[Transverse characteristics of normodivergent patients in different sagittal skeletal patterns].

PURPOSE: This study aimed to measure and analyze the transverse indicators of normodivergent patients with different sagittal skeletal malocclusions, to explore the transverse characteristics of different sagittal skeletal malocclusions. METHODS: Lateral cephalograms and CBCT of 90 normodivergent patients with skeletal Class Ⅰ, Ⅱ and Ⅲ in their permanent dentition were collected. Dolphin software was applied to measure the widths of the basal bone, alveolar bone, dental arch and buccolingual inclination angle of the corresponding teeth in the maxillary and mandibular canine, premolar and molar areas. SPSS 22.0 software package was applied for statistical analysis of the data. RESULTS: The widths of the mandibular basal bone in canine, premolar and molar areas of skeletal Class Ⅲ were (27.15±2.74), (39.30±2.82) and (59.97±2.93) mm, respectively. The widths of the mandibular alveolar bone of skeletal Class Ⅲ were (25.38±1.78), (34.51±2.28) and (47.72±2.73) mm, respectively. The dental arch widths of the maxillary premolar and mandibular canine areas of skeletal Class Ⅲ were (48.70±2.35) and (30.69±2.31)mm, respectively. The above data of skeletal Class Ⅲ were significantly larger than those of skeletal Class Ⅰ and Ⅱ(P＜0.01). The dental arch widths of the maxillary canine, maxillary molar and mandibular molar areas of skeletal Class Ⅲ were (38.88±1.90), (59.51±3.40) and (56.01±2.86)mm, respectively, which were significantly larger than those of skeletal Class Ⅱ(P＜0.05). The maxillomandibular width difference of basal bone in the canine, premolar and molar areas of skeletal Class Ⅲ were (4.69±2.84), (2.31±2.39) and (3.27±2.05) mm, respectively, which were significantly less than that of skeletal Class Ⅰ and Ⅱ(P＜0.01). Compared with skeletal Class Ⅰ, the maxillary canines and first molars of skeletal Class Ⅱ had larger lingual inclination level, while the maxillary first premolars and first molars of skeletal Class Ⅲ had larger buccal inclination level, the mandibular canines and the mandibular first premolars of skeletal Class Ⅲ had larger lingual inclination level(P＜0.01). CONCLUSIONS: For normodivergent patients, the width of the mandibular base bone, alveolar bone, and maxillary and mandibular dental arch in skeletal Class Ⅲ is the widest, which is more likely to have width discrepancy in basal bone. In skeletal Class Ⅲ, the maxillary teeth are buccally inclined, and the mandibular teeth are ingually inclined. In skeletal Class Ⅱ, the maxillary teeth are lingually inclined, and the mandibular teeth are compensatory upright.

Development of a correction coefficient for radiographic evaluation of the alveolar bone crest: a pilot study.

OBJECTIVES: To analyze the differences in cusp height on radiographs, establishing proportional relationships between cusp and alveolar bone crest (ABC) measurements. The goal of this study was to develop a correction coefficient by considering this proportion. MATERIALS AND METHODS: Twenty-one artificial teeth, molars and premolars, and bovine ribs were used. Interproximal radiographs were taken with the aid of a positioner. The vertical angles used were: 0°, + 5°, and + 10°, and processed using three spatial resolutions measured in line pairs per mm (lp/mm): 20, 25 and 40. The Perio filter was applied to each image, in addition to the original one. Combinations of angle, resolution, and filter were made. Eighteen images were analyzed by three specialists, resulting in 252 measurements for each evaluator, totaling 756 measurements. RESULTS: The overall variability of the measurements can be explained mainly by the variation in tooth anatomy. The 0° 25 lp/mm Perio filter method was the closest one to the actual clinical scenario for both cusps and ABC. The correction factor managed to explain 71.45% of the errors. CONCLUSIONS: The variation in vertical angulation interferes with cusp and ABC measurements, and the angulation at 0º and spatial resolution of 25 lp/mm showed better results. The use of correction coefficients allowed approaching actual measurement values. CLINICAL RELEVANCE: More accurate ABC height measurements are essential even in radiographic exams that do not meet the standard of excellence because the need to repeat radiographic exams is then eliminated.

