Incisor Inclination Research Articles

Comparative evaluation of the position of incisive canal and its proximity to the maxillary central incisor roots with different incisor inclinations – A CBCT study

Objectives: The aim of this study was to evaluate and compare the incisive canal position and its proximity to maxillary central incisor roots at different incisor inclinations. Material and Methods: A 105 CBCT samples have been then divided into three groups on the basis of U1-SN and U1-NA when traced on lateral cephalogram into normal, proclined, and retroclined. Several linear measurements have been made in the axial plane at three different levels, that are palatal opening, mid-root level, and apex, in relation to the incisive canal. Angular measurements were also made in the sagittal plane. Results: A significant difference was found between the proximity of the maxillary right and left central incisor to the incisive canal in the proclined and retroclined group at the mid-root level and at the apex. There has been a major variation between the angles developed by the incisive canal to the palatal plane in all three groups. A significant correlation was also found between the angle formed by the incisive canal to the palatal plane and the tooth’s long axis to the palatal plane. Conclusion: The proclined group exhibits the shortest distance between the incisive canal and the incisors, implying the need for meticulous planning in Class II Division 1 and bimaxillary protrusion cases. This planning is crucial when aiming for extensive retraction and intrusion to prevent any contact with an incisive canal, thus reducing the root resorption risk.

An Evaluation of the Estimated Aligners Needed to Correct Malocclusion Traits Using Invisalign ClinCheck™ Pro Software: A Retrospective Study.

Background: This study evaluated the number of aligners that Invisalign ClinCheck™ Pro Software estimates for correcting different malocclusion traits. Methods: This retrospective study included 157 non-extraction patients over the age of 12 years old with easy to mild malocclusions who were treated with Invisalign aligners. The Index of Complexity, Outcome, and Need (ICON) was used to evaluate the malocclusion complexity level. The number of aligners (upper, lower, and total) required to correct the malocclusion was compared based on sex, ICON level, molar and canine class, occlusal asymmetry, overbite, overjet, crowding, incisor inclination, and Bolton discrepancy. A Mann-Whitney U test (for comparisons between two groups) or a Kruskal-Wallis test (for comparisons between three or more groups) (p < 0.05) was used to evaluate differences in the number of aligners across variable categories. Results: ICON, molar class, overbite, and overjet presented significant differences (p < 0.05) in the number of aligners (upper, lower, and total) required to correct a malocclusion. Canine class and lower dental crowding showed significant differences in the lower and total number of aligners (p < 0.05). Conclusions: The number of aligners increases when the malocclusion presents any of the following elements: the absence of molar or canine class I, an altered overjet or overbite, severe lower crowding, or a higher complexity level. The clinician should consider these malocclusion traits when estimating the number of aligners needed for correction.

Quantum of incisal compensation in skeletal class III malocclusion: a cross-sectional study.

Skeletal class III malocclusion presents either with maxillary retrognathism, mandibular excess, or a combination. Dentoalveolar compensations occur with maxillary incisor proclination and mandibular incisor retroclination. The aim of this study is to quantify the amount of incisal compensation in class III skeletal malocclusion and correlate it to the severity of the skeletal base. Eleven angular and 7 linear cephalometric measurements were digitized from 57 patients. Axial inclination of the upper and lower incisors was evaluated for compensation. Pearson's correlation coefficient was used to determine the dentoalveolar parameter among those measuring upper and lower incisor position and inclination that correlated most highly with the severity of class III. Linear regression analysis was used to identify the quantum of the incisal compensation. Upper incisors were proclined and placed anteriorly. However, correlation analysis suggested a less responsive incisor with progressive change in skeletal base. Lower incisors began to compensate only as the severity of class III increased. For every degree of reduction of ANB angle from normal, the incisor mandibular plane angle (IMPA) and L1-GoMe decreased by 0.79° and the L1-GoGn decreased by 0.81°. The upper incisors contributed more to compensation compared to the lower incisors in a class III skeletal base. As class III severity increased, the upper incisor compensation decreased while that of lower incisors increased. For every degree of reduction in ANB angle, the IMPA and L1-GoMe decreased by 0.79° and the L1-GoGn decreased by 0.81°.

