Alveolar Bone Thickness Research Articles

Safe regions of miniscrew implantation for distalization of mandibular dentition with CBCT

BackgroundTo assess the anatomy of the mandibular buccal shelf (MBS) with cone-beam computed tomography (CBCT) and to identify the region of miniscrew implantation for the distalization of mandibular dentition.Materials and methodsThe MBS was assessed in 80 patients at four regions as follows: (i) between the buccal root of the mandibular second premolar and the mesiobuccal root of the first molar (L5b–L6mb), (ii) between the mesiodistal root of the first molar (L6mb–L6db), (iii) between the distobuccal root of the first molar and the mesiobuccal root of the second molar (L6db–L7mb), and (iv) between the mesiodistal roots of the second molar (L7mb–L7db). The buccal alveolar bone thickness, the narrowest inter-radicular space at the buccal side of the roots, and the distance between the implantation site and the mandibular neural tube were measured at horizontal planes of 3, 5, 7, and 9 mm from the alveolar crest.ResultsThe buccal alveolar bone thickness increased from the premolar to the molar and from the crest edge to the mandibular roots. The L7mb–L7db region had the thickest buccal alveolar bone of 7.61 mm at a plane of 9 mm. The buccal inter-radicular spaces were smallest in the L7mb–L7db region and greatest in the L6db–L7mb region. The distances from the implantation site to the mandibular neural tube at planes of 3, 5, 7, and 9 mm were all > 13 mm from the L6 region to the L7 region.ConclusionsThe L6db–L7mb region should be the first choice for miniscrew implantation in the MBS for the distalization of mandibular dentition.

Geometric analysis of alveolar bone around the incisors after anterior retraction following premolar extraction.

To evaluate changes in shape and alterations in thickness and vertical marginal bone levels of the alveolar bone around the maxillary and mandibular incisors before and after orthodontic treatment with premolar extraction using geometric morphometric analysis. Thirty-six patients with Class I bialveolar protrusion who underwent orthodontic treatment with premolar extraction were included. Cone-beam computed tomographic scans were obtained from the patients before and after treatment. Five fixed landmarks and 70 semilandmarks were used to represent the morphology of the alveolar bone around the maxillary and mandibular incisors. The coordinates of the landmarks of the alveolar bones were generated by Procrustes fit. The labial and lingual alveolar bone thicknesses around the maxillary and mandibular incisors and vertical marginal bone level were assessed quantitatively. There was a significant difference in shape change of the alveolar bone before and after treatment. The deformation grid of the thin plate spline showed that the thickness and vertical marginal bone decreased on the lingual side after treatment. Shape changes were greater for the lingual alveolar bone on the mandibular incisor than for the maxillary incisors. Orthodontic treatment with premolar extraction might cause loss of alveolar bone around the maxillary and mandibular incisors. Careful consideration is needed to avoid iatrogenic degeneration of periodontal support around the incisors, particularly in the lingual area.

Cone-beam CT analysis on the treatment efficacy in the vertically impacted maxillary central incisors

Objective: To analyze the treatment efficacy in the vertically impacted maxillary central incisors using cone-beam CT (CBCT) and explore the treatment timing and the influence of orthodontic traction on the root development and alveolar bone height in the mixed dentition. Methods: Twenty-two patients with vertically impacted maxillary central incisor who were admitted to the Department of Orthodontics, Stomatological Hospital affiliated to Nanjing Medical University from December 2012 to December 2017 were selected [12 males and 10 females, (9.2±0.9) years]. Based on the dental age, patients were classified as early treatment group (teeth ranging from a third to two thirds of root formation, n=12) and late treatment group (teeth with nearly or fully complete root formation, n=10). The contralateral maxillary central incisor was used as the control. Three-dimensional reconstruction of CBCT before treatment, after treatment and one year after treatment was carried out to measure root length, tooth surface area, tooth volume, labial and lingual apical alveolar bone thickness, the loss of labial alveolar bone height and intraosseous root ratio. The clinical crown length was measured in the mouth. The difference values of the measurement variables between the impacted teeth and the control teeth were calculated and analyzed(measurement values of impacted teeth were subtracted from control values). Results: The values of root length difference beween the impacted teeth and the control teeth in the early and late treatment group were (1.58±1.56) mm and (2.57±1.00) mm, respectively after the treatment and the values were significantly less than those corresponding values before treatment [(3.47±1.40) and (3.36±0.79) mm] (P<0.05). After the treatment, the values of the surface area and volume difference between the impacted teeth and the control teeth in the early treatment group [(0±34) mm(2) and (-10±44) mm(3)] were significantly less than those corresponding values before treatment [(38±31) mm(2) and (55±70) mm(3)] (P<0.05). The value differences of any measurement variables between the early and late treatment group were not significantly different after the treatment (P>0.05). The root length and intraosseous root ratio of the impacted teeth after the treatment in the early and late treatment group were significantly less than those of the control teeth after the treatment (P<0.05). The clinical crown length, the loss of labial alveolar bone height of the impacted teeth after the treatment were significantly larger than those of the control teeth after the treatment (P<0.05). Conclusions: Orthodontic traction promoted the root growth and development of the vertically impacted maxillary central incisors. However, the root length and alveolar bone height still cannot reach the normal level after treatment. Treatment timing had no effect on root development and alveolar bone height of vertically impacted maxillary central incisors in mixed dentition.

