Calcifying odontogenic cyst resembling clinical signs of vertical root fracture of a maxillary canine

BACKGROUND

Calcifying odontogenic cyst (COC) can be misdiagnosed as a lesion of endodontic origin when it is in close proximity to the periradicular tissue, and pulp sensibility tests are indispensable for differential diagnosis. However, when the adjacent teeth are necrotic or already endodontically treated, diagnosis becomes challenging.

CASE DESCRIPTION

In this case report, a maxillary canine with an inadequate root canal treatment was considered as the source of an endodontic infection. Eight months after the retreatment, the patient sought treatment for a buccal intraoral swelling and a deep periodontal pocket and was referred for cone-beam computed tomography with a provisional diagnosis of a vertical root fracture. The tomography revealed an extensive lesion buccally to the roots of the canine and the adjacent vital lateral incisor. An unusual extended external resorption of the root of the vital lateral incisor was also evident. This finding shifted the diagnostic thinking toward a lesion of nonendodontic origin. The lesion was surgically enucleated, and the histopathologic examination confirmed the diagnosis of a COC.

PRACTICAL IMPLICATIONS

Clinicians always must bear in mind the chance of a nonendodontic lesion masquerading as a lesion of endodontic origin. Cone-beam computed tomography should be considered in cases of doubt or in lesions refractory to endodontic treatment, as it can provide information on the clinicopathologic features of the lesion.

The Effect of Partial Corticotomy on the Rate of Maxillary Canine Retraction: Clinical and Radiographic Study

The study aimed to evaluate, clinically and radiographically, the effect of partial corticotomy of the buccal plate distal to the canine on the rate of maxillary canine retraction. A clinical trial with the split-mouth design was conducted among twenty orthodontic patients, recommended for first premolar extraction with an age range from 13 to 21 years, selected from patients seeking orthodontic treatment in private dental clinics in Jeddah, Kingdom of Saudi Arabia. After extraction of the maxillary right and left first premolar, partial corticotomy was performed distal to the canine on the right side. The canine retraction was carried out with a power chain on both sides extended between the canine and the maxillary first molar. The data collected from the current study were tabulated and statistically analyzed using an independent sample t-test with p < 0.05 considered statistically significant. The rate of canine retraction was significantly higher on the corticotomy side than the control side (p < 0.05). Under the limitations of the present study, it can be concluded that the technique of partial corticotomy of the buccal plate distal to the canine is a straightforward surgical procedure enhancing the rate of canine retraction significantly.

In silico study of cuspid' periodontal ligament damage under parafunctional and traumatic conditions of whole-mouth occlusions. A patient-specific evaluation

BACKGROUND AND OBJECTIVE

Although traumatic loading has been associated with periodontal ligament (PDL) damage and therefore with several oral disorders, the damage phenomena and the traumatic loads involved are still unclear. The complex composition and extremely thin size of the PDL make experimentation difficult, requiring computational studies that consider the macroscopic loading conditions, the microscopic composition and fine detailed geometry of the tissue. In this study, a new methodology to analyse the damage phenomena in the collagen network and the extracellular matrix of the PDL caused by parafunctional and traumatic occlusal forces was proposed.

METHODS

The entire human mandible and a portion thereof containing a full cuspid tooth were separately modelled using finite element analysis based on computed tomography and micro-computed tomography images, respectively. The first model was experimentally validated by occlusion analysis and subjected to the muscle loads produced during hard and soft chewing, traumatic cuspid occlusion, grinding, clenching, and simultaneous grinding and clenching. The occlusal forces computed by the first model were subsequently applied to the single tooth model to evaluate damage to the collagen network and the extracellular matrix of the PDL.

RESULTS

Early occlusal contact on the left cuspid tooth guided the mandible to the more occluded side (16.5% greater in the right side) and absorbed most of the lateral load. The intrusive occlusal loads on the posterior teeth were 0.77-13.3% greater than those on the cuspid. According to our findings, damage to the collagen network and the extracellular matrix of the PDL could occur in traumatic and grinding conditions, mainly due to fibre overstretching (>60%) and interstitial fluid overpressure (>4.7 kPa), respectively.

CONCLUSIONS

Our findings provide important biomechanical insights into the determination of damage mechanisms which are caused by mechanical loading and the key role of the porous-fibrous behaviour of the PDL in parafunctional and traumatic loading scenarios. Besides, the 3D loading conditions computed from occlusal contacts will help future studies in the design of new orthodontics appliances and encourage the application of computing methods in medical practice.

Cheek tooth erosion in male babirusa (genus Babyrousa)

The wear on the occlusal surfaces of male babirusa cheek teeth was evaluated in 53 skulls of Babyrousa babyrussa from Buru and the Sula Islands and 87 skulls of B. celebensis from Sulawesi, Indonesia. Based on the comparative lengths of their continually growing maxillary canine teeth, the skulls were divided into five 'age categories' (A-E). Numerical and symbolic codes representing tooth wear were applied to each pillar (cusp region) of the mandibular and maxillary permanent third and fourth premolar teeth, and the first, second and third permanent molar teeth. There was no significant difference between the tooth wear patters of skulls in groups A and B, or in groups C and D, and so these were amalgamated. There was close correspondence in wear patterns between each side of the mouth in both species and in each age group. The wear patterns of the mandibular and maxillary teeth, although not identical, were very similar, as were the wear patterns of both species. In group A+B for both species tooth wear was relatively slight, with the M1 teeth experiencing most relative wear. There was almost no wear of the M3 teeth. In group C+D substantial wear of upper and lower M1 was evident. In group E more widespread wear of the cheek teeth was seen, with increased severity of M1 tooth wear, yet there was comparatively much less M2 and M3 tooth wear. The pattern of cheek tooth wear of the Babyrousa spp. was different from that shown by Susscrofa. Differences in diet selection and processing were highlighted as potential contributing factors. The pattern of cheek tooth wear in male babirusa was not adequate for use to monitor their age.

