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@#It has been traditionally believed that a 1:1 cortical bone remodeling/tooth movement ratio has been preserved during orthodontic treatment for tooth movement, with the alveolar bone on the tension side growing and the alveolar bone on the pressure side resorbing to maintain the balance of the alveolar bone. However, recent studies have shown that alveolar bone loss has been found in patients who have undergone orthodontic treatment, suggesting that the alveolar bone does not change as the teeth change over time. Whether the morphology of the alveolar bone will change when the anterior teeth are moved has been the clinical focus. The changes of anterior alveolar bone in patients who have undergone tooth extraction after orthodontic treatment were summerized by literature review in this paper. The results of the review showed that the alveolar bone at the lingual/palatal root-cervical site of the anterior root is more prone to bone loss after extensive movement of the anterior teeth. With the development of imaging technology, CBCT is now more commonly used for analysis instead of two-dimensional images for measurement, as its results are more accurate. However, there are few multifactorial studies in which CBCT has been used to assess the morphological changes in the alveolar bone. The focus of future research is to compare the long-term changes in the anterior alveolar bone of patients of different ages based on three-dimensional imaging, and to study the correlation between different skeletal features, tooth movement patterns and alveolar bone remodeling.
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@#Introduction: Labial bone with adequate height and width is crucial for an implant to be successfully placed and ensure the stability of treatment outcome in the long term. The objective of this study was to employ cone-beam computed tomography (CBCT) assessment in evaluating the differences in labial alveolar bone morphology among the Kuantan population in Malaysia. Methods: A total of 60 images taken from Kulliyyah of Dentistry, International Islamic University Malaysia, between 2009 and 2019 were analysed. The root diameter, labial and palatal plate thickness, the labial bony curvature angle beneath the root apex, and the distance from the deepest point of labial bony curvature to the root apex were all measured on each of the maxillary anterior teeth. Results: At 3 mm below the cementoenamel junction, the mean (± standard deviation; SD) thickness of the labial plate for maxillary anterior teeth was 1.45 ± 0.62 mm, 1.38 ± 0.50 mm, and 1.61 ± 0.66 mm for the lateral incisor, central incisor, and canine, respectively. Below the root apex, the labial bony curvature angle was 233.63 ± 17.74 for the central incisor, 235.68 ± 17.74 for the lateral incisor and 233.81 ± 11.09 for the canine. Discussion: The result revealed a favourable labial plate in the Kuantan population when implant in the aesthetic zone is planned. Conclusion: Labial alveolar bone thickness of the Kuantan population was thin within 1.5 mm while the palatal plate was thick. Overall, labial alveolar bone was present within 3 mm below the cementoenamel junction. The labial bony curvature was highest and most curved for the central incisor compared to the lateral incisor and canine.
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Objective@#To investigate the features of alveolar bone morphology of mandibular central incisors in high-angle adult females using cone-beam computed tomography (CBCT) and evaluate the influence of aging in these patients.@*Methods@# CBCT and lateral cephalometric images of 142 untreated adult female patients were selected and grouped by facial growth pattern. The number of high-angle cases was increased to 164 to further explore the difference within high-angle adult females who were divided into two groups according to age. The indexes of alveolar bone height and thickness in the lower incisor region and inclination of the lower incisors were measured by Dolphin software. The data was statistically analyzed.@*Results@#Compared with the average-angle group, the high-angle group had a lower alveolar bone attachment level (P < 0.05) and less bone thickness at the root apex level (P < 0.05). The thickness of lingual alveolar bone decreased with labial inclination of the lower incisors in both the high-angle and average-angle groups (r = -0.251, P = 0.025; r = -0.428, P = 0.001, respectively). In hyperdivergent female patients, the middle-aged group had a lower attachment level of alveolar bone than the young group (P < 0.05), but no significant difference in bone thickness at the root apex level (P > 0.05) was found between the two groups@*Conclusion @# High-angle adult females had thinner mandibular anterior alveolar bone with significantly lower attachment levels. Aging and inclination of lower incisors influenced bone morphology and should be taken into careful consideration.
