Dental Dam Isolation for Crown Removal, Atraumatic Tooth Extraction, Immediate Implant Placement, and Restoration Cementation: A Case Study.

OBJECTIVES: This case report describes the clinical protocols for the removal of crowns, tooth extraction, immediate implant placement, and cementation of new crowns, all performed under total or partial isolation with a dental dam. CLINICAL CONSIDERATIONS: The patient's chief complaint was dissatisfaction with her smile. Radiographic and clinical evaluations led to the recommendation to replace the porcelain-fused-to-metal crowns on the maxillary central and lateral incisors with all-ceramic crowns. Considering the patient's wide smile, ceramic veneer restorations were also recommended for the maxillary canines and first premolars. An immediate implant placement was advised to replace the fractured maxillary right central incisor. CONCLUSIONS: Well-planned dental care including crown removal, tooth extraction, immediate implant placement, and cementation of new restorations can be successfully executed under isolation using a dental dam. The isolation improves access, visibility, and hygiene by preventing cross-contamination during the cementation procedure. The final outcome fulfilled the patient's esthetic demands.

Investigation of the association between COX-2 polymorphisms and external apical root resorption in orthodontically treated patients.

OBJECTIVE: To evaluate the association between single nucleotide polymorphisms (SNPs) in cyclooxygenase-2 (COX-2) and external apical root resorption (EARR) after orthodontic treatment. MATERIALS AND METHODS: This study analyzed the orthodontic records of patients from Regensburg University Hospital and two collaborating private practices. EARR was analyzed in the maxillary central incisors and first mandibular molars using pre- and post-treatment cephalometric and panoramic radiographs, respectively. Genomic DNA was obtained from salivary oral cells. Two SNPs in COX-2, rs5275 (3 prime untranslated region variant) and rs689466 (upstream transcript variant, downstream transcript variant), were genotyped using real-time Polymerase chain reaction (PCR). The linear regression models were fitted to assess the effects of the evaluated SNPs at a significance level of 5%. RESULTS: A total of 143 biologically unrelated patients (mean age: 13.5 ± 4.5 years) were included in the study. The F-test showed that only the regression for EARR in the mandibular molars in the dominant model for rs5275 G allele had a good fit (F = 3.50, P = 0.034). The model showed that individuals carrying at least one G allele for rs5275 had a 17% increase in EARR in the molars compared to common AA homozygotes (exp(B) = 1.17; 95% CI: 1.04, 1.32; P = 0.010). Although an effect of the G allele (rs5275) was detected, this effect did not explain much of the variability in EARR (adjusted R2 = 0.04). CONCLUSION: The results suggested that patients carrying the polymorphic form of the rs5275 were more likely to have EARR in the mandibular molars; therefore, COX-2 could have an effect on EARR. CLINICAL RELEVANCE: The knowledge of the genetic background concerning EARR after orthodontic treatment would aid in clinical practice to screen for associated genetic factors and potentially aid its prevention and management, considering that patients' genetic profiles would soon be available.

Comparative finite element analyses of stress exerted on the dentin by intraradicular posts.

The amount of residual dentin thickness and tooth position in the dental arch is crucial to determine whether an intraradicular post should be used. This study aimed to compare stress distribution on the root dentin of an endodontically treated tooth rehabilitated with CAD/CAM milled glass fiber posts (MP), cast metal posts (CMP), or prefabricated posts (PP) with or without ferrule support, using the finite element method. MATERIALS AND METHODS: A human upper central incisor was selected, scanned, and treated endodontically. The canal was then prepared for post-placement and scanned again for the fabrication of digital posts. The geometries of MP and CMP were based on the measurements made by digital scanning of the root canal. In contrast, the geometry of PP was determined by technical drawings provided by the manufacturer, taking into account the post-space preparation and the cement. Six digital models were established: MP1 with ferrule support, MP2 without ferrule support; CMP1 with ferrule support, CMP2 without ferrule support; PP1 with ferrule support, and PP2 without ferrule support. The simulation was performed using the finite element method. RESULTS: Oblique forces were identified as more relevant to the metallic element compared to vertical forces. The presence of a ferrule was considered a protective factor for the remaining tooth structure. When the ferrule was absent, stresses were more evenly distributed in MP compared to CMP and PP. Posts with a higher modulus of elasticity were associated with higher and unequal stresses in the root dentin, which could predispose the tooth to fractures. CONCLUSIONS: As for the restoration set as a whole, it can be concluded that stress distribution on the root dentin was more evenly distributed on the milled post than on the other posts when a ferrule was absent, and the oblique forces were more detrimental to the tooth structure than vertical forces and that ferrule support was a protective factor for the remaining tooth structure. CLINICAL SIGNIFICANCE: The results of the study provide valuable information on how different types of intraradicular posts and the presence of a ferrule affect the stress distribution in dentin. In the absence of a ferrule, milled and customized computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber posts can exhibit better fracture resistance and adhesion strength than prefabricated fiberglass posts and metal posts.

