Lower Incisors Research Articles

Identification of the Ideal Reference Site and Pain Threshold Values for the Placement of Electric Pulp Testers in Permanent Upper and Lower Anterior Teeth: A Cross-Sectional Study.

Electric pulp testers (EPTs) are widely used diagnostic tools for diagnosing traumatized teeth. Several factors can affect the result of an electric pulp test. One such factor that will affect the diagnosis is the electrode tip placement. Hence, the current study aims to identify the most painful site and response time threshold in healthy anterior teeth. A total of 90 individuals, 48 male and 42 female, aged 19 to 25 years,were recruited. An EPT was placed on three different sites: the cervical, middle, and incisal third of the labial surface of both upper and lower anterior teeth (central incisor, lateral incisor, and canine) with an appropriate electrolyte as a conducting medium. Later, the threshold values were recorded, and pain assessment was done using the Memojis pain scale (MPS). Finally, the data was analyzed statistically using the Mann-Whitney U test. Mean and standard deviation values of reaction time were collected from 540 EPT readings (three sites from 180 teeth).Among the three sites tested, the difference between the upper and lower central incisors was statistically insignificant (p > 0.05). Similarly, when upper and lower lateral incisors and canines were compared, a statistically significant difference was observed among the three sites (p<0.05). There was a significant difference (p<0.05) in the pain scores only on the incisal and cervical thirds of the upper and lower central incisors. Only the incisal third showed a statistically significant difference (p<0.05) between the pain scores in the upper and lateral incisors. At the same time, a statistically significant difference in the pain scores was observed among the three tested sites between the upper and lower canines (p<0.05). Conclusion: Lower threshold values were appreciated at the incisal third of all the upper and lower anterior teeth for placing the EPT. Most individuals have experienced a score of 2 (hurts little bit) for the perceived pain using EPTs for both the upper and lower anterior teeth.

Individualized management of chronic periodontitis in patients with orthodontic abnormalities: a clinical case report

Relevance. Chronic periodontitis is a multifactorial disease influenced by a variety of factors. Beyond periodontal pathogens and systemic conditions, important contributing factors include malocclusion, dental misalignment, and tooth loss. These conditions can compromise the tissue blood flow hemodynamics and precipitate occlusal trauma with signs of functional overload. Subsequently, this may intensify the inflammation and degradation of the alveolar bone, often leading to premature tooth loss.Correction of malocclusion is paramount in the effective management of periodontal diseases, requiring orthodontic treatment to resolve malocclusion and mitigate signs of functional overload. This treatment aims to redistribute occlusal forces uniformly, thus creating a conducive environment for successful prosthodontic rehabilitation and promoting optimal personal oral hygiene.Clinical case description. This article outlines a personalized approach to managing periodontal inflammation in individuals with orthodontic anomalies. Patient Z., born in 2002, was diagnosed with moderate severity chronic periodontitis (K05.31), presenting with a Class I molar and canine relationship on both sides, constricted dental arches, individual tooth macrodontia, and retrusion and torsiversion of the incisors. The assessment of the patient's periodontal status and overall health was conducted using standard clinical, radiographic, and laboratory diagnostics, whereas the orthodontic assessment involved anthropometric analysis of dental casts and lateral cephalometric radiographs. The periodontal intervention included foundational non-surgical treatments such as ultrasonic scaling both supra- and subgingivally, biofilm disruption using the Vector Paro system, and specific pharmacotherapy. The orthodontic treatment aimed to widen both dental arches and correct the inclination of the upper and lower incisors, achieving a normal occlusion with fixed orthodontic appliances (Damon Q brackets) in accordance with the treatment plan. The effectiveness of the treatment was measured by examining the improvement in gingival conditions, periodontal parameters, and radiographic evidence before and after the intervention.Conclusion. The research demonstrated that an individualized treatment protocol integrating periodontal and orthodontic care can substantially improve the overall health of the dentofacial complex, masticatory efficiency, and aesthetic aspects.

