Incisor Inclination Research Articles

Comparison of Maxillary Central Incisor, Crown Angulation and Tooth Size Variation in Aesthetic and Non-aesthetic Smiles- A Cross Sectional Study

Background: An attractive smile is often attributed to incisor alignment and proclined or retroclined incisors could contribute to a less aesthetic smile. Objectives: This study was aimed to evaluate the maxillary central incisor crown inclination, crown angulation and tooth size variation in aesthetic and unattractive smiles. Methods: The study was conducted among 100 females (equally divided into aesthetic and unaesthetic smile groups), aged between 15 - 25 years, with Angle’s Class I normal occlusion and balanced profiles. Variations in maxillary central incisor crown inclination and angulation were measured on lateral cephalograms, photographs and the study models of the subjects. Variations in tooth morphology were also evaluated by measuring crown height and width in both groups. Mann-Whitney U test was performed to evaluate the difference between the aesthetic and unaesthetic smiles. P < 0.05 was considered as significant. Results: This study showed that incisor angulation was significantly higher in the unaesthetic group compared to the aesthetic group (P < 0.001). However, there was no statistically significant difference for the incisor inclination relative to the Palatal Plane between the aesthetic and unaesthetic smile groups (P = 0.086). In addition, there were significant differences between the aesthetic and the non-aesthetic groups regarding the central incisor height (P < 0.05). Conclusions: The findings of this study indicate that the possible variations in aesthetics are related to the ethnic elements that are associated with differences in crown angulations, as well as tooth size.

Implications of pretreatment incisor inclinations for the achievement of cephalometric normal values-astudy on two patient collectives.

The objective was to clarify whether standardized multibracket therapies-differing only in finishing-wire dimensions (0.016 × 0.022 inch vs. 0.017 × 0.025 inch CNA [Connecticut New Archwire]) and excluding any extraction treatment or additional appliances other than intermaxillary elastics-can produce normal incisor inclinations starting from different baseline inclinations. We analyzed pre- and posttreatment cephalograms of 156 patients (age: 15.6 ± 1.3years) treated with Roth system (0.018 inch slot). Each archwire group (n = 89 or 67) was divided into subjects with initially retroclined, orthograde, or proclined upper and/or lower incisors (U1, L1). For the resultant 12subgroups, descriptive statistics were compiled relative to five reference planes (NL, ML, NA, NB, BOP), followed by multiple intragroup (Kolmogoroff-Smirnoff and Wilcoxon signed-rank test) and intergroup (Kruskal-Wallis and Mann-Whitney U test) comparisons relative to NL or ML. The following intra- (1, 2) and intergroup (3, 4) differences were statistically significant (p ≤ 0.05) in both archwire groups: (1)post- vs. pretreatment inclinations in the subgroups initially retroclined U1, retroclined L1 and orthograde U1, but without normal values being achieved (subgroups retroclined U1, L1) or preserved (subgroup orthograde U1); (2)observed vs. expected alterations for the subgroups initially orthograde and proclined U1 and L1; (3)posttreatment inclinations for the subgroups initially retroclined vs. orthograde L1 and proclined L1; (4)observed alterations for the subgroups initially retroclined vs. proclined U1 and L1, but neither retroclined nor proclined vs. orthograde. Archwire thickness influenced the outcome to only alimited extent under the special circumstances of this study. The bracket/archwire combinations evaluated did not lead to normal incisor inclinations in most cases. Posttreatment values did significantly depend on the pretreatment situation. Most frequently, alterations were protrusive in direction, which notably even included incisors that showed norm values at the outset of treatment. It can be concluded that bracket torque will influence but not dominate incisor inclinations.

Skeletal and dental effects of Herbst appliance anchored with temporary anchorage devices: A systematic review with meta-analysis.