Space conditions, palatal vault height, and tooth size in patients with and without palatally displaced canines: A prospective cohort study

OBJECTIVES:

To assess palatal vault height, tooth size, and dental arch dimensions in patients with unilateral and bilateral palatally displaced canines compared with a control group.

MATERIALS AND METHODS:

A sample of 66 patients (mean age: 11.5 ± 1.0 years) with 22 unilateral palatally displaced canines (UPDCs), 22 bilateral palatally displaced canines (BPDCs), and 22 controls (C) were consecutively recruited. All three groups had dental casts that were scanned digitally using the OrthoX three-dimensional model scanner. Tooth size, palatal vault height, dental arch width, dental arch depth, dental arch length, and dental arch space were measured by the same examiner using the GOM software. Remeasurements were made in 10 randomly identified patients.

RESULTS:

The palatal vault height was significantly lower in the BPDC group compared with controls. A significantly smaller mesial-distal crown width and, in general, more spacing in the maxilla were found in the UPDC and BPDC groups. No differences in arch length or arch width at the molar region were seen between the groups, while the arch length at the canine region was smaller in the UPDC and BPDC groups. However, this was observed in BPDC patients with both deciduous canines present and in most UPDC patients where the deciduous canine was present, compared with the control group, who had more permanent canines present.

CONCLUSIONS:

Patients with PDC had greater reduction in tooth size compared with the control group. The arch length and arch width were similar in patients with and without PDC.

Association between maxillary lateral incisors' root volume and palatally displaced canines: An instrumental variables approach to the guidance theory

OBJECTIVES:

To evaluate association and causation between maxillary lateral incisors' (MxI2) apical root volume (ARV) and palatally displaced canines (PDC).

MATERIALS AND METHODS:

In a retrospective cross-sectional study, computed tomography scans of 179 patients with unilateral PDC were analyzed. MxI2 root length and volume on the impaction and eruption side were measured. A mixed logit model was used to infer the association between ARV and PDC and an instrumental variables approach to interpret causality.

RESULTS:

MxI2 root length on the impaction side was shorter in 42%, equal in 33% and longer in 25% of the patients. ARV amounted for 13.5% of total root volume on the impaction and 14.9% on the eruption side. Reduced ARV was significantly associated with the impaction side ( P < .001). The causal effect of ARV on PDC in the instrumental variable approach amounted to less than half of the association in a standard noncausal approach.

CONCLUSIONS:

An association between PDC and reduced MxI2 root length and volume was confirmed. However, the lack of causality did not allow the researchers to draw a conclusion as to whether a reduced ARV is causing PDC or resulting from it; this should be considered in etiologic theories.

TACTICS OF THE TREATMENT OF TEETH TRANSPOSITION (CASE REPORTS)

Transposition of teeth - mutual exchange of the teeth position in the dental arch, it's a rare anomaly of the dentoalveolar apparatus. Most often in the transposition process the upper canines are involved in combination with the first premolars. Anomaly is mainly caused by an incorrect location of the teeth germs. Full correction is optimal in the treatment of transposition in terms of function and aesthetics, but in most cases, the movement of these teeth in their physiological position is impossible. Aim - to define and argue the tactics of the orthodontist in the treatment of patients with teeth transposition. The algorithm for curation of patients with teeth transposition consisted of several blocks: the establishment of etiologic factors, clinical and additional examination methods, planning and making treatment tactics, the stages of active treatment and management of the patient in the retention period. Among additional methods of examination were used: orthopantomography, 3D computer tomography, photometry, anthropometry. For a visual demonstration of orthodontic treatment, an curation algorithm of two patients with a teeth transposition was described. The choice of treatment options depended on the location and type of transposition (full or partial), the age of the patient, the condition of the periodontal tissue, the size of the teeth and their roots, the degree of tooth dislocation and root inclination, the type of occlusion, the bone thickness in the region of alveolar process, the level of cooperation between the patient and the doctor. Knowledge of the treatment tactics of patients with teeth transposition allows the orthodontist to normalize the individual teeth position, restore function and aesthetics in an optimal time. After our patient's treatment, positive esthetic, morphological and functional results were achieved.

Attitude of the Canine in Secondary Bone-Grafted and Nongrafted Patients with Cleft Lip and Palate

Objective

To investigate the eruption pattern of the cleft-side canine regarding its pre-eruption position relative to the cleft in bone-grafted (BG) and nongrafted (NonBG) patients with cleft lip and palate.

Methods

Fifty-three patients with cleft lip and palate (21 BG, 32 NonBG) were examined by panoramic radiography and posteroanterior cephalography taken before and after canine eruption. Subjects were categorized into BG, NonBG, and control groups. Canines at the pre-eruption stage were categorized as close to (group 1) or distant from (group 2) the cleft area. The canine angle and its change between the two stages were evaluated.

