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1.
External root resorption is one of the most exasperating and least understood clinical problems in orthodontics. Numerous studies have been conducted, attempting to establish the factors causing root resorption of permanent teeth. Considerable variation exists however, in the extent and distribution of root resorption, seen in the orthodontic treatment of apparently similar cases. After an excellent review of the literature, Brezniak and Wassertein (1993) concluded that the most significant disgnostic aid in predicting whether root resorption would occur during orthodontic treatment, is the radiographic evidence of root resorption before treatment. A case is reported, describing the dilemma of orthodontically treating a patient, who had previously experienced trauma to the upper right central incisor, leading to external root resorption.  相似文献   

2.
A case is presented in which combined endodontic and orthodontic therapy was performed in traumatically injured teeth 12 months after an accident. Calcium hydroxide treatment was used to halt any possible resorption during orthodontic treatment. The teeth were repositioned in a desirable manner without any complication by orthodontic treatment. Root canal obturation was accomplished after the completion of active orthodontic treatment. Recall examination 12 months after completion of root canal treatment showed clinical and radiographic evidence of healing.  相似文献   

3.
Radiographic observations show that periapical replacement resorption (PARR) is a frequent and unpredictable sequella of orthodontic movement of permanent maxillary incisors. Only the apical root portion undergoes resorption, and it is subsequently replaced with normal bone. PARR also occurs without orthodontic tooth movement, but these resorptions differ as to type and location. PARR clearly occurs in teeth with vital pulps after orthodontic movement; however, our two cases and a review of 43 other cases indicate that endodontically treated incisors show a statistically significant lesser frequency and severity of apical resorption than untreated teeth. The role the vital pulp plays in this apical resorption is yet to be determined. A hypothetical explanation is offered suggesting that pulpal neuropeptides may be involved in PARR in both vital and endodontically treated incisors. The role calcium hydroxide plays in endodontically treated teeth is also considered.  相似文献   

4.
A subgingival crown-root fracture presents the clinician with a difficult restorative problem, including reaching the fracture line, and is complicated by the need to maintain the periodontal tissues in good health. The treatment options up to now have usually been limited to extrusion of the remaining root with a conventional orthodontic appliance, surgical intraalveolar transplantation of the root or extraction with bridge replacement. In this report, a new method of orthodontic extrusion with attractive magnets is presented. One or two neodymium-iron-boron magnets were attached to the remaining root and a second, larger neodymium-iron-boron magnet was incorporated in a removable appliance. The roots were extruded 2 to 3 mm with a force range from 50 to 240 cN during a treatment period of 9 to 11 weeks. Good force control at short distances, no friction, and no material fatigue of permanent rare earth magnets resulted in successful rapid extrusion. No evidence of soft tissue dehiscences, aberrant tooth mobility, or root resorption was found.  相似文献   

5.
Traumatic intrusion of permanent teeth is a relatively infrequent but serious type of dental injury, due to the complicated picture it involves. Various treatment approaches have been suggested, so far, regarding management of intrusive luxation. Techniques aiming to reposition the intruded tooth include observation for spontaneous reeruption, surgical as well as orthodontic repositioning. However, development of complications such as pulp necrosis, inflammatory root resorption, replacement resorption and ankylosis and loss of marginal bone support makes selection of the most favorable technique controversial. In this paper, a critical review of the existing treatment modalities is attempted and treatment approaches based on diagnostic parameters that are indicative of the severity of an intrusive injury are presented. Recommendations are made after taking into consideration experimental and clinical study findings and observations from other author's and our own clinical experience. Two cases of intrusive luxation in children are presented and management of the dental injuries as well as the complications which occurred are being discussed.  相似文献   

6.
A case is reported in which an intruded incisor was initially treated by an endodontic dressing with calcium hydroxide and then extruded using a removable orthodontic appliance. A follow-up examination seven years after completion of endodontic therapy and bleaching showed a favourable response. A review of the relevant literature indicates that intrusion occurs in five to twelve per cent of luxation cases. In this type of injury maximum damage occurs to the pulp and all supporting structures because the tooth is driven into the alveolar process. Complications which have been reported include: pulp necrosis, apical radiolucencies, partial or total pulp calcification, root resorption (surface, inflammatory or replacement), marginal periodontal bone breakdown, and arrested or disturbed root development. The prognosis for pulp survival after intrusion is much more favourable for teeth with incomplete root formation than for teeth with complete root formation. Treatment options available to bring an intruded tooth into alignment are: to await spontaneous re-eruption which may occur if root formation is incomplete, uncovering of the intruded crown, orthodontic extrusion which is allied with gentle luxation if the tooth does not move, and immediate surgical repositioning.  相似文献   

