Alveolar Bone Height Research Articles

Clinical observation of Porcine Collagen Membrane + artificial Bovine Bone Granules Guided tissue regeneration combined with Autologous CGF in the treatment of severe periodontitis bone defect.

To investigate and analyze the clinical observation of porcine collagen membrane + artificial bovine bone granules guided tissue regeneration (GTR) combined with autologous concentration of growth factors (CGF) in the treatment of severe periodontitis bone defect. A total of 94 patients with severe periodontitis bone defects admitted to Shanxi Bethune Hospital from January 2019 to January 2022 were included. They were divided into two groups by simple randomization method. Patients in the control group were treated with porcine collagen membrane + artificial bovine bone granules GTR, while those in the observation group were treated with autologous CGF on the basis of the control group. Before and after treatment, periodontal clinical indicators [sulcus bleeding index (SBI), gingival retreat index (GR), probing depth (PD), clinical attachment loss (CAL), alveolar bone height (AH)] and bone resorption markers [Osteoprotegerin (OPG), bone gla protein (BGP), Type-1 collagen N-terminal peptide (NTX)] were compared between the two groups, and the incidence of postoperative complications in the two groups was recorded. The total efficacy of observation group was significantly higher than that of control group (p<0.05). Three months after surgery, the observation group had lower levels of SBI, PD, CAL and NTX while higher levels of GR, AH, OPG and BGP than the control group (p<0.05). There was no significant difference in complication rate between the two groups (p>0.05). Porcine collagen membrane + artificial bovine bone granules GTR combined with autologous CGF boasts various benefits in the treatment of severe periodontitis bone defects, such as improvement of clinical outcomes, amelioration of periodontal tissue and inhibition of bone resorption.

Cone Beam Computed Tomography Analysis of Posterior-Superior Alveolar Canal from a Fixed Reference Point: Implications for Sinus Floor Elevation Procedure through Lateral Approach.

Sinus floor elevation is commonly done in the maxillary posterior region prior to dental implant placement. This study primarily aimed at assessing the location of the posterior superior alveolar artery (PSAA) canal on cone beam computed tomography (CBCT) scans and its relation to the alveolar ridge and maxillary sinus from a fixed reference point. A total of 226 edentulous maxillary molar sites were included in this retrospective analysis. The distance from the PSAA to the sinus floor (SF), alveolar crest (AC) and a fixed reference point, that is, the roof of sinus (RS) were measured. The alveolar bone height (ABH), thickness of the crestal keratinized mucosa (CKM) and thickness of Schneiderian membrane (SM) were also evaluated. 54 sites (23.89%) were excluded from the study. The SF, AC, RS and ABH values averaged at 11.91mm ± 3.63mm, 16.05mm ± 3.96mm, 25.32mm ± 7.13mm and 4.93mm ± 4.27mm respectively. SF and AC was higher in second molar than first molar region (p < 0.001), but RS did not show significant difference (p = 0.85). CKM and SM averaged at 2.02mm ± 0.68mm and 1.31mm ± 0.81mm respectively. The PSAA can be visualized in CBCT scans with a prevalence of 76.11% and may not be detected when adherent to the sinus membrane. This study stresses on the need for a CBCT, prior to sinus surgeries through lateral approach, to assess the PSAA.

Dentine grafts in socket preservation: An overview

During management of carious teeth, root stumps, fractured roots and unsalvageable teeth, extractions become inescapable. Healing post-extraction is characterized by changes that results in bone formation in the socket internally and changes related to width and height of alveolar ridge externally. The maintenance of height and width of alveolar bone or regeneration of alveolar bone is necessary to provide good support to the prosthesis, conservation of adjacent tooth structure and also for superior and satisfactory aesthetic outcome. A broadly documented approach is the preservation of bone walls by use of bone substitute (bone graft) in the extraction socket, where guided-bone regeneration may be required. Different varieties of bone grafts like autogenous bone grafts, allografts, alloplasts and xenograft may be used. Various factors like donor site morbidity, restricted availability and cost are the limitations of various bone substitutes. A new autogenous bone substitute that is being studied is the extract of patient’s own extracted tooth without need for a secondary bone harvesting site. Tooth-derived mineralized dentin matrix exhibits composition similar to the bone and is a viable option for alveolar bone augmentation immediately after dental extraction. The aim of this review is to analyze the role and efficacy of dentine grafts in preservation of post-extraction sockets. Autogenous dentine graft when used in socket preservation procedures showed many benefits for both patients and the clinicians by excluding donor site morbidity, limited availability and associated cost issues with a better quality of newly substituted bone and minimal amount of residual graft. Future controlled trials are suggested to monitor various tissue changes along with histological studies to provide substantial evidence of its regenerative potential.

