Tissue changes resulting from facial tipping and extrusion of incisors in monkeys

Orthodontic tooth extrusion to regenerate missing papilla adjacent to maxillary anterior single implants: A 2- to 7-year retrospective study

INTRODUCTION

Regeneration of the missing papilla adjacent to single implants in the esthetic zone has always been challenging, despite advances in vertical hard and soft tissue regeneration. Orthodontic tooth extrusion has been shown to effectively gain alveolar bone and gingival tissue. This retrospective study evaluated the effectiveness of orthodontic tooth extrusion on regenerating missing papilla between existing maxillary anterior single implant and its adjacent tooth.

METHODS

Patients who underwent orthodontic tooth extrusion to regenerate missing papilla adjacent to a single implant in the esthetic zone were included in this study. The gingival phenotype, orthodontic extrusion movement, proximal bone level, dento-implant papilla level, facial gingival level, mucogingival junction level, and keratinized tissue width, of the extruded tooth were recorded at pre-orthodontic extrusion (T0 ), post-orthodontic extrusion and retention (T1 ), and latest follow-up (T2 ).

RESULTS

A total of 17 maxillary single tooth had orthodontic tooth extrusion to regenerate missing papilla adjacent to 14 maxillary anterior single implants in 14 patients. After a mean follow-up time of 48.4 months, implant success rate was 100% (14/14), with none of the orthodontically extruded teeth being extracted. After a mean extrusion and retention period of 14.3 months, a mean orthodontic extrusion movement of 4.62 ± 0.78 mm was noted with a mean proximal bone level gain of 3.54 ± 0.61 mm (77.0% efficacy), dento-implant papilla level gain of 3.98 ± 0.81 mm (86.8% efficacy), and facial gingival tissue gain of 4.27 mm ± 0.55 mm (93.4% efficacy). A mean keratinized tissue width gain of 4.17 ± 0.49 mm with minimal mean mucogingival junction level change of 0.10 ± 0.30 mm were observed. The efficacy of orthodontic eruption movement on dento-implant papilla gain was less in the thin (80.5%) phenotype group when compared with that in the thick (91.5%) phenotype group.

CONCLUSIONS

Within the confines of this study, orthodontic extrusion is an effective, noninvasive method in regenerating mid-term stable proximal bone and papilla adjacent to maxillary anterior single implants.

CLINICAL SIGNIFICANCE

This retrospective study presents a mid-term result on orthodontic extrusion as a mean to regenerate dento-implant papilla defect. The extended retention period following orthodontic extrusion showed stable and efficacious proximal bone and papilla gain.

Periodontal Phenotype Modification Using Subepithelial Connective Tissue Graft and Bone Graft in the Mandibular Anterior Teeth with Mucogingival Problems Following Orthodontic Treatment

Among the complications of orthodontic treatment, mucogingival problems with gingival recession in the mandibular anterior teeth are challenging for clinicians. Mucogingival problems can lead to esthetic deficits, thermal hypersensitivity, tooth brushing pain, and complicated plaque control. Herein, we present a case of a 16-year-old female with gingival recession in the left mandibular central incisor after orthodontic treatment. The preoperative clinical findings showed a thin soft tissue biotype with root prominence in the mandibular anterior area. The interdental area was relatively depressed. After reflection of the full-thickness flap, root coverage using a bone graft substitute and subepithelial connective tissue graft obtained from the palatal mucosa was performed. The 6-month and 5-year postoperative clinical findings showed improved soft tissue phenotype. The cross-sectional CBCT scans 5 years after surgery showed a well-maintained labial bone plate in the mandibular incisors. Within the limitations of this case report, for patients with gingival recession in the mandibular incisors after orthodontic treatment, a successful biotype modification can be achieved with a combined procedure using subepithelial connective tissue graft with bone graft substitutes.

Impact of orthodontic correction of dental crowding with pre-molar extraction in the anterior mandible evaluated by cone-beam computed tomography

INTRODUCTION:

To evaluate, by cone-beam computed tomography (CBCT), the change in thickness and height of the alveolar bone and interdental septum in the anterior mandible after orthodontic treatment for dental crowding using tooth extraction.

MATERIAL AND METHODS:

The sample consisted of 48 mandibular incisors from adult patients who presented with Class I malocclusion and required orthodontic treatment with the extraction of mandibular premolars. CBCT images were taken before starting the treatment (T1) and three months after treatment (T2). The following measurements were evaluated: width and height of the alveolar bone and the interdental septum, the distance between the cementoenamel junction and the bone ridges (F-CEJ-MBC and L-CEJ-MBC), as well as the vertical positioning and inclination of the incisor, using the Lingual Plane as the reference point. The paired Student's t-test and Pearson correlation were used with a significance level of 5%.

RESULTS:

A significant increase was observed in the distance L-CEJ-MBC, which shows the appearance of bone dehiscence. The degree of dental crowding was not a risk factor for the development of dehiscence. The decrease in the incisor inclination and intrusion was related to the formation of dehiscence on the lingual surface.

CONCLUSION:

The variation in the incisor's inclination and intrusion during the treatment of dental crowding using tooth extraction are related to the formation of bone dehiscence on its lingual surface.

Canine root/cortical bone relation (CRCR) and the orthodontic tooth movement

This observational study evaluates three-dimensionally the relation between the root of maxillary canine and overlying labial cortical plate of bone during orthodontic canine retraction. Eighty-four bilateral maxillary canines in 42 patients were retracted in the extraction space of first premolars, using conventional orthodontic NiTi retraction spring delivering 150gm. Three-dimensional evaluation at the cusp tip, root apex, and the overlying cortical bone was done based on Classification of Root/Cortical bone relation (CRCR) before and after canine retraction. 168 observations of the canines pre- and post-retraction showed a mean distal movement of the canine cusp tip of 3.78(± 2.05) mm, while the canine root apex was almost stationary. Scarcely, 5.4% of the canine roots and root apices persisted in the medullary bone during retraction, while 16.1% contacted the overlying cortical bone. Fenestration of the overlying cortical bone by the canine roots or root apices occurred in 78.6% of the sample. The unembellished intimacy between the canine root and apex to the overlying thick dense cortical bone might have the decelerating effect on the maxillary canine retraction. The natural bone plate labial to the maxillary canine root did not yield infront nor enlarge due to canine retraction, but else defeated the current orthodontic biomechanical implementation.

