Image fusion-based low-dose CBCT enhancement method for visualizing miniscrew insertion in the infrazygomatic crest.

Digital dental technology covers oral cone-beam computed tomography (CBCT) image processing and low-dose CBCT dental applications. A low-dose CBCT image enhancement method based on image fusion is proposed to address the need for subzygomatic small screw insertion. Specifically, firstly, a sharpening correction module is proposed, where the CBCT image is sharpened to compensate for the loss of details in the underexposed/over-exposed region. Secondly, a visibility restoration module based on type II fuzzy sets is designed, and a contrast enhancement module using curve transformation is designed. In addition to this, we propose a perceptual fusion module that fuses visibility and contrast of oral CBCT images. As a result, the problems of overexposure/underexposure, low visibility, and low contrast that occur in oral CBCT images can be effectively addressed with consistent interpretability. The proposed algorithm was analyzed in comparison experiments with a variety of algorithms, as well as ablation experiments. After analysis, compared with advanced enhancement algorithms, this algorithm achieved excellent results in low-dose CBCT enhancement and effective observation of subzygomatic small screw implantation. Compared with the best performing method, the evaluation metric is 0.07-2 higher on both datasets. The project can be found at: https://github.com/sunpeipei2024/low-dose-CBCT .

Efficacy of maxillary molar intrusion and quantification of related external apical root resorption - A comparison of two approaches.

OBJECTIVE: This retrospective single-centre study aimed to compare the efficacy of maxillary second molar intrusion with two different approaches, miniscrew-assisted molar intrusion and traditional segmental archwire intrusion, and to compare orthodontically induced external apical root resorption (OIERR) during intrusion between two groups via cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 40 adult patients (33.6 ± 10.3 years old) with supraerupted maxillary second molars due to the loss of antagonistic teeth were recruited, with 20 patients in each group. A segmental archwire with adjacent teeth as an anchorage was used in the control group, and 60-100 g of intrusive force was applied by using miniscrews in the experimental group to intrude the overerupted molars. Full-volume CBCT was performed before and after intrusion, and the amount of intrusion and extent of OIERR of the overerupted molars were compared between the two groups. RESULTS: Supraerupted maxillary second molars could be successfully intruded in an average of 5 months. There was more intrusive movement of the buccal and palatal cusps in the mininscrew group than that in the segmental archwire group (P < .05). The intrusive amount of palatal cusp was 3.67 ± 1.13 mm in the miniscrew group and 2.38 ± 0.74 mm in the segmental archwire group. More palatal OIERR was observed in the miniscrew group (30.3 ± 11.6 mm3) than in the segmental archwire group (21.0 ± 8.66 mm3) (P = .0063). There was no significant difference in OIERR between the two groups for mesial and distal buccal roots (P > .05). CONCLUSION: Miniscrews help effectively with supraerupted maxillary second molar intrusion, especially for palatal cusps. There was more OIERR in the palatal root when using miniscrews compared to the segmental archwire approach.

Is motor-driven insertion of orthodontic miniscrews more advantageous than manual insertion? A micro-CT evaluation of bone miniscrew contact surface area and cortical microcracks in rabbits.

AIM: This in vitro study aimed to evaluate and compare the bone-miniscrew contact surface area (BMC) and the cortical bone microcracks (CM) resulting from manual (hand-driven) and automated (motor-driven) orthodontic miniscrew (OM) insertion methods. METHODS: Thirty-three OM were inserted in the femurs of nine New Zealand rabbits using manual (n = 16) and automated (n = 17) insertions. After euthanizing the rabbits, bone blocks, each including one OM, were sawed. Micro-CT scanning was performed, and data analysis included reconstruction, binarization and quantification of morphometric parameters of BMC and the number and length of CM. Means and standard deviations for complete BMC, complete BMC proportion, cortical BMC, cortical BMC proportion, and length and number of CM were calculated. Mixed model analysis was used to adjust for more than one sample/CM per animal. A paired t-test was used to compare the number of CM between the two groups. RESULTS: Compared to the automated insertion, manually inserted miniscrews had significantly lower complete BMC (7.54 ± 1.80 mm2 vs. 11.99 ± 3.64 mm2), cortical BMC (5.91 ± 1.48 mm2 vs. 8.48 ± 1.90 mm2) and cortical BMC proportion (79.44 ± 5.84% vs. 87.94 ± 3.66%). However, it was not statistically significant in complete BMC proportion (p = .052). The automated insertion also resulted in a significantly lower mean number of CM than the manual method (p = .012). However, the length of the cracks was shorter in the manual group but with no significant difference (p = 0.256). CONCLUSION: Motor-driven OM insertion results in superior BMC and reduction in the number of CM, which may lead to better miniscrew stability.