Results

No significant differences were noted between the initial canine angle of the BG and NonBG groups. Although canines in the BG group erupted without a significant change in angle, the canine angle increased significantly (p < .0001) in the NonBG and control groups. In group 1, a greater change in canine angle was noted in the NonBG (p < .05) and control (p < .01) groups than in the BG group. In group 2, no significant difference was noted among the three groups.

Conclusions

In BG patients, a canine located near the cleft appears to erupt at the same angle as it had before grafting. However, in NonBG patients, it erupts more vertically, guided by cortical bone. For canines distant from the cleft area, there is no significant difference in the change in angulation between NonBG and BG patients.

The Crown Size and Sexual Dimorphism of Permanent Teeth in Jordanian Cleft Lip and Palate Patients

Objective:

To provide a detailed description of crown size dimensions in the permanent dentition of Jordanian cleft lip and palate patients and to compare the findings with those of other populations.

Method:

The mesiodistal crown diameters of the permanent teeth of 47 patients with unilateral cleft lip and palate (UCLP), 25 patients with bilateral cleft lip and palate (BCLP), and 74 controls were measured.

Results:

The cleft group (UCLP and BCLP patients) generally demonstrated a smaller tooth size for both the maxillary and mandibular arches than did the control group. A sexual dimorphism pattern with males having larger teeth than females was observed for controls and UCLP patients. More males with BCLP had smaller teeth than did females. In the maxilla, the UCLP cleft-side teeth showed the largest percentage (4%) of sexual dimorphism, whereas the BCLP teeth achieved the highest percentage (3.4%) in the mandible. The UCLP cleft-side maxillary lateral incisors (13.2%) and BCLP mandibular canines (6%) displayed greater sexual dimorphism in crown size than did any other tooth class.

Conclusions:

Tooth size reduction occurred across all permanent tooth types and among early and late-forming teeth in cleft patients compared with the controls. This reduction was more pronounced in the maxillary incisor field. Males with UCLP and control males had larger teeth than did females, whereas a reversal of the normal dimorphism pattern was observed in patients with BCLP.

Peridental bone changes after orthodontic tooth movement with fixed appliances: A cone-beam computed tomographic study

OBJECTIVE

To quantify treatment-related changes in peridental bone height and thickness in orthodontic patients.

MATERIALS AND METHODS

Cone-beam computed tomographs (CBCTs) of 43 patients (24 female, 19 male; mean age: 25 years, 5 months) who underwent orthodontic treatment with multibracket appliances for at least 1 year were chosen for retrospective evaluation. Dehiscence depth and changes in bone width and tooth inclination were determined for 954 teeth.

RESULTS

There was a significant decrease in peridental bone height (dehiscence; -0.82 ± 1.47 mm) and bone thickness (-0.56 ± 0.7 and -0.69 ± 0.9 mm at 5 mm and 10 mm apical to the CEJ, respectively) during treatment (P < .001). A significantly greater dehiscence depth with increased vertical bone loss occurred in patients older than 30 years. In patients <30 years old, approximately 20% of the teeth showed defect depths >2 mm before treatment. In 90% of these patients, at least one tooth was affected. The maxillary canines and all mandibular teeth showed a higher risk for vestibular bone loss. Treatment changes in tooth inclination were correlated with horizontal bone loss.

CONCLUSIONS

Based on these results, it seems reasonable to recommend that peridental bone in orthodontic patients older than 30 be evaluated on a routine basis due to the risk of increased vertical bone loss. Ninety percent of patients younger than 30 showed reduced bone height (dehiscence) of the periodontium of at least one tooth.

[Diagnossis and treatment of complicated anterior teeth esthetic defects by combination of whole-process digital esthetic rehabilitation with periodontic surgery]

OBJECTIVE

To explore a new method of whole-process digital esthetic prosthodontic rehabilitation combined with periodontic surgery for complicated anterior teeth esthetic defects accompanied by soft tissue morphology, to provide an alternative choice for solving this problem under the guidance of three-dimensional (3D) printing digital dental model and surgical guide, thus completing periodontic surgery and digital esthetic rehabilitation of anterior teeth.

METHODS

In this study, 12 patients with complicated esthetic problems accompanied by soft tissue morphology in their anterior teeth were included. The dentition and facial images were obtained by intra-oral scanning and three-dimensional (3D) facial scanning and then calibrated. Two esthetic designs and prosthodontic outcome predictions were created by computer aided design /computer aided manufacturing (CAD/CAM) software combined with digital photography, including consideration of white esthetics and comprehensive consideration of pink-white esthetics. The predictive design of prostheses and the facial appearances of the two designs were evaluated by the patients. If the patients chose the design of comprehensive consideration of pink-white esthetics, they would choose whether they would receive periodontic surgery before esthetic rehabilitation. The dentition design cast of those who chose periodontic surgery would be 3D printed for the guide of periodontic surgery accordingly.

RESULTS

In light of the two digital designs based on intra-oral scanning, facing scanning and digital photography, the satisfaction rate of the patients was significantly higher for the comprehensive consideration of pink-white esthetic design (P<0.05) and more patients tended to choose priodontic surgery before esthetic rehabilitation. The 3D printed digital dental model and surgical guide provided significant instructions for periodontic surgery, and achieved success transfer from digital design to clinical application. The prostheses were fabricated by CAD/CAM, thus realizing the whole-process digital esthetic rehabilitation.

CONCLUSION

The new method for esthetic rehabilitation of complicated anterior teeth esthetic defects accompanied by soft tissue morphology, including patient-involved digital esthetic analysis, design, esthetic outcome prediction, 3D printing surgical guide for periodontic surgery and digital fabrication is a practical technology. This method is useful for improvement of clinical communication efficiency between doctor-patient, doctor-technician and doctors from different departments, and is conducive to multidisciplinary treatment of this complicated anterior teeth esthetic problem.