Effect of a novel mesh design and the sandblasting technique on the bond strength of computer-designed and three-dimension laser printed resin bonded bridges: an in vitro study

Resin-bonded bridges (RBBs) are a minimally invasive and aesthetically pleasing treatment modality. However, their frequent failure has posed challenges for both dental professionals and patients. This necessitates the exploration of innovative strategies to enhance the longevity of RBBs. This study aimed to assess the bond strength of a mesh bridge fabricated using computer-aided design and three-dimensional (3D) printing technology in comparison to the traditional aluminum oxide sandblasting method. A total of 48 lower incisors were embedded in acrylic bases according to a standardized computer-generated model to receive 24 metal RBBs. The two groups underwent distinct metal surface treatments: the 3D mesh novel design and sandblasting with aluminum oxide particles sized at 250.00 µm. The bond strength of the bridges was evaluated, and statistical analysis was performed using the independent samples t-test with a significance level set at α = 0.05. The findings revealed a significant difference between the two methods (p < 0.001). The 3D mesh design exhibited a mean bond strength of 387.89 ± 24.15 N, while the sandblasting technique yielded a mean value of 161.46 ± 31.25 N. In summary, the 3D mesh design substantially enhanced the bond strength of RBBs compared to the traditional sandblasting technique.

Severe Crowding Associated with Lower Canine Premature Resorption: Interceptive Treatment with Clear Aligners-A Pilot Study.

Early mixed dentition represents a critical phase since crowding conditions can occur. The interceptive resolution of dental crowding allows favorable arch and occlusal development. The aim of the present investigation was to evaluate dentoalveolar changes of clear aligner treatment planned to manage lower incisor crowding, loss of arch length, and midline deviation in early mixed dentition. A total of 13 patients (7 females, 6 males, 9.4 ± 1.2 age) treated with clear aligners were selected. Arch dimensions and incisor inclinations were evaluated before (T0) and at the end of interceptive treatment (T1). A paired t-test was chosen to compare T1-T0 changes. The level of significance was set at 5%. The greatest significant increase in mandibular width was observed at the level of the first deciduous molars (+2.44 ± 1.4 mm), followed by the second permanent molars (+2.16 ± 1.4 mm). Lower arch length and arch depth showed a statistically relevant increase (2 ± 0.6 mm and 4.5 ± 1.6 mm, respectively). The mean lower dental midline changes were statistically significant (1.42 ± 0.73 mm). Early treatment with clear aligners, including the combination of transversal arch development, maintenance of leeway space, and guidance of eruption, represents a valid treatment strategy in early mixed dentition to manage arch crowding and occlusion development.

Orthosurgical treatment to obtain facial aesthetics

In the present case report, a 24-year-old male underwent a combined surgical and orthodontic treatment to enhance facial aesthetics. The treatment consisted of the use of an Edgewise fixed appliance (0.022 x 0.028-in), and was complemented by a mini Wing osteotomy. The results of the treatment improved facial contours, defining and elongating the submental area, and eliminating the adipose tissue. Orthodontically, the preservation of the canines and molars Class I relationship, and the maintenance of the compensatory projection of the lower incisors were observed. Satisfactory overbite and overjet were achieved, along with a levelled curve of Spee. The combined treatment modalities led to the achievement of functional occlusion and facial aesthetics.

Prenatal and postnatal development of New Zealand white rabbit (Oryctolagus cuniculus) teeth: histological and computed tomography aspects

The study reveals a lack of histomorphogenesis in New Zealand white rabbit teeth. The teeth development was examined through sequential histological segments in 24 rabbits from prenatal ages (E19, E21, E23, E25, and E28), neonates (E30), and postnatal age (1 week and 2 weeks); (three animal specimens at each age stage). Rabbit teeth first appeared at 19 days of prenatal life (E19) as an ectodermal epithelial thickening on each side of the mouth opening. At E21, the bud of upper incisor tooth appeared as an epithelial bud, which composed of many condensed epithelium cells, was simply identified from the larger with less condensed vestibular lamina, and was surrounded by mesenchymal connective tissue while the lower incisor took the cap stage. At (E23), tooth regular construction is formed from enamel, dentine, and pulp cavity. Peg incisor appearance (supplementary and assistant incisors) is visible at the lingual surface of the upper major incisor. Teeth prenatal development went through successive stages like initiation, bud, cap, late bell, maturation, and crown stages. The first initiation phase of tooth formation was seen as ectodermal epithelial cell collection at (E19). Bud stage saw on upper incisor tooth, while in cap structure in lower incisor teeth at (E19). A cap-formed tooth is composed of the enamel organ and fundamentally dense mesenchymal tissue. Enamel organs are segmented into three distinct layers: the external tooth enamel epithelial, the internal tooth enamel epithelial, and finally the stellate reticular layer. The cement layer covered teeth all around on enamel on both the labial and lingual sides while not contacting the dentine on the lateral side, forming enamel space. Teeth develop consistently all through life; they have expanded enamel thickness; they are diphyodont teeth; they have two continuous dentitions; they are deciduous and perpetual, with long crown teeth and an open root.

