Friction versus frictionless mechanics during maxillary en-masse retraction in adult patients with Class I bimaxillary dentoalveolar protrusion: a randomized clinical trial.

BACKGROUND: Extraction space closure is a challenging phase during orthodontic treatment that affects not only the total treatment duration but also the whole treatment outcome. OBJECTIVE: To compare the efficiency of friction and frictionless mechanics during en-masse retraction of maxillary anterior teeth in adult patients with bimaxillary dentoalveolar protrusion. TRIAL DESIGN: Two-arm parallel group, single-center randomized clinical trial. MATERIALS AND METHODS: Thirty-two adult patients with bimaxillary protrusion were recruited and randomly allocated to two different retraction mechanics. A friction group, using NiTi coil springs and a frictionless group using closing T-loops for en-masse retraction. Randomization in a 1:1 ratio was generated by Microsoft Excel. The randomization numbers were secured in opaque sealed envelopes for allocation concealment. Retraction started in all patients following first premolars extraction using miniscrews as a source of indirect anchorage. Activation was done on a monthly basis until complete retraction of anterior segment. The rate of retraction, amount of anchorage loss, the dental, and soft tissue changes were analyzed on digital models and lateral cephalograms taken before retraction and after space closure. BLINDING: The outcome assessor was blinded through data concealment during assessment. RESULTS: Two patients were lost to follow up, so 30 patients completed the trial. The rate of anterior segment retraction was 0.88 ±â€…0.66 mm/month in the frictionless group compared to 0.72 ±â€…0.36 mm/month in the friction group which was statistically significant. Anchorage loss of 1.18 ±â€…0.72 mm in the friction group compared to 1.29 ±â€…0.55 mm in the frictionless group with no significant difference. Comparable dental and soft tissue changes following en-masse retraction were reported in both groups, with no statistically significant difference. HARM: one patient complained of soft tissue swelling following miniscrew insertion, but the swelling disappeared after one week of using mouth wash. LIMITATION: The study focused only on the maxillary arch. CONCLUSION: Both mechanics have successfully achieved the required treatment objectives in patients with bimaxillary dentoalveolar protrusion. Frictionless group showed a faster rate of retraction than the friction group, which was statistically but not clinically significant. TRIAL REGISTRATION: Clinicaltrials.gov with the identifier NCT03261024.

Dentoalveolar bone height in Class I adults with different vertical patterns: A cross-sectional study.

BACKGROUND: Facial divergence during growth and development affects both the anterior and posterior alveolar bone dimensions in the maxilla and mandible, and the dentoalveolar compensation mechanism in severe vertical skeletal discrepancies remains unclear. AIMS: To evaluate the: (1) difference in dentoalveolar heights among subjects with different vertical facial patterns; (2) association between the dentoalveolar bone height and other cephalometric variables; (3) effect of sex on dentoalveolar height measurements. MATERIAL AND METHODS: Non-growing subjects with skeletal Class I (0°

The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

OBJECTIVE: To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. METHODS: The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. RESULTS: Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). CONCLUSIONS: The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

A comprehensive national survey on malocclusion prevalence among Palestinian children.

BACKGROUND: This study aims to evaluate the prevalence of malocclusion and orthodontic features among schoolchildren in the West Bank, Palestine. METHODS: A stratified cluster sample of 1278 schoolchildren (620 males, 658 females, mean age 12 years and 5 months (± 0.5)) were examined. Candidates who had not received any previous orthodontic treatment were only included. Dental anomalies like missing and ectopic teeth were recorded. The anteroposterior occlusal relationship was assessed based on Angle classification. Overjet and overbite were measured. Crowding and spacing were recorded subjectively. In addition, crossbite, openbite, and midline displacement were recorded. The chi-square test and descriptive analysis were used statistically. RESULTS: The study found Angle Class I molar relationship in 65%, Class II div 1 in 17%, Class II div 2 in 6%, and Class III in 12% of the sample. An overjet (OJ) of more than 4 mm was present in 17%, and 4% had OJ of more than 6 mm; an OJ of at least 0 mm or less in 36%, and 6% had a reverse OJ. A normal overbite was observed in 53%, while 28% had an increase and 19% had a decreased overbite. An anterior openbite (AOB) was present in 9%, and a scissor bite or anterior crossbite in 6% and 14%, respectively. A posterior crossbite was observed in 12% (9% unilateral and 3% bilateral). Midline displacement was found in (9%). Crowding was observed in 35% and 31% and spacing in 24% and 15% of the maxillary and mandibular arches, respectively. A statistically significant relationship between gender and midline shift, a diastema, spacing in the upper arch, and most dental anomalies was found; males were more affected (p < 0.05). CONCLUSION: This study reported a high prevalence of malocclusion among schoolchildren in Palestine. A collaborative effort should be directed to obtain more monitoring and surveillance of malocclusion more frequently to prevent and control the exacerbation of the problem.