Fibrin-konjac glucomannan-black phosphorus hydrogel scaffolds loaded with nasal ectodermal mesenchymal stem cells accelerated alveolar bone regeneration.

BACKGROUND: Effective treatments for the alveolar bone defect remain a major concern in dental therapy. The objectives of this study were to develop a fibrin and konjac glucomannan (KGM) composite hydrogel as scaffolds for the osteogenesis of nasal mucosa-derived ectodermal mesenchymal stem cells (EMSCs) for the regeneration of alveolar bone defect, and to investigate the osteogenesis-accelerating effects of black phosphorus nanoparticles (BPNs) embedded in the hydrogels. METHODS: Primary EMSCs were isolated from rat nasal mucosa and used for the alveolar bone recovery. Fibrin and KGM were prepared in different ratios for osteomimetic hydrogel scaffolds, and the optimal ratio was determined by mechanical properties and biocompatibility analysis. Then, the optimal hydrogels were integrated with BPNs to obtain BPNs/fibrin-KGM hydrogels, and the effects on osteogenic EMSCs in vitro were evaluated. To explore the osteogenesis-enhancing effects of hydrogels in vivo, the BPNs/fibrin-KGM scaffolds combined with EMSCs were implanted to a rat model of alveolar bone defect. Micro-computed tomography (CT), histological examination, real-time quantitative polymerase chain reaction (RT-qPCR) and western blot were conducted to evaluate the bone morphology and expression of osteogenesis-related genes of the bone regeneration. RESULTS: The addition of KGM improved the mechanical properties and biodegradation characteristics of the fibrin hydrogels. In vitro, the BPNs-containing compound hydrogel was proved to be biocompatible and capable of enhancing the osteogenesis of EMSCs by upregulating the mineralization and the activity of alkaline phosphatase. In vivo, the micro-CT analysis and histological evaluation demonstrated that rats implanted EMSCs-BPNs/fibrin-KGM hydrogels exhibited the best bone reconstruction. And compared to the model group, the expression of osteogenesis genes including osteopontin (Opn, p < 0.0001), osteocalcin (Ocn, p < 0.0001), type collagen (Col , p < 0.0001), bone morphogenetic protein-2 (Bmp2, p < 0.0001), Smad1 (p = 0.0006), and runt-related transcription factor 2 (Runx2, p < 0.0001) were all significantly upregulated. CONCLUSIONS: EMSCs/BPNs-containing fibrin-KGM hydrogels accelerated the recovery of the alveolar bone defect in rats by effectively up-regulating the expression of osteogenesis-related genes, promoting the formation and mineralisation of bone matrix.

Competence of allogenic demineralized tooth matrix in socket seal surgery for alveolar ridge preservation: a randomized control clinical trial.

OBJECTIVES: To assess and compare the clinical, radiological, and histological outcomes of socket seal surgery between two protocols: deproteinized demineralized tooth matrix (dpDTM) and freeze-dried bone allograft (FDBA) each covered with a free gingival graft. MATERIALS AND METHODS: Twenty extraction sockets in the anterior or premolar region were randomly allocated to either the dpDTM or FDBA protocol (n = 10 per group). Measurements of the alveolar ridge changes were obtained using an intraoral scanner and cone-beam computed tomography at 3 months post-operation. Three-month post surgery, the dental implant was installed (n = 5 per group), bone biopsies were obtained for histomorphometrical and micro-computed tomography analyses. Implant stability quotients (ISQs) were determined and compared at 3 months post-implant. RESULTS: Lower significant reductions in buccal alveolar ridge height and hard tissue volume were observed in dpDTM group compared to FDBA group at 3 months (0.25 ± 0.35 mm vs. 1.60 ± 0.66 mm [p = .000] and 9.64 ± 15.39% mm3 vs. 31.45 ± 18.11% mm3 [p = .010], respectively). At the same time, lower soft tissue volume reduction was detected in the dpDTM group compared to FDBA group (4.21 ± 5.25% mm3 vs. 5.25 ± 5.79% mm3). No statistically significant difference in the percentage of mineralized tissue formation was found between dpDTM group (53.39 ± 11.16%) and FDBA group (49.90 ± 3.27%). Even though the ISQ in the dpDTM group showed a higher value than the FDBA group at 3 months post-implant, the results were without statistical significance. CONCLUSIONS: Alveolar ridge preservation using dpDTM is an efficacious procedure for providing the conditions for the development of functional and esthetic implants.