CYLD inhibits osteoclastogenesis to ameliorate alveolar bone loss in mice with periodontitis.

Periodontitis is a chronic immune inflammatory disease that can lead to the destruction and loss of the tooth-supporting apparatus. During this process, the balance between bone absorption mediated by osteoclasts and bone formation mediated by osteoblasts is damaged. Consistent with previous studies, we observed that depletion of cylindromatosis (CYLD) resulted in an osteoporotic bone phenotype. However, the effect of CYLD deficiency on periodontitis is undetermined. Here, we investigated whether CYLD affects periodontal tissue homeostasis in experimental periodontitis in Cyld knockout (KO) mice, and we explored the underlying mechanisms. Interestingly, we discovered significant alveolar bone density loss and severely reduced alveolar bone height in Cyld KO mice with experimentally induced periodontitis. We observed increased osteoclast number and activity in both the femurs and alveolar bones, accompanied by the downregulation of osteogenesis genes and upregulation of osteoclastogenesis genes of alveolar bones in ligatured Cyld KO mice. Taken together, our findings demonstrate that the deletion of CYLD in mice plays a vital role in the pathogenesis of periodontal bone loss and suggest that CYLD might exert an ameliorative effect on periodontal inflammatory responses.

Alveolar bone height changes in the anterior tooth region before and after orthodontic treatment for Angle's Class II division 1 malocclusion and related factors.

The aim of this study was to observe the alveolar bone height changes in the anterior tooth region after orthodontic treatment for Angle's Class II division 1 malocclusion. Ninety-three patients treated from January 2015 to December 2019 were retrospectively analyzed, of whom 48 received tooth extraction and 45 did not. After orthodontic treatment, the alveolar bone heights in the anterior tooth regions of tooth extraction and non-extraction groups decreased by 67.31% and 66.94%, respectively. Except for the maxillary and mandibular canines in the tooth extraction group as well as the labial side of maxillary anterior teeth and the palatal side of maxillary central incisors of the non-extraction group, the alveolar bone heights of other sites significantly reduced (P<0.05). The reduction in the alveolar bone height of the tooth extraction group significantly exceeded that of the non-extraction group on the palatal side of maxillary incisors and the lingual side of mandibular anterior teeth (P<0.05). Alveolar bone height in the anterior tooth region decreases after orthodontic treatment for Angle's Class II division 1 malocclusion, being closely related to tooth position together with movement direction and amplitude.

Comparison of alveolar bone thickness and height after slow expansion using quad-helix or clear aligners

ObjectiveThe study was conducted to investigate the thickness and height of the alveolar bone of individual teeth after slow maxillary expansion (SME) with quad helix or clear aligner appliances and hypothesized that there is no difference in buccal alveolar bone thickness or heights in patients treated by either quad helix or clear aligners. Material and MethodsThis is a retrospective study; the records of 22 patients treated between December 2019 to April 2020 by dental arch expansion using either clear aligners or quad helix appliances were retrieved and studied. The results obtained through cone beam computed tomography (CBCTs) before and immediately after maxillary expansion (2 + 1 mm per side) were analyzed (11 in the Quad Helix group and 11 in the clear aligner). The data collected was analyzed using linear and angular measurements obtained through On-demand 3D App software. Furthermore, Statistical Package for Social Sciences (SPSS) version 25.0 was used to present the findings by mean and standard deviations, and Scheffe’s test was applied for comparing forces. ResultsThe results showed that the mean age of patients in the clear aligner group and Quad Helix was 16.27 ± 0.56 years and 15.5 ± 1.53 years, respectively. There was no difference in buccal alveolar bone thickness or heights in patients treated by either quad helix or clear aligners. This is due to the findings that suggest that there was a decrease in bone height and bone width when treated with a quad helix as compared to clear alignment. ConclusionIt can be concluded that the quad helix SME treatment affects alveolar bone integrity; therefore, clear aligners might be better for treating patients than the quad helix.