Evaluating Clear Aligners Versus Fixed Appliances for Periodontal Patients: A Comprehensive Narrative Review of Current Evidence

Periodontal patients may face orthodontic problems because of bone support loss, such as maxillary incisor proclination, spacing, rotation, extrusion, pathologic tooth migration (PTM) or traumatic occlusion. Orthodontic treatment is therefore an element within the comprehensive treatment of periodontitis after the periodontal condition has stabilized. The presence of fixed appliances (FAs) promotes the accumulation of bacterial biofilm and impedes hygiene procedures. The increasing popularity of clear aligner (CA) treatment is due to the convenience of use, less discomfort, better esthetics, easier hygiene, lower failure rate, and shorter, less frequent visits. Therefore, the question arises whether treatment with aligners is a good solution for periodontal patients. To answer this question, the PubMed/Medline, Cochrane Library and EMBASE databases were searched using the following keywords: periodontitis, orthodontic treatment, clear aligners, multibracket orthodontic appliances, fixed appliance, root resorption, gingival recession and pathologic tooth migration. The search strategy identified 18 relevant studies. A total of 1090 participants took part in the analyzed studies. The available literature was analyzed in terms of the occurrence of root apex resorption, the possibility of treating pathologic tooth migration, the occurrence of gingival recession, periodontal health status and occlusal stability in patients treated with CAs and FAs. Despite statistically significant differences in terms of Plaque Index (PI), probing depth (PD), apical root resorption and gingival recession favor the use of CAs. However, these values are mostly of no clinical significance. It is possible to treat PTM with CAs, but it is limited by the high degree of tooth mobility and incisor inclination. Obtaining perfect occlusion is comparably difficult in both CA and FA treatment. When planning orthodontic treatment in patients with reduced periodontium, the use of both CAs and FAs should be considered. The choice of method would ultimately depend on the patient’s dental condition.

Effect of time between archwire changes on intended dentoalveolar expansion in orthodontic patients treated with fixed appliances : Aprospective controlled clinical trial.

To analyze the effects of the time span between archwire changes on the amount of transverse dental arch expansion. The design was aprospective, controlled clinical trial. Randomization was performed by computer-generated allocation tables. In all, 35patients were evaluated in three groups treated with fixed appliances and the same four sequential leveling archwires, however, with different replacement periods: 28days (4-week [4W] group), 56days (8-week [8W] group), and 84days (12-week [12W] group). Digital models were measured before the treatment (T0) and at the end of the evaluation period (T1) by ablinded operator with OrthoAnalyzer® software (3-Shape, Copenhagen, Denmark) and compared using MANOVA. Amultiple linear regression was also used to evaluate the influences of age, initial dental crowding, incisor inclination, and facial pattern on the amount of expansion. Mean expansion was 2.77 ± 0.84 mm (upper arch) and 3.12 ± 0.88 mm (lower arch) in the 12Wgroup; 1.96 ± 0.82 mm and 2.27 ± 0.96 mm in the 8Wgroup, and 1.11 ± 0.93 mm and 1.32 ± 0.91 mm in the 4Wgroup, respectively for the upper and lower arches. The amount of expansion varied significantly between the groups in the area of the canines, first premolars, and second premolars for both arches. Expansion was less in older patients. Initial dental crowding, incisor inclination and facial pattern had no influence on dental expansion. Longer time spans between archwire changes provided greater amounts of expansion, while age is inversely related, with younger patients expressing greater amounts of expansion. The results also suggest that the expansion provided by the fixed appliances is expressed mainly in the canine and premolar areas.

