Buccal Bone Thickness Research Articles

Clinical and radiographic evaluation of jumping distance management using a collagen matrix in flapless immediate implant placement.

Improvement in implant design has made implant dentistry a challenging treatment modality worldwide. This study aimed to investigate the efficacy of a xenogeneic collagen matrix in managing 3-4-millimeter gaps in flapless immediate implant placement. Twenty-two patients received 39 immediate implants via the flapless approach. Patients with intact bony walls, buccal bone thickness ≥2 mm and a jumping distance of 3-4 mm were included in this study. The gap between the implant and the socket walls was filled with a xenogeneic collagen matrix (Collacone®). The final clinical and radiographic evaluations were performed at least 24 months following functional loading. There was no early or late failure, and the implants showed a 100% survival rate. The mean mesial (0.28 ±0.39 mm) and distal (0.28 ±0.39 mm) marginal bone loss (MBL) at the site of incisors was not significantly different from the values at the site of premolars and molars (0.30 ±0.42 mm and 0.34 ±0.48 mm, respectively). The evaluation of the implant success index (ISI) score revealed no difference between the mandible and the maxilla (p = 0.700), or incisors compared with premolars and molars (p = 0.420). The only significant difference was in terms of distal MBL, which was higher in the maxilla (0.39 ±0.49 mm) than in the mandible (0.12 ±0.23 mm) (p = 0.040). Within the limitations of this study, it seems that the application of a xenogeneic collagen matrix to manage 3-4-millimeter gaps in carefully selected cases may bring promising outcomes.

Efficacy of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) in late adolescents and adults: a systematic review and meta-analysis.

SummaryBackgroundMiniscrew-Assisted Rapid Palatal Expansion (MARPE) is a non-surgical treatment for transverse maxillary deficiency. However, there is limited evidence concerning its efficacy.ObjectivesThis systematic review aims to evaluate the efficacy of MARPE in late adolescents and adults by assessing success rate and skeletal and dental transverse maxillary expansion, as well as treatment duration, dental and periodontal side effects and soft tissue effects.Search methodsSeven electronic databases were searched (MEDLINE, Embase, Cochrane Library, Web of Science, Scopus, ProQuest and ClinicalTrials.gov) without limitations in November 2020.Selection criteriaRandomized and non-randomized clinical trials and observational studies on patients from the age of 16 onwards with transverse maxillary deficiency who were treated with MARPE and which included any of the predefined outcomes.Data collection and analysisInclusion eligibility screening, data extraction and risk of bias assessment were performed independently in duplicate. When possible, exploratory meta-analyses of mean differences (MDs) with their 95% confidence intervals (CIs) were conducted, followed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis of the evidence quality.ResultsEight articles were included: two prospective and six retrospective observational studies. One study had a moderate risk of bias, whereas seven studies had a serious risk of bias. GRADE quality of evidence was very low. MARPE showed a high success rate (mean: 92.5%; 95%CI: 88.7%–96.3%), resulting in a significant skeletal width increase (MD: 2.33 mm; 95%CI: 1.63 mm–3.03 mm) and dental intermolar width increase (MD: 6.55 mm; 95%CI: 5.50 mm–7.59 mm). A significant increase in dental tipping, a decrease in mean buccal bone thickness and buccal alveolar height, as well as nasal soft tissue change was present (P < 0.05). The mean duration of expansion ranged from 20 to 126 days.LimitationsOne of the main drawbacks was the lack of high-quality prospective studies in the literature.Conclusions and implicationsMARPE is a treatment modality that is associated with a high success rate in skeletal and dental maxillary expansion. MARPE can induce dental and periodontal side effects and affect peri-oral soft tissues. Given the serious risk of bias of the included studies, careful data interpretation is necessary and future research of higher quality is strongly recommended.RegistrationPROSPERO (CRD42020176618).FundingNo grants or any other support funding were received.