Clinical Considerations in Orthodontically Forced Eruption for Restorative Purposes

For restorations on teeth involving invasion of the supracrestal tissue attachment (biological width), as well as for lack of ferrule effect, crown lengthening is required for long-term periodontal health and success of the restoration. In the same fashion, site development is often necessary prior to implant placement in order to provide optimal peri-implant soft and hard tissue architecture conducive to future esthetics and function. Orthodontic extrusion, also known as forced eruption, has been developed and employed clinically to serve the purposes of increasing the clinical crown length, correcting the periodontal defect, and developing the implant site. In order to provide comprehensive guidance on the clinical usage of this technique and maximize the outcome for patients who receive the dental restoration, the currently available literatures were summarized and discussed in the current review. Compared to traditional crown lengthening surgery, forced eruption holds advantages of preserving supporting bone, providing improved esthetics, limiting the involvement of adjacent teeth, and decreasing the negative impact on crown-to-root ratio compared to the traditional resective approach. As a non-invasive and natural technique capable of increasing the available volume of bone and soft tissue, forced eruption is also an attractive and promising option for implant site development. Both fixed and removable appliances can be used to achieve the desired extrusion, but patient compliance is a primary limiting factor for the utilization of removable appliances. In summary, forced eruption is a valuable treatment adjunct for patients requiring crown lengthening or implant restorations. Nonetheless, comprehensive evaluation and treatment planning are required for appropriate case selection based upon the known indications and contraindications for each purpose; major contraindications include inflammation, ankylosis, hypercementosis, vertical root fracture, and root proximity. Further studies are necessary to elucidate the long-term stability of orthodontically extruded teeth and the supporting bone and soft tissue that followed them.

Periodontal and Periapical Outcomes of Surgical Extrusion: A Prospective Clinical Volumetric Study

INTRODUCTION

Outcome predictors for the restoration of endodontically treated teeth mainly include cavity wall integrity and the presence of a 1.5-2 mm ferrule. However, in some clinical situations, the aforementioned predictors cannot be achieved. Three different techniques have been proposed to obtain an adequate ferrule respecting the supracrestal tissue attachment: surgical crown lengthening, orthodontic forced eruption, and surgical extrusion. There are little published prospective data evaluating periodontal changes after surgical extrusion. Therefore, the aims of this study were to report the outcome of surgical extrusion in single-rooted teeth, to digitally evaluate soft tissue volumetric changes after surgical extrusion, and to observe patient satisfaction regarding the treatment after a minimum of 1 year.

METHODS

This prospective clinical study was performed between 2017 and 2020. Thirteen patients referred for surgical extrusion met the following inclusion criteria: nonsmokers; systemically healthy with at least 1 straight, single-rooted tooth with an insufficient ferrule; a favorable tooth crown-to-root ratio, and no periodontal pathology. Preoperative clinical variables included patient age, sex and phenotype, tooth number, tooth mobility, crown-to-root ratio, gingival index (GI), probing pocket depths at 6 sites, bleeding on probing (BOP), and mesial and distal interproximal papillae volume. Surgical extrusion was performed by a single operator who completed the root canal treatment/retreatment and restored the teeth with a crown. One year later, all patients were controlled, and the following variables were recorded: tooth mobility, crown-to-root ratio, GI, pocket depth, BOP, interproximal papillae aspect, soft tissue rebound, periapical healing, marginal bone loss, and patient-reported outcome measures of the treatment. All variables were analyzed using a descriptive method (mean, %). The Wilcoxon test was used to evaluate pre- and postoperative clinical parameters at a significance level of .05.

RESULTS

At a mean follow-up period of 18.8 months, no teeth were extracted. Compared with preoperative GI and BOP, a significant reduction was observed at 1 year after surgery. Likewise, no significant differences in probing depths were shown, and only 1 tooth presented a type 2 mobility. The mean soft tissue rebound was -0.46 ± 0.69 mm. Overall, no significant interproximal papillae height loss was observed.Apical lesions were completely healed after surgery. The tooth crown-to-root ratio was favorable in all cases before extrusion, whereas in 3 cases it was appropriate (1 = 1), and only 1 case presented >25% of marginal bone loss during the follow-up period. The reported success rate was 92.3%, and patients were generally satisfied with the outcome.

CONCLUSIONS

Surgical extrusion of single-rooted teeth was successful with minimal or no soft tissue loss, and patients were satisfied with the surgical procedure and the esthetic result.

Herbst-multibracket appliance treatment: is there an association between lower incisor position changes and the development of labial gingival recessions?

PURPOSE

To assess a potential association between lower incisor (LI) position changes during Herbst-multibracket appliance (Herbst-MBA) treatment and the development of labial gingival recessions (LGR).

METHODS

All class II patients (Department of Orthodontics, University of Giessen, Giessen, Germany) who had undergone Herbst-MBA treatment until 2015 with study models and lateral cephalograms available from before (T0) and after treatment plus ≥24 months of retention (T3) were included (n = 259). Lateral cephalograms were evaluated regarding LI position changes: iiL/ML (angle between LI long axis and mandibular plane [MP]), ii-MLPg (distance between LI incisal edge and a line perpendicular to MP through pogonion), apex-MLPg (distance between LI apex and a line perpendicular to MP through pogonion), ii-MLii (distance between LI incisal edge and MP on a line perpendicular to MP through incisal edge). Using study models the distance between the cementoenamel junction and the deepest point of the gingival margin was defined as LGR.

RESULTS

The following cephalometric mean changes were recorded (T0-T3): iiL/ML +5.9 ± 5.76° (p = 0.929), ii-MLPg -0.2 ± 0.25 mm (p = 0.430), apex-MLPg +0.1 ± 0.32 mm (p = 0.363), ii-MLii +0.1 ± 0.36 mm (p = 0.206). The mean increase of LGR magnitude measured on the study models was 0.1 ± 0.35 mm. However, no association with the cephalometric LI position changes was found (|R| ≤ 0.2).