Variations in the alveolar bone morphology in maxillary molar area: a retrospective CBCT study.

BACKGROUND: This study quantitatively analyzed the anatomic structure of the alveolar bone in the maxillary molar region at three potential locations for Temporary Anchorage Device (TAD) placement. Additionally, the study compared the variability in this region across different age groups, sagittal skeletal patterns, vertical facial types, and sexes. METHODS: In this retrospective cone-beam computed tomography study, the buccal alveolar bone was analyzed in the posterior molar area of 200 patients, the measurement items include buccal alveolar bone height, alveolar bone thickness, interradicular distance, and maxillary retromolar space. RESULTS: Buccal alveolar height was greatest in the U56 region. The interradicular space was largest in the U56 region and increased from the alveolar crest to the sinus floor. Buccal alveolar bone thickness was highest in the U67 region and generally increased from the alveolar crest to the sinus floor. The maxillary retromolar space gradually increased from the alveolar crest to the root apex. CONCLUSIONS: TADs are safest when placed in the buccal area between the maxillary second premolar and the first molar, particularly at the 9 mm plane. The U67 region is the optimal safe zone for TAD placement for maxillary dentition distalization. TADs placement in adolescents can be challenging. Maxillary third molar extraction can be considered for maxillary dentition distalization.

ANATOMICAL VARIABILITY OF THE ALVEOLAR PROCESS OF THE MAXILLA BASED ON MULTISLICE COMPUTED TOMOGRAPHY DATA.

Modern research methods, widely implemented in routine medical practice, open new horizons for the study of anatomical structures. The maxilla is one of the regions of the human skull that shows significant variability with age and gender. This is due to the peculiarities of tooth eruption and age-related changes in the periodontium and adjacent structures, which undoubtedly affect the structure of the alveolar process, sometimes drastically altering it over time. The aim of our study was to determine the anatomical variability of the alveolar process of the maxilla based on multislice computed tomography data. MATERIAL AND METHODS: The research was conducted based on the results of 400 spiral computed tomography scans of males and females aged 18 to 95 years with detection of the anatomical variability of the alveolar process. RESULTS: The average height of the alveolar process was 14.3±0.99x10^-3 m. The thickness of the wall also showed considerable variability. It was maximal in the middle part and minimal in the lateral part of the wall, measuring 1.905±0.021x10^-3 m and 1.15±0.011x10^-3 m, respectively. CONCLUSIONS: We determined its thickness, density, and identified teeth whose roots are connected to the maxillary sinus. The thickness of the alveolar process correlates with the volume of the sinus, showing a strong negative correlation (r=-0.92). Thus, with larger sinus sizes, the alveolar process has a smaller thickness. According to calculations, there is a correlation between the upper facial index and the size of the alveolar process (r=0.64). In dolichocephalic individuals, the longitudinal size is greater than in brachycephalic individuals, where the transverse size of the alveolar process prevails.

A multi-centric, single-blinded, randomized, parallel-group study to evaluate the effectiveness of nasoalveolar moulding treatment in non-syndromic patients with complete unilateral cleft lip, alveolus and palate (NAMUC study): a study protocol for a randomized controlled trial.