Comparison of skeletal and dentoalveolar changes between pure bone-borne and hybrid tooth-borne and bone-borne maxillary rapid palatal expanders using cone-beam computed tomography

Objectives: The objectives of the study were to compare the skeletal, dentoalveolar, and periodontal changes between two types of microimplant-assisted rapid maxillary expansion appliances: The bone-anchored maxillary expanders (BAME) and the tooth-bone-anchored maxillary skeletal expander (MSE). Materials and Methods: Thirty-four patients with a transverse maxillary deficiency were divided into two groups; the first group (16 patients, average age 14.9 years) was treated with the MSE appliance, and the second group (18 patients, average age 13.8 years) was treated with the BAME appliance. Cone-beam computed tomography scans were taken at pre-treatment (T1) and immediately post-expansion (T2) to measure the changes in midpalatal suture opening, total expansion (TE), alveolar bone bending, dental tipping (DT), and buccal bone thickness. Data were analyzed using paired t-test and two-sample t-test. Results: Midpalatal suture separation was found in 100% of the patients in both groups. The TE at the first molar was 5.9 mm in the MSE group and 4.7 mm in the BAME group. The skeletal contributions were 56% and 83% of TE for the MSE and BAME groups, respectively. Significantly less dental buccal tipping and buccal bone loss were found with the BAME group. The midpalatal suture in both groups exhibited a parallel opening pattern in the axial plane. Conclusion: The use of BAME appliance resulted in greater skeletal effects, less dental tipping, and less buccal bone reduction compared to MSE appliance (immediately after maxillary expansion).

Immediate single-tooth implant placement with simultaneous bone augmentation versus delayed implant placement after alveolar ridge preservation in bony defect sites in the esthetic region: A 5-year randomized controlled trial.

It is unclear if an intact buccal bony plate is a prerequisite for immediate implant placement in post-extraction sockets. The aim of this 5-year randomized controlled trial was therefore comparison of peri-implant soft and hard tissue parameters, esthetic ratings, and patient-reported satisfaction of immediate implant placement in post-extraction sockets with buccal bony defects of ≥ 5mm in the esthetic zone, with delayed implant placement after ridge preservation. Patients presenting a failing tooth in the esthetic region and a buccal bony defect of ≥ 5mm after extraction were randomly assigned to immediate (Immediate group, n=20) or delayed (Delayed group, n=20) implant placement. Second-stage surgery and placement of a provisional restoration occurred 3 months after implant placement in both groups, followed by definitive restorations 3 months thereafter. The follow-up was 5 years. Marginal bone level (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded. Mean marginal bone level change was -0.71 ± 0.35mm and -0.54 ± 0.41mm in respectively the Immediate group and the Delayed group after 5 years (P=0.202). This difference, and in other variables, was not significant. Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in post-extraction sockets with buccal bony defects of ≥ 5mm, were comparable to those following delayed implant placement after ridge preservation in the esthetic zone.

Immediate Implant Placement with Buccal Bone Augmentation in the Anterior Maxilla with Thin Buccal Plate: A One-Year Follow-Up Case Series.

To evaluate the buccal bone thickness of immediate implant placement with buccal bone augmentation in patients with a thin buccal plate in the esthetic zone. Eighteen consecutive patients requiring a single tooth replacement in the anterior maxillary zone with a thin plate (<1 mm) were included and received immediate implant placement with narrow-diameter implants. Patients received buccal bone augmentation (both internal and external socket bone grafting) with deproteinized bovine bone mineral (DBBM) and an absorbable membrane. The final restoration was delivered after 8 months. Cone-beam CT scans were performed before surgery (CBCT0), immediately after surgery (CBCT1), at final restoration delivery (CBCT2), and at 1-year follow-up after the final restoration (CBCT3) to evaluate the buccal bone thickness and ridge width. A repeated measures ANOVA and Bonferroni correction for multiple comparisons were applied for statistical analysis of changes within different time points (α = 0.05). Fifteen of the 18 enrolled patients were available for analysis at the 1-year follow-up after final restoration. The mean buccal bone thickness at 2 mm apical to the implant-abutment junction (IAJ-2) were 3.59 mm (range: 3.04-4.58 mm), 2.79 mm (range: 2.25-3.78 mm), and 2.52 mm (range: 1.72-3.36 mm), respectively, at CBCT1, CBCT2, and CBCT3. A statistical significance was observed for buccal bone thickness change between CBCT1 and CBCT2 at IAJ-2 (F = 17.948, p = 0.001). The net gains of the ridge width from CBCT0 to CBCT1, CBCT1 to CBCT2, and CBCT2 to CBCT3 were 1.08 mm, -0.94 mm and -0.04 mm at 4 mm apical to the cementum-enamel junction, respectively. No statistical significance was observed for the change in ridge width from CBCT0 to CBCT3 (F = 10.518, p = 1.000). Simultaneous buccal bone augmentation may maintain a predictable buccal bone thickness for immediate implant placement in the maxillary anterior sites with a thin buccal plate (<1 mm) at 1-year follow-up after final restoration.