Diagnostic considerations and orthodontic treatment approaches of adolescents with the dentoalveolar form of class II malocclusion

Relevance. Class II malocclusion (distal occlusion) is a common pathology of the maxillofacial region in the sagittal plane and is one of the most prevalent malocclusions. Studies confirm that Class II malocclusion in adolescents exhibits significant variability, prompting the development of various treatment approaches using both removable and fixed orthodontic appliances. The challenges of adolescence include concurrent physiological and psychological changes, which can complicate the treatment process.Purpose. To enhance the effectiveness of orthodontic treatment for patients with the dentoalveolar form of Class II malocclusion by utilizing the Rotation-Torque Index (RTI).Material and methods. A study was conducted on 49 residents of St. Petersburg with physiological occlusion types, who were included in the control group. The main group comprised 95 adolescents (aged 12-18) with the dentoalveolar form of Class II malocclusion classified into three levels of severity, based on the proposed working prognostic classification.Results. A new method was developed to calculate a coefficient that describes the relationship between the position of the upper and lower jaws and the torque of the central incisors. This coefficient helps predict treatment outcomes and guides the selection of the optimal treatment strategy. The Rotation-Torque Index (RTI) was introduced to quantify the relationship between the position of the jaws in the skull (SNA, SNB) and the inclination of the central incisors of the upper jaw relative to the nasal line (NL) and those of the lower jaw relative to the mandibular line (ML).Conclusions. Based on the Rotation-Torque Index (RTI), a working prognostic classification and treatment strategies for patients with the dentoalveolar form of Class II malocclusion were proposed.

Dentofacial and skeletal effects of two orthodontic maxillary protraction protocols: bone anchors versus facemask

BackgroundMaxillary retrognathia and/or mandibular prognathia are resulting in class III malocclusion. Regarding orthodontic class III malocclusion treatment, the literature reports several treatment approaches. This comparative clinical study investigated two maxillary protraction protocols including bone anchors and Delaire type facemask.MethodsCephalometric radiographs of n = 31 patients were used for data acquisition. The patients were divided into two groups according to their treatment protocol: bone anchored protraction (n = 12, 8 female, 4 male; mean age 11.00 ± 1.76 years; average application: 13.50 ± 5.87 months) and facemask protraction (n = 19, 11 female, 8 male; mean age 6.74 ± 1.15 years; average application: 9.95 ± 4.17 months). The evaluation included established procedures for measurements of the maxilla, mandibula, incisor inclination and soft tissue. Statistics included Shapiro-Wilk- and T-Tests for the radiographs. The level of significance was set at p < 0.05.ResultsThe cephalometric analysis showed differences among the two groups. SNA angle showed significant improvements during protraction with bone anchors (2.30 ± 1.18°) with increase in the Wits appraisal of 2.01 ± 2.65 mm. SNA angle improved also during protraction with facemask (1.22 ± 2.28°) with increase in the Wits appraisal of 1.85 ± 4.09 mm. Proclination of maxillary incisors was larger in patients with facemask (3.35 ± 6.18°) and ML-SN angle increased more (1.05 ± 1.51°) than in patients with bone anchors. Loosening rate of bone anchors was 14.58%.ConclusionsBoth treatment protocols led to correction of a class III malocclusion. However, this study was obtained immediately after protraction treatment and longitudinal observations after growth spurt will be needed to verify the treatment effects over a longer period. The use of skeletal anchorage for maxillary protraction reduces unwanted side effects and increases skeletal effects needed for class III correction.

Evaluation of four machine learning methods in predicting orthodontic extraction decision from clinical examination data and analysis of feature contribution.