7.
A case is presented of external cervical resorption detected on routine 6-monthly examination. Following root canal therapy orthodontic extrusion and pericision, the tooth was restored using a radicular retained post and core supporting a porcelain bonded to gold full coverage crown.  相似文献   

8.
This case report describes the treatment of an external root resorption with extensive loss of tooth structure and bone at the labial surface of an upper left central incisor. The area of bone loss and root resorption was surgically exposed and an impression was taken using curing silicone. An individual ceramic insert was fabricated, allowing endodontic retreatment through an artificial root canal. The insert was incorporated using a dentin bonding system and a dual curing luting composite. Following endodontic retreatment and internal bleaching, a ceramic veneer was bonded to the tooth to obtain good esthetics and to improve stability. Twenty months after surgical treatment no further root resorption could be detected radiographically. A shallow residual pocket but no bleeding on probing was found.  相似文献   

9.
M Trope 《Canadian Metallurgical Quarterly》1998,10(8):1005-10; quiz 1012
Attempts have been made to classify root resorption according to its etiology in order to develop more efficient strategies for its treatment. This condition has been identified as resulting from damage to the protective attachment layer (predentin or precementum) of the root combined with inflammation adjacent to the root surface. This article demonstrates a series of treatment strategies focused on the reversal of each manifestation of subattachment root resorption, specifically emphasizing defects that extend apically and localized defects.  相似文献   

10.
Intrusion has been regarded as a controversial topic in the literature. It is apparent from many studies that excessive forces applied in orthodontic treatment might lead to undesirable results such as circulatory disturbances, pulp degeneration, calcification and even necrosis. This study was performed to observe the reaction of pulp and roots following tooth intrusion. Material consisted of four first premolar teeth of two adult patients. One premolar of each patient was intruded orthodontically and the other premolars were taken as controls. The palatal roots of the experimental teeth were cut and examined in scanning electron microscope (SEM) and the pulps of the teeth were examined in transmission electron microscope (TEM). At SEM examination, root surfaces of intruded teeth showed resorption cavities of different diameters and depths. At TEM examination, vascular degeneration was the main change in the pulps of experimental teeth.  相似文献   

11.
Our knowledge of total body bone resorption during growth is limited. The primary purpose of this study was to determine if a commercially available bone resorption assay, developed for measuring human bone resorption, could be used to measure whole body bone resorption in young, growing pigs. A secondary purpose was to evaluate if this method could detect changes in bone resorption in response to certain dental appliances which have been shown to change mandibular and maxillary growth. Five growing 4-month-old male Hanford minipigs (Sus scrofa) were housed in metabolic cages for 24 h, every other day, over a period of 1 month. Three of the animals were fitted with a mandibular protrusive orthodontic appliance. Total 24 h urines were collected in which the concentration of creatinine and collagen type I N-telopeptide crosslinks (NTx, a marker of bone resorption) were measured. The NTx immunoassay was originally developed for the analysis of human urine. Pig bone was powdered, defatted, and decalcified, and the resulting powder digested with bacterial collagenase. The digest was screened for NTx content, in the same fashion as the pig urines. Bone extract and pig urines were cross-calibrated to a standard of adolescent human urine. This allowed calculation of the daily quantity of pig bone resorbed. Daily metabolite excretion was quite variable in these growing animals; for NTx the CV was 31%, for creatinine the CV was 25%. The mean daily quantities of bone resorption ranged between 26 and 46 grams of bone which amounted to 1.2-1.7% of estimated total skeletal mass. The protrusive appliances increased bone resorption significantly during the first two weeks of the trial. In conclusion: the NTx assay can be used to measure bone resorption in pigs; the assay is sensitive enough to indicate changes in bone resorption, such as those caused by an orthodontic mandibular protrusive appliance. During growth, bone resorption varies greatly from day to day. On average, every 24 h, 1.4% of the skeletal mass is resorbed.  相似文献   

