Palatal Bone Thickness Research Articles

Gender-Based Variation in Alveolar Bone Thickness of Maxillary Incisor Teeth: A CBCT Retrospective Study.

BACKGROUND This retrospective study from a single center in Cyprus aimed to assess labial (buccal) and palatal bone thickness in 6 anterior maxillary teeth of 120 adults using cone-beam computed tomography (CBCT). MATERIAL AND METHODS The CBCT scans of 120 patients (720 teeth) were examined, with scanning parameters of 90 kvP, 24 s, 4 mA, voxel size 0.3 mm, and field of view of 10×6 cm. All maxillary incisors were categorized into 3 distinct points in terms of buccal (B) and palatal (P) points, with points B1 (buccal) and P1 (palatal) 4 mm below the cementoenamel junction; points B2 and P2 at the midpoint between the labial and palatal alveolar crest plane extending to the root apex; and points B3 and P3 at the root apex. Evaluation was done by measuring the distance from these points to the labial and palatal alveolar bone. RESULTS When the thicknesses were measured between all 6 points and labial and palatal bone, the thickness of point B3 of tooth 13 in men was significantly higher than that in women. At points P1, P2, and P3 for teeth 11 and 13, the palatal bone thickness of men was significantly higher than that of women. At points P2 and P3 of tooth 12, the palatal bone thickness of men was significantly higher than that of women. CONCLUSIONS The study found a correlation between alveolar bone thickness and patient sex in the North Cyprus population. Alveolar bone thickness in the anterior maxillary should be considered in implant treatment and orthodontic techniques.

Effect of Slow Maxillary Expansion and Alternative Rapid Maxillary Expansion Protocols on Airway Volume in Cleft Palate Cases: A Cone Beam Computed Tomography Based Study.

A total of 22 patients with cleft palate aged 8 to 12 years were selected and categorized into two groups: the first group was treated with alternate rapid maxillary expansion and constriction (Alt-RAMEC) using an expander with differential opening (EDO) and facemask, while the second group was treated using slow maxillary expansion (SME) using an EDO. Finally, the pharyngeal airway volume in the two groups was compared using cone beam computed tomography (CBCT). CBCT scans were performed before expansion and six months following the expansion. Alveolar crest level, maxillary breadth, nasal cavity width, arch width, inclination of the molar teeth, buccal and palatal alveolar bone thickness, and maxillary alveolar width were all assessed. Paired t-tests (p=0.05) were applied to compare interphase data. The two groups showed a non-significant difference in terms of nasopharyngeal volume (cm3), oropharyngeal volume (cm3), and overall pre- and post-treatment results (p>0.005). Results of comparison of pre- and post-treatment periods in the Alt-RAMEC group revealed a significantly higher cleft volume (cm3) (p=0.001). Results of comparison of pre- and post-treatment periods in the SME group revealed a substantial rise in cleft volume (cm3) (p=0.003).Results from a comparison of the cleft volume (cm3) between the two study groups pre- and post-intervention revealed a non-significant difference (p=0.200 and 0.054, respectively).

Evaluation of nasal septal deviation and maxillary bone and nasal airway dimensions and volumes using cone-beam computed tomography in patients with unilateral palatal canine displacement: a retrospective study.

To detect any association between palatally displaced canine (PDC) and nasal septal deviation (NSD), palatal bone thickness and volume, and nasal airway dimensions and volume. A total of 92 patients were included and subdivided into two groups: group 1, unilateral PDCs (44 patients), and group 2, normally erupted canines (NDCs) (48 subjects). The following variables were measured using cone-beam computed tomography: presence and type of NSD, nasal width, inferior conchae, hard palate and nasal septum thickness, maxillary bone and nasal airway volumes. NSD was detected in 77% and 50% of PDC and NDC subjects, respectively. Within the PDC subjects, significant differences between the displaced and nondisplaced sides were detected. Palate thickness was increased in the canine region and reduced in the molar region. Compared with the control group, PDC subjects had reduced palate thickness and lower nasal airway volume. Two predictors were significant for predicting the odds of PDC occurrence: NSD and maxillary bone volume. NSD is more frequent in PDC subjects. PDC subjects have reduced palate thickness and decreased nasal airway volume. In the presence of NSD, the odds of developing PDC increase by 3.35 times, and for each one-unit increase in the maxillary bone volume, the odds of developing PDC decrease by 20%.

