Recovery bone formation on radiographic palatal bone dehiscences after incisor retraction with microimplants.

OBJECTIVES: To investigate the difference in labial and palatal alveolar bone thickness and height during the retention period after incisor retraction treatment with microimplant. MATERIALS AND METHODS: A sample of 21 patients (mean age: 17.80 ± 4.38 years) who underwent incisor retraction treatment using microimplants after premolar extraction was investigated. The cone-beam computed tomography images at pretreatment, posttreatment, and retention were used to measure anterior alveolar bone thickness (labial, palatal, and total; at three vertical levels) and height (labial and palatal) and differences in the incisor position during treatment or retention. Repeated-measures analysis of variance with Bonferroni correction was performed to compare the variables at T0, T1, and T2. RESULTS: The maxillary central incisor moved posteriorly by approximately 8.0 mm along with intrusive movement of 1.8 mm after treatment. The alveolar bone thickness significantly decreased on the palatal side and increased on the labial side after treatment. Thereafter, the palatal bone thickness significantly increased and labial bone thickness decreased during the retention period. The palatal interdental bone depressed by incisor retraction showed substantial bone deposition after retention. CONCLUSIONS: Radiographic palatal bone dehiscences on the incisor root and palatal bone depression between the incisor roots were apparent after treatment. This palatal bone loss around the incisor roots noticeably recovered with newly formed bone during retention.

Multivariate analysis of alveolar bone dehiscence and fenestration in anterior teeth after orthodontic treatment: A retrospective study.

OBJECTIVE: To compare the prevalence of fenestration and dehiscence between pre- and post-orthodontic treatment and to explore the factors related to fenestration and dehiscence in the anterior teeth after treatment. METHODS: This study included 1000 cone-beam computed tomography (CBCT) scans of 500 patients before (T1) and after (T2) orthodontic treatment. These images were imported into Dolphin 11.9 software to detect alveolar fenestration and dehiscence in the anterior teeth area. The chi-square test and Fisher's exact test were performed to compare the prevalence of alveolar bone defects between time points T1 and T2. A total of 499 patients were selected for logistic regression analysis to examine the correlation among age, sex, crowding, sagittal facial type, extraction, miniscrew use and fenestration or dehiscence post-treatment. RESULTS: Except for the maxillary lingual fenestration and labial fenestration of mandibular canines, a significant change in the prevalence of fenestration and dehiscence was noted between time points T1 and T2 (P < .025). Multinomial logistic regression showed that age, miniscrew use and extraction highly influenced the prevalence of anterior lingual dehiscence (P < .05). Dehiscence of the mandibular labial side (skeletal Class III vs. I, OR = 2.368, P = .000) and fenestration of the mandibular lingual side (skeletal Class II vs. I, OR = 2.344, P = .044) were strongly correlated with the sagittal facial type. Dehiscence of the maxillary labial side (moderate vs. mild, OR = 1.468, P = .017) was significantly associated with crowding. CONCLUSIONS: Older age, maxillary moderate crowding, skeletal Class III, extraction and miniscrew potentially significantly affect the prevalence of anterior teeth dehiscence. Adult females, skeletal Class III patients on the mandibular labial side and skeletal Class II patients on the mandibular lingual side should be monitored for anterior teeth fenestration.

Randomized controlled pilot study comparing small buccal defects around dental implants treated with a subepithelial connective tissue graft or with guided bone regeneration.

AIM: To compare subepithelial connective tissue grafts (SCTG) versus guided bone regeneration (GBR) for the treatment of small peri-implant dehiscence defects in terms of profilometric (primary outcome), clinical, and patient-reported outcome measures (PROMs). METHODS: Sixteen patients who presented with small buccal bone dehiscences (≤3 mm) following single implant placement were recruited. Following implant placement, buccal bone defect sites were randomly treated either with a SCTG or GBR. Six patients who lacked bone dehiscences after implant placement were assigned to a negative control. Transmucosal healing was applied in all patients. Patients were examined prior (T1) and after (T2) implant placement, at suture removal (T3), at implant impression (T5), at crown delivery (T6), and 12 (T7) months after crown delivery. Measurements included profilometric outcomes, marginal bone levels, buccal bone and soft tissue thickness, PROMs, and clinical parameters. All data were analyzed descriptively. RESULTS: The median changes in buccal contour as assessed by profilometric measures between T1 and T5 showed a decrease of 1.84 mm for the SCTG group and 1.06 mm for the GBR group. Between T2 and T7, the median change in the buccal contour amounted to 0.45 mm for SCTG and -0.94 mm (=loss) for GBR. Patients' pain perception tended to be higher in SCTG than in GBR. All peri-implant soft tissue parameters showed healthy oral tissues and no clinically relevant differences between groups. CONCLUSION: Within the limitations of this pilot study, treating small peri-implant dehiscence defects with a SCTG might be a viable alternative to GBR. The use of a SCTG tended to result in more stable profilometric outcomes and comparable clinical outcomes to GBR. However, patient-reported outcome measures tended to favor GBR.