Evaluation of Vestibular Bone Thickness in Class I Malocclusion Treatment With Corticotomy-Assisted Rapid Orthodontics.

Corticotomy-assisted rapid orthodontics is a widely used method for speeding up conventional orthodontics. This study (i) evaluates the effects of corticotomy alone, corticotomy combined with bone graft, and corticotomy with platelet-rich fibrin (PRF) on vestibular alveolar bone thickness in patients with class I malocclusion; (ii) compares the treatment time with a conventional orthodontic therapy group, and (iii) investigates the periodontal health of patients who have undergone corticotomy-assisted rapid orthodontics. The patients were divided into 3 groups: Group 1 (n = 10) underwent corticotomy alone; Group 2 (n = 10) underwent corticotomy combined with bone graft, and Group 3 (n = 10) underwent corticotomy combined with PRF. In the following stage, vestibular alveolar bone thicknesses were evaluated using 3-dimensional cone-beam computed tomography images. The findings showed that Group 2 achieved a more significant augmentation of the vestibular alveolar bone than Groups 1 and 3 (P = 0.001, P = 0.003), while corticotomy-assisted rapid orthodontics decreased treatment times. Sufficient alveolar bone thickness and preservation of the periodontal health were achieved when the corticotomy procedure was either combined with a bone graft or with PRF in the Class-I malocclusion patients. Bone grafts provided better bone thickness at the buccal surface of the anterior teeth of the mandible and maxilla, whereas the thickness of the keratinized gingiva was better with PRF.

Dehiscence and fenestration in anterior teeth : Comparison before and after orthodontic treatment.

Previous studies have reported incidence rates of dehiscence (DEH) and fenestration (FEN) as high as 36.51 and 51.09%, respectively. Only afew studies comparing DEH and FEN before and after orthodontic treatment (OT) are available in the literature. The aim of this study was to evaluate the occurrence of DEH and FEN in anterior teeth, before and after OT, using cone-beam computed tomography (CBCT). In addition, findings may provide aclinical basis for avoiding DEH and FEN during therapeutic tooth alignment. CBCT images of 21patients near the end of their peak growth and development were included. DEH and FEN in the anterior teeth and thicknesses of the alveolar bone at the palatal (TP) and labiolingual (LL) sides of each anterior tooth were measured before and after OT. After OT, the incidence rates of mandibular anterior labial DEH, maxillary anterior TP-bone defect, and mandibular anterior lingual bone defect were increased by 20, 19, and 30%, respectively. Assessment of CT images prior to treatment showed that the teeth developing bone defects were significantly different regarding the apical alveolar bone thicknesses compared to the teeth that did not develop bone defects after OT, i.e., the incidence of DEH and FEN after OT was lower if the thickness of the apex to labiolingual alveolar bone before OT was as follows: the apex to labial alveolar bone thickness of the maxillary central incisor and maxillary lateral incisor was >4 mm, the apex to palatal alveolar bone thickness of the maxillary lateral incisor was >3 mm; the apex to labiolingual alveolar bone thickness of the lower incisor was >5 mm. The incidence of post-OT DEH at the maxillary anterior and mandibular anterior lingual surfaces were increased significantly compared to before treatment. In general, the smaller the apex to labiolingual alveolar bone thickness, the greater the likelihood of bone defects occurring after OT. Evaluation of the apical position of anterior teeth in alveolar bone can help minimize the occurrence of bone defects after OT.

