Computer-guided miniscrew insertion in the paramedian and parapalatal area of the palatal vault: low failure rate and no learning curve required to obtain predictable results?

AIM: To evaluate the failure rate of palatal computer-guided miniscrews, placed in paramedian and parapalatal regions for orthodontic purposes. In addition, to investigate the presence of a learning curve using computer guided miniscrew insertion, and to evaluate the peri-implant soft tissues response at 2-, 6- and 12- month follow-ups. MATERIALS AND METHODS: 202 palatal computer-guided miniscrews were inserted in 78 subjects for orthodontic purposes. A surgical guide was designed after planning the appropriate insertion sites on three-dimensional images created by the fusion of cone-beam computed tomography (CBCT) and digital dental model images. The devices were disassembled monthly to perform the percussion test and to evaluate the mobility of each miniscrew. To determine the presence of a learning curve, the time of miniscrew failures and the number of surgeries were evaluated. Bleeding on probing (BOP) and probing pocket depth (PPD) were recorded for each miniscrew, at 2- (T0), 6- (T1), and 12-month follow ups (T2). RESULTS: An immediate failure rate of 4.95%, due to lack of primary stability immediately following miniscrew insertion, was recorded, with statistically significant higher failure rate of parapalatal miniscrews (P= 0.00). Miniscrew failure occurred at random time, with an absence of a learning curve. The BOP (mean: 3.13%) and PPD (mean: 1.68mm) measurements remained stable over time. CONCLUSIONS: Computer-guided miniscrew insertion in the palatal vault showed a low failure rate without a determined learning curve to obtain predictable results and with long-term stability of peri-implant soft tissues indexes.

Can computer-guided surgery help orthodontics in miniscrew insertion and corticotomies? A narrative review.

Orthodontics has considerably increased the use of technology combined with surgery as a tool to improve dental movements in terms of predictability, acceleration of movement, and fewer side effects. To achieve these goals miniscrews and corticotomy were introduced. The digital workflow permits an increase in the accuracy of surgical and orthodontic setups. The tool that transfers the information is the CAD/CAM (Computer-Aided Design/ Computer-Aided Manufacturing) template. The aim of this review is to illustrate the use of computer-guided surgery in orthodontics regarding miniscrews and piezocision. The search strategy was a combination of Medical Subject Headings (Mesh) and free text words for PubMed. A total of 27 articles were included in this review: 16 concerned miniscrews and 11 concerned corticotomy. The current need for faster treatments, the improved systems of anchorage, and the evolution of imaging technologies require operators to be knowledgeable of the digital workflow. CAD/CAM templates allow greater precision and predictability of miniscrew insertion even if in the hands of less experienced clinicians and permit a better orientation and depth of the cortical incision. In conclusion, digital planning makes surgery faster and easier and allows for the identification and correction of any potential problem before the procedure.

Friedman Tongue Position and the Anthropometric Parameters in Adult Patients with Obstructive Sleep Apnea: An Observational Study.

INTRODUCTION: Obstructive Sleep Apnea Syndrome (OSAS) is a relevant public health problem; dentists can play an important role in screening patients with sleep disorders by using validated tools and referring patients to a specialist, thereby promoting an interdisciplinary approach. The aim of the study is to identify if the OSAS severity, measured by the apnea-hypopnea index (AHI), and some anthropometric measurements are associated with the Friedman Tongue Position (FTP) within a population with dysmetabolic comorbidities. MATERIALS AND METHODS: A questionnaire containing information about clinical data including height, weight, Body Mass Index (BMI), neck circumference, waist circumference, hip circumference and FTP was administered. The AHI value was measured by means of an unattended home polysomnography device. Pearson correlation coefficients were calculated, and Kruskal-Wallis, Kolmogorov-Smirnov (both nonparametric) and independence tests were performed to probe the possible relationships. The significance was set at p ≤ 0.05. RESULTS: A total of 357 subjects were analyzed. The association between the FTP and AHI was not statistically significant. On the contrary, the AHI showed a positive correlation with BMI and neck circumference. A statistically significant association between the number of subjects with a larger neck and an increasing FTP class was found. BMI, neck, hip and waist circumference was associated with the FTP scale. CONCLUSIONS: although the FTP was not directly associated with OSAS severity, there was also evidence that an FTP increase is associated with an increase in the considered anthropometric parameters, and FTP can be a clinical tool used in the assessment of risk for OSAS risk factors.

