Periodontal concerns associated with the orthodontic treatment of impacted teeth

Optimal tooth sectioning using a surgical handpiece and elevator: a finite element study of horizontally deeply impacted mandibular third molars

OBJECTIVES

To conduct a finite element analysis of the impact of different variables on tooth sectioning efficiency and trauma to surrounding tissues when utilizing high-speed surgical handpieces and elevators.

METHODS

CBCT data from the horizontally impacted third mandibular molar (M3M) of a patient were utilized to establish digital models of the M3M, adjacent M2M, and surrounding bone. To simulate tooth sectioning, a 3D finite element model was established with the following variables: remaining tooth tissue thickness (1-5 mm), tooth section fissure width (1-3 mm), elevator depth in fissure (2-6 mm), elevator position (buccal, lingual, central), elevator width (2-5 mm), and application of force (rotating, levering). Using this model, the distribution of stress on the M3M and the surrounding tissue was assessed while measuring tooth sectioning efficiency and trauma to the surrounding tissue.

RESULTS

Factors associated with uniform stress at the site of sectioning included thin (≤ 3 mm) remaining tooth tissue, appropriate fissure width (~ 2 mm), a wide (≥ 4 mm) elevator, and central elevator positioning. Levering the elevator yielded greater stress on the M3M than rotating force. Greater sectioning efficiency was associated with increased stress placed on the distobuccal side of M2M.

CONCLUSIONS

Tooth sectioning efficiency can be improved by adjusting the high-speed surgical handpiece and elevator. However, it is important to remain attentive to the trauma to which adjacent teeth are exposed during this process.

CLINICAL SIGNIFICANCE

These results offer guidance for approaches to improving operator efficiency and reducing trauma to surrounding tissues during tooth sectioning.

Post-trauma complex orthodontic approach: the impact of psychological issues of bullying on treatment decision

Objective:

This article aims to discuss the multidisciplinary approach required in the treatment of cases of impaction and ankylosis of permanent teeth, associated with a history of trauma, considering the psychological state of the child and family when faced with a traumatic case of bullying, by reporting the complex treatment of a central incisor needing to be orthodontically moved across the midline.

Conclusion:

This clinical case was a major challenge, which included complex multidisciplinary procedures. Results and stability after 26 months of retention indicated successful orthodontic space closure of two maxillary teeth, without the use of implants or prostheses, in an adolescent patient who had a history of dental trauma, alveolar bone loss, and an uncertain initial prognosis.

Orthodontic Traction of Impacted Canine Using Cantilever

The impaction of the maxillary canines causes relevant aesthetic and functional problems. The multidisciplinary approach to the proper planning and execution of orthodontic traction of the element in question is essential. Many strategies are cited in the literature; among them is the good biomechanical control in order to avoid possible side effects. The aim of this paper is to present a case report in which a superior canine impacted by palatine was pulled out with the aid of the cantilever on the Segmented Arch Technique (SAT) concept. A 14.7-year-old female patient appeared at clinic complaining about the absence of the upper right permanent canine. The proposed treatment prioritized the traction of the upper right canine without changing the occlusion and aesthetics. For this, it only installed the upper fixed appliance (Roth with slot 0.018), opting for SAT in order to minimize unwanted side effects. The use of cantilever to the traction of the upper right canine has enabled an efficient and predictable outcome, because it is of statically determined mechanics.

[Reason for failure in the treatment of impacted and retained teeth]

The positioning of an impacted or retained tooth in either children or adults presents a real challenge for the two practitioners involved, the orthodontist and the surgeon in charge of the surgical exposure. The maxillary canine is the tooth most often impacted in the anterior segment, with a prevalence of 2% in the general population. One can understand, therefore, the functional and esthetic challenge for the surgical-orthodontic team whose aim will be to reposition the impacted or retained tooth in the arch. A large number of mistakes must be avoided in order to achieve a satisfactory result for both the patient and the practitioner. Modern imaging techniques should be used to obtain a precise diagnosis of the location of the tooth and to perform surgery which will spare the tooth in question as well as the surrounding anatomic structures. The directions and forces of the traction used will need to be carefully thought out in order to move the tooth into its final position on the arch in optimal conditions. The periodontal setting will be optimized and checked at every step of the treatment. The aim, in fact, is to anticipate the onset of periodontal problems on the grounds that prevention is easier than cure.

