Periodontal response after tooth movement into intrabony defects

Intrusion of migrated incisors with infrabony defects in adult periodontal patients

This report describes the orthodontic treatment of 10 adult patients who had severe periodontal disease, with migration and radiological evidence of an infrabony defect on a maxillary central incisor. Orthodontic tooth movement, using light and continuous forces, was initiated 7 to 10 days after periodontal surgical therapy. Mean orthodontic treatment time was 10 months. Before surgery and at the end of orthodontic treatment, the following parameters were registered clinically and with standardized intraoral radiographs: probing depth, clinical crown length, marginal bone level, bone defect radiological dimension, and root length. Comparison of pre- and posttreatment values showed a statistically significant improvement for all parameters without a remarkable decrease of root length. The mean residual probing depth was 2.80 mm, and the mean intrusion of the incisors was 2.05 mm. Moreover, radiographs showed a reduction of the infrabony defects. These results show the efficacy of a combined orthodontic-periodontal approach. Intrusive movement, after proper periodontal surgical therapy, can positively modify both the alveolar bone and the soft periodontal tissues.

Orthodontic tooth movement enhances bone healing of surgical bony defects in rats

BACKGROUND

The question of whether the repair of an alveolar bony defect can be enhanced by orthodontic tooth movement was addressed.

METHODS

Alveolar bone defects were created in 52 Wistar male rats anterior to both maxillary first molars. After 1 week of healing, orthodontic protraction was applied for 2 weeks on the right side, resulting in mesial tipping and displacement movement. Subsequently, a retention appliance was inserted for 1 week. The left side served as the untreated (control) group. Vital bone staining (procion brilliant red H-8) was administered before and after orthodontic traction. Histomorphometric analysis was performed on 62 hemimaxillae using UV confocal microscopy and an imaging program. The total area of the bony defect was divided into 4 equal quadrants, and the area of bony apposition in each quadrant was measured.

RESULTS

The total area of bony apposition was 6.5-fold larger in the treated (26.41 x 10(4) +/- 28.92 x 10(4) microm2) than in the control group (4.07 x 10(4) +/- 2.82 x 10(4) microm2), approaching statistical significance (P = 0.065). The treated occlusal quadrants demonstrated highly significant (P= 0.010), greater bone apposition compared to the control group (13.8-fold) and to the treated apical quadrants (P= 0.04, 5-fold).

CONCLUSIONS

This study confirms that orthodontic tooth movement is a stimulating factor of bone apposition. A conversion in the repair pattern of the bony defect from apicoocclusal in the control group (no tooth movement) to occlusoapical in the treated group (with tooth movement) further supports the linkage between tooth movement and enhanced bone deposition. Clinical implication suggests incorporation of orthodontic tooth movement in regenerative therapy.

Endodontic-orthodontic relationships: a review of integrated treatment planning challenges

Literature review There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions. This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment. This paper reviews the literature based on the definition of endodontics and the scope of endodontic practice as they relate to common orthodontic-endodontic treatment planning challenges. Literature data bases were accessed with a focus on orthodontic tooth movement and its impact on the viability of the dental pulp; its impact on root resorption in teeth with vital pulps and teeth with previous root canal treatment; the ability to move orthodontically teeth that were endodontically treated versus nonendodontically treated; the role of previous tooth trauma; the ability to move teeth orthodontically that have been subjected to endodontic surgery; the role of orthodontic treatment in the provision for and prognosis of endodontic treatment; and, the integrated role of orthodontics and endodontics in treatment planning tooth retention. Orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation. The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism. The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement. The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries. Pulps in teeth with incomplete apical foramen, whilst not immune to adverse sequelae during tooth movement, have a reduced risk for these responses. Teeth with previous root canal treatment exhibit less propensity for apical root resorption during orthodontic tooth movement. Minimal resorptive/remodelling changes occur apically in teeth that are being moved orthodontically and that are well cleaned, shaped, and three-dimensionally obturated. This outcome would depend on the absence of coronal leakage or other avenues for bacterial ingress. A traumatized tooth can be moved orthodontically with minimal risk of resorption, provided the pulp has not been severely compromised (infected or necrotic). If there is evidence of pulpal demise, appropriate endodontic management is necessary prior to orthodontic treatment. If a previously traumatized tooth exhibits resorption, there is a greater chance that orthodontic tooth movement will enhance the resorptive process. If a tooth has been severely traumatized (intrusive luxation/avulsion) there may be a greater incidence of resorption with tooth movement. This can occur with or without previous endodontic treatment. Very little is known about the ability to move successfully teeth that have undergone periradicular surgical procedures. Likewise, little is known about the potential risks or sequelae involved in moving teeth that have had previous surgical intervention. Especially absent is the long-term prognosis of this type of treatment. During orthodontic tooth movement, the provision of endodontic treatment may be influenced by a number of factors, including but not limited to radiographic interpretation, accuracy of pulp testing, patient signs and symptoms, tooth isolation, access to the root canal, working length determination, and apical position of the canal obturation. Adjunctive orthodontic root extrusion and root separation are essential clinical procedures that will enhance the integrated treatment planning process of tooth retention in endodontic-orthodontic related cases.