Evaluation of Alt-RAMEC With Facemask in Patients With Unilateral Cleft lip and Palate (UCLP) Using Cone Beam Computed Tomography (CBCT) and Finite Element Modeling-A Clinical Prospective Study.

Evaluate the effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol on patients with unilateral cleft lip and palate (UCLP) along with maxillary protraction using cone beam computed tomography (CBCT) records and a finite element modeling (FEM) model. Twenty-five patients (aged 9-13 years) with UCLP having a GOSLON score 3 were selected for this prospective single-arm cohort study after obtaining necessary informed consent. A 9-week Alt-RAMEC protocol using a custom-made fan-shaped expansion screw was initiated, which was followed by 6-month facemask wear. Pre (T1) and posttreatment (T2) records including CBCT were taken and were evaluated for treatment changes in all 3 dimensions using paired t test. Additionally, a FEM model (ANSYS 15.0) using the Alt-RAMEC protocol was also analyzed for the displacement and stress on various craniofacial structures. Significant forward movement of the maxilla along with clockwise rotation of mandible along with statistically significant increase in lower molar height and upper incisor proclination (P < .05) was observed. CBCT evaluation showed a statistical significant decrease in buccal alveolar bone thickness and increase in molar inclination (P < .05). Finite element modeling analysis highlighted that the maximum displacement occurred at the anterior region with stresses radiating till the anterior nasal spine, zygomatic arch, and sphenoid bone. Alt- RAMEC protocol combined with facemask protraction can lead to significant maxillary advancement, with some transient decrease in buccal bone thickness noted thereby warranting long-term studies to further assess its effect on the dentofacial apparatus.

Height difference between the vestibular and palatal walls and palatal width: a cone beam computed tomography approach

BackgroundThe objective of this study was to measure two parameters involved in tri-dimensional implant planning: the position of the buccal and palatal bone wall and the palatal thickness.MethodsCone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The height difference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall.ResultsThe mean values in the maxilla were 1.7 ± 0.9 mm for central and lateral incisors, 2.2 ± 1.7 mm for canines, 1.6 ± 0.9 mm for premolars and 1.9 ± 1.5 mm for molars. In the lower jaw, the mean values were 1.3 ± 0.8 mm for incisors, 1.7 ± 1.2 mm for canines, 2.3 ± 1.3 mm for premolars, and 2.6 ± 1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height differences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall.ConclusionsThe buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and mandible, except in the upper canines and premolars and the lower molars.

Anatomical and Morphological Assessment of Nasopalatine Canal in Pediatric and Adolescent Population via Cone Beam Computed Tomography.