The aim was to evaluate the efficiency of using temporary anchorage devices (TADs) in minimizing the anchorage loss and increasing the skeletal effects during correction of Class II malocclusion with Herbst appliance. Search without restrictions was performed up to January 2021 in three electronic databases (CENTRAL, MEDLINE and EMBASE) for randomized controlled trials (RCTs), prospective and retrospective cohort studies. The included studies assessed the dental and skeletal changes in Class II malocclusion patients who were treated using Herbst appliance with or without TADs. The strength of evidence was ranked using GRADE. Fifty-five records were initially retrieved. A total of 6 studies with 198 patients were finally considered. 4 studies were included in the meta-analysis. The meta-analysis showed that using TADs with acrylic splint Herbst appliance was effective in controlling the inclination of mandibular incisors by a mean difference of -5.49 degrees (95% C.I [-7.36, -3.63], P<.001) when compared to Herbst appliance alone. The results showed also that incorporating TADs with Herbst treatment resulted in greater mandibular skeletal effects including increasing mandibular bone base length by mean difference of 2.22mm (95% C.I [0.82. 3.61], P=.002) and mandibular length by mean difference of 3.7mm (95% C.I [1.55, 5.85], P<.001) when compared to Herbst appliance alone. Based on a very low level of confidence, it seems that incorporating TADs during orthodontic treatment with Herbst appliance results in minimizing the anchorage loss and increasing the skeletal effects of Herbst appliance during correction of Class II malocclusion.

Class II division 1 malocclusion treatment with extraction of maxillary first permanent molars: cephalometric evaluation of treatment and post-treatment changes

Abstract Objective To investigate the cephalometric outcome and post-treatment changes following the orthodontic treatment involving the extraction of maxillary first molars in patients presenting with a Class II division 1 malocclusion. Methods A retrospective longitudinal study was conducted involving 83 patients treated by fixed appliances and the extraction of 16 and 26. The mean age at commencement was 13.2 ± 1.5 years. Lateral cephalograms were available pre-treatment (T1), immediately post-treatment (T2), and at 2.6 years post-treatment (T3). The sample was divided into hypodivergent (n = 18), normodivergent (n = 17), and hyperdivergent (n = 48) facial types. Mean increments, standard deviations, and 95% confidence intervals were calculated for T2–T1 and T3–T2. Increments were tested using paired-samples t-tests, and variables between groups by applying ANOVA followed by Tukey’s post hoc test. Linear regression was used to examine the effect of facial type, age, and gender. Results Significant changes occurred during treatment for most cephalometric variables. Post-treatment, the growth pattern showed a tendency to return to the original form. Facial type had only a minor influence on cephalometric increments during and after treatment. Conclusions Post-treatment skeletal, soft tissue, and dentoalveolar changes were limited. Facial type had only a minor influence during and after treatment and care must be taken to control lower incisor inclination.

Evaluation of Upper Airway Dimension in all Four First Premolar Extraction Cases

Objective: To find out any noticeable size difference in the superior airway at the end of premolar extraction treatment and to find out the effects of extraction on axial inclinations of anterior teeth. Methodology: It was a retrospective quasi-experimental study that consisted of 30 orthodontic patients in which all four first premolars were extracted. The orthodontic treatment of the participants was done at Department of Orthodontics, Jinnah Medical and Dental College, Karachi. The data was collected from January 2020 to March 2020. Sampling technique selected was consecutive which is a non- probability type of sampling. The cases included in this study were skeletal and dental class I having class I molar relationship with crowding that required all four first premolar extractions. Patients having syndromes or in need of orthognathic surgery were excluded from this study. The analysis was done on Lateral Cephalometric radiograph which was captured in the beginning and another one once treatment was completed. On these radiographs, changes in the soft palate and upper airway widths were measured. Results: No appreciable alterations observed in the superior airway and soft palate widths. The difference observed in the upper incisors inclination was significant when compared to their pretreatment values. Conclusion: No appreciable change has been noted in the airway dimensions after extraction of premolars. The extractions done as a part of orthodontic treatment results in a great improvement in the correction of proclinations of anterior teeth and reduction of lip procumbency. Key Words: Premolar extractions, Lateral Cephalogram, Airway