Family-based GWAS for dental class I malocclusion and clefts.

BACKGROUND: Individuals born with cleft lip and/or palate who receive corrective surgery regularly have abnormal growth in the midface region such that they exhibit premaxillary hypoplasia. However, there are also genetic contributions to craniofacial morphology in the midface region, so although these individuals appear to have Class III skeletal discrepancy, their molar relationship may be Class I. Past genome-wide association studies (GWASs) on skeletal Class II and III malocclusion suggested that multiple genetic markers contribute to these phenotypes via a multifactorial inheritance model, but research has yet to examine the genetic markers associated with dental Class I malocclusion. Thus, our goal was to conduct a family based GWAS to identify genes across the genome that are associated with Class I malocclusion, as defined by molar relations, in humans with and without clefts. METHODS: Our cohort consisted of 739 individuals from 47 Filipino families originally recruited in 2006 to investigate the genetic basis of orofacial clefts. All individuals supplied blood samples for DNA extraction and genotyping, and a 5,766 single nucleotide polymorphism (SNP) custom panel was used for the analyses. We performed a transmission disequilibrium test for participants with and without clefts to identify genetic contributors potentially involved with Class I malocclusion. RESULTS: In the total cohort, 13 SNPs had associations that reached the genomic control threshold (p < 0.005), while five SNPs were associated with Class I in the cohort of participants without clefts, including four associations that were identified in the total cohort. The associations for the SNPs ABCA4 rs952499, SOX1-OT rs726455, and RORA rs877228 are of particular interest, as past research found associations between these genes and various craniofacial phenotypes, including cleft lip and/or palate. CONCLUSIONS: These findings support the multifactorial inheritance model for dental Class I malocclusion and suggest a common genetic basis for different aspects of craniofacial development.

Facial soft-tissue shape changes after fixed edgewise treatment with premolar extraction in individual artificial-intelligence-classified facial profile patterns.

OBJECTIVE: To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes. METHODS: One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group. RESULTS: Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3. CONCLUSIONS: The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.

Is hand-wrist radiography still necessary in orthodontic treatment planning?

OBJECTIVES: The aim of our study is to compare the relationship between hand-wrist and cervical vertebra maturation stages with chronological age and to investigate the effect of malocclusion type on the relationship between these methods. MATERIALS AND METHODS: Hand-wrist and cephalometric radiographs of 1000 patients (526 females, 474 males) with a mean age of 13.41 ± 1.83 were analyzed. The methods of Bacetti et al. were used for the cervical vertebra maturation stage, and Björk, Grave and Brown's methods were used for the hand-wrist maturation stage. One-way ANOVA test was applied to compare skeletal classes between them. Tukey post hoc test was used to determine the differences. The relationship between the malocclusion type, cervical vertebra and hand-wrist maturation stages was evaluated with the Spearman correlation test. RESULTS: Spearman's correlation coefficient was 0.831, 0.831 and 0.760 in Class I, II and III females, respectively. In males, it was calculated as 0.844, 0.889 and 0.906, respectively. When sex and malocclusion were not differentiated, the correlation was found to be 0.887. All were statistically significant (P < 0.001). The highest correlation was observed in class III males, while the lowest was found in class III females. CONCLUSION: Cervical vertebrae can be used safely to assess pubertal spurt without hand-wrist radiography. Diagnosing growth and development stages from cephalometric images is important in reducing additional workload and preventing radiation risk.

Evaluation of mandibular trabecular bone structure in growing children with Class I, II, and III malocclusions using fractal analysis: A retrospective study.

OBJECTIVE: The present study aimed to evaluate the mandibular bone structure of patients with different malocclusions by using fractal dimension (FD) analysis on dental panoramic radiographic images. MATERIAL AND METHODS: Pre-treatment panoramic radiographic images of 103 patients were included in the study and divided into 3 groups as Class I (group 1: 0

Occlusal contact changes in patients treated with clear aligners: A retrospective evaluation using digital dental models.