Anatomical and morphological structure of nasopalatine canal (NPC) is important for surgical techniques carried out on the maxilla. The aim of the present study was to analyze the anatomical and morphological characteristics of the NPC among pediatric and adolescent population using cone beam computed tomography (CBCT). A total of 437 cases were analyzed using CBCT images in this retrospective, cross-sectional study. Shape was analyzed as hourglass, cone, funnel, banana, cylindrical, and tree branch like. Number of foramina Stenson (FS) was evaluated through coronal, axial, and sagittal views. Landmark evaluation involved; diameter of FS, diameter of incisive foramen, diameter at the mid-canal length, NPC length, and narrowest buccal bone thickness. Pathology presence near NPC was evaluated to determine alterations on the landmark metrics. Nasopalatine canal shape distribution revealed 32% hourglass, 9.6% conic, 10.8% funnel, 11.9% banana, 29.5% cylindrical and 6.2% tree branch. Number of FS (P = 0.021; P < 0.05), diameter of FS (P = 0.041; p < 0.05), NPC length (P: 0.020; P < 0.05), and narrowest buccal bone thickness from the mid-canal length was significantly higher in males (P: 0.000; P < 0.05). Diameter of incisive foramen and diameter at the mid-canal length revealed no significance among genders (P1 = 0.318, P2 = 0.105; P > 0.05). Incidence of pathology near NPC is 20.8% and was not affected by gender (P = 0,192; P > 0.05). The current study demonstrates significant variations of NPC morphology among patients. Therefore, CBCT analysis is highly recommended for clinicians to reduce the complications in oral and maxillofacial surgery practices and to provide better surgical outcomes.

The use of CBCT to asses buccal bone thickness overlying mandibular anterior teeth

Objectives: the aim of this study was to determine the relationship between gingival width with respect to the underlying bone thickness in mandibular anterior sextant.Material and metods: 40 CBCT were included. Buccal bone thickness was measured at 3, 4.5, 6, 8 mm apical to the cement–enamel junction (CEJ). In addition, the apicoincisal gingival width was measured.Results: at 3 mm from the cement-enamel junction, the buccal bone plate was in 69.4% of cases, the average thickness of buccal bone plate for all teeth was less than 1.0 mm, at the level of 4.5 and 6 mm in 30,6% of cases “Absence” of the external cortical plate, the thickness of which gradually increased in the apical direction (8 mm). When the efficiency is less than 2 mm, the effect of the absence of the external cortical plate according to CBCT data was more often observed.Conclusion: in this study revealed the relationship between the gingival width and the anatomical features of the buccal bone plate.

Factors Affecting Implant Stability Quotients at Immediately and Conventionally Loaded Implants in the Posterior Maxilla: A Split-Mouth Randomized Controlled Trial.

To assess primary and secondary stability of variable-thread tapered implants in the posterior maxilla and analyze the impact of various factors on implant stability quotients (ISQs). Twenty-six subjects received 3-4 adjacent implants in the maxillary premolar-molar sextants to replace bilateral tooth loss. The implants on one side were immediately loaded with a provisional fixed prosthesis regardless of their primary stability. The contralateral control implants were conventionally loaded. Bone quality was subjectively recorded and primary stability was assessed by means of insertion torque values (ITVs) and ISQs in 4 directions. Secondary stability was measured by ISQ at definitive prosthesis delivery (3-3.5 months postoperatively), and 12 months after definitive loading. The impact of measurement direction, loading protocol, time, site-related (bone quality, implant position, crestal buccal bone thickness, apical cortical anchorage), and implant-related (implant dimensions, abutment height) variables on ISQs was assessed. For logistic reasons, ISQs were obtained for only 18 patients with 60 test and 60 control implants. Most of the implants (82%) at baseline had their lowest ISQ on the buccal aspect. There were no significant differences between ISQs measured in the buccal and palatal directions, or between ISQs in the mesial and distal directions. The mean of buccal and palatal ISQs was significantly lower than the mean of the 2 interproximal measurements at all evaluation periods. ISQs were not significantly different between the 2 loading groups at any time point. All implants showed a time-dependent increase in ISQs. Baseline ISQ correlated weakly with bone quality and ITV. None of the variables had a significant impact on baseline ISQs, except for implants in second molar sites which showed poorer primary stability than first premolars. Measurement direction and time are the most significant parameters affecting ISQs of variable-thread tapered implants in the posterior maxilla.

