Bi-maxillary Protrusion: An Orthodontic Management

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

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.

Objective: The purpose of this study was to evaluate the effects of four premolar extractions and orthodontic treatment on changes to the lips and vermilion height during a posed smile. Methods: Fifteen female patients who were diagnosed with bimaxillary protrusion and treated with four premolar extractions were selected. The control group consisted of 25 female volunteers with a normal occlusion. Frontal photographs of the patients during a posed smile were taken before and after orthodontic treatment. Thirty-five landmarks on the upper and lower lips were identified and used to generate measurements of lip area and vermilion height. Linear and angular cephalometric measurements were also obtained. Results: The mean values for vermilion height and lip form before orthodontic treatment were significantly larger in the treatment group compared with those of the control group. Following treatment, values significantly decreased to the extent that there was no significant difference in the vermilion height and lip form between the post-treatment and control groups. Only three and four significant correlations were found between the changes in incisor position and changes in vermilion height and lip area for the upper and lower lips, respectively. Conclusions: The vermilion height and lip area in patients with bimaxillary protrusion approached comparative and normal values as a result of four premolar extractions and orthodontic retraction.

Bimaxillary protrusion is a commonly seen deformity in Asian populations. This condition is characterized by protrusive and proclined upper and lower incisors and an increased procumbency of the lips. It is usually combined with lip incompetence, gummy smile, mentalis strain, and anterior open bite. Facial aesthetics is the primary concern of these patients. Successful treatment depends on a thorough evaluation and understanding of this dentofacial deformity. Typical orthodontic treatment includes retraction and retroclination of maxillary and mandibular incisors after extraction of the four first premolars. Orthognathic surgery is required to correct significant skeletal problems. Anterior subapical osteotomies and extraction of premolars can correct sagittal excess of the jaw bones and relieve dental crowding. Segmental maxillary osteotomies are performed to treat patients with an associated exaggerated curve of Spee and vertical maxillary excess. Differential intrusion of anterior and posterior maxilla/maxillary segments with clockwise rotation of the occlusal plane is a useful technique for treatment of anterior open bite and creation of a consonant smile arc. Le Fort I osteotomy with setback sometimes provides an alternative to segmental maxillary osteotomies. Meticulous planning and execution of osteotomies in accordance with surgical planning are essential for aesthetic and functional outcome.

BackgroundThis study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment.MethodsThis retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson’s correlation test (alpha = 0.05).ResultsA significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P < 0.001), which was correlated with the magnitude of retraction of upper and lower incisors (r = 0.6 − 0.8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0.001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0.001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r = 0.4 − 0.6).ConclusionAccording to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions.

Thirty-two adult oriental patients aged 18-26 years who sought treatment for their bimaxillary protrusion were treated with the Begg appliance following extraction of four first premolars. A cephalometric study was undertaken to determine the soft tissue changes in lip profile following treatment. Results show that the upper incisors were retracted by 5.6 mm +/- 0.8 mm and the lower incisors by 4.4 +/- 0.8 mm on the average. The nasolabial angle became more obtuse increasing from 80.7 degrees to 90.7 degrees. The upper lip and lower lip lengthened by 1.9 mm and 1.2 mm, respectively. The lower lip to 'E' line reduced from 7.5 mm to 3.7 mm. All the previous changes were statistically significant (p less than 0.01). The upper lip to upper incisor retraction was 1:2.2 while the lower lip to lower incisor retraction was 1:1.4. The correlation coefficients (r) were 0.72 (p less than 0.01) and 0.80 (p less than 0.01), respectively. The changes in the cants of mandibular and occlusal planes were statistically insignificant. This study shows that the Begg appliance has the ability to significantly reduce bimaxillary protrusions and thereby improve facial aesthetics.