Characteristics of Spatial Changes in Molars and Alveolar Bone Resorption among Patients with Loss of Mandibular First Molars: A CBCT-Based Morphometric Study

To investigate the characteristics of spatial changes in molars and alveolar bone resorption among patients with loss of mandibular first molars. A total of 42 CBCT scans of patients with missing mandibular first molars (3 males, 33 females) and 42 CBCT scans of control subjects without loss of mandibular first molars (9 males, 27 females) were evaluated in this cross-sectional study. All images were standardized using the mandibular posterior tooth plane with Invivo software. The following indices regarding alveolar bone morphology were measured, including alveolar bone height, bone width, mesiodistal and buccolingual angulation of molars, overeruption of maxillary first molars, bone defects, and the capability of molar mesialization. The vertical alveolar bone height in the missing group was reduced by 1.42 ± 0.70 mm, 1.31 ± 0.68, and 1.46 ± 0.85 mm on the buccal, middle, and lingual side, respectively (no differences among the three sides; p > 0.05). Alveolar bone width was reduced the greatest at the buccal CEJ level and the least at the lingual apex level. Mandibular second molar mesial tipping (with mean of the mesiodistal angulation = 57.47 ± 10.34°) and lingual tipping (with mean of the buccolingual angulation = 71.75 ± 8.34°) were observed. The mesial and distal cusps of maxillary first molars were extruded by 1.37 mm and 0.85 mm, respectively. Buccal and lingual defects of alveolar bone occurred at the CEJ, mid-root, and apex levels. Through 3D simulation, the second molar cannot be successfully mesialized into the missing tooth position, and the difference between the available and required distances for mesialization was the greatest at the CEJ level. The duration of tooth loss was significantly correlated with the mesio-distal angulation (R = -0.726, p < 0.001), buccal-lingual angulation (R = -0.528, p < 0.001) and the extrusion of the maxillary first molar (R = -0.334, p < 0.05). Both vertical and horizontal resorption of alveolar bone occurred. Mandibular second molars exhibit mesial and lingual tipping. Lingual root torque and uprighting of the second molars are needed for the success of molar protraction. Bone augmentation is indicated for severely resorbed alveolar bone.

Guidance and rationale for the immediate implant placement in the maxillary molar.

While the reliability of immediate implant placement in the maxillary molar has been discussed, its significance is questionable. There have been no guidelines for case selection and surgical technique for successful treatment outcomes of immediate maxillary molar implants. Therefore, in this study, we classified alveolar bone height and socket morphology of the maxillary molar to establish guidelines for immediate implant placement. From 2011 to 2019, we retrospectively analyzed 106 patients with 148 immediate implants at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Inclusion and exclusion criteria were applied, and patient characteristics and treatment results were evaluated clinically and radiologically. A total of 29 tapered, sand-blasted, large-grit, and acid-etched (SLA) surfaces of implants were placed in 26 patients. The mean patient age was 64.88 years. Two implants failed and were reinstalled, resulting in a 93.10% survival rate. Fluctuating marginal bone level changes indicating bone regeneration and bone loss were observed in the first year following installation and remained stable after one year of prosthesis loading, with an average bone loss of 0.01±0.01 mm on the distal side and 0.03±0.03 mm on the mesial side. This clinical study demonstrated the significance of immediate implant placement in maxillary molars as a reliable treatment with a high survival rate using tapered SLA implants. With an accurate approach to immediate implantation, surgical intervention and treatment time can be reduced, resulting in patient satisfaction and comfort.