Incisors inclination in relation to lip parameters: a CBCT study.

INTRODUCTION: With the introduction of Cone Beam Computed Tomography (CBCT) in dentistry, precise measurements are now attainable. OBJECTIVE: This study seeks to explore the correlation between incisors inclination and various lip parameters utilizing CBCT technology. Moreover, it aims to assess whether specific incisors inclinations significantly influence lip thickness, length, and position. MATERIAL AND METHODS: This was a retrospective observational study of available records of orthodontic patients (n=84) aged between 11 and 17.5 years old with pre- and post-treatment CBCT imaging. The 3D Slicer software was used to assess lip parameters and incisors inclinations while adhering to standard CBCT imaging methods. Statistical analysis was conducted to find associations between incisors inclination and lip parameters. RESULTS: Within certain limits of incisor inclination, lip parameters showed minimal impact. Changes in upper incisor inclination within an average of 5° did not significantly correlate with upper lip parameters. Similarly, changes in lower incisor inclination within an average of 5.6° had no significant effect on lower lip parameters. However, inclination changes of tooth #21 within 5.4° significantly affected upper lip length within 0.35mm. CONCLUSIONS: Lip parameters remained unaffected with specific ranges of incisor inclinations, except for a slight effect on upper lip length with changes in inclination of tooth #21. Clinicians can consider the specific ranges of incisors inclination during treatment planning, especially for patients concerned about lip appearance.

Vertical root fractures and cracked teeth: post-endodontic root dentinal status through micro-CT assessment after ex vivo fiber post removal.

OBJECTIVES: This study aimed to investigate cracked teeth and vertical root fracture observable on micro-CT images of extracted roots of mandibular incisors, after fiber post removal. MATERIALS AND METHODS: Thirty mandibular incisors were selected with any degree of slight incisal wear inspected with the aid of a stereomicroscope under 12x magnification, in order to have a group of young adult specimens according to the criteria of Hugoson et al. A sample of twelve mandibular incisors were selected, aged between 20 and 30 years old, with similar dentine volume and thickness. The specimens were scanned in a micro-computed tomography (micro-CT) device and submitted to root canal shaping, root canal filling, post space preparation, post placement and post removal. RESULTS: From a total of six experimental endodontic timepoints until post removal of 12 mandibular incisors, 64,800 cross-sectional images were analyzed and no vertical root fracture (VRF) or cracked tooth were detected. CONCLUSIONS: Micro-CT assessment after ex vivo fiber post removal did not detect vertical root fracture or cracked tooth formation in the root canal walls of mandibular incisors. CLINICAL RELEVANCE: This study highlighted that fiber post removal per se was not able to propagate VRF or cracked tooth formation or promoted any interruption of the integrity of human root dentin.

Designing mouthwash formulations with innovative molecular components to control initial dental erosion in vivo.

