A clinical approach to managing open-bite malocclusion associated with severe crowding.

Open bite has been identified as one of the most challenging malocclusions in orthodontics. The treatment approach is complex, the resulting esthetics may not meet the patient's expectations, and the chance of recurrence is high. A 13-year-old girl presented a skeletal Class II malocclusion associated with anterior and posterior open bite, maxillary transverse deficiency, severe anterior crowding, and a hyperdivergent facial pattern. Orthodontic treatment was performed with a Haas expander and subsequent standard edgewise appliances, and the 4 first premolars were extracted. The vertical control of facial growth was undertaken with vertical pull chincap therapy, mini-implants associated with a titanium-molybdenum alloy cantilever on the right and left buccal sides, and a stainless steel alloy transpalatal arch. Posttreatment records showed a bilateral Class I molar relationship, ideal overbite and overjet, and improved facial profile and gingival health. The cephalometric analysis revealed a good balance of the skeletal pattern and facial profile, with an appropriate inclination of the maxillary and mandibular incisors. After a 7-year retention period, the outcome was pleasant facial esthetics and smile and stability of the dental occlusion. This case shows that the clinical approach was adequate, with treatment outcomes achieving positive aspects of function, esthetics, and stability.

Skeletal and alveolar changes in conventional rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE): a prospective randomized clinical trial using low-dose CBCT.

BACKGROUND: This prospective randomized clinical trial aimed to evaluate the immediate and short-term skeletal, dentoalveolar, and periodontal effects of rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE) in adolescent and young adult patients. METHODS: This study followed a two-arm, parallel, randomized clinical trial design that recruited patients with transverse maxillary deficiency in a 1:1 allocation ratio. Forty patients (14 men and 26 women) requiring maxillary expansion were randomly allocated to the RPE (n = 20, age = 14.0 ± 4.5) or MARPE (n = 20, age = 14.1 ± 4.2) groups. The assignment was performed via computer-generated block randomization, with a block size of four. Upon identical (35 turns) amount of expansion, low-dose cone-beam computed tomography images were taken before treatment (T0), immediately after expansion (T1), and after a 3-month consolidation period (T2). The primary outcome of this study comprised the assessment of midpalatal suture separation. Secondary outcomes included, skeletal, dentoalveolar, and periodontal measurements, which were performed at each time point. RESULTS: The frequency of midpalatal suture separation was 90% (18/20) and 95% (19/20) for the RPE and MARPE groups, respectively. A greater increase in nasal width in the molar region (M-NW) and greater palatine foramen (GPF) was observed immediately after the expansion (T1-T0) and consolidation periods (T2-T0) in the MARPE group compared to the RPE group (P < 0.05). The MARPE and RPE groups showed similar dentoalveolar changes except for the maxillary width (PM-MW, M-MW). The MARPE group presented greater bilateral first premolar (PM-MW) and molar (M-MW) maxillary width in relation to the RPE group (P < 0.05). Through the expansion and consolidation periods (T2-T0), lesser buccal displacement of the anchor teeth was observed in the MARPE group (PM-BBPT, PM-PBPT, M-BBPT [mesial and distal roots], and M-PBPT)( P < 0.05). CONCLUSIONS: Midpalatal suture separation was observed in 90% and 95% of patients in the RPE and MARPE groups, respectively. Both RPE and MARPE groups exhibited significant triangular basal bone expansion and skeletal relapse during consolidation. Under identical amounts of expansion, the MARPE group showed lower decrease in the skeletal, dentoalveolar and periodontal variables after consolidation. The reinforcement of RPE with miniscrews contributes to the maintenance of the basal bone during consolidation period. Trial registration WHO Institutional Clinical Trials Registry Platform (IRB No. KCT0006871 / Registration date 27/12/2021).

Mandibular buccal shelf and infrazygomatic crest thicknesses in patients with different vertical facial heights.