12.
BACKGROUND: Delays in the appearance of osteoclasts at compression sites occur after orthodontic appliance reactivation, when this is done during both the period of osteoclast recruitment and the peak expansion in the osteoclast population. This experiment examines osteoclasts and tooth movement in alveolar bone after appliance reactivation coinciding with alveolar bone formation and the time when reactivation osteoclasts first appear (ie, 10 days after initial appliance activation). METHODS: Bilateral orthodontic appliances were activated to mesially tip maxillary molars with 40 cN in 144 rats. After 10 days, all rats were randomized into two groups of 72. Group I had appliances reactivated in precisely the same manner as the first activation. Group II had appliances sham-reactivated. Nine to 12 rats were then sacrificed at 1, 3, 5, 7, 10, and 14 days in both groups (eg, day 1 represents an interval of 11 days after the first appliance activation and 1 day after either sham or real reactivation). Orthodontic movement was measured cephalometrically; changes in osteoclasts and root resorption were assessed at both compression and tension sites histomorphometrically. RESULTS: Teeth in the reactivated group (Group I) displayed linear tooth movement (62.6 micrometers/day), and 0.9 mm tooth movement by day 10. Significant increases in osteoclast numbers, osteoclast surface percentage, and surface per individual osteoclast were evident in these animals by 1 day postreactivation (P <.01). Significant treatment-related increases in root resorption were not evident at compression sites at any time. CONCLUSIONS: These findings indicate that, after appliance reactivation during the time when reactivation osteoclasts appear, a second cohort of osteoclasts can be recruited immediately, along with immediate and substantial tooth movement and no greater risk of root resorption.  相似文献   

13.
Tooth luxations are relatively common. In case of concussion or subluxation the tooth is not displaced. The treatment will consist of relief of the tooth. Most frequent complications are pulp necrosis and obliteration of pulpal tissues. In case of extrusive luxation pulpal tissues and the periodontal ligament are injured. When tooth mobility is increased flexible splinting should be considered. Endodontic treatment is necessary after extrusive luxation of a tooth with completed root formation. Teeth with open apex often show pulpal obliteration after extensive luxation. Lateral luxation is more complex than extrusive luxation since the alveolar bone is also damaged. Repositioning and splinting of the tooth are necessary. When the apical foramen in closed, endodontic treatment will be necessary. Teeth with incomplete root formation will develop pulp obliteration. Following lateral luxation, external root resorption and loss of marginal bone are not infrequent. Intrusive luxation is the type of trauma with most unfavorable prognosis. All intruded teeth will become necrotic and external root resorption and marginal bone loss are frequent. There is no consensus regarding the therapeutic approach. Orthodontic extrusion or surgical mobilisation are possible options. In case of avulsion, both the pulpal tissues and the periodontal ligament are disrupted. Preservation of the vitality of the periodontal ligament covering the root will determine the prognosis of the reimplanted tooth. Therefore the tooth will be repositioned as soon as possible. When this is not possible, milk or a specific solution are most appropriate for tooth conservation. When the reimplanted tooth has complete root formation, devitalization will be performed one week after after repositioning. In case of a tooth with open apex revascularisation can be awaited. Healing of the periodontal ligament will determine prognosis. When a normal ligament is obtained during healing or when surface resorption is obtained, the tooth can be preserved for a long period. When progressive replacement resorption (ankylosis) develops, most teeth can remain in position for about 10 years. When inflammatory resorption develops, the tooth will be lost within a short time.  相似文献   

14.
BACKGROUND: Advances in bonding techniques and materials allow for reliable bracket placement on ectopically positioned teeth. This prospective study evaluates the outcome of forced orthodontic eruption of impacted canine teeth in both palatal and labial positions. METHODS: Eighty-two impacted maxillary canines in 54 patients were included in the study and were observed for 18 to 30 months after exposure. Following exposure by means of a palatal flap or an apically repositioned buccal flap, an orthodontic traction hook, with a ligation chain attached, was bonded to each impacted tooth using a light cured orthodontic resin cement. A periodontal dressing was placed over the surgical site for a period of time. RESULTS: All teeth were successfully erupted. Complications consisted of: failure of initial bond, at the time of surgery, which required rebonding; premature debonding at the time of pack removal and; debonding of brackets during orthodontic eruption. There was no infection, eruption failure, ankylosis, resorption or periodontal defect (pocket greater than 3 mm) associated with any of the exposed teeth. Attached gingiva of less than 3 mm was seen in only two of the buccally positioned canines (9%). CONCLUSION: Forced orthodontic eruption of impacted maxillary canines with a well bonded orthodontic traction hook and ligation chain, used in conjunction with a palatal flap or an apically repositioned labial flap, results in predictable orthodontic eruption with few complications.  相似文献   