[Clinical evaluation of periodontal-orthodontic treatment in patients with aggressive periodontitis and malocclusion]

OBJECTIVE

To evaluate the clinical effect and safety of periodontal-orthodontic treatment in patients with aggressive periodontitis (AgP) and malocclusion.

METHODS

A retrospective analysis was conducted in 25 AgP patients, who had received periodontal-orthodontic treatment in Peking University School and Hospital of Stomatology. Clinical indexes, including probing depth (PD), bleeding index (BI) and percentage of sites with bleeding on probing (BOP%) were evaluated at three time points: Baseline (T0); active periodontal treatment finished and before orthodontic treatment (T1); and after orthodontic treatment (T2). Also changes of ratio of the residual alveolar bone height (RBH) and the occurrence of root resorption were evaluated by periapical radiographs.

RESULTS

(1) Compared with T0, all the clinical parameters including PD, BI, BOP% and percentage of sites with PD>3 mm were significantly improved (P<0.001). (2) Significant difference was observed in the average RBH between T0 (68.37%±15.60% and T2 (70.27%±14.23%). RBH in upper incisors [(58.79%±16.71% at T0, 65.54% (55.74%, 78.13%) at T2], upper canines [77.62% (66.06%, 87.17%) at T0, 79.57% (69.75%, 86.52%) at T2] and upper molars [74.30% (61.69%, 84.45%) at T0, 76.76% (68.12%, 85.09%) at T2] showed significant increase (P<0.05). (3) After orthodontic treatment, varying degrees of root resorption occurred in (23.94%±13.45%) of teeth per capita, among which the lower and upper incisors showed the highest incidence (68.48% and 65.31% in homogeneous teeth, respectively).

CONCLUSION

After active periodontal treatment, orthodontic treatment in AgP patients had not aggravated inflammation and alveolar bone resorption; root resorption occurred in two-thirds of incisors approximately.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

OBJECTIVE

The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth.

MATERIAL AND METHODS

Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05).

RESULTS

There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups.

CONCLUSIONS

Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.

Comparative evaluation of microleakage of a carbomer/fluoroapatite-enhanced glass-ionomer cement on primary teeth restorations

AIM

Carbomer cement represents a novel glass-ionomer which gradually mineralises into fluoroapatite. Purpose of this study was to evaluate microleakage around restorations in deciduous teeth made with composite resin, conventional glass-ionomer cement, resin-modified glass-ionomer cement and carbomer/fluoroapatite-enhanced glass-ionomer cement.

MATERIALS AND METHODS

A group of 40 primary upper canines, primary upper and lower molars was divided into 4 groups (n=10). Class I cavities were prepared by diamond cylindrical bur at high speed and were restored with a composite resin (Group 1), with a glass- ionomer cement (Group 2), with a resin-modified glass-ionomer cement (Group 3) and with a carbomer/fluoroapatite-enhanced glass- ionomer cement (Group 4). Hard tissue's bonding involved, in the case of composite resin a total etch bonding procedure, and in glass ionomers the use of their respective primers. Restorations were finished and polished. A 24-hour water storage was followed by thermocycling (1500 cycles, 5°C - 36°C - 55°C - 36°C with a dwell time of 15 seconds) and dye penetration test with immersion in 5% methylene blue for 24 hours. In order to assess the degree of microleakage longitudinal cuts were produced by means of a microtome at 0.5 mm and at 1 mm from the restoration margin, and photographs were taken with a stereomicroscope at 100X. Microleakage was classified according to the number of surfaces and the depth at which dye penetration was observed. Data were analysed with ANOVA and post-hoc analysis was performed with Bonferonni test (p<0.05).

RESULTS

Statistical analysis exhibited no significant statistical difference between Group 2 and Group 3 (p>0.05). Statistical difference was exhibited between Group 3 and Group 4 (p<0.01), with Group 4 exhibiting lower microleakage values. Group 1 exhibited the lowest mean microleakage values and statistical difference in comparison with all groups (p<0.001). Group 4 exhibited the lowest microleakage values among the cements.

CONCLUSION

Superior marginal integrity is achieved in restored primary teeth when composite resin is used. If the clinical case suggests the use of a glass-ionomer cement, carbomer/fluoroapatite-enhanced glass-ionomer cement is prefered in terms of microleakage.

Comparison of longitudinal changes in clinical periodontal parameters of canines and first molars treated with fixed orthodontic appliances

INTRODUCTION

Our objective was to learn the possible effects of fixed orthodontic therapy on the periodontium of the extraction sites adjacent to canines and first molars. This was a prospective cohort study.

METHODS

Sixty-two systemically healthy subjects were selected. The study was divided into the period of oral hygiene instructions and the period of active orthodontic treatment. Plaque index, gingival index, probing pocket depth, and clinical attachment loss were recorded for the canines and first molars at baseline, after 1 month of orthodontic therapy, and every 3 months until the completion of the orthodontic treatment.

RESULTS

There was a statistically significant increase in all clinical parameters (plaque index, gingival index, probing pocket depth, and attachment loss; P <0.05) on the first molars compared with the canines. Significant increases in attachment loss were noted in both the canines (baseline, 0.06 ± 0.01 mm; end of treatment, 0.17 ± 0.02 mm) and the molars (baseline, 0.07 ± 0.01 mm; end of treatment, 0.20 ± 0.02 mm).