The study aims to predict tooth extraction decision based on four machine learning methods and analyze the feature contribution, so as to shed light on the important basis for experts of tooth extraction planning, providing reference for orthodontic treatment planning. This study collected clinical information of 192 patients with malocclusion diagnosis and treatment plans. This study used four machine learning strategies, including decision tree, random forest, support vector machine (SVM) and multilayer perceptron (MLP) to predict orthodontic extraction decisions on clinical examination data acquired during initial consultant containing Angle classification, skeletal classification, maxillary and mandibular crowding, overjet, overbite, upper and lower incisor inclination, vertical growth pattern, lateral facial profile. Among them, 30% of the samples were randomly selected as testing sets. We used five-fold cross-validation to evaluate the generalization performance of the model and avoid over-fitting. The accuracy of the four models was calculated for the training set and cross-validation set. The confusion matrix was plotted for the testing set, and 6 indicators were calculated to evaluate the performance of the model. For the decision tree and random forest models, we observed the feature contribution. The accuracy of the four models in the training set ranges from 82% to 90%, and in the cross-validation set, the decision tree and random forest had higher accuracy. In the confusion matrix analysis, decision tree tops the four models with highest accuracy, specificity, precision and F1-score and the other three models tended to classify too many samples as extraction cases. In the feature contribution analysis, crowding, lateral facial profile, and lower incisor inclination ranked at the top in the decision tree model. Among the machine learning models that only use clinical data for tooth extraction prediction, decision tree has the best overall performance. For tooth extraction decisions, specifically, crowding, lateral facial profile, and lower incisor inclination have the greatest contribution.

Correlation of Tongue Dimensions and Posture with Lower Central Incisor Inclination and Alveolar Bone Thickness in Skeletal Class I and II Malocclusion: A CBCT Study

Background: In this study, Cone-Beam Computed Tomography (CBCT) was used to assess the dimension and posture of the tongue, as well as Alveolar Bone Thickness (ABT) and labiolingual inclination of mandibular central incisors in order to look for any correlations. Methods: A total of 200 CBCT images of skeletal Class I and II individuals were studied. Each group of malocclusion was divided into three subgroups: low-angle, normal-angle, and high-angle. Buccal and lingual alveolar bone thickness (BT &amp; LT), and the Inclination of Mandibular Plane Angle (IMPA) were measured and compared by using T-test. The spearman rank correlations test analyzed the correlations between dental variables and tongue measurements (p&lt;0.05). Results: Significant weak correlations were identified between dental variables and tongue measurements. In Cl I malocclusion, IMPA and Tongue Length (TGL) were found to be significantly correlated with a correlation value of 0.324 (p=0.001). In Cl II malocclusion, there was a significant correlation between BT3 and TGH. About BT3, there was a significant correlation with D4’ and a negative correlation with D5’. Further comparison among vertical subgroups revealed the same results. Conclusion: Class I patients with superior tongue posture may have thicker lingual alveolar bone around mandibular incisors and Class II patients showed that thicker labial alveolar bone of lower incisor and thinner alveolar bone at the lingual side may be associated with a superior position of the posterior portion of the tongue.

Favourable dentoalveolar changes after lower premolar extractions for Class III camouflage with completely customized lingual appliances

BackgroundThe aim of the investigation was to evaluate if the inclination of the lower anterior teeth can be controlled reliably after lower premolar extraction for Class III camouflage treatment with completely customized lingual appliances (CCLAs). Treatment outcome was tested against the null hypothesis that lower premolar extractions for non-surgical camouflage treatment of a Class III malocclusion will lead to further compensation by retroclining mandibular incisors during CCLA treatment.MethodsThis retrospective study included 25 patients (f/m 12/13; mean age 20.7 years, SD 9.5 years) with uni- or bilateral Class III molar relationship and a Wits value of ≤ -2 mm. In all consecutively debonded patients, lower premolars were extracted to correct the sagittal relationship with a non-surgical camouflage approach. Lateral head films prior to (T1) and at the end of lingual orthodontic treatment (T2) were used to evaluate skeletal and dentoalveolar effects. A paired t-test with alpha = 5% was used to define differences between the endpoints. The linear correlation between the inclination of the mandibular incisors at T1 and the achieved correction was measured with the Pearson correlation coefficient (PCC). A Schuirmann’s TOST equivalence test was used to check if the final lower incisor inclination was within the defined norms.ResultsThe null hypothesis was rejected as the mean lower incisor inclination was improved by 1.8° despite lower premolar extractions (T1: 86.8°/ T2: 88.6°). There was a strong correlation (-0.75) between the lower incisor inclination at T1 and the achieved correction indicating a controlled correction towards the norm regardless of the initial incisor position. At T2, the interincisal angle as well as the lower incisor inclination were within the norm.ConclusionLower premolar extractions for non-surgical camouflage treatment of a Class III malocclusion will not lead to undesired retroclining of mandibular incisors during CCLA treatment even in severe cases.