Interrelationship between periodontics and adult orthodontics

The purpose of this review article is to provide the dental practitioner with an understanding of the interrelationship between periodontics and orthodontics in adults. Specific areas reviewed are how periodontal tissue reacts to orthodontic forces, influence of tooth movement on the periodontium, effect of circumferential supracrestal fiberotomy in preventing orthodontic relapse, effect of orthodontic bands on the periodontium, specific microbiology associated with orthodontic bands, mucogingival considerations and time relationship between orthodontic and periodontal therapy. In addition, the relationship between orthodontics and implant restorations (e.g., using dental implants as orthodontic anchorage) will be discussed.

Infrabony pockets and reduced alveolar bone height in relation to orthodontic therapy

Experimental animal studies have shown that orthodontic movement of teeth into infrabony pockets may be detrimental to the periodontal attachment. After elimination of subgingival plaque infection in the experimental animals, no additional loss of connective tissue attachment occurred. An experimental model has shown that a tooth with normal periodontal support can be orthodontically moved into an area of reduced bone height with maintenance of height of connective tissue attachment level and alveolar bone support. The results from these experimental studies have been tested clinically.

Guided tissue regeneration associated with orthodontic therapy

Guided tissue regeneration (GTR) to enhance genuine new periodontal attachment may improve preorthodontic conditions for moving teeth into infrabony defects or for vertical movements of teeth with reduced bone support. The possible benefits of GTR for combined periodontal/orthodontic therapy are discussed and substantiated with preliminary experimental findings.

Periodontal tissue response to orthodontic movement of teeth with infrabony pockets

The aim of this study was to evaluate the effect of orthodontic tooth movement on the level of the connective tissue attachment in sites with infrabony pockets. The experiment was carried out in four beagle dogs. The second and fourth premolars were extracted. After healing, angular bony defects were prepared at the mesial aspect of the third premolars. The exposed root surface was scaled and planed, and a notch was prepared at the bottom of the defect. Plaque-collecting cotton floss ligatures were placed around the neck of the teeth and maintained in situ for 3 weeks, followed by an additional 2 months of plaque accumulation before the orthodontic tooth movement was initiated. In each dog, one premolar was moved away from the angular bony defect and one premolar into and through the angular bony defect. The maxillary third premolars served as control teeth and were not subjected to orthodontic tooth movement. After orthodontic treatment (5 to 6 months), the teeth were stabilized for a period of 2 months before biopsy sampling. Clinical, radiographic, and histologic evaluations revealed that it was possible to establish and maintain an infrabony pocket with a subcrestal, plaque-induced inflammatory lesion during the entire course of the study. While the control teeth had maintained their attachment levels, all but one of the orthodontically moved teeth showed additional loss of attachment.(ABSTRACT TRUNCATED AT 250 WORDS)

[The orthodontic treatment of deep bite in adults--a comparison of the straight-wire appliance and the segmented arch technic]

The purpose of the study was to analyse and compare deep overbite correction in adult patients carried out by a straight wire appliance and the segmented arch technique as recommended by Burstone. The sample comprised 50 adult, deep bite patients, 25 each treated with straight wire appliance and segmented arch technique. Plaster casts and lateral cephalograms made before and immediately after finishing treatment were analysed. Both techniques were successful in overbite correction; overbite reduction amounted to 3 to 3.5 mm. The straight wire appliance group demonstrated predominantly molar extrusion and as a result posterior mandibular rotation. A slight intrusion of 1 mm was seen in the lower incisor area. The segmented arch technique resulted in an incisor intrusion of 1.5 mm in the upper and 1.7 mm in the lower jaw. No substantiate extrusion in the molar area was found. The advantages of this technique are discussed.

Cementum thickness and mesial drift

Cementum thickness increases uniformly with age, and questionably from functional stimulation due to tensional forces. Mesial drift of teeth results in tensional forces on distal root surfaces. This study evaluated whether there was any discernible effect on cementum thickness related to mesial drift in humans. The material consisted of maxillary and mandibular bicuspids and molars with their surrounding periodontia from 5 humans (mean age at death, 48.6 years). The teeth and tissues had been sectioned histologically in a mesio-distal plane, and the analysis for each tooth was done using 3 step-serial sections from the mid-buccolingual region. On the mesial and distal surface of each tooth, cementum thickness was measured in microns at 3 defined locations at a level representing the mid-point of root length for bicuspids and molars. Means from the measurements on mesial and distal surfaces were compared using descriptive and and inferential statistical methods. For each individual tooth analyzed, the cementum was thicker on the distal surface (range greater, 32-107%; mean, 69%). The statistical comparisons showed that cementum thickness on the distal surface was significantly greater for bicuspids (mesial, 135 microns: distal, 216 microns), molars (mesial, 154 microns: distal, 284 microns), and all teeth combined (mesial, 154 microns: distal, 284 microns). The magnitude of this difference became greater with increasing age. It was concluded that cementum thickness was markedly greater on the distal surfaces of teeth from adult humans, and that this may be due to functional stimulation from mesial drift over time.

