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Introduction: This study aimed to use cone beam computed tomography (CBCT) to evaluate the dimensional and morphological characteristics of unilaterally impacted canines, their effects on adjacent teeth, and differences with contralaterally erupted canines., Materials and Methods: A sample of 31 patients (22 males, mean age 22.22 ± 4.82 years; 9 females, mean age 23.91 ± 5.16 years) with unilaterally impacted maxillary palatal teeth were included in the study. CBCT images were obtained using a NewTom 5 G unit in standard mode. Three-dimensional multiplanar reconstructions emulating a panoramic view and curved planar reconstructions were evaluated. Individuals were divided into two groups (low- and high-complexity) according to Ericson and Kurol's impaction complexity classification., Results: The crown lengths and mesiodistal crown widths of the impacted canines were similar to the symmetric canine on the opposite arch and significantly larger than adjacent lateral and premolar teeth (p<0.05). The alpha (31.33 ± 8.32) and beta angles (39.53 ± 10.31) and the 'h' height (10.11 ± 2.02) values in the low-complexity group were significantly lower than the high-complexity group (alpha angle=57.40 ± 12.15; beta angle=71.31 ± 13.94; 'h' height=14.35 ± 3.71, and alpha angle: p<0.001; beta angle: p<0.001; 'h' height: p=0.002) CONCLUSION: The root lengths of impacted maxillary canine teeth are significantly shorter than symmetrically erupted canine teeth regarding labiolingual crown width. As the alpha and beta angles and 'h' height increase, the complexity level of the impacted canine also increases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: The objective of this study was to evaluate the risk of maxillary canine impaction through cephalometric evaluation., Methods: One hundred and eighty-two Caucasian patients (80 males and 102 females) with a mean age of 12.4±0.5 were retrospectively enrolled in the present study. Ninety patients with impacted canines were compared with ninety-two patients with physiologically erupted canines. The following cephalometric variables were analyzed: SNA, ANB, SN-GOME, GO-ME, SP-CL, SELLA TURCICA DEPHT, A-Pt LINE, B-Pt LINE, A-Pt LINE°, B-Pt LINE°, A1s-Pt, A1i-Pt, A1s-Pt°, A1i-PT°, A-SN, B-SN and SN-U1. When applicable, a paired sample t-test was performed to investigate the difference in means between the two sample groups, while the Mann-Whitney Test was used as a non-parametric test in the case of a non-normal distribution of data. Statistical significance was set at P<0.05., Results: The group with impacted canines showed an increase in Go-Me distance, SNA angle and A1s-Pt angle compared with the control group. In addition, the same group showed a decrease in A-SN and SP-Cl distance compared with the control group., Conclusions: An increase in mandibular length (GO-ME) and SNA angle associated with a reduction in A-Sn distance and interclinoid distance (SP-Cl) were observed in patients with impacted canines.