Changes in the Skeletodental, Soft tissue and TMJ of Class II Division.1 Malocclusion Patient Following Orthodontic Treatment with Twin block Appliance: A Prospective Clinical Study

The purpose of this study was to evaluate the treatment outcome of Twin Block functional appliance and to determine the skeletodental, soft tissue and TMJ changes concurrent with the treatment. Ten subjects 5 males and 5 females with age ranged from 9 to 11 years were used in this study. All the cases showed Angle's Class II division 1 malocclusion due to mandibular retrusion. For each case out of the ten, lateral Cephalometric x-ray, right and left tomographic X-ray were done before and after treatment. On the base of the data obtained from this study both skeletodental and soft tissue improvement were detected after treatment. Also a significant reduction of the posterior joint space with significant increase of the condylar head thickness was seen. These outcomes make the appliance very effective in cases with retrognathic mandible, orthognathic maxilla and normal incisors inclination.

Treatment of mild Class II malocclusion in growing patients with clear aligners versus fixed multibracket therapy: A retrospective study

ObjectiveTo compare the dental and skeletal effects of intermaxillary elastics on the correction of mild Angle's Class II division 1 malocclusion with clear aligner treatment (CA) versus fixed multibracket (FMB) in growing patients.Settings and sample populationThe study sample consisted of 49 consecutively patients (mean age ± SD 12.9 ± 1.7 years), 32 females and 17 males referred from the School of Orthodontics of the University of Bratislava Comenius (Slovakia). All patients were treated with a non‐extraction orthodontic treatment, 25 with FMB and 24 with CA.MethodsThe cephalometric analysis was performed at the beginning (T0) and the end of the treatment (T1). The t test for unpaired data was carried out to compare cephalometric values at T0 and changes at T1‐T0 between the two groups. The level of significance was set as P < .0035.ResultsThe two groups showed no statistically significant differences (ANPg = −0.1°; P = .762) in the correction of the sagittal intermaxillary relation. The analysis of vertical skeletal changes showed no statistically significant effects on mandibular inclination (SN/MP = 0.1°; P = .840). The two treatments had a statistically significant and clinically relevant difference in controlling the inclination of the lower incisors (L1/GoGn = 4.8°, CAG = −0.5°± 3.9°; FMB = 4.3°± 5.8°; P < .001).ConclusionsClass II elastics combined with CA and FMB produce a similar correction on sagittal discrepancies in growing patients. CA presented a better control in the proclination of the lower incisors. CA and elastics might be a good alternative in the correction of mild Class II malocclusion in cases where a proclination of lower incisors is unwanted.

English

BACKGROUND A deep overbite may be due to an underlying skeletal or dentoalveolar component that may influence the treatment plan. The purpose of this study was to evaluate and compare the different components of deep bite malocclusion and normal occlusion. METHODS This was a case control study. Lateral cephalograms and study casts of normal (N = 50) and deep overbite (N = 50) subjects were used to evaluate skeletal and dentoalveolar components. Data was analysed statistically by independent t - test. RESULTS The significant skeletal contributing factors were gonial angles, mandibular plane, maxillary plane angle &amp; ramus / Frankfort horizontal. An increased curve of Spee and decreased mandibular first molar height were predominant dental variables in the deep overbite group. The inclination of the upper incisors &amp; lower incisors height did not show a statistically significant difference between the two groups. CONCLUSIONS The counterclockwise rotation of the mandible and the increased curve of Spee were the dominant features of deep bite malocclusion. This analysis of deep overbite components could help clinicians design individualised mechanotherapy based on the underlying cause rather than being prejudiced toward conventional mechanics when correcting with a deep overbite malocclusion. KEY WORDS Skeletal and Dental Components, Deep Overbite, Ramus / Frankfort Horizontal

Incisor and profile alterations in extraction cases treated with standard Edgewise and pre-adjusted appliances: A controlled before-and-after study