BACKGROUND: Cleft lip and palate (CLP) are among the most common congenital anomaly that affects up to 33,000 newborns in India every year. Nasoalveolar moulding (NAM) is a non-surgical treatment performed between 0 and 6 months of age to reduce the cleft and improve nasal aesthetics prior to lip surgery. The NAM treatment has been a controversial treatment option with 51% of the cleft teams in Europe, 37% of teams in the USA and 25 of cleft teams in India adopting this methodology. This treatment adds to the already existing high burden of care for these patients. Furthermore, the supporting evidence for this technique is limited with no high-quality long-term clinical trials available on the effectiveness of this treatment. METHOD: The NAMUC study is an investigator-initiated, multi-centre, single-blinded randomized controlled trial with a parallel group design. The study will compare the effectiveness of NAM treatment provided prior to lip surgery against the no-treatment control group in 274 patients with non-syndromic unilateral complete cleft lip and palate. The primary endpoint of the trial is the nasolabial aesthetics measured using the Asher McDade index at 5 years of age. The secondary outcomes include dentofacial development, speech, hearing, cost-effectiveness, quality of life, patient perception, feeding and intangible benefits. Randomization will be carried out via central online system and stratified based on cleft width, birth weight and clinical trial site. DISCUSSION: We expect the results from this study on the effectiveness of treatment with NAM appliance in the long term along with the cost-effectiveness evaluation can eliminate the dilemma and differences in clinical care across the globe. TRIAL REGISTRATION: ClinicalTrials.gov CTRI/2022/11/047426 (Clinical Trials Registry India). Registered on 18 November 2022. The first patient was recruited on 11 December 2022. CTR India does not pick up on Google search with just the trial number. The following steps have to be carried out to pick up. How to search: ( https://ctri.nic.in/Clinicaltrials/advsearch.php -use the search boxes by entering the following details: Interventional trial > November 2022 > NAMUC).

[Application of autogenous block bone graft in the reconstruction of severe alveolar crest defect].

Patients with severe alveolar ridge defects cannot be directly implanted and repaired, which seriously affects their quality of life. Onlay bone grafting is the main solution for severe alveolar ridge bone defect reconstruction, among which autogenous block bone grafting is the most widely used and is also the focus of clinical research on bone tissue reconstruction. This article expounds the characteristics and basic principles of autogenous bone block grafting, and comprehensively analyzes the selection of autogenous bone donor site, the principles of surgical operation, and the progress of bone graft techniques. In order to help surgeons make correct clinical decisions, increase the predictability of surgical effects, and improve the level of clinical diagnosis and treatment.

[Atorvastatin promotes the healing of alveolar bone defect in rats and its effect on Wnt/ß-catenin signaling pathway].

PURPOSE: To investigate the therapeutic effect of atorvastatin on alveolar bone defect model in rats, and to observe the effect of atorvastatin on Wnt/ß-catenin. METHODS: Thirty rats were randomly divided into normal group (group N), model group (group M) and atorvastatin administration group (group ATV). Except group N, bone defects were made in other rats' alveolar bone to construct alveolar bone defect model. After successful modeling, 20 mg/kg atorvastatin suspension was administered by gavage in group ATV, and the same amount of sodium carboxymethyl cellulose solution was administered by gavage in group N and group M for twenty-one days. After the last administration, tail vein blood was collected to detect the concentrations of serum osteoprotegerin (OPG), alkaline phosphatase (ALP) and osteocalcin (BPG). H-E staining was used to observe the pathological changes of maxillary defect area, and lane Sandhu score was performed. Tartrate resistant acid phosphatase(TRAP) staining was used to detect the number of osteoclasts in the defect area. Real time fluorescence quantitative PCR(RT-qPCR) and Western blot(WB) were used to detect Wnt, ß-catenin and Runx2 mRNA protein expression. Statistical analysis was performed with SPSS 23.0 software package. RESULTS: Compared with group N, the concentrations of OPG, ALP, BGP and Lane Sandhu score in group M decreased, and the number of osteoclasts increased. Compared with group M, the concentrations of OPG, ALP and BGP and lane Sandhu score in group ATV increased, and the number of osteoclasts decreased. After H-E staining, the amount of bone formation in maxillary defect area in group N was more,there was fewer bone tissues in the defect area in group M, the amount of bone tissues in the defect area increased in group ATV. Compared with group N, Wnt, ß-catenin and Runx2 mRNA protein decreased. Compared with group M, Wnt, ß-catenin and Runx2 mRNA protein expression increased. CONCLUSIONS: Atorvastatin can promote the healing of alveolar bone defect and accelerate bone reconstruction in rat models. This effect may be related to the activation of Wnt/ß-catenin signaling pathway.

