Lower lip changes after overjet reduction with and without mandibular incisor retraction.

To compare lower lip changes after Le Fort I advancement surgery in patients with a cleft. Single institution, retrospective review. Academic tertiary referral hospital. Skeletally mature patients with a cleft who underwent one-piece Le Fort I advancement surgery who had a lateral cephalogram or cone-beam computed tomography (CBCT) scan preoperatively and at least 6 months postoperatively. Patients who underwent concomitant mandibular surgery or genioplasty were excluded. 64 patients were included: 45 male and 19 female, 25 with BCLP and 39 with UCLP. The mean age at surgery was 18.4 years. Single jaw one-piece Le Fort I advancement surgery. Standard lateral cephalometric landmarks of the bony skeleton and soft tissue were compared before and after Le Fort I advancement. Pearson correlation coefficients (r) were calculated to measure the correlation between lower lip position and other soft and hard tissue changes. After comparable maxillary advancements [BCLP: 7.2 mm (95% CI: 6.2-8.3 mm), UCLP: 6.4 mm (95% CI: 5.7-7.0 mm)] the horizontal upper-to-lower lip discrepancy significantly improved in both groups. The lower lip became thinner and more posteriorly positioned. Changes in lower lip position correlated strongly with mandibular bony landmarks and moderately with upper lip position, but poorly with maxillary landmarks. Le Fort I advancement results in posterior displacement of the lower lip and better lip competence, thereby improving facial harmony. This lower lip change is not predictable by degree of maxillary advancement, and does not differ in patients with BCLP vs. UCLP.

Space supervision and guidance of eruption in management of lower transitional crowding: A non-extraction approach

Effects of extraction and nonextraction therapy with air-rotor stripping on facial esthetics in postadolescent borderline patients

The incisor has a variation of root canal morphology, which can be assessed using periapical radiography. Periapical radiography with standard angulation often makes complicates the assessment of the root canal morphology that is branched off in buccal and lingual directions because the radiograph result of the root canal will appear superimposed. Therefore, it is necessary to change horizontal angulation to mesial or distal to help assess the superimposed root canal. Root canal morphology may vary by population. The population in Indonesia consists mainly of the sub-races of Proto and Deutro-Malay. The purpose of this study was to determine the difference of root canal morphology between maxillary and mandibular incisors; between the sub-races of Proto and Deutro-Malay; and between the right and left regions, using twice the radiation projection. This study was an analytical study with cross-sectional method using 55 subjects who come from three previous generations of Proto and Deutro-Malay. On each tooth were performed twice radiations periapical radiography, using standard angulation and altering horizontal angulation toward distal 30º. The results showed that in Proto-Melayu, for maxillary central incisors maxillary teeth were obtained type I (99.1%) and III (0.9%) Vertucci, and maxillary lateral incisors were obtained type I Vertucci (100%). In mandibular central incisors were obtained type I (90%), II (3.6%), III (2.7%) Vertucci and IV Gulabivala (3.6%), and mandibular lateral incisors were obtained type I (87.3 %), II (1.8%), III (7.3%) Vertucci and type IV Gulabivala (3.6%). In Deutro-Malay, maxillary central incisors were obtained 100% Vertucci type I and maxillary lateral incisors were obtained type I (99.1%) and II (0.9%). In mandibular central incisors were obtained type I (85.5%), III (11.8%) Vertucci, IV Gulabivala (1.8%), and other types 1-2-1-2-1 (0.9%), and mandibular lateral incisors were obtained by type I (81.8%) and III (18.2%) Vertucci. The result of chi-square analysis showed there were no significant differences of root canal morphology of maxillary insicors tooth between Proto and Deutro-Malay and between right and left region (p> 0,05), but there were significant differences of root canal morphology between maxillary and mandibular incisors and root canal morphology of the mandibular incisor between Proto and Deutro-Malay (p <0.05). In conclusion, maxillary and mandibular incisors of Proto and Deutro-Malay sub-races have variations in root canal configuration and there were differences found in the mandibular incisors.