INTRODUCTION: This study used digital intraoral scans to evaluate how clear aligner treatment affects occlusal contacts and to determine the influence of sex and age on contact changes. Results were compared with contact changes that occur during fixed appliance therapy. METHODS: Patients included in this study were treated in a University setting and private practice. Inclusion criteria were a Class I malocclusion treated nonextraction with clear aligners and the presence of pretreatment and posttreatment digital intraoral scans. Scans were imported into specialized software, and occlusal contacts were analyzed. The effects of age and sex on contact changes during clear aligner treatment were determined. Changes in occlusal contacts were compared with changes that occur during nonextraction treatment of patients with a Class I relationship using fixed edgewise appliances. RESULTS: A total of 45 clear aligner patients fit the eligibility criteria. Clear aligner treatment reduced the percentage of tight, near, and approximating contacts, whereas the percentage of open and no contacts increased. These changes in occlusal contacts were greater for the older age group studied. Genderinfluenced occlusal contact changes in the anterior dentition only where the decrease in near contacts and increase in open contacts were greater for males. These results for patients treated with clear aligners were similar to those for patients treated with fixed appliances; both treatment modalities reduced close occlusal contacts at the time active treatment was completed. CONCLUSIONS: These results indicated that when clear aligners or fixed appliances are used to treat a Class I malocclusion, the resulting occlusion immediately after debonding is not as "tight" as it was at pretreatment.

Digital setup accuracy for moderate crowding correction with fixed orthodontic appliances: a prospective study.

OBJECTIVES: To evaluate the accuracy of a semi-automatic 3D digital setup process in predicting the orthodontic treatment outcome achieved by labial fixed appliances. SUBJECTS AND METHODS: Twenty-five adult patients (18 to 24 years old) with class I malocclusion and moderate crowding were prospectively enrolled and received treatment on both jaws through the straight-wire technique. Prior to treatment commencement, a semi-automatic digital setup simulating the predicted treatment outcome was performed for each patient through Orthoanalyzer software (3Shape®, Copenhagen, Denmark) to obtain the prediction model. This was compared to the final outcome model through 3D superimposition methods. Metric variables and inspection of color-coded distance maps were used to detect how accurately the digital setup predicts the actual treatment outcome. RESULTS: The mean absolute distances (MAD) between the superimposed dental arches of the predicted and the final models were: 0.77 ± 0.13 mm following superimposition on the palate, 0.52 ± 0.06 mm following superimposition on the maxillary dental arch, and 0.55 ± 0.15 mm following superimposition on the mandibular dental arch. The MAD at the palatal reference area was 0.09 ± 0.04 mm. Visualization of color-coded distance maps indicated that the digital setup accurately predicted the final teeth position in a few cases. Almost half of the cases had posteriorly wider upper and lower dental arches and palatally/lingually positioned or inclined anterior teeth, whereas the rest still showed errors within 2-3 mm, distributed over the entire dental arches with no distinct pattern. CONCLUSIONS: The accuracy of semi-automatic prediction of the labial fixed appliance treatment outcome in Class I cases with moderate crowding is not yet sufficient. While average measures showed deviations less than 1 mm, examination of individual color-coded distance maps revealed significant disparities between the simulated and the actual results.

Smile attractiveness in patients treated with or without 4 premolar extractions: A 36-year follow-up.

INTRODUCTION: This study aimed to assess the smile attractiveness in patients treated with or without 4 premolar extractions at a 36-year follow-up. METHODS: The sample comprised 52 patients with Class I and II malocclusion divided into 2 groups. Group 1 consisted of 15 patients treated without extractions (10 females and 5 males), with a mean pretreatment, posttreatment, and long-term posttreatment (T3) age of 13.2, 15.1, and 49.8 years, respectively. The mean treatment time was 1.9 years, and the mean long-term follow-up period was 34.7 years. Group 2 consisted of 37 patients (25 females and 12 males) treated with 4 premolar extractions, with a mean pretreatment, posttreatment, and long-term posttreatment age of 13.3, 15.7, and 53.6 years, respectively. The mean treatment time was 2.3 years, and the mean long-term follow-up period was 37.9 years. The mean retention time was 2 years for both groups. Frontal smiling photographs were obtained at long-term follow-up. Smile attractiveness was evaluated in an online questionnaire in which the evaluator could rate the smiling photographs with a 10-point scale. The randomly selected evaluator sample consisted of 62 laypeople, 33 dentists, and 89 orthodontists. Independent t tests, 1-way analysis of variance, and Tukey tests were used for intergroup comparisons at P <0.05. RESULTS: The smile attractiveness on the long term was similar in the groups treated with 4 premolar extractions (4.70 ± 1.35) or without extractions (4.51 ± 1.46). Women and orthodontists were more critical in assessing smile attractiveness than men, dentists, and laypeople. CONCLUSIONS: After long-term posttreatment, the smile attractiveness was similar in patients treated with 4 premolar extractions or without extractions.