CONCLUSION

There is no association between the amount of LI position changes and the development of LGR during Herbst-MBA treatment plus retention. Nevertheless, individual predisposition or excessive treatment changes and extraordinary treatment approaches, respectively, might still lead to development of LGR.

Bone changes in the mandibular incisors after orthodontic correction of dental crowding without extraction: A cone-beam computed tomographic evaluation

Purpose

This study aimed to evaluate changes of the alveolar bone and interdental bone septum of the mandibular incisors through cone-beam computed tomography (CBCT) after orthodontic treatment of mandibular dental crowding without dental extraction.

Materials and Methods

The sample consisted of 64 CBCT images (32 pre-treatment and 32 post-treatment) from 32 adult patients with class I malocclusion and an average age of 23.0±3.9 years. The width and height of the alveolar bone and interdental septum, the distance between the cementoenamel junction (CEJ) and the facial and lingual bone crests, and the inclination of the mandibular incisors were measured.

Results

The distance between the CEJ and the marginal bone crest on the facial side increased significantly (P<0.05). An increased distance between the CEJ and the bone crest on the facial and lingual sides showed a correlation with the irregularity index (P<0.05); however, no significant association was observed with increasing mandibular incisor inclination (P>0.05). The change in the distance between the CEJ and the marginal bone crest on the facial side was correlated significantly with bone septum height (P<0.05).

Conclusion

Bone dehiscence developed during the treatment of crowding without extraction only on the incisors' facial side. Increasing proclination of the mandibular incisor was not correlated with bone dehiscence. The degree of dental crowding assessed through the irregularity index was associated with the risk of developing bone dehiscence. The interdental septum reflected facial marginal bone loss in the mandibular incisors.

Impact of Orthodontic Forces on Plasma Levels of Markers of Bone Turnover and Inflammation in a Rat Model of Buccal Expansion

Plasma levels of protein analytes might be markers to predict and monitor the kinetics of bone and tissue remodeling, including maximization of orthodontic treatment stability. They could help predict/prevent and/or diagnose possible adverse effects such as bone dehiscences, gingival recession, or root resorption. The objective of this study was to measure plasma levels of markers of bone turnover and inflammation during orthodontic force application in a rat model of orthodontic expansion. Two different orthodontic forces for bilateral buccal expansion of the maxillary arches around second and third molars were applied in 10 rats equally distributed in low-force (LF) or conventional force (CF) groups. Four rats served as the control group. Blood samples were collected at days 0, 1, 2, 3, 6, 13, 21, and 58. Longitudinal concentrations of osteoprotegerin (OPG), soluble receptor activator of nuclear factor kappaB ligand (sRANKL), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNF), and parathyroid hormone (PTH) were determined in blood samples by a multiplex immunoassay. CF and LF resulted in a significantly maxillary skeletal expansion while the CF group demonstrated significantly higher expansion than the LF group in the long term. Bone turnover demonstrated a two-phase response. During the “early phase” (up to 6 days of force application), LF resulted in more sRANKL expression and increased sRANKL/OPG ratio than the CF and control animals. There was a parallel increase in PTH levels in the early phase in response to LF. During the “late phase” (6–58 days), the markers of bone turnover were stable in both groups. IL-4, IL-6, and IL-10 levels did not significantly change the test groups throughout the study. These results suggest that maxillary expansion in response to different orthodontic forces follows different phases of bone turnover that may be force specific.

Histomorphometric Comparison between Two Types of Acellular Dermal Matrix Grafts: A Mini Pig Animal Model Study

Acellular dermal matrix grafts (ADMG) have been used as soft tissue graft substitutes for autografts in periodontal plastic surgical procedures. They have benefits like avoiding a second surgical site and patient morbidity that have been associated with autografts, but there is limited evidence available on their tissue response and wound healing process. This histomorphometric animal model study was carried out in mini pigs and it aimed to compare the two types of ADMG materials of porcine derivative with a control group through observation of parameters like epithelial and Keratinized layer thickness, angiogenesis, cellularity, matrix resorption, and inflammatory infiltrate. The surgical technique involved punctures on the edentulous areas stripping the epithelial tissue and exposing the underlying connective tissue, placement of the ADMGs in the appropriate control and test sites. Following this, gingival biopsies were procured at three different time intervals of 15, 45, and 90 days. There were significant differences in epithelial and Keratinized layer thickness among the three groups. This study concluded that there was no clear consensus on which graft material was superior but it gave an insight into the tissue response and wound healing process associated with the graft materials.

Postorthodontic lower incisor and canine inclination and labial gingival recession in adult patients : A prospective study

PURPOSE

The goal was to determine whether changes in the inclination of lower incisors and canines upon orthodontic treatment with fixed appliances poses a threat for labial gingival recession in adult patients.

METHODS

The sample of this prospective clinical trial consisted of 32 adult patients (mean age 25.08 ±6.50 years) treated with fixed appliances. Plaque and bleeding indices, probing pocket depth, clinical attachment level, gingival recession height (GR) and width (GRW), gingival thickness (GT), and keratinized tissue width were clinically recorded, while cone beam computed tomography (CBCT) was used to evaluate teeth inclination before (T1) and after treatment (T2). Oral hygiene, brushing habits, and smoking were controlled.

RESULTS

During orthodontic treatment on 15 (8.33%) teeth (10 incisors and 5 canines), spontaneous complete improvement of pre-existing GR was observed. On 2 incisors, GR decreased and on 3 teeth GR did not change. Moreover, 1 incisor presented an increased GR, while 2 teeth developed new defects. Mean GR, GRW, and GT decreased significantly only on the incisors. Proclination of incisors and canines during treatment (compared with retroclination of the teeth) implicated a lower reduction in GR at T2: 0.19 mm (p = 0.034) and 0.18 mm (p = 0.037), respectively. Multiple regression analysis confirmed that more tooth proclination was associated with a higher risk for an increase in GR (p < 0.00).

CONCLUSION

Properly planned changes in lower incisor and canine inclination can be carried out in adult patients without posing a high risk to labial gingival recessions if the individual periodontal biotype is respected. The reported outcomes underscore the orthodontic principle to keep tooth roots inside the alveolar bone.