Cone-beam computed tomography assessment of the buccal bone thickness in anterior maxillary and mandibular teeth

Introduction. The aim of this study was to assess the buccal bone thickness in anterior maxillary and mandibular teeth and to provide information important during immediate implant placement. Material and Methods. The study included 245 cone-beam computed tomography scans. The buccal bone thickness was measured in the sagittal plane of the maxillary and mandibular anterior teeth at five points (M1 - M5) (2 mm apart), starting 2 mm from the cementoenamel junction in the coronal to apical position along the roots. Results. The lowest mean buccal bone thickness was observed at M1 point in all teeth in both jaws while the highest mean buccal bone thickness was observed at M4 (maxilla) and M5 (mandible). An increase of the buccal bone thickness was established at every subsequent measurement point perpendicular to the long axis of the tooth (p &lt; 0.001). The buccal bone thickness was less than 1 mm in more than 60% of all teeth in the maxilla and mandible at all measurement points. A statistically significant difference in the thickness of the buccal bone in relation to the patients? age was found at all measurement points, except at M4 point of the anterior teeth of the maxilla (p = 0.456) and mandible (p = 0.109). Conclusion. The buccal bone thickness in anterior maxillary and mandibular teeth is less than 1 mm in more than 60% at all measurement points. The buccal bone thickness tends to increase from a coronal to apical position along the roots.

Anatomical Analysis of Mandibular Posterior Teeth using CBCT: An Endo-Surgical Perspective.

Objective:This study sought to analyse the relationship between mandibular posterior teeth and the surrounding anatomical structures.Methods:A total of 170 CBCT images were examined to obtain measurements regarding the following: buccolingual (BL) and mesiodistal (MD) root thickness at the standard level of resection (3 mm from the apex), the thickness of the overlying buccal and lingual bone at the same level, the proximity of the mandibular canal (MC) to the apices of the mandibular posterior teeth, as well as the horizontal location of the mental foramen (MF).Results:The BL root width at 3 mm from the apex was the broadest at the mesial roots of the first molars with males: 5.33±0.99 mm and females: 5.16±0.88 mm (mean±SD). The root width was narrowest at the second premolars (males: 3.80±0.83 mm; females: 3.61±0.60 mm). At the same level; the buccal bone was thickest over the distal roots of the second molars (males: 6.92±1.85 mm; females: 6.95±1.95 mm) and thinnest over the first premolars (males: 1.73±0.93 mm; females: 1.49±1.01 mm), while the lingual bone was thickest over the distal roots of the first molars (males: 5.58±1.36 mm; females: 4.52±1.24 mm) and thinnest over the distal roots of the second molars (males: 3.13±1.50 mm; females: 2.60±1.46 mm). The nearest root apices to the MC were the distal roots of the second molars (male: 1.21±1.45 mm; female: 1.75±1.97 mm), while the furthest were the mesial roots of the first molars (male: 4.00±2.39 mm; female: 4.77±2.58 mm). The most common horizontal location of the MF was between the first and second premolars (51.8%). The lingual bone was significantly thinner over both roots of first molars in females (P<0.05).Conclusion:As the position of the teeth became more posterior, the buccal bone thickness increased, the lingual bone thickness decreased, and the distance to the MC became closer. CBCT analysis provides distortion- and superimposition-free images of the relevant anatomic structures.

Study of mandibular thickness in dentulous and edentulous mandibles

There are several methods of reconstruction for lower human jaw, but the most common and safest is using plates and screws. The size of the lower jaw bone varies from person to person, therefore plates and screws are available in different sizes.1 A critical buccal bone thickness of 2 mm is recommended to prevent vertical resorption. A minimum bone thickness of 6 mm would be required for successful placement of a standard-sized ±4-mm-diameter implant.2 In the present study Mandibular Body Thickness (MBT) was studied in 110 dry mandibles to evaluate the ideal length of dental implants used during the corrective procedures on the mandibular alveolar process. All the mandibles in our study had adequate bone thickness needed for implant placement without traumatizing the sublingual artery. Keywords: Mandible, Symphysis menti, Premolar, Molar, Reconstruction, Maxillofacial surgery.