Noninvasive conservative management of anterior open bite treated with TADs versus clear aligner therapy.

Anterior open bite can be treated non-surgically via molar intrusion using temporary skeletal devices (TAD). Clear aligner therapy (CAT) is recognized as a viable therapeutic modality for non-extraction treatment of adults with mild open bite. This study aimed to compare the treatment effect and mechanisms of open bite closure between patients treated with braces and TADs double arch intrusion and those treated with CAT. Treatment success at T3 was based on 1- positive overbite on ceph; 2- Change in the vertical dimension 3- post treatment POSI score equal to zero. The TAD group includes 18 consecutively treated patients from the main author. The CAT group consisted of 16 selected patients from three different orthodontists. The observation time points were as follows: pretreatment (T1), end of molar intrusion and positive overbite achieved (T2), end of treatment (T3), at least 6-month follow-up (T4). Treatment changes were assessed by cephalometric analysis and frontal intraoral photo. At the end of treatment, 100% of the patient of the TAD group and 78,6% of the CAT group had a posi score of 0. The TAD group showed a significant reduction in vertical measurements (SN-MPA: -1,55° ± 0.41, LAFH: -3,05 ± 0.51mm, U6-PP: -1.48 ± 0.30mm), but the CAT group did not have significant changes for these variables. Both groups had significant increases in overbite from T1 to T3 (TAD: 4,32 ± 0,5mm; CAT: 2,33 ± 0.56mm), and overbite remained stable at T4. The CAT group did not have a significant upper molar intrusion, but a significant extrusion of 1.22 ± 0.42mm of the lower incisor occurred. The TAD group achieved bite closure by upper molar intrusion, lower molar and incisors vertical control, and mandibular plane counterclockwise rotation, resulting in an improved AP and vertical relationship. The CAT group achieved bite closure through the lower incisor extrusion without significant change in the vertical dimension. This study provides relevant information about the skeletal and dental changes of open bite treatment with TADs double arch intrusion. The comparison with a control group treated with CAT confirms known information.

Cross Lip Vermilion Flap and Traumatic Upper Lip Avulsion: Reducing Donor Site Morbidity.

Using a cross lip vermilion flap for upper red lip reconstruction in cases other than whistle deformity in patients with cleft lip can lead to donor site morbidity. If the practitioner performs primary closure of the mucosa in lower vermilion after flap harvesting, the width and height of lower lip are reduced, which results in an increased lower incisor tooth show. Using free fat grafting is an effective method for reducing donor site morbidity in the lower lip following cross lip vermilion flap harvest.

Evaluation of modified clear Twin Block aligner in treating adolescents with skeletal class II malocclusion: A two-centre cephalometric study.

The purpose of this study was to evaluate the therapeutic effect of modified clear Twin Block (CTB) aligner and traditional twin block (TB) appliance from skeletal, dentoalveolar and soft tissue changes in adolescents with skeletal class II malocclusion. A total of 80 adolescents, included in this study from two medical centres, were distributed into CTB group, TB group and control group based on the treatment they received. Lateral cephalograms at pre-treatment (T1) and post-treatment (T2) were measured by modified Pancherz's cephalometric analysis, and dentoskeletal and soft tissue changes were analysed by independent-sample t-test, paired-sample t-test, ANOVA test and Scheffe's Post Hoc test. Seventy-five adolescents completed the study, including 32 in the CTB group, 32 in the TB group and 11 in the control group. Both CTB and TB treatment showed significant differences in most dentoskeletal and soft tissue measurements. Compared with the control group, improvements were observed in class II molar relationship through significant different in S Vert/Ms-S Vert/Mi in the CTB group (P < .01) and the TB group (P < .001), as well as deep overjet through significant different in S Vert/Is-S Vert/Ii in the CTB group (P < .001) and the TB group (P < .001). Besides, the CTB group also showed less protrusion of lower incisors and resulted in a more significant improvement in profile with fewer adverse effects on speaking, eating and social activities. For adolescents with skeletal class II malocclusion, CTB appliance was as effective as TB on improving dentoskeletal and soft tissue measurements, featuring more reliable teeth control and patient acceptance.