Evaluation of stress and displacement of maxillary canine during the single canine retraction in the maxillary first premolar extraction cases- A finite element study.

OBJECTIVES: This finite element study aimed to simulate maxillary canine movement during anterior teeth retraction. MATERIALS AND METHODS: Three methods of maxillary canine movement including miniscrew sliding with high hooks (MSH), miniscrew sliding with low hooks (MSL), and the traditional sliding method (TS) without using miniscrews were simulated using three-dimensional finite element analysis. The initial displacement of the maxillary canine, the maximum principal stress of the periodontal ligament and the Von Mises stress were calculated. RESULTS: The distolingual tipping movements of the canine were shown in three movement modes. MSH showed a small tendency to lingual tipping movement and a extrusion movement while MSL had the largest lingual inclination. TS demonstrated a tendency toward distolingual torsion displacement. Compressive stress values were mainly concentrated in the range - 0.003 to -0.006 MPa. For tensile stress, the distribution of MSH and MSL was concentrated in the range 0.005 to 0.009 MPa, TS was mainly distributed about 0.003 MPa. Von Mises equivalent stress distribution showed no significant difference. CONCLUSIONS: The loss of tooth torque was inevitable, irrespective of which method was used to close the extraction space. However, miniscrew application and higher hooks reduced the loss of torque and avoided lingual rotation. CLINICAL RELEVANCE: This study shows that miniscrew implants with different hooks can better control the movement of the maxillary canines. The non-invasive nature of the finite element analysis and its good simulation of dental stress and instantaneous motion trend have a clinical advantage in the analysis of tooth movement.

Biomechanical analysis of miniscrew-assisted molar distalization with clear aligners: a three-dimensional finite element study.

BACKGROUND/OBJECTIVES: To compare the biomechanical characteristics of maxillary molar distalization with clear aligners in conjunction with three types of miniscrew anchorage. MATERIALS/METHODS: Three-dimensional (3D) finite element models of maxillary molar distalization with clear aligners and three types of miniscrew anchorage were established, including (A) control group, (B) direct buccal miniscrew anchorage group, (C) direct palatal miniscrew anchorage group, and (D) indirect buccal miniscrew anchorage group. The 3D displacement of maxillary teeth and the principal stress (maximum tensile and compressive stress) on the root and periodontal ligament (PDL) during molar distalization were recorded. RESULTS: The tooth displacement pattern during maxillary molar distalization in the four groups showed similarities, including labial tipping of anterior teeth, mesial and buccal tipping of premolars, and distal and buccal tipping of molars, but with varying magnitudes. Group C exhibited the greatest molar distalization, with the first molar achieving 0.1334 mm of crown distalization. Group D demonstrated a notable buccal crown movement (0.0682 mm) and intrusion (0.0316 mm) of the first premolar. Compared to Groups A and B, Groups C and D showed less labial crown tipping of the central incisor. Group B showed the greatest amount of maxillary incisor intrusion (central incisor: 0.0145 mm, lateral incisor: 0.0094 mm). Moreover, Groups C and D displayed significantly lower levels of compressive and tensile stress in the roots and PDL of the maxillary central and lateral incisors. LIMITATION: Molar distalization is a dynamic process involving sequential tooth movement stages; however, our research primarily examined the tooth movement patterns in the initial aligner. CONCLUSIONS/IMPLICATIONS: The use of miniscrew anchorage, especially direct palatal miniscrew anchorage, may enhance the treatment efficacy of maxillary molar distalization with clear aligners, leading to increased molar distalization, reduced mesial movement of premolars, and minimized labial tipping of anterior teeth.