INTRODUCTION: The purpose of this study was to use cone-beam computed tomography (CBCT) to determine bone thickness in the mandibular buccal shelf (MBS) and the infrazygomatic crest (IC) in individuals with different vertical facial heights for ultimate placement of miniscrews. METHODS: The sample consisted of 100 individuals aged at least 16 years, of whom 58 were women, and 42 were men. The mean age was 19.18 years (± 5.5 standard deviation). The patients' facial height was determined by the gonial angle. Cross-sectional slices of the MBS and IC were obtained with CBCT to evaluate bone thickness for the insertion of miniscrews in these extra-alveolar sites. Spearman's nonparametric test was used to correlate the gonial angle with MBS and IC thickness. The level of significance was 5%. RESULTS: The gonial angle ranged from 102.4° to 143.2°. Bone thickness in the MBS increased posteriorly, whereas bone thickness in the IC decreased posteriorly. There was an inversely proportional correlation between the gonial angle and the MBS. There was no correlation between the IC and the gonial angle. CONCLUSIONS: Short-faced individuals had higher bone thickness values in the MBS than long-faced ones. There was no correlation between the patients' vertical face height and the bone width in the IC. The best site to install miniscrews in the MBS is buccal to the second molar distal root, whereas in the IC, it is buccal to the first molar mesiobuccal root. CBCT may be necessary to install extra-alveolar miniscrews correctly, especially in the IC.

Influence of bone architecture on the primary stability of different mini-implant designs.

INTRODUCTION: Mechanical interlocking between a mini-implant (MI) and the bone substrate reflects directly on the primary stability achieved. The purposes of this study were to evaluate MI design performance in distinct bone substrates and correlate geometric characteristics with insertion site quality. METHODS: Two types of self-drilling MIs (1.6 × 8 mm) were allocated to 2 groups according to their geometric designs: Tomas system (Dentaurum, Ispringen, Germany) and Dual-Top (Rocky Mountain Orthodontics, Denver, Colo). Forty sections (8 × 10 mm) were taken from bovine pelvic ilium and pubic bone. Geometric design characteristics were evaluated using scanning electron microscope imaging and Image-Pro Insight software (Media Cybernetics, Rockville, Md). Bone quality parameters were assessed with a microcomputed tomography system, and primary stability was evaluated by insertion torque and pull-out strength. Intergroup comparisons were performed with analysis of variance and Tukey tests, and the Pearson correlation test was carried out (P <0.05). RESULTS: No significant difference was observed in the comparisons of the groups (Tomas: insertion torque, 12.87 N·cm; pull-out strength, 181 N; and Dual-Top: insertion torque, 9.95 N·cm; pull-out strength, 172.5 N) in the ilium. However, the Tomas group had a marked increase in insertion torque (25.08 N·cm; P <0.05) in the pubic bone. CONCLUSIONS: MI mechanical performance differed according to bone quality parameters, indicating that certain geometric parameters may be set depending on the insertion substrate.

Immediate changes in condylar position after rapid maxillary expansion.

INTRODUCTION: Although the dentoalveolar and skeletal effects of rapid maxillary expansion are well documented, the condylar response to this procedure is not well understood. The purpose of this study was to test the following null hypothesis: rapid maxillary expansion promotes immediate changes of the position of the condyles in patients with Class I malocclusion. METHODS: Thirty-four subjects with Class I malocclusion underwent rapid maxillary expansion. Cone-beam computed tomography images were collected before activation of the expander and 3 weeks later, after screw stabilization. Using specific software functions, it was possible to determine and reproduce head positioning and landmarks during the different times of the study. RESULTS: The axial, coronal, and sagittal planes were examined, and no asymmetries in condylar positions were found at either time. However, statistically significant anterior and inferior displacements of these structures occurred, with respective average values of 0.52 and 0.49 mm. Lateral inclinations of both condyles were observed and confirmed by the coronal condylar angles. CONCLUSIONS: The null hypothesis was rejected. Statistically significant anterior and inferior displacements of the condyles occurred. Lateral inclination of the condyles was observed.

Colonization of Streptococcus mutans on esthetic brackets: self-ligating vs conventional.