[Correlations of orthodontics and periodontics]

Periodontics and orthodontics are correlated with one other in many ways. For instance, periodontal conditions have to be considered in the orthodontic treatment of adults, special orthodontic measures are taken to enhance a periodontal treatment, and when periodontal surgery is performed for the prevention of relapse or the disimpaction of teeth. Dental practitioners working in the field of orthodontics should have a sound understanding of the biology and pathology of the periodontium in order to avoid causing periodontal lesions, or when lesions are present, how best to determine prognosis and differential treatment.

New attachment through periodontal treatment and orthodontic intrusion

The present study was performed to investigate the tissue reaction related to orthodontic intrusion of teeth with a reduced periodontium and further to evaluate the influence of oral hygiene on this reaction. In each of five Macaca fascicularis monkeys, periodontal tissue breakdown was induced around the premolars and the upper incisors by placing orthodontic elastic ligatures around the teeth. The breakdown procedure was continued until a minimum of four pockets could be measured on probing. Following removal of the elastics, a flap operation was performed. The pocket epithelium and granulation tissue were excised. During the surgical procedure, a notch was placed just above the bone. The teeth were divided postoperatively into four groups according to treatment: group 1 = flap operation, no oral hygiene program; group 2 = flap operation plus oral hygiene program three times per week; group 3 = flap operation plus intrusion, no oral hygiene program; and group 4 = flap operation plus intrusion plus oral hygiene. Groups 3 and 4 were subdivided into two observation periods. A total of 60 teeth corresponding to 120 approximate surfaces were studied. The animals were killed with perfusion; histologic sections were produced and stained alternatively with hematoxylin and eosin, and van Gieson's solution. The histologic analysis showed that new cementum formation and new collagen attachment were observed following the surgical procedure if the oral hygiene was maintained, but also demonstrated that the intrusion improved the quantity of new attachment if carried out under healthy conditions. New attachment was a consistent finding in group 4, but varied from 0.7 to 2.3 mm. In case of intrusion without oral hygiene, the results varied from moderate new attachment to an aggravation of the periodontal bone loss. On the basis of the results presented here, the combination of periodontal treatment and orthodontic intrusion seems to be a method by which improvement of the periodontal condition can be obtained, provided that both the biomechanical force system and the oral hygiene are kept under control.

Tissue reaction following application of extrusive and intrusive forces to teeth in adult monkeys

Intrusion has been regarded as a very controversial topic in the orthodontic literature. Although it seems a logical way to handle deep overbite in adult patients who have elongated teeth, reports on iatrogenic damage have led to the suggestion of alternative methods. Considering the disadvantages of these alternatives, it seems reasonable, however, to improve our knowledge of tissue reaction as related to intrusion. Three Macaca fascicularis monkeys were used for the experiment. By means of a segmented arch approach, the upper incisors and the four first premolars were submitted to forced eruption for 8 weeks followed by 12 weeks of intrusion. A split-mouth technique was used to study the influence of oral hygiene on the tissue reaction. On the right side of the mouth, the teeth were brushed with chlorhexidine three times per week. On the left side, no oral hygiene was performed. After intrusion of the teeth, a 1-to-14 day retention period with passive appliance preceded the killing of the monkeys. A buccolingual hematoxylin- and eosin-stained serial section was produced, and soft- and hard-tissue reactions described. It appeared that the hygiene program could limit but not prevent gingival inflammation. There was, however, a marked difference in the histologic picture of the marginal bone on the two sides. On the hygiene side, clear signs of bone deposited during forced eruption were still present. This was not the case on the nonhygiene side. The extension of bone resorption was also different on the two sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Orthodontic therapy in patients with juvenile periodontitis: clinical and microbiologic effects

The correction of malocclusions in juvenile periodontitis (JP) patients completing periodontal therapy is a problem of increasing clinical concern to orthodontists, since many teeth with severe alveolar bone loss in these patients can now be successfully treated without extraction. In this report, fixed edgewise orthodontic therapy was carried out after the completion of periodontal therapy on four JP patients. The orthodontic therapy included extensive intrusion of teeth severely affected by JP. Phase-contrast microscopic analysis of subgingival plaque from orthodontically treated teeth was used to monitor longitudinally the effects of fixed orthodontic bands on the subgingival flora and also to monitor the efficacy of topical and systemic antimicrobial therapy aimed at suppression of suspected periodontopathic bacteria. Orthodontic movement was completed on most periodontally compromised teeth without significant evidence of additional deterioration in periodontal status. However, within the first 6 months of orthodontic band placement, all patients had significant increases in the number of spirochetes and motile rods in their subgingival flora. Three of the patients also developed high levels of crevicular polymorphonuclear leukocytes around orthodontically treated teeth, indicating significant subgingival inflammation. Intensive antimicrobial measures, including topical inorganic salt applications and systemic tetracycline, were helpful in limiting clinical inflammation and subgingival colonization by periodontopathogens during orthodontic therapy. The results demonstrate that successful orthodontic repositioning can be carried out in treated JP patients. In addition, bacteriologic monitoring and chemotherapeutic suppression of periodontal pathogens may be valuable in the prevention of further destructive periodontal disease activity in periodontitis patients undergoing orthodontic therapy.