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@#As a minimally invasive procedure, micro-osteoperforations (MOPs) achieve desired therapeutic effect with minimal surgical intervention. The operation is relatively simple, and the effect of assisted orthodontic treatment is obvious. However, due to the lack of long-term follow-up studies, there is no unified consensus on the long-term stability of the procedure. This article reviews the research status of MOPs, biological and biomechanical mechanisms, clinical applications and limitations. MOPs can shorten orthodontic treatment time and accelerate tooth movement by exerting regional acceleratory phenomena (RAP). At the same time, this procedure will not damage the health of the periodontal tissue, and the postoperative bleeding and postoperative reaction are minor. In addition, the pain and discomfort of patients were relatively mild and acceptable. However, it also has limitations, mainly including the limited time of the RAP effect of MOPs. Although this procedure is a minimally invasive surgery, there is still a risk of treating regional bone defects. At present, it is still necessary to increase the sample size and extend the follow-up time to evaluate the long-term stability of MOPs.
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OBJECTIVES: Extraction of mandibular posterior teeth followed by immediate implant placement is considered as an optimal technique of immediate prosthetic rehabilitation. The analysis of alveolar bone dimensions with Cone Beam Computerized Tomography prior to implant placement is a prime determinant in treatment planning. Hence this preliminary study was conducted to analyze the alveolar bone dimensions in dentate mandibular posterior teeth to evaluate the available bone which can be utilized for immediate implant placements. MATERIALS AND METHODS: Retrospective data of 200 cases of full volume CBCT was procured from Riyadh Elm University (REU) database and reviewed for eligibility. Atotal of 10 cases were included in the study. Scans were assessed for thickness of buccal and lingual walls at 4mm below the CEJ (MP1) and at midroot level (MP2). Alveolar width was assessed at most coronal point on alveolar bone (BW1) and at superior border of mandibular canal (BW2). The height was be calculated by measuring the vertical distance between BW1 and BW2. Data was tabulated and statistically analyzed using unpaired t-test. RESULTS: The results of our study indicates that dimensions of buccal and lingual bone walls of all teeth at MP1 and MP2 in PM1, PM2 and M1 were statistically significant. Also only the 1st premolar (PM1) showed statistical significance with regard to dimensions at BW1 and BW2. CONCLUSION: The present study highlights the need for further studies with larger samples which can impact the immediate implant success rates in mandibular posterior teeth
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Objective@# To study the remodeling of alveolar bone after retraction of the maxillary incisors assisting with micro-implant anchorage in adult patients with maxillary protrusion by CBCT.@*Methods@#Forty patients who were treated with extraction of the maxillary first premolars with microimplant anchorage meeting the inclusion criteria were selected. The CBCT data before and after treatment were collected, and the Dolphin Imaging 3D measurement software was used to measure and analyze the height and thickness of the alveolar bone of the 80 upper central incisors and the 80 lateral incisors.@*Results @#After retraction of the incisors assisting with microimplant anchorage, the labial alveolar bone height of the maxillary central incisors decreased (0.11 ± 0.33) mm, and the lingual alveolar bone height of the maxillary central incisors decreased (0.85 ± 1.23) mm. The labial alveolar bone height of the maxillary lateral incisors decreased (0.18 ± 0.42) mm, and the lingual alveolar bone height of the maxillary lateral incisors decreased (1.13 ± 1.14 ) mm. The reduction in the lingual alveolar bone height was greater than that of the labial side, and the difference was statistically significant (P < 0.05). The labial alveolar bone thickness of the maxillary central incisors increased (the root cervix, the root media and the root apex), and the difference was statistically significant (P < 0.001). The labial alveolar bone thickness of the maxillary lateral incisors also increased (P < 0.05), while the lingual alveolar bone thickness and the total alveolar bone thickness of the maxillary central and lateral incisors decreased (P < 0.001). @*Conclusion@#In adults with maxillary protrusion, the microimplant was used to assist the reduction of the anterior teeth. The alveolar bone height of the maxillary incisors was reduced, and the palatal alveolar bone height decreased more than that of the labial side. The alveolar bone of the labrum was thickened, and the palatal alveolar bone thickness and the total alveolar bone thickness of the maxillary incisors were reduced after treatment.