INTRODUCTION: Self-ligating orthodontic brackets rely on clips, rather than ligatures, to hold the archwire in place. It is unknown whether replacing ligatures with clips affects the adherence of Streptococcus mutans. The aim of this research was to evaluate whether self-ligating brackets have an advantage over conventional brackets as determined by the adherence of S mutans. METHODS: The sample consisted of 50 esthetic brackets, divided into 3 experimental groups and 2 control groups of 10 brackets each. Two experimental groups were active self-ligating brackets (QuicKlear; Forestadent, Pforzheim, Germany; and In-Ovation C; Dentsply GAC, Bohemia, NY); the other was a passive self-ligating bracket (Damon 3; Ormco, Glendora, Calif). The 2 control groups were conventional brackets (Mystique; Dentsply GAC; and Clarity; 3M Unitek, Monrovia, Calif). The brackets were randomly bonded to the canines, first and second premolars, and first and second molars in the mandibular left hemiarch of 10 male participants. Biofilm was collected from the tooth surfaces before bonding and from the brackets on day 21 and placed in Petri dishes containing Mitis salivarius agar. The brackets were removed on day 28 and examined by using scanning electron microscopy. Statistical analysis, analysis of variance, and the Tukey correction with a P value of 0.05 were used. RESULTS: The greatest numbers of colonies were found in an active self-ligating bracket group (In-Ovation C), and the fewest colonies were in a conventional bracket group (Clarity). The largest colonies formed on active self-ligating brackets. In the slot, the greatest formation was in a control group (Mystique). CONCLUSIONS: Self-ligating esthetic brackets do not promote greater or lesser S mutans colonization when compared with conventional brackets. Differences were found to be related to the material composition of the bracket.

Influence of the maxillary dimensions and anterior teeth anatomy on the buccal impaction of upper permanent canines: A three-dimensional case-control study.

OBJECTIVE: The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate the association of the buccal impaction of upper permanent canines with their dimensions and the maxilla bone base. MATERIAL AND METHODS: Cone beam computed tomography files of 66 patients were allocated into: impaction group (ICG/n=33/mean age 15.7±3.9 years), with 44 impacted canines by the buccal side; control group (CG/n=33/mean age 15.66±3.99 years), matched for age and sex, with 66 canines normally erupted. The following measurements were obtained from ICG and CG groups: linear and volumetric canine dimensions, linear measurements of upper permanent central and lateral incisors, measurements of the anterior perimeter and transverse segments of the maxilla. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni (α=0,005). RESULTS: Higher values were found in the means of the variables regarding to the anterior teeth crowns in the ICG group, however, without a significant difference (P<0,005). The upper arch anterior perimeter of the individuals with canine impaction through buccal area was reduced compared to CG (P=0.001). CONCLUSIONS: It can be concluded that individuals with upper buccal impacted permanent canine showed a significantly smaller anterior perimeter of the maxillary arch when compared to the control group. Although greater canine mesiodistal diameter was found in this group, there is no statistical association with the occurrence of this condition.

Response of masticatory muscles to treatment with orthodontic aligners: a preliminary prospective longitudinal study.

INTRODUCTION: The emergence of orthodontic aligners has provided an aesthetic and comfortable option for orthodontic treatment. However, the encapsulated design of the aligners can influence the masticatory muscles, and might compromise safe treatment. OBJECTIVE: This preliminary longitudinal study aimed to investigate whether the use of orthodontic aligners affects the biting force and myoelectric activity of the superficial masseter and anterior temporal muscles. METHODS: Ten subjects participated in the study and underwent treatment during an 8-month follow-up period. The root mean square (RMS), the median power frequency (MPF) of the surface electromyography (sEMG) signals, and the biting force (kgf) were recorded and normalized relative to the pretreatment condition. The data were analyzed by repeated-measure analysis of variance (ANOVA), with the significance level set at 5%. RESULTS: Both the superficial masseter and the anterior temporal muscles presented an increase in sEMG signal activity during the treatment, with a marked increase in the latter compared to the former (p<0.05). Moreover, a significant decrease in bite force was evidenced (p<0.05). CONCLUSIONS: This preliminary study observed that the orthodontic aligners affected the muscle recruitment pattern of masticatory muscles, and reduced biting performance during the 8-month follow-up period.

Influence of the maxillary dimensions and lateral incisor anatomy on the palatal impaction of maxillary permanent canines: A three-dimensional case-control study.