Even though treatment of Class II malocclusion with premolar extractions and incisor retraction might affect incisor inclination and soft tissue profile, the effects of bracket prescription on this have not been thoroughly assessed. Fifty patients (mean age: 13.6 years; 34% male) receiving extraction-based treatment with either standard Edgewise or pre-adjusted appliances were included. Between-group differences in the incisor inclination assessed with lateral cephalograms were analyzed statistically with linear/logistic regression at 5%. Treatment-induced changes included retroclination of the upper/lower incisors (-3.0° and -2.0°, respectively), retraction of the upper/lower incisors (-3.4 mm and -1.5 mm, respectively), retraction of the upper/lower lip (-2.1 mm and -2.0 mm, respectively), and enlargement of the nasolabial angle (+1.6°). Analysis of the data adjusting for confounders indicated that the pre-adjusted group, after treatment, had larger inclination of the upper or lower incisors (+3.2° and +4.5°, respectively), more prominent upper incisors relative to the facial plane (+1.3 mm), and smaller interincisal angle (-7.3 or -7.7°). Post-treatment upper incisor inclination fell within the cephalometric norm significantly more in the pre-adjusted than in the standard Edgewise group (odds ratio 4.3; 95% confidence interval 1.1-16.6). No differences were found in lower incisor prominence, upper/lower lip prominence, or nasolabial angle. Pre-adjusted appliances were associated with increased inclination of the upper and lower incisors, with more prominent upper incisors, and with more acute interincisal angle after retraction compared with standard Edgewise appliances. However, such differences did not translate in greater retraction of the upper/lower lips and greater nasolabial angle.

The influence of incisor inclination and anterior vertical facial height on facial attractiveness in an Asian woman

Orthodontic treatment can help improve facial attractiveness through the modification of factors affecting the soft tissue profile. The objectives of this study were to determine the impact of different maxillary incisal inclinations and lower anterior facial heights (at rest and with a smile) on the facial attractiveness of an Asian woman, as perceived by different panels of raters using visual analog scale (VAS) scores. A cross-sectional study was performed with 66 raters equally divided into 3 panels that consisted of general dentists, orthodontic residents, and laypersons. Raters assessed modified photographs of a subject with various incisor inclinations and lower anterior facial height/total anterior facial height (LAFH/TAFH) on lateral profile view. Modifications were made using Photoshop software (Adobe, San Jose, Calif). Subjective evaluations of facial attractiveness were performed by raters using VAS. Kruskal-Wallis test was used to compare VAS scores among raters. Mann-Whitney U test was applied to compare VAS scores between groups. Significant differences in VAS scores were found among raters for -10° (P=0.004) and -15° (P=0.021) incisal inclinations. Significant differences were found in VAS scores for -8% LAFH/TAFH (P=0.044) and 4% LAFH/TAFH with smile (P=0.002). Professionals preferred normal incisal inclinations to be the most attractive. General dentists found reduced facial height to be unattractive. Orthodontic residents and laypersons considered increased LAFH/TAFH to be most unattractive. Smile had a negative impact on VAS scores at extreme anterior facial height modifications.

Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea.

To characterize the mandibular anterior teeth crown height as a marker of periodontal changes and bone loss as a side effect of an oral appliance worn for a minimum of 4.5 years. This retrospective study conducted in patients with healthy baseline periodontium recruited participants among consecutive sleep apnea patients treated with an oral appliance between 2004 to 2014. Eligible participants were recalled for a follow-up visit at which a periodontal examination was performed and a lateral cephalogram and dental impressions were obtained. Clinical crown height for mandibular anterior teeth and cephalometric variables were measured and compared before and after treatment. A full periodontal evaluation was performed at the follow-up visit. Twenty-one patients enrolled with a mean treatment length of 7.9 ± 3.3 years. For the mandibular anterior teeth, clinical crown height did not change over the evaluated period. At follow-up, all the periodontal assessed variables were within normal limits, with the mean probing depth of 1.4 ± 0.5 mm, recession 0.6 ± 1.1 mm, and clinical attachment loss 0.8 ± 1.0 mm. Compared with baseline, there was a significant proclination of mandibular incisors (mean increase of 5.1 degrees) with the continued use of an oral appliance. Gingival levels were maintained with clinically insignificant changes during the observation period. Inclination of the mandibular incisors increases significantly with the use of an oral appliance in patients with obstructive sleep apnea. Positional changes in these teeth were not associated with any measured evidence of increase in clinical crown height or gingival recession. Heda P, Alalola B, Almeida FR, Kim H, Peres BU, Pliska BT. Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea. J Clin Sleep Med. 2021;17(10):2067-2074.