A quantitative three-dimensional comparative study of alveolar bone changes and apical root resorption between clear aligners and fixed orthodontic appliances

BackgroundThis study aimed to evaluate and compare the alveolar bone changes and to investigate the prevalence and severity of orthodontically induced inflammatory root resorption (OIIRR) of maxillary incisors in patients who received treatment with clear aligners (CA) versus conventional fixed appliances (FA), using cone-beam computed tomography (CBCT).MethodsOne hundred sixty maxillary incisors from 40 patients with similar baseline characteristics based on the American Board of Orthodontics discrepancy index scores were divided into the CA and FA groups. The dentoalveolar quantitative changes were analyzed using pre- (T0) and post-treatment (T1) CBCT. The measured parameters included alveolar bone thickness (ABT), alveolar bone height (ABH), root length (OIIRR), and maxillary incisor inclinations.ResultsPost-treatment, the average palatal and total ABT significantly decreased in central and lateral incisors in the FA group. In contrast, the CA group’s average labial ABT of the lateral incisors decreased considerably. Regarding the ABH, both groups showed significant labial and palatal marginal bone resorption. In both groups, root lengths significantly decreased after treatment (p < 0.005). The inter-group comparison revealed that ABT and root length had significantly decreased in the FA group compared to the CA group, while the ABH showed no significant difference between the two groups. The mean absolute reductions of ABT and OIIRR in the CA group were significantly less (− 0.01 ± 0.89 and 0.31 ± 0.42) than those in the FA group (0.20 ± 0.82 and 0.68 ± 0.97), respectively.ConclusionsCA and FA treatments appear to cause a significant ABT reduction and a statistically significant increased OIIRR in the maxillary incisor region, with a greater extent expected with FA treatment. However, the increased OIIRR values in the majority of both groups’ cases were not clinically significant. Both treatment modalities resulted in a significant ABH reduction, with the highest found in the labial side of lateral incisors in the CA group.

Evaluation of root resorption in the lower incisors after orthodontic treatment of skeletal Class III malocclusion by three-dimensional volumetric measurement with cone-beam computed tomography.

To investigate the volumetric changes of the lower incisor roots in skeletal Class III orthodontic patients with anterior crossbite after premolar extraction therapy. Thirty-six adults, aged 18-28 years, had four-premolar extraction treatment. Pre- and posttreatment cone-beam computed tomography (CBCT) images were used to assess the thickness and height of alveolar bone, root volume, and length. A paired t-test was used to detect changes in root volume and length before and after treatment. Pearson's correlation analysis was applied to estimate the correlation between root volume and dentoskeletal morphology. Both the central and lateral incisors had intrusion and tipping movement after treatment. Compared with pretreatment data, root length decreased significantly. The lingual root volume of root cervical, apical third, and the labial root volume of the root apical third decreased significantly (P < .05), among which the percentage of tooth loss at the tip volume was the highest. The pretreatment height of the alveolar ridge crest, thickness of the alveolar bone, and type of incisor movement were related to the volume and length loss. Volume and length loss in the apical third of the lower incisor roots in skeletal Class III patients treated with a Class III bicuspid extraction pattern is common. The pretreatment height of the alveolar ridge crest, thickness of the alveolar bone, and type of tooth movement are related to the loss.

Effect of piezocision-assisted lower second molar protraction on periodontal tissues, alveolar bone height, and lower second molar root resorption.

To assess the effect of piezocision on periodontal tissues and alveolar bone height and to detect lower second molar root resorption in piezocision-assisted mandibular second molar protraction compared to no-piezocision molar protraction. Twenty-one subjects (four males, 17 females, aged 22.43 ± 2.83 years) who presented with bilateral extraction of lower first molars were included. The patients were divided into two groups; Group 1: Piezocision-assisted molar protraction (right or left side of subjects) in which piezocision was performed immediately before lower second molar protraction and, Group 2: No-piezocision molar protraction in which lower second molar protraction was not surgically assisted. Plaque index (PI), gingival index (GI), periodontal pocket depth (PPD), width of keratinized gingiva (WKG), gingival recession (GR), lower second molar mesial root resorption, alveolar bone height, and mandibular bone height were recorded at T1 (immediately before molar protraction) and at T2 (after second molar space closure). In the piezocision-assisted molar protraction group, significant changes were detected in the WKG (P < .001), GR (P < .05), and the mandibular bone height (P < .001). Compared to the no-piezocision group, piezocision-assisted molar protraction resulted in an increased WKG (P < .001) and less second molar mesial root resorption (P < .01). Piezocision does not have any detrimental effect on the periodontium and produces less root resorption.