Reports on the histopathologic features of external cervical resorption (ECR) in unerupted teeth are scarce. This article reports on 2 maxillary impacted canines from different patients that showed ECR lesions and were surgically removed and histologically evaluated. Case 1 showed symptoms associated with oral communication of the dental follicle and pulpal exposure. Radiographs and cone-beam computed tomographic imaging showed that resorption affected a large part of the root and the crown. Case 2 was asymptomatic, and the resorption cavity was restricted to the tooth crown. Both teeth were extracted and subjected to histologic processing and analysis. In case number 1, the coronal pulp was necrotic and infected, showing areas of exposure to the resorption channels. The apical pulp was vital and uninflamed. The pulp space was surrounded by a continuous pericanalar resorption-resistant sheet. Part of the resorbed area of dentin was occupied by inflamed granulation tissue. More apically, a network of trabecular bone was present in the resorbed area. In case number 2, the pulp around the resorbed area was uninflamed and vital. A large fraction of the lost dentin was replaced by trabecular bone, closely adapted to the irregularly resorbed dentin surface, and no inflammatory cells. Our findings indicate that impacted teeth with ECR may remain asymptomatic until associated with infection. Histologic features of resorption in impacted teeth were similar to those in erupted teeth. In the case associated with infection, the resorbed area was occupied by inflamed tissue and newly formed bone. In the case with no infection, the resorption area was filled with bone undergoing a remodeling process., (Copyright © 2023 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: We aimed to comprehensively examine how the anatomic characteristics of asymptomatic third molars (As-M3s) affect distal pathologies of adjacent second molars (Ad-M2s)., Materials and Methods: Patients with at least 1 quadrant having intact As-M3s and first and second molars were enrolled. Distal pathologies of Ad-M2s, including caries, pocket depth of 4 mm or more (PD4+), and alveolar bone loss of 3 mm or more (ABL3+), were analysed based on As-M3 status (absent/impacted/nonimpacted). Especially within nonimpacted M3s (N-M3s), the effects of regions (maxillary vs mandibular) and dental intervals (narrow vs wide) on Ad-M2 pathologies were further compared., Results: A total of 248 patients with their 805 quadrants were finally included in this cross-sectional study. The impacted and nonimpacted As-M3s elevated the risk of any distal pathology (caries, PD4+, or ABL3+) of Ad-M2s vs M3 absence with odds ratios (ORs) of 8.33 and 3.27, respectively. Within N-M3s, mandibular regions increased the odds of PD4+ (OR, 1.96); wide dental intervals increased the odds of ABL3+ (OR, 3.01). However, maxillary regions and narrow dental intervals contributed to more severe bone loss in Ad-M2s with ABL3+., Conclusions: The presence of As-M3 is a risk factor for Ad-M2 pathologies irrespective of impaction status. Within N-M3s, Ad-M2 pathologies are significantly influenced by anatomic characteristics such as regions and dental intervals., Competing Interests: Conflict of interest None disclosed., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: This paper aims to better define hypercementosis, investigate its described potential aetiologies, and determine whether there are different patterns of cementum apposition and if they are a function of their supposed aetiology., Design: A literature review was undertaken using the Medline, DOSS, Scopus and Cochrane Library electronic databases. Two co-authors selected the published works independently, extracted the data in accordance with the PRISMA statement., Results: Among 546 articles, 75 articles were finally selected. Eight different supposed aetiologies were identified: (1) intensive masticatory effort, (2) systemic disease, (3) carious lesion and apical periodontitis, (4) impaction, (5) periodontal disease, (6) concrescence, (7) super-eruption, and (8) drugs. Some of these aetiologies can be combined in the same tooth. Hypercementosis manifestations are various in nature and extent with different patterns that may be aetiology-specific. To improve the description and associated consistency in the characterisation of hypercementosis, in this review but also in future studies, we propose a new qualitative scoring system to quickly characterise hypercementosis and determine its most relevant aetiology., Conclusions: This systematic review demonstrates that hypercementosis is a complex and not yet well-defined condition. Some forms of apposition are specific to a given aetiology. The hypercementosis characterisation may contribute to document the oral condition and/or the individuals masticatory activity., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: The indication for removal of asymptomatic fully impacted third molars is still controversial. In this study, radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars was performed, aiming to provide a reference for clinical prophylactic extraction of these teeth., Methods: Patients with impacted mandibular third molars were included and the maximum width of the dental follicle around the crown was measured in horizontal, sagittal and coronal sections by cone beam computed tomography. The dental follicles were stained with haematoxylin-eosin, analysed by a pathologist and classified as normal, inflammatory or cystic. A Chi-squared test was used to analyse the association of the incidence of inflammation and cysts with the clinical variables of the impacted mandibular third molars., Results: Thirty-seven samples were normal dental follicles; 52 samples showed inflammatory infiltration with an incidence of 57.14%; 2 samples with a maximum dental follicle width of 2-3 mm were diagnosed as odontogenic cysts, and the incidence was 2.20%. There was no significant difference in the incidence of inflammatory and cystic dental follicles between males and females, or between different age groups (P > 0.05). With an increase of the maximum width of the dental follicle, there was a rise in the incidence and degree of infiltration of chronic nonspecific inflammation., Conclusion: Asymptomatic impacted mandibular third molars tend to be extracted, especially for teeth with a 2-3 mm maximum width of the dental follicle on radiological examination., (© 2022. The Author(s).)