Evaluation of nasal airway resistance in a cohort of children with primary snoring and maxillary deficiency.

BACKGROUND: The aim of this study was to test whether rapid palatal expansion is effective to improve nasal airway patency in a sample of pediatric patients with primary snoring. METHODS: A group of 21 subjects, 11 girls (52%) and 10 boys (48%), with a mean age of 7.1 years (SD=1.3; range 4-9 years) were treated with a rapid maxillary expansion (RME) device. Nasal airway resistance was assessed via rhinomanometric exam before (pre-) and 6 months after (post-) the rapid palatal expansion treatment. RESULTS: Data analysis showed a statistically significant increase in the mean scores of the results of the rhinomanometric exam between the pre- and post-measurements with a significant reduction in total inspiratory and expiratory air resistance values after rapid palatal expansion. CONCLUSIONS: Our results show that RME treatment is associated with an improvement in nasal airway resistance due to a substantial reduction in nasal resistance associated with the orthopedic action of the orthodontic device.

Smile esthetic: comparison of perception amongst orthodontists, dental students, orthodontic patients and surgical orthodontic patients

Most patients require orthodontic treatment to improve the esthetics of their smile. Orthodontists must consider how some parameters of mini-esthetics can influence the patient's esthetic perception. Methods: A photograph of the smile of a young female was taken and some modifications were made to the buccal corridor, gingival exposure, smile arc and midline position to assess the influence of these variables on smile attractiveness. Two hundred examiners were selected from four groups: orthodontists (O), dental students (DS), orthodontic patients (OP) and surgical-orthodontic patients (SOP). Each examiner was asked to complete the questionnaire with an approval rating from 1 to 10. Significant level was set at P ≤ 0.05. Results: Only orthodontists considered buccal corridors of 4mm and midline deviation of 1mm as non-esthetic; all other examiners considered gingival exposures ≥3 mm and midline angulation as non-esthetic. All examiners assigned higher satisfaction values to the photo with the concordant smile arc and defined as non-esthetic the covered smile and the reverse smile arc. Patients perceived as non-esthetic only midline deviations of 4mm. The surgical orthodontic patients assigned lower values to the photos and showed greater attention to evaluating the esthetics of the smile than the orthodontic patients. Conclusion: Smile arc, gingival exposure and midline angulation influence smile esthetics; the role of buccal corridors and midline deviation is dependent on the type of examiner

Predictive Analysis of Maxillary Canine Impaction through Sella Turcica Bridging, Ponticulus Posticus Calcification, and Lateral Incisor Anomalies: A Retrospective Observational Study.

Maxillary canine impaction is an increasing dental anomaly and is often related to other dento-skeletal anomalies. The aim of this work is to support the clinician in evaluating the relationship between a displaced maxillary canine and clinical (the features of lateral incisors)/skeletal (ponticulus posticus and sella turcica bridging) anomalies through orthopanoramic radiographs, lateral cephalograms, and plaster casts to identify the parameters that best predict maxillary canine impaction. A retrospective observational study was carried out on the analysis of the medical records, radiographic findings (panoramic radiographs and lateral cephalograms), and plaster casts of 203 orthodontic patients divided into a case group, with at least one impacted maxillary canine, and a control group, without an impaction. A chi-square test and logistic regression analysis were used to analyze the data. A statistically significant association was found between the impaction of the maxillary canine and the female sex, the bridging of the sella turcica, the ponticulus posticus calcification, and the anomaly of the lateral incisor; a logistic regression revealed that these significant variables were found to be positive predictors of impacted maxillary canines, particularly in reference to the impaction in the palatal area. Finding one of these clinical and radiographic elements can represent a predictive sign of the possible impaction of the maxillary canine.

Comparing Distal-Jet with Dental Anchorage to Distal-Jet with Skeletal Anchorage: A Prospective Parallel Cohort Study.