Maxillary dental and skeletal effects after treatment with self-ligating appliance and miniscrew-assisted rapid maxillary expansion

The objective of the present study was to compare the maxillary dental and skeletal effects after treatment with self-ligating appliance and miniscrew-assisted rapid maxillary expansion (MARPE). The sample comprised 37 patients with Class I malocclusion treated without tooth extraction, divided into 2 groups: group 1 comprises 21 patients with a mean age of 19.55years (standard deviation=1.31), submitted to orthodontic treatment with Damon self-ligating appliance, and evaluated until the end of the alignment and leveling stage. Group 2 comprises 16 patients with a mean age of 24.92years (standard deviation=7.60), with maxillary atresia, who underwent MARPE, and were evaluated after the removal of the expander. Buccal bone thickness; dental inclinations; and transverse distances of the maxillary arch, nasal base, and jugula widths were measured on cone-beam computed tomography scans before and after treatment. The intergroup comparison was performed with the independent t test. With treatment, there was a significantly greater decrease in buccal bone thickness of canines and premolars in the self-ligating group, the premolars presented a greater buccal inclination in the self-ligating group, and the intercanine and intermolar distances and nasal base and jugula widths showed significantly greater increases in the MARPE group than in the self-ligating group. MARPE treated more severe skeletal transverse maxillary discrepancies and obtained better results than self-ligating appliances in terms of buccal bone loss, tooth inclination, and transverse skeletal increase of the maxilla. MARPE presented more skeletal effects and self-ligating appliances, more dental effects.

Buccal Bone Changes Around First Permanent Molars and Second Primary Molars after Maxillary Expansion with a Low Compliance Ni-Ti Leaf Spring Expander.

Background: Vestibular bone thickness changes and dento-alveolar buccal tipping of second primary molars and of first molars after maxillary expansion performed with a slow maxillary expansion protocol was investigated. Methods: Twenty patients (mean age 7.3 ± 0.9 years old; 9 male and 11 female) were treated according to the Leaf Expander protocol. Buccal alveolar bone thickness (BT), buccal alveolar bone height (BH), inter-dental angle (TIP), and inter-molar width (IW) regarding first molars and second primary molars were calculated before and after expansion on cone beam computed tomography (CBCT) images. Descriptive statistics and paired t-tests were used to assess changes between the pre-treatment and post-treatment measurements. Results: Bone thickness vestibular to second primary molars and intermolar width of both teeth were the only variables that showed statistically significant changes. Conclusions: It appears that buccal bone thickness vestibular to first molars was not significantly reduced after maxillary expansion with the Leaf Expander. The clinical use of a slow maxillary expander with Ni–Ti springs appears efficient and safe in in the correction of maxillary hypoplasia during mixed dentition.

Immediate placement of single implants with or without immediate provisionalization in the maxillary aesthetic region: A 5-year comparative study.

AimTo compare marginal bone level changes around immediately placed and immediately provisionalized implants with immediately placed and delayed provisionalized implants in the aesthetic region after five years of function.Materials and MethodsForty patients with a failing tooth in the maxillary anterior region were randomly assigned immediate implant placement with immediate (Group A: n = 20) or delayed (Group B: n = 20) provisionalization. Definitive crown placement occurred three months after provisionalization. The primary outcomes were changes in marginal bone level. In addition, survival rates, buccal bone thickness, soft peri‐implant tissues, aesthetics and patient‐reported outcomes were assessed.ResultsAfter 5 years, the mean mesial and distal marginal bone level changes were 0.71 ± 0.68 mm and 0.71 ± 0.71 mm, respectively, in group A and 0.49 ± 0.52 mm and 0.54 ± 0.64 mm, respectively, in group B; the difference between the groups was not significant (p = .305 and p = .477, respectively). Implant and restoration survivals were 100%. No clinically relevant differences in buccal bone thickness or in mid‐facial peri‐implant mucosal level, aesthetic and patient outcomes were observed.ConclusionsThe mean marginal bone level changes following immediate implant placement and provisionalization were comparable with immediate implant placement and delayed provisionalization. (www.isrctn.com: ISRCTN57251089 and www.trialregister.nl: NL8255).