Comparison of alveolar bone morphology after expansion with hybrid and conventional Hyrax expanders.

To compare the buccal and palatal bone changes of maxillary posterior teeth produced by hybrid hyrax (HH) and conventional hyrax (CH) expanders in growing patients. A sample of 32 patients with posterior crossbites in the late mixed dentition was recruited and randomly allocated into two groups. Group HH was composed of 18 individuals with a mean age of 10.7 years (six female, 12 male) treated with a hybrid expander with two anterior parasagittal miniscrews. Group CH was composed of 14 individuals with a mean age of 11.4 years (six female, eight male) treated with a conventional Hyrax expander. Cone-beam computed tomography (CBCT) exams were obtained before expansion (T1) and after 11 months when the expander was removed (T2). Buccal and palatal bone plate thickness and height of maxillary posterior teeth were measured. Intergroup comparisons were performed using t or Mann-Whitney tests (P < .05). The CH group showed greater decreases of the buccal bone plate height (mean change: 1.27 mm) at the maxillary first premolars compared to the HH group (mean change: 0.11 mm, P = .001). No intergroup difference was found for changes in the buccal and palatal bone thickness. Hybrid expanders showed a tendency to cause less negative impact on the buccal bone plate height of first premolars compared to conventional Hyrax expanders. However, the difference was not clinically significant. Both hybrid and conventional Hyrax expanders are safe for the alveolar bone morphology in the late mixed dentition.

A Novel Dental Implant Approach for Crestal Sinus Elevation: A Case Series Study.

The aim of this study was to evaluate the radiographic and clinical outcomes of patients undergoing sinus membrane elevation via a minimally invasive crestal approach utilizing the dental implant. Twenty patients having 1 or more missing posterior teeth were included. The maxillary sinus membrane was elevated using dental implant via a crestal approach in areas with insufficient residual bone. CBCT scans were used to measure the amount of newly formed bone, implant length inside the sinus, bucco-palatal sinus width, and bone thickness. Surgical and postsurgical complications along with implant survival were also measured. The mean (±SD) values for the newly formed bone after 1 year were 2.4 (±1.87) mm, while values for implant length inside the sinus were 4 (±1.49) mm. The results showed that percentage of implant length inside the sinus and the palatal bone thickness were statistically significant positive predictors of the newly formed bone. Higher percentage of implant length inside the sinus and increased palatal bone thickness were associated with larger amounts of newly formed bone. A high patient satisfaction was reported along with a 100% implant survival. The utilization of the novel dental implant approach for crestal sinus elevation demonstrated predictable clinical and radiographic outcomes. This novel technique is simple to both patients and clinicians, rendering it a promising and cost-efficient procedure.

Recovery bone formation on radiographic palatal bone dehiscences after incisor retraction with microimplants.

To investigate the difference in labial and palatal alveolar bone thickness and height during the retention period after incisor retraction treatment with microimplant. A sample of 21 patients (mean age: 17.80 ± 4.38 years) who underwent incisor retraction treatment using microimplants after premolar extraction was investigated. The cone-beam computed tomography images at pretreatment, posttreatment, and retention were used to measure anterior alveolar bone thickness (labial, palatal, and total; at three vertical levels) and height (labial and palatal) and differences in the incisor position during treatment or retention. Repeated-measures analysis of variance with Bonferroni correction was performed to compare the variables at T0, T1, and T2. The maxillary central incisor moved posteriorly by approximately 8.0 mm along with intrusive movement of 1.8 mm after treatment. The alveolar bone thickness significantly decreased on the palatal side and increased on the labial side after treatment. Thereafter, the palatal bone thickness significantly increased and labial bone thickness decreased during the retention period. The palatal interdental bone depressed by incisor retraction showed substantial bone deposition after retention. Radiographic palatal bone dehiscences on the incisor root and palatal bone depression between the incisor roots were apparent after treatment. This palatal bone loss around the incisor roots noticeably recovered with newly formed bone during retention.