The use of traditional intra-oral devices in maxillary molar distalization is not without undesirable consequences. The aim of the present study was to compare the miniscrew-supported distal-jet appliance to a traditional distal-jet appliance by evaluating the amount of upper first molar distalization and the dentoalveolar side effects. Data of 600 subjects visited at the orthodontic unit of Sapienza University of Rom were analyzed. Only 46 patients met the inclusion criteria and were selected and treated. Subjects were assigned randomly to receive treatment either with miniscrew-supported distal-jet appliance (Group A) or with a traditional distal-jet appliance (Group B). In Group A, miniscrews were inserted using a computer-guided surgical guide. The amount of upper first molar distalization and the dentoalveolar side effects were assessed both on the digital casts and on the lateral cephalometric radiograph at the end of the distalization phase. A descriptive statistical analysis that included the mean values and the standard deviation was conducted to evaluate the molar distalization and the dentoalveolar effects in two groups. Intergroup differences were determined using the Student's t-test. The significance was set at p ≤ 0.05. In Group A, greater maxillary first molar distalization and a spontaneous distalization of the first premolars and a palatal inclination of central incisors were observed. By contrast, in Group B, the first premolars tipped mesially and a proclination of the maxillary central incisors was observed. In both groups, the transverse widths of the dental arch increased while a greater tendency of first premolar extrusion and of maxillary first molar rotation was observed in Group B. The skeletal anchorage device achieved greater first molar distalization and did not cause dento-alveolar side effects.

Early Class III Treatment Using a Hybrid Rapid Palatal Expander and Facemask in a Patient with Partially Edentulous Maxilla Post MNTI Removal: A Case Report.

This case report describes the orthodontic treatment of a 9-year-old girl who presented with multiple agenesis, maxillary contraction, and skeletal Class III malocclusion after the surgical removal of a melanocytic neuroectodermal tumour of infancy (MNTI) or the so-called melanocytic progonoma at 40 days of age. The lack of dental anchorage in the posterior segment of the second quadrant and the search for maximum control during suture expansion to reduce dental effects led to the use of a hybrid rapid palatal expander (RPE) with dental anchorage in the first quadrant and skeletal anchorage on the two miniscrews placed in the second quadrant, to allow a more even distribution of expansion forces. The expansion procedures performed with the hybrid anchorage device and extraoral traction demonstrate the possibility of solving the contraction in the posterior segments and anterior crossbite in a few months with maximum control of the applied forces, despite the objective difficulties related to the specificity of the case.

OSAS Severity and Occlusal Parameters: A Prospective Study among Adult Subjects with Comorbidities.

INTRODUCTION: OSAS is an emerging public health problem. Early diagnosis in adults with comorbidities is the gold standard to avoid complications caused by a late diagnosis. The aim of the study, part of the SLeeP@SA project, was to identify within a population with dysmetabolic comorbidities the association of occlusal clinical signs, defined by orthodontic parameters, and of the anthropometric phenotype, with the severity of OSAS. MATERIALS AND METHODS: A dedicated questionnaire containing questions regarding the presence of deep bite, augmented overjet, partial edentulism, and bruxism was completed by clinic staff. OSAS was evaluated using an unattended home PSG device, which recorded the AHI value. BMI and neck circumference were also measured. The Kolmogorov-Smirnov test was performed to evaluate the association of the AHI with occlusal clinical signs. The significance was set at p ≤ 0.05. The association of AHI with BMI and neck circumference was evaluated with the Pearson correlation coefficient. RESULTS: In total, 199 subjects were evaluated. No statistically significant association between occlusal parameters and AHI was found, while the AHI showed a positive correlation with BMI and neck circumference. The neck circumference seemed to be a better clinical predictor for OSAS severity than BMI, especially for females. CONCLUSIONS: These results highlight how the orthodontic clinical data alone are not sufficient to establish an association between occlusal anomalies and OSAS severity, but further investigation involving a specialist orthodontic diagnosis is necessary.

Are the Insertion Torque Value and Implant Stability Quotient Correlated, and If So, Can Insertion Torque Values Predict Secondary Implant Stability? A Prospective Parallel Cohort Study.

