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Localized sources of morphogens, called signalling centres, play a fundamental role in coordinating tissue growth and cell fate specification during organogenesis. However, how these signalling centres are established in tissues during embryonic development is still unclear. Here we show that the main signalling centre orchestrating development of rodent incisors, the enamel knot (EK), is specified by a cell proliferation-driven buildup in compressive stresses (mechanical pressure) in the tissue. Direct mechanical measurements indicate that the stresses generated by cell proliferation are resisted by the surrounding tissue, creating a circular pattern of mechanical anisotropy with a region of high compressive stress at its centre that becomes the EK. Pharmacological inhibition of proliferation reduces stresses and suppresses EK formation, and application of external pressure in proliferation-inhibited conditions rescues the formation of the EK. Mechanical information is relayed intracellularly through YAP protein localization, which is cytoplasmic in the region of compressive stress that establishes the EK and nuclear in the stretched anisotropic cells that resist the pressure buildup around the EK. Together, our data identify a new role for proliferation-driven mechanical compression in the specification of a model signalling centre during mammalian organ development.

Aim: Evaluate constitutional differences in chin morphology and volume, and mandibular tooth size, between different facial divergence patterns. Materials and Methods: The sample consisted of 284 pretreatment cone beam computed tomography (CBCT) images of growing and non‐growing patients who were stratified into 4 groups based on mandibular plane inclination to cranial base (SN) angle. Linear and angular measurements were made on the lateral CBCT images: mandibular lateral incisor crown (I‐C) total (I‐A) lengths, the distances between point D (centre of symphysis) and both incisor apex (D‐A) and menton (D‐Me) and between cemento‐enamel junction and menton (CEJ‐Me); chin width at the level of the central incisor apex (CWA) and point D (CWD); and the angles of the anterior and posterior symphyseal slopes. The volume of the symphysis was measured using a specialized 3D imaging software. Group differences and associations between parameters were gauged through the three‐way ANOVA analysis. Results: I‐C, I‐A, D‐A, D‐Me and CEJ‐Me were greater in the hyperdivergent group (p <.001). CWA and CWD were wider in the hypodivergent group (p =.003). Volume of the chin and inter‐slope angles were similar in all groups (p >.05). The anterior slope angle decreased with hyperdivegence (p <.005) in opposite pattern to the posterior slope angle (p <.005). Conclusions: Shape differences in mandibular symphysis were observed between opposite divergence patterns. Mandibular incisors were longer with hyperdivergence and shorter with hypodivergence. However, chin volumes were similar across divergence groups. These findings underline the role of genetic and environmental factors that impact facial growth. [ABSTRACT FROM AUTHOR]

Objective: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The AP-TADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (-0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54). However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions: In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted. [ABSTRACT FROM AUTHOR]

Background: The space caused by an impacted maxillary canine or missing lateral incisor, can lead to malocclusion and dental crowding. This study aimed to examine the skeletal pattern of patients with impaction or missing of maxillary canine or lateral teeth.Methods and Materials: In this cross sectional study, the panoramic and lateral cephalometric radiographs of 10-25-year-old patients presenting to the Orthodontic Department of Mashhad Dental School over a five-year period were retrieved and analyzed.A total of 103 patients with maxillary canine impaction or missing of the lateral incisor were selected as the case group, and 103 patients without these anomalies were included as controls. After cephalometric tracing, skeletal classes were determined based on SNA, SNB, ANB angles. Facial vertical height was assessed using Jaraback Index. Chi-Square tests and Independent samples T-tests were used for statistical analysis. P-value0.05). Skeletal Class II was the most common pattern in both groups; however, Skeletal Class III was more frequent in males with a missing lateral incisor. Although long facial height was more prevalent in the case group and normal facial height was more frequent in the control group, no significant differences in Jaraback index were observed between the groups (P=0.441).Conclusion: In this study, skeletal Class II was the most common pattern. Skeletal Class III was more common in males with a missing upper lateral incisor. Tendency to maxillary deficiency was seen in patients with a missing upper lateral incisor.

This case report describes the successful management of an oblique fracture of #11 with a fracture line that extended subgingivally by following a multidisciplinary protocol to preserve biological width and improve long-term prognosis. A 28-year-old male patient presented with a fractured front tooth caused by a fall. After a brief period of pain following the trauma, the patient was asymptomatic. An oblique fracture (Ellis Class III) in the coronal third of the upper right central incisor (#11 in the FDI teeth numbering system) with exposed pulp tissue was discovered during the routine clinical examination. When the fractured fragment was removed under local anesthesia, the fracture line was found to be extending subgingivally along the palatal aspect of the tooth. A multidisciplinary approach involving endodontic therapy and periodontal management involving flap reflection was adopted to attain a favorable long-term prognosis. The therapy comprised root canal treatment, crown lengthening, mucoperiosteal flap reflection, osseous re-contouring, composite core build-up, and final restoration using a porcelain fused to metal crown. This multidisciplinary approach, at 1-year follow-up, showed uneventful healing, and was able to achieve excellent esthetics and function while also preserving the patient's natural tooth. [ABSTRACT FROM AUTHOR]

This case report describes the treatment of a 9-year-old boy with impacted maxillary central incisors due to 2 supernumerary teeth. A sequential approach comprising of surgical removal of the supernumerary teeth and 2 stages of surgical exposure and orthodontic traction of the impacted teeth resulted in correct repositioning of incisors. Close monitoring and multidisciplinary cooperation during various stages of treatment led to a successful esthetic outcome, with optimal periodontal health and functional occlusion.

Abstract Mammalian dentition exhibits distinct heterodonty, with more simple teeth located in the anterior area of the jaw and more complex teeth situated posteriorly. While some region-specific differences in signalling have been described previously, here we performed a comprehensive analysis of gene expression at the early stages of odontogenesis to obtain complete knowledge of the signalling pathways involved in early jaw patterning. Gene expression was analysed separately on anterior and posterior areas of the lower jaw at two early stages (E11.5 and E12.5) of odontogenesis. Gene expression profiling revealed distinct region-specific expression patterns in mouse mandibles, including several known BMP and FGF signalling members and we also identified several new molecules exhibiting significant differences in expression along the anterior–posterior axis, which potentially can play the role during incisor and molar specification. Next, we followed one of the anterior molecules, SATB2, which was expressed not only in the anterior mesenchyme where incisor germs are initiated, however, we uncovered a distinct SATB2-positive region in the mesenchyme closely surrounding molars. Satb2-deficient animals demonstrated defective incisor development confirming a crucial role of SATB2 in formation of anterior teeth. On the other hand, ectopic tooth germs were observed in the molar area indicating differential effect of Satb2-deficiency in individual jaw regions. In conclusion, our data provide a rich source of fundamental information, which can be used to determine molecular regulation driving early embryonic jaw patterning and serve for a deeper understanding of molecular signalling directed towards incisor and molar development.