Comparative evaluation of transverse width indices for diagnosing maxillary transverse deficiency.

OBJECTIVES: This study aimed to compare and evaluate different transverse width indices for diagnosing maxillary transverse deficiency (MTD), a common malocclusion characterized by uncoordinated dental arches, crossbites, and tooth crowding. MATERIALS AND METHODS: Sixty patients aged 7-12 years were included in the study, with 20 patients diagnosed with MTD and 40 normal controls. Transverse width indices, including maxillary width at the buccal alveolar crest and lingual midroot level, as well as at the jugal process width, were measured. Differences between these indices and their corresponding mandibular indices were used as standardized transverse width indices. The reference range of these indices was determined and evaluated. Receiver operating characteristic (ROC) analysis was performed to evaluate their diagnostic ability. RESULTS: The transverse width indices and standardized transverse width indices of the MTD group were significantly smaller than those of the control group, except for the jugal process width. The evaluation of the reference range and ROC analysis revealed that the difference of the maxillomandibular width at buccal alveolar crest was the most accurate diagnostic method. CONCLUSIONS: The jugal point analysis method may not be suitable for diagnosing MTD. Instead, measuring the difference in maxillomandibular width at the buccal alveolar crest proves to be a more reliable and accurate diagnostic method for MTD.

Associations between the keratinized mucosa width and the underlying alveolar bone dimensions at partial edentulous molar sites: a retrospective cross-sectional study.

BACKGROUND: The assessment of hard and soft tissue at edentulous sites is important for subsequent implant treatment design. The aim of the present study was to explore the associations between the keratinized mucosa width (KMW) and the underlying alveolar bone dimensions at partial edentulous molar sites. METHODS: In this retrospective study, a total of 110 patients with at least one missing molar were selected. The buccal KMW of the edentulous molar sites was evaluated. Cone-beam computed tomography scans were collected, and the height discrepancy between the alveolar crest and the buccal bone plate (HC-B) as well as the alveolar bone height (ABH) were measured. The KMW was compared among the HC-B and ABH groups at both maxillary and mandibular sites. Linear regression and generalized estimation equations (GEEs) were used to explore the associations between the KMW and alveolar bone dimensions at α = 0.05. RESULTS: Among the 110 patients, 158 edentulous molar sites were analyzed. The average HC-B and ABH were significantly lower at the maxillary sites (1.26 ± 1.62 mm, 11.62 ± 3.94 mm) than at the mandibular sites (3.67 ± 2.85 mm, 14.91 ± 3.01 mm, p < 0.001). The KMW was significantly lower at sites with HC-B > 2 mm than at sites with HC-B ≤ 2 mm both in the maxilla and mandible (p < 0.001). No significant differences were found between the KMW at sites with ABH < 10 mm and sites with ABH ≥ 10 mm (p > 0.05). Linear regression and GEEs analyses revealed that the HC-B was significantly associated with the KMW (B = -0.339, p < 0.001), while the association between the KMW and the ABH was not statistically significant (B = -0.046, p = 0.352). CONCLUSIONS: The buccal KMW at edentulous molar sites was significantly associated with the HC-B. Alveolar ridges presenting with a sloped configuration were more prone to possess a narrower band of keratinized mucosa. Both hard and soft tissue augmentation should be considered for implant treatment at these sites. The correlations of dynamic changes between the KMW and alveolar bone dimensions after tooth extraction should be further investigated.

Efficacy of Platelet-Rich Fibrin in Preserving Alveolar Ridge Volume and Reducing Postoperative Pain in Site Preservation of Post-Extracted Sockets.