Accuracy of artificial intelligence-assisted growth prediction in skeletal Class I preadolescent patients using serial lateral cephalograms for a 2-year growth interval.

OBJECTIVE: To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs). MATERIALS AND METHODS: A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm. RESULTS: All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs. CONCLUSION: Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.

Long-term profile attractiveness of patients with Class I and II malocclusion treated with and without extractions: A 35-year follow-up.

INTRODUCTION: The objective of this study was to compare the profile attractiveness in subjects treated with and without extractions after the long-term 35-year follow-up, according to laypeople, dentists, and orthodontists. METHODS: A total of 40 patients with Class I and II malocclusion were divided into 2 groups, according to the treatment protocol: extraction (E) group, extractions of 4 premolars (n = 24), with mean pretreatment (T1), posttreatment (T2), and long-term posttreatment (T3) ages of 13.13, 15.50 and 49.56 years, respectively. The mean treatment time (T2 - T1) was 2.37 years, and the long-term follow-up (T3 - T2) was 34.19. Nonextraction (NE) group (n = 16), with mean ages at T1, T2, and T3 of 13.21, 15.07, and 50.32 years, respectively. The mean (T2 - T1) was 1.86 years, and the (T3 - T2) was 35.25 years. Lateral cephalograms were used to perform profile facial silhouettes, and an online evaluation was performed by 72 laypeople, 63 dentists, and 65 orthodontists, rating the attractiveness from 1 (least attractive) to 10 (most attractive). The intragroup comparison was performed with the repeated measures analysis of variance and Tukey tests. Intergroup comparison was performed with t tests, 1-way analysis of variance, and Tukey tests. RESULTS: The E group had a longer treatment time than that of the NE group. In the pretreatment, posttreatment, and long-term posttreatment stages, the E and NE groups showed similar profile attractiveness. Laypersons and dentists were more critical than orthodontists. CONCLUSIONS: At long-term posttreatment follow-up, profile attractiveness was similar in patients treated with and without extractions.

Skeletal and dental effects of function-generating bite appliance compared to rapid palatal expander and untreated controls.

INTRODUCTION: Maxillary expansion is a fundamental interceptive orthodontic treatment, which can be achieved through either a rapid expansion protocol or functional devices. However, no data exist about the efficacy of functional devices in achieving skeletal expansion. Therefore, the aim of this study was to compare the effects of the rapid palatal expander (RPE) and the function-generating bite type M (FGB-M) on the transversal dimension of the maxilla, and on the maxillary and mandibular dental arch width. METHODS: One hundred eighty-one skeletal Class I patients, aged between 6 and 12 years and with a cervical vertebral maturation stage II or III, with maxillary transversal deficiency were retrospectively enrolled; among these 55 were treated with FGB-M, 73 were treated with RPE and 51 were untreated subjects retrieved from historical databases. The pre-treatment (T0) and post-treatment (T1) frontal cephalograms were retrieved, and the maxillary and mandibular widths, and the distance between upper and lower first molars were measured. T1-T0 interval was of 17.3 months (RPE), 24.6 months (FGB-M) and 18.2 months (controls). RESULTS: The statistical analysis showed that there were no statistically significant differences between the RPE and FGB-M groups regarding skeletal and dental expansion, while the untreated control group differed significantly from the other two groups. CONCLUSION: The comparison between patients treated with RPE and FGB-M showed that there were no statistically significant differences between the RPE and FGB-M groups regarding the amount of skeletal expansion and dental arch width, suggesting that both appliances can be used to achieve similar results.

Comparison study of chewing efficiency in patients with different vertical skeletal patterns of Angle Class I and Angle Class II malocclusions.