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<p><b>OBJECTIVE</b>This study aimed to explore the relationship among gingival thickness (GT), underlying alveolar bone thickness (BT), and sagittal root position in the maxillary anterior measured by cone-beam computed tomography (CBCT). The theoretical foundation was applied to aesthetic dentistry, implant treatment planning, and therapeutic effect assessment.</p><p><b>METHODS</b>A total of 40 young volunteers with healthy periodontal status were involved in this research [16 males and 24 females aged 23-34 years with a mean age of (26.30±2.29) years]. Three records were measured by CBCT. GT was measured at the cemento-enamel junction level. Buccal BT was measured at three locations: 1, 3, and 5 mm below the alveolar crest, along the sagittal angle between the long axis of teeth, and along the long axis of the respective alveolar bone.</p><p><b>RESULTS</b>The average GT and alveolar BT thicknesses were (1.08±0.34) mm and (0.79±0.29) mm, respectively. The average angle between teeth and alveolar bone was 18.01°±8.96°. BT was positively associated with GT (r=0.293, P=0.001). The BT of canine was positively associated with the angle between teeth and alveolar bone (r=0.457, P=0.003).</p><p><b>CONCLUSIONS</b>BT was relatively thin. An angle was found between the long axis of teeth and that of the alveolar bone. BT was positively associated with GT. An accurate diagnosis of GT, underlying alveolar BT, and sagittal root position in the maxillary anterior is necessary before implant surgery to devise an appropriate implant treatment plan and achieve a predictable esthetic outcome.</p>
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OBJECTIVE: To assess the labial and lingual alveolar bone thickness in adults with maxillary central incisors of different inclination by cone-beam computed tomography (CBCT). METHODS: Ninety maxillary central incisors from 45 patients were divided into three groups based on the maxillary central incisors to palatal plane angle; lingual-inclined, normal, and labial-inclined. Reformatted CBCT images were used to measure the labial and lingual alveolar bone thickness (ABT) at intervals corresponding to every 1/10 of the root length. The sum of labial ABT and lingual ABT at the level of the root apex was used to calculate the total ABT (TABT). The number of teeth exhibiting alveolar fenestration and dehiscence in each group was also tallied. One-way analysis of variance and Tukey's honestly significant difference test were applied for statistical analysis. RESULTS: The labial ABT and TABT values at the root apex in the lingual-inclined group were significantly lower than in the other groups (p < 0.05). Lingual and labial ABT values were very low at the cervical level in the lingual-inclined and normal groups. There was a higher prevalence of alveolar fenestration in the lingual-inclined group. CONCLUSIONS: Lingual-inclined maxillary central incisors have less bone support at the level of the root apex and a greater frequency of alveolar bone defects than normal maxillary central incisors. The bone plate at the marginal level is also very thin.
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Adulto , Humanos , Placas Óseas , Tomografía Computarizada de Haz Cónico , Incisivo , Prevalencia , DienteRESUMEN
Objective: Evaluate the changes in alveolar bone as a result of maxillary and mandibular incisor retraction in patients with bimaxillary protrusion by means of using lateral cephalograms and computed tomography (CT) scans and to investigate any occurrence of bony defects like dehiscence and fenestration. Subjects and Methods: Ten patients (age 15 ± 3 years) with bimaxillary protrusion treated by extraction of four first premolars were investigated by lateral cephalograms and CT scans during pre‑treatment (T1) and after 3 months of completion of incisor retraction (T2). The labial and lingual cortex of all the incisors were assessed on the CT scan with measurements taken at site adjacent to widest point of the labiolingual root in three slices separated by 3 mm at crest level (S1), mid root level (S2), and apical level (S3). Result: In the mandibular arch, after lingual movement of the incisors, the bone labial to the anterior teeth decreased in thickness at the coronal level of the left lateral and left central incisors. Left lateral incisor showed significant changes in all the three levels. In the maxilla the change in the labial bone thickness was not statistically significant. Lingual bone of all the incisors showed significant changes in S1 level and S3 levels. Few patients demonstrated bone dehiscence that was not visible macroscopically or cephalometrically. Conclusions: When incisors are retracted, the risk of adverse effect is present. This must be carefully monitored to avoid negative iatrogenic effects. This study needs follow up after 6 months or 1 year after completion of the orthodontic treatment to assess the long‑term consequences.