Improvement of Periodontal Parameters with the Sole Use of Free Gingival Grafts in Orthodontic Patients: Correlation with Periodontal Indices. A 15-Month Clinical Study

The aim of this study was to evaluate the changes in periodontal parameters solely using free gingival grafts during orthodontic treatment without any oral hygiene re-enforcement. Methods: A total of 19 patients underwent periodontal examination before orthodontic treatment. Patients received oral hygiene instruction and professional hygiene therapy. Where needed; full periodontal treatment was completed. Only periodontally stable patients were included in the study. Periodontal indices and keratinized tissue were recorded at time 0 (T0) (delivery of orthodontic appliances), and at three months (T1) during orthodontic therapy; when surgery was performed. At T1; orthodontically treated sites with minimum keratinized tissue (≤1 mm) received a free gingival graft to enhance the band of keratinized tissue. At three months after surgery (T2), new measurements were recorded. The orthodontics-treated sites after three months (T1) were used as control. The same sites were used as a test three months after mucogingival correction (T2). Between T1 and T2; orthodontics was suspended; no professional oral hygiene was performed; and no additional oral hygiene instructions were given to the patient. No oral hygiene procedures were administered for 15 months (T3), when the final recordings were taken. Results: The results showed that there was a worsening of gingival index (GI) and plaque index (PI) of the treated sites between T0 and T1 during initial orthodontics treatment; whereas there was an improvement of the gingival inflammation at T2 when compared with T1. At T2; there was also a statistically significant improvement in GI and PI compared with T0. A T3 improvement in periodontal parameters was sustained. A non-parametric test (Wilcoxon signed-rank test) was used for statistical analysis. Conclusions: Augmentation of the width of keratinized gingiva; as the sole treatment; favors the improvement of GI and PI during orthodontic therapy.

Biologically oriented preparation technique for surgically extruded teeth: A clinical report

Surgical extrusion allows a ferrule to be obtained without the use of orthodontic extrusion or the need to remove hard and soft tissues. However, after the healing period, the soft tissue of the extruded tooth might become thinner, creating an unesthetic gingival margin. Unlike other preparation techniques, the biologically oriented preparation technique provides increased long-term gingival thickness. This article describes the treatment of 3 patients with teeth with no ferrule that were surgically extruded and restored with the biologically oriented preparation technique .

The heritability of alveolar bone thickness in siblings seeking orthodontic treatment

INTRODUCTION

The purpose of this study was to calculate heritability estimates of alveolar bone thickness around maxillary and mandibular incisors.

METHODS

The sample consisted of cone-beam computed tomography scans of 69 groups of siblings. The scans were analyzed, and Invivo5 software was used to measure the labial and lingual bone thickness. The central point of the root was identified as the point of rotation in order to construct the point of intersection with the outer bone surface. The linear distance was measured from this constructed point to the root apex. The general linear method was then used to calculate the heritability of alveolar bone thickness.

RESULTS

Heritability of alveolar bone thickness was, on average, 58.0% for maxillary incisors and 50.3% for mandibular incisors. These estimates indicate a moderate to high heritability of alveolar bone thickness with an overall average heritability of 54.1%.

CONCLUSIONS

Genetic factors were found to play significant roles in determining bone thickness around these teeth. The genetic effect on alveolar bone thickness around incisors is moderate to high.

Effects of orthodontic tooth extrusion produced by different techniques, on the periodontal tissues: a histological study in dogs

OBJECTIVE

The aim of this study was to compare the periodontal tissue changes resulting from different methods of orthodontic tooth extrusion in dogs.

MATERIALS AND METHODS

Notches were surgically prepared in the root surface at the bone crest level of the first premolars of mongrel dogs. After 37 days, extrusion of the first lower and upper premolars was randomly performed by 3 different methods: conventional orthodontic extrusion (OE); open flap debridement performed immediately before orthodontic extrusion (OF); and orthodontic extrusion associated with weekly fiberotomy and scaling (FS). For all groups, extrusion was performed for 21 days followed by one-month retention and sacrifice. Periodontal parameters, descriptive histology, and histomorphometric analyses were performed at the end of the experimental period.

RESULTS

The median extrusion was 2.25 in the fiberotomy group, 2.0 mm in the open flap group and 1.0 mm in the orthodontic extrusion group with no significant differences between groups. The highest distance between reference notch and bone crest was observed in the fiberotomy group (p < 0.05). Histologically, radicular resorption repaired with cellular cementum was detected in all groups.

CONCLUSIONS

Tooth extrusion was successfully achieved with all of the different methods of orthodontic tooth extrusion with no statistical significance between techniques. The fiberotomy approach was effective in avoiding coronal displacement of periodontal tissues. Fiberotomy associated with scaling should be indicated if the objective of the treatment is extrusion without periodontal tissue displacement.

Class II:2 malocclusion-prevalence and progression of labial gingival recessions during Herbst-Multibracket appliance treatment

OBJECTIVES

To determine the prevalence, incidence, and changes in magnitude of labial gingival recessions (LGR) in class II:2 patients during Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention.

SUBJECTS AND METHODS

All class II:2 patients of the Department of Orthodontics, University of Giessen, Germany who completed Herbst-MBA Tx (mean pre-Tx age 15.6 years). The cohort had undergone a Herbst phase (mean 8.1 months) as well as a subsequent MBA phase (mean 14.4 months). Study casts were evaluated from pre-Tx and after Herbst-MBA Tx plus ≥ 24 months of retention.

RESULTS

Ratable pre-Tx and post-retention study casts (total observation period 53.5 ± 10.3 months) were available from 94 out of 173 patients. No significant difference existed regarding pre-Tx LGR data between patients with and without complete records. The prevalence for teeth with LGR ≥ 0.5 mm was 1.4% pre-Tx respectively 6.7% post-retention. The highest values of up to 5.3% (pre-Tx) and 20.2% (post-retention) were determined for the upper first premolars and lower central incisors. Incidence values of 4.7% (all teeth) and up to 14.9% (upper first right premolars) respectively 11.1% (lower central incisors) were calculated (LGR ≥ 0.5 mm). The overall LGR mean magnitudes were 0.01 mm pre-Tx respectively 0.06 mm post-retention.