Reliability and safety of miniscrew insertion planning with the use of lateral cephalograms assessed on corresponding cone-beam computer tomography images.

BACKGROUND/OBJECTIVES: Recently, lateral cephalograms have been proposed for guided miniscrew insertion planning. Therefore, the aim was to assess the reliability and safety of such planning on corresponding cone-beam computer tomography (CBCT) images. MATERIALS/METHODS: Intraoral scans, lateral cephalograms, and CBCT images of 52 subjects (even sexes distribution), aged 15.1 ±â€…2.5 years, were included. Miniscrew (n = 104) insertion planning was performed using lateral cephalograms superimposed on the maxillary intraoral scans, while the assessment of their bicortical placement, length in bone, contact with adjacent teeth, incisive canal, and nasal floor perforation was done on corresponding superimposed CBCT images. Moreover, maxillary incisor inclination, crowding, and the maxillary intercanine width were measured. RESULTS: The overall miniscrew length in bone was 7.2 ±â€…1.3mm. Bicortical placement was seen in 58.7% of the sample (38.5% of subjects). Incisive canal and nasal floor perforation was seen in 25% and 21.2% of subjects, respectively. No contact of the miniscrew with adjacent teeth was recorded. A negative significant interaction was seen between the miniscrew length in bone, the percentage of total miniscrew length and maxillary anterior teeth crowding (ß, -0.10, P = .047 and ß, -0.90, P = .006, respectively). Moreover, a positive significant interaction was seen between the incisive canal perforation and maxillary anterior teeth crowding (OR = 1.32, P = .021). LIMITATIONS: Exclusion of subjects with impacted teeth. CONCLUSIONS: Miniscrew insertion planning using lateral cephalograms, despite being safe in preventing contact with adjacent teeth, is limited in achieving bicortical placement and insufficient in completely avoiding incisive canal and nasal floor perforation.

Success rates of single-thread and double-thread orthodontic miniscrews in the maxillary arch.

AIM: There is limited research on the clinical performance of double-thread orthodontic miniscrews. This study aimed to compare the stability of double-thread and single-thread orthodontic miniscrews and identify the potential associations between patient-related and location-related factors with miniscrew stability. METHODS: This retrospective cohort study involved 90 orthodontic miniscrews (45 single-thread, 45 double-thread) with identical dimensions (8 mm length, 1.6 mm diameter). The screws were inserted in various locations within the upper jaw of 83 patients (54 females, 29 males; mean age = 15.1 ± 2.4 years). Failure was defined as excessive mobility or loss of miniscrew after placement. The data recorded were patient age, gender, insertion site, side of insertion (buccal or lingual), duration of force application, and failure occurrence. RESULTS: The overall success rate within the sample was 92.2%. Double-thread miniscrews exhibited a significantly higher success rate than single-thread miniscrews (P = 0.049), with 97.8% and 86.7% success rates, respectively. Gender, age, insertion location, and side of insertion did not show significant associations with failure (P > 0.05). Log-rank analysis revealed a significant difference between the two groups (P = 0.046), indicating a higher probability of survival for the double-thread design. CONCLUSIONS: The overall success rate of orthodontic miniscrews was high in the present sample. Double-thread miniscrews placed in various locations within the maxillary arch demonstrated superior stability and survival rates compared to their single-thread counterparts. Therefore, double-thread miniscrews may be preferred when bone quality is inadequate, such as in young patients.

Comparison of the skeletodental effects of miniscrew-anchored and tooth-anchored facemask treatment in growing patients with skeletal class III malocclusions.