Effects of Leukocyte-Platelet-Rich Plasma on the Alveolar Bone Changes During Orthodontic Tooth Movement in Rabbits: A Micro-CT Study

Objective: To investigate the effects of leukocyte-platelet-rich plasma (L-PRP) on the alveolar bone changes at the compression and tension sides during orthodontic tooth movement. Materials and Methods: Around 20 New Zealand white rabbits were used in a split-mouth design. The maxillary first premolar was moved mesially with a nickel-titanium closed-coil spring. One side of the maxilla was randomly injected with L-PRP, while the contralateral side served as the control which received normal saline. The alveolar bone adjacent to the maxillary first premolar was scanned using microcomputed tomography at days 0, 7, 14, and 28. Microstructural parameters including bone volume fraction, trabecular thickness, and trabecular separation of alveolar bone were assessed on the compression and tension sides of the maxillary first premolar. Results: Compared between the groups, the L-PPR group showed a significantly decreased bone volume fraction on the compression side on days 7 and 14 but significantly increased bone volume fraction on the tension side on day 14. However, there were no statistically significant differences in the parameters of trabecular thickness and trabecular separation. Conclusion: Local administration of L-PRP may promote bone resorption on the compression side and bone formation on the tension side at the initial stage of orthodontic tooth movement.

Measurement of the bone height of mandibular incisors and canines on computed tomography-Limitations according to bone thickness.

To verify the correlation between cone beam CT (CBCT) and spiral CT (SCT) images and direct measurement of the bone height and to verify whether bone thickness (BT) influences the accuracy of bone height measurement on CT. One hundred and fourteen measurements were obtained in 10 dry human mandibles. The alveolar bone height was measured on volumetric and linear images. Negative, average and significant correlations (-0.622** to -0.489**) were verified between BT and the absolute error. When the alveolar bone thickness was at least 0.6mm, the mean differences were 0.16 and 0.28mm on linear images and 0.12 and 0.03mm on volumetric images for CBCT and SCT. Additionally, these values ranged from -0.46 to 0.79 and -0.32 to 0.88mm on linear images and from -0.64 to 0.67 and -0.57 to 0.62mm on volumetric images for CBCT and SCT. When the alveolar bone thickness was less than 0.6mm, the CT evaluation varied from -1.74 to 5.42 and -1.64 to 5.42mm on linear images and from -3.70 to 4.28mm and -3.49 to 4.25mm on volumetric images for CBCT and SCT. Spiral CT and CBCT images demonstrate significant correlation with direct measurement for the alveolar bone height. Measurement of the alveolar bone labial and lingual to the mandibular incisors and canines presented higher accuracy when its thickness was greater than 0.6mm. When the thickness was less than 0.6mm, bone dehiscence can be diagnosed despite bone being clinically present.

A Cone-Beam Computed Tomographic Study of Alveolar Bone Morphology in Patients With Unilateral Cleft Lip and Palate.

To evaluate the bony support around the teeth adjacent to the unilateral cleft lip and palate (ULCLP) using cone-beam computed tomography. Cone-beam computed tomographies of 48 cleft-adjacent teeth (28 anterior and 20 posterior to the cleft) and 48 noncleft control teeth were evaluated. The alveolar bone thickness at 3 and 6 mm apical to the cement-enamel junction (CEJ), the distance between the alveolar crest and CEJ (Alv-CEJ), and the presence of fenestration were assessed in buccal, palatal, and proximal surfaces. The alveolar bone on the buccal and palatal sides of the teeth anterior to the cleft was significantly thinner than the noncleft teeth (all P < .05). The Alv-CEJ was significantly greater on the buccal and distal surfaces of the teeth anterior to the cleft (P < .001 and P = .010, respectively) and on the palatal and mesial surfaces of the teeth posterior to the cleft (P = .024 and P = .003, respectively) when compared to the noncleft teeth. The frequency of reduced alveolar bone height (>2 mm) was higher than noncleft side for buccal and distal sides of the teeth anterior to the cleft (P = .016 and .006, respectively) and the buccal and mesial sides of the teeth posterior to the cleft (P = .008 and <.001, respectively). The teeth anterior to the cleft had a higher prevalence of fenestration (P = .004). Reduced alveolar bone height is more common in the cleft side compared to the control side. The teeth anterior to the ULCLP have thinner alveolar bone support and higher frequency of fenestration.