Objective: This study aims to evaluate the correlation between soft tissue adaptation and the retraction of incisors in Class II Division 1 malocclusion patients treated with fixed appliances and premolar extractions. Materials and Methods: Thirty-one patients underwent orthodontic treatment with fixed edgewise mechanics and four premolar extractions. Cephalometric analyses were conducted to assess soft tissue changes relative to incisor movements. The correlation of soft tissue landmarks with horizontal and angular changes of incisors was analyzed using Spearman’s correlation coefficient. Statistical significance was set at p < 0.05. Results: Strong positive correlations were observed between the retraction of the maxillary incisor tip (U1-y) and upper lip (Ls-y, r = 0.887, p < 0.001) and lower lip (Li-y, r = 0.765, p < 0.001) positions. Point A (A-y) also showed a strong positive correlation with U1-y (r = 0.907, p < 0.001). No significant correlation was found between nasolabial angle and U1-y. Changes in upper incisor inclination relative to the NA plane were negatively correlated with the nasolabial angle (r = -0.474, p = 0.007). Mandibular incisor retraction (L1-y) demonstrated significant positive correlations with lower lip (Li-y, r = 0.757, p < 0.001), upper lip (Ls-y, r = 0.810, p < 0.001), point B (B-y, r = 0.785, p < 0.001), and Pogonion (Pog-y, r = 0.749, p < 0.001). Conclusions: Soft tissue adaptation is closely correlated with the horizontal retraction of both upper and lower incisors. These findings emphasize the importance of evaluating soft tissue responses in orthodontic treatment planning to optimize aesthetic outcomes.

Objectives:To study the association between gingival biotypes and inclination and position of the maxillary and mandibular incisors.Methods:This cross-sectional study included 142 consecutive orthodontic patients (64 males and 78 females) who were seeking orthodontic treatment at the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia from February 2013 to January 2014. Gingival biotype was assessed independently for the maxillary and mandibular central incisors using the transparency of periodontal probe method. Maxillary and mandibular incisors’ inclination and position were measured using cephalometric analysis.Results:The mean age was 23.56 (±2.55) years. The prevalence of thin gingival biotype was 43% for the maxillary and 52.1% for the mandibular incisors. Females were 4 times more likely to have thin gingiva for the maxillary incisors and 5 times more likely for the mandibular incisors. A significant association was found between mandibular incisor inclination and position and thin gingival biotype, while there was no association between the maxillary incisor inclination and position and gingival biotypes.Conclusion:Mandibular incisor proclination and protrusion is associated with thin gingival biotype while no association is found in the maxilla. The evaluation of the gingival biotype is essential during diagnosis and treatment planning for potential orthodontic patients.

Changes in soft tissue profile following mandibular set back were investigated with lateral cephalograms of 40 patients initially having mandibular prognathism. Soft tissue profiles were evaluated using the analysis methods reported by Legan and Burstone, Ricketts, and Merrifield. Differences of the measurements before and after surgery were calculated as changes in profile produced by surgery, and following studies were made.1. The average changes in profile were analysed and the results were as follows: 1) Facial convexity improved, 2) Mandibular prognathism decreased, 3) No change in maxillary prognathism, 4) Posterior displacement of the upper lip with elongation and increase in upper lip protrusion, 5) Nasolabial angle increased, 6) Decrease in lower lip protrusion, 7) Lower facial height decreased, 8) Vertical lip-chin ratio improved, 9) Labiomental sulcus depth increased.2. The principal component analysis was employed in order to qualify the changes in profile as composition of several patterns.The analysis resulted in four principal components having 85% of accumulated contribution ratio.1) The first component (37.9%) is indicative of over-all quantitative change in profile by surgery.2) The second (23%) is indicative of displacement of the upper lip and change in lower lip protrusion.3) The third (14%) is indicative of changes in height of the lower lip and lower facial height and in the nasolabial angle.4) The fourth (10%) is indicative of change in the depth of the labiomental sulcus.Since there is no correlation among components in a principal component analysis, the second and third components in this study suggest the qualitative patterns of profile change. Therefore, changes in profile vary in the height of the lips and lower face and lower lip protrusion, based upon the averaged over-all changes.