Comparison of Changes in Incisors Inclination and Dental Arch Dimensions in Damon and MBT Systems Using Dolphin Software

Background: There is great controversy regarding the effect of MBT and Damon bracket systems on dental arch dimensions and incisor position. Objectives: We aimed to study the effects of two different brackets (MBT and Damon) on dental arch dimensions and incisors position after orthodontic treatment. Methods: In this retrospective study, the records of 20 patients who underwent orthodontic treatment with MBT or Damon bracket systems were studied. All patients had class I skeletal and dental malocclusion and were treated without extraction. The patients were treated either with Damon or MBT bracket systems (n = 10). Lateral cephalograms were traced using the Dolphin software to determine the position of incisors. In addition, transverse dimensions of dental arches were measured on occlusal photographs. Fishers’ exact test, independent-test, Man-Whitney, paired t-test, and Wilcoxon were used for statistical analysis. P &lt; 0.05 was set as significant. Results: There was no significant difference between the two groups regarding age, sex, and initial values of the variables studied. U1-Apog (mm), upper inter-canine, lower inter-second premolar distance showed a significant difference before and after treatment in the Damon system. However, no significant difference was observed between initial and post-treatment values in the MBT group. L1-Apog (°), IMPA (°), maxillary inter-first and second premolars, inter-canine, and mandibular inter-canine distance was higher in the Damon system after treatment compared to MBT. Changes of the upper and lower transverse dimensions of the dental arches and the incisor positional did not reveal a notable difference in the Damon and MBT systems (P &gt; 0.05). Conclusions: There was no significant difference regarding changes in dental arches and incisor positions between the Damon and MBT systems.

Application of Microscrew Implant Anchorage in Orthodontics

Objective: To study the value of microscrew implant anchorage in orthodontic treatment. Methods: A total of 80 cases received orthodontic treatment in recent two years were selected and divided into experimental group and control group based on their received orthodontic measures, each group contains 40 cases. The control group was treated with general orthodontic treatment plan, while the study group received microscrew implant anchorage for the treatment. The clinical conditions of the two groups were counted and observed. Results: After different treatments, the effect of the study group was significantly better than that of the control group. All the indicators (including the improvement of molar displacement, incisor inclination angle and incisor convex distance) were available. In addition, there are obvious differences between the two groups in the occurrence of adverse reactions including inflammatory reaction, soft tissue edema and discomfort. Conclusion: In oral clinic, microscrew implant anchorage can achieve ideal curative effect for those who need orthodontics. Besides, its safety is relatively high, which is worth popularizing widely.

Effects of miniplate anchored Herbst appliance on skeletal, dental and masticatory structures of the craniomandibular apparatus: A finite element study

To analyze the stress distribution in the hard and soft tissue structures of craniomandibular complex during mandibular advancement with miniplate anchored rigid fixed functional appliance (FFA) using Finite Element Analysis (FEA). The virtual model consisting of all the maxillofacial bones (up to calvaria), the mandible and temporomandibular joint (TMJ) was generated using the volumetric data from pre-treatment CBCT-scan of a growing patient. The masticatory muscles, other soft tissues, Herbst appliance and plate geometry were modelled mathematically. Force vectors simulating muscle contraction at rest and advanced mandibular positions, with protraction force of 8N were applied. The final model was imported into ANSYS for analysis after assigning material properties. The maximum von Mises stress of 11.69MPa and 11.96MPa magnitude was observed in the region of pterygoid plates and at the bone-miniplate interface respectively, with the mandibular advancement of 7mm. Stress patterns were also noted at the condylar neck. The stress values observed in the medial and lateral pterygoid muscles were of 10.42MPa and 4.16MPa magnitude, respectively. Stress was noted in the bucco-cervical region of the upper posterior teeth, but negligible change was seen on the lower anterior teeth and periodontal ligament. Miniplate Anchored Herbst Appliance brought about Class II skeletal correction in growing children as it was accompanied by minimal changes in the inclination of the lower incisors. Soft tissue structures like pterygoid muscles and discal ligaments exhibited increased stress whereas masseter muscle displayed reduction in stresses.