CONCLUSIONS

Attachment loss cannot be explained solely by the effect of plaque or the banding of teeth. Other factors such as tooth extractions adjacent to the canines, tooth movement, and occlusal trauma may have contributing roles in the loss of periodontal support in adolescent patients.

Orthodontic Correction of a Base Narrow Mandibular Canine Tooth in a Cat

A 6-month-old cat was diagnosed with a lingually displaced mandibular canine tooth causing palatal trauma. This case report describes the correction and outcome for orthodontic movement of the left mandibular canine tooth.

A Guided, Conservative Approach for the Management of Localized Mandibular Anterior Tooth Wear

The successful management of the worn mandibular anterior dentition may present an awkward challenge to the dental operator. The purpose of this article is to describe a case report illustrating the use of a guided, three-dimensional protocol for the ultra-conservative and predictable restoration of the worn lower anterior dentition using direct resin composite. This technique utilizes information based on established biomechanical and occlusal principles to fabricate a diagnostic wax-up, which is duplicated in dental stone. This is used to prepare a vacuum-formed modified stent, assisting the clinician to place directly bonded resin composite restorations to restore the worn lower anterior dentition. The technique, described in 2012 and referred to as 'injection moulding' has the potential to offer optimal form, function and an aesthetic outcome in an efficient manner. CPD/Clinical Relevance: This article aims to describe an alternative technique to simplify the processes involved with restoration of worn lower anterior teeth.

[Failures regarding the treatment plan]

Who has never had a treatment failure? Who has never regretted launching into a treatment plan? And who has never vowed to avoid falling again into the same trap? All of us, of course. Which simply allowed us to fall into other traps once we'd pulled ourselves out of our previous failures. And to start with, do we believe that a successful outcome means achieving a molar and canine bilateral Class I, a normal overjet and overbite, and centered and coinciding midlines? So, does that make any other kind of treatment plan a recipe for failure? In more realistic mode, we should consider a treatment plan a failure when we are unable to achieve the objectives we set ourselves at the beginning of treatment, due to a lack of realism, or excessive optimism...

Frequency and distribution of teeth treated by single- and multiple- visit root canal treatment in a Nigerian population by differently skilled operators

BACKGROUND

Single visit root canal treatment (RCT) is being advocated around the world. This study profiles RCT in a Nigerian population and compares pattern of single versus multiple visit RCT to tooth type and skill level of the doctors.

METHOD

A retrospective study was carried out on RCT performed in one year by fresh graduates and postgraduate dentists. Records retrieved included patients' sex and age, tooth type, location in the jaw and whether single- or multiple-visit RCT was done.

RESULTS

Records of 705 teeth were reviewed, 54.6% belonged to females. Age range was 18-87 years, mean of 31.76 (± 12.31) years. Majority (70.1%) belonged to 20-39 years' age group. Most teeth were located in the maxilla (60.8%) and in posterior regions (73.6%). The most frequently root filled tooth was the mandibular first molar (20.7%) followed by maxillary central incisor (18.4%) then maxillary premolar (12.8%). However, all molars accounted for 47.3%, premolars 26.3% and incisors 25.0%. Canines (1.45%) were least frequently root-filled. Incisors (54.8%) were the teeth most frequently treated in single-visit followed by premolars (28.8%). Most frequently treated by multiple-visit were molars (51.0%). All doctors performed multiple-visit RCT in an approximately equal proportion but a significant percentage of single-visit RCT was carried out by senior doctors (71.2%).

CONCLUSION

The most frequently root filled teeth were mandibular first molars. Teeth most likely to be treated by single-visit RCT were incisors. Appropriate operator skill and experience is important in the decision to perform single-visit RCT. Single-visit RCT is advocated in the developing environment.

Amelogenesis Imperfecta with Coronal Resorption: Report of Three Cases

Intracoronal resorption of the permanent dentition in cases of amelogenesis imperfecta (AI) is a rare finding which poses an added complication to the already complex management of this condition. This paper presents three cases of AI associated with delayed eruption of permanent teeth in which asymptomatic intracoronal resorption occurred. CPD/Clinical Relevance: This paper highlights the fact that teeth affected with amelogenesis imperfecta may undergo asymptomatic intracoronal resorption which is only identifiable radiographically.

The Ethics of Interproximal Reduction

Interproximal reduction (IPR) has become particularly popular with the use of removable aligners. Clinical and ethical factors concerning the use of interproximal reduction to facilitate orthodontic alignment are discussed. CPD/Clinical Relevance: An understanding of the aetiological factors of a malocclusion is essential to enable full discussion of the risks and benefits, or the alternatives to IPR.

