Bimaxillary Protrusion Research Articles

Improved facial profile with non-extraction treatment of severe protrusion using TSADs

Extraction has traditionally been necessary to correct bimaxillary and lip protrusion with proclined maxillary and mandibular incisors. However, non-extraction treatment using temporary skeletal anchorage devices (TSADs) is now an option for severe overjet or full-step Class II malocclusions. It is possible to treat bimaxillary protrusion with non-extraction, but for successful non-extraction treatment in bimaxillary patients, the amount of total arch distalization of the mandibular dentition is crucial.For maximum total mandibular arch distalization in protrusion patients, it is recommended to extrude and distalize the molars simultaneously, which results in more posterior movement of the mandibular dentition without gingival impingement. Therefore, this paper presents efficient biomechanics, a strategy, and the anatomy of the retromolar area for total arch distalization using TSADs to improve facial profile without extracting premolars in Class II maxillary and bimaxillary protrusion patients.

Shape Visualization of Dental Inclination in Class I and Bimaxillary Protrusion Malocclusions through Geometric Morphometric Analysis

Objectives: This study aimed to determine the shape of dental inclination between Class I malocclusion and bimaxillary protrusive Malay patients using geometric morphometric analysis obtained from lateral cephalometric radiographs. Materials and Methods: 128 Malay patients who met the inclusion criteria were recruited; of which 64 patients were in Class I malocclusion and another 64 patients in bimaxillary protrusion groups. Samples were in the age range of 18 to 40 years old, with a gender distribution of 41 males and 87 females. Pre-treatment orthodontic lateral cephalometric radiograph were traced and digitized. Thirteen landmarks of each radiograph were incorporated and converted into coordinates using TPSUtil software. The plots were then exported to MorphoJ Software for multiple Geometric Morphometric Analysis (GMA). Results: The results showed that there was a statistically significant difference (p<0.01) in shape of dental inclination between the groups. Discriminant analysis and cross validation of these groups demonstrated 98% accuracy in identifying two types of dental malocclusion. The grid graphs illustrated the shape of dental inclination of the bimaxillary protrusion group as being significantly more proclined when compared to Class I malocclusion. Conclusion: This study concludes that the dissimilarities in dental inclination are identifiable in Class I malocclusion and bimaxillary protrusion and the shape differences can be visualized using geometric morphometric analysis.

Labial and palatal alveolar bone changes during maxillary incisor retraction at the Universitas Sumatera Utara Dental Hospital

Background: The fundamental concept of tooth movement during orthodontic treatment is the occurrence of bone remodelling accompanied by tooth movement in equal proportions. The thickness of the alveolar bone, which supports incisors, is important in estimating the direction of tooth movement. Purpose: The study aimed to measure labial and palatal alveolar bone thickness changes after maxillary incisor retraction using lateral cephalograms. Methods: Cephalograms of 40 patients (18.58 ± 4.2 years) with skeletal Class I bimaxillary protrusion after maxillary first premolar extraction for insisivus retraction had been taken before (T0) and after (T1) orthodontic treatment. Changes in alveolar bone thickness were measured in linear and angular directions and then analysed with Spearman correlative analysis. Then the samples were separated into two groups based on the type of tooth movement (tipping and torque), and then the data were analysed using Wilcoxon analysis to see differences in the bone thickness (p<0.05). Results: There was a significant difference in the apical palate (p<0.05) and a relationship between retraction and alveolar bone thickness in the midroot area. In the angular direction, there was no significant difference and relationship; however, there was a significant difference in the labial crestal in the tipping group. In the torque group, the difference in bone thickness occurred in the crestal and apical palatal areas. Conclusion: The retraction and the type of tooth movement difference influence the alveolar bone thickness.