PURPOSE: Primary stability is the most important prognostic index for predicting osseointegration. It is generally thought that to achieve high primary stability, it is necessary to insert an implant with a high insertion torque (IT). To date, it has not yet been determined whether IT and implant stability quotient (ISQ) values are correlated. The primary aim of the study was to determine the correlation between IT and ISQ values at the time of implant insertion (T0); at 2 months, the time of healing (T1); and at 6 (T2) and 12 months (T3) after loading. The secondary aims were to determine the influence of different macroscopic implant designs and of a different insertion arch on this correlation; and to assess whether implants inserted with a high IT, that is, > 50 Ncm, had higher levels of implant stability at 2-, 6-, and 12-month follow-ups. MATERIALS AND METHODS: STROBE guidelines were followed. Partially or monoedentulous patients were randomly assigned to receive taper thread on straight-body implants with microthreads (group A) or without microthreads (group B). At implant insertion, IT and ISQ values were recorded. At 2-, 6-, and 12-month follow-ups, the ISQ values were recorded. A spring-style torque wrench was used to assess the IT. The Osstell device was used to determine the ISQ values. Descriptive statistics, Pearson correlation, and t test were used. P was set at ≤ .005. RESULTS: Two hundred fifty subjects were assessed; 142 were included. Two hundred sixty-eight implants were inserted (group A, 137 implants; group B, 131 implants). No subject dropped out, and no implant failed. A statistically significant correlation between ISQ and IT was determined at the time of implant insertion (T0; P = .000). The implant morphology and arch did not influence the correlation. An IT > 50 did not determine a higher secondary stability. CONCLUSION: There is a strong correlation between IT and primary stability, but IT is not correlated with the secondary stability. A different implant macroscopic design and a different arch of insertion did not influence this correlation. Moreover, implants inserted with IT > 50 Ncm do not result in greater secondary stability.

Comparison of changes in skeletal, dentoalveolar, periodontal, and nasal structures after tooth-borne or bone-borne rapid maxillary expansion: A parallel cohort study.

INTRODUCTION: This parallel cohort study aimed to assess the dentoalveolar, skeletal, periodontal, and airway effects of tooth-borne (hyrax) and computer-guided miniscrew-supported rapid palatal expansion appliances. METHODS: Thirty-six subjects were randomly allocated into 2 groups. Eighteen subjects (mean age, 12.2 years; male-to-female ratio, 10:8) were assigned to receive treatment with the hyrax appliance (group A), and 18 subjects were treated with the computer-guided miniscrew-supported appliance (group B). The same type of expansion screw and expansion protocol was used in both groups. Linear and angular measurements of skeletal, dentoalveolar, periodontal, and nasal floor changes were performed on the pretreatment and posttreatment cone-beam computed tomography images (6-month follow-up). Descriptive statistics and the independent Student t test were used for the statistical analysis. Intraoperator reliability was evaluated using a 2 sample t test. The level of significance was P ≤0.05. RESULTS: Ten subjects were censured because posttreatment cone-beam computed tomography imaging was not performed because of the coronavirus disease 2019 pandemic. In the remaining 26 subjects, increases in linear measurements were observed in both groups. The transversal skeletal increase was greater and statistically significant in the group treated with the bone-borne expander (P ≤0.05). The dentoalveolar transverse diameters were greater in the tooth-supported expander group, with no statistically significant difference between the groups. The buccal inclination of the maxillary first molar was observed in the group with the tooth-borne expander, with a statistically significant difference between the 2 groups. A slight reduction of buccal and palatal thicknesses at the level of the maxillary first molars was observed in both groups, smaller in the skeletal expander group, with a statistically significant difference between the 2 groups only on the right buccal cortical plate. The width of the nasal floor increased more in the group with skeletal expander with a statistically significant difference of 2 mm. CONCLUSIONS: Computer-guided miniscrew-supported maxillary expanders allowed a greater transversal increase of the nasal-maxillary skeletal structures by reducing the dentoalveolar side effects of the tooth-supported devices.

Computer-Guided Bone Biopsy: A Technical Note with the Description of a Clinical Case.