OBJECTIVE: The purpose of this study was to analyze and compare the differences in chewing efficiency among patients with different vertical skeletal types of Angle Class I and Angle Class II malocclusions, to provide reference for orthodontic clinical practice. METHOD AND MATERIALS: Sample size estimation revealed a minimum of 53 for each class. Thus, a total of 108 patients with Angle Class I and Angle Class II malocclusions were selected. Lateral skull radiographs were taken, and head measurements were analyzed via geometric tracing software. Chewing efficiency was measured using the gravimetric method to compare between the two groups. The vertical skeletal pattern was classified via Steiner analysis. RESULTS: Significant statistical differences in chewing efficiency were observed between patients presenting with Angle Class I and Angle Class II malocclusions (P < .05). Additionally, significant differences in chewing efficiency were observed among patients with different vertical skeletal patterns (P < .05). Furthermore, a statistically significant difference in chewing efficiency was found between men and women (P < .05). CONCLUSIONS: Patients with Angle Class I malocclusions exhibited significantly higher chewing efficiency compared to those with Angle Class II malocclusions. Among patients with different vertical facial types, the chewing efficiency followed the order of low angle > normal angle > high angle. Moreover, men demonstrated a higher chewing efficiency than women.

Three-dimensional evaluation of mandibular lingula: Comparisons of skeletal angle classifications and growth patterns.

OBJECTIVES: This study aimed to evaluate the position of the mandibular lingula (ML) in adult patients (aged between 18 and 35 years old) with different skeletal and growth patterns using cone-beam computed tomography (CBCT). DESIGN: Cross-sectional. SETTING: Dentistry department of University. SUBJECTS: Subjects comprised CBCT images of 150 adult patients, including 300 rami. METHODS AND MATERIALS: In total, 150 CBCT aged between 18 and 35 were selected and divided into three main groups of 50 samples based on their skeletal relationships (classes I, II and III). Patients were subdivided based on their growth pattern (vertical vs. horizontal), resulting in 25 samples per subgroup. Distances between the mandibular lingula and occlusal plane (ML-OP), sigmoid notch (ML-SN), external oblique ridge (ML-EOR), internal oblique ridge (ML-IOR), posterior border of the ramus (ML-PBR), inferior border of the ramus (ML-IBR), and horizontal and vertical distances to the mandibular foramen (ML-hMF and ML-vMF). One-way ANOVA variance analysis was employed to compare different angle classifications, and Bonferroni analysis was used for multiple comparisons. The Student's t-test was also used to compare growth patterns within each main group and genders within the subgroup. RESULTS: The study revealed statistically significant differences in the position of the mandibular lingula between different angle classifications, growth patterns, and genders. Class II samples showed a more anterior position of the ML, whereas Class III samples displayed a more posterior position of the ML. Patients with horizontal growth patterns and Angle Class III had a more posteriorly positioned ML. Gender differences were observed, particularly in Class I and Class III classifications, suggesting that gender may influence the variability of ML position in these specific classifications. CONCLUSION: The position of the mandibular lingula showed high variability among individuals with different angle classifications, growth patterns and genders.

Análisis bidimensional de la permeabilidad de vías aéreas con el tamaño de senos maxilares y su relación con el desarrollo de la clase esqueletal en una población mexicana / Two-dimensional analysis of airway permeability with maxillary sinus size and its relationship with the development of skeletal class in a Mexican population

Comparar la permeabilidad de las vías aéreas y el tamaño de los senos maxilares en relación con la clase esqueletal. se midieron 90 radiografías lateral de cráneo, divididas en 3 grupos, comparando las 3 clases esqueletales, las cuales se determinaron con la medida ANB de Steiner, y estas a su vez en dos subgrupos que fueron hombres y mujeres, en las cuales se utilizó el análisis de McNamara para el análisis de vías aéreas y para el área del seno maxilar se tomaron dos medidas una antero-posterior y cefálica-caudal. Al comparar los hombres con las mujeres se identificó significancia estadística en vía área superior de clase II (p=≤0.017), vía aérea inferior de clase III (p=≤0.006). Al comparar las clases esqueletales en hombres se identificó diferencias en la vía aérea superior en las clases I vs III (p=≤0.05), inferior en la clase I vs III (p=≤0,001) y II vs III (p=≤0.044). Con respecto a mujeres se identificó significancia en la vía aérea superior al comparar la clase I vs II (p=≤0,043), vía aérea inferior en la clase II vs III (p=≤0.05), longitud del seno maxilar al comparar clase I vs II (p=≤0.017). Entre la clase I esqueletal y la clase II, el tamaño de los senos maxilares resulto menor en longitud en las mujeres de clase II esqueletal. Entre la clase I y clase III esqueletal en hombres, se encontró una longitud menor en la vía aérea superior e inferior en la clase I. Las vías aéreas resultaron en menor tamaño en sujetos de clase II.