The role of anterior segmental osteotomies in orthognathic surgery for protrusive faces in a Southeast Asian population: 10-year retrospective data of 51 patients treated in a single centre

Bimaxillary protrusion is a dentofacial deformity common in the East Asian population. It is often difficult to decide between orthodontic and surgical retraction to treat patients with bimaxillary protrusion, especially if surgery to correct skeletal base discrepancies is also required. The objective of this study was to investigate the treatment outcomes of surgical versus orthodontic retraction in patients with bimaxillary protrusion undergoing orthognathic surgery. A retrospective cohort study was conducted, where the medical records and radiographs of 51 patients with bimaxillary protrusion who had an anterior segmental osteotomy concomitant with orthognathic surgery were examined. Patients who had bimaxillary anterior segmental osteotomies were more likely to achieve an inter-incisal angle of 135 ± 5° at the end of treatment, when compared to patients who had orthodontic retraction (P < 0.01). The total treatment duration of patients who had bimaxillary anterior segmental osteotomies was significantly shorter as compared to that of the patients who only had these osteotomies in the maxilla (P < 0.001) or mandible (P = 0.012). Complications and permanent long-term sequelae following anterior segmental osteotomies were uncommon. It is concluded that bimaxillary anterior segmental osteotomies are a viable alternative for patients with concomitant bimaxillary protrusion and skeletal base discrepancies. This allows for a significantly shorter treatment time and greater correction of inter-incisal angles, without a significant increase in complications.

Comparison of Salivary Leptin Levels Between Underweight and Overweight Individuals and Its Role in Orthodontic Tooth Movement

Introduction: The Aim of this study is to compare the concentration of salivary leptin levels between underweight and overweight individuals and its significance in orthodontic tooth movement. Methods: Fourty five underweight and overweight female subjects. Materials and Method: Fourty five underweight and overweight female subjects were taken in this study and they are divided into two groups, group I (underweight) and group II (overweight) depending on their mean body mass index. Angles class I malocclusion with bimaxillary protrusion were taken into this study. All subjects underwent upper first premolar extraction, and distal force is applied with lacebacks to maxillary canine. Salivary leptin samples were collected before force application (To), one hour after appliance placement T2, and one month after appliance placement (T3). Result: Overweight individuals show increased salivary leptin concentration three times greater than underweight individuals. Orthodontic tooth movement is decreased in overweight individuals when compared with underweight individuals. Conclusion: Increased salivary leptin levels showed a decreased tooth movement in overweight individuals than underweight individuals who showed decreased salivary leptin levels. Obese individuals require more orthodontic treatment duration time when compared with lean individuals.

Stepladder plating following lower subapical and genioplasty procedure in patients with bimaxillary protrusion having short chin: A technical note

Stepladder plating following lower subapical and genioplasty procedure in patients with bimaxillary protrusion having short chin: A technical note

Soft tissue changes with skeletal anchorage in comparison to conventional anchorage protocols in the treatment of bimaxillary proclination patients treated with premolar extraction : Asystematic review.

This review systematically evaluates the evidence related to comparisons between skeletal and conventional anchorage protocols in the treatment of bimaxillary proclination patients who underwent premolars extraction with respect to soft tissue profile changes, treatment duration and three-dimensional (3D) soft tissue changes. Electronic database search and hand search with no language limitations were conducted in the Cochrane Library, PubMed, Ovid, Web of Science, Scopus and ClinicalTrials.gov. The selection criteria were set to include studies with patients aged 13years and above requiring extractions of upper and lower first premolars to treat bimaxillary proclination with high anchorage demand. Risk of bias assessment was undertaken with Cochrane's Risk Of Bias tool 2.0 (ROB 2.0) for randomised controlled trials (RCTs) and ROBINS‑I tool for nonrandomised prospective studies. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used for quality assessment. Results were summarised qualitatively; no meta-analysis was conducted. Two RCTs and two nonrandomised prospective studies were included. According to the GRADE approach, there is low to very low quality of evidence that treatment using mini-implant anchorage may significantly change nasolabial angle, upper and lower lip procumbence, and facial convexity angle compared to treatment with conventional anchorage. Similarly, very low quality evidence exists showing no differences in treatment duration between treatments with skeletal or conventional anchorage. The overall existing evidence regarding the effect of anchorage protocols on soft tissue changes in patients with bimaxillary protrusion and premolar extraction treatment plans is of low quality. PROSPERO CRD42020216684.