Tanaka-Johnston’s Mixed Dentition Analysis among Orthodontic Patients in Tanzania

Background: Lower incisors are the first teeth to erupt, their sizes are reliable and little changes occur on the lower arch during mixed dentition. These teeth can be used to predict the size of remaining unerupted teeth. Tanaka Johnston's analysis is the most widely used method of mixed dentition analysis worldwide. The aim of the study was to assess the accuracy of Tanaka-Johnston’s methods of mixed dentition analysis among orthodontic patients in Tanzania. Methods: A cross-sectional study design was carried out at MUHAS dental clinic involving models from orthodontic patients. Data collection involved actual teeth size measurement and prediction using Tanaka-Johnston’s method. Comparison between the actual measurements and the predicted measurements was assessed using students' paired t-tests. Prediction equations for the present study were generated using a simple linear regression analysis. Results: Tanaka Johnston's method significantly overestimated the combined width of upper canines and premolars in the female group (p=0.000). However, the method underestimated the lower jaw measurements in both sexes (p&lt;0.05). New prediction equations for the present study were generated for each sex and arch separately. For the upper jaw, it was Y=11.97+ 0.56X for males and Y = 10.97+0.49X for females. While for the lower jaw, it was Y= 10.8 +0.51X for males and Y=11.39+0.47X for females. Conclusion: Tanaka-Johnston’s methods of mixed dentition analysis was found to be inaccurate in estimating the size of unerupted canines and premolars in the study sample. Therefore, new prediction formulas were generated.

Influence of implant distribution on the biomechanical behaviors of mandibular implant-retained overdentures: a three-dimensional finite element analysis

ObjectiveTo assess stress distribution in peri-implant bone and attachments of mandibular overdentures retained by small diameter implants, and to explore the impact of implant distribution on denture stability.MethodsThrough three-dimensional Finite Element Analysis (3D FEA), four models were established: three models of a two mandibular implants retained overdenture (IOD) and one model of a conventional complete denture (CD). The three IOD models consisted of one with two implants in the bilateral canine area, another with implants in the bilateral lateral incisor area, and the third with one implant in the canine area, and another in the lateral incisor area. Three types of loads were applied on the overdenture for each model: a 100 N vertical load and a inclined load on the left first molar, and a100N vertical load on the lower incisors. The stress distribution in the peri-implant bone, attachments, and the biomechanical behaviors of the overdentures were analyzed.ResultsDespite different distribution of implants, the maximum stress values in peri-implant bone remained within the physiological threshold for all models across three loading conditions. The dispersed implant distribution design (implant in the canine area) exhibited the highest maximum stress in peri-implant bone (822.8 µe) and the attachments (275 MPa) among the three IOD models. The CD model demonstrated highest peak pressure on mucosa under three loading conditions (0.8188 Mpa). The contact area between the denture and mucosa of the CD model was smaller than that in the IOD models under molar loading, yet it was larger in the CD model compared to the IOD model under anterior loading. However, the contact area between the denture and mucosa under anterior loading in all models was significantly smaller than those under molar loading. The IOD in all three models exhibited significantly less rotational movement than the complete denture. Different implant positions had minimal impact on the rotational movement of the IOD.ConclusionIOD with implants in canine area exhibited the highest maximum stress in the peri-implant bone and attachments, and demonstrated increased rotational movement. The maximum principal stress was concentrated around the neck of the small diameter one-piece implant, rather than in the abutment. An overdenture retained by two implants showed better stability than a complete denture.