CONCLUSIONS

For the prevalence of LGR ≥ 0.5 mm an average increase of 5.3% was determined during ≈ 4.5 years of Herbst-MBA Tx plus retention. The highest incidence was seen for lower central incisors and upper right premolars (11.1/14.9%). The overall LGR mean magnitude increased by 0.05 mm.

CLINICAL RELEVANCE

Herbst-MBA Tx is a common approach for class II:2 malocclusions. Very little, however, is known regarding LGR development in respective patients.

Do orthodontic patients develop more gingival recession in anterior teeth compared to untreated individuals? A systematic review of controlled studies

OBJECTIVE

To investigate, in an evidence-based manner, the contemporary available information regarding the development of gingival recession in the anterior teeth of orthodontically treated and age-matched untreated individuals.

MATERIAL AND METHODS

Eight databases were searched without restrictions from the date of coverage initiation to June 30th, 2019 (registration in PROSPERO: CRD42018080948). Studies evaluating gingival recession development following comprehensive orthodontic treatment were reviewed. Following study selection, data extraction and risk of bias assessment, the random effects model was employed for exploratory data synthesis. The confidence in the retrieved estimates was appraised using current guidelines.

RESULTS

Finally, three studies, with a follow-up of 6 years maximum, were identified. Overall, the amount of gingival recession did not increase significantly immediately after treatment with normal occlusion. However, for some of the comparisons considered, the risk for orthodontic patients to present with labial gingival recession seemed to increase, especially during retention [mandibular incisors 6 years post-treatment: Odds Ratio: 8.81, 95% Confidence Interval: 1.93-40.07, p=0.005].

CONCLUSION

Although the amount of recession does not differ, some increase in the risk for gingival recession development in the anterior teeth may be encountered in orthodontically-treated individuals compared to untreated subjects with normal occlusion. However, these findings should be viewed cautiously until more studies of high quality become available. Good practice would suggest that it is important to identify patients at potential risk and consider the possible implications for orthodontic treatment.

Nonsurgical maxillary expansion in adults: report on clinical cases using the Hyrax expander

BACKGROUND

Maxillary expansion in adults is object of intense controversy and is still considered an unreliable procedure within the orthodontic community. Therefore, the surgically assisted rapid maxillary expansion is still considered the elective treatment nowadays. The aim of this study is to evaluate the efficacy of a nonsurgical maxillary expansion treatment in adult patients with unilateral or bilateral crossbites and to assess the occurrence of related complications, such as pain and tissue swelling, tipping of the posterior teeth and gingival recessions.

METHODS

Maxillary expansion using a Hyrax appliance on the upper first premolars and first molars was performed in 29 patients ranged between 18 and 32 years, mean age of 22±4 years. The sample included 13 patients with unilateral crossbite and 16 with bilateral crossbite. The statistical analysis was carried out using the SPSS Statistics version 23.0. An analysis of the paired data obtained on dental casts before and after treatment was performed using the Student's t-test.

RESULTS

The posterior crossbite was fully corrected in all patients. The procedure was well tolerated, and pain, swelling or discomfort was not significant. Statistically significant differences were found between the interdental widths for all pairs, with a P<0.001 for all of them, except in the measurements of canines, in which P=0.001. Measurements of clinical crown height at the beginning (T0) and at the end (T1) of treatment were performed for the same teeth. An increase of the clinical crown height between 0.14 and 0.44 mm was found for premolars and molars.

CONCLUSIONS

The results indicate that nonsurgical maxillary expansion in adult patients is an efficient method for correcting transverse deficiency in the maxillary arch. Similarly, the level of complications during treatment was not clinically significant, thus this procedure may be considered a safe treatment.

Prevalence, magnitude, and incidence of labial gingival recession with Herbst-multibracket appliance treatment: A retrospective cohort study

OBJECTIVE

To assess the prevalence and magnitude of labial gingival recession (LGR) before and after as well as the incidence during Class II:1 Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention in a retrospective cohort study.

MATERIALS AND METHODS

Records of Class II:1 patients who completed Herbst-MBA Tx (mean pre-Tx age 14.4 years) at Department of Orthodontics, University of Giessen, Giessen, Germany were analyzed. Tx consisted of a Herbst phase (mean 8.1 months) and a subsequent MBA phase (mean 16.1 months). Study casts from before and after Herbst-MBA Tx plus ≥24 months of retention were evaluated.

RESULTS

A total of 460 pre-Tx and 222 postretention study casts were available (total observation period: 59.2 ± 14.8 months). The overall prevalence for teeth with LGR ≥0.5 mm was 1.1% pre-Tx and 5.3% postretention. The highest prevalence of up to 5.3% (pre-Tx) and 16.4% (postretention) were seen for the lower incisors. Overall, the median magnitude of LGR was 0.0 mm pre-Tx/postretention (mean: 0.05 mm/0.08 mm). Incidence values of 4.0% (all teeth) and 10.0% to 11.4% (lower central incisors) were calculated for LGR ≥0.5 mm.

CONCLUSIONS

The prevalence of LGR ≥0.5 mm increased from, on average, 1.1% to 5.3% during ≈6 years of Herbst-MBA Tx plus retention. The highest incidence was seen in lower incisors (10.0%-11.4%). However, because of the overall mean magnitude of 0.08 mm postretention, the clinical relevance can be considered as insignificant.

Evaluation of changes in the maxillary alveolar bone after incisor intrusion

Objective

This study was performed to investigate the changes in alveolar bone after maxillary incisor intrusion and to determine the related factors in deep-bite patients.