Bimaxillary protrusion: A literature review

Introduction: Bimaxillary protrusion is an occlusal feature characterized by protrusive and proclined upper and lower incisors, associated with increased flattening of the lips and greater than average degree of lip prominence. It is considered one of the malocclusion types that stimulate patients to seek orthodontic treatment to improve facial symmetry. Objective: To conduct a literature review on bimaxillary protrusion with respect to its aetiological factors, morphological features, prevalence, diagnosis, and management. Methods: Relevant sources of information were searched using electronic databases including Google Scholar, PubMed, Elsevier, ResearchGate, and Web of Science. A total of 28 articles were considered and included in the literature review. Results: It was observed that bimaxillary proclination is prevalent among Asian, African, African-American, and the Caribbean regions, but less prevalent in white Caucasian populations. Treatment of patients with bimaxillary protrusion by extraction of four premolars was found to be successful in decreasing the dental and soft tissue procumbency seen in patients with bimaxillary protrusion. Conclusion: Successful treatment of patients with bimaxillary protrusion starts with a good understanding of the patient’s concerns and sometimes, a close collaboration between an orthodontist and an oral surgeon.

Evaluation of anchorage loss following anterior segment Evaluation of anchorage loss following anterior segment retraction using friction versus frictionless mechanics: a retraction using friction versus frictionless mechanics: a randomized clinical trial

Objective: Evaluation of anchorage loss following anterior segment retraction (ASR) using friction versus frictionless mechanics when mini-screws are directly and indirectly loaded using Cone beam computed tomography (CBCT). Material and methods: Thirty females with bimaxillary protrusion were randomly allocated into two groups, friction and frictionless. In friction group, a hook was crimped on 0.017- by 0.025-inch stainless steel wire distal to the lateral incisor and elastomeric chain rendering 160 g/side extending between the hook and mini-screw implant to complete the ASR. In the frictionless group, canines were ligated to the mini-screws for indirect anchorage then ASR was done using closing T-loops fabricated from 0.017- by 0.025-inch titanium molybdenum alloy (TMA) wire rendering comparable retraction force. Analysis of first molar anchorage loss in terms of bodily and angular movement were assessed using cone beam computed tomographic (CBCT) images. Results: The use of mini-screws prevented significant anchorage loss in both groups and ASR was accomplished successfully. Anchorage loss in the form of angular tipping was of no statistical significance between friction and frictionless group. Conclusion: No advantage of either mechanics over the other regarding anchorage loading on the first permanent molars. Mini-screws are efficient devices to control the anchorage. Both direct and indirect mini-screw anchorage prevented first permanent molar mesial tipping and can be use alternatively.

Difference in the alveolar bone remodeling between the adolescents and adults during upper incisor retraction: a retrospective study

The purpose of this study was to compare the difference of alveolar bone remodeling between the adolescents and adults in the maxillary incisor area during retraction. This retrospective study included 72 female patients who needed moderate anchorage to correct the bimaxillary protrusion. Subjects were further divided into the minor group (n = 36, 11–16 years old) and adult group (n = 36, 18–35 years old). Digital lateral cephalography and cone beam CT scanning were taken in each patient before (T0) and after treatment (T1). Cephalometry was conducted to assess incisor retraction, while alveolar bone thickness (ABT), alveolar bone distance (ABD), and alveolar bone area (ABA) were detected to assess changes in the alveolar bone. No difference in the inclination of upper incisors was observed at both T0 and T1 between two groups. Changes in the alveolar bone showed a similar tendency with bone apposition on the labial side and bone resorption on the palatal side in both groups. Less increase in the labial ABT (T1–T0) and more decrease in the palatal ABT (T1–T0) was found in the adult group, leading to less total ABT in the adult group. Higher reduction in ABD (T1–T0) was found in the adult group. Moreover, more decrease in the ABA (T1–T0) was found in the adult group. Adult patients have less alveolar bone support after treatment when compared with young adolescents. Orthodontists should take the age into consideration to reduce the potential periodontal risks during the treatment planning.