Background: A correlation between impacted maxillary third molars on the eruption potential of the maxillary second molar has been identified. There is little published evidence available in the literature regarding a treatment modality for this presentation. AIMS  : The aim of this case series is to propose a joint surgical and orthodontic approach for the management of such cases. METHOD  : A retrospective search of all patients treated for impacted second and third maxillary molars from 2014 to 2020 revealed 24 cases. Surgical planning was facilitated with the use of a CBCT to help orientate the teeth in 3-D and assess any associated pathology to nearby structures. Twenty-three cases were treated via surgical removal of the impacted third molar and subsequently monitored for spontaneous maxillary second molar eruption., Conclusion:  All treated cases showed complete or partial spontaneous eruption followed by orthodontic repositioning if required., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic tumor. It is characterized by showing, on histopathological examination, clusters of vacuolated and clear tumor cells with epithelial differentiation surrounded by fibrocollagenous stroma and fibroblasts. The present study presents a rare clinical case of mandibular CCOC associated with an impacted tooth in a 26-year-old woman surgically treated with mandibulectomy and reconstruction with iliac crest bone graft. The patient has been followed up for 22 months without signs of recurrence. A search for case report/case series was carried out in the PUBMED database, as well as in the references of relevant previously published literature reviews. Ninety-six publications were identified, totaling 136 distinct cases reported. Female sex was the most affected (63.1%) with 63.3% of cases occurring in patients in the fifth, sixth, or seventh decades of life. The mandible was more affected than the maxilla (74.2%). Association of CCOC with impacted teeth was found in 2.4% of cases, thus rendering it a rare occurrence. The present case report corroborates the results of the survey regarding sex and anatomical location of the tumor; however, it contradicts the findings regarding age predilection. The case described is the fourth known occurrence of tooth impaction associated with the tumor and the first in a female. In conclusion, CCOC should be considered, as well as other malignancies, as a possible diagnosis of maxillary or mandibular intraosseous lesions even in unusual circumstances such as in association with impacted teeth and in young patients., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To examine the diagnostic value of orthopantomograms (OPG) in the identification of root resorption of lateral incisors, secondary to an impacted canine, as confirmed by a cone-beam computed tomography (CBCT) scan., Design: Retrospective observational cohort study., Setting: South Wales secondary care setting: Royal Gwent Hospital, Newport and Nevill Hall Hospital, Abergavenny., Methods: A total of 40 consecutive patients with impacted canines between January 2018 and December 2019 were selected. For each patient, one consultant orthodontist examined the OPG in isolation to detect the presence and extent of resorption of lateral incisors. The CBCT report was then studied to confirm the presence and extent of pathology. Sensitivity, specificity, accuracy, positive predictive values and negative predictive values were calculated., Results: In total, 19 maxillary right canines, 18 maxillary left canines, one mandibular right canine and two mandibular left canines were examined. Impactions were more prevalent in the maxilla (92.5%) with higher predilection towards female patients (65%). There was higher prevalence of root resorption in the maxillary right quadrant (57.1%), in concordance with other studies. OPGs were found to have a sensitivity of 81.0% and a specificity of 10.5%, with an accuracy value of 47.5%. Positive and negative predictive values were found to be 50.0% and 33.3%, respectively. The extent of root resorption was incorrectly estimated from the OPG in 84% of cases. Correct estimation occurred in 16% of cases, with overestimation and underestimation occurring in equal proportion (42%)., Conclusion: This study demonstrates the limitations of plain film radiographs and the merits of using CBCT in the accurate diagnosis of resorption of lateral incisors with an associated impacted canine. It also gives an indication into the location prevalence of resorption in a small cohort of patients. This preliminary study establishes the basis for future, larger-scale studies where outcomes can be generalisable at a population level.

Objective: To estimate the mean prevalence of periodontal pathology of adjacent second molars (A-M2s) to third molars (M3s) and identify related confounding factors., Methods: Studies published before August 2020 were systematically searched in the Cochrane Library, EMBASE and MEDLINE databases. We included cross-sectional studies that evaluated the periodontal pathology of A-M2s based on clinical or radiographic examinations at the molar level. Studies employing similar periodontal parameters were pooled. Clinical attachment loss ≥ 3 mm, alveolar bone loss ≥ 3 mm or ≥ 20% root length were defined as early periodontal defects, and at least one site with probing depth ≥ 5 mm was considered as deep periodontal pockets around A-M2s in the data synthesis., Results: Nine studies (14,749 M3s) were ultimately included in the meta-analysis. On average, 19% of A-M2s showed distal early periodontal defects with the presence of M3s (95% confidence interval [95% CI] 9%-35%). Subgroup analyses suggested the prevalence was 32% (95% CI 16%-54%) in the mandible, and the prevalence was higher with nonimpacted M3s (25%, 95% CI 12%-47%) than with impacted M3s (19%, 95% CI 10%-35%). Additionally, the pooled prevalence for deep periodontal pockets around A-M2s was 52% (95% CI 39%-64%). Subgroup analyses suggested the prevalence was higher in the mandible (62%, 95% CI 45%-76%) than in the maxilla (43%, 95% CI 31%-56%), and for nonimpacted M3s the prevalence reached 50% (95% CI 36%-64%)., Conclusion: The presence of M3s, especially mandibular and nonimpacted M3s, negatively affects the periodontal status of A-M2s.