Methods

Fifty maxillary central incisors of 25 patients were evaluated retrospectively. The maxillary incisors in Group I (12 patients; mean age, 16.51 ± 1.32 years) were intruded with a base-arch, while those in Group II (13 patients; mean age, 17.47 ± 2.71 years) were intruded with miniscrews. Changes in the alveolar envelope were assessed using pre-intrusion and post-intrusion cone-beam computed tomography images. Labial, palatal, and total bone thicknesses were evaluated at the crestal (3 mm), midroot (6 mm), and apical (9 mm) levels. Buccal and palatal alveolar crestal height, buccal bone height, and the prevalence of dehiscence were evaluated. Two-way repeated measure ANOVA was used to determine the significance of the changes. Pearson's correlation coefficient analysis was performed to assess the relationship between dental and alveolar bone measurement changes.

Results

Upper incisor inclination and intrusion changes were significantly greater in Group II than in Group I. With treatment, the alveolar bone thickness at the labial bone thickness (LBT, 3 and 6 mm) decreased significantly in Group II (p < 0.001) as compared to Group I. The LBT change at 3 mm was strongly and positively correlated with the amount of upper incisor intrusion (r = 0.539; p = 0.005).

Conclusions

Change in the labial inclination and the amount of intrusion should be considered during upper incisor intrusion, as these factors increase the risk of alveolar bone loss.

Post-orthodontic position of lower incisors and gingival recession: A retrospective study

Background

To evaluate if changes in lower incisor position following orthodontic treatment are correlated with development of gingival recessions.

Material and Methods

Pre- and post-treatment digital models and lateral cephalograms of 22 subjects were collected retrospectively. The clinical crown length, gingival scallop, and papilla height of the central lower incisor were measured along with the cephalometric incisor’s inclination, the distance from the mandibular plane, and the distance between the Infradentale and Menton points. Statistical correlations between gingival and cephalometric variables were studied. In addition, two groups were defined based on the post-treatment incisor inclination value (‘normal’ or ‘proclined’) and compared.

Results

The incisor inclination was correlated with the change in gingival scallop and papilla height. Moreover, there was a statistically significant difference in clinical crown height and gingival scallop between the ‘normal’ group and the ‘proclined’ group.

Conclusions

Changes in lower incisor position, especially an excessive proclination, after orthodontic treatment may play a role in the development of gingival recession.

Key words:Orthodontic treatment, Incisor inclination, IMPA, Gingival recession, Alveolar bone.

Long-term changes of the anterior palatal alveolar bone after treatment with bialveolar protrusion, evaluated with computed tomography

This case report describes the treatment of a 31-year-old woman with a convex profile, protrusive maxilla, retrusive mandible, and gummy smile. Four premolars were extracted, and micro-implant anchorage was used to retract the anterior teeth. Lip protrusion and the gummy smile were improved, but the computed tomography images showed dehiscence on the palatal alveolar bone of the maxillary incisors. Approximately 10 years after treatment, significant alveolar bone apposition was seen on the palatal surface of the maxillary anterior teeth.

Alveolar bone response to light-force tipping and bodily movement in maxillary incisor advancement: A prospective randomized clinical trial

OBJECTIVE

To compare alveolar bone thickness and height changes between untreated incisors (control), incisors advanced with light-force tipping, and incisors advanced with bodily movement mechanics.

MATERIALS AND METHODS

Forty-three subjects (aged 9.49 ± 1.56 years) with anterior crossbite were allocated into an untreated group (control), tipping group, or bodily movement group. Lateral cephalograms were taken before advancement (T₀) and after obtaining normal overjet (T₁). Changes in labial and palatal alveolar bone thickness and height surrounding maxillary incisors were evaluated with limited field-of-view cone-beam computed tomography before advancement (CT₀) and 4 months after normal overjet was obtained (CT₁). Wilcoxon matched-pairs signed-rank and Kruskal-Wallis one-way ANOVA tests were used to compare changes within and between groups, as appropriate. The significance level was set at .05.

RESULTS

Labial alveolar bone thickness at the midroot and apical levels were significantly decreased in the bodily movement group ( P < .05). However, between groups, there was no statistically significant difference in labial bone thickness changes at any level. Palatal and total alveolar bone thickness at the midroot and apical levels were significantly decreased in the tipping group compared with the control and bodily movement groups ( P < .05). Neither labial nor palatal bone height changes were significantly different among groups.

CONCLUSIONS

Maxillary incisor advancement with light-force tipping and bodily movement in growing patients resulted in labial alveolar bone thickness and labial and palatal alveolar bone height changes that were similar to the untreated group.

Gingival recessions of lower incisors after proclination by orthodontics alone or in combination with anterior mandibular alveolar process distraction osteogenesis

OBJECTIVES

The aim of this study was to longitudinally compare periodontal conditions in consecutive patients who had orthodontic treatment with proclination of lower incisors either by orthodontics alone or in combination with anterior mandibular alveolar process distraction osteogenesis (DO).

MATERIALS AND METHODS

Nineteen patients had orthodontic treatment with DO, 18 with extraction of lower premolars (Ex), and 18 without extractions (Nonex). Lateral cephalograms were used to evaluate lower incisor proclination, while study casts and intraoral photographs were used to evaluate labial and lingual gingival recessions before (T1) and at an average of 4.5 years (T2) after treatment.

RESULTS

No differences in labial recessions on lower incisors were present between the patient groups despite greater lower incisor proclination in the Nonex and DO groups. The Ex group showed no new development of lingual recessions in contrast to the Nonex (eight sites; two subjects) and DO groups (seven sites; three subjects). Severe lingual recessions (increased ≥1 mm) were more present in the Nonex group (five sites; two subjects) compared to the Ex group (no sites). Proclination of lower incisors of 10° or more either by orthodontic tooth movement or displacement of the whole alveolar process increased the risk of lingual gingival recessions 17 times. This was not the case with labial gingival recessions.

CONCLUSIONS

Orthodontic or surgical proclination of lower incisors beyond a 10° limit increases the risk of inducing lingual gingival recessions.

CLINICAL RELEVANCE

During orthodontic treatment, with or without DO, one should avoid proclining lower incisors more than 10° to decrease the risk of gingival recessions.

No association between gingival labial recession and facial type

OBJECTIVE

To evaluate if facial type is a predictor of the development of gingival recession.