EVALUATION OF PALATAL BONE THICKNESS ON LATERAL CEPHALOGRAM AND ITS COMPARISON WITH CBCT SCANS

Aim: Aim of this study is to evaluate the palatal bone thickness on lateral cephalogram and its comparison with CBCT scans in different growth patterns and to find the gender differences if exists in palatal bone thickness at various measuring sites. Materials and Method: In this study 90 subjects with age ranging from 16-25 years visiting the Department of Orthodontics were chosen. Subjects were categorized into average, horizontal and vertical growth pattern groups according to Jarabaks ratio. They were further divided into male and female group to determine gender dimorphism if any. Palatal bone height was measured antero-posteriorly at a distance of 3, 6, 9, 12, 15, 18, 21 and 24 mm posterior to incisive canal both on lateral cephalogram and CBCT. Results: This study showed the palatal bone thicknessonlateral cephalograms is less when compared to CBCT at all the distances from incisive canal (p&lt;0.0001). The horizontal growth pattern showed highest palatal bone thickness at all the intervals followed by average and vertical and a statistically significant difference was found between the three groups (p&lt;0.0001). Independent t test reported higher amount of bone thickness in males as compared to females on both lateral cephalogram and CBCT (p&lt;0.05). Conclusion: Lateral Cephalogram showed less bone thickness when compared to CBCT. Horizontal growth pattern showed highest amount of bone thickness followed by average and vertical growth pattern.

Quantification of the apical palatal bone index for maxillary incisor immediate implant assessment: A retrospective cross-sectional study

BackgroundApical palatal bone is important in immediate implant evaluation. Current consensus gives qualitative suggestions regarding it, limiting its clinical decision-making value. ObjectivesTo quantify the apical palatal bone dimension in maxillary incisors and reveal its quantitative correlation with other implant-related hard tissue indices to give practical advice for pre-immediate implant evaluation and design. Material and methodsA retrospective analysis of immediate implant-related hard tissue indices in maxillary incisors obtained by cone beam computed tomography (CBCT) was conducted. Palatal bone thickness at the apex level (Apical-P) on the sagittal section was selected as a parameter reflecting the apical palatal bone. Its quantitative correlation with other immediate implant-related hard tissue indices was revealed. Clinical advice of pre-immediate implant assessment was given based on the quantitative classification of Apical-P and its other correlated immediate implant-related hard tissue indices. ResultsApical-P positively correlated with cervical palatal bone, whole cervical buccal-palatal bone, sagittal root angle, and basal bone width indices. while negatively correlated with apical buccal bone, cervical buccal bone, and basal bone length indices. Six quantitative categories of Apical-P are proposed. Cases with Apical-P below 4 mm had an insufficient apical bone thickness to accommodate the implant placement, while Apical-P beyond 12 mm should be cautious about the severe implant inclination. Cases with Apical-P of 4–12 mm can generally achieve satisfying immediate implant outcomes via regulating the implant inclination. ConclusionsQuantification of the apical palatal bone index for maxillary incisor immediate implant assessment can be achieved, providing a quantitative guide for immediate implant placement in the maxillary incisor zone.

Pattern of microimplant displacement during maxillary skeletal expander treatment: A cone-beam computed tomography study.

To analyze the microimplant (MI) displacement pattern on treatment with a maxillary skeletal expander (MSE) using cone-beam computed tomography (CBCT). Thirty-nine participants (12 males and 27 females; mean age, 18.2 ± 4.2 years) were treated successfully with the MSE II appliance. Their pre- and post-expansion CBCT data were superimposed. The pre- and post-expansion anterior and posterior inter-MI angles, neck and apical inter-MI distance, plate angle, palatal bone thickness at the MI positions, and suture opening at the MI positions were measured and compared. The jackscrew plate was slightly bent in both anterior and posterior areas. There was no significant difference in the extent of suture opening between the anterior and posterior MIs (p > 0.05). The posterior MI to hemiplate line was greater than that anteriorly (p < 0.05). The apical distance between the posterior MIs was greater than that anteriorly (p < 0.05). The palatal thickness at the anterior MIs was significantly greater than that posteriorly (p > 0.01). In the coronal plane, the angulation between the anterior MIs in relation to the jackscrew plate was greater than that between the posterior MIs owing to the differential palatal bone thickness.