OBJECTIVE: This study aimed to examine and compare the efficacy of mouthwashes containing different proteins and peptide on the prevention of enamel erosion in vivo, as well as to evaluate the participants' satisfaction with the formulations. METHODS: Twelve participants were selected and underwent five cross-over mouthwash phases: Water (control); 0.1 mg/mL CaneCPI-5; 0.5 mg/mL MaquiCPI-3; 0.1 mg/mL CsinCPI-2; and 0.037 mg/mL Stn15pSpS. After prophylaxis, the participants rinsed (1 min), followed by the acquired enamel pellicle (AEP) formation (2 h). An erosive challenge was made (biopsy, citric acid 1%, 15s) on the buccal surface of the central maxillary incisors. The Relative Surface Reflection Intensity (%SRI) was assessed and analyzed by ANOVA/Tukey's tests. The calcium release in acid was measured by the Arsenazo method and verified by Kruskal-Wallis/Dunn's tests. The Spearman's correlation was used between analyses. A questionnaire evaluated the satisfaction of participants. RESULTS: For both analyses, the results showed that mouthwashes containing the proteins or peptide were significantly more effective in preventing enamel erosion compared to deionized water, with no significant differences among the active ingredients (p < 0.05). Also, there was a significant negative correlation between %SRI and calcium released (r=-0.5754). The questionnaire revealed that the volunteers were satisfied with the taste of the products. In addition, the experimental procedures were well tolerable, and no side effects were reported. CONCLUSION: All mouthwashes containing proteins or peptide were acceptable and effective in protecting enamel against initial dental erosion in vivo. CLINICAL SIGNIFICANCE: This study highlights the potential of these pioneer organic components for the development of mouthwashes designed for people with risk of erosive tooth wear.

Radiographic characteristics and chronological patterns of transient apical breakdown (TAB) in luxated permanent teeth: A retrospective observational study.

AIM: To describe radiographic features, clinical signs and symptoms, and chronological patterns of post-traumatic transient apical breakdown (TAB) in luxated permanent teeth. METHODOLOGY: Records from 56 patients treated at the Dental Trauma Clinic of the School of Dentistry of the Federal University of Minas Gerais from 1993 to 2024 were accessed to collect demographic, clinical, and imaging features of 89 teeth that presented with radiographic signs of TAB after traumatic dental injury (TDI). Kaplan-Meier curves were built to illustrate the time elapsed between trauma until TAB onset and resolution for the whole sample and for each one of the TAB patterns. A Cox regression was used to explore the effect of clinical covariates in both events. RESULTS: Patients' mean age at the time of trauma was 17.7 ± 6.6 years (range 9.1 to 39.7 years), with most being male (59.6%). All included teeth were mature at the time of trauma (Moorrees stage 6). Upper central incisors (66.3%) were predominant and mostly suffered extrusions (40.4%) or lateral luxations (32.6%). TAB was observed as an expansion of the periodontal ligament associated with a "V-shaped" widening of the apical foramen together with apical root resorption in 45 teeth (50.6%). Expansion of the periodontal ligament associated with "V-shaped widening of the apical foramen only was observed in 32 teeth (36%), and 12 teeth (13.5%) showed expansion of the periodontal ligament associated with apical root resorption only. The overall median time for TAB onset was 3.2 months (range, 26 days to 8 months), being significantly lower for pattern 2 (1.8 months) when compared to TAB pattern 1 and 3 (3.4, and 3.9 months) respectively (Logrank test p values < 0.001 for both comparisons). The overall median time for TAB regression was 9.1 months (range, 4.8 to 34.8 months) after trauma. Again, TAB pattern 2 presented lower periods when compared to TAB pattern 1 and 3 (Logrank test p values < 0.001 and 0.013, respectively). Color changes were not frequent neither at the time of TAB onset nor at the time of TAB resolution. However, while most teeth (53.3%) did not respond to pulp sensibility tests at the time of TAB onset, this proportion decreased to 17.6% by the time of TAB resolution. CONCLUSION: TAB was mainly diagnosed within four months after luxation of mature teeth, most of them being resolved within the 1-year of follow-up. The most frequent TAB pattern was an expansion of the PDL associated with a "V-shaped" widening of the apical foramen together with external apical root resorption. CLINICAL RELEVANCE: These findings represent an important contribution for treatment decision-making during the follow-up of luxated permanent teeth.