Hybrid Orthodontics for Aesthetic Deep Bite Correction—Case Series and General Clinical Considerations

Background: A range of psychosocial and aesthetic factors motivate patients to undergo orthodontic treatment. The appliance choice depends not only on the type of malocclusion, but also on the aesthetic and functional demands of the patients themselves. Nowadays, digital planning enables the manufacture of individualised and customised orthodontic appliances. However, the predictability of movements with aligner treatment has long been under discussion. This article illustrates, through a series of case reports, how a hybrid approach combining individualised aesthetic orthodontic appliances can improve the predictability of tooth movements, thereby providing additional tools for clinicians charged with choosing the best indicated and biomechanically advantageous technique. To this end, three patients with different malocclusions were treated via a hybrid approach involving clear aligners in the upper arch followed by lingual fixed appliances in the upper and lower arches. All patients were treated using ALIAS lingual PSL 0.018 × 0.018-inch slot brackets and in-house 3D-printed aligners. Findings: The hybrid approach combining aligners and fixed lingual appliances led to the successful resolution of all three complex cases in the series without prolonging treatment time. The superimpositions demonstrate the predictability of even traditionally difficult movements. In particular, the Alias PSL lingual system, used from the beginning, enabled good control of both the torque and inclination of the lower incisors. Conclusions: Combining clear aligners and fixed lingual appliances provides a highly efficient means of treating malocclusions aesthetically. In our cases, the aligners offset the lack of bite-plate effect from the lingual brackets and appliances, providing advantageous biomechanics for rotation correction and control of tip, torque and root movements. Understanding how to exploit the strengths of each appliance enables the clinician to treat adult patients efficaciously, efficiently and aesthetically.

Evaluation of the skeletal and dental effects of a hybrid aesthetic functional appliance (HAF) in skeletal class II division 1 malocclusion: A prospective uncontrolled clinical trial.

The present study investigated the skeletal and dental effect in class II division I growing patients due to mandibular deficiency treated with the hybrid aesthetic functional (HAF) appliance. A sample of 16 growing patients (5 boys and 11 girls; mean age: 9.50 years, standard deviation: 1.15) with class II division I malocclusion were treated using the HAF appliance for an average period of 10±3 months. For each patient, a cephalometric radiograph was taken before and after treatment, and digital analysis was applied using the WebCeph program. The statistical analysis was performed to evaluate dental and skeletal changes associated with the HAF appliance and determine if there were any statistically significant variations in anatomical measurements between the start and completion of the treatment. The data showed a significant increase in SNB angle (P=0.002), leading to a significant decrease in ANB angle (P=0.001). The mandibular length significantly increased (P=0.008), the lower incisors were flared significantly (P=0.028), and the lower molars were extruded significantly (P≤0.001). Also, this study revealed a significant decrease in Wits appraisal (P≤0.001), overjet (P≤0.001), and overbite (P=0.041). Additionally, a significant increase in lower anterior facial height (P≤0.001), total facial height (P=0.001), and posterior facial height (P=0.037) were observed. The HAF appliance showed that it could be used to correct class II division 1 skeletal discrepancy by mandibular advancement. The HAF appliance increased all facial heights significantly.

Evaluation of Root Resorption and Tooth Inclination in Class II Malocclusion Patients Treated with Advansync2 Appliance – A CBCT Study

The Advansync2 appliance is known as a tooth-borne fixed functional appliance consisting of bands cemented on permanent first molars in the upper and lower arches, to dissipate orthodontic forces. These fixed functional appliances could cause excessive proclination of the lower incisors, which could lead to inflammatory root resorption. Therefore, the purpose of this study was to evaluate the degree of root resorption and incisor tooth inclination changes in subjects with class II malocclusion who were treated with the Advansync2 appliance. 10 patients (6 males and 4 females ) between the age group of 13-20 years with class II malocclusion treated with Advansyc2 appliance were included. A CBCT of each of these patients was taken before and after the treatment with the Advansync2 appliance and evaluated for the amount of root resorption and tooth inclination in the mandibular incisor tooth region. The measurement of root resorption was made using the axial navigation method. Statistical analysis was done using SPSS software (version 22.0). A paired t-test was used to detect changes in the root length before and after the use of the Advansync2 appliance. Wilcoxon signed-rank test was used to compare the parameters of the angle of inclination as the data was not normally distributed. There was a statistically significant reduction of the mandibular anterior tooth roots by 0.52mm (p =0.01). The angle of inclination for the mandibular incisor region was reduced by 5.73 ° indicative of proclined incisors (p = 0.005).

Prediction of jaw opening function after mandibular reconstruction using subject-specific musculoskeletal modelling.