Craniofacial features and incisor position design of esthetics population after orthodontic treatment.

This study aims to provide craniofacial features and incisor position prediction models among esthetics population after orthodontic treatment. A total of 338 patients with esthetic profiles were selected from 1 055 post-orthodontic adults based on inclusion and exclusion criteria and scored by five dental students. Mean values of cephalometric measurement were demonstrated with gender and sagittal skeletal pattern (ANB) differences assessed by generalized estimating equation. Correlations among age, skeletal, and soft tissue variables in different genders were determined. Multivariate analysis was used to assess the influence of skeletal and soft tissue variables on orthodontic incisor position. Within the esthetic cohort after orthodontic treatment, gender differences existed in cranial and mandibular length, mandibular rotation, protrusion of pogonion, inclination of maxillary incisors, upper lip thickness, lower 1/3 face height, and nose protrusion. However, in class Ⅰ malocclusion, the development of the chin showed no significance, whereas the protrusion of the lower lip significantly differed between genders, with less protrusion in males. In males, the protrusion of lip and chin varied among groups, with thinner basic upper lip thickness of class Ⅱ than class Ⅰ and greater lower lip height of class Ⅲ than class Ⅰ. In females, the protrusion and height of the upper lip and chin varied in groups, with thicker basic upper lip thickness of class Ⅲ than class Ⅰ. Upper lip thickness, female basic upper lip thickness, and female lower lip height were correlated with age. The protrusion of the upper lip was mainly correlated with posterior cranial base, mandibular body length, ANB in male and SNA, ANB, sagittal maxillary length, mandibular rotation, and protrusion of pogonion in female. The protrusion of the lower lip in males was mainly correlated with ramus height, mandibular rotation, protrusion of pogonion in male and ANB, mandibular rotation, and protrusion of pogonion in females. After employing skeletal variables to fit dental parameters, optimal results were achieved in male IMPA (adjusted R2=0.712) and female G Vert-U1 (adjusted R2=0.795). After employing skeletal and soft tissue variables simultaneously, optimal results were achieved in male and female G Vert-U1, which was mainly influenced by the protrusion of the chin and nasal base in males (adjusted R2=0.836) and the protrusion of the nasal base as well as ANB in females (adjusted R2=0.842). This study demonstrated the craniofacial features of esthetics population after orthodontic treatment and revealed the correlation of gender, age, skeleton, and soft tissues to provide reliable prediction models for aesthetic orthodontic incisor position.

Lip and incisor changes in patients with different ethnicities treated with extraction versus nonextraction: A cone-beam computed tomography study

This study used cone-beam computed tomography (CBCT) via voxel-based superimposition to evaluate lip and incisor changes after orthodontic treatment with four premolar extractions (Ext) versus nonextraction (Non-Ext) among African American (AA) and White (W) patients. A total of 240 CBCTs of 120 adolescent orthodontic patients with Class I skeletal/dental relationships were included. Patients were initially divided according to treatment, and then each group was subdivided according to patients' ethnicity (Ext/W = 30, Ext/AA = 30, Non-Ext/W = 30, and Non-Ext/AA = 30). CBCTs were imported into Invivo6 for voxel-based superimposition. Lip and incisor measurements were recorded. Independent t tests and two-way ANOVA were used for statistical assessment. The Non-Ext/W group had a greater increase in all outcome variables compared with the Non-Ext/AA group, with a significant change in volume and position of upper (UL) and lower lips (LL), inclination of upper (U1) and lower incisors (L1), and position of U1. The Ext/AA group had a greater decrease in all measured outcomes compared with the Ext/W group, with significant change in inclination of U1 and L1, and position and volume of LL. W patients had more crowding than AA patients in both treatment approaches. Retraction ratios of 6.5:1 and 2.1:1 were recorded between the U1 and UL positions, and L1 and LL positions, respectively. There were no direct interaction effects between ethnicity and treatment, nor were there any significant effects of ethnicity after controlling for the covariates. Ethnicity alone has no impact on incisor and lip position after treatment. However, ethnicity in the form of initial presentation of malocclusion can have a significant influence.