Background and Objectives: In socket preservation, the goal is to minimize bone resorption after tooth extraction to maintain the volume and contour of the alveolar ridge. The use of PRF in post extraction sites may reduce ridge resorption by encouraging the growth of new bone and acting as a scaffold for tissue. In addition, PRF may enhance healing and minimize postoperative pain. The aim of this study was to evaluate the effectiveness of platelet-rich fibrin (PRF) in maintaining the ridges' dimensions at the extraction site, in the maxilla and mandible, as well as its impact on post-extraction discomfort. Methods: The study was conducted on 60 patients presenting for extraction of posterior teeth and was randomly divided into three groups: group I PRF (n = 20), group II PRF + collagen (n = 20), and group III control (n = 20). Sockets were filled with PRF (group I) and PRF + collagen (group II). At baseline and follow-up after 3 months, CBCT was used to assess the bone dimensions. The postoperative pain evaluations were performed at 24 h, 3 days, and 7 days after the tooth extraction. The pain rate was evaluated using a numerical rating scale from the British Pain Society. Results: The study examined the effects of platelet-rich fibrin (PRF) and PRF combined with collagen on the height and width of the ridges, as well as the pain experienced by the patients following alveolar ridge preservation surgery. ANOVA and t-tests were used to evaluate and compare the ridge dimensions. Comparing the results to the control group, there were no significant differences in the height or width of the ridges. However, both the PRF and PRF + Collaplug® treatments effectively reduced the short-term postoperative pain. Conclusions: The study findings suggest that platelet-rich fibrin (PRF) and PRF combined with collagen do not exert significant effects on ridge width and height compared to the standard treatment following alveolar ridge preservation. However, it is noteworthy that both the PRF and PRF + collagen treatments demonstrated efficacy in reducing postoperative pain in the short term, offering a potential advantage over standard treatment protocols.

Prevention of bone dehiscence associated with orthodontic tooth movement by prophylactic injection of bone anabolic agents in mice.

Although bone dehiscence may occur during orthodontic tooth movement into the narrow alveolar ridge, a non-invasive prevention method is yet to be fully established. We show for the first time prevention of bone dehiscence associated with orthodontic tooth movement by prophylactic injection of bone anabolic agents in mice. In this study, we established a bone dehiscence mouse model by applying force application and used the granular type of scaffold materials encapsulated with bone morphogenetic protein (BMP)-2 and OP3-4, the receptor activator of NF-κB ligand (RANKL)-binding peptide, for the prophylactic injection to the alveolar bone. In vivo micro-computed tomography revealed bone dehiscence with decreased buccal alveolar bone thickness and height after force application, whereas no bone dehiscence was observed with the prophylactic injection after force application, and alveolar bone thickness and height were kept at similar levels as those in the control group. Bone histomorphometry analyses revealed that both bone formation and resorption parameters were significantly higher in the injection with force application group than in the force application without the prophylactic injection group. These findings suggest that the prophylactic local delivery of bone anabolic reagents can prevent bone dehiscence with increased bone remodelling activity.

Pain-related analysis on a resorbed ridge with various denture occlusal schemes using finite element method.

Resorbed alveolar ridges, particularly in the lower jaw, have a small denture supporting area, which may cause the stress distribution of mastication load to exceed the pressure-pain threshold (PPT) and induce pain in the mucosa or potentially worsen the ridge resorption. Thus, choosing the ideal occlusal scheme among bilateral balanced (BBO), lingualized (LO), and monoplane (MO) for such conditions becomes crucial. The experiment was conducted using the finite element method on a modeling of a resorbed alveolar ridge in the lower jaw with three dentures placed on top, each of which was given different loading points according to the tooth arrangement of BBO, LO, and MO. The axial load was 100 N, and the resultant oblique loads on BBO and LO were 119 N and 106 N, respectively. The von Mises stresses for BBO, LO, and MO were observed in nine denture-supporting areas, and the results showed that the axial load did not produce stresses that exceeded the PPT value (0.64925 MPa) for BBO, LO, and MO with the highest value on area H, 0.43229 MPa, 0.39715 MPa, and 0.31576 MPa, respectively. However, the oblique load direction showed that the BBO had more areas (area E 0.80778 MPa and area H 0.76256 MPa) that exceeded the PPT than LO (area E 0.64394 MPa). The lingualized occlusal scheme is ideal for patients with resorbed alveolar ridge conditions, especially in terms of limiting interferences when the denture is functioning while maintaining comfort but still providing good masticatory performance and satisfactory esthetics.