Mandibular incisor crowding is the most frequently occurring characteristic of malocclusion, which can be resolved by removing single lower incisor. The aim of this study was to evaluate and compare the pre- and post-treatment outcomes through model and cephalometric analysis of the patients subjected to single lower incisor extraction. In this retrospective study pre- and post-treatment lateral cephalograms and models of 23 patients who underwent fixed orthodontic treatment with single incisor extraction on lower arch were evaluated. The study subjects were classified into two groups based on extraction pattern (Group I: Upper premolar and lower single incisor extraction; Group II: Upper non extraction and lower single incisor extraction). Both cephalometric and model analysis were carried out using Ilexis FACAD AB-2014 Version3.8.0.0 (Ilexis AB, Sweden). Wilcoxon Signed Rank test was used to compare the pre and post-treatment quantitative parameters. A significant decrease was observed in the maxillary intermolar width, mandibular intercanine width, mandibular intermolar width, mandibular arch length and anterior Bolton’s ratio. Group I subjects revealed a greater decrease in maxillary intermolar width compared to Group II, whereas a greater decrease in mandibular intercanine width, mandibular intermolar width and anterior Bolton’s ratio was documented in Group II subjects compared to Group I. Cephalometric analysis revealed significant proclination and extrusion effect of lower incisors along with protrusive tendency of the lower lip. The findings of the present study provide an additional option of extracting single lower incisor, in borderline or Class II camouflage treatment cases.

To compare the efficacy of traditional occlusal guides with computer-aided surgical simulation (CASS) guides in enhancing postoperative outcomes for patients with bimaxillary protrusion. This retrospective study evaluated 34 patients undergoing anterior maxillary and mandibular subapical osteotomy at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences. Fourteen patients were treated using traditional occlusal guides, whereas 20 patients were treated with CASS guides (median age 28.6 years, median follow-up 259 days). Pre and postoperative cephalometric indicators were measured using cephalometric software. Data analysis was conducted using SPSS 14.0, with significant differences determined at P < 0.05. All 34 patients experienced primary healing without complications. Follow-up indicated significant improvements in key cephalometric measurements in the CASS group compared with the traditional group, including mandibular position (SNB angle, P < 0.001), jaw relationship (ANB angle, P < 0.001), facial angle (FH-NPo, P = 0.002), and condyle-to-sella distance (Co-S, P = 0.024). The CASS group also showed better aesthetic outcomes, with significant reductions in overjet ( P = 0.012), overbite ( P = 0.001), and improved alignment of upper and lower incisors (U1-L1 angle, P = 0.031). CASS-guided surgery offers a superior alternative to traditional methods for treating bimaxillary protrusion, providing more precise and aesthetically pleasing results. This study highlights the significant advantages of using advanced digital simulation and 3-dimensional printing technologies in orthognathic surgery.

Purpose The objective of this study was to assess the importance of orthodontic extractions in the setting of facial harmony to adolescents with bimaxillary protrusion. Material and methods: The orthodontic files of 73 adolescents with incisors protrusion treated with or without premolar extractions were studied on pre- and post-treatment facial photographs in a retrospective cohort study, while dental casts of 69 were assessed. The best-fit template of normal proportions was superimposed to the photograph and the facial harmony scores were obtained, while the DAI (dental aesthetic index) was studied in the models. Intra- and intergroup statistical comparisons and the index of improvement were determined. Results: The groups demonstrated significant change of lips positioning, though extraction group reached relative higher index of improvement. There was significant improvement in the labiomental groove position only for the extraction group in a profile view. Generally, a high success rate of dental relationships was found in the DAI. Conclusions: Both treatment protocols reached significant improvement of facial harmony. Orthodontic extractions of premolars might be related to establishing normal occlusion in cases with bimaxillary protrusion, while preventing worse hyperactive mental muscle when the arch discrepancy is negative. Abbreviations: 1-NA: Upper incisors cephalometric protrusion in millimetres; 1-NB: Lower incisors cephalometric protrusion in millimetres; AIR: Alare at right side; Al: Alare; AlL: Alare at left side; Ch: Cheillion; ChL: Cheillion at left side; ChR: Cheillion at right side; DAI: Dental Aesthetic Index; Ex: Exocanthion, posterior contour of the Orbitale; G: Glabela; Li: Inferior Lip; Ls: Superior Lip; Me: Menton; Msw: Midpoint of the craniofacial depth; OA: Anterior contour of the Orbitale; Ocp: Occipital; OL: Lower contour of the Orbitale; OU: Upper contour of the Orbitale; PLL: Pupil at left side; PLR: Pupil at right side; Pog: Pogonion; Sm: Labio-mental sulcus; Sn: Subnasale; Tr: Trichion; V: Vertex; ZyL: Zygion at left side; ZyR: Zygion at right side