The objective of this study was to study the incidence of type of impaction of mandibular third molars based on the classifications of Pell and Gregory and Winter, which included angulation of the tooth and level of the occlusal surface of the third molar with respect to the second molar, respectively, in a sample of Saudi population in central region. In this retrospective study, orthopantomograms (OPGs) of 17760 patients were examined, who were reported by the Dental University Hospital (DUH) at King Saud University, Riyadh, Saudi Arabia, between the years 2016 and 2020. Out of 17760 radiographs, 2187 (12.31%) patients presented with at least one impacted third molar. Out of which, 1337 (7.52%) patients had bilateral impaction and 850 (4.78%) patients had unilateral impaction ( p < 0.001). No gender predominance was noted in the impaction status ( p > 0.05). In bilateral impaction, 671 were male (50.2%) and 666 were female (49.8%). Among unilateral impaction, 394 (46.4%) were male and 456 (53.6%) were female. Mesioangular angulation was the most common pattern of impaction (65%) followed by vertical angulation in both bilateral and unilateral impactions. Level A impaction was found to be highest in both bilateral and unilateral impactions which are 48.02% and 54.0%, respectively ( p < 0.05). Our study highlights mesioangular impaction and level "A" as the most frequently encountered angulation and level of impaction in impacted teeth. This study result provides us useful data regarding the radiographic status of mandibular third molars in the population of Saudi Arabia., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Mahmud Uz Zaman et al.)

The aim of this study was to evaluate the levels of vitamin D (25OHD) and other bone biomarkers in patients with third molar impaction (TMI). Thirty males and 30 females with unilateral or bilateral impacted mandibular third molar, and 15 males and 15 females as a control group (CG) were recruited. Rx-OPT was used to evaluate dental position and Pederson index to measure the difficulty of the intervention. Bone biomarkers were measured through blood venous sample in TMI group and CG. Mann-Whitney test, Pearson's correlation coefficient, linear regression model were used to compare the different parameters in the two groups. 25OHD showed lower values in TMI group than in CG ( p < 0.05) with values significantly lower in bilateral impaction ( p < 0.05). Pearson's coefficient for 25OHD presented a negative correlation with the Pederson index (ρ = -0.75). Bone alkaline phosphatase (BALP) showed significantly lower dosage in TMI group than CG ( p = 0.02), Pearson's coefficient for BALP presented a negative correlation with the Pederson index. Serum calcium, serum phosphorus, ionized calcium levels in TMI and CG groups were similar and Mann-Whitney test did not significantly differ between TMI and CG. TMI could be a sign of vitamin D deficiency and of low BALP levels that should be investigated.

To evaluate the associations of impaction patterns of mandibular third molars (M3Ms) with pathologies caused by them. In this study, 262 patients with 432 impacted M3Ms who referred in Shanghai Xuhui District Center were reviewed. The pathologies include pericoronitis, mandibular second molar (M2M) caries, and M2M distal periodontal pathology. The impaction patterns of M3Ms and the pathologies were examined, while the M2M outcomes after surgeries were evaluated. A χ 2 test was used to analyze the data, with a p value of <0.05 being considered statistically significant. Pericoronitis was the major symptom in all patients, whereas the propensities of M2M distal caries and periodontal pathologies increased in older patients. Soft tissue impacted and vertically angulated teeth were more associated with pericoronitis ( p  < 0.05); mesio-angular impacted teeth in less deep positions had greater risks of M2Ms distal caries ( p  < 0.05); mesio-angular and horizontal impacted teeth in relative deep positions were more likely to cause M2Ms distal periodontal pathologies ( p  < 0.05). Extractions of soft tissue impacted teeth in vertical angulations should be considered, while removals of mesially and horizontally angulated or bony impacted teeth could be delayed.