This study was conducted to determine accuracy, precision and repeatability of four different methods for assessing gingival thickness METHODS: This cross-sectional study evaluated gingival thickness on 200 consecutively included orthodontic patients. Gingival thickness was assessed at both central mandibular incisors with: 1) transgingival probing with a standard periodontal probe, 2) transgingival probing with a stainless-steel acupuncture needle, 3) ultrasound, and 4) a color-coded periodontal probe. Intra-examiner reproducibility and method error were also evaluated. Transgingival measurements with the standard periodontal probe were found to be more accurate than those with the acupuncture needle, after method error assessment. Acupuncture needle and ultrasound device yielded higher values than the probe. Expected differences between the two methods were 22% more for the mandibular left central incisor (95% confidence interval (CI)=11% to 32%) and 26% more (95% CI=13% to 39%) for the mandibular right central incisor when measured with the needle. Ultrasound measurements exceeded probe measurements on average by 0.16mm at mandibular left central incisor (95% CI=0.14 to 0.18) and by 0.11mm for mandibular right central incisor (95% CI=0.08 to 0.13). Intraclass correlation coefficient concluded good agreement for the color-coded periodontal probe (0.624). Within the inherent limit of the uncertainty about the true value of gingival thickness, the present results demonstrate the differences between the tested methods, as far as accuracy and reproducibility are concerned. Based on the reproducibility, the transgingival probing with the periodontal probe as well as the ultrasound determination, seem to present an adequate choice for every day practice.

INTRODUCTIONAdditional canals are frequent findings in radicular morphology of the mandibular incisors. Finding additional canals and their obturation significantly improve the prognosis of endodontic treatment. Cone Beam Computed Tomography (CBCT) best visualize all canals and their configurations. The study assessed root canal anatomy of mandibular incisors on CBCT images of the patients. MATERIAL AND METHODSAn observational cross-sectional study was carried during July-October 2021 on 42 CBCT images of the patients visiting Kantipur Dental College and Hospital. The samples were selected using convenience sampling presenting with bilateral mandibular central and lateral incisors. Root canals and their configurations were assessed on 168 teeth. The presence of unilateral or bilateral additional root canal was recorded and chi-square test was used to test its association with gender (p < 0.05). RESULTThe prevalence of additional canal was 27.4% in mandibular incisors. Bilateral symmetrical distribution of extra canal in mandibular central and lateral incisors were 36.3% and 41.6% respectively. There was a significant association between the presence of extra canal and gender in both central incisors (p-value 0.019) and lateral incisors (p-value 0.009). Type I canal configuration was most prevalent (72.6%) followed by Type III (22.6%). CONCLUSIONThe prevalence of double canals in mandibular incisors is 35% in male and 4% in female samples confirming the male predominance. Bilaterally symmetrical occurrence of double canal is evident up to 41%. CBCT evaluation helps in the visualization of missing root canals during endodontic therapy.

To investigate the root canal's anatomy, gender differences, and bilateral symmetry of permanent mandibular incisors using cone-beam computed tomography (CBCT). A total of 208 patients with 822 well-developed mandibular incisors were evaluated. CBCT images were retrieved from the database of patients who received treatment in the College of Dentistry and Dental Clinics. The following parameters were evaluated using CBCT: (1) the number of roots; (2) the number of canals; (3) canal configuration according to Vertucci's classification; (4) differences between genders; and (5) bilateral symmetry. Two canals appeared in 26.3% of mandibular central incisors, 30.8% of lateral incisors, and 28.6% of all the 822 mandibular incisors. In the teeth with two canals, Type III configuration was dominant. There were no statistically significant differences found between the central and lateral incisors (P = 0.449). There were gender differences in central incisors, while lateral incisors showed none. Slight bilateral asymmetries appeared in central and lateral incisors in relation to some canals and canals configurations. CBCT can be of great use in locating the second canal and determining canal configuration in mandibular incisors. Knowledge of bilateral asymmetry can be of clinical significance when the clinician is treating contralateral teeth in the same patient.