Morphometric evaluation of alveolar bone after orthodontic treatment of multiple impacted teeth in the unilateral maxillary anterior region

This study aimed to investigate the height and thickness of alveolar bone by cone-beam computed tomography imaging after orthodontic treatment in the unilateral maxillary anterior region and speculate on reasons for the difference in alveolar bone morphology. This study selected 11 patients (3 males and 8 females; mean age, 9.42 ± 1.45 years). Cone-beam computed tomography was performed for these 11 patients before and after treatment using Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). Labial and palatal alveolar bone thickness (BT) at root apices and different levels along the roots and loss of alveolar bone height was measured for each impacted tooth and its contralateral homonymous tooth. After orthodontic therapy, all 3 impacted anterior teeth had different degrees of loss of labial alveolar bone height compared with the normal side (central incisor: -1.5 mm, P<0.005; lateral incisor: -1.06 mm, P<0.01; canine: -0.59 mm, P< 0.01). The lateral incisors also showed palatal alveolar bone height loss compared with the unaffected side (-0.8 mm, P<0.005). Alveolar BT at root apices of impacted canines was 1.14 mm thicker than the normal side (P<0.005). Central and lateral incisors were similar to the normal side. The thickness of the alveolar bone at 8, 10, and 12 mm of the impacted canine position was still larger than that on the healthy side, whereas the difference in average thickness between the healthy and affected side had been significantly reduced compared with pretreatment measurements. There is satisfactory retention of alveolar bone height in canines after orthodontic treatment; however, alveolar bone loss is slightly worse at central and lateral incisors. Retention of alveolar BT was normal for impacted anterior teeth, whereas excess apical alveolar BT at the canines, although still present, was substantially less significant than had been observed before treatment.

Evaluation of Palatal Bone Thickness at the Implantation Areas of Two Popular Bone-Anchored Distalizers-A Cone Beam Computed Tomography Retrospective Study.

Since class II malocclusion and lack of space within the dental arch due to early loss of deciduous molars is a common orthodontic problem in the Polish population, bone-anchored distalizers are becoming more and more popular. The aim of the present study was to evaluate palatal soft and hard tissue thickness using cone beam computed tomography (CBCT) at the area of micro-implant placement of two appliances for maxillary first molar distalization: Beneslider and TopJet distalizer. The study data were 100 consecutively selected CBCT images (53 of men and 47 of women). Measurements of bone and mucosa thickness were performed at six locations in the palate and tested according to their correlation with sex and age. The biggest bone and mucosa thickness were recorded in the insertion site of the TopJet miniscrew. Bone thickness in all points of paramedian insertion was significantly greater in males and the mean difference was approximately 1-1.8 mm. Age correlates significantly (p < 0.05) and positively (r > 0) with the thickness of the mucosa at all points: the older the patient, the thicker the mucosa at each measurement point. Anatomical diversity of the hard palate in the population involves the need to perform bone and mucosa thickness measurements before palatal micro-implant placement.

Palatal bone thickness for mini-implant insertion in different vertical growth patterns: a systematic review.

The purpose of this systematic review was to identify, evaluate, and provide information about palatal bone thickness in different vertical growth patterns for the placement of orthodontic anchorage devices. We performed a systematic review of the published data in Medline via PubMed, Web of Science, Cochrane Library, and Scopus from January 2000 to August 2022 using eligibility criteria. Data collection analysis and data extraction were performed independently by three reviewers. Sensitivity analyses were performed with the Cochrane risk of bias tool and the ROBINS-I tool was used for non-randomized studies. A total of 343 articles were identified. The inclusion criteria included palatal bone thickness and vertical facial growth. However, both variables were found in 4 studies and only 2 had a control group. The different studies evaluated palatal bone thickness according to sex (male 14.1 mm; female 9.68 mm) and vertical malocclusion (normal 2.2 -12.6 mm; open bite 1.9 -13.2mm) with heterogeneous results. Likewise, the vertical growth pattern with a low angle (9.39 mm) was greater than the normal (8.55 mm) and high angle (7.53 mm). Palatal bone thickness varies according tp different vertical growth patterns, with the greatest thickness being found near the incisive foramen in hypodivergent individuals.