AIM: The aim of this technical note is to present a computer-aided design-computer-aided manufacturing (CAD-CAM) surgical guide to perform a computer-guided bone biopsy. Traditionally, to diagnose abnormal conditions affecting jawbone, a bone biopsy is performed with the use of a trephine bur. The positioning of the bur, during the biopsy, is based on the skill of the surgeon; therefore, an inaccurate placement of a trephine bur may occur. The use of a guide, however, can minimize this risk and achieve a better result. MATERIALS AND METHODS: To determine the site and the extension of bone sampling, the stereolithography file (STL) file of cone-beam computed tomography (CBCT) images is acquired using a specific planning software and superimposed with the STL file of a dental cast; a virtual surgical guide is designed, using the same software that allows a 3D (three-dimensional) view of the guide from different perspectives and planes. The number and site of guide tubes are determined on the basis of the width and the extension of the sampling; thanks to a 3D printer, the surgical guide is manufactured. RESULTS: The use of a customized surgical guide realized with CAD-CAM technology allows a precise and minimally invasive approach, with an accurate three-dimensional localization of the biopsy site. CONCLUSIONS: The high precision, great predictability, time-effectiveness and versatility of the present guide should encourage the clinician to use this minimally invasive surgical approach, but controlled clinical trials should be conducted to evaluate the advantages as well as any possible complications.

Periodontal results of different therapeutic approaches (open vs. closed technique) and timing evaluation (< 2 year vs. > 2 year) of palatal impacted canines: a systematic review.

BACKGROUND: This review evaluates, as a primary outcome, which surgical technique (open vs. closed) and which type of material used for the auxiliaries (elastic vs. metallic) were preferable in terms of periodontal results during the treatment of palatal-impacted canines. The timing of the evaluation of the results was also assessed as a secondary outcome. METHODS: An electronic search of the literature up to March 2021 was performed on Pubmed, MEDLINE (via Pubmed), EMBASE (via Ovid), Cochrane Reviews and Cochrane Register of Controlled Trials (RCTs) (CENTRAL). The risk of bias evaluation was performed using version 2 of the Cochrane risk of bias tool (RoB 2) for RCTs and the ACROBAT NRSI tool of Cochrane for non-RCTs. RESULTS: 11 articles met the inclusion criteria. Only one RCT was assessed as having a low risk of bias and all the non-RCTs were assessed as having a serious risk of bias. This review revealed better periodontal results for the closed technique and metallic auxiliaries. In addition, it revealed that the timing of the evaluation of the results affects the periodontal results with better results obtained 2 years after the end of treatment. CONCLUSION: In the treatment of a palatal-impacted canine, the closed technique and metallic auxiliaries should be preferred in terms of better periodontal results. The timing of the evaluation of the results affects the periodontal results.

Comparision of profile macro-estethic perception among orthodontists, dentistry students, orthodontic patients and surgical orthodontic patients.

BACKGROUND: The patient's needs should guide the orthodontist in choosing the most appropriate therapy. The purpose of the present survey was to compare the esthetic perception of the facial profile by orthodontists (O), dentistry students (DS), orthodontic patients (OP) and surgical-orthodontic patients (SOP) and to evaluate the influence of gender, age and level of study. MATERIAL AND METHODS: A facial profile photograph of a young female was taken and twelve modified images were made, altering the position of the jaws in protrusion and in retrusion. Two hundred caucasian examiners, divided into four groups (O, DS, OP, SOP), were selected. Each examiner was asked to complete the questionnaire with an approval rating from 1 to 10. An ordinary least square OLS model was applied. Significant levels were set at P ≤ 0.05. RESULTS: All examiners considered a straight profile or a slight retrusion of the maxilla as the most attractive profile. Slight discrepancies (up to 2 mm) in jaw protrusion were barely perceived by patients. Mandibular retrusion (2 and 4 mm) was one of the least appreciated condition by all examiners. Surgical-orthodontic patients assigned lower ratings compared to orthodontic patients. Female subjects assigned lower ratings than males. Patients with secondary school education assigned higher statistically significant values compared to other levels of study. The lowest values were attributed by the sample of age > = 17 years. CONCLUSIONS: The choice of the most appropriate therapy is based not only on a correct diagnosis, but on the evaluation of esthetic and psychological aspects. Key words:Estethic, profile, orthodontic, surgical orthodontic patients.