OBJECTIVE: The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate associations between the upper permanent canines palatal impaction, lateral incisors morphology and the maxilla bone base. MATERIAL AND METHODS: Cone-beam tomography files from 62 subjects were divided into 2 groups: impaction group (ICG/n=31; mean age 14.3±2.4) with 45 canines impacted on the palatal side and age- and sex-matched control group (CG/n=31; mean age 14.3±2.3), with 62 normally erupted canines. Linear and volumetric measurements of the lateral incisors, linear transversal measures and the maxillary anterior perimeter were taken. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni. RESULTS: Significant differences were found for crown length and root diameter (buccal-palatal) (P<0.005). The maxillary anterior perimeter in the ICG was reduced in relation to the GC but not significantly (P=0.008). The transverse skeletal variables of the maxilla were equivalent in the intergroup comparison (P>0.005). CONCLUSION: Smaller dimensions in the crown length and in the upper permanent lateral incisors root buccal-palatal diameter were associated with the impaction of upper permanent canines on the palatal side. The maxillary transverse morphology did not show any association with the occurrence of this condition.

Three-dimensional micromorphology of human midpalatal suture and pterygomaxillary articular complex.

BACKGROUND: Sutures exist in the craniofacial area, and the pattern of maturation and synostosis of facial sutures is largely unknown. METHODS: For a comprehensive understanding of the three-dimensional circummaxillary suture micromorphology, human midpalatal suture (MPS) and pterygomaxillary articular complex from eight subjects' (five males, three females, 72-88 years old) autopsies were longitudinally scanned with microcomputed tomography. Additional histology was performed for hematoxylin and eosin staining. Sutural micromorphology was assessed by interdigitation index (II), obliteration index (OI) and obliteration number. Intergroup comparisons were performed with Kruskal-Wallis and Mann-Whitney U with Bonferroni correction (α = 0.005). Correlation with anteroposterior and craniocaudal gradients was assessed with Spearman's correlation test (α = 0.05). RESULTS: Maxillary region of MPS presented a higher II 1.50 (0.61) and obliteration number per slice 8 (9) (P < 0.005). OI was increased in palatomaxillary 35% (47%) followed by pterygopalatine suture 25% (49%) (P < 0.005). The II and OI of the MPS exhibited only a weak anteroposterior gradient, with relatively low correlations. Obliteration areas were found sporadically along the entire MPS. CONCLUSIONS: Based on these findings, it is conceivable that the success of nonsurgical maxillary expansion largely depends on individual variations in sutural morphology and maturation rather than appliance design.

Surgical prediction of skeletal and soft tissue changes in Class III treatment.

PURPOSE: The purpose of this study was to study the treatment outcomes and accuracy of the digital prediction using Dolphin Imaging Software and the actual postoperative outcome in subjects presenting Class III malocclusions. MATERIALS AND METHODS: Maxillary advancement surgery was performed in group 1, and maxillary advancement was combined with mandibular setback surgery in group 2. Predictive cephalometric tracings were made using Dolphin Imaging Software. RESULTS: Before surgery, the maxillary deficiency was significantly greater in group 1 than in group 2, and the mandibular length was significantly greater in group 2. Surgical reductions in mandibular length and angle were significantly greater 12 months after surgery than indicated by the predictive cephalometric tracings. CONCLUSION: In groups 1 and 2, maxillary advancement surgery was performed in accordance with the Dolphin Imaging Software. The mandibular setback surgery performed was beyond the established plan, but without clinical implications. Mandibular dentoskeletal measurements showed a greater correlation with the profile than the maxillary measurements.

Miniscrew covering: an alternative to prevent traumatic lesions.

During orthodontic treatment with miniscrews, complications such as aphthous ulceration, soft-tissue coverage of the miniscrew head, soft-tissue inflammation, infection, and peri-implantitis can occur. Good hygiene can prevent inflammation by infection but does not prevent traumatic oral mucosal lesions at the buccal mucosa. The purpose of this article was to describe the use of a physical barrier--a light-cured temporary filling material--to cover the miniscrew head and prevent soft-tissue trauma.

The importance of the diagnostic setup in the orthodontic treatment plan.