Tooth Position in Wind Instrument Players: Dentofacial Cephalometric Analysis.

Background: Specific dentofacial characteristics in wind instrumentalists should be taken in consideration when analyzing physiological and anatomical issues regarding the musician’s embouchure, posture, and biomechanics during musical performance. Objectives: To compare tooth cephalometric characteristics between wind instrument players and string players (overjet, overbite, lower facial height, facial convexity, lower incisor inclination, and interincisal angle). Methods: In total, 48 wind instrumentalists (67%) and 24 string instrumentalists (33%). These musicians performed lateral tele-radiography and the correspondent linear and angular measurements of the dentofacial cephalometric analysis. Statistical comparison of wind and string instrumentalists was made by using an independent t-test. Results: Small variations on the analyzed parameters were found between the wind and string instrument groups. Based on the cephalometric analysis the variable interincisal angle was statistically significant (p < 0.05), when comparing the wind and string instrument group. Conclusions: Knowledge of the overjet and overbite value permits a substantial analysis on the tooth position of wind instrument players, where both of these parameters are increased and greater than the norm value. The cephalometry was an added value on the interpretation of possible factors that lead to the position of the central incisors of wind instruments. Till some extent in this group of musicians the applied forces during the embouchure mechanism on the anterior teeth and the existing perioral forces promote an equilibrium on the vector of forces. This study findings demonstrate that when evaluating the two samples, wind and string instruments there are different dentofacial configurations, however the only statistically significant differences that were found are related to the interincisal angle (p < 0.05).

Maxillary sagittal expansion in an adult patient

Relevance. Skeletal Class III malocclusion is known to be one of the most difficult malocclusions to correct. Nonsurgical treatment of Class III in adults is a challenge; however, this patient refused surgery. A treatment method with Fixed Anterior Growth Guidance Appliance (FAGGA) was investigated in the study.Materials and methods. This case report presents a 37-year-old woman with skeletal Class III malocclusion for maxillary deficiency. As the patient didn’t agree to surgery, she was treated by Fixed Anterior Growth Guidance Appliance, followed by 3D SMILE® clear aligners. Fixed Anterior Growth Guidance Appliance was used initially. After 4 months, the appliance was removed and clear aligner treatment was initiated. Post-treatment radiographs showed improvement.Results. Intraorally, in the upper arch, a total of 4.00 mm of space were gained (about 2.00mm distal to each canine). The post-treatment cephalometric analysis showed a skeletal A-P Class I, the Upper incisor inclination to the optic plane was not significantly altered, ANS — antArc was improved by 1.5mm, the Effective Length of the Premaxilla increased by 2.6mm, U1 — ANS’ decreased by 1.7mm, Incisor mandibular plane angle (IMPA) autonomously improved by 11 degrees.Conclusions. Maxillary deficiency was corrected successfully with the Fixed Anterior Growth Guidance Appliance. The treatment is being continued by 3D SMILE® clear aligners. The goal was achieved despite the patient’s age and nonsurgical treatment.

Dentofacial characteristics and age in association with incisor bony support in adult female patients with bimaxillary dentoalveolar protrusion.