Analysis of morphometric changes in the anterior alveolar bone in bimaxillary protrusion adult patients after retraction with cone-beam CT

Objective: To measure and analyze the morphometric changes in the anterior alveolar bone during treatment and retention stage after retraction in bimaxillary adults using cone-beam CT(CBCT). Methods: Fifteen adult patients, four males and 11 females, aged 19 to 28 years[(22.2±3.1) years], who have completed orthodontic treatment and extracted four first premolar teeth for retraction in the Department of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University from January 2016 to December 2018 were selected. CBCT was taken to assess the labial and palatal vertical bone level, total bone thickness at crest area, middle root area and apical area in pre-treatment (T1), post-treatment (T2) and at follow-up (maintained for more than two years) (T3). The differences in alveolar bone morphology at different stages were compared by single factor repeated measure ANOVA, and Pearson correlation analysis was performed on the amount of alveolar bone change in treatment stage and retention stage. Results: There were statistically significant differences in the alveolar bone height of the palatal side of maxillary anterior teeth, the labial side of maxillary lateral incisors and canine among three time points (P<0.05). The height difference of palatal alveolar bone of anterior teeth in T1-T2 stage was statistically significant (P<0.05). Palatal alveolar bone of upper and lower central incisors decreased by (1.52±0.32) and (4.96±0.46) mm, respectively. The height difference of anterior palatal alveolar bone was statistically significant in T2-T3 stage(P<0.05), the palatal alveolar bone height of central incisors increased by (1.20±0.27) and (3.14±0.35) mm respectively. The height difference of palatal alveolar bone in the anterior teeth of T1-T3 stage was statistically significant (P<0.05), and the height of palatal alveolar bone of central incisors was decreased (0.33±0.11) and (1.82±0.39) mm, respectively. There were statistically significant differences in the thickness of the cervical and middle root alveolar bone of anterior teeth among three time points (P<0.05). The difference of alveolar bone thickness of the cervical and middle root of anterior teeth at T1-T2 was statistically significant (P<0.05). decreased by (0.63±0.10) and (0.67±0.09) mm in lateral incisors, respectively. In the T2-T3 stage, the alveolar bone thickness of the crest area of the lower anterior teeth was significantly different (P<0.05), the alveolar bone thickness of mandibular central incisor crest area increased (0.09±0.03) mm. There were statistically significant differences in alveolar bone thickness in crest area and middle root of the incisors during T1-T3 stage (P<0.05), among which the middle root decreased by (0.38±0.16) mm and (0.63±0.13) mm, respectively. There was no statistically significant difference in other areas (P>0.05). The change of alveolar bone height in palatal side of upper anterior teeth at T2-T3 was very strongly negatively correlated with the change in T1-T2. The change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor root and neck were moderately strongly negatively correlated (r≤-0.8, P<0.001), the change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor crest area were moderately strongly negatively correlated (-0.8<r≤-0.4, P<0.05). Conclusions: For adult patients after retraction, anterior alveolar bone decreased significantly. In the retention stage, the same degree of bone apposition will occur, but still have alveolar bone loss compared with pre-treatment. The amount of alveolar bone change in the retention stage correlated with the amount of alveolar bone change in the treatment stage.