Elephants are known for strongly lateralized trunk behaviors, but the mechanisms driving elephant lateralization are poorly understood. Here, we investigate features of elephant mouth organization that presumably promote lateralization. We find the lower jaw of elephants is of narrow width, but is rostrally strongly elongated even beyond the jaw bone. Elephant lip vibrissae become progressively longer rostrally. Thus, elephants have two lateral dense, short microvibrissae arrays and central, less dense long macrovibrissae. This is an inversion of the ancestral mammalian facial vibrissae pattern, where central, dense short microvibrissae are flanked by two lateral macrovibrissae arrays. Elephant microvibrissae have smaller follicles than macrovibrissae. Similar to trunk‐tip vibrissae, elephant lip microvibrissae show laterally asymmetric abrasion. Observations on Asian zoo elephants indicate lateralized abrasion results from lateralized feeding. It appears that the ancestral mammalian mouth (upper and lower lips, incisors, frontal microvibrissae) is shaped by oral food apprehension. The elephant mouth organization radically changed, however, because trunk‐mediated feeding replaced oral apprehension. Such elephant mouth changes include the upper lip–nose fusion to the trunk, the super‐flexible elongated lower jaw, the loss of incisors, and lateral rather than frontal microvibrissae. Elephants' specialization for lateral food insertion is reflected by the reduction in the centering effects of oral food apprehension and lip vibrissae patterns. [ABSTRACT FROM AUTHOR]

Objectives: This ex vivo study aimed to evaluate the influence of different filling techniques on the filling removal from oval root canals filled with bioceramic sealer. Methods: Thirty-six mandibular incisors with single oval canals were filled with bioceramic sealer following the techniques (n = 12): single-cone, modified McSpadden, or continuous wave of condensation, and scanned by micro-computed tomography (micro-CT). The filling was removed using the Clearsonic ultrasound tip and Reciproc system up to the R40 instrument, and the working time was recorded. The teeth were scanned again by micro-CT. Percentage of remnant volume (mm³) of the filling material, dentin thickness, and root canal transportation were measured. The data was analyzed using parametric and non-parametric tests with a significance level of 5%. Results: It took more time to remove the filling material using the continuous wave of condensation technique (p < 0.05), followed by the modified McSpadden and single-cone techniques. There was no difference (p > 0.05) when comparing the percentage of remaining filling material among the three groups, nor did it among the segments of each tooth. There was also no difference in the analysis of dentin thickness and transportation when comparing the groups (p > 0.05). Conclusions: The filling technique did not influence the amount of remaining filling material, dentin thickness, and transportation. The working time was longer with thermoplastic filling techniques. Clinical relevance: Endodontic retreatment in teeth filled with bioceramic sealers increases with their use. Several techniques are used to fill the root canals, thus, it is important to know whether the filling technique influences the non-surgical endodontic retreatment. [ABSTRACT FROM AUTHOR]

Human teeth are unique since one population’s dental pattern might differ from another. Such specific dental characteristics, such as the incisor, are observable in each dentition. Objective: his study analyzed the population differences in Javanese and Chinese-Indonesian populations through observations of the incisal traits, namely winging, shoveling, and double shoveling. Methods: 50 dental casts (76 Javanese samples and 74 Chinese-Indonesian samples) were obtained from Dr. Myrtati Dyah Artaria’s private collection, stored in the Faculty of Medicine, Universitas Airlangga. The traits were observed and scored using the Arizona State University Dental Anthropology System (ASUDAS) and analyzed statistically using crosstab and chi-square methods. Results: Only three out of 13 test results exhibit significant differences (p < 0.05). Conclusion: The dentitions observed in the Chinese-Indonesian samples mirror the immense Chinese acculturation into Javanese cultures through interbreeding that happened generations ago. The gene flow between these two populations appears phenotypically in the dentitions, leading the Chinese-Indonesian samples in this study to express Sundadont traits despite their noticeable facial traits and heritage. [ABSTRACT FROM AUTHOR]

Objectives: The use of fiber posts in endodontically treated primary maxillary central incisors improves the retention of composite resin restorations. The purpose of this study was to evaluate the effect of 4 different luting cements on fracture resistance of primary maxillary central incisors with fiber posts. Materials and Methods: In this in vitro study, 40 primary maxillary central incisors were endodontically treated and obturated with Metapex. They were then randomly divided into four groups (n=10) for cementation of fiber posts with GC Fuji I glass ionomer luting cement, Panavia F2.0 dual-cure luting cement, Panavia SA Luting Plus cement (self-adhesive), and TotalCem self-adhesive cement. After 1000 thermal cycles, the fracture resistance was measured. Data were statistically analyzed using ANOVA (alpha=0.05). Results: The mean fracture resistance was 267.07±130.01N in TotalCem, 257.27±102.56N in Panavia F2.0 dual-cure cement, 227.82±110.40N in Panavia SA Luting Plus self-adhesive cement, and 220.89±59.96N in GC Fuji I glass ionomer group. There was no statistically significant difference in fracture resistance among the four groups (P=0.714). Conclusion: Type of luting cement had no significant effect on fracture resistance of primary maxillary central incisors with fiber posts. Nonetheless, TotalCem yielded the highest fracture resistance. Considering its self-adhesive property and easy workability, it can be a good option for cementation of fiber posts in endodontically treated primary central incisors. [ABSTRACT FROM AUTHOR]