METHODS

A cohort of 179 orthodontic patients (76 males, 101 females; age before treatment T S = 12.4 years, SD = 0.8) were followed until 5 years post-treatment (T 5 = 20.7 years, SD = 1.2). The presence of recessions was scored ('Yes' or 'No') by two raters on initial (T S), end of treatment (T 0), and post-treatment (T 5) plaster models. A recession was noted (scored 'Yes') if the labial cemento-enamel junction was exposed. The clinical crown heights were measured at T S, T 0, and T 5 as the distances between the incisal edges and the deepest points of the curvature of the vestibulo-gingival margins. Determination of the facial type was based on the inclination of mandibular plane relative to cranial base (Sella-Nasion/Mandibular Plane) and the proportion of posterior to anterior face heights (PFHs; SGo/NMe × 100 per cent) on pre-treatment cephalograms.

RESULTS

From T 0 to T 5, the number of subjects with recessions increased from 2 (1.1 per cent) to 24 (13.6 per cent), and the number of recession sites increased from 2 to 39. However, most patients had either one or two recession sites. The mean clinical crown height of mandibular incisors increased by 0.86mm (SD = 0.82, P < 0.001). Regression analysis showed that mandibular plane inclination had no effect on the development of gingival recession or on the increase of clinical crown heights of mandibular incisors.

CONCLUSIONS

Facial type is not a predictor of the occurrence of gingival recession.

Iatrogenic Damage to the Periodontium Caused by Orthodontic Treatment Procedures: An Overview

In orthodontic treatment, teeth are moved in to new positions and relationships and the soft tissue and underlying bone are altered to accommodate changes in esthetics and function. Function is more important than esthetics. The speciality of orthodontics has in addition to its benefits, complications as well as risks associated with its procedures. However the benefits outweigh the risks & complications in most of the treatment cases. Few of the unwanted side effects associated with treatment are tooth discolorations, enamel decalcification, periodontal complications like open gingival embrasures, root resorption, allergic reactions to nickel & chromium as well as treatment failure in the form of relapse.

Periodontal consequences of mandibular incisor proclination during presurgical orthodontic treatment in Class III malocclusion patients

OBJECTIVE

To test the hypothesis that periodontal changes are similar between proclined and minimal-changed mandibular incisor position groups during presurgical orthodontic treatment for Class III orthognathic surgery.

MATERIALS AND METHODS

The following measurements were performed before and after presurgical orthodontic treatment of 75 patients (proclination group, 39 subjects; minimal-change group, 36 subjects): clinical crown length, sulcus and bone probing depths, and width of attached gingiva from clinical examination; infradentale-to-MP (perpendicular distance of infradentale to mandibular plane) from examination of lateral cephalograms; and the distance between the cementoenamel junction and alveolar crest from examination of periapical radiographs. Data were compared between the two groups, and a regression analysis was performed to investigate factors affecting the periodontal changes.

RESULTS

In both groups, clinical crown length and bone probing depth increased during presurgical orthodontics (P < .05). Infradentale-to-MP and the width of attached gingiva decreased more in the proclination group than in the minimal-change group (P < .05). Proclination and protrusion of the mandibular incisors, and treatment duration affected the periodontal changes.

CONCLUSIONS

The null hypothesis was rejected. Proclination of the mandibular incisors for decompensation in Class III surgery patients seems to result in labial alveolar bone recession and a decrease in width of attached gingiva. However, the amount of the periodontal recession appeared to be clinically insignificant.

Creating labial bone for immediate implant placement: a minimally invasive approach by using orthodontic therapy in the esthetic zone

Orthodontic extrusion of nonrestorable teeth has been used for almost 20 years as an alternative to bone grafting in preparation for implant placement. Although this technique predictably creates bone and soft tissue, and improves the socket diameter and depth, most of the bone apposition occurs in the marginal alveolar and periapical areas of the extruded tooth. To create more labial bone, the standard orthodontic extrusion technique was modified to apply pressure on the hopeless tooth both coronally and palatally, which allowed bone at the site to develop apically and labially. Gingival thickness on the labial aspect was also increased, and the tissue biotype was improved. A clinical treatment is presented that illustrates the use of this technique.

The inclination of mandibular incisors revisited

OBJECTIVE

To reassess the inclination of lower incisors and evaluate possible associations with gender, age, symphyseal parameters, and skeletal pattern.

MATERIALS AND METHODS

Twelve hundred and seventy-two (605 females, 667 males) cephalograms of untreated subjects of a craniofacial growth study (age: 8-16 years) were evaluated. Correlations between the angulation of the lower incisors and age, symphyseal distances (height, width, and depth), symphyseal ratios (height-width, height-depth), and skeletal angles (divergence of the jaws and gonial angle) were investigated for all ages separately and for both sexes independently.

RESULTS

The inclination of lower incisors increased over age (8 years: girls = 93.9° [95% CI, 92.3°-95.7°], boys = 93.3° [95% CI, 91.8°-94.9°]; 16 years: girls = 96.1° [95% CI, 94.1°-98.2°], boys = 97.1° [95% CI, 95.6°-98.6°]). Inclination of lower incisors correlated with the divergence of the jaws for all ages significantly or highly significantly, except for boys and girls 9 years of age and girls 11 and 12 years of age, for which only a tendency was observed. Similarly, a strong correlation to gonial angle could be observed. No correlation could be found between the inclination of lower incisors and any symphyseal parameters (absolute measurements and ratios), except for symphyseal depth.

CONCLUSION

Lower incisor inclination is linked to the subject's sex, age, and skeletal pattern. It is not associated with symphyseal dimensions, except symphyseal depth. Factors related to natural inclination of lower incisors should be respected when establishing a treatment plan.

Iatrogenic possibilities of orthodontic treatment and modalities of prevention

The benefits of orthodontic treatment are numerous and in most cases, the benefits outweigh the possible disadvantages. Orthodontic treatment can play an important role in enhancing esthetics, function, and self-esteem in patients. However, it carries with it the risks of enamel demineralization, tissue damage, root resorption, open gingival embrasures in the form of triangular spaces, allergic reactions to nickel, and treatment failure in the form of relapse. These potential complications are easily avoidable by undertaking certain precautions and timely interventions by both the orthodontist and the patient. The orthodontist must ensure that the patient is aware of the associated risks and stress the importance of the patient's role in preventing these untoward outcomes. The decision whether to proceed with the orthodontic treatment is essentially a risk-benefit analysis, where the perceived benefits of commencing treatment outweigh the potential risks. This article provides an overview of the iatrogenic possibilities of orthodontic treatment and the role of the patient as well as the orthodontist in preventing the associated risks.