INTRODUCTION: This retrospective study aimed to evaluate the skeletal and dental effects of the miniscrew-anchored facemask in skeletal Class III growing patients and compare them with those of conventional tooth-anchored facemasks. METHODS: Retrospectively a total of 50 patients with skeletal Class III (mean ANB: -1.12°) were investigated and divided into two groups according to the treatment modality. Twenty-five patients were treated using the conventional tooth-anchored facemask (T group: mean age 9.3 ± 1.1 years, mean ANB: -0.93°) whereas the other 25 were treated using a miniscrew-anchored facemask (M group: mean age 9.7 ± 1.3 years. mean ANB: -1.61°). Two miniscrews were placed on the palate for bone anchorage. In both T and M groups, facemasks applied a force of 20-30° down on the occlusal plane, and the force increased from 200 g to 300-350 g per side throughout the treatments. The patients were instructed to wear facemasks for at least 14 h per day. A total of 16 angular and 11 linear cephalometric measurements were analysed to determine the skeletal and dental changes before and after facemask treatment. A paired t-test was used to verify the effects before and after treatment in each group. RESULTS: All miniscrews were well maintained during treatment. The values of SNA, SN-ANS, ANB and A to N-Perp, which indicate anterior protraction of the maxilla, were significantly higher in the M group compared with the T group (P < .05). Proclination of the maxillary incisors, extrusion and mesialization of the maxillary molars were significantly greater in the T group (P < .05). CONCLUSIONS: Miniscrew-anchored facemask treatment increased the amount of maxillary protraction and reduced the dental side effects compared with conventional tooth-anchored facemask treatment in growing patients with skeletal Class III malocclusion.

Effect of chlorhexidine mouthwash on gingival health around orthodontic miniscrew implants: A pilot placebo-controlled randomized trial.

OBJECTIVE: This randomized controlled trial (RCT) aims to investigate the short-term effects of chlorhexidine mouthwash (MW) on gingival health surrounding orthodontic miniscrew implants (OMIs) and their overall survivability. MATERIALS AND METHODS: Thirty-two participants (mean age, 22.8 years) undergoing fixed orthodontic appliance treatment after maxillary premolar extraction were randomly allocated in a parallel fashion to either receive (1) MW with an active component of chlorhexidine or (2) a placebo. Each participant received two maxillary buccal OMIs for anchorage reinforcement purposes. Participants were assessed for their gingival oral health status around all inserted OMIs and had their OMI survivability recorded at three time points; T1 = 1 month, T2 = 3 months, and T3 = 6 months after OMI placement. A Kaplan-Meier plot was used to estimate the survival function of OMIs. RESULTS: All randomized participants completed the follow-up period. In terms of gingival oral health, there were no statistically significant differences at any time point between the chlorhexidine MW group and the placebo-controlled group (P > .05). One OMI was lost in the chlorhexidine MW group and another two OMIs in the control group. There was no significant difference between both groups in terms of survivability (P = .585). CONCLUSION: The use of chlorhexidine MW does not seem to have a significant clinical impact on gingival health around OMIs or their survivability in this pilot study.

Three-dimensional comparison of bone-borne and tooth-bone-borne maxillary expansion in young adults with maxillary skeletal deficiency.

OBJECTIVE: To compare the transverse dental and skeletal changes in patients treated with bone-anchored palatal expander (bone-borne, BB) compared to patients treated with tooth and bone-anchored palatal expanders (tooth-bone-borne, TBB) using cone-beam computer tomography (CBCT) and 3D image analysis. METHODS: The sample comprised 30 patients with transverse maxillary discrepancy treated with two different types of appliances: bone-borne (Group BB) and tooth-bone-borne (Group TBB) expanders. CBCT scans were acquired before (T1) and after completion of maxillary expansion (T2); the interval was 5.4 ± 3.4 and 6.2 ± 2.1 months between the T1 and the T2 scans of Group TBB (tooth-bone-borne) and Group BB (bone-borne), respectively. Transverse, anteroposterior and vertical linear and angular three-dimensional dentoskeletal changes were assessed after cranial base superimposition. RESULTS: Both groups displayed marked transverse skeletal expansion with a greater ratio of skeletal to dental changes. Greater changes at the nasal cavity, zygoma and orbital levels were found in Group BB. A relatively parallel sutural opening in an anterior-posterior direction was observed in Group TBB; however, the Group BB presented a somewhat triangular (V-shaped) opening of the suture that was wider anteriorly. Small downward-forward displacements were observed in both groups. Asymmetric expansion occurred in approximately 50% of the patients in both groups. CONCLUSION: Greater skeletal vs dental expansion ratio and expansion of the circummaxillary regions were found in Group BB, the group in which a bone-borne expander was used. Both groups presented skeletal and dental changes, with a similar amount of posterior palate expansion. Asymmetric expansion was observed in both groups.