Analysis of whether or not the alveolar palatine bone thickness of the central incisors is sufficient for implants of 3 mm and 3.5 mm thickness using Cone-Beam Computed Tomography

Objective: The purpose of this study was to investigate the alveloar palatine bone thickness of the maxillary central incisors using cone-beam computed tomography (CBCT).&#x0D; Material and Methods: This study used the CBCT images of 480 patients (240 male – 240 female). In order to determine bone thickness, measurements were made on the program perpendicularly to the long axis of the tooth at 3 points selected from the 3, 6 and 9 mm apical or the enamel-cement border in parallel to the long axis of the central teeth.&#x0D; Results: For the left central teeth, the mean palatine bone thickness was found for the coronal, medial and apical regions as 1.48 mm, 3.09 mm and 5.13 mm, respectively, while these values were respectively 1.35 mm, 2.95 mm and 5.10 mm for the right side.&#x0D; Conclusion: Considering that there should be a bone of at least 1 mm thickness on socket walls for immediate implantation, it was determined that palatine bone thickness is not sufficient by itself for immediate implantation. As a result of the analysis, it was seen that the palatine alveloar bone thickness that was observed in women was thinner than that in men.&#x0D; &#x0D; How to cite this article: Üner DD, İzol BS. Analysis of whether or not the alveloar palatine bone thickness of the central incisors is sufficient for implants of 3 mm and 3.5 mm thickness using cone-beam computed tomography. Int Dent Res 2019;9(2):51-7.&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Molar inclination and surrounding alveolar bone change relative to the design of bone-borne maxillary expanders: A CBCT study.

To evaluate the molar inclination and skeletal and alveolar bone changes when comparing tooth bone-borne (MSE) and tissue bone-borne type maxillary expanders (C-expander) using cone-beam computed tomography (CBCT) in late adolescence. A sample of 48 late-adolescent patients were divided into two groups according to the type of expander: MSE group (n = 24, age = 19.2 ± 5.9 years) and C-expander group (n = 24, age = 18.1 ± 4.5 years). CBCT scans were taken before treatment and 3 months after expansion. Transverse skeletal and dental expansion, alveolar inclination, tooth axis, buccal alveolar bone height, thickness, dehiscence, and fenestration were evaluated on the maxillary first molar. Paired t-test, independent t-test, Pearson's chi-square test, and Spearman correlation analysis were performed. The MSE group produced greater dental expansion (P < .05), whereas skeletal expansion was similar in both groups (P = .859). The C expander group had more alveolar bone inclination change (P < .01), and the MSE group had more buccal tipping of the anchorage teeth (P < .01 or .001). Buccal alveolar bone height loss and thickness changes were greater in the MSE group (P < .01 or <.001). Formation of dehiscences was more frequent in the MSE group (P < .001), whereas for fenestrations, there were no significant differences between the two groups. Buccal bone height loss in the MSE group had a negative correlation with initial buccal bone thickness. The incorporation of teeth into bone-borne expanders resulted in an increase in the severity of side effects. For patients in late adolescence, tissue bone-borne expanders offer comparable skeletal effects to tooth bone-borne expanders, with fewer dentoalveolar side effects.

Clinical assessment of the palatal alveolar bone thickness and its correlation with the buccolingual angulation of maxillary incisors for immediate implant placement.

Clinicians needed to be aware of the thinness of the palatal bone plate when identifying severe protrusion of maxillary incisors, as this could result in perforation of the palatal bone plate during surgical procedures associated with immediate maxillary implant placement. This study evaluated the thickness of the palatal bone plate, the buccolingual angulation of maxillary incisors, and the correlation between these two parameters in relation to immediate implant placement. Cone-beam computed tomography images of 37 Asian patients (20-60 years old) with no evidence of dental treatment in the maxillary incisor area were collected and classified into groups based on sex and incisor locations. Sagittal slices were used to measure the palatal bone plate thickness at the cervical, middle, and apical levels, and the buccolingual angulation of each tooth was also measured. The intraclass correlation, Shapiro-Wilk test, descriptive analysis, Student's t-test, and Pearson correlation were used for statistical and correlation analyses, with P < .05 applied as the criterion for statistical significance. At the apical level of all inspected teeth and the middle level of lateral incisors, the palatal bone was significantly thicker in males than in females. The inclination of the maxillary lateral incisor showed a moderate negative linear correlation with the palatal bone thickness at the apical level (R = -0.517 and R = -0.579 for males and females, respectively). In an Asian population, an increased buccolingual angulation of the maxillary lateral incisors was correlated with a thinner palatal bone plate at the apical level.