MMP-9 expression in rat pup incisor teeth is not altered by maternal hypertension or maternal atenolol treatment during pregnancy and lactation.

Hypertension alters tooth formation and Atenolol reduces the blood pressure of spontaneously hypertensive rats (SHR) during pregnancy and lactation, and as demonstrated before, increases the microhardness of the SHR offspring's teeth. MMP-9 is overexpressed in different tissues of hypertensive animals and treatment of hypertension substances can reverse this alteration. We hypothesize hypertension alters the expression of MMP-9 in dental structures of SHR offspring and that treating female SHR with atenolol prevents this alteration. This study aimed to evaluate the expression of matrix metalloproteinase (MMP-9) in incisor teeth (IT) in male offspring of SHR (30 days old) treated or untreated with Atenolol during pregnancy and lactation. MMP-9 expression was evaluated in ameloblasts (AM), enamel matrix (EM), odontoblasts (OD), and predentin (PD) of IT through immunohistochemical reactions (immunoperoxidase). Data were analyzed by Shapiro-Wilk and Kruskal-Wallis (p < 0.05), with Dunn post-test. Histological differences were not observed between IT tissues of SHR and normotensive Wistar rats. For the first time, our data showed that MMP-9 expression in specific dental structures is not altered in SHR. Atenolol treatment increased MMP-9 immunostaining in EM of Wistar rat, however, Atenolol did not alter MMP-9 in the IT tissues of SHR. Our results demonstrated that MMP-9 expression in dental tissues is not affected by hypertension or atenolol treatment in dental tissues. If confirmed in humans, the results obtained in this study will corroborate the suggestion that MMP-9 is not a viable therapeutic target for the treatment of dental alterations associated with maternal hypertension.

Association between molar incisor hypomineralisation and tooth agenesis: a cross-sectional study in Brazilian children and adolescents.

PURPOSE: The aim of the present was to assess the association between MIH and tooth agenesis (TA) in orthodontic patients from the Federal University of Rio Grande do Norte, Natal, Brazil. METHODS: A cross-sectional study was performed to evaluate the presence of MIH and TA in a sample of 371 pretreatment orthodontic records from patients aged 9-18 years. Statistical analyses were performed using the Chi-square and Fisher's exact tests, and logistic regressions. RESULTS: There was a statistically significant association between the prevalence of tooth agenesis and MIH. A higher percentage of third molar agenesis, maxillary premolar agenesis, and mandibular second premolar agenesis was observed among children with MIH-affected teeth. Patients with MIH had a 2.43 times greater chance of third molar agenesis, and a 5.88 times higher likelihood of mandibular premolar agenesis. CONCLUSION: There is a weak association between MIH and TA. Furthermore, the presence of hypomineralised molars increases the risk of tooth agenesis.

Hydrogen Peroxide in the Pulp Chamber and Color Change in Maxillary Anterior Teeth After In-Office Bleaching.

While the literature has noted variations in hydrogen peroxide (HP) permeability, and consequently, tooth sensitivity among different types of anterior teeth, there is a scarcity of research on this specific topic. This study evaluated HP permeability and color change (CC) in different groups of human maxillary anterior teeth (canines, lateral incisors, and central incisors) after in-office bleaching with HP at 35%. Thirty teeth maxillary anterior (n=10) were bleached with HP at 35% gel in one session of three 15-minutes applications. Buccal thickness (mm) was measured from images obtained using cone beam computed tomography. The concentration of HP (µg/mL) that reached the pulp chamber was assessed using UV-Vis spectrophotometry. CC (WID, ∆Eab, and ∆E00) was evaluated before and after bleaching with a digital spectrophotometer. One-way ANOVA and Tukey's test were applied to statistically evaluate the data for buccal thickness, HP permeability, and CC (α=0.05). Comparison between thickness and HP permeability was performed using Pearson's correlation. Thicker teeth, such as canines, had lower HP amounts inside the pulp chamber compared to central and lateral incisors. Despite the significant effect of buccal thickness on HP permeability (p<0.05), no correlation was found between the two factors. CC was similar across tooth types (p>0.05). The difference in buccal thickness among the superior anterior teeth does not interfere with CC. However, a thinner buccal wall thickness is associated with greater HP permeability detected in the pulp after in-office bleaching.