Evaluation of safe areas for miniscrew use according to various skeletal anomalies with CBCT.

OBJECTIVES: We aimed to determine safe areas to apply miniscrews in the interradicular region of the maxilla and mandible in individuals with various sagittal skeletal malocclusions. MATERIALS AND METHODS: Cone beam-computed tomography images of 159 individuals were used. Individuals were divided into three groups: Class I, Class II, and Class III. In the sagittal plane, 3-6-9-mm apical sections were determined from the alveolar crest apex. The buccal cortical bone thickness, interradicular distance, and buccolingual bone distances were measured. RESULTS: In the buccal cortical bone thickness, we observed statistically significant differences between the classes except for the 1-1 region in the maxilla and all regions and sections in the mandible (p < 0.05). The differences in the buccolingual bone distance between classes were statistically significant, except for the 3-mm and 6-mm sections in the 3-4 and 4-5 regions of the maxilla, the 9-mm sections in the 1-2 and 2-3 regions, the 6-mm and 9-mm sections in the 3-4 region, and the 6-mm section in the 4-5 regions of the mandible (p < 0.05). The differences in the interradicular bone distance were statistically significant between the classes in all regions and sections of the mandible except the 6-mm sections in the 1-2 region and in all sections of the maxilla except the 6-mm sections in the 3-4 region (p < 0.05). CONCLUSIONS: We observed significant differences in the buccal cortical bone thickness, interradicular bone distance, and buccolingual bone distance among individuals. CLINICAL RELEVANCE: Understanding the anatomy of interradicular regions and preventing complications.

Influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors.

OBJECTIVES: To evaluate the influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors. MATERIALS AND METHODS: Patients who completed MARPE treatment at the Radboud University Medical Center between 2018 and 2021 were included in this retrospective study. The papilla height between the maxillary central incisors was evaluated on frontal intraoral photographs taken before expansion (T0) and 1.5 years after MARPE treatment (T1) using the Jemt classification. The difference in Jemt score at T0 and T1 was the primary outcome variable. In addition, gender, age, Angle classification, MARPE duration, midpalatal suture maturation stage, maximal central diastema (MCD) immediately after expansion, crown width to length ratio (W/L), pretreatment overlap of maxillary central incisors, and the distance between the approximal contact point of the central incisors and the bone crest (CP-B) were also record. RESULTS: Twenty-two patients were included (2 men, 20 women, mean age 27.3 ± 8.8 years) and 4 patients (18%) showed a significant reduction in the Jemt score following MARPE (p = 0.04), indicating papilla recession. Interdental papilla recession was significantly associated with the increase of CP-B (p = 0.02), smaller W/L (p < 0.01), overlapping of maxillary central incisors (p < 0.01), and smaller MCD immediately after expansion (p = 0.02). CONCLUSIONS: One and a half years after MARPE, 18% of patients exhibited mild recession of papilla height of the maxillary central incisors. Overlapping and smaller W/L of maxillary central incisors were prognostic factors for interdental papilla recession. CLINICAL RELEVANCE: Clinicians have to be aware of and inform the patients about the occurrence of papilla recession following MARPE.

What is the impact of miniscrew-assisted rapid palatal expansion on the midfacial soft tissues? A prospective three-dimensional stereophotogrammetry study.