Orthodontic traction of impacted upper central incisors related to mesiodens

Although maxillary central incisors impaction is not a high frequent clinical condition, it is responsible for some undesirable aspects of patients smile from esthetic and functional points of view. There are some etiologic factors associated to this dental disturbance but the scientific literature is consensual on determining the importance of the early diagnosis and proper intervention. This manuscript consists on the case report of a 10 years old boy with Class I malocclusion, who showed during the mixed dentition phase, impaction of maxillary central incisors related to deciduous teeth retention and due to the presence of 2 mesiodens. The treatment proposed involved the surgical removal of the mesiodens, bonding of orthodontic accessories to the impacted incisors crowns followed by orthodontic traction with a removable orthodontic appliance. Regardless the development stage of the dentition was not ideal for this intervention, once the diagnosis should have been done as earlier as possible, favorable esthetic and functional results were attained.

Surgical-orthodontic treatment of Class III malocclusion with agenesis of lateral incisor and unerupted canine

INTRODUCTION

Orthodontic-surgical treatment was performed in patient with skeletal Class III malocclusion due to exceeding mandibular growth. Patient also presented upper and lower dental protrusion, overjet of -3.0 mm, overbite of -1.0 mm, congenital absence of tooth #22, teeth #13 and supernumerary impaction, tooth #12 with conoid shape and partly erupted in supraversion, prolonged retention of tooth #53, tendency to vertical growth of the face and facial asymmetry. The discrepancy on the upper arch was -2.0 mm and -5.0 mm on the lower arch.

METHODS

The presurgical orthodontic treatment was performed with extraction of the teeth #35 and #45. On the upper arch, teeth #53, #12 and supernumerary were extracted to accomplish the traction of the impacted canine. The spaces of the lower extractions were closed with mesialization of posterior segment. After aligning and leveling the teeth, extractions spaces closure and correct positioning of teeth on the bone bases, the correct intercuspation of the dental arch, with molars and canines in Angle's Class I, coincident midline, normal overjet and overbite and ideal torques, were evaluated through study models. The patient was submitted to orthognathic surgery and then the postsurgical orthodontic treatment was finished.

RESULTS

The Class III malocclusion was treated establishing occlusal and facial normal standards.

Long-term periodontal response to orthodontic treatment of palatally impacted maxillary canines

One of the most important aspects to take into consideration when evaluating the outcome of treatment of impacted maxillary canines is the final periodontal status. The aim of the present study was to evaluate the long-term periodontal response of palatally impacted maxillary canines aligned using a codified procedure and the 'Easy Cuspid' compared with contralateral spontaneously erupted teeth. The periodontal conditions of the adjacent teeth were also considered. From an initial sample of 124 patients, 33 patients (24 females and 9 males) were selected. All patients who had undergone surgical orthodontic treatment conducted in accordance with a standardized protocol were recalled for follow-up at an average of 4.6 years after the end of treatment. The average treatment time was 29 months and the mean eruption time of the previously impacted tooth was 3.1 months. The average probing depth values showed no significant clinical differences. Probing depths recorded at the vestibular surface of the lateral incisor (P < 0.05) and at the midpalatal/midlingual aspect of the first premolar were statistically significant in comparison with the control elements. Student's t-test was used to compare the test and control group values. Coefficient of reliability was set at P < 0.05. The use of a closed-flap surgical technique in association with a codified orthodontic traction system (Easy Cuspid) allowed alignment of palatally impacted canines without damage to the periodontium.

Initial Vertical and Horizontal Position of Palatally Impacted Maxillary Canine and Effect on Periodontal Status Following Surgical-Orthodontic Treatment

Objective: To evaluate the impact of surgical-orthodontic treatment and the initial vertical and mesiodistal position of palatally impacted maxillary canines on the periodontal health of impacted canines and adjacent teeth.

Materials and Methods: The study group consisted of 32 patients with unilateral palatally impacted maxillary canines. The initial position of the impacted canines was assessed on panoramic images. The treatment protocol of the impacted canines included surgical exposure with the closed-eruption technique and fixed orthodontic appliances.

Results: A significant increase in pocket depth was found at the canine mesiopalatal point after surgical-orthodontic treatment. Also, a correlation was found between the initial mesiodistal and vertical position of the impacted canine and the posttreatment periodontal status of the impacted canine, the adjacent lateral incisor, and the first premolar.

Conclusions: A combined surgical-orthodontic approach in the treatment of impacted maxillary canines produces clinically acceptable periodontal conditions. The average increase in pocket depth was less than 4 mm and clinically unimportant for most patients.