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PURPOSE: The purpose of this study was to provide an actual guideline in determining the shape, diameter, and position of the implant in immediate implantation by the measurement of the thickness of facial and palatal plate, the thickness of cortical bone on the facial and palatal plate, the diameter of the root, and the distance between the roots in the cadavers. MATERIALS AND METHODS: The horizontal sections of 20 maxillae were measured and analyzed to obtain the average values. Resin blocks were produced and cut serially at 1 mm intervals from the cervical line to the root apex. Images of each section were obtained and the following measurements were performed: The thickness of the facial and palatal residual bone at each root surface, the thickness of the facial and palatal cortical bone at the interdental region, the diameter of all roots of each section on the faciopalatal and mesiodistal diameter, and the interroot distance. Three specimens with measurements close to the average values were chosen and 3-dimensional images were reconstructed. RESULTS: The thickness of the facial and palatal cortical bone at the interdental region in the maxilla, the buccal cortical bone was thicker in the posterior region compared to the anterior region. The interroot distance of the alveolar bone thickness between the roots increased from anterior to posterior region and from coronal to apical in the maxilla. CONCLUSION: In this study, the limited results of the morphometric analysis of the alveolar ridge using the sections of maxilla in the cadavers may offer the useful information when planning and selecting optimal implant for immediate implantation in the maxilla.
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Proceso Alveolar , Cadáver , MaxilarRESUMEN
The main aim of dental implant placement on the anterior region is to recover the function and esthetics. Therefore, this study examined the angulation between the long axis of the anterior teeth and the alveolar process, and thickness of the alveolar bone on the anterior region. Twenty-five cadaver heads (18 maxillae and 23 mandibles) were examined (16 male and 9 female, mean: 56.7 years). The angulation between the long axis of the anterior teeth and the alveolar process was measured, and the alveolar bone thickness was measured in the three levels (crest; C, middle; M, apex; A) on the labial and lingual sides. All data was analyzed statistically using one-way ANOVA. The maxillary anterior teeth showed two to three times more lingual inclination than the mandibular teeth. The difference in maxillary alveolar bone thickness on the labial and lingual sides was significant in all levels, particularly in the apex. The mandibular alveolar bone thickness on the labial and lingual side was significantly different only in the apex. In conclusion, the alveolar bone thickness on the anterior region was too thin, and the long axis of the maxillary anterior teeth showed more lingual inclination than the alveolar process. Therefore, clinicians need to be a detailed assessment of the labial alveolar bone for dental implant placement.
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Femenino , Humanos , Masculino , Proceso Alveolar , Vértebra Cervical Axis , Cadáver , Implantes Dentales , Estética , Cabeza , Maxilar , DienteRESUMEN
The main aim of dental implant placement on the anterior region is to recover the function and esthetics. Therefore, this study examined the angulation between the long axis of the anterior teeth and the alveolar process, and thickness of the alveolar bone on the anterior region. Twenty-five cadaver heads (18 maxillae and 23 mandibles) were examined (16 male and 9 female, mean: 56.7 years). The angulation between the long axis of the anterior teeth and the alveolar process was measured, and the alveolar bone thickness was measured in the three levels (crest; C, middle; M, apex; A) on the labial and lingual sides. All data was analyzed statistically using one-way ANOVA. The maxillary anterior teeth showed two to three times more lingual inclination than the mandibular teeth. The difference in maxillary alveolar bone thickness on the labial and lingual sides was significant in all levels, particularly in the apex. The mandibular alveolar bone thickness on the labial and lingual side was significantly different only in the apex. In conclusion, the alveolar bone thickness on the anterior region was too thin, and the long axis of the maxillary anterior teeth showed more lingual inclination than the alveolar process. Therefore, clinicians need to be a detailed assessment of the labial alveolar bone for dental implant placement.
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Femenino , Humanos , Masculino , Proceso Alveolar , Vértebra Cervical Axis , Cadáver , Implantes Dentales , Estética , Cabeza , Maxilar , DienteRESUMEN
OBJECTIVE: The purpose of this study was to determine the changes of mandibular anterior alveolar bone thickness with age. METHODS: Cephalometric radiographs of 160 skeletal class I patients (male 80, female 80) with normal vertical growth pattern was investigated by measuring the buccolingual thickness of mandibular alveolar bone on the basis of root axis. RESULTS: As the age increases, both male and female showed a significant decrease in buccolingual width of the mandibular anterior alveolar bone and in the width of mandibular anterior lingual alveolar bone except the CEJ area of females. However, there was no significant difference in the thickness of mandibular anterior buccal alveolar bone and in the width of maximum prominence of mandibular symphysis with age. CONCLUSION: From the above results, it is concluded that Korean children whose growth pattern is sagittally skeletal class I with a vertical normal growth pattern have a greater mandibular anterior lingual alveolar bone width than Korean adults; therefore, lingual movement of mandibular incisors, which is usually accompanied in extraction treatment, is considered to be more preferable in younger patients.