Odontogenic cysts are categorized as inflammatory and developmental. Of the developmental odontogenic cysts, the dentigerous cyst is the most common and by definition is attached to the cervical region of an unerupted tooth. The cyst envelops the crown forming a sac. However, there are other developmental cysts, and rarely, odontogenic tumors, that can have a similar clinical and radiographic presentation as dentigerous cyst, including odontogenic keratocyst, orthokeratinized odontogenic cyst and ameloblastoma, unicystic type. Understanding the key histologic differences of these cysts will aid the pathologist to correctly diagnose these lesions, ensuring appropriate clinical management.

Background: Pericoronitis is a painful inflammatory condition commonly associated with third molar teeth. The purpose of this study was to investigate the relationship between oral hygiene and periodontal health status and the presence of pericoronitis in semi-impacted third molar teeth., Methods: A cross-sectional study was conducted, and 54 patients having at least one mandibular vertically semi-impacted third molar tooth with or without pericoronitis were consecutively enrolled. Subjects with pericoronitis and subjects with healthy third molars were selected according to symptoms in the gingiva overlying semi-impacted third molar teeth. Periodontal health status and oral hygiene were evaluated with the measures of plaque index (PI), gingival index (GI), and total number of sites with a probing depth (PD) ≥ 4 mm. The clinical data collected in this study was analyzed with Mann-Whitney U test using SPSS 20.0 package program., Results: The PI scores were found to be significantly higher in patients with pericoronitis ( p < 0.05). Although the GI scores and PD scores were higher in patients with pericoronitis, the difference did not reach statistical significance when compared with those in healthy subjects ( p > 0.05)., Conclusion: The findings obtained in this study suggest that the amount of dental plaque was positively associated with third molar pericoronitis. Gingival and periodontal health conditions were similar between patients with and without pericoronitis. Improving oral hygiene and controlling dental plaque may help prevent third molar pericoronitis., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2021 Mehmet Gagari Caymaz and Oğuz Buhara.)

Purpose: To compare the buccal alveolar bone thickness of mesioangulated mandibular impacted third molars (MITM) with buccal versus lingual inclination using cone-beam computed tomography (CBCT)., Methods: This retrospective cross-sectional study evaluated 69 individuals (39 women and 30 men) who presented a total of 101 mesioangulated MITM according to the Winter classification and in B position according to the Pell and Gregory classification. The average age was 22.99 ± 3.94 years. The superior, medial and inferior alveolar thickness regarding buccal (n = 44) or lingual (n = 57) mandibular third molar inclination were measured. T test or Mann-Whitney U test and finally, a multiple linear regression were applied (p < 0.05)., Results: The buccal alveolar bone thickness of mesioangulated mandibular impacted third molars was significantly greater in the group with lingual inclination compared to the group with buccal inclination, in the superior region (6.21 ± 3.27 vs. 4.85 ± 3.06; p = 0.036). The lingual inclination significantly influenced the buccal alveolar bone thickness in the middle region (p = 0.011)., Conclusions: The mesioangulated MITM in B position with lingual inclination have a greater thickness of the superior and medial buccal alveolar bone than the MITM with buccal inclination. These results should be considered during MITM diagnosis and surgical planning.