Copyright of Dental Press Journal of Orthodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Guiding the eruption for the development of functionally stable and socially acceptable occlusion in children is crucial on a pediatric dentist's perspective. Ectopic eruption refers to a condition where a tooth deviates from its normal path of eruption and is not in its usual position Ectopic eruption mostly involve maxillary incisors, accounting for about 5 percent. In primary dentition, luxation injuries are the most prevalent kind of TDI. Permanent incisors are at a higher risk of developing post-traumatic complications because they are closely related to the apices of primary incisors.Usually, fixed appliances are used to treat such ectopic eruption. This case report discusses the successful management of an 8-year old Indian boy who had an unusual ectopic eruption of his maxillary left central incisor by a novel removable appliance approach. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess membrane use with a bone substitute graft for guided bone regeneration (GBR) in experimental dehiscence defects. Materials and methods: Maxillary second incisors (I2) in 9 dogs were extracted. Six weeks later, implants were inserted and experimental dehiscence defects (5 × 3 mm) created on the buccal aspect. The defects and surrounding bone were grafted with deproteinized bovine bone mineral. One side (test) was covered with a resorbable collagen membrane whereas the contralateral side (control) was not. After 6 weeks, histomorphometrical analysis was performed to evaluate: (a) first bone-to-implant contact (fBIC), (b) buccal bone thickness at 1 mm increments from implant shoulder, (c) regenerated area (RA), (d) area and percentages of new bone (B), bone substitute (BS) and mineralized tissue (MT). Results: The histological appearance was similar between test and control sites. At central and lateral sections, there were no differences between groups for fBIC, buccal bone thickness, RA, BS, B, %B, MT and %MT. At central sections, membrane use favoured more %BS and %MT (p = 0.052). There was significantly more B, %B and MT at lateral compared to central sections. Conclusions: Membrane use tended to retain more bone substitute, but had no effect on new bone ingrowth. Lateral sections showed significantly more bone ingrowth and mineralized tissue compared to central sections, confirming that new bone ingrowth takes place mainly from the lateral walls of the defect. Clinical relevance: Preclinical research to clarify the dynamics of bone regeneration in GBR procedures is relevant in clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to provide insights into the developmental characteristics of the upper lateral incisor in individuals with unilateral clefts. Materials and methods: Panoramic radiographs of a consistent group of Caucasian children taken over time (ages 6, 9, and 12) were extensively reviewed. The study assessed the distribution pattern, eruption path, tooth development, and crown size of the upper lateral incisor within the cleft region. Results: The most commonly observed distribution pattern was the lateral incisor located distal to the cleft, accounting for 49.2% of cases. Furthermore, a significant delay in tooth development of the upper lateral incisor on the cleft side was noted at ages 6 and 9 (p > 0.001). Compared with the non-cleft side, these incisors often erupted along the alveolar cleft and exhibited microdontia (88.3%, p < 0.041). Conclusion: Lateral incisors on the cleft side display unique distribution patterns, microdontia, and delayed tooth development. Careful monitoring of the cuspid eruption is essential, as it can influence the eruption of the lateral incisor. Clinical relevance: A comprehensive understanding of the development of the upper lateral incisor relative to the cleft is vital for determining its prognosis over time. The position of the upper lateral incisor can also influence the timing and prognosis of secondary alveolar bone grafting. Preserving the upper lateral incisor favors arch length, perimeter, and symmetry in individuals with unilateral clefts. [ABSTRACT FROM AUTHOR]

ABSTRACT 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

Purpose: Restoring the esthetics of anterior teeth with implants is challenging. This study aimed to evaluate the esthetic outcome of interproximal papilla between implant-restored unilateral and bilateral maxillary central incisors. Materials and Methods: A total of 56 adults with implant restorations in the maxillary central incisors were enrolled, including 40 cases of unilateral incisors and 16 cases of bilateral incisors. Photographic and radiographic assessments were performed, and patient-reported esthetic satisfaction was collected. Results: The papilla index (PI) in the unilateral group was superior to that in the bilateral group (P = .002). Patients in the two groups reported equal satisfaction regarding the final esthetic outcome (P = .470). Statistically significant differences were noted between the two groups in papilla height (P = .000), implant-implant or implant-tooth distance (P = .002), and vertical distance from the implant platform to the bone crest (P = .000). In the bilateral group, tested variables were not correlated with PI by nonparametric Spearman correlation. In the unilateral group, the multivariate binary logistic regression model showed that incomplete papilla fill was associated with abutment type (OR = 0.019), implant-tooth distance (range, 2.1 to 6.2 mm; OR = 6.435), and distance from the bone crest to the contact point (range: 3.5 to 6.9 mm; OR = 4.589). Conclusion: In implant-restored maxillary central incisors, PI in the unilateral group was superior to that in the bilateral group. In the bilateral group, no clinical variable was correlated with PI. In the unilateral group, the risk of incomplete papilla fill was reduced by the customized zirconia abutment and was increased by the larger implant-tooth distance and higher distance from the bone crest to the contact point. [ABSTRACT FROM AUTHOR]

Abstract Background Rehabilitation of the anterior area when the mesio-distal space is reduced is a challenge for the clinician, due to the patient’s anatomical limitations and aesthetic requirements. Narrow Diameter Implants (NDI) are an option of treatment when the standard diameter implant is not possible, but the evidence is scarce. This prospective clinical study aims to analyze the formation of the tooth-implant papilla between the implant and the adjacent natural tooth in the maxillary lateral incisors and mandibular incisors. Methods A total of 40 patients treated with NDI, of titanium-zirconium (Ti-Zr) alloy i.e., 2.9 mm Test Group (TG) and 3.3 mm Control Group (CG), were included. The mesiodistal distance between the adjacent natural teeth was used for implant selection, maintaining 1.5 mm between the fixation and the adjacent tooth. Clinical assessment was performed by a clinical examiner at 6 and 12 months after the final prosthesis. The primary variable was the Jemt Papillary Index. Also, implant survival rate (SR), complications, Implant Stability Quotient (ISQ), and patient-reported outcomes measures (PROMs) such as aesthetics, chewing, phonation, comfort, and self-esteem were analyzed. Results A significant amount of papilla filling was observed concerning the baseline, with a trend towards more formation of the papilla in the TG, with a JPI score of 3. No significant differences were observed between the two groups regarding implant SR, clinical parameters, and complications. In terms of PROMs, a higher satisfaction in the TG was observed, with significant intergroup differences for aesthetics, comfort, self-esteem, and primary stability ISQ (TG: 59.05 (SD: 5.4) vs. CG: 51.55 (SD: 5.7)). Conclusions The 2.9 mm diameter Ti-Zr implants achieved a formation of papilla similar to 3.3 mm implants in the anterior region at 12 months of follow-up after the final prosthetic restoration. The use of Ti-Zr implants with a diameter of 2.9 mm to rehabilitate single teeth in areas of the anterior region, where the mesiodistal distance is limited, showed favorable clinical results and a high degree of satisfaction during 1 year of observation similar to 3.3 mm dental implants. Trial registration This study was retrospectively registered in ClinicalTrials.gov with the number NCT05642520, dated 18/11/2022.

Copyright of Turkiye Klinikleri Journal of Dental Sciences is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Rehabilitation of the anterior area when the mesio-distal space is reduced is a challenge for the clinician, due to the patient's anatomical limitations and aesthetic requirements. Narrow Diameter Implants (NDI) are an option of treatment when the standard diameter implant is not possible, but the evidence is scarce. This prospective clinical study aims to analyze the formation of the tooth-implant papilla between the implant and the adjacent natural tooth in the maxillary lateral incisors and mandibular incisors. Methods: A total of 40 patients treated with NDI, of titanium-zirconium (Ti-Zr) alloy i.e., 2.9 mm Test Group (TG) and 3.3 mm Control Group (CG), were included. The mesiodistal distance between the adjacent natural teeth was used for implant selection, maintaining 1.5 mm between the fixation and the adjacent tooth. Clinical assessment was performed by a clinical examiner at 6 and 12 months after the final prosthesis. The primary variable was the Jemt Papillary Index. Also, implant survival rate (SR), complications, Implant Stability Quotient (ISQ), and patient-reported outcomes measures (PROMs) such as aesthetics, chewing, phonation, comfort, and self-esteem were analyzed. Results: A significant amount of papilla filling was observed concerning the baseline, with a trend towards more formation of the papilla in the TG, with a JPI score of 3. No significant differences were observed between the two groups regarding implant SR, clinical parameters, and complications. In terms of PROMs, a higher satisfaction in the TG was observed, with significant intergroup differences for aesthetics, comfort, self-esteem, and primary stability ISQ (TG: 59.05 (SD: 5.4) vs. CG: 51.55 (SD: 5.7)). Conclusions: The 2.9 mm diameter Ti-Zr implants achieved a formation of papilla similar to 3.3 mm implants in the anterior region at 12 months of follow-up after the final prosthetic restoration. The use of Ti-Zr implants with a diameter of 2.9 mm to rehabilitate single teeth in areas of the anterior region, where the mesiodistal distance is limited, showed favorable clinical results and a high degree of satisfaction during 1 year of observation similar to 3.3 mm dental implants. Trial registration: This study was retrospectively registered in ClinicalTrials.gov with the number NCT05642520, dated 18/11/2022. [ABSTRACT FROM AUTHOR]