Influence of inflammation on bleeding and wound healing following surgical extraction of impacted lower third molars

ObjectiveThis study aimed to investigate the effect of inflammatory states following impacted lower third molar (ILTM) surgery regarding postoperative bleeding and wound healing.MethodsThe study included patients who underwent extraction of ILTMs associated with or without inflammatory conditions. Post-extraction bleeding and wound healing were assessed. In addition, mean grey values (MGVs) of alveolar bone and bone height using an orthopantomography radiograph were analyzed.ResultsA total of 376 patients were enrolled; 171 pericoronitis, 51 pulpitis, 44 chronic periapical periodontitis, 36 chronic periodontitis, and 74 control. The bleeding score in the control group was significantly lower than in the periapical periodontitis and periodontitis groups. Excellent wound healing for control, pericoronitis, pulpitis, periapical periodontitis, and periodontitis groups was (78.38%, 35.67%, 70.59%, 70.45%, and 33.33%, respectively). Patients with pericoronitis and periodontitis had significantly poorer wound healing (P < 0.01). The MGV in periapical periodontitis and periodontitis was considerably lower than in the control group.ConclusionsThe inflammatory conditions associated with ILTMs increase the risk of bleeding. So suturing with the placement of local hemostatic agents over a pressure pack alone is recommended. The poorest wound healing was in localized gingival inflammation. Furthermore, MGV was affected by age and was lower with periapical periodontitis.

Clinical efficacy of extra-short implant (4 mm) placed in posterior areas: a Meta-analysis.

This study aimed to systematically evaluate the safety and clinical efficacy of 4 mm-extra-short implant (ESI) placement in severely atrophic posterior areas. Databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang from January 1, 2010, until August 31, 2022, were searched to identify randomized controlled trials or controlled clinical trials related to ESI and standard implants (SI). An additional hand search of the references of included articles was also conducted. Meta-analyses were carried out with RevMan 5.4 software. A total of 11 studies were included, involving six randomized controlled trials and five controlled clinical trials. The meta-analyses indicated that when implants were placed in the posterior area, the implant survival rate between ESI and SI did not significantly differ [RR=1.23, 95%CI (0.66, 2.27), P=0.52]. ESI resulted in significantly stable marginal bone level [MD=-0.16, 95%CI (-0.25,-0.07), P=0.000 7] and less biological complications [RR=0.34, 95%CI (0.19, 0.62), P=0.000 4] but more mechanical complications [RR=2.89, 95%CI (1.05, 7.92), P=0.04]. Based on the limited evidence, ESI could achieve clinical outcomes similar to those of SI when the height of the posterior alveolar bone is less than 5 mm, with lower technical sensitivity and fewer postoperative clinical complications than SI. Due to insufficient evidence and limited sample size, further clinical trials are needed to verify the long-term efficacy of ESI.

Basic fibroblast growth factor/chitosan derivatives/collagen composite thermosensitive hydrogel promotes perio-dontal tissue regeneration in rats.

To investigate the feasibility of different thermosensitive composite hydrogels from chitosan derivatives as scaffold materials for periodontal tissue engineering. Three chitosan derivatives with different biological characteristics were prepared, namely, sulfonated chitosan (SCS), phosphorylated chitosan (PCS), and phosphorylated sulfonated chitosan (PSCS). Three thermosensitive composite hydrogels were constructed using basic fibroblast growth factor (bFGF), the chitosan derivatives, and collagen. Twenty male Wistar rats were randomly divided into control group, blank group, bFGF/SCS/collagen composite thermosensitive hydrogel group, bFGF/PCS/collagen compo-site thermosensitive hydrogel group, and bFGF/PSCS/collagen composite thermosensitive hydrogel group. Then, three-wall intrabony defects were established. The defects were treated with the different kinds of thermosensitive composite hydrogels. After 6 weeks of surgery, the animals were killed, and specimens were collected. Then, gross observation, hematoxylin-eosin staining, and Masson staining were performed. The bFGF/chitosan derivatives/collagen composite thermosensitive hydrogel groups and the control group had statistical differences in the relative alveolar bone height, relative epithelial down growth and grading count score of periodontal tissue regeneration (P<0.05). bFGF/chitosan derivatives/collagen composite thermosensitive hydrogels have good application prospects in periodontal tissue engineering.