Uprighting Impacted Mandibular Second Molar Using a Skeletal Anchorage: A Case Report.

The aim of this case report is to present an innovative combined orthodontic-surgical technique to disimpact mandibular second molar (MM2) using an orthodontic miniscrew and an elastic chain. The impact on the Oral health-related quality of life (OHRQoL) was also evaluated. Using the present techinique, it is possible to expose the impacted tooth, insert a self-drilling miniscrew in the retromolar area, and remove the bud of third mandibular molar. At the same time the orthodontic force is applied with the use of an elastomeric chain that connects the head of miniscrew and vestibular and oral buttons bonded on MM2. A close traction is performed for the whole treatment time without the reactivation of the elastic force. The use of skeletal anchorage allowed the disimpaction of impacted MM2 in a short treatment time (about three months) avoiding the typical biomechanical side effects of traditional orthodontic appliance and increasing the effectiveness of the treatment. Further studies are necessary to evaluate the real advantages and disadvantages of this combined orthodontic-surgical approach.

The impact of tooth-borne vs computer-guided bone-borne rapid maxillary expansion on pain and oral health-related quality of life: A parallel cohort study.

INTRODUCTION: The primary aim of this study was to investigate and compare perceived pain intensity and oral health-related quality of life (OHRQOL) results during the activation phase of rapid maxillary expansion (RME), with tooth-borne and bone-borne devices. In addition, a secondary aim of this study was to evaluate the correlation between pain scales and the shortened Oral Health Impact Profile (OHIP-14) questionnaire. METHODS: Thirty-six subjects (16 girls and 20 boys) with a mean age of 12.3 years (standard deviation, 0.82 years) were randomized into 2 groups. Group A received treatment with hyrax appliance, and group B received a computer-guided skeletal RME appliance. The same type of expansion screw and screw activation or expansion protocol were used. Two rating scales were used to assess the subject's pain during the activation phase of RME: a Graphic Rating Scale for Pain (GRS) and the Wong-Baker Faces Pain Scale (FPS). The OHIP-14 was used to evaluate the impact of RME on OHRQOL before the beginning of the treatment at day 3 and day 7 follow-ups. Painkillers were forbidden during the active phase of RME. Descriptive statistics, Student t test, and Pearson correlation were used. Significance was set at P ≤0.05. RESULTS: A total of 36 subjects, divided into 2 groups, were treated in the study. Regarding the level of pain, the Student t test showed statistically significant higher pain in group B-although only on the first day of screw activation (GRS, P = 0.01; FPS, P  <0.01). For the following days, there were no significant differences in pain levels between groups. The OHIP-14 showed no statistically significant difference at baseline (P = 0.32) and day 3 (P = 0.88) and day 7 (P = 0.85) follow-ups between the 2 groups. The Pearson correlation coefficient showed a statistically significant association between the 2 different scales of pain (GRS and FPS) but not a statistically significant correlation between GRS and FPS scales and OHIP-14. CONCLUSIONS: A higher perceived pain intensity in the patients treated using a bone-borne computer-guided skeletal RME appliance was limited to the first day of screw activation. There were no statistically significant differences between the 2 types of treatment in terms of their impact on OHRQOL and no statistically significant correlation between pain scales and the OHIP-14 questionnaire.

Split crest technique for implant treatment of agenesis of the upper lateral incisors: results of a randomized pilot histological and clinical study at 24-month follow-up.

Agenesis of lateral incisors, besides the functional issues, represents a great esthetic drawback. The selection of an appropriate treatment is a complex decision, which should consider the stability of the clinical outcomes over time. The aim of the present study was a histological and clinical comparison of two-stage split crest technique (SCT), with bone chips alone or mixed with porcine bone in patients affected by unilateral and bilateral agenesis of the upper lateral incisors. Eleven patients were enrolled, and randomly assigned to receive a treatment with autologous bone chips (group 1) or autologous bone chips mixed 1:1 to porcine-derived xenogenic bone (group 2). After a 2-month healing period, implants were placed and biopsies harvested for histomorphometrical evaluation. Clinical assessment, according to ICOI PISA health scale, and radiographic marginal bone loss evaluation at 12- and 24-month follow-ups were conducted. The histomorphometry showed significantly greater new bone formation (p > 0.0229) in group 2. At 12- and 24-month follow-ups, all the evaluated implants, regardless of the group they were allocated, could be categorized as "success" in the ICOI Pisa Health Scale for Dental Implants, and did not show significant difference in crestal bone loss. To the best of our knowledge, these are the first histological and clinical outcomes indicating that the use of bone chips mixed 1:1 to porcine bone in SCT could be a promising technique for the rehabilitation of patients with agenesis of the upper lateral incisors, although studies with a larger number of patients and implants, and a longer follow up are needed.