Effect of force direction and impaction angulation during dilaceration impacted central incisor traction: a finite element analysis.

BACKGROUND: The effects of traction forces at different angles on impacted central incisors(ICI)with varying inverted angles (IA) may be different. The objective of this study was to analyze the biomechanical effects of different force directions (FD) on developmentally inverted ICI with multi-angle variations and to offer insights and guidance for the treatment of inverted ICI. METHODS: Three-dimensional finite element method was employed to simulate clinical scenarios of inverted ICI traction. As such, 0.2 N of force (direction: antero-superior angles of 90°, 100°, 110°, 120°, and 130° relative to the long axis of the inverted ICI crown) was applied to the inverted ICI with inverse angles (IA) of 40°, 30°, 20°, 10° and 0°. Inverted ICI apical displacement and Von Mises stress on periodontal ligament (PDL) and alveolar bone were compared. RESULTS: IA and FD showed minimal influence on the stress distribution in the PDL, as higher stresses were concentrated in the apical region. The higher stresses in the alveolar bone are focused on the cervical and apical regions of the tooth. In particular, IA exerts a more significant impact on stress distribution in the alveolar bone than FD. The influence of IA on the apical displacement of inverted ICI is larger than that of FD. CONCLUSIONS: To promote the health of the root and periodontal tissues, it is recommended to use an angle of 100°-110° relative to the long axis of the ICI crown when dealing with a large IA (> 20°) developmentally inverted ICI. Conversely, an angle of 110°-120° can be used.

Alveolar Ridge Preservation With Fibro-Gide or Connective Tissue Graft: A Randomized Controlled Trial of Soft and Hard Tissue Changes.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of a novel biomaterial (FG) for alveolar ridge preservation compared to CTG in terms of soft tissue thickness and bone dimensional changes. MATERIALS AND METHODS: A randomized clinical trial was conducted on 30 patients who required extraction of 30 hopeless mandibular posterior teeth. All patients went through atraumatic tooth extraction, and then, they were randomly allocated to either a CTG, an FG, or a spontaneous healing (SH) group (1:1:1). All patients received a dental implant placed 6 months postoperatively. The soft tissue thickness and bone dimensional changes were measured before and 6 months after the procedure. RESULTS: The study's analysis revealed statistically significant differences in buccal gingival thickness and dimensional bone changes across the three examined groups after 6 months (p < 0.05). The SH group had lower gingival thickness (1.31 ± 0.65 mm) and higher vertical resorption (-1.46 ± 1.67 mm at the buccal aspect) compared with the CTG and FG groups. The CTG and FG groups had similar gingival thickness (2.42 ± 0.70 and 3.00 ± 0.71 mm, respectively) and bone width reduction (+0.86 ± 2.31 and +0.93 ± 2.38 mm, respectively), whereas the CTG group had lower vertical bone loss (-0.30 ± 1.09 mm at the buccal aspect) than the FG group (-0.47 ± 2.30 mm at the buccal aspect). CONCLUSION: FG and CTG demonstrate equivalent soft tissue thickness and comparable horizontal bone dimension outcomes in ARP.

Age-related alveolar bone maladaptation in adult orthodontics: finding new ways out.

Compared with teenage patients, adult patients generally show a slower rate of tooth movement and more pronounced alveolar bone loss during orthodontic treatment, indicating the maladaptation of alveolar bone homeostasis under orthodontic force. However, this phenomenon is not well-elucidated to date, leading to increased treatment difficulties and unsatisfactory treatment outcomes in adult orthodontics. Aiming to provide a comprehensive knowledge and further inspire insightful understanding towards this issue, this review summarizes the current evidence and underlying mechanisms. The age-related abatements in mechanosensing and mechanotransduction in adult cells and periodontal tissue may contribute to retarded and unbalanced bone metabolism, thus hindering alveolar bone reconstruction during orthodontic treatment. To this end, periodontal surgery, physical and chemical cues are being developed to reactivate or rejuvenate the aging periodontium and restore the dynamic equilibrium of orthodontic-mediated alveolar bone metabolism. We anticipate that this review will present a general overview of the role that aging plays in orthodontic alveolar bone metabolism and shed new light on the prospective ways out of the impasse.