OBJECTIVES: To evaluate the midfacial soft tissue changes of the face in patients treated with miniscrew-assisted rapid palatal expansion (MARPE). MATERIALS AND METHODS: 3D facial images and intra-oral scans (IOS) were obtained before expansion (T0), immediately after completion of expansion (T1), and 1 year after expansion (T2). The 3D images were superimposed and two 3D distance maps were generated to measure the midfacial soft tissue changes: immediate effects between timepoints T0 and T1 and overall effects between T0 and T2. Changes of the alar width were also measured and dental expansion was measured as the interpremolar width (IPW) on IOS. RESULTS: Twenty-nine patients (22 women, 7 men, mean age 25.9 years) were enrolled. The soft tissue in the regions of the nose, left of philtrum, right of philtrum, and upper lip tubercle demonstrated a statistically significant anterior movement of 0.30 mm, 0.93 mm, 0.74 mm, and 0.81 mm, respectively (p < 0.01) immediately after expansion (T0-T1). These changes persisted as an overall effect (T0-T2). The alar width initially increased by 1.59 mm, and then decreased by 0.08 mm after 1 year, but this effect was not significant. The IPW increased by 4.58 mm and remained stable 1 year later. There was no significant correlation between the increase in IPW and alar width (r = 0.35, p = 0.06). CONCLUSIONS: Our findings indicate that MARPE results in significant but small changes of the soft tissue in the peri-oral and nasal regions. However, the clinical importance of these findings is limited. CLINICAL RELEVANCE: MARPE is an effective treatment modality to expand the maxilla, incurring only minimal and clinically insignificant changes to the midfacial soft tissues.

The impact of immediate versus delayed mini-screw placement on alveolar bone preservation and bone density following tooth extraction: evidence from a canine model.

The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction of their lateral teeth. In the immediate group, a mini-screw was unilaterally placed approximately 3-4 mm below the alveolar crest of the extraction site on the experimental side. The delayed group received mini-screws six weeks after tooth extraction. On average, the dogs were sacrificed after 11 weeks, and the maxillary bones were excised and scanned using cone-beam computed tomography (CBCT). Histopathological examinations were conducted to assess inflammation and bone formation scores. The results showed that in the immediate group, bone height was significantly greater on the intervention side compared to the control side (p < 0.05), whereas there was no significant difference in the delayed group. In both groups, there was a significant increase in bone density around the mini-screws compared to the control sides (p < 0.05). Mini-screw insertion led to a significant enhancement of bone growth in both groups (p < 0.05), with no notable differences between the two groups. The mini-screws did not have any impact on bone inflammation or width. Overall, both immediate and delayed mini-screw placement in the extraction socket positively influenced bone dimensions, density, and histological properties. However, immediate insertion was more effective than delayed placement in preserving vertical bone height, despite delayed insertion resulting in higher bone density.

Stability of vertical dimension following total arch intrusion.

BACKGROUND: The purpose of this study is to evaluate stability of vertical dimension following total arch intrusion using miniscrews by measuring the change during treatment and relapse amount after more than one year of retention. METHODS: Thirty patients (6 men, 24 women) were included in this study. Lateral cephalographs were taken with conventional radiography at the start of treatment (T0), after treatment (T1), and at least one year after treatment (T2). The evaluation was performed by measuring changes of selected parameters during treatment and the extent of relapse after more than one year. RESULTS: During total arch intrusion treatment (T1-T0), anterior and posterior teeth intruded significantly. The mean vertical distance between the maxillary posterior teeth and palatal plane was reduced by 2.30 mm (P < 0.001). The mean vertical distance between the maxillary anterior teeth and palatal plane was reduced by 2.04 mm (P < 0.001). The anterior facial height was also reduced by 2.70 mm (P < 0.001). During retention period (T2-T1), the vertical distance between the maxillary anterior teeth and the palatal plane significantly increased by 0.92 mm (P < 0.001). The anterior facial height increased by 0.81 mm (P < 0.01). CONCLUSIONS: Anterior facial height significantly decreases after treatment. During retention period, relapse of AFH and maxillary anterior teeth observed. There was no correlation between initial amount of AFH, mandibular plane angle, or SNPog and posttreatment AFH relapse. However, there was a significant correlation between the amount of intrusion of anterior and posterior teeth achieved by the treatment and the extent of relapse.

Long-term efficacy and stability of miniscrew-assisted rapid palatal expansion in mid to late adolescents and adults: a systematic review and meta-analysis.