Buccal alveolar bone changes following rapid maxillary expansion and fixed appliance therapy.

To assess factors that may be associated with buccal bone changes adjacent to maxillary first molars after rapid maxillary expansion (RME) and fixed appliance therapy. Pretreatment (T1) and posttreatment (T2) cone-beam computed tomography scans were obtained from 45 patients treated with RME and preadjusted edgewise appliances. Buccal alveolar bone thickness was measured adjacent to the mesiobuccal root of the maxillary first molar 4 mm, 6 mm, and 8 mm apical to the cementoenamel junction, and anatomic defects were recorded. Paired and unpaired t-tests were used to compare alveolar bone thickness at T1 and T2 and to determine whether teeth with posttreatment anatomic defects had thinner initial bone. Correlation analyses were used to examine relationships between buccal alveolar bone thickness changes and amount of expansion, initial bone thickness, age at T1, postexpansion retention time, and treatment time. There was a statistically significant reduction in buccal alveolar bone thickness from T1 to T2. Approximately half (47.7%) of the teeth developed anatomic defects from T1 to T2. These teeth had significantly thinner buccal bone at T1. Reduction in alveolar bone thickness was correlated with only one tested variable: initial bone thickness. RME and fixed-appliance therapy can be associated with significant reduction in buccal alveolar bone thickness and an increase in anatomic defects adjacent to the expander anchor teeth. Anchor teeth with greater initial buccal bone thickness have less reduction in buccal bone thickness and are less likely to develop posttreatment anatomic defects of buccal bone.

Immediate implant placement with or without connective tissue graft: A systematic review and meta-analysis.

To assess the effect of connective tissue graft (CTG) in terms of vertical mid-facial soft tissue change when applied at the buccal aspect following single immediate implant placement (IIP). Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, EMBASE and Cochrane databases as well as a manual search to identify eligible clinical studies up to January 2020. Randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP with CTG and without CTG over a mean follow-up of at least 12months were included for a qualitative analysis. Meta-analyses were performed on data provided by RCTs. Out of 1814 records, 5 RCTs and 3 NRSs reported on 409 (IIP + CTG: 246, IIP: 163) immediately installed implants with a mean follow-up ranging from 12 to 108months. Only 1 RCT showed low risk of bias. Meta-analysis revealed a significant difference in terms of vertical mid-facial soft tissue change between IIP + CTG and IIP pointing to 0.41mm (95% CI [0.21; 0.61], p<.001) in favour of soft tissue grafting. This outcome was clinically relevant since the risk for ≥1mm asymmetry in mid-facial vertical soft tissue level was 12 times (RR 12.10, 95% CI [2.57; 56.91], p=.002) lower following IIP + CTG. Soft tissue grafting also resulted in a trend towards less bleeding on probing (MD 17%, 95% CI [-35%; 1%], p=.06). Meta-analyses did not reveal significant differences in terms of pink aesthetic score, marginal bone level change and probing depth. Results were inconclusive for horizontal mid-facial soft tissue change and papilla height change. Based on GRADE guidelines, a moderate recommendation for the use of a CTG following IIP can be made. CTG contributes to mid-facial soft tissue stability following IIP. Therefore, CTG should be considered when elevated risk for mid-facial recession is expected in the aesthetic zone (thin gingival biotype, <0.5mm buccal bone thickness).