Computer-guided palatal canine disimpaction: a technical note.

AIM: To present a minimally invasive approach to solve the impaction of palatal canines using computer-guided orthodontic miniscrews. MATERIALS AND METHODS: Miniscrew-supported appliances for palatal canine disimpaction are performed with CAD/CAM technology. With adequate software, it is possible to match the STL files of the dental arch with the DICOM images of the maxilla, previously transformed into STL files. The ideal points for miniscrew insertion can be identified on the STL 3D model file on the basis of the width and thickness of the palatal vault. A software application allows for the design of the surgical guide, which is printed using a 3D printer. The virtual position of the planned miniscrews is transferred onto a printed dental cast on which the orthodontic device is realized. On the day of surgery, both the surgical guide and the orthodontic appliance are ready for use. RESULTS: Miniscrew insertion and palatal canine disimpaction can be achieved in one surgical procedure. CONCLUSION: The use of computer-guided skeletal anchorage allows for both the reduction of the biomechanical side effects typical of conventional treatment and the risk of damaging adjacent anatomical structures, increasing the effectiveness of treatment. Controlled clinical trials are necessary to evaluate more fully any advantages of this minimally invasive technique.

Relationship between upper lateral incisors anomalies and palatal displaced canine: a case-control retrospective study.

BACKGROUND: An observational case-control study was designed to retrospectively assess the association among sex, skeletal and dental variables and the and the palatal maxillary canine impaction. METHODS: The STROBE guidelines were followed. The records of 2195 subjects were analyzed. The data records of subjects with palatally displaced canine (PDC) were compared with the data of randomly selected subjects without PDC. Descriptive statistics, logistic regression model and χ2 test were used. RESULTS: One hundred and one subjects presented at least one PDC; 106 subjects without PDC were randomly selected. From the logistic model, it was found that only gender and persistence of the deciduous canine were significantly associated with PDC. The Chi-square test showed a correlation between the presence of upper lateral incisor anomalies and PDC, otherwise, considering the unilateral impaction, there was no statistically significant difference in the relationship between canine impaction and the presence of the lateral incisor anomalies, on the same or opposite side of the impaction. CONCLUSIONS: The female sex and the persistence of maxillary deciduous canines are associated with PDC. The anomalies of the lateral incisor do not seem to play a mechanistic role, but could rather represent a genetic variable of the canine eruption disorder.

The combined use of clear aligners and computer-guided piezocision: a case report with a 2-year follow-up.

AIM: An orthodontic treatment is described that combines the use of clear aligners and computer-guided piezocision to overcome the drawbacks of traditional corticotomy in accelerating orthodontic tooth movement. The relapse at the 2-year follow-up was also evaluated. MATERIALS AND METHODS: A 13-year-old male patient was selected and treated due to a molar Class II malocclusion with moderate dental crowding. Treatment time, oral health-related quality of life (OHRQoL), and periodontal indexes were assessed. To reduce the treatment time, computer-guided piezocision was utilized to perform flapless interproximal corticotomy cuts through the depth of the cortical bone. The orthodontic therapy using clear aligners began on the same day as the surgery. RESULTS: The overall duration of the therapy was 6 months. There was an improvement in the periodontal indexes at the end of the therapy. An aggravation of OHRQoL only occurred for 3 days after surgery. The 2-year follow-up evaluation showed a relapse of 0.2 mm on the maxillary left lateral incisor and 0.25 mm on the mandibular right lateral incisor. CONCLUSION: The present case report describes the advantages of a combination of computer-guided piezocision and clear aligners to treat a Class II malocclusion with moderate crowding.