Mandibular reconstruction patients often suffer abnormalities in the mandibular kinematics. In silico simulations, such as musculoskeletal modelling, can be used to predict post-operative mandibular kinematics. It is important to validate the mandibular musculoskeletal model and analyse the factors influencing its accuracy. To investigate the jaw opening-closing movements after mandibular reconstruction, as predicted by the subject-specific musculoskeletal model, and the factors influencing its accuracy. Ten mandibular reconstruction patients were enrolled in this study. Cone-beam computed tomography images, mandibular movements, and surface electromyogram signals were recorded preoperatively. A subject-specific mandibular musculoskeletal model was established to predict surgical outcomes using patient-averaged muscle parameter changes as model inputs. Jaw bone geometry was replaced by surgical planning results, and the muscle insertion sites were registered based on the non-rigid iterative closest point method. The predicted jaw kinematic data were validated based on 6-month post-operative measurements. Correlations between the prediction accuracy and patient characteristics (age, pathology and surgical scope) were further analysed. The root mean square error (RMSE) for lower incisor displacement was 31.4%, and the error for peak magnitude of jaw opening was 4.9 mm. Age, post-operative infection and radiotherapy influenced the prediction accuracy. The amount of masseter detachment showed little correlation with jaw opening. The mandibular musculoskeletal model successfully predicted short-range jaw opening functions after mandibular reconstruction. It provides a novel surgical planning method to predict the risk of developing trismus.

Changes in the alveolar bone morphology among different patterns of incisor inclination during the alignment phase in orthodontic treatment without premolar extraction.

The present study investigated bone remodelling in the upper and lower incisor regions depending on the inclination pattern during the alignment phase of orthodontic treatment (OT). This prospective clinical study included 71 patients undergoing OT without premolar extraction. Cone beam computed tomography scans were taken before and after the alignment phase and the changes in the inclination, alveolar bone height (ABH) and bone thickness (BT) at levels 2, 3, 4, 6, 8 and 9 mm starting from the cementoenamel junction (CEJ) were determined. Teeth were divided into 'Retroinclination' (lingual crown inclination <0°), 'Proclination-low' (buccal crown inclination between 0° and 5°), or 'Proclination-high' (buccal crown inclination >5°). The alignment phase of OT resulted in ABH loss. The highest ABH loss in the maxilla was observed on the buccal side in the 'Proclination-high' and was 0.71 mm. ABH loss by 1.1 mm was observed in the mandible on the lingual side in the 'Retroinclination' group. The most significant changes in BT by up to 2 mm were observed at levels 6, 8 and 9 mm and these changes exhibited a moderate to strong correlation with the alterations in the inclination of individual incisors. At levels 2, 3 and 4 mm, the highest decrease in BT by up to 0.83 mm was observed on the palatal side of upper incisors in the 'Proclination-high' group. The direction and amount of tooth inclination partially determine changes in the bone parameters during the alignment phase.

THE RELATIONSHIP BETWEEN SKELETAL AND DENTO-ALVEOLAR INDICATORS IN CLASS II MALOCCLUSION

In instances of a distal bite, significant variability exists in the angles of inclination of frontal teeth, potentially impacting the condition of the alveolar bone, soft tissue profile of the face, and the aesthetics of the smile. The aim of this study is to establish correlations between sagittal, vertical, and dento-alveolar cephalometric indicators, and to assess which skeletal cephalometric variables in Class II skeletal patterns influence the variability of changes in the dento-alveolar complex.&#x0D; Materials and methods. A total of 47 cephalograms from patients with II class according to Engle were analyzed. Eighteen cephalometric measurements were performed using the following methods: SNA, SNB, ANB, SN_Ba, SN_Pg, NL_NSL, ML_NSL, NL_ML, Facial axis, PFH_AFH, the sum of Bjork angles, Gonian angle, I1_NL, I1_NA, i1_ML, i1_NB, i1_APg, I1_i1 license program "Audax Ceph" v. 6.6. A total of 846 measurements were made.&#x0D; Results. Class II bite pathology is characterized by prognathism of the upper jaw (increase in the SNA angle) and distal displacement of the lower jaw (decrease in the SNB, SN_Pg angles). Vertical parameters indicate a predominantly neutral type of growth. The average indicators of the inclination of the upper incisors indicate their slight retrusion. Lower incisors are characterized by a vestibular inclination. The most significant correlations of the angle i1_ML with indicators PFH_AFH (Ро=.513**, р=0), ML_NSL (Ро=-.512**, р=0), NL_ML (Ро=-.434**, р=0.002), Bjork (Ро=-.512**, р=0). Significant correlations between the incisal angles of the upper and lower jaws indicate their significant variability. Conclusions. The growth of the facial skeleton in the vertical and sagittal planes is related to the position of the incisors of the upper and lower jaws, which determines the impact on the morphology of bone tissue and facial aesthetics. Considering the interrelationships between parameters is an essential component for achieving successful functional and aesthetic outcomes in orthodontic treatment.