Local osteoprotegerin gene transfer to periodontal tissue inhibits lipopolysaccharide-induced alveolar bone resorption

BACKGROUND AND OBJECTIVE

Osteoclastogenesis is primarily activated by receptor activator of nuclear factor kappaB ligand (RANKL) and is inhibited by osteoprotegerin (OPG). A previous study demonstrated that local OPG gene transfer to periodontal tissue inhibited RANKL-mediated osteoclastogenesis and experimental tooth movement. In the present study, we tested the hypothesis that local OPG gene transfer to the periodontium can neutralize RANKL activity induced by lipopolysaccharide injection, thereby inhibiting osteoclastogenesis and diminishing alveolar bone resorption in experimental periodontal disease.

MATERIAL AND METHODS

Seven-week-old male Wistar rats received an injection of lipopolysaccharide or phosphate-buffered saline in the palatal gingiva of the upper first molars on both the right and left sides. An inactivated haemagglutinating virus of Japan (HVJ) envelope vector containing a mouse OPG expression plasmid [pcDNA3.1(+)-mOPG] or mock vector was injected periodically into the palatal periodontal tissue of the upper first molars.

RESULTS

Lipopolysaccharide injection induced severe periodontal bone resorption. Local OPG gene transfer induced OPG production, and osteoclastogenesis was inhibited. Local OPG gene transfer significantly decreased alveolar bone resorption.

CONCLUSION

Osteoprotegerin gene transfer to periodontal tissue inhibited osteoclastogenesis and alveolar bone resorption in lipopolysaccharide-induced experimental periodontal disease.

Labially displaced ectopically erupting maxillary permanent canine: interceptive treatment and long-term results

This case report demonstrates how extracting a maxillary deciduous canine affects the eruption path of a labially displaced ectopically erupting permanent canine. A long-term follow-up is presented, and the biologic mechanisms are discussed.

Surgical and orthodontic treatment of an impacted permanent incisor: case report

This case report presented a combined surgical/orthodontic treatment of an impacted permanent incisor of a 10-year-old boy. Trauma to the primary dentition caused the impaction of the maxillary left permanent central incisor. Application of push coil spring between the adjacent teeth created space for the impacted tooth. A button with an extension of ligature wire was bonded to the maxillary left permanent central incisor to bring it into the arch. The maxillary left permanent central incisor was brought to its proper position after 16 months of active orthodontic treatment.

Success rate and duration of orthodontic treatment for adult patients with palatally impacted maxillary canines

This study was undertaken to examine the success rate and the length of orthodontic treatment of impacted maxillary canines in adult patients. A sample of 19 adults (mean age, 28.8 +/- 8.6 years; range, 20-47 years), who had been treated for a total of 23 impacted maxillary canines, was compared with a younger control group (mean age, 13.7 +/- 1.3 years; range, 12-16 years). The control subjects were chosen for a similar degree of impaction difficulty by carefully matching the positions of the impacted canines in the 3 planes of space. The success rate among the adults was 69.5% compared with 100% among the younger controls. The lower success rate was due to 5 canines that had failed to erupt and 2 canines that had been partially extruded but could not be aligned in the arch. The duration of treating the overall malocclusion of the adults and young subjects did not materially differ. However, the adults showed significant increases in the duration and number of treatment visits required for resolving the canine impaction, in both the simpler and the more difficult cases. When further divided by age, all the failed canines were found in the older (over 30) adult subgroup. It was concluded that the prognosis for successful orthodontic resolution of an impacted canine in an adult is lower than that in a younger patient and that the prognosis worsens with age. Furthermore, when such treatment is undertaken, its successful completion should be expected to take considerably longer.

The conservative approach to managing unerupted lower premolars -- two case reports

General dental practitioners frequently refer patients with unerupted premolars for specialist management. The frequency of unerupted lower second premolars in 15-year-old children has been cited as high as 9.7%. Two cases are discussed involving unilateral unerupted premolars, which initially appear to be in unfavourable positions. The first patient was referred at 16 years of age and presented with an unerupted lower left first premolar positioned along the lower border of the mandible. The second patient presented with an unerupted distally inclined, horizontally positioned second premolar impacting on the roots of the first permanent molar. Both cases were reviewed without any treatment, and both premolars erupted into excellent positions. This raises important questions concerning the possible treatment options for such teeth as well as the timing of any interceptive treatment. In cases where premolars are unerupted or impacted, a multidisciplinary approach is indicated involving orthodontics, paedodontics and oral surgery to establish the optimal treatment plan.