3D Printed Dual Reduction Guide: A Feasible Alternative for Conservative Gingivectomy and Minimally Invasive Preparation for Ceramic Veneers.

OBJECTIVES: This case report describes a digital workflow for designing and 3D printing a guide with the dual purpose of gingivectomy and tooth preparation in the esthetic zone, to be followed by cementation of ceramic veneers under rubber dam isolation. CLINICAL CONSIDERATIONS: The patient's primary concern was to improve her smile. After clinical evaluation, our recommendation was for a minimal gingivectomy to match the gingival zenith for both central incisors, to be followed by ceramic laminate veneers. A digitally designed and 3D printed guide was used for gingivectomy and tooth preparation for the ceramic veneers. Ceramic veneers were cemented under rubber dam isolation to maximize bonding properties. CONCLUSIONS: A single guide can be digitally designed and 3D printed to perform controlled gingivectomy and minimally invasive tooth preparations. The outcome of the gingivectomy improved the gingival architecture for central incisors, and the ceramic veneers fulfilled the patient's esthetic demands.

Successful retreatment of a maxillary central incisor with a wide-open apex using MTA to fill the entire canal: 24-year follow-up.

Managing teeth with open apices can be a challenging scenario for clinicians. This case report describes the 24-year follow-up of a maxillary central incisor that failed to develop after a traumatic injury resulting in a wide-open apex. A 10-year-old girl presented complaining of discomfort in her upper teeth. Tooth #9 had received a traumatic blow several years before and was discoloured with a resin composite restoration on the mesio-incisal edge. The tooth was painful to percussion and palpation. An inadequate root canal filling and incomplete root formation were observed on the initial periapical radiograph. Root canal retreatment was initiated, and the canal filled entirely with mineral trioxide aggregate (MTA) because of the extremely wide canal and open apex. The patient was asymptomatic at the 24-year follow-up with the cone beam computed tomography and periapical radiographs demonstrating the stability of the MTA.

Perceptions, attitudes, and clinical experiences of Brazilian dental practitioners towards molar incisor hypomineralisation: a cross-sectional study.

PURPOSE: To evaluate perceptions, attitudes, and clinical experience of Brazilian dental practitioners regarding molar incisor hypomineralisation (MIH). METHODS: An online survey with 27 questions, covering professional profile data, perceptions, and knowledge on clinical management of MIH, was employed. Descriptive analyses, chi-square, Fisher's exact, and Cramer's V tests were used. RESULTS: Sample comprised 100 participants, equally distributed between those working in private or public sectors. Most private sector practitioners had 21-30 years of clinical experience (28%) and master's degree (50%), while most public sector practitioners had 11-20 years of clinical experience (32%) and a PhD degree (32%). Most participants (86%) recognized MIH in their practice. Statistically significant differences were observed in frequency (p = 0.001), incidence (p = 0.039), and lesion type (p = 0.043) between practitioners from both sectors. Uncertainly in management was reported by 49%, mainly in public sector. For mild MIH in incisors, no treatment was chosen (43%), and the treatment longevity was the only significant factor reported (p = 0.012). In cases of mild MIH in first permanent molars (FPMs), 51% of respondents opted to keep the affected tissue and apply fissure sealant. Glass ionomer (GI) restoration was commonly indicated for FPMs with severe MIH with moderate loss of structure and sensitivity (38%). In cases with substantial structural loss and pulpal involvement, the most chosen treatment was endodontic intervention combined with preformed crowns. CONCLUSION: Brazilian dental practitioners face MIH in clinical practice. Although, public sector professionals are less confident in diagnosis and treatment, no significant differences in treatment preferences between public and private sector dental practitioners were identified.

Challenges of Using Scoring Systems for the Assessment of Molar Incisor Hypomineralisation.