Introduction: Treating anterior restorations is a real challenge for a dentist and conventional protocols are not always applicable. The aim of this study is to determine different therapeutic to conducting anterior restorations in disabled people. Case report: We begin by presenting the case of a 23‐year‐old, handicapped man, who was brought in consultation to compensate for the loss of the left upper central incisor (#21). Materials and methods: We then performed a systematic literature review in December 2022, in accordance with the PRISMA guidelines. The publications, on three databases, dealing with dental treatments on disabled people were selected whether they were clinical studies or case reports. Results: In the end, 14 publications were included. Most of the treatments described in the studies (n = 10; 71.43%) concern people aged under 19. The patients present different types of handicaps with various degrees of severity and the oral diseases described are as heterogeneous as the handicaps retrieved. Discussion: It is therefore difficult to make common treatment recommendations for all these variable profiles and situations. Most of patients in this study are very young, so there is a need for preventive and therapeutic care as earlier as possible, to preserve the vitality of their teeth and dental occlusion. [ABSTRACT FROM AUTHOR]

Objectives: The use of fiber posts in endodontically treated primary maxillary central incisors improves the retention of composite resin restorations. The purpose of this study was to evaluate the effect of 4 different luting cements on fracture resistance of primary maxillary central incisors with fiber posts. Materials and Methods: In this in vitro study, 40 primary maxillary central incisors were endodontically treated and obturated with Metapex. They were then randomly divided into four groups (n=10) for cementation of fiber posts with GC Fuji I glass ionomer luting cement, Panavia F2.0 dual-cure luting cement, Panavia SA Luting Plus cement (self-adhesive), and TotalCem self-adhesive cement. After 1000 thermal cycles, the fracture resistance was measured. Data were statistically analyzed using ANOVA (alpha=0.05). Results: The mean fracture resistance was 267.07±130.01N in TotalCem, 257.27±102.56N in Panavia F2.0 dual-cure cement, 227.82±110.40N in Panavia SA Luting Plus self-adhesive cement, and 220.89±59.96N in GC Fuji I glass ionomer group. There was no statistically significant difference in fracture resistance among the four groups (P=0.714). Conclusion: Type of luting cement had no significant effect on fracture resistance of primary maxillary central incisors with fiber posts. Nonetheless, TotalCem yielded the highest fracture resistance. Considering its self-adhesive property and easy workability, it can be a good option for cementation of fiber posts in endodontically treated primary central incisors.

Objective: This study investigated torque expression in maxillary incisors using two passive self-ligating bracket types (Damon Q and Pitts 21) placed at different heights using the Finite element method. Materials and methods: Two passive self-ligating brackets, Damon Q (Ormco, USA) and Pitts 21 (OC Orthodontics, USA) were 3D modeled using micro-computed tomography. Damon Q (0.022ˮ x 0.028″ slot size) and Pitts 21 (0.021ˮ x 0.021″ slot size) brackets were placed on a maxillary central incisor at predetermined vertical heights. Arch wires of size 0.019ˮ x 0.025″ stainless steel (Damon Q) and 0.020ˮ x 0.020” Titanium Molybdenum (Pitts 21) were placed in the bracket slots. Results: Pitts 21 brackets showed higher torquing moments at all bonding heights as compared to Damon Q brackets. The minimum torquing moment was 9.03Nmm at 5 mm for Damon Q and the maximum torquing moment was 14.92Nmm for Pitts 21 at a bracket bonding height of 8 mm. Total deformation for Pitts 21 at a height of 5 mm from the incisal edge was 0.61 × 10−6mm as compared to that of Damon Q which was 0.41 × 10−6mm. Lowest Von Mises stress values were at 27.07 MPa in Damon Q brackets at a bracket height of 5 mm from the incisal edge. Highest Von Mises stress values were 36.80 MPa for Pitts 21 brackets at a bracket height of 8 mm from the incisal edge. Conclusion: Pitts 21 brackets exhibited superior torquing characteristics compared to Damon Q. Total deformation in Pitts 21 was higher than Damon Q at all tested bracket bonding heights.

Objective: To evaluate the effectiveness of a diode laser (810 nm) for circumferential supracrestal fiberotomy compared with conventional surgical circumferential supracrestal fiberotomy in preventing rotational relapse in orthodontically treated cases. Methods: Seventy-six patients (age range from 18-25 years) with mandibular crowding ranging between 5-8 mm and rotation >10˚ (from the individualized arch form) treated non-extraction with a straight wire appliance (McLaughlin, Bennet, Trevisi; 0.022 inch) prescription were selected for the study. The patients were randomly allocated into 3 groups of 22 patients each: Group 1 (Control group-No circumferential supracrestal fiberotomy), Group 2 (Conventional circumferential supracrestal fiberotomy), and Group 3 (diode laser circumferential supracrestal fiberotomy). After leveling and alignment up to “0.019x0.025” stainless steel wire, the arch wire was removed for a period of 1 month. Impressions were made and the poured casts were scanned. The 3D models (.STL files) were evaluated for changes in the irregularity index and rotational relapse. Results: One-way ANOVA and post-hoc Tukey’s test were used for data analysis. Group 1 (Control group) showed greater relapse in both irregularity index and rotation angulations in comparison with Groups 2 and 3, which was statistically significant (p

Alternative splicing generates distinct mRNA variants and is essential for development, homeostasis, and renewal. Proteins of the serine/arginine (SR)-rich splicing factor family are major splicing regulators that are broadly required for organ development as well as cell and organism viability. However, how these proteins support adult organ function remains largely unknown. Here, we used the continuously growing mouse incisor as a model to dissect the functions of the prototypical SR family protein SRSF1 during tissue homeostasis and renewal. We identified an SRSF1-governed alternative splicing network that is specifically required for dental proliferation and survival of progenitors but dispensable for the viability of differentiated cells. We also observed a similar progenitor-specific role of SRSF1 in the small intestinal epithelium, indicating a conserved function of SRSF1 across adult epithelial tissues. Thus, our findings define a regulatory mechanism by which SRSF1 specifically controls progenitor-specific alternative splicing events to support adult tissue homeostasis and renewal.