The aim of this study was to address the importance of the diagnostic setup by examining two cases where diagnostic setups were made in order to determine the treatment plan. The diagnostic setup is a fundamental aid and should be used when there are doubts in the orthodontic planning.

Characteristics of patients seeking orthodontic retreatment.

BACKGROUND: The aim of this cross-sectional study was to investigate patients' experiences with previous orthodontic treatment for those seeking retreatment, and their expectations and motivation for doing so. METHODS: A total of 72 patients were invited to answer an anonymous questionnaire. Of these, 36 (13 men and 23 women, mean age 26.3 ± 5.8 years) were seeking retreatment (study group), and 36 (13 men and 23 women, mean age 25.5 ± 6.8 years) were seeking treatment for the first time (control group). Casts from both groups were assessed with the index of complexity, outcome, and need (ICON) score, to objectively determine the treatment need and complexity. Student`s t test for independent samples, and paired Student`s t test, were performed for comparisons between the retreatment and control groups, and between retreatment and previous treatment, respectively. RESULTS: There was no statistically significant difference between retreatment patients` motivation for the previous treatment and motivation for the retreatment. However, the mean visual analog scale (VAS) scores for motivation differed significantly between the retreatment and control groups (73.8 ± 23.9 and 87.5 ± 14.5, respectively). The mean ICON score of the retreatment group was lower than that for the control group (25 ± 14 and 31 ± 16, respectively). CONCLUSIONS: Patients seeking retreatment were less motivated for treatment, and tooth irregularity was the chief reason for seeking treatment in both groups. Although an objective treatment need was not observed in the 2 groups, all of them had some occlusal traits that clinically justified the orthodontic treatment.

Assessment of mini-implant displacement using cone beam computed tomography.

OBJECTIVES: To assess, through cone beam computed tomography (CBCT), the mini-implants' stability and behaviour when submitted to orthodontic force during upper molars' intrusion. MATERIAL AND METHODS: Forty-one mini-implants were divided into two groups: 30 in the buccal and palatal mini-implants group (BPMI), inserted into buccal and palatal sides, and 11 in the midpalatal mini-implants group (MPMI), inserted into midpalatal suture. One day after insertion, a 200 gf was applied on the mini-implants during a 5-month period. CBCT was performed twice: before force application (CBCT 1) and 5 months later (CBCT 2). For mini-implant displacement assessment, the distance of mini-implants' head (HMI) and tail (TMI) to coronal, sagittal and axial planes was measured at CBCT 1 and 2. RESULTS: For the BPMI group, the displacement rate was statistically significant (P<0.05) in all three dimensions for both the head and the tail. For the MPMI group, the displacement rate was statistically significant (P<0.05) only in the antero-posterior (head and tail) and vertical (head) dimensions. CONCLUSIONS: Buccal, palatal and midpalatal mini-implants showed some displacement (mean value ≤0.78) when submitted to force, although they are aimed to provide stable skeletal anchorage.

Reasons influencing the preferences of prospective patients and orthodontists for different orthodontic appliances.

OBJECTIVE: To evaluate the reasons influencing the preferences for a certain type of orthodontic appliance over another among prospective patients (PP) and orthodontists. METHODS: A total of 49 PP and 51 orthodontists were asked about their preferences for the following appliances: clear aligners (CA), lingual metallic brackets (LMB), polycrystalline and monocrystalline ceramic brackets, and buccal metallic brackets (BMB). The participants rated the importance of 17 potential reasons that would explain their choices. The reasons that contributed most to these preferences were identified. Non-parametric tests (Fisher's exact, χ2 and Mann-Whitney tests) and multivariate analyses (regression and discriminant analysis) were used to assess the data (α = 0.05). RESULTS: CA and BMB were the most chosen appliances by PP and orthodontists, respectively. LMB was the most rejected option among both groups of participants (p < 0.001). Rates of the importance of pain/discomfort, smile esthetics, finishing details, and feeding/speech impairment showed the highest differences between PP and orthodontists (p < 0.0005). Discriminant analyses showed that individuals who considered treatment time and smile esthetics as more important were more likely to prefer CA, while those who prioritized finishing details and cost were more likely to choose BMB (p < 0.05). CONCLUSIONS: Reasons related to comfort and quality of life during use were considered as more important by PP, while those related to the results and clinical performance of the appliances were considered as more relevant by orthodontists.