Background: Bimaxillary protrusion is a common malocclusion that can lead to functional and aesthetic issues. Conventional orthodontic treatment may not always be effective, and surgical approaches can be invasive. The Periodontally Accelerated Osteogenic Orthodontics (PAOO) technique is a minimally invasive alternative that involves corticotomy and orthodontic treatment. Objective: This case report aimed to evaluate the effectiveness of the PAOO technique for the correction of bimaxillary protrusion in a 16-year-old female patient. Methods: The PAOO technique involved corticotomy and piezocision on a 16-year-old female patient undergoing orthodontic treatment with a fixed appliance. The patient was being followed up for 18 months after orthodontic appliance placement with premolars extractions but did not get any favorable result and was referred by the Department of Orthodontics to undergo corticotomy procedure. The effectiveness of the treatment was evaluated using cephalometric and occlusal analyses. Results: The PAOO technique significantly improved the patient’s skeletal and dental parameters. The maxillary and mandibular incisors were retracted, resulting in a significant improvement in the patient’s profile. The occlusal analysis showed good intercuspation and a stable occlusion. Conclusion: The PAOO technique is a viable option for the correction of bimaxillary protrusion, as it can achieve significant improvements in skeletal and dental parameters with minimal invasiveness. Further studies are needed to validate these findings and compare the PAOO technique with conventional surgical and orthodontic approaches.

Increased upper lip procumbency is associated with protrusive maxillary dentition in Angle’s class I malocclusion, creating unaesthetic facial profile, leading to the need of orthodontic treatment where Enmasse retraction will require maximum anchorage.The present study was conducted to compare Enmasse retraction of maxillary anteriors using mini implant and conventional anchorage in Angle’s Class I malocclusion with bimaxillary protrusion. A numeric approach was adopted. Finite element method was used to determine the stress and displacement of various components at a given time by dividing it into two groups namely, Implant arrangement and T- loop arrangement for enmasse retraction. Significant differences were observed when the stress values were compared between Implant arrangement and T-loop arrangement. In Implant arrangement highest stress values were seen around the lateral incisors and in T loop arrangement stresses were found around canine and premolar. Comparison of displacement in both arrangements gave results of greater displacement in anterior and posterior segments in T-loop arrangement. Mini implants were considered more effective for enmasse retraction but in this study, it was found that although the rate of retraction/ displacement was more in T-loop arrangement but Mini implants in implant arrangement served as an absolute anchorage.

Clear aligner therapy (CAT) has become a popular choice among patients seeking orthodontic treatment. However, CAT is not optimal for certain types of tooth movements. This case report illustrates a hybrid approach combining CAT with power arms to achieve controlled space closure after lower incisor extraction. A fit and healthy man presented with a Class 1 malocclusion on a Class 1 skeletal base with bimaxillary protrusion, slightly increased vertical proportions, and mild crowding in the upper and lower arches. He was concerned about his 'irregular lower front teeth and inability to clean them'. Lower incisor extraction treated with clear aligner therapy (CAT). The patient's malocclusion was successfully treated with CAT and the extraction of a lower incisor, achieving satisfactory root parallelism for the teeth adjacent to the extraction space. The patient reported satisfaction with the treatment results. Power arms can be considered a useful adjunct to CAT for minimising unwanted tipping in lower incisor extraction cases. Further research on more complex cases and a larger sample size is warranted to validate the findings of this case report and explore long-term stability.