Bone Remodeling during Orthodontic Movement of Lower Incisors-Narrative Review.

The tooth movement in the alveolus is possible due to bone remodeling. This process could be the risk factor for the formation of gingival recessions-the most common side effects of orthodontic therapy. Gingival recessions are found 5.8-11.5% more frequently among the orthodontically treated patients. What is more, anterior mandibular teeth are the ones most prone to gingival recession dehiscences and fenestrations. The aim of this narrative review was to evaluate, based on CBCT (Cone beam computed tomography) scans, the changes in the alveolar bone of lower incisors in adolescent and adult patients after orthodontic tooth movements. From the pool of 108 publications, a total of 15 fulfilled the criteria of this review. Both retrospective and prospective longitudinal studies-using CBCT or CT (Computed Topography) and evaluating alveolar bone changes in mandibular incisors during orthodontic treatment performed before and after teeth movement-were included. In the group of growing patients, either proclination or retroclination of mandibular incisors led to increase of the distance from CEJ (cementoenamel junction) to marginal bone crest. The difference in bone loss was greater on the lingual side of the incisors in both types of tooth movement. The results were similar for adults patients. The thickness of the alveolar bone was reduced after proclination (total bone thickness) among growing and non-growing patients and retraction (lingual and buccal) of lower anterior teeth in the group of growing patients. The only improvement was measured for buccal thickness of mandibular incisor in bimaxillary protrusion patients treated with extraction therapy. The control of retraction movement (more root than crown movement) enhanced preservation on bone height and thickness. In order to minimize possible deterioration and place teeth in the center of alveolus, CBCT monitoring and scrupulous clinical evaluation are recommended.

Positive relationship between the dimensions of clinical gingival recessions and associated alveolar bone dehiscences: a biometric study.

OBJECTIVES: To analyze the relationships between the dimension of clinical gingival recession and of the actual bone dehiscence. METHOD AND MATERIALS: Data included measurements taken before and during root coverage surgical procedures. General health, smoking status, previous orthodontic treatment, probing depth, clinical measurements taken on gingival recessions, and the exposed alveolar bone dehiscences were recorded. Data were analyzed using descriptive statistics and linear regression model. RESULTS: Twenty-three patient files were available. The mean age was 31.3 ± 12.1 years (range 13 to 51 years). Eight patients had previous orthodontic treatment. Incisor, canine, and premolar recessions amounted to 9, 8, and 6 teeth, respectively. The deepest recession per patient was recorded. The mean alveolar bone dehiscence depth was 6.78 ± 1.2 mm (range 5 to 9 mm). Patient-related or systemic findings, preceding orthodontic treatment, and tooth type were not correlated with alveolar bone dehiscence dimensions. A significant association was found between clinical recession and the alveolar bone dehiscence depths (P < .001, Fisher exact test). On average, each 1 mm increase in clinical recession depth involved an increase of 1.45 mm in alveolar bone dehiscence depth (P < .001, linear regression). The ratio between the clinical recession depth and width was significantly associated with the depth of the bone dehiscence (P = .007, Fisher exact test). CONCLUSION: Within the limitations of the size of this study, clinical recession depth and width dimensions may help to predict the underling bone dehiscence magnitude. Gingival recession is associated with deformities of the underlying alveolar bone; this may be revealed during mucogingival procedures associated with full-thickness flaps. The association between the two may be of particular value to the operator as it may significantly affect the outcome of treatment. Furthermore, this relationship is of utmost importance in minimally invasive procedures that avoid flap elevation. A significant association was found between the depth of the clinical gingival recession and that of alveolar bone dehiscence. In addition, the ratio between the clinical recession depth and width was significantly associated with the depth of the bone dehiscence. Clinical recession depth and width dimensions may serve as an assessment predictor for the underling bone dehiscence magnitude.