The dimensions of the facial alveolar bone at tooth sites with local pathologies: a retrospective cone-beam CT analysis.

To assess the impact of various local pathologies on facial alveolar bone dimensions at tooth sites. Cone-beam computed tomography images of 60 patients were analyzed. Healthy teeth and teeth with local pathologies (i.e., endodontically treated, periodontally diseased teeth, and teeth with periapical lesions) were included. The thickness of the facial alveolar bone was measured at five locations: (1) the bone crest (W0), (2) 25% (W25), (3) 50% (W50), (4) 75% (W75) of the distance from the bone crest to the root apex (A), and (5) in the A region (W100). The results were considered statistically significant at p < 0.0008 (adjustment according to the statistical correction for multiple testing). A total of 1174 teeth (707 healthy and 467 with the local pathologies) were assessed. Periodontally diseased maxillary premolars and anterior teeth in the mandible in the W0 position, as well as maxillary molars in the W25 position, tended to have a lower facial bone thickness when compared to the healthy teeth (0.68mm vs. 0.84mm, p = 0.008; 0.47mm vs. 0.55mm, p = 0.004; and 1.27mm vs. 1.72mm; p = 0.009, respectively). In contrast, the observed tendency pointed towards thicker facial bone wall for the periodontally diseased mandibular anterior teeth in the W50 position (0.74 vs. 0.52, p = 0.001). Healthy maxillary molars tended to display a thicker facial alveolar bone compared to the teeth with local pathologies in the W25, W50, and W75 positions (p = 0.001, p = 0.005, and p = 0.004, respectively). The present analysis has indicated that local pathologies are commonly associated with a compromised socket morphology. The facial bone thickness was particularly reduced at periodontally diseased teeth, which may challenge implant therapy.

Analysis of the Buccal Bone Plate, Root Inclination and Alveolar Bone Dimensions in the Jawbone. A Descriptive Study Using Cone-Beam Computed Tomography.

ABSTRACTObjectivesThis study aims to determine if there are enough buccal alveolar bone thickness to perform an immediate dental implant placement in anterior and posterior maxillary teeth.Material and MethodsA total of 1463 teeth were examined, from 202 cone-beam computed tomography scans with voxel sizes of 0.15 mm. On each tooth, the following measures were determined: the alveolar bone thickness in two locations; the vertical distance between the buccal alveolar crest and cementoenamel junction; the angle between the tooth’s long axis and the alveolar bone axial inclination in the sagittal plane.ResultsIn the most coronal location of maxillary teeth, the thickness of alveolar bone was lower than 0.6 (SD 0.6) mm in 50% of the teeth, and in the middle of the root the bone thickness was, on average, 0.96 (SD 0.6) mm. For the same maxillary teeth, the vertical distance between the buccal alveolar crest and cementoenamel junction and the angulation measured were, on average, 3.6 (SD 1.2) mm and 12.1º (SD 1.4º), respectively.ConclusionsThe present study revealed that in most cases the thickness of buccal alveolar bone was less than 1 mm. Consequently, in such cases, immediate dental implant placement operation is not recommended, or should be combined with bone regeneration techniques.

Influence of vertical skeletal pattern on cortical and alveolar bone thickness and root spacing in the anterior maxilla assessed by cone beam computed tomography

PurposeThe aim of this study was to evaluate the dimensional properties of bone in the anterior maxilla in patients with different vertical skeletal patterns in order to ensure safe placement of temporary anchorage devices. Materials and methodsFifty-one CBCT images were divided into three equal groups according to vertical skeletal pattern, based on palatal plane to mandibular plane angle. Cortical bone thickness, alveolar bone thickness and interdental root distance were measured between the teeth in the anterior maxilla at 6 mm and 8 mm apical to the interdental cementoenamel junction. ResultsCortical bone thickness was significantly different among vertical groups at some sites. Hyper-divergent subjects had thinner cortical bone than hypo-divergent and normo-divergent subjects. All three groups, in the anterior maxilla, cortical bone thickness tended to increase from between central incisors (U1–U1) to between lateral incisor and canine (U2–U3). Alveolar bone thickness was greatest between central and lateral incisors (U1–U2), and the thinnest alveolar bone was at U1–U1 area. Average interdental root distance ranged from 1.33 ± 0.48 mm to 3.43 ± 1.25 mm. The largest and smallest interdental root distances were at U1–U1 and U1–U2 sites, respectively. ConclusionPlacement of TADs in hyper-divergent subjects should be performed with caution. The suitable site for TADs in the anterior maxilla was between the lateral incisor and canine in all vertical skeletal patterns.