Is occlusal contact re-established within 6 months after bonding of a fixed anterior bite plane in adolescents with a Class II division 2 incisor relationship? A randomised controlled trial.

To determine if re-establishment of occlusal contact was achieved within 6 months after insertion of a fixed anterior bite plane in individuals with Class II division 2 incisor relationship, and to evaluate the occlusal and vertical skeletal changes and acceptance of the intra-oral scanner and bite plane. Single-centre two-arm parallel group randomised controlled trial with 1:1 allocation to intervention and control groups. Dundee Dental Hospital and Research School, UK. A total of 38 participants aged 9-16 years (11 males, 27 females) with Class II division 2 incisor relationship and increased overbite (greater than one-third incisor overlap). Participants were randomised to intervention (n = 19) and control (n = 19) groups using block randomisation. The intervention group had a fixed anterior bite plane, and the occlusion and vertical facial dimensions were monitored with intra-oral scans, lateral cephalograms and photographs. The control group received no treatment and occlusal and vertical facial dimensions were monitored with scans and photographs. Questionnaires were completed by participants and parents/carers. An intention-to-treat analysis was planned. The overbite reduced in all participants in the intervention group (mean initial overbite: 5.07 mm, 95% confidence interval [CI] = 4.15-6.00; mean overbite after 6 months: 2.45 mm, 95% CI = 1.93-2.96). There was a mean incisor intrusion of 0.29 mm (95% CI = 0.17-0.42) and mean eruption of the first molars of 0.23 mm (95% CI = 0.09-0.37). There was no significant change in incisor inclination or vertical skeletal change. Feedback from participants and their parents/carers were generally positive. Fixed anterior bite planes effectively reduce an increased overbite in adolescents with a Class II division 2 incisor relationship, due to a combination of incisor intrusion and molar eruption with no change in incisor inclination or vertical skeletal change. Intra-oral scanning and fixed anterior bite planes are acceptable in adolescents.

Effect of interproximal enamel reduction on interradicular bone volume in clear aligner therapy: a three-dimensional cone-beam computed tomography study.

To assess the effect of inter-proximal enamel reduction (IPR) on interradicular bone volume and incisal inclination in patients undergoing clear aligner therapy (CAT). The study sample consisted of 60 cases which underwent orthodontic CAT, in a private clinic in Dammam, KSA. A total of 120 CBCT scans (60 pre-treatment and 60 post- treatment) were measured using the CS 3D Imaging software to examine bone volume (using height, width, and depth of the interproximal area) and incisal inclination. The corresponding ClinCheck models were collected to determine the amount and locations of interproximal reduction performed. Little's Irregularity Index values were measured using OrthoCAD software. Paired sample t-test was used to address the measurements of bone height, width, depth, bone volume, and inclination of upper and lower incisors before and after IPR. IPR did not affect the upper or lower bone volume except at LR3-2 and UL 2 - 1 where a significant difference between the bone volume with and without IPR was detected (p = 0.02 and p = 0.04 respectively). Upper and lower incisor inclination showed a statistically significant decrease after IPR. There was no correlation between IPR and bone volume difference between upper and lower teeth except at LR3-2 and UL 2 - 1. IPR had no significant effect on inter-radicular bone volume except at areas of lower right canine-lateral and at areas of upper left central-lateral. There was a positive correlation between the amount of IPR and incisal inclination. The current study findings suggest that while IPR has a minimal and localized effect on bone volume in certain areas, it plays a role in adjusting incisal inclination, highlighting its significance in the careful planning of orthodontic treatment using clear aligners.

Comparison of Upper Central Incisor Torque in the ClinCheck® with and without CBCT Integration: A Cross-Sectional Study.