The Influence of Crown Height to Diameter Ratio on the Force to Fracture of Canine Teeth in Dogs

Previous work suggests that the tooth height to diameter ratio (H/D) may have an influence on the fracture resistance of dog canine teeth. Thus, it can be hypothesized that canine teeth with distal abrasion or teeth already requiring pulpal manipulation may benefit from a reduction in height and that an ideal H/D exists that balances tooth fracture resistance and tooth function. Therefore, a study was performed to investigate the influence of H/D on force to fracture and probability of fracture of canine teeth in dogs. Thirty extracted canine teeth from laboratory Beagle dogs were standardized by hard tissue volume and evenly distributed among three groups; unaltered H/D (group A), 10% reduction in H/D (group B), and 20% reduction in H/D (group C). The teeth were potted in clear autopolymerizing orthodontic acrylic and then secured within a universal materials testing machine. A displacement was applied at a speed of 1-mm/min to the distoocclusal line angle at an angle of 45 degrees to the long axis of the crown. The maximum measured force at the time of fracture represented the maximum force to fracture. A linear regression model showed a significant inverse relationship between H/D and force to fracture (p = 0.043; 95% CI-55.2 to -0.09). A margin of safety (MoS) analysis was performed to determine the probability of fracture by comparing normal force distributions of the measured force at fracture to that reported in a previous study, representative of normal biting-pulling loads on canine teeth. When 100% of the load was applied to a single unaltered canine tooth the probability of fracture was 36.7%. Decreases in H/D of 10% and 20% resulted in a decreased probability of fracture by 24.1% and 60.4%, respectively. A paired MoS analysis was conducted wherein the applied loads were distributed across 2 maxillary canine teeth according to their relative heights. Within the pair, a 20% decrease in H/D decreased the probability of fracture of that tooth by 86.5%, but increased the probability of fracture of the unaltered contralateral canine tooth by 54.4%. The findings of this study support the hypothesis that teeth with a lower H/D are more resistant to fracture. However, given the potential impact of crown reduction of a single canine tooth on the load redistribution to the remaining unaltered canine teeth, further investigation is needed to determine what H/D would be ideal. In addition, future studies could elucidate in which clinical scenarios the concept of H/D reduction could be implemented. The results of this study may have implications on the successful long-term management of traumatized canine teeth in dogs.

Etiology of maxillary canine impaction: a review

This article is a review that enumerates the causes of impaction of the maxillary permanent canines, including hard tissue obstructions, soft tissue lesions, and anomalies of neighboring teeth, and discusses the much-argued relationship between environmental and genetic factors. These phenomena have been shown in many investigations to accompany the diagnosis of canine impaction and have been presented as unrelated anomalous features, each of which is etiologically construed as genetic, including the aberrant canine itself. While in general the influence of genetics pervades the wider picture, a guidance theory proposes an alternative etiologic line of reasoning and interpretation of these studies, in which the same genetically determined anomalous features provide an abnormal milieu in which the canine is reared and from which it is guided in its misdirected and often abortive path of eruption.

Surgically Assisted Orthodontics: Use of Piezocision in a Case of Oligodontia to Accelerate the Rate of Tooth Movement

Conventionally the use of surgical assisted tooth movement is to hasten orthodontic tooth movement. In this article, a case of 13 year-old male with oligodontia has been described in whom piezocision has been used to improve bone turnover and remodeling in long standing edentulous spaces which have less medullary bone and more cortical bone.

Treatment of Bi-maxillary Protrusion with Impacted Maxillary and Mandibular Canines: Case Report

Bi-maxillary protrusion in adolescent patients has traditionally been treated by extraction of the four first premolars and retraction ofthe anterior teeth. The ectopic eruption of the maxiIlary permanent canines is a frequently encountered clinical problem. Orthodontic treatment of the impacted teeth remains a challenge for clinicians. If it is associated with other dental and skeletalproblems, there will be further complications to the treatment plan. In such cases, if we extract canines, then problems with this approach are restricted to anatomical and functional limitations ofpremolars substitution of canines. Here, we are presenting a case report of bi-maxillary dento-alveolar protrusion with the impacted maxillary and mandibular left canines and its management.

Is the value of oral health related to culture and environment, or function and aesthetics?

OBJECTIVE

To examine the disutility of tooth loss. It compared how people value their teeth in two countries which are culturally similar in order to explore the effect of culture on self-perceptions of oral health.

BASIC RESEARCH DESIGN

Cross sectional study.

PARTICIPANTS

Participants were recruited from subjects attending two hospitals in Turkey and in Iran.

INTERVENTIONS

Nineteen descriptions of mouths with varying degrees and types of tooth loss were presented to the participants. They were shown mouth models of partially edentate dentitions and the teeth missing were explained in relation to the participants own mouth. The participants were specifically asked to consider the role their teeth played in function (chewing), communication (speech) and aesthetics (looks) along with "all the other things that make your mouth important".

MAIN OUTCOME MEASURES

The participants were asked to indicate on a visual analogue scale how they would value the health of their mouth if they lost the tooth/teeth described and the resultant space was left unrestored.

RESULTS

Overall 152 subjects participated, 78 in Turkey and 74 in Iran with 83 being female and 69 male. Their mean age was 29.5 years (SD 9.3), 62.5% had experienced tooth loss and 37.5% had complete (or completely restored) dentitions. Although there were no differences between the two countries in the degree of utility people attached to anterior teeth, Turkish participants attached significantly more disutility than Iranians to the loss of premolar and molar teeth (p < 0.003).

CONCLUSION

Country of origin had an influence on the value placed on certain parts of the dentition and this effect is independent of the number of missing teeth, gender and age. This implies that attitudes to oral health are influenced by prevalent cultural attitudes more than by function.

Mandibular changes secondary to serial extractions compared with late premolar extractions and controls

INTRODUCTION

Variations in treatment times for serial extraction and late premolar extraction patients may be due to differences in the time needed to flatten the occlusal curves. In this study, we compared tooth tipping and occlusal curves in patients treated by serial extractions or late premolar extractions with untreated controls.