Buccal alveolar bone thickness changes after rapid maxillary expansion with tooth-borne and bone-borne expanders

Buccal alveolar bone thickness changes after rapid maxillary expansion with tooth-borne and bone-borne expanders

Three-dimensional evaluation of labial alveolar bone overlying the maxillary and mandibular incisors in different skeletal classifications of malocclusion

The purpose of this study was to investigate differences in the thickness of the labial bone overlying the maxillary and mandibular incisors in class I, II, and III skeletal classifications using three-dimensional cone-beam computed tomographs (CBCT) technology. Pretreatment CBCTs of 54 Caucasian subjects (44 males, 10 females) were collected from the archives of a graduate orthodontic clinic. The subjects were divided into three groups based on their skeletal classification. CBCT scans were oriented to the long axis of each maxillary and mandibular incisor from the root apex to incisal tip and the axial inclination of each incisor was measured and recorded. Labial bone thickness was measured at the apex (A) and at the midpoint (MP) on each maxillary and mandibular incisor. A linear measurement, perpendicular to the long axis, was recorded from the labial bone surface to the most anterior root surface at two points. The effects of skeletal classification, jaw, incisor position, and side on A, MP, and Inclination were evaluated using mixed-model ANOVA. A 5% significance level was used for all tests. Significantly greater bone thickness at the apex and midpoint was reported in class III individuals than class I or II. Central incisors had significantly greater bone thickness at both the root apex and midpoint. Significantly greater bone thickness was noted in the mandible at the level of the apex. At the level of the midpoint, significantly greater thickness was reported in the maxilla. There was a positive correlation between thickness and angle within each jaw-incisor combination for class I patients and for central incisors in class III patients. The thickness of labial alveolar bone over the incisors varies based on the underlying skeletal discrepancy in each patient. Skeletal discrepancy influences the inclination of the maxillary and mandibular incisors.

Alveolar bone plate measurements of maxillary anterior teeth: A retrospective Cone Beam Computed Tomography study, AlMadianh, Saudi Arabia

PurposeTo study bone profile (facial bone thickness and height of alveolar bone crest) of anterior maxillary teeth in the aesthetic area among Saudi dentulous adults. MethodsThis retrospective study was conducted at Taibah University College of Dentistry and Hospital, AlMadinah; Saudi Arabia. The analysis included 490 adult patients’ Cone Beam Computed Tomography (CBCT) retrieved from Kodak Carestream-R4 database. Alveolar bone thicknesses and crest bone-height for maxillary anterior teeth were measured directly on CBCT images using built-in digital caliper. Descriptive statistics and comparative analysis were performed. ResultsOf the 490 CBCTs 186 were found useable for the study purpose. The mean age of the patients was 34.65 ± 11.57and 109 (59%) were males. Statistically significant (P < 0.001) differences were found between the mean ± SD facial plate thickness of the central incisors, lateral incisors, and canines (1.12 ± 0.28 mm, 1.14 ± 0.31 mm, and 1.03 ± 0.24 mm, respectively). In addition, facial plate height increased statistically significantly positively with age for the central incisors, lateral incisors, and canines (r = 0.543, n = 186, p = 0.001; r = 0.515, n = 186, p = 0.001; r = 0.474, n = 186, p = 0.001, respectively). Genderwise, males had statistically significantly (P < 0.00) higher facial bone thickness e.g. in central incisor (males 1.20 ± 0.29 VS females 1.04 ± 0.25, p = 0.001) and increased bone height (Males 2.62 ± 0.77VS females 2.09 ± 0.66, p = 0.001) compared to females. ConclusionIn this study, the significant differences in bone thickness and crest height between anterior maxillary teeth in the aesthetic area was highlighted. Notably, increases in facial plate crest height was linked to age and male and female differed on both facial bone thickness and bone height.

Relationship between alveolar bone thickness, tooth root morphology, and sagittal skeletal pattern : A cone beam computed tomography study.