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 β-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.

Orthodontic-periodontics interdisciplinary approach

In this present era, when a significant number of patients seeking orthodontic treatment are adults, importance of multidisciplinary treatment approach cannot be overemphasized. Higher susceptibility of plaque accumulation in patients undergoing orthodontic treatment makes involvement of periodontist almost unavoidable. Also, orthodontic treatment frequently results in undesirable periodontal changes which require immediate attention. More recently, orthodontics has been used as an adjunct to periodontics to increase connective tissue support and alveolar bone height. The purpose of this article is to review the adverse effects of orthodontic treatment on the periodontal tissues and to discuss the mutually beneficial relationship shared between the two specialties.

Gingival recessions and the change of inclination of mandibular incisors during orthodontic treatment

SUMMARY A recent systematic review demonstrated that, overall, orthodontic treatment might result in a small worsening of periodontal status. The aim of this retrospective study was to test the hypothesis that a change of mandibular incisor inclination promotes development of labial gingival recessions. One hundred and seventy-nine subjects who met the following inclusion criteria were selected: age 11-14 years at start of orthodontic treatment (TS), bonded retainer placed immediately after treatment (T₀), dental casts and lateral cephalograms available pre-treatment (TS), post-treatment (T₀), 2 years post-treatment (T₂), and 5 years post-treatment (T₅). Depending on the change of lower incisor inclination during treatment (ΔInc_Incl), the sample was divided into three groups: Retro (N = 34; ΔInc_Incl ≤ -1 degree), Stable (N = 22; ΔInc_Incl > -1 degree and ≤1 degree), and Pro (N = 123; ΔInc_Incl > 1 degree). Clinical crown heights of mandibular incisors and the presence of gingival recessions in this region were assessed on plaster models. Fisher's exact tests, one-way analysis of variance, and regression models were used for analysis of inter-group differences. The mean increase of clinical crown heights (T₀ to T₅) of mandibular incisors ranged from 0.6 to 0.91 mm in the Retro, Stable, and Pro groups, respectively; the difference was not significant (P = 0.534). At T₅, gingival recessions were present in 8.8, 4.5, and 16.3 per cent patients from the Retro, Stable, and Pro groups, respectively. The difference was not significant (P = 0.265). The change of lower incisors inclination during treatment did not affect development of labial gingival recessions in this patient group.

Interfaces between orthodontic and periodontal treatment: their current status

The contextual relationships between orthodontics and periodontology are diverse and complex. While the consequences of orthodontic tooth movements are discussed in terms of possible damage and improvements in the long-term health of periodontal tissues orthodontic treatment of adults is a routine clinical procedure nowadays, even in patients presenting already-damaged periodontal tissues. As developments in both fields have been so rapid, there is a constant need for evidence-based concepts in this interdisciplinary field. The goal of this review was to discuss the latest aspects of interdisciplinary treatment and to reflect on the latest developments in research. A treatment scheme is also presented which aims to facilitate coordination of the orthodontic treatment of patients with periodontal diseases.

An update on periodontic-orthodontic interrelationships

Talking about periodontic-orthodontic interrelationships is related primarily to the 1960s, where a generalized increase in salivary bacterial counts, especially Lactobacillus, had been shown after orthodontic band placement. The purpose of this article is to provide the dental practitioner with basic understanding of the interrelationship between periodontics and orthodontics by means of representing classical studies, and, to give an update on this topic by demonstrating the most recent opinions concerning periodontic-orthodontic interrelationships. Specific areas reviewed are the ability of orthodontic treatment to afford some degree of protection against periodontal breakdown, short-term and long-term effects of orthodontic treatment on the periodontium, and some mucogingival considerations. Topics considering orthodontic treatment in periodontally compromised patients were not included in this review. While past studies have shown that orthodontic treatment can positively affect the periodontal health, recent reviews indicate an absence of reliable evidence for the positive effects of orthodontic therapy on patients’ periodontal status. Periodontic-orthodontic interrelationships are still controversial issues. However, a standard language between the periodontist and the orthodontist must always be established to eliminate the existing communications barrier, and to improve the outcomes of the whole treatment.

Periodontal effects of surgically assisted rapid palatal expansion evaluated clinically and with cone-beam computerized tomography: 6-month preliminary results

INTRODUCTION

Transverse maxillary deficiency is frequently observed in patients who seek orthodontic treatment. In skeletally mature patients, transverse maxillary deficiency can be treated with surgically assisted rapid palatal expansion (SARPE). Forces delivered by the expander produce areas of compression in the periodontal ligament, which could lead to alveolar bone resorption and possible changes in the attachment level. The aim of this prospective clinical study was to evaluate the periodontal effects of SARPE by means of a complete clinical evaluation and cone-beam computerized tomography (CBCT) evaluation.

METHODS

The sample included 14 patients (5 males, 9 females), with a mean age of 23.0 ± 1.9 years (range: 16.4 to 39.7 years). All patients were treated using a bonded Hyrax-type expander, and the mean expansion was 9.82 mm (7.5 to 12.0 mm). All patients had a 1-year retention period. CBCT scans were taken, and periodontal charts were completed at time points T0 (initial) and T1 (6 months after expansion).

RESULTS AND DISCUSSION

SARPE seemed to have little detrimental clinical effects on the periodontium. Radiographic data demonstrated statistically significant changes: a significant decrease in the buccal alveolar bone thickness on most teeth, a significant increase in the palatal alveolar bone thickness on most teeth, a decrease in the buccal alveolar crest level of all canines and posterior teeth, and a tendency toward a decrease in the interproximal alveolar crest level on the mesial aspect of both central incisors.

CONCLUSIONS

SARPE seems to have little detrimental effects on the periodontium clinically. However, radiographic data demonstrated some statistically significant changes, which could eventually have a significant clinical impact on the periodontium.