A Three-dimensional Analysis of Nasopharyngeal Airway Characteristics in Subjects with Cleidocranial Dysplasia: A CBCT Study.

Children with congenital or acquired craniofacial abnormalities exhibit an array of dental abnormalities like supernumerary teeth, failure of permanent teeth eruption, decreased alveolar bone height, etc. These subjects undergo complex corrective surgeries to improve esthetics and functional derangements, predisposing them to risks of obstructive sleep apnea due to airway obstruction. The various corrective or therapeutic procedures done might lead to airway complications in these children. The study designed was for retrospective evaluation and comparison of the nasopharyngeal (NP) characteristics and assessment of the airway volume three-dimensionally in normal vs cleidocranial subjects. Cone-beam computed tomography (CBCT) scans of nine subjects with cleidocranial dysplasia (CCD) were compared with the control sample, and matched for age and sex. A 3D-DOCTOR software by Able Software Corporation was used to calculate the volumetric measurements. The correlation and differences among the values were assessed using an independent t-test and Pearson analysis. The values of lower airway width, upper adenoid width, McNamara upper pharynx, retroglossal area, and total pharyngeal area were found to be reduced in the cleidocranial subjects. The NP airway volume and total airway volume also significantly decreased. Cleidocranial dysplasia (CCD) being a rare genetic disorder, we could find only nine established cases. Hence our study can be called a pilot study but may work to establish a database of any sort of skeletal and dental anomaly with possible specific respiratory characteristics affecting airway. Chaturvedi S, Chaturvedi Y, Chowdhary S, et al. A Three-dimensional Analysis of Nasopharyngeal Airway Characteristics in Subjects with Cleidocranial Dysplasia: A CBCT Study. Int J Clin Pediatr Dent 2022;15(5):520-524.

Comparison of bioresorbable bone substitutes, carbonate apatite and β‐tricalcium phosphate, for alveolar bone augmentation with simultaneous implant placement

AbstractAimThis study histologically compared two bioresorbable bone substitutes with different composition, carbonate apatite (CO3Ap) and beta‐tricalcium phosphate (β‐TCP), through alveolar bone augmentation with simultaneous titanium implant placement in beagle dogs.MethodsBone defects (length 7 mm, width 2 mm, and depth 6 mm) were created bilaterally at mandibular premolar sites and augmented with either CO3Ap or β‐TCP granules after titanium implant installation. The specimens with the surrounding tissue were harvested from the mandible at 4, 12, and 24 weeks postoperatively, and histological evaluation was performed.ResultsMost β‐TCP granules dissolved in early stages postoperatively, resulting in a lower volume of alveolar bone surrounding the titanium implant. By contrast, in the case of CO3Ap group, the alveolar ridge was reconstructed without reducing the alveolar bone height, and almost all implant threads were covered with new bone by at least 12 weeks postoperatively. Quantitatively, the CO3Ap group showed a significantly higher percentage of new bone formation in the alveolar ridge portion at all follow‐ups. Additionally, it demonstrated a significantly higher bone‐to‐implant contact ratio than that of the β‐TCP group at 12 and 24 weeks after implantation (70.8 ± 5.6% vs. 29.3 ± 16.4% and 54.8 ± 6.9% vs. 41.8 ± 2.2%, respectively).ConclusionIn conclusion, based on the superior outcomes noted in this study, CO3Ap is useful for clinical use in alveolar bone augmentation with simultaneous implant placement.

Influence of alveolar bone height on the biomechanical behavior of roots restored with custom-made posts-and-cores.