METHODS

Mandibular dental casts and cephalometric radiographs were collected from 90 subjects (30 Class I control subjects, 30 patients with serial extractions, and 30 with late premolar extractions) at 3 time points: T0, baseline for the controls and serial extraction patients; T1, after natural drift and preorthodontics for the controls and the serial extraction patients, and pretreatment for the late premolar extraction patients; and T2, after comprehensive orthodontic treatment for the serial extraction and the late premolar extraction groups. The long axes of the central incisor, canine, and first molar to the palatal plane were measured on digitized headfilms to determine the direction and the amount of tipping between the time points. Three occlusal curves were measured by sphere fitting cusp-tip landmarks on digitized mandibular casts.

RESULTS

From T0 to T1, incisors and canines in the patients with serial extractions tipped distally. Molars at T1 in the patients with serial extractions were tipped forward more than in the late premolar extraction patients and the controls. From T1 to T2, canines and molars in the patients with serial extractions were uprighted.

CONCLUSIONS

Serial extractions produce steeper occlusal curves and distal tipping of the incisors and canines after drift (T1). Posttreatment (T2) occlusal curves in the patients with serial extractions are steeper than in the late premolar extraction patients and controls (except for the curve of Spee). After the serial extractions, orthodontic treatment included incisor and canine proclination, with molar uprighting and occlusal curve flattening.

An Update on Crown Lengthening. Part 2: Increasing Clinical Crown Height to Facilitate Predictable Restorations

This is the second paper in this two-part series. Paper one provided an overview of managing gingival tissue excess and paper two will focus on increasing clinical crown height to facilitate restorative treatment. Crown lengthening is a surgical procedure aimed at the removal of gingival tissue with or without adjunctive bone removal. The different types of procedure undertaken will be discussed over the two papers. In order to provide predictable restorations, care must be taken to ensure the integrity of the margins. If this is not taken into account it can lead to an impingement on the biologic width, which may in turn lead to chronic inflammation resulting in recession or the development of periodontal problems which can be hard to manage. Clinical Relevance: This paper aims to reinforce the need for thorough diagnosis and treatment planning and provides an overview of the various procedures that can be undertaken.

Functional crown lengthening surgery in the aesthetic zone; periodontic and prosthodontic considerations

Crown lengthening surgery aims to increase the amount of supragingival tooth tissue by resection of the soft and/or hard tissues to enable otherwise unrestorable teeth to be restored by increasing the retention and resistance forms of the teeth. Restoration of the worn dentition may require significant prosthodontic knowledge and skill. A prosthodontist should be involved from the beginning of the management of the patient. A number of key stages should be considered for correct management. Although the periodontist may guide the prosthodontist with regards to what may or may not be possible surgically, the overall treatment plan should be prosthodontically driven. Clinical Relevance: Toothwear of the anterior dentition provides a unique challenge to restore not only function but also to manage the aesthetic demands of the patient. To ensure that the correct outcome is reached, clinicians should be familiar with the normal anatomical proportions and relationships to enable planning and treatment to take place.

Rapid maxillary expansion in early-mixed dentition: effectiveness of increasing arch dimension with anchorage on deciduous teeth

AIM

To assess the effectiveness of a Haas expander anchored to deciduous teeth in changing dental arch dimension and improving crowding and to evaluate stability of changes until permanent dentition.

STUDY DESIGN

closed cohort retrospective and case-control study. Eighteen patients undergoing early treatment for lateral crossbite (mean age 7.6 yrs; SD 1.0) at two practices located in La Spezia and Massa (Italy) were analysed. The treated group was compared with 72 control subjects divided into: 32 untreated adolescents with and without lateral crossbite and the same canine dental class as treated patients before expansion (Class II Division 2), 18 adults and 18 adolescents with dental Class I. All groups were matched for gender (ratio males:females, 8:10). The dental casts images of treated patients were digitally measured before and after treatment, and in permanent dentition. Patients at the last follow-up were compared with control subjects.

RESULTS

In treated patients the increase in intermolar width and the improvement in anterior crowding were significant and stable until adolescence. Untreated adolescents with lateral crossbite showed the narrowest transversal widths and the highest irregularity. No difference was found among treated patients, adolescents without lateral crossbite, and adolescents and adults with a normal occlusion.

CONCLUSIONS

The Haas expander anchored on deciduous teeth is effective in improving dental arch constriction and crowding in patients treated for lateral crossbite. The result is stable until permanent dentition. In absence of treatment, constriction of dental arch may persist, with a higher level of irregularity.

[Maxillary canine impaction increases root resorption risk of adjacent teeth: A problem of physical proximity]

INTRODUCTION

Our objectives were to investigate the prevalence, resorption location and extent, and potential risk factors for impacted canine-associated root resorption (ICARR) in Chinese patients, who, unlike white patients, have predominantly buccal maxillary canine impactions.

METHODS

Pretreatment cone-beam computed tomography scans of 170 Chinese subjects (ages, 12-30 years; mean, 14.5 years) with impacted maxillary canines (101 buccal and 69 palatal impactions) and 170 age- and sex-matched subjects without impactions were used. All cone-beam computed tomography records were evaluated in software programs by 1 rater. The prevalence, location, and extent of ICARR at the maxillary lateral incisor, central incisor, and first premolar were analyzed. To identify risk factors for ICARR, the subjects with impacted canine were divided into 2 groups (with and without root resorption). Measurements of 10 variables were individually compared between the groups and then tested together by using binary logistic regressions for each tooth.