Complication following frenectomy: A case report.

When performing a frenectomy in patients with an increased risk of exposing bone dehiscence, it is essential that the distance between the incisions is not too wide and that they are mainly made in the movable mucosa to secure optimal wound closure.

Immediate implant placement and loading in the esthetic area when the buccal socket wall is significantly damaged.

OBJECTIVES: Recent clinical recommendations contraindicate immediate implant placement when the socket buccal bone plate is significantly damaged. The connective tissue graft (CTG) is increasingly being used in implant therapy and can replace periodontal defects lacking bone wall in periodontal regenerative surgery. Therefore, CTG could be used to allow immediate implant placement and loading even when the buccal socket wall is damaged, facilitating graft material stability. CLINICAL CONSIDERATIONS: In the first case, deep bone dehiscence was caused by a vertical root fracture. In the second case, a big bone fenestration was caused by a chronic endodontic periapical lesion. Both cases were treated with immediate implant placement and loading. A buccal CTG was used to compensate for the lack of bone and allow stabilization of the particulate xenograft in the gap between the implant and the damaged buccal socket wall. In both cases, a provisional screw-retained crown was immediately delivered, and the definitive layered zirconia crown was delivered after 3 months. Esthetic results and patient satisfaction monitored for 1 year after loading proved to be encouraging. CONCLUSIONS: Although further investigations with longer follow-up are required, the approach is likely to yield good results after 1 year of loading. CLINICAL SIGNIFICANCE: The purpose of this report is to show a surgical approach that seems to be able to overcome the contraindication of the quoted consensus report, which allows for good esthetic results and patient satisfaction even when the buccal bone wall of the extraction socket has been more than 50% compromised, allowing treatment time and cost reduction.

Comparing membranes and bone substitutes in a one-stage procedure for horizontal bone augmentation. Three-year post-loading results of a double-blind randomised controlled trial.

PURPOSE: The objective of this 3-year post-loading parallel randomised controlled trial is to compare two bone substitutes and resorbable membranes in a one-stage procedure for horizontal bone augmentation: anorganic bovine bone and porcine collagen membranes (BB group) versus synthetic resorbable bone graft substitute made of pure ß-tricalcium phosphate and porcine pericardium collagen membranes (CJ group). MATERIALS AND METHODS: Patients in need of implant treatment having at least one site with horizontal osseous defect at a private clinic in Rimini, Italy, were included in this study. Patients were randomised to receive either BB or CJ in a one-stage procedure for horizontal bone augmentation in a submerged approach. Randomisation was computer-generated with allocation concealment by opaque sequentially numbered sealed envelopes. Patients and the outcome assessor were blinded to group assignment. The abutment connection was made after 6 months of healing. The application of the provisional prosthesis was performed after abutment connection and a definitive metal-ceramic prosthesis was placed 6 months post-loading. The patients were followed-up to 3 years post-loading. Primary outcome measures were: implant failure, complications and peri-implant margin bone level changes. Secondary outcome measures were: visual analogue scale (VAS) for functional and aesthetic satisfaction and pink aesthetic score (PES). RESULTS: Twenty-five patients with 32 implants were randomly allocated to the BB group and 25 patients with 29 implants to the CJ group. All 50 randomised patients received the treatment as allocated and there were 7 drop-outs in the BB group and 11 drop-outs in the CJ group up to 3 years' post-loading. There were no implant failures. There were six complications in five patients of the BB group and three complications in three patients of the CJ group (relative risk: 1.32, 95% CI from 0.37 to 4.64, P = 1.0000). Radiographic bone loss was 1.61 mm for the BB group and 1.02 mm for the CJ group (difference 0.54 mm, 95% CI from -0.53 to 1.60, P = 0.3100). The functional VAS was 9.0 for the BB group and 9.6 for the CJ group (difference 0.6, 95% CI from -0.4 to 1.5, P = 0.2393). The aesthetic VAS was 9.4 for the BB group and 9.6 for the CJ group (difference 0.2, 95% CI from -0.5 to 0.8, P = 0.6141). PES was 8.7 for the BB group and 8.5 for the CJ group (difference -0.1, 95% CI from -2.9 to 2.7, P = 0.9360). CONCLUSIONS: No significant differences were observed in this randomised controlled trial comparing anorganic bovine bone with porcine collagen membranes versus synthetic resorbable bone made of pure ß-tricalcium phosphate with pericardium collagen membranes for horizontal augmentation.