BACKGROUND: The purpose of this study is to investigate the long-term efficacy and stability of Miniscrew-assisted Rapid Palatal Expansion (MARPE), including its primary outcomes, namely the nasomaxillary complex transverse skeletal and dental expansion, and related secondary outcomes. METHODS: Electronic databases and manual literature searches, up to October 31, 2022, were performed. The eligibility criteria were the following: studies on patients with transverse maxillary deficiency treated with MARPE in adults and adolescents over 13.5 years of age. RESULTS: Ultimately, twelve articles were included in the analysis, one prospective and eleven retrospective observational studies. Five studies showed a moderate risk of bias, while the remaining seven studies were at a serious risk of bias. The GRADE quality of evidence was very low. MARPE is an effective treatment modality for transverse maxillary deficiency (mean success rate: 93.87%). Patients showed increased mean in the skeletal and dental transverse expansion. The basal bone composition, mean alveolar bone and mean dental expansion accounted for 48.85, 7.52, and 43.63% of the total expansion, respectively. There was a certain degree of skeletal and dental relapse over time. MARPE could also cause dental, alveolar, and periodontal side effects, and have an impact on other craniofacial bones, upper airway, and facial soft tissue. CONCLUSIONS: MARPE is an effective treatment for transverse maxillary deficiency, with a high success rate and a certain degree of skeletal and dental relapse over time.

Short-term outcomes in the upper airway with tooth-bone-borne vs bone-borne rapid maxillary expanders.

BACKGROUND: This study compared the area and minimal section of the nasal cavity, nasopharynx, oropharynx, and hypopharynx in cases treated with different methods of microimplant-assisted expansion. METHODS: Based on a pilot study to calculate the sample size, 30 patients with transverse maxillary deficiency over 14 years of age were retrospectively selected. These patients had received two different types of microimplant-assisted maxillary expansion treatment (MARPE and BAME). The patient underwent Cone-Beam computed tomography (CBCT) before and after treatment (mean time 1.5 months) with MARPE or BAME and upper airway measurements (volume and minimum cross-sectional area) were taken to assess upper airways changes and compare changes between the groups. A paired sample t-test was performed to evaluate the T0-T1 change of airway measurements obtained with MARPE and BAME, and a student t-test to compare changes in airway measurements between MARPE and BAME. RESULTS: This investigation shows a statistically significant increase in total nasopharyngeal airway volume (0.59 ± 1.42 cm3; p < 0.01), total oropharyngeal airway volume (3.83 ± 7.53 cm3; p < 0.01) and minimum oropharyngeal cross-section (53.23 ± 126.46 mm2; p < 0.05) in all cases treated with micro-screw assisted expansion. The minimal cross-sectional area of the oropharynx ((79.12 ± 142.28 mm2; p < 0.05) and hypopharynx (59.87 ± 89.79 mm2; p < 0.05) showed significant changes for cases treated with BAME. As for the comparison between cases treated with MARPE and BAME, no differences in upper airway changes have been observed, except for the minimum cross-sectional area of the nasal cavity, which increases for MARPE (52.05 ± 132.91 mm2) and decreases for BAME (-34.10 ± 90.85 mm2). CONCLUSIONS: A significant increase in total area and minimal section at the level of nasopharynx and oropharynx was observed in cases treated with BAME. Regarding the comparison of MARPE and BAME treatments, no differences were found in the total airway volume and minimal section in upper airway except for the minimum cross section of the nasal cavity that increases for MARPE and decreases for BAME.

Evaluation of expansion forces of five pure bone-borne maxillary expander designs anchored with orthodontic mini-implants: An in vitro study.