Abstract Objective To investigate the CBCT findings of the apical anatomy of immature maxillary central incisors. Methods CBCT images of 100 immature maxillary central incisors in Nolla 8 and 100 immature maxillary central incisors in Nolla 9 were collected. The mesiodistal and carniocaudal diameters of the apical foramen of immature maxillary central incisors were measured by software included with CBCT, as well as the mesiodistal, carniocaudal and facioligual diameters of the apical shadow. The apical shadow and apical foramen diameters were compared between Nolla 8 and Nolla 9. Data were analyzed using the MedCalc software package. Results For immature maxillary central incisors, the mesiodistal and facioligual diameters of the apical foramen were 2.75±0.68 mm and 3.28±0.74 mm in Nolla 8 and 1.50±0.51 mm and 1.92±0.79 mm in Nolla 9. The mesiodistal, facioligual and carniocaudal diameters of the apical shadow were 3.84±0.73 mm, 4.49±0.68 mm and 3.41±1.27 mm in Nolla 8 and 2.76±0.60 mm, 3.41±0.80 mm and 2.06±0.65 mm in Nolla 9, respectively. Conclusions The immature maxillary central incisors in Nolla 8 have a larger apical shadow and apical foramen than those in Nolla 9. The apical region of the maxillary central incisors in Nolla 8 was more likely to have a broad, blurred lamina dura. With the development of the apical foramen, the lamina dura in the apical region tended to be clear and sharp. Clinical significance To our knowledge, this is the first study to radiologically analyse the in vivo anatomy of the apical foramen and apical shadow of immature maxillary central incisors. The results of this study provide a more detailed understanding of the apical anatomy of the immature maxillary central incisor for the diagnosis and treatment of apical lesions.

Introduction: Retrospective studies have found conflicting results regarding the relationship between lower incisor inclination and the development of gingival recession (GR) after orthodontic treatment. Objective: This study aimed to investigate the relationship between lower incisor inclination and alveolar process (AP) and mandibular symphysis (MS) thickness in the development of GR. Materials and Methods: Frontal intraoral photography and cephalometric radiography were conducted before (T0) and after (T1) orthodontic treatment of 62 subjects. The presence of GR was considered when the cementoenamel junction was visible in the lower incisor on the frontal intraoral photograph. The circumstances for improvement, stability, and worsening of the gingival situation were based on the reduction, maintenance, and increase in the number of lower incisors with GR before and after treatment. To measure the incisor-mandibular plane angle (IMPA) and the thickness of the AP and the MS were used the cephalometric radiographs. Results: Men had a significantly thicker MS than women at T0 and T1 (p

ABSTRACT Objective: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. Methods: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). Results: Individuals’ mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. Conclusion: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

Traumatic dental injuries (TDIs) have significant long-term consequences for the oral cavity's hard and soft tissues. Alveolar process fractures are particularly complicated. This case report describes the management and 12-month follow-up of a segmental maxillary alveolar process fracture involving laterally luxated primary incisors. A case of a 4-year-old boy was reported to the hospital 1 hour after an accidental fall at school, which resulted in a fracture of the maxillary alveolar process. Emergency treatment consisted of fracture reduction and repositioning of the primary incisors, followed by a semirigid splint between maxillary canines. The splints were removed at the end of week 4, and the affected primary incisors remained asymptomatic.

Simple Summary: In past populations, some individuals used their front teeth as tools for purposes other than eating, such as making tools or preparing food. These activities have an impact on both the visible part of the tooth (crown) through wear, as well as the part anchored deep in the gum (tooth root) by causing excessive production of a mineralized tissue called 'cementum'. Cementum surrounds the tooth root and forms throughout an individual's life. It records information about the individual's oral health, physiology, and chewing activities. Under certain conditions (e.g., significant mechanical stress or infection), cementum production becomes excessive and exceeds normal physiological limits, resulting in 'hypercementosis'. The present study aims to identify different patterns of cementum apposition and to propose probable causes. We examined a sample of 35 teeth (Sains-en-Gohelle, France, 7th–17th century) and identified four groups of cementum apposition: (i) impacted teeth that never erupted in the mouth, (ii) infected teeth, with caries or gum disease, (iii) hyperfunctional teeth subjected to high mechanical stress, and (iv) hypofunctional teeth that were not used in chewing due to the loss of opposing teeth. We conclude that hypercementosis could provide information on the life history of archeological specimens, even based on isolated teeth. The "teeth-as-tools" hypothesis posits that Neanderthals used their anterior teeth as a tool or a third hand for non-dietary purposes. These non- or para-masticatory activities (e.g., tool-making or food preparation prior to ingestion) have also been described in other past and extant human populations, and other Primates. Cementum is the mineralized tissue that covers the tooth root surface and anchors it to the alveolar bone. Under certain conditions (e.g., mechanical stress, infection), its production becomes excessive (i.e., beyond the physiological state) and is called 'hypercementosis'. Several studies in dental anthropology have established a correlation between the teeth-as-tools and hypercementosis. The present work aims to characterize the different patterns of cementum apposition on archeological teeth and discuss their supposed etiology. Using microtomography and confocal microscopy, the patterns of cementum apposition (i.e., thickness, location, and surface characteristics) were analyzed in 35 hypercementotic teeth (Sains-en-Gohelle, France; 7th–17th c. A.D.). Four groups were identified with distinct hypercementosis patterns: (1) impacted, (2) infected, (3) hypofunctional, and (4) hyperfunctional teeth. Characterizing hypercementosis can contribute to documenting the oral health status (paleopathology) and/or masticatory activity of individuals, even from isolated teeth. This has implications for the study of fossil hominins, particularly Neanderthals, known for their use of anterior teeth as tools and frequent and substantial occurrence of hypercementosis. [ABSTRACT FROM AUTHOR]

Root resorption is a process that results in the loss of dental hard tissues as a result of odontoclastic action. One of the types of external resorption is external cervical resorption, which usually manifests itself in the cervical aspect of the teeth. Clinically, external root resorption is usually asymptomatic. When external cervical resorption occurs, cervical cavitation, gingival contour irregularity, or pink discoloration of the overlying enamel can often be observed. This case report describes the clinical and radiologic diagnosis (cone beam computed tomography) and treatment of external cervical resorption according to the current guidelines of the European Society of Endodontology. After 4 years, the tooth remained functional and the esthetic effect was satisfactory. [ABSTRACT FROM AUTHOR]