The dental professional is exposed to complex challenges daily, posed by molar incisor hypomineralisation (MIH). These range from understanding its etiology through to determining the most effective strategies for clinical management of the problem. Beyond any doubt, the choice of the diagnostic scoring system to be used for recording the condition is included among these challenges. To a certain degree, this is understandable since the development of specific diagnostic tools for recording the occurrence of MIH takes place parallel to the ongoing discoveries about the problem. Therefore, the aim of this chapter is to present different MIH scoring systems that have previously been proposed in the literature for detecting MIH and discuss their applications, advantages, and limitations.

Understanding the Enamel Disintegration and Posteruptive Breakdown of Demarcated Opacities on Molar Incisor Hypomineralisation.

This review aims to present scientific knowledge regarding the demarcated opacities of molar incisor hypomineralisation (MIH) and factors that clarify the occurrence of posteruptive enamel breakdown. The demarcated opacities have distinct boundaries with the adjacent nonaffected enamel and may vary in color among white, creamy, yellow, and brownish. The hypomineralised enamel is more porous and less organized than the nonaffected enamel. As a result of the reduced mineral content and higher protein content, the hypomineralised enamel shows a progressive reduction in its mechanical properties according to the opacity feature. Chemically, the protein content of MIH opacities is abnormally high, mainly composed by albumin, which is a serum protein usually not found in mature enamel. The highest protein content is seen in brown opacities, followed by yellow and white opacities, both with higher protein content than nonaffected enamel. The fact that the hypomineralised enamel is more fragile than the nonaffected enamel is supported not only by laboratorial findings but also by clinical prospective studies that observed an aggravation of MIH over time, as well as the correlation between the color of the demarcated opacities and the risk of posteruptive enamel breakdown. A better understanding about the microstructure of the hypomineralised enamel has relevant implications for the clinical approach of the condition. In the clinic, besides a comprehensive assessment of anamnesis and clinical data, it is advisable to record the color and the location of the opacities by tooth surface in order to support the treatment decisions and estimate a prognosis for MIH patients.

Re-Establishing the Esthetics of Incisors in Patients with Molar Incisor Hypomineralisation.

The awareness of molar incisor hypomineralisation (MIH) has led to its increased clinical detection, consequently drawing more attention to its associated complications. This text offers an overview of the esthetic management of anterior teeth affected by MIH, a condition characterized by enamel defects that present significant cosmetic challenges. The focus is on the clinical presentation of MIH characteristics, considering the depth of lesions and the clinical aspects, and the treatment protocols available, despite a lack of extensive scientific evidence. To the best of the current scientific knowledge, the text evaluates the potential of minimally invasive procedures, as well as the use of traditional composite resin techniques and their possible combinations, highlighting the critical role of esthetic considerations for the impacted anterior teeth. The chapter is augmented with five illustrative clinical cases that display the practical application of these treatment approaches. These examples articulate the clinical decision-making process and personalized restorative strategies, aiming to balance function with enhanced esthetic results. The described cases act as a roadmap for clinicians tackling the complexities of MIH treatment in the context of limited empirical evidence, providing insights into achieving both satisfactory and esthetically pleasing outcomes for patients suffering from this condition.

Impact of Molar Incisor Hypomineralisation on Quality of Life.

Oral health-related quality of life (OHRQoL) is a multifaceted concept that surpasses an exclusively clinical perception and includes functional, social, emotional, and environmental issues. The measure of OHRQoL represents a holistic approach for research and clinical practice. Negative impacts of oral conditions on OHRQoL in childhood can reflect on health development, especially in a life stage marked by social and cognitive maturation. Therefore, such problems can impact negatively on the daily lives of the individuals and their families. Individuals with molar incisor hypomineralisation (MIH) experience more frequent posteruptive breakdown, an elevated risk of tooth decay, filling failures, the need for recurrent dental treatment, and a higher prevalence of dental hypersensitivity. Children with severe MIH may struggle with everyday activities, such as brushing their teeth, speaking, smiling, chewing, and consuming hot or cold foods. MIH-affected incisors may exhibit opacities that can impact the aesthetics of their smiles. This condition may discourage children from smiling and can indirectly affect their parents as well. The management modalities are focused on solving functional, aesthetic, and hypersensitivity problems and to evaluate OHRQoL values before and after therapies. Therefore, this chapter aims to discuss how MIH affects the OHRQoL of children and the questionnaires that can be used to evaluate that impact.