This study evaluated the influence of alveolar bone height and post type on compressive force resistance, fracture pattern, and stress distribution in endodontically treated teeth. Bovine roots were endodontically treated and divided into eight groups (n=10) according to alveolar bone height (normal alveolar bone and alveolar bone loss - 2 and 5 mm from the margin of the crown, respectively) and post type (prefabricated glass fiber post, anatomic glass fiber post, customized milled glass fiber post-and-core and customized milled polyetheretherketone (PEEK) post-and-core). Mechanical fatigue was simulated (300.000 cycles/50 N/1.2Hz). Compression force resistance (N) was analyzed by two-way ANOVA and Tukey test (α=0.05). Fracture patterns were described as percentages. Stress distribution was analyzed by finite element analysis. Significant diferences were found for alveolar bone height (P < 0.0001): normal alveolar bone groups showed higher mean values of compression force resistance compared to alveolar bone loss groups, while no significant differences were found for post type (P=0.4551), and there was no double interaction between them (P=0.5837). Reparable fractures were more predominant in normal alveolar bone groups, especially in the milled glass fiber and PEEK post-and-core groups. Stress distribution was similar in groups with prefabricated glass fiber posts and milled PEEK posts-and-cores, and the alveolar bone loss condition significantly increased stress concentration and strain values, mainly on apical dentin. Alveolar bone loss due to physiological aging and/or periodontal disease may lead to increased risk of restored tooth failure, although milled glass fiber and PEEK posts-and-cores provide more reparable fractures. Custom-made glass fiber and PEEK post-and-cores are interesting options, since they enable clinicians to work with a single-body post-and-core system that avoid several materials interfaces and fits well in the root canal provided promising results to improve the failure behavior of restored roots, as they offer more reparable fractures even in situations of alveolar bone loss.

Three-year observations on the effect of different cusp inclinations on the restoration of short maxillary first molar implants: A randomized controlled trial.

Objective: To investigate the effect of different cusp inclination on short implant prosthesis of maxillary first molar after 3years of weight-bearing in biology and mechanics. Methods: The clinical patients were randomly selected from the database and divided into four groups A, B, C, and D according to the cusp inclination of the maxillary first molar short implant restoration (4.8mm × 8mm, Dentium). 20 cases in each group. The cusp inclination was 10 degrees-15 degrees, 15 degrees-20 degrees, 20 degrees-25 degrees, 25 degrees-30 degrees. After 3years of weight-bearing, cone beam computed tomography (CBCT) and Florida probe were used to measure and observe the height of alveolar bone (H), periodontal probing depth (PD) and modified sulcus bleeding index (MBI). Visual analogue scale (VAS) was used to evaluate the overall satisfaction of patients, and the mechanical complications of each group within 3 years of implant weight-bearing were counted. Results: The H and PD of group D were 1.09 ± 0.23 and 2.19 ± 0.11 respectively, which were significantly higher than those of group A, B and C (p < 0.05). There was no significant difference in MBI between groups A-D (p > 0.05). The VAS scores of group B and group C were 88.36 ± 5.12 and 88.70 ± 4.52 respectively, which were higher than those of group A and group D (p < 0.05). The incidence of food impaction, porcelain collapse and abutment loosening in group D were 40.0%, 25.0% and 15.0% respectively, which were higher than those in group B and C (p < 0.05). Conclusion: The risk of biological and mechanical complications increases after long-term weight-bearing of maxillary first molar short implant prostheses with high cusp inclination. The cusp inclination of short implant prostheses should be designed as low as 25 degrees.

Incisors' bone height and inclination changes after orthodontic treatment with a self-ligating passive system.

This study aimed to evaluate changes in the alveolar buccal bone height of maxillary and mandibular incisors after orthodontic treatment with a self-ligating passive system and to assess the correlation between bone height and incisor inclination. Pre (T1) and post-treatment (T2) cone-beam computed tomography images of patients treated with the Damon 3MX appliance system were measured to quantify the alveolar buccal bone height of the maxillary incisors. The incisor's inclination was measured in digital models. Paired t-test was used to evaluate the changes between T1 and T2, and Pearson's coefficient was used to test the correlation. All teeth presented statistically significant alveolar buccal bone loss at T2. A statistically significant buccal inclination was observed only for the lower left lateral incisors. There was no correlation between bone height changes and incisor inclination. Orthodontic treatment with a self-ligating passive system showed changes in alveolar height, but these changes were not correlated with incisor inclination. Key words:Passive self-ligating brackets, orthodontics, corrective, treatment outcome, alveolar bone loss.