SUMMARY: To compare the airway permeability and the size of the maxillary sinuses in relation to the skeletal class. 90 lateral skull radiographs were divided into 3 groups, comparing the 3 skeletal classes, which were determined with Steiner's ANB measurement, and these were once in two subgroups that were men and women, in any McNamara analysis was used for the analysis of airways and for the maxillary sinus area measurements were made an antero-posterior and cephalic-caudal. When comparing males with females, statistical significance was identified in the upper class II route (p=≤0,017), lower class III airway (p=≤0.006). At least skeletal classes in men, differences were identified in the upper airway in classes I vs III (p=≤0.05), lower in class I vs III (p=≤0.001) and II vs III (p=≤0.044). With respect to women, significance was identified in the upper airway when comparing class I vs II (p=≤0.043), lower airway in class II vs. III (p=≤0.05), maxillary sinus length to class I vs II (p=≤0.017). Between skeletal class I and class II, maxillary sinus size was shorter in length in skeletal class II women. Between class I and skeletal class III in men, a lower length was found in the upper and lower airways in class I. The airways were found to be smaller in class II subjects.

Prevalence and extent of Alveolar dehiscence and fenestration in Class I hyperdivergent subjects with different buccolingual inclinations of maxillary molar teeth: a CBCT study

Buccolingual position of teeth could affect the prevalence of alveolar bone defects. Presence of alveolar defects may have a deleterious effect on orthodontic treatment. The aim was to assess the prevalence and extent of dehiscence and fenestration in Class I hyperdivergent subjects and correlate it with buccolingual inclinations(BL) of maxillary first molar teeth. Methods: This retrospective study involved 80 CBCTs of class I hyperdivergent subjects divided into two groups - group A (n=33) buccolingual inclination >9º and group B (n=47) buccolingual inclination <9º. Prevalence and extent of alveolar bone dehiscence and fenestrations were measured in CBCTs using OSIRIX Lite software. Descriptive statistics, Mann Whitney U test and Spearman correlation were done for evaluating intergroup differences and correlation with Buccolingual inclination. Results: Overall prevalence of dehiscence and fenestration in maxillary first molars was 60.95% and 5% respectively. In the buccal alveolar bone, prevalence of dehiscence was highest in group A (84.6%) for 16 and in the lingual alveolar bone prevalence of dehiscence was highest in group B (71.4%) for 26 . On intergroup comparison, the extent of lingual alveolar bone dehiscence (26) in group B was significantly higher (p value <0.05) than in group A. No significant correlation between the extent of dehiscence and fenestration with buccolingual inclination of molar teeth was noted. Conclusion: Molar teeth with BL inclinations of more than 9º had higher prevalence of dehiscence on the buccal side and molar teeth with BL inclinations less than 9 degrees had more dehiscence on the lingual side. But no significant correlation of BL inclination with prevalence and extent of dehiscence and fenestration was noted

Class I and Class II Patients Treated with Damon System: A Study of Transversal, Sagittal and Torque Values Variations

ABSTRACT Objective: To analyze the transversal and anterior-posterior changes obtained in patients treated only with the Damon system. Material and Methods: 51 patients with either class I or class II division 1 sagittal relationship treated with the Damon system and the same archwire sequence were retrospectively selected. Dental casts of each patient before (T0) and after treatment (T1) were scanned and analyzed using NEMOCAST 3D software. Inter-molar, inter first-premolar, inter-second premolar and inter-canine distances were measured in both upper and lower arches. Initial and final lateral cephalograms were traced using the OrisCeph program. Pre and post-treatment measurements were compared using the t-test for repeated measurements. The Pearson Correlation Index and Linear Regression Analysis were used to determine the dependence between continuous variables. The significance level was set at 0.05. Results: Transversal diameters in the upper arch increase statistically significantly, especially in the bicuspid area. Initial intra-arch diameter was the only statistically significant variable correlated with the final expansion obtained. A linear negative correlation between the initial latero-posterior torque and the final expansion was observed in both arches. Conclusion: Using identical arches in patients with very different initial characteristics, the changes in bicuspids' diameters remain the most predominant. Patients with initial more negative torque in the posterior region had a higher expansion amount.