Fluctuating arch symmetry: a comparison of two methods of assessment - applicability and efficiency.

INTRODUCTION: Symmetry is balance, some correspondence in the size, form, and arrangements of parts on opposite sides of a plane, line, or point. The opposite of this concept is asymmetry, or imbalance. OBJECTIVE: This retrospective study compared two methods for assessing arch symmetry with linear measurements based on triangles, to determine their applicability and efficiency. METHODS: Two groups were enrolled: children (n=20) and adults (n=20), and the arch symmetry was assessed from linear measurements. Method 1: the incisor-canine (INC), canine-molar (CM), and incisor-molar (INM) distances (paired t-test and Pearson correlation). Method 2: a mathematical equation between the cusps measurements of the canines and the distobuccal of the first molars leading to result 1 (t-test for one sample and bootstrapping analysis). Dental casts were digitized and analyzed using a software program. The Bland-Altman test compared the methods (α=0.05). RESULTS: The Bland-Altman test revealed concordance between the methods; however, separately the results were different: In method 1, the mandibular arch did not demonstrate correlation (children, INC r=0.33; CM r=0.45; INM r=0.51; adults, CM r=0.46; INM r=0.35), however, the maxilla revealed a strong correlation in children and a strong/moderate correlation in adults. In method 2, both arches were symmetrical (p>0.05). CONCLUSION: Method 1 may be appropriate during orthodontic treatment, and method 2 may be indicated for final treatment. These methods are useful; however, only method 1 identified the side of asymmetry. The methods can contribute to future studies in syndromic and non-syndromic patients, before and after orthognathic surgeries and orthodontic treatment, comparing results.

Root volume measurements of maxillary canines and lateral incisors in patients with unilateral maxillary canine impaction.

OBJECTIVE: This study aimed to assess root volumes of maxillary canines and adjacent lateral incisors in patients with unilateral maxillary canine impaction. METHODS: This cross-sectional study was performed on cone-beam computed tomography (CBCT) scans of 100 patients (49 females and 51 males) with unilateral maxillary canine impaction. The images were loaded in Planmeca Romexis Viewer, and root layers between the cementoenamel junction and apex were reconstructed at 600-µm intervals. At each layer, the root boundary was marked, and finally, the root volume was calculated by multiplying the layers' area by the thickness of 600 µm. The root size of canines and lateral incisors was compared between the impaction and normal eruption sides. RESULTS: Sixty-two patients showed buccal canine impaction, and 38 presented palatal impaction. The mean root volume of canines on the impaction side was significantly greater than that on the normal eruption side; either the tooth was buccally or palatally impacted (p<0.001). The lateral incisors on the side of buccally-impacted canines showed a significantly smaller root volume than that of the contralateral side (p<0.001). However, there was no significant difference in the root size of lateral incisors between the two sides in cases presenting palatal canine impaction (p=0.177). CONCLUSION: The difference in root volume of canines between the two sides can serve as an indicator of canine impaction. The reduction in the root size of the lateral incisor on the side of the buccally impacted canine may be due to root resorption created by pressure from the canine's crown.

Minimally invasive guided endodontic microsurgery with Zekrya bur: A 48-month follow-up case report.

Endodontic microsurgery guided by navigation systems represents a precise and minimally invasive approach for retreatment of apical periodontitis following failed conventional endodontic therapy. Accurate localization and minimal access to the root apex are paramount for successful outcomes and preservation of anatomical structures. Workflow considerations, such as three-dimensional (3D) virtual planning and endodontic guidance represent new crucial aspects for addressing complex cases. This clinical case report presents the successful reintervention of a complex case using a Zekrya bur, operative microscopy, cone beam computed tomography and biocompatible materials. After a 48-month follow-up, complete healing of the treated area was observed. This minimally invasive technique, employing a simple instrument widely available globally, underscores the potential for efficient and predictable outcomes in complex endodontic microsurgical retreatment.