Morphometric Comparison of the Maxillary Alveolar Ridge Profile at Lateral Incisor and Premolar Tooth Regions Using Cone Beam Computed Tomography: A Cross-sectional Comparative Study

Comprehensive pre-surgical evaluation, proper radiographic examination and careful surgical intervention are necessary for long-term success of implants. This study highlights the importance of assessment of morphometric dimensions of alveolar ridge profile at the maxillary lateral incisor and premolar using cone beam computed tomography (CBCT) thereby reducing the complications during the clinical procedures like implant placement, mini-implants in orthodontic anchorage, para-endodontic surgeries.&#x0D; A total of 58 CBCT scans were included in the study and divided into two groups. (group-A, 20-35 years; group-B, 36-50 years). The buccal and palatal thickness of the maxillary alveolar cortical plates were measured at the crest, mid root, mid alveolar housing area, and the apex of the root.&#x0D; In the sample of 58 CBCTs, the cortical plate thickness at the crest of the premolars has a significant increased thickness when compared to the lateral incisor in both the age groups. The thickness of mid alveolar housing point of premolars has significant increased thickness than the lateral incisors of age group-B.&#x0D; In this study, the recommendations based on the results were beneficial in providing information regarding the buccal and palatal bone thickness at the maxillary lateral incisor and premolar tooth regions in 21-35 years and 36-50 years age groups thereby preventing complications that occur while undergoing dental procedures.

Influence of buccal and palatal bone thickness on post-surgical marginal bone changes around implants placed in posterior maxilla: a multi-centre prospective study

BackgroundNumerous clinical variables may influence early marginal bone loss (EMBL), including surgical, prosthetic and host-related factors. Among them, bone crest width plays a crucial role: an adequate peri-implant bone envelope has a protective effect against the influence of the aforementioned factors on marginal bone stability. The aim of the present study was to investigate the influence of buccal and palatal bone thickness at the time of implant placement on EMBL during the submerged healing period.MethodsPatients presenting a single edentulism in the upper premolar area and requiring implant-supported rehabilitation were enrolled following inclusion and exclusion criteria. Internal connection implants (Twinfit, Dentaurum, Ispringen, Germany) were inserted after piezoelectric implant site preparation. Mid-facial and mid-palatal thickness and height of the peri-implant bone were measured immediately after implant placement (T0) with a periodontal probe and recorded to the nearest 0.5 mm. After 3 months of submerged healing (T1), implants were uncovered and measurements were repeated with the same protocol. Kruskal-Wallis test for independent samples was used to compare bone changes from T0 to T1. Multivariate linear regression models were built to assess the influence of different variables on buccal and palatal EMBL.ResultsNinety patients (50 females, 40 males, mean age 42.9 ± 15.1 years), treated with the insertion of 90 implants in maxillary premolar area, were included in the final analysis. Mean buccal and palatal bone thickness at T0 were 2.42 ± 0.64 mm and 1.31 ± 0.38 mm, respectively. Mean buccal and palatal bone thickness at T1 were 1.92 ± 0.71 mm and 0.87 ± 0.49 mm, respectively. Changes in both buccal and palatal thickness from T0 to T1 resulted statistically significant (p = 0.000). Changes in vertical bone levels from T0 to T1 resulted not significant both on buccal (mean vertical resorption 0.04 ± 0.14 mm; p = 0.479) and palatal side (mean vertical resorption 0.03 ± 0.11 mm; p = 0.737). Multivariate linear regression analysis showed a significant negative correlation between vertical bone resorption and bone thickness at T0 on both buccal and palatal side.ConclusionThe present findings suggest that a bone envelope > 2 mm on the buccal side and > 1 mm on the palatal side may effectively prevent peri-implant vertical bone resorption following surgical trauma.Trial RegistrationThe present study was retrospectively recorded in a public register of clinical trials (www.clinicaltrials.gov - NCT05632172) on 30/11/2022.

Do the miniscrews of the prefabricated systems for the “appliance first” protocol of miniscrew-assisted rapid palatal expansion have lengths that meet the palatal thickness of patients?

In the "appliance first" protocol of miniscrew-assisted rapid palatal expansion, the prefabricated shape of the expanders limits the potential locations for miniscrew placement. Considering the influence of palatal thickness on the selection of the optimal length of miniscrews, this study aimed to evaluate the thickness of both bone and mucosa of the palate of patients aged 6-65 years and suggest optimal lengths of miniscrews for this approach. Two hundred and eighty-two cone-beam computed tomography of patients of both sexes were divided into 3 groups according to age. The thicknesses of bone and mucosa were measured in the anterior and posterior regions of the palate. Males showed a greater thickness of palatal bone than females. The thickness of both bone and mucosa was greater in the anterior region of the palate. The young patients showed greater bone thickness than adults and mature adults. The mature adults showed thinner bone thickness in the posterior region of the palate and greater mucosal thickness along the palate than young patients and adults. Development of miniscrews with longer thread lengths is necessary. Miniscrews with a 3-mm thread length would prevent excessive extravasation in the posterior region of the palate. The thickness of both bone and mucosa of the palate is variable and influenced by sex and age. Manufacturing additional miniscrews with different lengths of thread is suggested to achieve bicortical anchorage in patients undergoing the "appliance first" protocol of miniscrew-assisted rapid palatal expansion.