The aim of this study was to analyse the correlation between incisor alveolar bone thickness (IABT) and dentofacial characteristics or age in adult female patients with bimaxillary dentoalveolar protrusion (BDP). Evaluating the contribution of these characteristics may help to predict the IABT differences in this patient population. A retrospective study whose sample comprised 80 pretreatment adult female patients with BDP (mean age 24.6years). The IABT of the bimaxillary central incisors was measured by cone-beam computed tomography. Among the types of IABT, the apical trabecular bone thickness was measured with a quantitative method. The sagittal skeletal pattern, facial divergence, the incisor inclination angle, and mandibular plane angulation were determined by cephalometric analysis. A backward linear multiple regression was performed to analyse the associations between IABT and these characteristics. Three dentofacial traits and age were associated with IABT. Patients with increased age and facial divergence tended to have a thinner mandibular incisor bone support, while increased root length was associated with a thicker mandibular incisor apical bone thickness. Increased U1-SN and facial divergence may lead to a thinner maxillary incisor palatal bone, while increased U1-SN resulted in a thicker maxillary incisor labial bone. The bony support of the incisors is associated with age and dentofacial traits. Increasing age and facial divergence are considered risk factors for alveolar defects in female patients with BDP. In contrast, increased root length is associated with a thicker mandibular incisor apical bone support.

One-Year Treatment Outcome of Profile Changes After Transcutaneous Maxillary Distraction Osteogenesis in Growing Children With Cleft Lip and Palate.

To evaluate the long-term stability of LeFort I osteotomy followed by distraction osteogenesis with a transcutaneous rigid external device for the treatment of severe maxillary hypoplasia in patients with cleft lip and palate. Nine patients with cleft lip and palate underwent rigid external distraction after a LeFort I osteotomy for maxillary advancement. Lateral cephalometric films were analyzed for assessment of treatment outcome and stability in 1 month, 6 months, and 1 year after distraction. Significant maxillary advancement was observed in the horizontal direction, with the anterior nasal spine (ANS) distance of the maxilla increasing by an average of 20.5 ± 5.1 mm after distraction. The ANS relapse rates in 6 months and 1 year were 8.7% and 12.8%, respectively. The mean inclination of upper incisors to the palatal plane was almost unchanged (before: 109.8° ± 6.6°; after: 108.9° ± 7.5°). The movement ratios at the nasal tip/ANS, soft tissue A point/A point, and the upper vermilion border/upper incisor edge were 0.36:1, 0.72:1, and 0.83:1, respectively. Considerable maxillary advancement was achieved with less change of incisors inclination after distraction. Moreover, the relapse rate after 1 year was minimal. The concave facial profile was improved as well as the facial balance and aesthetics.

Correction of class II div 2 malocclusion with simple yet effective modified sectional archwire: A case report

Class II div 2 is a marked category of Class II malocclusion with typical features like retroclined maxillary incisors and severe deep over bite, caused by both skeletal and dentoalveolar factors. This case report describes the orthodontic treatment of a 21 years old male, with permanent dentition, sagittal skeletal Class I pattern, Class I molar and canine relationship with class II div 2 incisor relationship. His chief compliant was irregularly placed teeth in upper front region of the jaw. The patient had convex profile, incompetent lips and deep mento- labial sulcus with 100% overbite. Treatment mostly consisted of inclination correction of the incisors and opening of the bite with the help of modified sectional archwire in the maxillary arch and double L-loop mandibular archwire. Satisfactory improvement in the patient’s esthetics was achieved along with improved overjet, overbite and inclination of incisors.

Изменение торка фронтальных зубов с оценкой толщины костной ткани на конусно-лучевом компьютерном томографе

Changing the vestibulo-oral inclination (torque) of the frontal teeth is an important component of orthodontic treatment. Cone-beam computed tomography is recommended as an accurate diagnostic tool allowing the orthodontist to estimate the safety of frontal tooth movement and inclination. This tool is helpful in measuring bone thickness at different levels of the tooth root and estimating incisal inclination and position. The aim of our study was to analyze bone thickness in patients with pathologically and normally inclined teeth using CT images and to create a universal table that will provide useful information about the thickness of the bone around different segment of the root required for a safe change in tooth inclination. Using the proposed table, the orthodontist can assess the feasibility of the planned tooth movement in the setting of changed tooth inclination, with due account of critical bone deficit regions. This will ensure the safety of tooth movement, stable retention and a positive treatment outcome.