Controlling root movement is one of the greatest challenges in orthodontic treatment with aligners, like Invisalign® aligners. Cone Beam Computed Tomography (CBCT) integration into ClinCheck®, enabling bone and root visualisation, allows a more accurate follow-up of the teeth position. This study aims to compare torque measurements of the upper central incisors with and without CBCT and relate them to the upper incisor inclination and facial biotype. In a sample of 70 teeth, torque measurements were obtained by importing images into AutoCAD® software (version 2024). The angle between the tooth's long axis with CBCT duplicate and the tooth's long axis without CBCT was obtained to assess the difference. Statistically significant differences between torque measurements with and without CBCT were found, as well as between these measurements and the inclination of the upper incisors. No statistically significant differences were found among the facial biotypes. The average values of 27.8° ± 3.4° and 21.5° ± 3.2° were obtained for the angle between the axes. Torque without CBCT was lower than torque with CBCT, for the same tooth. The angle between the axes had a similar mean for both teeth. CBCT integration into ClinCheck® allows for a more correct torque measurement.

A comparative study to evaluate the influence of the incisal inclinations of maxillary central incisors in gujarati men and women on the perception of smile esthetics among orthodontists, general dentists and lay persons

The aim of this study is to investigate the influence of different incisal inclinations of the maxillary central incisors in an analysis of full face and close up views of the smile on the perception of smile esthetic in Gujarati men and women between orthodontists, general dentists and laypersons. Frontal smile and Lateral profile photographs were digitally altered at full-face view and close-up view of adult men and women aged 15-30 years were used. The patient wase made to sit with a natural head position. Six incisal labial and lingual inclinations of the central incisors were simulated with changes of 5 degree. Alterations in the labially inclined direction were labeled as positive and those in the palatally inclined direction were labeled as negative. The positions were denominated as follows: 5 ͦ, 10 ͦ, 15 ͦ, ‐5 ͦ, ‐10 ͦ and –15 ͦ, according to incisal inclination changes of the central incisors. To simulate the different incisal inclinations adobe Photoshop CS 8.0 was used. The top limit of the full-face image was a region little above the top of the head and the bottom limit was the base of the neck. The images were randomly assembled in an album that were presented to 40 orthodontists, 40 general dentists and 40 laypersons who evaluated the attractiveness of the images by using Visual Analogue Scale. 10was found to be most attractive incisal inclination.

Effects of Nail Biting (Onychophagy) on Upper Central Incisors in Children and Young Adolescents

Nail biting (NB) is a repetitive and uncontrolled parafunctional activity that can affect oral health by altering tooth shape and intraoral position. Nowadays, there is not enough scientific evidence about the impact of NB on teeth; therefore, this study aimed to evaluate the effects of NB on the length, width and inclination of upper central incisors. This retrospective study involved 76 patients, 40 males and 36 females, with a mean age of 10.6 ± 0.3 years. Digital scans of the maxillary arch of each patient were recorded. Next, the length, width and inclination of upper central incisors used and not used for NB were measured. Finally, data were analysed with a paired t-test. Statistical analysis showed statistically significant differences in the length and inclination of upper central incisors used for NB compared with those of upper central incisors not used for NB, while the width did not show a significant difference. There were relevant changes in upper central incisors subjected to NB, demonstrating that NB impairs the shape, morphology and inclination of teeth. Therefore, because of the potentially negative consequences of NB, it is recommended that NB not be underestimated.

Craniofacial Cephalometric Morphology in Polish Adolescents with Cleft Palate Only.