Cone Beam Computed Tomography (CBCT) Evaluation of Alveolar Bone Thickness and Root Angulation in Anterior Maxilla for Planning Immediate Implant Placement.

This retrospective study aimed to measure the labial, palatal, mesial, and distal bone thickness around maxillary central and lateral incisors and canines and height from crest to apex, using cone beam computed tomography (CBCT) images and compare the results based on gender. The second objective of the study was to measure root angulation on CBCT images and its relation with the labial cortical thicknesses. Material and Methods:After the Institutional Review Board (IRB) approval, a total of 140 CBCT volumes were included in this study according to the set criteria. On each scan, right-side maxillary central, lateral incisors, and canine were selected for the measurements. All the measurements were done at three levels at the alveolar crest (L1), mid-root (L2), and apical region (L3) for each tooth. Results:The Student's t-test was performed to compare the result of buccal, palatal, mesial, and distal bone thickness,angulation, and height of all subjects. Buccal alveolar bone thickness was minimum at the mid-root region, and the palatal bone thickness was minimum at the crestal region. The mesial bone thickness was minimum at the mid-root level, and distalbone thickness was minimum at the crest level. The available bone height was maximum at the lateral incisor and equal for the central incisor and canine. The canine was the most angulated tooth. Cone beam computed tomography is a reliable imaging modality to evaluate pre-surgical immediate implant sites and measurealveolar bone thickness. The canine was the most angulated tooth with more buccal alveolar bone thickness.

Immediate dentoskeletal and periodontal effects of miniscrew-assisted rapid palatal expansion: Comparison between young vs middle-aged adults

This study aimed to compare the dentoskeletal and periodontal changes after miniscrew-assisted rapid palatal expansion (MARPE) in patients aged 18-29 and 30-45 years. The sample comprised 28 subjects with transverse maxillary discrepancy successfully treated with MARPE. The young adult (YA) group comprised 14 subjects (mean age, 22.8 years; 3 male, 11 female). The middle adult (MA) group comprised 14 subjects (mean age, 36.8 years; 6 male, 8 female). All patients were treated with a 4-miniscrew MARPE expander. The activation protocol was one quarter turn twice a day until the midline diastema opening, followed by one quarter turn a day until overcorrection. Cone-beam computed tomography (CBCT) scans taken before and immediately after the expansion was analyzed using OnDemand3D Dental software. Using CBCT coronal images, transversal dentoskeletal and periodontal variables were measured in the preexpansion and postexpansion. Intergroup comparisons of expansion changes were performed using t and Mann-Whitney tests (P<0.05). Groups were compatible at preexpansion for most CBCT measurements. A success rate of midpalatal suture opening of 100% and 81% was observed for YA and MA groups, respectively. No intergroup differences were found for the maxillary and dental arch widths increases. The buccal tip of anchorage teeth was observed similarly in both groups. The buccal bone thickness of posterior teeth decreased, and the palatal bone thickness increased after expansion with no difference between groups. After MARPE, the MA group showed similar dentoskeletal and periodontal changes compared to the YA group.

Bone quality in relation to skeletal maturation in palatal miniscrews insertion sites

This study aimed to investigate the relationship between bone density and quantity at the insertion sites of palatal miniscrews and skeletal maturation-evaluated with the middle phalanx maturation method-in growing patients. Sixty patients were analyzed as having a staged third finger middle phalanx radiograph and a cone-beam computed tomography of the maxilla. On the cone-beam computed tomography, a grid was designed to parallel the midpalatal suture (MPS) and posterior to the nasopalatine foramen, both on the palatal and lower nasal cortical bones. Bone density and thickness were measured at the intersections, and medullary bone density was also calculated. Of patients in MPS stages 1-3, 67.6% showed a mean palatal cortical thickness of<1 mm, whereas in 78.3% of the patients in stages 4 and 5, it was>1 mm. The nasal cortical thickness showed a similar trend (MPS stages 1-3: 62.16%<1 mm; MPS stages 4 and 5: 65.2%>1 mm). There was a significant difference in the density of the palatal cortical bone between MPS stages 1-3 (1272.05 ± 191.13) and stages 4 and 5 (1572.33 ± 274.89) and in nasal cortical density between MPS stages 1-3 (1428.09 ± 198.97) and stages 4 and 5 (1597.97 ± 267.75) (P<0.001). This study revealed a correlation between skeletal maturity and maxillary bone quality. MPS stages 1-3 have lower palatal cortical bone density and thickness but high nasal cortical bone density values. MPS stage 4 and, even more, stage 5 show increasing palatal cortical bone thickness and palatal and nasal cortical bone density values.