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This study investigated torque expression in maxillary incisors using two passive self-ligating bracket types (Damon Q and Pitts 21) placed at different heights using the Finite element method. Two passive self-ligating brackets, Damon Q (Ormco, USA) and Pitts 21 (OC Orthodontics, USA) were 3D modeled using micro-computed tomography. Damon Q (0.022ˮ x 0.028″ slot size) and Pitts 21 (0.021ˮ x 0.021″ slot size) brackets were placed on a maxillary central incisor at predetermined vertical heights. Arch wires of size 0.019ˮ x 0.025″ stainless steel (Damon Q) and 0.020ˮ x 0.020" Titanium Molybdenum (Pitts 21) were placed in the bracket slots. Pitts 21 brackets showed higher torquing moments at all bonding heights as compared to Damon Q brackets. The minimum torquing moment was 9.03Nmm at 5 mm for Damon Q and the maximum torquing moment was 14.92Nmm for Pitts 21 at a bracket bonding height of 8 mm. Total deformation for Pitts 21 at a height of 5 mm from the incisal edge was 0.61 × 10−6mm as compared to that of Damon Q which was 0.41 × 10−6mm. Lowest Von Mises stress values were at 27.07 MPa in Damon Q brackets at a bracket height of 5 mm from the incisal edge. Highest Von Mises stress values were 36.80 MPa for Pitts 21 brackets at a bracket height of 8 mm from the incisal edge. Pitts 21 brackets exhibited superior torquing characteristics compared to Damon Q. Total deformation in Pitts 21 was higher than Damon Q at all tested bracket bonding heights. [Display omitted] [ABSTRACT FROM AUTHOR]

OBJECTIVE: This retrospective clinical study was performed to determine the suitability and success rate of endodontic treatment of equine incisors presenting with apical and periapical disease. ANIMALS: All horses presented to a referral equine dental clinic between March 2013 and December 2019 specifically selected as candidates suitable for endodontic treatment were included in this study. METHODS: Initial clinical and radiographic presentation of incisor disorder cases suitable for endodontic treatment were recorded (88 incisors) and follow-up examination for long-term viability (8 months to 5 years) was performed in cases involving 32 incisors in total. RESULTS: A total of 68 horses with 88 incisors were included in this study for endodontic restorative treatment. Different dental materials were used, with a temporary 3-layered technique using calcium hydroxide apically and temporary cement and resin composite occlusally most commonly used at the first treatment. Complete obturation with resin composite was performed in 48% of the cases requiring second treatments (50 incisors). Follow-up examination involving 32 incisors showed that successful endodontic treatment was achieved in 75% of the teeth treated. CLINICAL RELEVANCE: Endodontic treatment of diseased incisors is a viable option in equid patients with a success rate comparable to humans in practice. The use of flowable resin composite as an obturation material has been shown to be successful at either the second treatment or in carefully selected patients at the first treatment. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effectiveness of a diode laser (810 nm) for circumferential supracrestal fiberotomy compared with conventional surgical circumferential supracrestal fiberotomy in preventing rotational relapse in orthodontically treated cases. Methods: Seventy-six patients (age range from 18-25 years) with mandibular crowding ranging between 5-8 mm and rotation >10˚ (from the individualized arch form) treated non-extraction with a straight wire appliance (McLaughlin, Bennet, Trevisi; 0.022 inch) prescription were selected for the study. The patients were randomly allocated into 3 groups of 22 patients each: Group 1 (Control group-No circumferential supracrestal fiberotomy), Group 2 (Conventional circumferential supracrestal fiberotomy), and Group 3 (diode laser circumferential supracrestal fiberotomy). After leveling and alignment up to “0.019x0.025” stainless steel wire, the arch wire was removed for a period of 1 month. Impressions were made and the poured casts were scanned. The 3D models (.STL files) were evaluated for changes in the irregularity index and rotational relapse. Results: One-way ANOVA and post-hoc Tukey’s test were used for data analysis. Group 1 (Control group) showed greater relapse in both irregularity index and rotation angulations in comparison with Groups 2 and 3, which was statistically significant (p<0.001). There was no statistically significant difference in irregularity index and rotational relapse between Group 2 and Group 3 (p=0.35 for irregularity index, and p=0.41 for rotational relapse). Conclusion: The control group showed significantly more relapse than both circumferential supracrestal fiberotomy groups. Both conventional and diode laser circumferential supracrestal fiberotomy decreased the relapse tendency. [ABSTRACT FROM AUTHOR]

Histone lactylation on its lysine (K) residues has been reported to have indispensable roles in lung fibrosis, embryogenesis, neural development, inflammation, and tumors. However, little is known about the lactylation activity towards histone lysine residue during tooth development. We investigated the dynamic patterns of lactate-derived histone lysine lactylation (Kla) using a pan-Kla antibody during murine tooth development, including lower first molar and lower incisor. The results showed that pan-Kla exhibited temporo-spatial patterns in both dental epithelium and mesenchyme cells during development. Notably, pan-Kla was identified in primary enamel knot (PEK), stratum intermedium (SI), stellate reticulum (SR), dental follicle cells, odontoblasts, ameloblasts, proliferating cells in dental mesenchyme, as well as osteoblasts around the tooth germ. More importantly, pan-Kla was also identified to be co-localized with neurofilament during tooth development, suggesting histone lysine lactylation may be involved in neural invasion during tooth development. These findings suggest that histone lysine lactylation may play important roles in regulating tooth development. [ABSTRACT FROM AUTHOR]

INTRODUCTION: This study aimed to evaluate the effect of upper central incisors on the upper lip after fixed orthodontic treatment. METHODS: In this retrospective study, 30 individuals aged between 202 and 278 months whose lateral cephalometric radiographs were evaluated at the beginning and end of treatment were included. The study was divided into two groups: Group A, in which the upper incisors protruded by 0–1 mm, and Group B, in which they protruded by 1–3 mm. The soft tissue nasolabial angle, upper lip thickness, and upper lip protrusion values were compared at the beginning and end of treatment in both groups. A Mann-Whitney U test was used to determine the relationship between continuous variables, and Spearman correlation coefficient was used to determine the relationship between these variables. RESULTS: The mean upper incisor protrusion was 0.49 +- 0.3 mm for Group A and 2.29 +- 0.56 mm for Group B. The nasolabial angle was -0.57 +- 1.13° in Group A and -3.78 +- 76° in Group B. The lip thickness was 0.18 +- 0.14 mm in Group A and -0.73 +- 0.49 mm in Group B. The upper lip protrusion was 0.34 +- 0.45 mm for Group A and 1.48 +- 0.45 mm for Group B. There was a statistically significant difference between the groups for all three values (p = 0.001). DISCUSSION AND CONCLUSION: Upper incisor protrusion was used to determine a decrease in nasolabial angle and a decrease in upper lip protrusion. However, when the protrusion amount increased, a decrease in lip thickness was observed.