AIM: This in vitro study investigates the limit of expansion forces and torque wrench forces developed by five skeletal bone expander designs (MICRO 2/4 expanders™) for clinical application. MATERIAL AND METHODS: A total of 30 skeletal expanders were placed in artificial bone blocks and mechanically tested, simulating maxillary expansion. Differences in jackscrew (Dentaurum™ [D], Superscrew™ [S] and Powerscrew™ [P]), number of orthodontic mini-implants (OMIs; two or four) and their placement inclinations (parallel 0° or 10° inclination) form five designs (D4/10°, S4/0°, S4/10°, P4/10° and P2/10°). Expansion forces and torque wrench values were registered, and radiographs were made initially and after 4 mm of expansion. Stress-strain curves were obtained after successive activations and the statistical analysis was performed as appropriate. RESULTS: Plastic deformations in the OMIs and jackscrew occurred around the activation numbers 11-13, with torque wrench values in the range of 500-700 cN. The maximum expansion forces in expanders with four OMIs varied from 93.0 (D4/10°) to 166.6 N (P4/10°) whereas two OMI expanders (P2/10°) registered forces of 79.4 N. Radiographs revealed during loads bending forces (S4/00°, S4/10°) with jackscrew and OMIs deformation in a convex shape, and shear forces (P4/10°, P2/10°) demonstrated only OMIs deformation in a concave shape, providing 15% more expansive force. The jackscrew D4/10° did not have any deformation, but its wire key did not allow reliable activations from activation number 10 and compared to S4/10° and P4/10°, these expanders provided greater expansion forces (P = 0.000 and P = 0.032, respectively). CONCLUSION: The different results obtained in stability and expansion forces indicate that if the activations are carried out under extreme conditions, they may have clinical importance with deformations and non-working expansion mechanics. Jackscrew designs play an important role in expansive forces and expander stability. Torque wrench values can be used clinically as a tool to asses the expansion forces and to avoid deformations.

A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report.

AIM: This case report aimed to present a novel surgical technique involving orthodontics luxation of the offended tooth using miniscrew prior to performing intentional replantation (IR) to remove an extruded separated instrument that injured the inferior alveolar nerve (IAN). BACKGROUND: Intentional replantation is a dental procedure that involves extracting a tooth, managing the root canal, and then reinserting the tooth back into its socket. This procedure is typically used as a last resort when other treatment options have failed or are not possible. Intentional replantation can be successful in preserving the tooth and preventing tooth loss, but it is important to note that there are risks involved. Maintaining the viability of the periodontal ligament (PDL) is a pivotal step to achieve a favorable outcome. CASE DESCRIPTION: A 15-year-old female patient came to the clinic complaining of electric-like pain in the left mandibular posterior area that radiated to the left ear and sometimes caused a headache. Upon clinical and radiographic evaluation, extruded endodontic file from the mesial root of the left first molar that penetrated the IAN canal was noticed. Nonsurgical root canal retreatment was performed, which failed to retrieve the separated file. Orthodontics luxation of the offended tooth was done 2 weeks before the surgical intervention using a miniscrew to induce PDL inflammation, which increased the tooth mobility and PDL volume, facilitating the atraumatic extraction and reduced the risk of complications, such as root resorption and ankylosis. Then, IR was performed, and the extruded file was successfully retrieved. Three months follow-up showed complete recovery of the endodontics-related IAN injury symptoms. Preapical radiographic evaluation and cone-beam computed tomography scan showed complete healing of the periapical radiolucency/area of low density and complete formation of the PDL space and lamina dura around the resected roots. CONCLUSION: This novel approach using a miniscrew suggests a noninvasive technique that minimizes the damage to the offended tooth surrounding tissues as well as minimizing the morbidity of the adjacent teeth and the vital anatomical structures. CLINICAL SIGNIFICANCE: Multidisciplinary comprehensive preplanning of complicated cases is essential to maximize treatment efficiency. The orthodontic extrusion facilitates the extraction process that helps in preserving the PDL, and ultimately increases the survivability of the teeth. How to cite this article: Alharbi MA, Alghamdi BA, Alswajy WA, et al. A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report. J Contemp Dent Pract 2023;24(11):895-901.

[The use of an individualized mini plate for the distalization of teeth]. / Ispol'zovanie individualizirovannoi miniplastiny dlya distalizatsii zubov.

The case of treatment of a 32-year-old patient with complaints about the aesthetics of a smile and the absence of teeth 17 and 46 is presented. During the examination, it was established: the retraction position of the teeth in the frontal part of the upper jaw, the closure of the molars according to the II class of the second subclass of Engl (distal bite), the vestibular position of the teeth 13, 23. To change the spatial position of the lower jaw, the fixation of the bracket system on the upper jaw was performed. and also an individualized mini-plate was installed in the area of the zygomatic alveolar ridge on the right and left, for distalization of the dentition of the upper jaw with the help of orthodontic traction applied from the teeth to the mini-plates. This clinical example demonstrates the possibility of using individualized mini-plates for distalization of the upper dentition, as an alternative and more stable method of treatment in such clinical cases.