RESULTS

Compared with the control subjects and the side of nonimpaction, root resorption was significantly more prevalent in the canine-impaction subjects and the side of impaction (P\0.01), with overall prevalence rates of 27%, 18% and 10% at the maxillary lateral incisor, the central incisor, and the first premolar, respectively. Predominantly affecting the apical third of all teeth, ICARR, if present, reached the pulp of the maxillary lateral incisor, the central incisor, and the first premolar at rates of 36%, 57%, and 0%, respectively. Individually, variables reflecting the proximity to the impacted maxillary canine had different measurements (P\0.05) between the impaction sites (maxillary quadrants) with and without root resorption for each tooth, whereas the canine development stage factor was only significant for the maxillary central and lateral incisors. No significant difference of ICARR prevalence was found between subjects with buccal and palatal impactions. Combined, the contact relationship was the dominant predictor for ICARR at all teeth, with "in contact" (\1 mm separation) having the largest and most significant increase of root resorption likelihood compared with "out of contact" ($1 mm separation); odds ratios were 9.9, 3.7 and 5.9 for the maxillary lateral incisor, the central incisor, and the first premolar, respectively.

CONCLUSIONS

Maxillary canine impaction increases the risk of root resorption at adjacent teeth (incisors and first premolars). Physical proximity (\1 mm) between the impacted canine and an adjacent root is the most important predictor for root resorption, and this characteristic is largely similar in Chinese patients to that in white people.

Shape variation and covariation of upper and lower dental arches of an orthodontic population

OBJECTIVES

This study aimed to quantify the patterns of shape variability and the extent and patterns of shape covariation between the upper and lower dental arch in an orthodontic population.

METHODS

Dental casts of 133 white subjects (61 males, 72 females; ages 10.6-26.6) were scanned and digitized in three dimensions. Landmarks were placed on the incisal margins and on the cusps of canines, premolars, and molars. Geometric morphometric methods were applied (Procrustes superimposition and principal component analysis). Sexual dimorphism and allometry were evaluated with permutation tests and age-size and age-shape correlations were computed. Two-block partial least squares analysis was used to assess covariation of shape.

RESULTS

The first four principal components represented shape patterns that are often encountered and recognized in clinical practice, accounting for 6-31 per cent of total variance. No shape sexual dimorphism was found, nevertheless, there was statistically significant size difference between males and females. Allometry was statistically significant, but low (upper: R(2) = 0.0528, P < 0.000, lower: R (2) = 0.0587, P < 0.000). Age and shape were weakly correlated (upper: R(2) = 0.0370, P = 0.0001, lower: R (2) = 0.0587, P = 0.0046). Upper and lower arches covaried significantly (RV coefficient: 33 per cent). The main pattern of covariation between the dental arches was arch width (80 per cent of total covariance); the second component related the maxillary canine vertical position to the mandibular canine labiolingual position (11 per cent of total covariance).

LIMITATIONS

Results may not be applicable to the general population. Age range was wide and age-related findings are limited by the cross-sectional design. Aetiology of malocclusion was also not considered.

CONCLUSIONS

Covariation patterns showed that the dental arches were integrated in width and depth. Integration in the vertical dimension was weak, mainly restricted to maxillary canine position.

The 'slingshot' technique to align palatally impacted canines with elastomeric chain

Orthodontic alignment of palatally ectopic maxillary canines can be challenging. Treatment is usually prolonged and further complicated by the need for surgical exposure. Several methods are commonly used and have been described in the literature. This article presents two cases to describe a relatively unknown yet effective technique using the 'slingshot' method. This method is operator friendly and easily tolerated by patients.

Restoring primary anterior teeth: updated for 2014

The purpose of this paper was to review the current literature associated with the techniques and materials for the restoration of primary anterior teeth and make clinical recommendations based upon the available literature. A variety of esthetic restorative materials are available to utilize for restoring primary incisors. Awareness of the specific strengths, weakness, and properties of each material can enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and crowns that are luted onto the tooth and are either some type of stainless steel or zirconia crown. There is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. Operator preferences, esthetic demands by parents, the child's behavior, the amount of tooth structure remaining, and moisture and hemorrhage control are all variables that affect the decision and ultimate outcome of whatever restorative solution is chosen.

A statistical modeling approach to computer-aided quantification of dental biofilm

Biofilm is a formation of microbial material on tooth substrata. Several methods to quantify dental biofilm coverage have recently been reported in the literature, but at best they provide a semiautomated approach to quantification with significant input from a human grader that comes with the grader's bias of what is foreground, background, biofilm, and tooth. Additionally,human assessment indices limit the resolution of the quantification scale; most commercial scales use five levels of quantification for biofilm coverage (0%, 25%, 50%, 75%, and 100%). On the other hand, current state-of-the-art techniques in automatic plaque quantification fail to make their way into practical applications owing to their inability to incorporate human input to handle misclassifications. This paper proposes a new interactive method for biofilm quantification in Quantitative light-induced fluorescence(QLF) images of canine teeth that is independent of the perceptual bias of the grader. The method partitions a QLF image into segments of uniform texture and intensity called superpixels; every superpixel is statistically modeled as a realization of a single 2-D Gaussian Markov random field (GMRF) whose parameters are estimated; the superpixel is then assigned to one of three classes (background, biofilm, tooth substratum) based on the training set of data. The quantification results show a high degree of consistency and precision. At the same time, the proposed method gives pathologists full control to postprocess the automatic quantification by flipping misclassified superpixels to a different state (background,tooth, biofilm) with a single click, providing greater usability than simply marking the boundaries of biofilm and tooth as done by current state-of-the-art methods.