The current systematic review appraises the effectiveness of the types of tooth movements performed with Invisalign® clear aligner on the maxillary incisors. An electronic literature search of published trials was performed through PubMed, LILACS, Scopus, Cochrane Library, and Web of Science databases, and selected journals, from 2009 to 2020. Out of 291 references, five relevant publications were identified for analysis: four studies were performed retrospectively and one prospectively, all non-randomized. Despite the limited set of selected articles, the sample size is significant, with 148 subjects included in the reviewed studies involving the orthodontic treatment of upper incisors. We concluded that movements with the Invisalign® clear aligner on the upper incisors present distinct accuracy, possibly related with movement complexity; intrusion of the incisors has low accuracy (in some cases, 0% of accuracy was reported when the tooth extruded), while incisor extrusion exhibit some of the highest accuracy values reported in the included studies (45%-142%, when the achieved movement was greater than the predicted). Besides, axial (i.e., torque and tip) and horizontal (i.e., translation and rotation) movements are usually effective, with accuracy values between 39%-156% and 42%-79%, respectively. Overall, we determined that the efficiency of aligner to reach the desired movements in the upper incisors was low, as often refinements were required in the included studies. The use of aligner features must be more often considered to improve movement accuracy.

OBJECTIVES To determine the frequency and pattern of anterior crossbite with primary and mixed dentition in School Children. METHODOLOGY A descriptive cross-sectional study was conducted at Sharif Medical and Dental College, Lahore. This study included 296 participants having either deciduous or mixed dentition, no history of orthodontic treatment, aged between 3-11 years, both genders and Pakistani nationals. Participants with a history of trauma, cleft lip/palate, or any craniofacial syndrome and systemic disease were excluded. Participant’s age, gender, skeletal class, and anterior crossbite (ACB) were recorded. The Chi-square/Fisher exact test was run to compare ACB and their pattern among gender, age group, and skeletal class. RESULTS There is a relatively high rate of anterior crossbite in this population, which is about 10%. The females were 169(57.09%) and males were 127(42.91%). The mean age was 6.92 ± 1.68 years. Overall, the ACB was present in 31(10.47%). The most common pattern of ACB was single incisor involvement (n=11, 35.48%) followed by two incisors (n=9, 29.03%), and the least was four incisors (n=5, 16.13%). The difference for ACB was statistically significant among skeletal classes (p

Objective: To investigate the CBCT findings of the apical anatomy of immature maxillary central incisors. Methods: CBCT images of 100 immature maxillary central incisors in Nolla 8 and 100 immature maxillary central incisors in Nolla 9 were collected. The mesiodistal and carniocaudal diameters of the apical foramen of immature maxillary central incisors were measured by software included with CBCT, as well as the mesiodistal, carniocaudal and facioligual diameters of the apical shadow. The apical shadow and apical foramen diameters were compared between Nolla 8 and Nolla 9. Data were analyzed using the MedCalc software package. Results: For immature maxillary central incisors, the mesiodistal and facioligual diameters of the apical foramen were 2.75±0.68 mm and 3.28±0.74 mm in Nolla 8 and 1.50±0.51 mm and 1.92±0.79 mm in Nolla 9. The mesiodistal, facioligual and carniocaudal diameters of the apical shadow were 3.84±0.73 mm, 4.49±0.68 mm and 3.41±1.27 mm in Nolla 8 and 2.76±0.60 mm, 3.41±0.80 mm and 2.06±0.65 mm in Nolla 9, respectively. Conclusions: The immature maxillary central incisors in Nolla 8 have a larger apical shadow and apical foramen than those in Nolla 9. The apical region of the maxillary central incisors in Nolla 8 was more likely to have a broad, blurred lamina dura. With the development of the apical foramen, the lamina dura in the apical region tended to be clear and sharp. Clinical significance: To our knowledge, this is the first study to radiologically analyse the in vivo anatomy of the apical foramen and apical shadow of immature maxillary central incisors. The results of this study provide a more detailed understanding of the apical anatomy of the immature maxillary central incisor for the diagnosis and treatment of apical lesions. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Impacted maxillary central incisors represent a relatively infrequent occurrence. This condition significantly impacts the patient's self‐esteem and aesthetic concerns. Effective resolution is achievable through a combined strategy involving surgical exposure, bracket attachment, and subsequent orthodontic extrusion. The Surgical orthodontic approach is the optimal strategy for addressing impacted maxillary central incisors. Central incisor is rarely impacted teeth often associated with supernumerary teeth. This case series includes three cases of central incisor impaction presented with complaints of missing teeth, unesthetic appearance, and unclear speech. All the cases were managed with surgical exposure followed by traction by orthodontic force, restoring smile aesthetics. [ABSTRACT FROM AUTHOR]

Molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM) are dental enamel developmental defects with significant prevalence and psychophysical impact, posing a public health concern. We examined the relationship between HSPM and MIH in 426 children aged 7 to 10 years (213 with MIH, 213 without MIH). The frequency of HSPM was higher in children with MIH (37.1% vs. 11.3%, p < 0.001). However, there was no correlation between MIH severity and presence of HSPM (p = 0.296). In patients with both defects (n = 79), 90% of severe MIH cases were associated with severe HSPM, while 87.8% of mild MIH cases were associated with mild HSPM (p < 0.001). The involvement of permanent incisors by MIH was not influenced by the presence of HSPM or HSPM severity. HSPM exhibited a positive predictive value of 76.7, negative predictive value of 58.8, sensitivity of 37.1% (95% CI = 30.6–43.6%), and specificity of 88.7% (95% CI = 84.5–93%). The odds ratio for MIH based on HSPM was 4.64 (95% CI). HSPM may serve as a predictor of MIH, but its absence does not rule out the occurrence of MIH. The results highlight the need for surveillance programs in children presenting with HSPM to facilitate early diagnosis and preventive measures for MIH-related complications. [ABSTRACT FROM AUTHOR]

Retrospective studies have found conflicting results regarding the relationship between lower incisor inclination and the development of gingival recession (GR) after orthodontic treatment. This study aimed to investigate the relationship between lower incisor inclination and alveolar process (AP) and mandibular symphysis (MS) thickness in the development of GR. Frontal intraoral photography and cephalometric radiography were conducted before (T0) and after (T1) orthodontic treatment of 62 subjects. The presence of GR was considered when the cementoenamel junction was visible in the lower incisor on the frontal intraoral photograph. The circumstances for improvement, stability, and worsening of the gingival situation were based on the reduction, maintenance, and increase in the number of lower incisors with GR before and after treatment. To measure the incisor-mandibular plane angle (IMPA) and the thickness of the AP and the MS were used the cephalometric radiographs. Men had a significantly thicker MS than women at T0 and T1 (p < 0.0004). There was a significant reduction of approximately 10% in AP between T0 and T1 (p < 0.0001). Among subjects without GR at T0, 70.4% presented a stable gingival situation at T1. For subjects with 1 lower incisor with GR at T0, 50% showed improvement in the gingival situation at T1, 21.4% remained stable, and 28.6% experienced worsening. Sixteen lateral incisors presented a worsening gingival situation, representing an increase of 129% compared to the central incisors. No relationship was found between lower incisor inclination and the thickness of the AP and MS in the development of GR. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the root dentinal thickness of the mandibular incisor teeth in relation with the age and sex using cone-beam computed tomography (CBCT). Methods: CBCT images of 320 mandibular incisors of 40 male and 40 female patients were analyzed retrospectively. The mesial and distal dentinal thickness was measured at three points as coronal, middle, and apical root canal thirds. The images were analyzed using a software and analyzed to investigate the differences in the dentinal thickness association between age and sex. Results: Dentinal thickness decreased significantly from coronal to the apical root canal level. The middle and apical dentinal thickness of mesial side the roots were found significantly higher than the distal side of the root. Conclusion: The coronal and apical dentinal thickness of the roots was found to be higher in males than females while the middle root dentinal thickness was found to be higher in females than males. It was found that dentinal thickness increased with age only in the coronal root region. [ABSTRACT FROM AUTHOR]