Effects of facial tooth movement on the periodontium in rats: a comparison between conventional and low force.

BACKGROUND: Bone dehiscences and gingival recession have been associated with orthodontic arch expansion. The aim of this study was to assess and compare periodontal modelling during application of two force levels. METHODS: The second and third upper molars were orthodontically moved buccally with conventional or low forces for 60 or 90 days in 32 rats. Ten non-treated animals were used as controls. The influence of force level and time on dental, skeletal and periodontal parameters (i.e. height and thickness of gingiva and bone) was assessed on histomicrographs using a mixed linear model. RESULTS: Facial tooth position (725 µm, CI 379-1072 µm, distal root of the third molar) and maxillary skeletal width (295 µm, CI 168-421 µm) differed significantly between force groups. Despite bone apposition at the facial aspects of the moved roots, bone dehiscences were developing and bone thickness was decreasing during facial tooth movement. Development of gingival recession was scarce and in cases with extreme facial tooth movement. No remarkable differences between force levels were found for any of the periodontal parameters. CONCLUSIONS: Facial tooth movement with conventional or low forces resulted in similar modelling of facial alveolar bone and gingiva.

A rat model for orthodontic translational expansive tooth movement.

OBJECTIVES: To present the development of an experimental model in rats for translational expansive tooth movement. SETTING AND SAMPLE: Section of Periodontology at Department of Dentistry Aarhus University. Twenty male Wistar rats in two pilot experimental settings plus seven animals without any intervention serving as controls. MATERIAL AND METHODS: The second molar (group P1) or the second and third molar (group P2) in the maxillae of the animals were moved buccally using transpalatal ß-titanium springs. In the group P2, two spring types (high force and low force) and two preangulations (0° passive or 30° torsion moment) were tested. The amount and type of tooth movement achieved and the resulting skeletal effect were assessed on microCT images, histological analysis was performed on few selected specimens. RESULTS: Expansive translational root movement amounting half a tooth width was achieved. Comparison of the amount of tooth movement at the right and left side of the maxilla showed that the expansion was rather symmetrical in the P2 group. Skeletal widening of the maxilla contributed in the P2 group to approximately one-third of the total root movement, whereas two-thirds were dental movement. CONCLUSION: With the model used in the P2 group, further research on translational expansive tooth movement and its effect on the periodontium can be pursued. In models for orthodontic expansion, it is strongly recommended to separately evaluate skeletal and dental effects.

A influência de imagens tridimensionais no plano de tratamento ortodôntico / Orthodontic treatment plan changed by 3-D images

INTRODUÇÃO: a tomografia computadorizada de feixe cônico (TCFC) foi introduzida no final da década de 90 e estudos têm aprimorado o seu emprego na Odontologia. OBJETIVO: o objetivo desse artigo foi verificar a influência de imagens tridimensionais (3D) no plano de tratamento ortodôntico. MÉTODOS: duas situações clínicas (reabsorção cervical e deiscência óssea) foram descritas por meio de imagens 3D. RESULTADOS: a conduta ortodôntica foi redirecionada para a simplificação da mecânica e o controle das lesões durante o tratamento ortodôntico. CONCLUSÃO: imagens 3D são capazes de aumentar a acurácia do diagnóstico e redirecionar o plano de tratamento ortodôntico.

INTRODUCTION: Cone-Beam Computed Tomography (CBCT) was introduced in the 90's and studies have improved its use in dentistry. OBJECTIVE: The aim of this article was to investigate the influence of three-dimensional (3D) images in orthodontic treatment planning. METHOD: Two clinical situations (bone dehiscence and cervical resorption) were described by 3D images. RESULTS: The orthodontic treatment plan was redirected to a simplified mechanics and control of the lesions during orthodontic treatment. CONCLUSION: 3D images are able to increase diagnostic accuracy and redirect orthodontic treatment plan.