Objective: Maxillary canine impaction is directly associated with a narrow maxillary arch, mainly in the inter-premolar widths. This study compared the transverse changes at the level of maxillary premolars after traction of maxillary impacted canines (MICs) in adolescents and young adults through three main goals: to compare unilateral versus bilateral cases, to compare buccally versus palatally MIC cases, and to compare the affected versus non-affected side exclusively in the unilateral group., Methods: This before and after CBCT study involved 45 MIC orthodontically tractioned until the occlusal plane with a standardized protocol. The sample was classified regarding the impaction type (unilateral versus bilateral), impaction location (palatal versus buccal) and the affected versus unaffected sides in the unilateral cases. MIC characteristics as impaction sector, height, and complexity of the traction, as well as α and β angles, canine root length and area were measured. Moreover, cephalometric characteristics were also evaluated. Mann-Whitney U or Wilcoxon signed-rank tests and multiple regressions were applied (α=0.05)., Results: Maxillary inter-premolar widths (first or second) expanded approximately 3mm after traction of unilateral or bilateral MIC (P>0.05). Changes in hemi-arch widths between palatal (1.67mm) versus buccal (1.90mm) MIC were similar (P>0.05). In unilateral impaction, the transversal changes on the affected side were 2mm versus almost 1mm observed in the unaffected side (P<0.05). Finally, the multiple linear regressions were identified to the ANB angle, the impaction sectors and the distance from middle raphe to the cusp tip of MIC as influential variables., Conclusion: The maxillary inter-premolar widths increase after traction of MIC without differences between type or location of impaction. In addition, the transverse change in the affected side in unilateral MIC is greater than the unaffected side resolving the earlier transverse asymmetry., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Objective: Maxillary impacted canines (MIC) could suffer root changes after canine traction. The aim of this study was to evaluate the 3-dimensional root changes in buccal versus palatal MIC after orthodontic traction., Materials and Methods: This longitudinal and retrospective study included pre-treatment and after traction cone beam computed tomography scans (CBCTs) of 30 subjects with unilateral/bilateral MIC. A total of 43 MIC were divided into 2 groups: buccal (n=17) or palatal (n=26). Root changes in length and area after orthodontic traction were measured at sagittal, coronal and axial sections. Intergroup comparison was carried out by t or U Mann-Whitney tests, depending on normality. Multiple linear regression analysis was used to evaluate the influence of all predictor variables on root changes (P<0.05)., Results: Significant difference between groups was found for root area changes in the upper limit of the cervical third at axial section that showed greater appositional values for the palatal impacted canine group (-1.18mm 2 ) and resorptive values for the buccal impacted canine group (0.62mm 2 ) (P=0.024). Position of impaction palatal influenced the increase of root area in the coronal section and in the upper limit of the cervical third at axial section. Age directly influenced the decrease of total length and root area in sagittal and coronal sections, respectively., Conclusion: Orthodontic traction of MIC produced an important appositional root change in the palatal impaction group in the axial root area of the upper limit of the cervical third. Impaction position and age influenced the increase and decrease of root area and length of some specific radicular regions., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Background: Pericoronal radiolucent lesions are a common radiographic finding, but it is rare that they occur in multiple forms. Multiple calcifying hyperplastic dental follicles (MCHDF) are entities with few cases described to date; nevertheless, they appear to have a very particular phenotypic pattern., Cases Presentation: Case 1: A 10-year-old male was evaluated radiographically, revealing four impacted canines, each accompanied by unilocular pericoronal radiolucency. Case 2: A 16-year-old male was planning orthodontic treatment; following his radiological evaluation all third molars were found to be accompanied with pericoronal radiolucencies. Enucleation, and third molar removal along with the pericoronal tissue were the respective treatments. Microscopically, in both cases, the specimens shown odontogenic epithelium, and type I and II calcifications in the hyperplastic follicles, all these characteristics were consistent with MCHDF., Conclusion: Although MCHDF are a rare entity, they must be considered in the differential diagnosis of multiple pericoronal lesions. Under the light of the current evidence, the histological findings may be relatively heterogeneous, but their integration with both the clinical data, which are apparently particular, and with the radiographic characteristics, can lead to a definitive diagnosis.

Objectives: The aim of this study is to determine the type, frequency, and location of incidental findings in the maxillofacial region in patients undergoing cone beam computed tomography (CBCT) scan for implant treatment. [5] ., Methods: In this study, 300 patients who underwent CBCT imaging for implant treatment planning were evaluated retrospectively. Patients were evaluated in four different categories, namely, maxillary sinus pathologies, temporomandibular joint (TMJ) findings, dentoalveolar findings, and soft-tissue calcifications. In maxillary sinus pathologies, we categorized patients by mucosal thickening, polypoidal lesion, air-liquid level, total opacification, oroantral fistula, periapical lesion related with maxillary sinus, antrolith, hypoplasia, and foreign body presence. In the TMJ findings category, we evaluated patients for erosion, osteophyte, sclerosis, flattening, and bifid condyle. For dentoalveolar findings, we looked for the residual root and impacted tooth. In soft-tissue calcifications, we examined patients for tonsillolith, sialolith, lymph node calcification, styloid ligament calcification, carotid artery calcifications, and osteoma cutis., Results: Mucosal thickening was mostly seen in maxillary sinus pathology. One hundred and forty-eight (49.3%) of the patients had at least one TMJ incidental finding. We detected at least one impacted tooth in 17 (5.7%) patients' maxilla and 14 (4.7%) patients' mandibles. The most frequently seen calcification was styloid ligament calcification. There was no statistically significant relationship between the age groups and incidental findings (P > 0.05)., Conclusions: Oral radiologists should be aware of incidental findings and evaluate the possibilities of underlying diseases in a comprehensive way, and if there is a concern about the finding, they should refer the patient to the relevant specialist., Competing Interests: None