The goal of this work was to examine the relationship between sagittal facial pattern and thickness of alveolar bone in conjunction with root morphology of teeth by using cone beam computed tomography (CBCT). The study was carried out on the CBCT scans from 3group of patients (n = 20 in each group). The first group involved skeletal class1, the second group involved skeletal class2, and the third group involved skeletal class3 patients. In all, 14permanent teeth and interdental regions in the maxilla and mandible were evaluated. Root length and root width were measured on each tooth. Buccal cortical bone thickness, cancellous bone thickness, and lingual cortical bone thicknesses were measured in each interdental region. Analysis of variance, Kruskall-WallisH and Mann-WhitneyU tests were used for statistical comparisons. No significant difference was found between the groups for root length, root width, buccal cortical bone and lingual cortical bone thickness. A significant difference was observed between the groups for cancellous bone thickness as it was thicker in skeletal class2 group. Cortical bone was thicker in the mandible compared to maxilla on both buccal and lingual sides and it was thicker in the posterior region compared to the anterior region on the buccal side. Differences in cancellous bone thickness between different sagittal facial patterns and differences in cortical bone thickness between different alveolar regions should be taken into consideration when planning orthodontic tooth movements and anchorage mechanics.

Diş eti fenotipi ve alveolar kemik morfolojisi arasındaki ilişkinin değerlendirilmesi

Objective In recent years, the determination of gingival phenotype has gained importance in the field of dentistry. Bone and gingival relationship may directly affect the success rate of treatment modalities. The aim of this study is to evaluate the relationship between gingival phenotype and underlying alveolar bone thickness. Methods In this study, we investigated the relationship between the clinical periodontal parameters and gingival phenotypes on the cone beam computed tomography (CBCT) image taken in the last 3 months of a total of 207 teeth. The gingival phenotype was identified as “thin” / “medium” / “thick” with the newly developed Hu-Friedy Colorvue ® phenotype probe. Clinical periodontal parameters, width of keratinized tissue and gingival recession values were recorded. Buccal bone thickness was measured at three points, as crestal 1, 2 and 4 mm. on CBCT images. Results According to the results, in thin phenotype, width of keratinized gingiva and bone thickness at three levels was found significantly lower than thick phenotype (p&amp;lt;0.016). In medium phenotype bone thickness at crestal 2 and 4 mm were found to be significantly less than the thick phenotype (p&amp;lt;0.016). Additionally a negative correlation was seen between gingival recession and bone thickness at crestal 2 and 4 mm levels (p&amp;lt;0.05). Conclusions We observed that there was a significant positive correlation between the gingival phenotype and buccal alveolar bone thickness. We suggest that the amount of bone thickness may be effective on ginigval recession.

Comparative study of alveolar bone remodeling around the upper incisor area after Twin-block and high-pull headgear-activator functional orthopedic therapy

The aim of this clinical study was to evaluate the changes of alveolar bone morphology around the upper incisors before and after functional treatment in adolescents using cone-beam CT(CBCT). Thirty patients with skeletal Class II mandibular retrusion who were successfully treated with high-pull headgear-activator(HGAC) and Twin-block were selected and divided into 2 groups (HGAC and Twin-block groups), 15 in each group. CBCT was performed before and after treatment, to observe upper incisor movement in the alveolar bone and alveolar bone remodeling. Statistical analysis was performed using SPSS 20.0 software package to analyze the changes of alveolar bone thickness, angle of central incisor and alveolar bone before and after treatment. Horizontally, the edge of the maxillary incisor appeared lingual movement in both groups, while the root apex appeared lingual movement in HGAC group and labial movement in Twin-block group. Vertically, the edge of the maxillary incisor was moved down and the root apex was moved up in all patients, whereas the moving distance was less in the edge and larger in the root apex in HGAC group. The thicknesses of major areas in the alveolar bone significantly increased in HGAC group, while in Twin-block group the labial thickness of the alveolar bone showed significant decrease and the palatal thickness showed significant increase. Moreover, the total thickness of the alveolar bone showed significant increase in both groups, yet Twin-block group showed more increase, and the angle of the alveolar bone showed more decrease in HGAC group. Both functional appliances can cause positive alveolar bone remodeling in maxillary incisor area. HGAC can achieve a controlled tilt inward movement of the maxillary incisors, intrude the incisors to a certain extent, and allow certain change in the bending angle of the incisor alveolar bone at the same time, which is conducive to improving ClassⅡcraniofacial pattern. Twin-block can tilt the maxillary incisor inward, suggesting that more attention needs to be paid to the control of the torque of the incisor when retracting anterior teeth in fixed orthodontic treatment after Twin-block functional treatment.