with a lateral cephalogram. One-way ANOVA followed by post-hoc Tukey test was used to determine differences among groups. Results: The IT group differed significantly from the BT group in all photographic and skull table parameters, and most cephalometric parameters, such as facial angle (p ≤ 0.001), middle and lower facial heights (p ≤ 0.001), and inter-incisal angle (p = 0.036); the mean values in the IT group were similar to those in the control group. In-addition, dental and soft tissue measurements significantly differed among groups. For most parameters, the mean difference indicated higher values in the BT group. Conclusion: Induction therapy appeared to improve the facial angles, heights, and inter-incisal angles, whereas a class II skeletal pattern was observed in the transfusion only group. These findings suggest that fetal hemoglobin induction therapy might have restricted some of the cephalometric changes in patients with beta thalassemia.

Long-term evaluation of condylar positional and volumetric parameters and skeletal stability in Class III bimaxillary orthognathic surgery patients.

This retrospective study examined long-term (4-5 years) condylar positional and volumetric changes and skeletal stability after bimaxillary orthognathic surgery in skeletal Class III patients. Pre-surgical (T0: 0.9 ± 1.1 months) and post-surgical (T1: 0.6 ± 0.7 months; T2: 12.8 ± 3.1 months; T3: 56.5 ± 6.5 months) cone beam computed tomography (CBCT) images of 22 patients were obtained. CBCT multiplanar reformation (MPR) images were generated, and three-dimensional (3D) condylar models were constructed and superimposed to compare changes in condylar volume from pre- to postoperative. Condylar position in the sagittal and coronal planes altered immediately after surgery; however at long-term follow-up, the condyles had returned to their pre-surgical position. The condyles remained slightly inwardly rotated at short-term (-2.6°, 95% confidence interval -3.5° to -1.7°) and long-term (-1.9°, 95% confidence interval -2.8° to -1.0°) follow-up. Changes in condylar volume were insignificant after surgery. Condylar positional changes had no effect on skeletal stability. However, patients with an increased face height prior to surgery and more retrusive jaw position postoperatively were more prone to condylar resorption. Surgical changes remained stable 4-5 years after surgery. In conclusion, condylar position changed insignificantly following surgical correction in Class III patients provided that the correct surgical technique was employed.

Third molar angulation and retromolar space after functional orthodontic treatment : Evaluation of panoramic radiographs after monoblock or Herbst appliance.

PURPOSE: The aim of this respectively cohort study was to evaluate the lower second and third molars and canine angulations, retromolar space and occlusal relationships after functional orthodontic treatments with the monoblock or Herbst appliance using panoramic radiographs. METHODS: Pre- and posttreatment cephalometric and panoramic radiographs of 133 patients (mean age 13.89 ± 1.14 years) treated non-extraction with monoblock (n: 44), Herbst (n: 45) and fixed orthodontic appliances (control group; n: 44) were included to the study. Dental and skeletal measurements were performed on cephalometric radiographs. The angle between the third and second molars, and canines with the lower border of the mandible and the occlusal plane, gonial angle, the angle between the third and second molars and the retromolar space width were assessed on pre- and posttreatment panoramic radiographs. Paired and independent t tests were used for the statistical analysis of the data for intragroup and intergroup comparisons. RESULTS: Functional treatment with both the monoblock and the Herbst appliances resulted in improvement of skeletal class II relationships. Retromolar space significantly increased in the functional appliance groups compared to the control group (p ≤ 0.001), but improvement of the angulations of posterior teeth was significant only in the monoblock group (p ≤ 0.001). CONCLUSION: While both the Herbst and monoblock appliances led to an increase in retromolar space, monoblock treatment resulted in more favorable angulation of the third molars compared to the Herbst treatment.

Accuracy and tracing time of cephalometric analyses on a tablet or desktop computer : A prospective study.

BACKGROUND: This prospective study aimed to evaluate the influence of the computer type (tablet or desktop) on accuracy and tracing time of cephalometric analyses. METHODS: Dental students used a web-based application specifically developed for this purpose to perform cephalometric analyses on tablet and desktop computers. Landmark locations and timestamps were exported to measure the accuracy, successful detection rate and tracing time. Reference landmarks were established by six experienced orthodontists. Statistical analysis included reliability assessment, descriptive statistics, and linear mixed effect models. RESULTS: Over a period of 8 semesters a total of 277 cephalometric analyses by 161 students were included. The interrater reliability of the orthodontists establishing the reference coordinates was excellent (ICC > 0.9). For the students, the mean landmark deviation was 2.05 mm and the successful detection rate for the clinically acceptable threshold of 2 mm suggested in the literature was 68.6%, with large variations among landmarks. No effect of the computer type on accuracy and tracing time of the cephalometric analyses could be found. CONCLUSION: The use of tablet computers for cephalometric analyses can be recommended.