Dentofacial and skeletal pattern in African descendants from southeastern Brazil: clinical prospective study.

OBJECTIVE: The aim of this study was to evaluate characteristics of African-Brazilians young adults with excellent dental occlusion, including bimaxillary protrusion; compare them to European-American Caucasian standards, and determine whether there is sexual dimorphism in the display of this phenotype. METHODS: Lateral cephalometric radiographs were obtained from 43 African-Brazilians within military personnel (28 males and 15 females, average age 22.4 ± 3.4 years) with normal occlusion, selected from a group of 394 volunteers. Thirty-one angular and linear measurements were evaluated. Student's t-test for independent samples was used to compare results with those established by European-American standards, previously described in the literature. RESULTS: Considering the dentoalveolar pattern, seven angular and six linear measurements showed statistically significant differences (p< 0.001) when compared to Caucasian cephalometric standards. African-Brazilians' subjects showed lower cranial base angle (SNAr = 119.87 ± 5.66º) and anterior cranial base length (SN-distance = 68.63 ± 4.50 mm) (p< 0.001). The maxilla (SNA = 88.51 ± 3.23º) and the mandible (SNB = 85.06 ± 3.24º) were protruded in relation to the SN line (p< 0.001). Sexual dimorphism was significant for L1.NB (degrees) (p< 0.01), and interincisal angle (U1.L1) (p< 0.05). CONCLUSION: African-Brazilian young adults presented differences regarding dental and craniofacial characteristics, when compared to European-American norms. It can be stated that Caucasian cephalometric norms should not be applied to African-Brazilian faces.

Anatomic variability in alveolar sites for skeletal anchorage.

INTRODUCTION: Because alveolar bone is used for skeletal anchorage, the variability and reliability of its dimensions are important. METHODS: Interradicular distances, cortical thicknesses, and buccolingual spaces were measured on computed tomography images of 22 adults (13 maxillary and 9 mandibular). Intra-arch analyses were done with paired t tests; the interarch comparisons were studied with independent t tests. The intraclass correlation coefficient was calculated between corresponding units. RESULTS: Interradicular distances were greater for the molars than for the incisors, and apical distances were greater than cervical. The mandibular lingual cortical thickness was the greatest, and the maxillary buccal cortical thickness was less than the mandibular in the molar apical zones. The widest and narrowest buccolingual spaces were found at the maxillary molars and the mandibular incisors, respectively. The cross values of cortical bone thickness were wider than the axial means and they had low agreement, so they had interradicular distances on the right and left sides. CONCLUSIONS: Although interradicular distances must be carefully assessed, the molars were favorable sites for skeletal anchorage. Placing anchorage in anterior sites requires even more careful planning, including the use of computed tomography records.

Influence of orthodontic loading on biomarkers levels around miniscrews.

OBJECTIVE: The aim of this study was to evaluate the levels of Interleukin-1α (IL-1α), Interleukin-1ß (IL-1ß), Interleukin-1 receptor antagonist (IL-1Ra), Interleukin-10 (IL-10), Interleukin-13 (IL-13), Vascular endothelial growth factor (VEGF), Granulocyte-colony stimulating factor (G-CSF), and Growth related oncogene (GRO) in the peri-miniscrew implant crevicular fluid (MICF) under orthodontic loading. DESIGN: The study sample comprised 14 miniscrews immediately loaded and 17 unloaded ones. A load of 200gF was immediately applied to the miniscrews in the loaded group after the placement surgery. Peri-miniscrew implant crevicular fluid was collected at baseline, at day 7, and at day 21. The levels of the biomarkers were measured using a multiplexed bead immunoassay. Intergroup comparisons were made using Mann-Whitney test. Friedman and Dunn's multiple comparison tests were used to evaluate intragroup differences over time. RESULTS: Although no statistical differences were observed between the groups at any time point for any of the 8 biomarkers evaluated, there was a statistically significant increase (p < 0.02) in the levels of all the biomarkers over time on both groups. CONCLUSIONS: An immediate loading of 200gF does not alter the balance in the inflammatory response in peri-miniscrew tissues.