Aim: Palatogingival groove (PGG) is a morphological defect that usually affects maxillary incisors and may be related to periodontal and endodontic disease. The aim of this study was to evaluate the prevalence, characteristics, and clinical implications of the PGG in a Brazilian population. Materials and Methods: A convenience sample with 169 consecutive participants was evaluated in a crosssectional study from September 2021 to May 2022. Upper anterior teeth were evaluated by a single examiner considering the presence of PGG, its characteristics and the presence of caries, periodontal and endodontic disease. Chi-square test and logistic regression were applied and P value was set at 5%. Results: PGG prevalence was 21.67% in individuals and 5.9% in teeth. A logistic regression did not reveal significant differences between sex [female: odds radio (OR) 1 and male: OR 0.53] and race (white: OR 1; black: OR 0.81; brown: OR 0.70). The highest prevalence was found in the upper lateral incisors (68.6%), in the cingulum (80.39%), with greater occurrence in the mid-palatal face of the tooth (39.21%). A high prevalence of bleeding on probing (83.8%) and caries (37.8%) was found in teeth with PGG, but no pulp alterations were found. Conclusions: PGG prevalence is high when the number of individuals is considered, and the tooth more frequently affected by PGG is the upper lateral incisor, with greater occurrence in the mid-palatal and cingulum face. In addition to incisors, canines also can be affected by PGG. Teeth with PGG may present high rates of biofilm accumulation, periodontal inflammation, and caries. [ABSTRACT FROM AUTHOR]

Understanding cell types and mechanisms of dental growth is essential for reconstruction and engineering of teeth. Therefore, we investigated cellular composition of growing and non-growing mouse and human teeth. As a result, we report an unappreciated cellular complexity of the continuously-growing mouse incisor, which suggests a coherent model of cell dynamics enabling unarrested growth. This model relies on spatially-restricted stem, progenitor and differentiated populations in the epithelial and mesenchymal compartments underlying the coordinated expansion of two major branches of pulpal cells and diverse epithelial subtypes. Further comparisons of human and mouse teeth yield both parallelisms and differences in tissue heterogeneity and highlight the specifics behind growing and non-growing modes. Despite being similar at a coarse level, mouse and human teeth reveal molecular differences and species-specific cell subtypes suggesting possible evolutionary divergence. Overall, here we provide an atlas of human and mouse teeth with a focus on growth and differentiation.

Abstract Background Comprehensive understanding of the root canal system complexity is critical important for successful root canal therapy. A double root canal system may be present in permanent mandibular incisors with a variable incidence in different ethnic populations. Ignorance or improper management of this canal variation can lead to treatment failure. This in vitro study aimed to identify the anatomic features of root canal systems in the mandibular incisors in a Chinese population by using micro-CT. Methods A total of 106 permanent mandibular incisors (53 central incisors and 53 lateral incisors) were collected from a native Chinese population. The teeth were scanned by a micro-CT scanner and then reconstructed three-dimensionally. The canal configurations were detected by Vertucci’s classification, and the number and location of the accessory canals were also identified. The long (D) and short diameters (d) of the main and accessory canals were measured and D/d ratio was calculated at different root levels (cemento-enamel junction [CEJ] level, mid-root level and 1, 2, 3 and 4 mm from the apex). The root canal curvatures in the double-canaled mandibular incisors were measured at the proximal view by using modified Schneider’s method. Chi-square test or Fisher's exact test was used for comparison of occurrence rates. Comparison of means from multiple groups was performed by using one-way ANOVA and LSD post-hoc test. Results In regard to the occurrence of double root canals, gender difference was neither detected in the mandibular central (16.0% [male] vs 14.3% [female]; p = 0.862), nor in the mandibular lateral incisors (26.9% [male] vs 33.3% [female]; p = 0.611). Age group difference was also not detected in the mandibular central (p = 0.717) and lateral incisors (p = 0.521). The incidence of double root canals was 15.1% (8/53) in the central incisors, and 30.2% (16/53) in the lateral incisors, but the difference did not reach statistical significance (p = 0.063). The most frequent non-single canal type was the type III (1–2-1) (18.9% [20/106]), and the other types identified included 1 case of type II (2–1) and 3 cases of type V (1–2). The incidence of accessory canals was 17.9% (19/106), with a mean level of 1.92 ± 1.19 mm from the apex. The frequency of long-oval (2 ≤ D/d

Objective: The aim of this study was to determine the concordance of the vestibular bone thickness measured at the level of point A between Teleradiography and Cone Beam Computed Tomography (CBCT). Materials and Methods: This study consisted of a cross-sectional analytical design of concordance that evaluated the teleradiographies and CBCTs of 32 patients. The measurements were performed by three evaluators, specialists in orthodontics. Two of them measured the CBCTs and one evaluated the teleradiographs. The concordance of both tests was determined using the Concordance Correlation Coefficient. Results: When evaluating the value of the vestibular bone thickness at the level of point A between the CBCT and the teleradiography, it was observed that the mean value of the absolute difference between the two was 0.95±0.74, 95%CI [0.68–1.22], being statistically significant (p=0.0027). When the concordance between both tests was analyzed, it was observed that it was poor (CCC=0.204 95%CI [0.014–0.394]), although statistically significant (p

Aim: Determination of the most common shade of anterior teeth in Malaysian students of different ethnicities. Materials and Methods: A total of 120 subjects, 40 each from different ethnicities (Malay, Chinese, and Indian) aged 18-22 years were evaluated for tooth shade using the VITA Classical shade guide. The subject was asked to sit in an up-right position with teeth at the clinician’s eye level and the subject was instructed to remove makeup or tinted eyewear which may affect the result. The procedure was done in natural daylight. The shade tabs were positioned adjacent to the maxillary central incisor and the middle 1/3rd of the facial surface was assessed by experts to determine the correct tooth shade. The data was statistically analysed. Results: The differences in tooth shade were seen among the subjects of different ethnicities. The Malay ethnicity has B1 (37%) as the most common tooth shade whereas Chinese has C1 (27%) and Indian C1 (40%). Conclusions: Under the limitation of the study, it was found that there is a relationship between tooth color and ethnic background. Malay students tend to have brighter teeth as compared to Chinese and Indian students.