IntroductionThis cross-sectional study assessed the influence of patient demographics on the worldwide prevalence of a lingual canal in mandibular incisors. MethodsTwenty-six thousand four hundred mandibular incisors were evaluated using cone-beam computed tomography imaging by precalibrated observers from 44 countries. A standardized screening method was employed to collect data on the presence of a lingual canal, the anatomic configuration of the root canal, and number of roots. Patient demographic information (age, sex, and ethnicity) was also recorded. Multiple intra and interrater tests assessed the reliability of the observers and groups, and a meta-analysis was used to examine differences and heterogeneities (α = 5%). ResultsThe prevalence of the lingual canal in mandibular central and lateral incisors varied from 2.3% (0.06%–4.0%; Nigeria) to 45.3% (39.7%–51.0%; Syria) and from 2.3% (0.06%–4.0%; Nigeria) to 55.0% (49.4%–60.6%; India), respectively. Ethnicity had a significant impact on the prevalence of the lingual canal, with African, Asian, and Hispanic groups having the lowest proportions (P < .05), while Caucasians, Indians, and Arabs showed the highest (P < .05) for both incisor groups. Additionally, males had a significantly higher odds ratio for both the central (1.334) and lateral (1.178) incisors, while older patients had a lower prevalence for both tooth groups (P < .05). The side and tooth group did not influence on the outcomes. ConclusionsThe prevalence of lingual root canals in mandibular incisors varies significantly based on geographic location, ethnicity, age, and gender. The overall prevalence was 21.9% for mandibular central incisors and 26.0% for lateral incisors.

To investigate the compensation of the upper and lower incisors in skeletal Class III patients treated with orthodontic-surgical approach. The samples consisted of 54 skeletal Class III patients treated with orthodontic-surgical approach from November 2011 to January 2015. Lateral cephalograms were taken before treatment. The differences between the samples and the norms from Peking University normal occlusion sample library were assessed using independent-sample t test. Correlation analyses were performed to find associations between skeletal and dental parameters. According to skeletal anteroposterior discrepancy/vertical type (ANB/SN-MP), the samples were allocated into group A (ANB < -4°, SN-MP ≤ 37.7°, n = 11), group B (ANB ≥ -4°, SN-MP ≤ 37.7°, n = 16), group C (ANB < -4°, SN-MP > 37.7°, n = 14), and group D (ANB ≥ -4°, SN-MP > 37.7°, n = 13). After measurement of variables, one-way ANOVA with SNK multiple comparison test were performed. The maxillary incisors were more proclined and the mandibular incisors more retroclined in skeletal Class III patients compared with norm values (P < 0.01). Both skeletal anteroposterior discrepancy and vertical type were correlated with the position of upper and lower incisors (P < 0.01). According to skeletal anteroposterior discrepancy/vertical type, no significant differences were found in the upper incisors' inclination among the four groups, while patients in group A and group D exhibited significant difference in lower incisor compensation. Different skeletal anteroposterior discrepancy/vertical type resulted in varied incisors' compensation. Therefore, decompensation should be treated differently.

Commentary

ABSTRACTAim:The purpose of this study was to assess the short-term perioral soft tissue variations of the lips before and after treatment cases in 15 patients with bi-maxillary protrusion using treated lateral cephalograms who had already achieved active growth.Methodology:Fifteen pre-treatment and post-treatment lateral cephalometric radiographs of 18–25-year-old individuals with bimaxillary protrusion treated with all four 1st premolar extractions were accessed from the records. From the reference planes and landmarks, 13 horizontal, 10 vertical, and 2 angular measurements were noted. Statistical comparisons between pre-treatment and post-treatment measurements were measured by a paired t-test to assess the importance of the mean variations at the predetermined significance level. Pearson’s correlation coefficient (R) was utilized to assess the strength and significance of the linear relationship between the mean differences for paired (dependent and independent) variables.Results:Pearson’s correlation exhibited a noteworthy positive association between the horizontal changes in upper lip position and the horizontal changes of the upper incisor tip point (H-tU1) (R = 0.748), the upper incisor cervical point (H-cU1) (R = 0.707), the lower incisor tip point (H-tL1) (R = 0.839), and the lower incisor cervical point (H-cL1) (R = 0.767). This indicated that upper lip changes are the aftermath of the retraction of the upper and lower incisors in class I bi-maxillary protrusion malocclusion.Conclusion:Thick upper lips showed more retraction of the upper lip in correlation with retraction of the incisors as compared with thin lips. The lower incisor cervical point displayed the strongest association with lower lip retraction.

Class II subdivision malocclusion