T loop mechanics for effective space closure in bimaxillary dentoalveolar protrusion - A case report

This case report intends to highlight the space closure with continuous T-loop mechanics for bimaxillary protrusion. Loops can be fabricated in a sectional or full arch wire, and closing loops are usually used in loop mechanics for extraction space closure. The major advantage of loop mechanics is the lack of friction between the bracket and arch wire during space closure. A 21-year old adult male patient with bimaxillary protrusion and spacing reported to the clinic. The patient was treated successfully by maximum retraction of maxillary and mandibular anterior teeth after extraction of all first premolars. Space closure was achieved using a moment differential between posterior and anterior segments created by a T-loop. A stable result with normal over jet and overbite was achieved with retraction of maxillary and mandibular anterior teeth and no loss of anchorage.

Long-Term CBCT Evaluation of Mandibular Third Molar Changes after Distalization in Adolescents

Introduction: This study aimed to evaluate mandibular molar changes after distalization using Class III elastics and modified C-palatal plates (MCPPs) in the maxilla and to use CBCT to specifically analyze the third-molar position after long-term retention in adolescents. Methods: The sample consisted of 65 mandibular third molars from 35 subjects, divided into two groups. Twenty-six of the third molars were from fourteen adolescent patients with Class I bimaxillary protrusion (mean age, 12.8 years) who had undergone bilateral maxillary distalization using an MCPP and mandibular distalization with Class III elastics with non-extraction treatment. For the control group, 39 third molars from 21 Class I normal-occlusion subjects were used. In the treated group, CBCT images were taken before distalization (T1), after molar distalization (T2), and at a long-term observation point (6.1 ± 2.7 years) (T3). Repeated measures ANOVA and a post hoc test with Bonferroni correction were used to analyze significant differences in the positions at the three points in time. Results: There were 2.3 and 1.7 mm of distal movement at the crown of the mandibular first and second molars, with distal tipping of 5.2° and 5.3°, respectively, and 3.0° of distal tipping of the third molars. Comparing the treated group with the control group at T3, there was a significant change in the angulation of the third molars (p &lt; 0.001). In the long-term, the third molars from the treated group showed a downward and buccal position after distalization. Conclusions: In the long term, the developing mandibular third molar buds had downward and buccal positional changes after total arch distalization. These findings suggest the need for clinicians to consider the possibility of the impaction of developing third molars after mandibular total arch distalization in adolescents.

Effect of platelet-rich plasma on the rate of orthodontic tooth movement

This study aimed to evaluate the effect of platelet-rich plasma (PRP) on the rate of orthodontic tooth movement (OTM) during en-masse anterior retraction. Twenty adult patients with Angles Class I bimaxillary protrusion or crowding requiring first premolar extraction for routine orthodontic treatment were divided into control and experimental groups. The control group did not receive PRP, whereas the experimental group received PRP in the alveolar mucosa of the maxillary 6 anterior teeth just before starting en-masse retraction. Measurements were recorded on digital models made from scanned plaster casts at the beginning of space closure and the end of 3 months. The overall rate of OTM between both groups was compared. The amount of anchorage loss and type of anterior retraction on lateral cephalogram was also compared between the groups. The overall rate of OTM was minimally increased but not statistically significant in the experimental vs control group (P= 0.838). Anterior retraction parameters in both groups showed incisors moving primarily by controlled tipping and partly by translation. An intergroup comparison of all cephalometric parameters for anchorage loss and anterior retraction showed statistically insignificant differences between both groups. PRP is ineffective in accelerating the rate of OTM during en-masse anterior retraction.