15.
Mucoperiosteal flaps are used to access the bone and root surface in a wide range of periodontal procedures and in implant surgery. We have demonstrated that the mucoperiosteal surgical flap of the rat mandible produces a transient burst of alveolar bone resorption similar to the clinical observations in humans. This resorptive activity, when coupled with local irritation factors, may cause confined alveolar bone loss. Recently, we have demonstrated that an amino bisphosphonate, which is used in preventing systemic bone resorption in osteoporosis and other bone diseases, reduces alveolar bone resorption in the rat model when administered systemically. In this study we evaluated the effect of local delivery of the amino bisphosphonate on bone resorption associated with mucoperiosteal flaps. Following mucoperiosteal flap elevation in the premolar and molar region of the rat mandible, a surgical pellet soaked with amino bisphosphonate was locally applied on the exposed bone surface and covered by flap. The results show that local delivery of amino bisphosphonate reduces significantly alveolar bone resorption activated by mucoperiosteal flap surgery. This study suggests that local application of amino bisphosphonate can be used as an adjunct in therapy for reducing bone resorption following surgery.  相似文献   

16.
Adjacent anomalous or missing maxillary lateral incisors have been implicated in the aetiology of palatally displaced canines by not providing proper guidance to the canine during its eruption. However, a recent review of the literature suggests that the aetiology of palatally displaced canines is genetic in origin. The aetiology of labially impacted canines differs, being due to inadequate arch space. Vertex occlusal radiographs have been recommended for localization but have limitations, and a case is illustrated where this radiograph is deceptive. The prevention/interception of a palatally displaced canine by the extraction of the deciduous canine is best carried out as early as the displacement is detected, mostly soon after 10 years of age. Usually, prevention/interception will avoid the surgical and orthodontic treatment needed to align a palatally impacted canine and may help prevent resorption of the adjacent incisor root. Suspicions that an impaction could occur or has occurred arise a) before the age of 10 years if there is a familial history and/or the maxillary lateral incisors are anomalous or missing; b) after the age of 10 years if there is asymmetry in palpation or a pronounced difference in eruption of canines between the left and right side; or the canines cannot be palpated and occlusal development is advanced; or, the lateral incisor is proclined and tipped distally; and, on a panoramic radiograph of the late mixed dentition if the incisal up of the canine overlaps the root of the lateral incisor.  相似文献   

17.
This study was undertaken to evaluate clinically and histologically root resorption in extracted human second molars in close proximity to non-erupted third molars. The control group consisted of extracted second molars that were proximal to fully erupted third molars. Eight out of the 11 teeth in the study group presented different degrees of radiographic root resorption, nine presented clinical resorption, and all 11 had histologic evidence of root resorption. In the control group, no signs of root resorption were seen radiographically or clinically. Histologically, limited sites of resorption were identified in all teeth, which were partially repaired by cellular cementum. Histologic observation of study specimens revealed root surface resorption in 10 out of the 11 teeth, one showing replacement resorption as well. Inflammatory resorption was observed in the three most advanced cases in the study group. Reparative cementum partially lining resorbed areas was evident in all teeth with surface resorption. Within the limits of this study, radiographic identification of distal root resorption of second molars in close proximity to non-erupted third molars appears reliable. The findings may support the hypothesis that the presence of a non-erupted third molar in close proximity to the distal root of the second results in root resorption.  相似文献   

18.
Pre-prosthetics, as a part of orthodontic treatment in adults has gained increasing importance during recent years. Through coordinated orthodontic, prosthetic and periodontal treatment plans, patients with partial dentition can be offered further treatment possibilities. Such planning would allow for fixed prosthetic treatment possibilities and the survival of critical teeth. They would provide for better aesthetics and avoid functional disturbances. The aim of the present study was to present reports of patients treated by coordinated work at the Dental School of Hamburg University. In patients with partial dentition, premolars were uprighted and distally moved and molars were extruded to be used as abutments for fixed prosthetic reconstructions. Following trauma, the position of the remaining anterior teeth was improved to provide for optimal aesthetics after prosthetic treatment. Extraction of a subalveolarly fractured tooth is avoided through root extrusion and post-core reconstruction. The results demonstrate the advantages of pre-prosthetic treatment as regards stability, aesthetics and function. With the help of pre-prosthetic orthodontic treatment, complicated treatment situations could be handled more successfully than would have been the case without such treatment.  相似文献   

19.
Root resorption is a challenging problem for dental practitioners. This paper presents a simple, organized classification of the types of root resorption and a discussion of the clinical and radiographic features of each. Treatment requirements or options are given, along with prognosis relative to the type of resorptive defects. Knowledge of these entities and of the modalities of treatment for each can assist the dentist in providing the appropriate care to maximize retention of these affected teeth.  相似文献   

20.
Many treatment plans require a dental practitioner to maintain the entire labial cortical plate of bone when removing an anterior maxillary tooth. A tooth with an undermined root secondary to an endodontic perforation or internal (Idiopathic) resorption can present a surgical challenge to the general practitioner. This article describes a new technique for extracting a severely undermined anterior maxillary tooth while maintaining the entire labial cortex of bone.  相似文献   

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