Evaluation of immediate implant in patients with limited buccal bone wall dehiscence in single upper anterior tooth

Objective: To compare and evaluate the clinical outcome of immediate implant therapy in patients with limited buccal bone wall dehiscence and in patients with intact buccal bone wall. Methods: This prospective cohort study included patients intended to receive immediate implant treatment in upper anterior esthetic region in the Department of Implantology, Hospital of Stomatology, Wuhan University from August to December, 2018. Patients with buccal bone wall dehiscence limited to the coronal half were attributed to experimental group to conduct flap implant surgery (indicating to less than coronal half of the buccal bone wall length from the alveolar bone crest to the implant tip), whereas patients with intact buccal bone wall were attributed to control group to conduct flapless implant surgery. Buccal bone wall resorptions in height and thickness were evaluated 6 months after implant placement. Implant survival rate, pink/white esthetic score and post-operation complications were also analyzed 12 months after implant placement. Paired t-test and two-sample t-test were adopted to analyze the differences of different points within one group and differences between groups, respectively. Results: A total of 38 patients with the age of (39.2±5.8) years (range 19-45 years) and 38 upper anterior single tooth implants were included,in which 19 patients were attributed to experimental group [12 male and 7 female, the age was (37.6±5.3) years], and 19 patients were attributed to control group [9 male and 10 female, the age was (40.8±6.7) years]. Over the 12 months' observation after implant placement, the overall implant survival rate was 97% (37/38), and 18/19 in control group and 19/19 in experimental group. Only one implant lost in control group and no other complications were reported. Buccal bone resorption in thickness and height occurred in both groups within 6 months after implant placement. The thickness and height of buccal bone decreased significantly in both groups within 6 months after implant placement (P<0.05). Thickness decreases in experimental group were (1.32±0.74), (0.53±0.89) and (0.36±0.70) mm in coronal, middle and apical part of implant in experimental, and (1.24±0.57), (0.83±0.46) and (0.38±0.72) mm in coronal, middle and apical part of implant in control group. While the buccal bone height decreases were (0.24±0.15) mm in experimental group and (0.25±0.23) mm in control group. There were no statistical differences between the corresponding spots in the two groups (P>0.05). Upon the final restoration, both group got ideal pink esthetic scores [experimental group (10.92±1.13),control group (10.92±1.26)] and white esthetic scores [experimental group (7.61±0.78), control group (7.40±0.71)], the differences in both groups were not statistically significant (P>0.05). Conclusions: Clinical results of immediate implant to patients with buccal bone wall dehiscence limited to the coronal half are comparable to the results of patients with intact buccal bone wall.

Relationship between buccal alveolar bone thickness and crown-to-root dimensions around mandibular first and second molars: A cone-beam-computed tomography-based study.

Assessment of buccal alveolar bone thickness (ABT) and crown-to-root dimensions are essential in implant density; therefore, three-dimensional evaluation of these parameters provides a superior visualization than conventional radiographs. The present cross-sectional cohort study aims to investigate the relationship between buccal ABT and crown-to-root dimensions around the mandibular first and second molars using cone-beam-computed tomography (CBCT). Initially, CBCT-based scans from 271 individuals were assessed. Based on the inclusion and exclusion criteria, 171 CBCT-based scans were excluded. In total, 100 CBCT-scans were included in the present investigation and processed for data extraction. On the mandibular first and second molars, the mesial and distal root lengths and mesiodistal diameter of the crowns were measured. The pulpal floor served as a reference point for assessment of root length. The buccal ABT was measured at the coronal, middle and apical one-third of the root. Statistical analysis was performed and the level of significance was set at P< 0.01. One-hundred CBCT-scans from 294 mandibular teeth (137 first molars and 157 second molars) were included. One hundred and eighty-nine and 105 teeth were from males and females, respectively. The normality plot showed a normal data distribution. The mesiodistal crown width showed a weak yet significant correlation with mesial root length (r= 0.137), bone thickness at mesial apical third (r= 0.180), distal apical (r= 0.157) and distal coronal third (r= 0.161). Bone thickness at mesial, middle and apical third correlated significantly with one other (r= 0.786). There is a direct correlation between the buccal ABT and tooth dimensions around the mandibular first and second molars.