In the present report, two techniques of space closure; two-step anterior teeth retraction (TSR) and en masse retraction (ER) were used in two adult patients who had bimaxillary protrusion and were treated with four premolar extractions and fixed orthodontic appliance therapy. Both patients had a Class I dental malocclusion and the same chief complaint, which is protrusive lips. Anterior teeth were retracted by two-step retraction; canine sliding followed by retraction of incisors with T-loop archwire in the first patient and by en masse retraction using Beta titanium alloy T-loop archwire in the second case. At the end of treatment, good balance and harmony of lips was achieved with maintenance of Class I relationships. The outcome of treatment was similar in the two patients with similar anchorage control. ER can be an acceptable alternative to the TSR during space closure since it is esthetically more acceptable. However, it requires accurate bending and positioning of the T-loop.

A 13-year-old female with a chief complaint of continuing treatment presented with Class I skeletal pattern and slight facial asymmetry. Intraorally, she had Class II molar relationship on the right side, class l on the left side and 3mm. of midline discrepancy. Her upper and lower incisors were proclined and slightly crowded. She had 1 mm. overbite and 5mm. overjet in initial mounted casts. Splint therapy was suggested to stabilize mandibular position. After splint wear, a new mounting was made, which resulted in an open bite from left second molars to right second molars. A visual treatment objective was prepared with four first bicuspid extractions. After 9 months, upper second molars were extracted and temporary anchorage devices (TADs) were placed in the upper arch for intrusion. Detailing strategies such as bracket repositioning, occlusal adjustment, and elastics were used. The role of segmented models, second molar extraction treatment, and superimposition analysis in patients with discrepancies in mandibular position is discussed. It is concluded that a thorough case workup is needed to provide patients with a successful treatment for open bite cases. This case was treated orthodontically in 2 years with four bicuspid and upper second molar extractions as well as vertical control with TADs.

Objective To invesigate the therapeutic effect of anterior subapical osteotomy combined with postoperative orthodontic treatment for bimaxillary protrusion based on surgery-first approach(SFA). Methods From April 2015 to April 2016, 22 adult patients with bimaxillary protrusion were treated with bimaxillary anterior subapical osteotomy without peroperative orthodontic treatment. Digital computer-aided technology was used for preoperative design and dental model simulation surgery. Then the occlusal guide plate was made for intraoperative built-up of temporary occlusion. Two weeks after orthognathic surgery, a short-term orthodontic treatment was carried out to improve the occlusion. Cephalometric analysis was done to evaluate the treatment effects. 19 cephalometric parameters about hard and soft tissues were measured and compared in all cases before and after SFA combined treatments. All data were statistically analyzed by SPSS software package. Results Primary healing was achieved in all the 22 cases without any infection or necrosis of bone and dental pulp. During the follow-up period of 6-12 months, all the patients were satisfied with the profile contour. The cephalometric parameters of hard and soft tissues changed remarkably. U1E-McN and L1E-McN set back (-10.5±4.9) mm and (-8.0± 6.9) mm respectively. Upper and lower lip set back obviously. SNA decreased from (82.5±2.8) to (77.9±2.3) degrees on average. SNB decreased from (79.1±5.4) to (74.6±3.8) degrees on average. Upper and lower lip protrusion decreased obviously. TUL-E line decreased from the mean value of (2.7±2.7) mm to (0.5±3.2) mm and TLL-E line from (5.2±4.0) mm to (1.4±2.7) mm. The aesthetic contours were remarkably improved. Conclusions Anterior subapical osteotomy combined with postoperative orthodontic treatment based on SFA could correct adult bimaxillary protrusion effectively with normal occlusion, satisfactory soft tissue aesthetic profile. Key words: Subapical osteotomy; Surgical orthodontics; Bimaxillary protrusion; Cephalometric analysis