Association of Mandibular Incisor Proclination and Mandibular Arch Widths with The Levelling of Curve of Spee

Background: In this study, we aimed to determine the changes in mandibular incisor proclination and mandibular arch widths after leveling the curve of Spee (COS). Methods: Patients included in this quasi-experimental study were scheduled for fixed orthodontic treatment with a non-extraction therapy in the mandibular arch, no posterior crowding, eruption of all mandibular teeth except third molars, no spacing and Little’s irregularity index greater than 2. The COS depth and mandibular arch widths (inter-canine and inter-molar widths) were measured on plaster casts and recorded in millimeters. Mandibular incisors inclinations were measured on a cephalometric radiograph according to the incisor mandibular plane angel (IMPA) and lower incisor to NB (L1) angle. The pre-treatment and post-treatment values were compared using paired sample T-test. Pearson correlation was used to analyze the association between COS changes and other variables. P-value &lt;0.05 was considered statistically significant. Results: A total of 58 subjects with an average age of 25.10±6.81 years participated in this study. COS depth values significantly reduced after treatment (2.34±0.78mm vs 1.75±0.56mm), (P&lt;0.001). Average IMPA and L1-NB values significantly increased following COS flattening (P&lt;0.001). Mandibular inter-canine and inter-molar widths also showed significant increase after treatment (P&lt;0.001). Pearson’s correlation revealed a significant and inverse correlation between COS changes and mandibular arch width and mandibular incisor proclination values (P&lt;0.001 for both). Patient’s age and gender did not have a significant effect on COS depth. Conclusion: Flattening of COS leads to an increase in lower incisor proclination and mandibular arch width.

Method to measure faciolingual teeth inclination

This research evaluates the faciolingual inclination of people in Mosul city as a basebracket design for straight wire arch technique (SWA) 50 study models (25females) used aged 12-15 years, they concomitant with six keys of normal 52.that suggested by AndrewsThe data then subjected to statistical evaluation at p&lt;0.05, description of the data(mean SD.. minimum, maximum) also the correlation of all the teeth and comparison for both sexes.)The result show a higher record in lower central and lateral incisors in males (17.0whereas a lowest record found in lower iirst molar in males (-30.0). A high correlation can be seen among anterior teeth and among posterior teeth with each other

Effect of sodium hypochlorite and calcium hypochlorite on the apical sealing ability of endodontic sealers

Aim: This study aimed to compare the influence of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2 ] on the apical sealing capacity of AH Plus (Dentsply Maillefer) and Bio-C Sealer (Angelus) endodontic sealers. Methods: Sixty permanent human lower incisors were randomly allocated (http://www.randomized.org), according to the irrigant used, into three groups (n=20): 0.9% sodium chloride (NaCl/Control); 2.5% NaOCl; and 2.5% Ca(OCl)2 . The root canal was prepared with rotary files under 10 mL of the solution corresponding to the experimental group. Each group was subdivided into two (n=10) according to the sealer used for filling: AH Plus (Dentsply Maillefer) or Bio-C Sealer (Angelus). Then, all samples were immersed in black India ink for one week. After the storage period, the roots were then grooved longitudinally and split, and the ink penetration was measured from the apical part to the coronal part of the root canal into which the ink penetrated using a stereomicroscope. Data were analyzed by one-way ANOVA and Tukey’s post-hoc tests. Results: There was no statistical difference in ink penetration between the different endodontic sealers tested for the same irrigating solution (p &gt; 0.05). However, when the Bio-C Sealer (Angelus) was used, the group treated with 2.5% Ca(OCl)2 was associated with lower values of apical leakage, compared to 2.5% NaOCl (p &lt; 0.05). For the AH Plus sealer (Dentsply Maillefer), there was no difference between the irrigants (p &gt; 0.05). Conclusions: Associating Ca(OCl)2 irrigant with Bio-C Sealer (Angelus) seems to be a good option to reduce apical leakage.