Correlation of age and skeletal effects after miniscrew assisted rapid palatal expansion.

To evaluate the skeletal and dentoalveolar effects after miniscrew assisted rapid palatal expansion (MARPE) and their correlation with the age of the patients. Settings and sample population: Sample comprised 19 patients with maxillary atresia and posterior crossbite, treated with MARPE. Cone-beam computed tomographs (CBCT) were evaluated before and after expansion. Three patients were excluded since the midpalatal suture was not opened. Thus, 16 patients (11 female; 5 male) were evaluated, with a mean age of 24.92 years (s.d.=7.60). The time between the installation of MARPE and the second CBCT was, on average, 1.64 months (s.d.=1.12). Linear and angular measurements were performed: bone thickness and level, tooth inclination, transverse dental widths, and nasal base and jugula widths. Comparison was performed with dependent t-test and correlations with Pearson coefficient. MARPE was 84.2% successful. There was significant reduction in the buccal bone thickness of the first molars and an increase in the palatal bone thickness of all teeth. First molars showed significant buccal inclination. All transverse dimensions showed a significant increase. Older patients tended to show a less maxillary transverse skeletal increase. A greater maxillary transverse increase was accompanied by a greater intermolar width increase and also a greater buccal bone loss in the mesiobuccal roots of the maxillary first molars. MARPE corrected the maxillary atresia in adult patients, with significant transverse increases, a slight decrease in buccal bone thickness and buccal inclination of the first molars, combining skeletal and dental effects. Older patients presented less transverse skeletal increases. Key words:Palatal expansion technique, skeletal anchorage, cone-beam computed tomography.

Detailed Correlation between Central Incisor Movement and Alveolar Bone Resorption in Adults with Orthodontic Premolar Extraction Treatment: A Retrospective Cohort CBCT Study.

This study aims to explore the detailed correlation between the movement of maxillary and mandibular central incisors and alveolar bone resorption in adults who had orthodontic premolar extraction treatment. A total of 63 adult patients (mean age, 24.41 years) who received orthodontic treatment with the extraction of four first premolars were included in this study. CBCT images were obtained before and after treatment. Three-dimensional evaluations of the movement of 252 central incisors (126 maxillary and 126 mandibular incisors) and alveolar bone changes were conducted. Four points were used to describe the incisor movement: C (cusp point), R (root apex point), M (mid-point of root neck), and L (labial cementoenamel junction point). The thickness of labial and palatal alveolar bone was assessed at the crestal, mid-root, and apical levels of incisors. The results were analyzed with Spearman's correlation and multilinear regression. Matching the measurements of central incisor movement and alveolar bone resorption, significant correlations could be observed. For maxillary central incisors, the labial alveolar bone resorption at the crestal level was correlated with the movement of Point L (r = 0.290, p &lt; 0.05), and the labial alveolar bone resorption at the apical level was correlated with Point M (r = 0.387, p &lt; 0.05). For mandibular central incisors, the labial alveolar bone resorption at the apical level was correlated with the movement of Point M (r = 0.493, p &lt; 0.05) and R (r = 0.498, p &lt; 0.01); the palatal alveolar bone resorption at the mid-root level with Point M (r = -0.170, p &lt; 0.01); and the palatal alveolar bone resorption at the apical level with Point R (r = 0.177, p &lt; 0.01). This study investigated the concrete correlations between central incisor movement and alveolar bone resorption in adults after orthodontic treatment with premolar extraction. It is potentially helpful for orthodontists to have a relatively accurate prediction of alveolar bone resorption based on the specific movements of central incisors and to reduce the risk of alveolar bone resorption by better adjusting the three-dimensional movement types of incisors.