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.

Influence of mucosal tissue height on implant crestal bone: A 10-year follow-up of a controlled clinical trial.

OBJECTIVE: To evaluate the 10-year influence of soft tissue height (STH) on crestal bone level changes (CBC) in bone-level implants with non-matching internal conical connections. MATERIAL & METHODS: From the initial 97 patients, 59 (19 men, 40 women, age 55.86 ± 9.5 years) returned for the recall visit. Based on baseline STH, they were categorized into T1 (thin STH ≤2 mm, n = 33), T2 (thin STH augmented with allogenic tissue matrix (ATM), n = 32), and C (thick STH >2 mm, n = 32). Implants were placed in the posterior mandible using a one-stage approach and received single screw-retained restorations. Clinical (PPD, BOP, PI) and radiographic examinations were conducted after 10 years, with CBC calculated mesial and distal to each implant. RESULTS: After 10 years, implants in surgically thickened (T2) or naturally thick STH (C) showed bone gains of 0.57 ± 0.55 mm and 0.56 ± 0.40 mm, respectively (p < 0.0001) shifting from an initial CBC of -0.21 ± 0.33 mm to 0.36 ± 0.29 mm in the thick STH group and -0.2 ± 0.35 mm to 0.37 ± 0.29 mm in the surgically thickened STH group. Implants in naturally thin STH yielded a non-significant trend of bone loss (-0.12 ± 0.41 mm; p > 0.05). CONCLUSIONS: Implants in thin STH (≤2 mm) exhibited greater CBC over the study period. Significant bone gains were observed in thick STH cases, indicating that naturally thick STH or STH augmentation with ATM may contribute to maintain CBC in long-term around implants. CLINICAL SIGNIFICANCE: This is the first long-term follow-up study suggesting that adequate soft tissue height around implants helps maintain stable peri­implant bone levels. While tissue thickness plays a key role, other factors also interact with peri­implant tissue height to sustain crestal bone stability over time.

Effect of supracrestal tissue height on marginal bone level changes at platform-switching dental implants placed crestally and subcrestally: A randomized clinical-trial.

OBJECTIVES: The presence of insufficient peri-implant supracrestal tissue height (STH) may increase marginal bone resorption. This study aims to evaluate the effect of STH on marginal bone level changes (ΔMBC) in platform-switching posterior implants placed crestally and subcrestally. METHODS: A total of 80 implants were included in this study. There were two main groups in the study; STH≤2 mm (A) and STH> 2 mm (B) and four subgroups according to the implant placement level, crestally (I) and subcrestally (II): A-I, A-II, B-I, and B-II. Intraoperatively, STH and placement depths of implants were measured from mesial and distal aspects. The mesial and distal peri-implant marginal bone levels were measured on periapical radiographs at immediately (T0), 6 months (T1), 9 months (T2), and 12 months (T3) after functional loading, and the difference between the marginal bone levels was calculated as the ΔMBC. RESULTS: Statistically significantly more mesial ΔMBC was detected in the A-I than in the B-I at the time of T0-T1. In the group with STH greater than 2 mm, the difference in ΔMBC between the crestally and subcrestally placements was not statistically significant. CONCLUSIONS: This study was found that STH is effective at protecting the marginal bone in the early period, and in cases where the STH is insufficient, subcrestally placement may increase long-term implant success by preventing marginal bone loss from occurring beyond the implant shoulder. The clinical trial number is NCT05595746. CLINICAL SIGNIFICANCE: In this study, it was demonstrated that an STH greater than 2 mm is important for marginal bone stabilization, regardless of crestal and subcrestal levels, and that subcrestally placement is beneficial in cases of insufficient STH.