Background: Cephalometric studies indicate that craniofacial morphology in patients with cleft palate only (CPO) differs from other forms of orofacial clefts and healthy patients. Planning orthodontic treatment for patients with different craniofacial deformities requires knowledge on the craniofacial complex. The aim of the present study was to describe the cephalometric craniofacial morphology in adolescents with cleft palate only compared to generally healthy orthodontic patients. Methods: The study comprised 100 lateral cephalograms (taken in the years 2003-2020) of Polish patients with cleft palate only aged from 11.1 to 14.2 (mean age 12.43 y) and a matched control group of 100 children without orofacial clefts aged 12-14 (mean age 12.25). All digital images were analyzed in specialized cephalometric software. Results: Statistically significantly lower values of both SNA (p < 0.001) and ANB (p < 0.001) were found in the study group versus the control group. Mandibular line to cranial base angle (ML-NSL) as well as maxillary base to cranial base (NL-NSL) were significantly higher in the CPO group. Both the maxilla and mandible were rotated distally in CPO. Moreover, the intermaxillary vertical angle (ML-NL) was reduced in CPO. Mandibular angle in CPO was significantly higher (p = 0.005), reflecting posterior mandibular rotation. Conclusions: In adolescents with CPO, maxillary deficiency is found, without a severe sagittal jaw discrepancy, with a slight compensatory lingual inclination of the lower incisors. Mandibular deficiency in CPO is concurrent with posterior rotation and an increased mandibular angle.

Retention efficacy and patient experience with customized clear retainer and wrap-around circumferential retainer among non-extraction orthodontic patients: A 12-month follow-up cohort study.

The aim of this study was to evaluate retention efficacy by assessing retention stability and patient perspectives according to type of circumferential retainer: the wrap-around circumferential retainer (WCR) and customized clear retainer (CCR). This cohort follow-up study involved 52 patients aged 18-62 who underwent fixed-appliance orthodontic treatment without extractions or orthognathic surgery. Following screening consenting participants were divided into WCR and CCR groups. All participants before follow-up received fixed retainers for the upper and lower anteriors and respective removable retainers within 2 weeks post-debond. Intraoral scans and lateral cephalograms were taken immediately after debonding (T0) and again 12 months later. Dentoalveolar changes in several measurements were compared to evaluate retention efficacy. Surveys were conducted at 1 month (T1) and 12 months (T2) post-debonding to assess changes in patient experiences. Outcome assessments were blinded. Paired T-tests and independent T-tests were used for intragroup and intergroup comparisons of dentoalveolar measurements, respectively. Survey responses were analysed using the Pearson Chi-Square test. The final assessment included 32 participants. Model analysis revealed no significant differences between the groups, except for maxillary intermolar width (p = .033). In the WCR group, the cephalometric analysis indicated a significant increase in the incisor mandibular plane angle (p = .002) and a decrease in the interincisal angle (p = .014), while changes in the CCR group were statistically non-significant. Patient attitude evaluation showed similar trends for wear time and overall satisfaction. However, a higher percentage of respondents in the WCR group reported irritation when wearing the retainers (p = .037) at T1 and discomfort related to speech (p = .038) at T2. CCR showed better retention efficacy in terms of lower incisor inclination. Patients experienced relatively less irritation and speech discomfort with CCRs.

Impact of Invisalign® first system on molar width and incisor torque in malocclusion during the mixed dentition period.

In orthodontic treatment of patients during the mixed dentition period, arch expansion and opening deep overbite are one of the objectives to achieve proper alignment of the teeth and correction of sagittal and vertical discrepancies. However, the expected outcomes of most therapeutic regimens are not clear, making it impossible to standardize early treatment effects. Therefore, this study was designed to evaluate the impact of the Invisalign® First System on the dental arch circumference and incisor inclination in patients during the mixed dentition period. A total of 21 children during the mixed dentition period (10 females and 11 males, with an average age of 8.76 years) were included in this study. The patients received non-extraction treatment through Invisalign® First System clear aligners, and no other auxiliary devices were used except Invisalign® accessories. Subsequently, the cooperation degree of patients during treatment and the oral measurement parameters at the beginning (T1) and the end (T2) of treatment were collected. All patients showed moderate/good cooperation degree during treatment. Besides, horizontal width of the maxillary first molar increased significantly; the designed arch expansion was 4.1 mm (±1.4 mm), while the actual arch expansion was 3.0 mm (±1.7 mm). Furthermore, the torque expression rate of upper anterior teeth reached 56.53%. Invisalign® First System clear aligners can effectively correct the teeth of patients during the mixed dentition period, widen the circumference of dental arch, and control the torque of incisors.