Orthodontic Treatment of Severe Bimaxillary Dentoalveolar Protrusion with Skeletal Class II Malocclusion Without Using Miniscrews

Bimaxillary dentoalveolar protrusion is characterized by the proclined anterior teeth, protrusive lips, and a convex profile. A proper orthodontic treatment modality for efficient anchorage control is necessary to retract the anterior teeth and improve the facial esthetics significantly. The commonly used miniscrew could provide absolute anchorage, however, it is accompanied by some risks and complications, especially in adolescent females. This case report described a 16-year-old female with diagnosis of skeletal Class II, normal mandibular plane angle, and Angle Class I malocclusion associated with proclined upper and lower anterior teeth, excessive overjet, and a convex profile with lip incompetence. We extracted her four first premolars first. Then, the Tip-Edge Plus bracket system and differential force method were applied to replace the temporary anchorage device. The total treatment duration was 27 months. Her dentoalveolar protrusion was decreased, both lips were significantly retracted, the mentalis strain was reduced, and her chin projection was improved. This case demonstrated that differential tooth movement with controlled light orthodontic forces could be an effective strategy to treat severe bimaxillary protrusion.

Skeleto-dental features among a sample of Saudi female children compared to British standards: A cephalometric study.

This cross-sectional observational retrospective study aimed at assessing the cephalometric skeleto-dental features of class I, II, and III skeletal relationship of Saudi female school children sample and comparing the results to the established British Caucasian cephalometric standards. The sample consisted of 205 retrospective lateral cephalometric radiographs of female school children. The age range of the subjects were between 10 and 13 years old with a mean age of 11 ± 1 years. Several cephalometric and constructed points were identified. Angular, linear, and proportional measurements were obtained and analyzed. The skeleto-dental features of class II and class III were compared to class I of this sample and then compared with the established British Caucasian population. Different angular, linear, and proportional variables were investigated. Descriptive statistics and Student's t-test were used for data analysis. The distribution of the skeletal relationship revealed that 68.3% of the sample showed class I relationship, 16.1% class II, and 15.6% class III. The result indicates significant differences among the different classes. A greater tendency towards class II facial pattern and more convex profile among Saudis were detected in the present study compared to Caucasians. Furthermore, The dento-alveolar relationship results showed more bi-maxillary protrusion among Saudi females compared to the British Caucasians. The results of the study can serve as a base-line for future investigations in Saudi Arabia. Furthermore, the results obtained can also be of great value in distinguishing the various skeleto-dental features in the different skeletal classes among the Saudi females, and in the clinical diagnosis and treatment planning.

Evaluation and Comparisons of Steiner's Analyses in Class I, Class II, and Class III Patients of Central India as an Aid in Orthodontic Treatment Plan

Background: Cephalometric values particular to one ethnic group may not be applicable to others. Purpose: The purpose of the study was to evaluate and compare Steiner's analyses in Class I, Class II, and Class III patients of Central India in two different age groups. Materials and Methods: Sample size comprised 240 patients belonged to Central India. Patients were divided into two main groups: Group I comprised 120 young children in age of 12–16 years and Group II comprised 120 young adults in age of 18–22 years. Steiner's analysis was done from the data collected to assess skeletal and dental parameters. Results: Central Indian patients had bimaxillary dentoalveolar protrusion, particularly predominant in Class I and Class II males and Class III females. Central Indian patients had predominant retrognathic jaws in comparison to Caucasian norms. Conclusions: The differences of skeletal and dental parameters indicate that Caucasian norms cannot be truly adhered to Central India patients during orthodontic treatment. Incisors were normally more proclined in Central Indian patients and their overretraction during orthodontic treatment would cause flattening of facial profile and therefore should be avoided.

Comparison of salivary leptin levels between underweight and overweight individuals and its role in orthodontic tooth movement

Introduction: The Aim of this study is to compare the concentration of salivary leptin levels between underweight and overweight individuals and its significance in orthodontic tooth movement. Methods: Fourty five underweight and overweight female subjects were taken in this study and they are divided into two groups, group I (underweight) and group II (overweight) depending on their mean body mass index. Angles class I malocclusion with bimaxillary protrusion were taken into this study. All subjects underwent upper first premolar extraction, and distal force is applied with lacebacks to maxillary canine. Salivary leptin samples were collected before force application (To), one hour after appliance placement T2, and one month after appliance placement (T3). Results: Overweight individuals show increased salivary leptin concentration three times greater than underweight individuals. Orthodontic tooth movement is decreased in overweight individuals when compared with underweight individuals. Conclusions: Increased salivary leptin levels showed a decreased tooth movement in overweight individuals than underweight individuals who showed decreased salivary leptin levels. Obese individuals require more orthodontic treatment duration time when compared with lean individuals.

Changes in Facial Profile after Modified Anterior Maxillary Subapical Osteotomy.

(1) Background: This study explored the effects of modified anterior maxillary subapical osteotomy (AMSO) on facial profile changes in patients with bimaxillary protrusion. (2) Methods: Cephalograms of patients were collected preoperatively and over 2 months postoperatively. The following landmarks were recorded: pronasale (Prn), subnasale (Sn), labrale superius (Ls), anterior nasal spine (ANS), and incisor superius (Is). The following distances and angles were measured: ANS–Prn, ANS–Sn, ANS–Ls, Is–Sn, Is–Ls, SNA angle, and nasolabial (NLA) angle. (3) Results: Is and ANS were significantly retracted by 7.3 and 2.3 mm, respectively. Soft tissue landmarks (Prn, Sn, and Ls) were significantly retracted (1.2, 1.6, 4.4 mm, respectively). Postoperative changes in soft/hard tissue ratios were 0.54, 0.72, 0.31, and 0.60 for Prn/ANS, Sn/ANS, ANS/Is, and Ls/Is, respectively. The NLA angle was increased significantly by 7.1°. (4) Conclusions: The horizontal soft/hard tissue ratios of Sn/Is, ANS/Is, and Ls/Is were 0.22, 0.31, and 0.60, respectively. The NLA angle was increased significantly by 7.1°. The modified AMSO provides an increased blood supply, allows for direct vision, and results in fewer complications than other AMSO methods.

Mini screws – An absolute anchorage for en-mass retraction of bimaxillary dentoalveolar protrusion: A case report

Mini screws – An absolute anchorage for en-mass retraction of bimaxillary dentoalveolar protrusion: A case report - JCO- Print ISSN No: - Online ISSN No:- 2582-0478 Article DOI No:- 10.18231/j.jco.2021.006, Journal of Contemporary Orthodontics-J Contemp Orthod

Three-Dimensional Digital Image Analysis of Skeletal and Soft Tissue Points A and B after Orthodontic Treatment with Premolar Extraction in Bimaxillary Protrusive Patients.

Aim. To investigate the effect of changes in incisor tip, apex movement, and inclination on skeletal points A and B and characterize changes in skeletal points A and B to the soft tissue points A and B after incisor retraction in Angle Class I bimaxillary dentoalveolar protrusion. Methods. Twenty-two patients with Angle Class I bimaxillary dentoalveolar protrusion treated with four first premolar extractions were included in this study. The displacement of skeletal and soft tissue points A and B was measured using cone-beam computed tomography (CBCT) using a three-dimensional coordinate system. The movement of the upper and lower incisors was also measured using CBCT-synthesized lateral cephalograms. Results. Changes in the incisal tip, apex, and inclination after retraction did not significantly affect the position of points A and B in any direction (x, y, z). Linear regression analysis showed a statistically significant relationship between skeletal point A and soft tissue point A on the anteroposterior axis (z). Skeletal point A moved forward by 0.07 mm, and soft tissue point A moved forward by 0.38 mm, establishing a ratio of 0.18: 1 (r = 0.554, p &lt; 0.01). Conclusion. The positional complexion of the skeletal points A and B was not directly influenced by changes in the incisor tip, apex, and inclination. Although the results suggest that soft tissue point A follows the anteroposterior position of skeletal point A, its clinical significance is suspected. Thus, hard and soft tissue analysis should be considered in treatment planning.