Background: The aim of the study was to evaluate the sella and craniofacial morphological features in growing patients with palatally displaced canines compared to controls., Materials and Methods: Twenty-two subjects with palatally displaced canines were retrospectively selected and compared to 22 controls matched for age and gender. Lateral cephalograms were collected and sagittal and vertical cephalometric variables were measured, together with sella interclinoid distance, sella depth, and sella diameter. The independent samples T-test or Mann-Whitney U-test were used to compare all the variables between the two groups. A Pearson correlation was computed for the craniofacial and sella variables that differed significantly (p < 0.05) between the groups., Results: Patients with palatally displaced canines showed a smaller interclinoid distance and a greater SNA angle than control subjects. The interclinoid distance and the SNA angle were negatively correlated (-0.52, p = 0.017) in the experimental group., Conclusions: Growing patients with palatally displaced canines had smaller sella interclinoid distances and a greater SNA angle than control subjects.

Mandibular third molar teeth have the highest impaction frequency for several reasons such as lack of space which may be related to the direction of facial growth. Gonial angle is used for the definition of facial growth pattern with some other measures such as mandibular plane angle. Winter and Pell-Gregory classifications are used for defining the level and pattern of mandibular third molar impaction. The aim of this study is to define the relationship between mandibular third molar impaction pattern and gonial angle; also to evaluate relationship between mandibular third molar roots and inferior alveolar canal. Study included 90 patients who had undergone cone beam computed tomography assessment for mandibular third molar impaction. Impacted teeth were grouped according to Pell-Gregory depth (A, B, C) and ramus (1, 2, 3) classification and sub-groups were composed. Winter classification was used for angulation of third molars and their relationship between with inferior alveolar canal was recorded. Gonial angle was measured on panoramic radiographs. Of the evaluated 90 impacted third molars, mesioangular position was the most frequent (34.4%), followed by vertical, horizontal and distoangular positions. Nearly 77% of the impacted third molar roots were related to inferior alveolar canal. While no correlation was determined between gender, age, third molar angulation and gonial angle, C2 sub-group of Pell-Gregory classification showed statistically significant higher gonial angle values. Although no significance was found, gonial angle was higher in level C group. In conclusion, gonial angle is higher in patients with C2 impaction level. Also, although statistically insignificant, Pell-Gregory C group had higher gonial angle averages.

The aim of this work was to analyse the intraosseous position of the maxillary canine in orthodontic patients. It was an exploratory pilot study prior to the next research work to develop a predictive model based on a regression analysis initially including a large number of variables. 105 subjects from 6 to 12 years from both genders were included in this study. Four variables were used. The study showed that there was no marked gender dimorphism concerning the intrabony position of the canine; the latter is quite similar on both sides, and the older the age, the smaller the angulation of the canine. The values obtained for the angulation of the canine, its depth of impaction, its position in relation to the lateral incisor and the premolars, correspond to an average impaction severity and treatment difficulties., (Copyright © 2019. Published by Elsevier Masson SAS.)

Aim: The etiology of teeth impaction is still not fully understood, despite that cofactors have been considered important to develop such a clinical picture. The aim of the authors' paper was to investigate about facial biotype, about the values of inclination of the upper cuspid axis to the perpendicular to Frankfort-horizontal plane and about the distance "d" of the canine cuspid to occlusal plane: each factor was statistically compared. The authors also performed a comparative analysis on the radicular length of the left and right lateral incisors of subjects with impacted maxillary canine., Methods: The authors recruited with "cluster sampling" randomization more than 30 patients, then refined to 25 after the application of exclusion criteria. Specific values were carried out by x-rays: the authors calculated both the α and β angles, the intermaxillary angle, the distance "d" and the inclination of upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane. Spearman rank correlation coefficient or Spearman rho (ρ) was used as statistical methods., Results: The authors' results assessed that the inclination of the upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane showed a statistically significant inverse correlation with the intermaxillary angle., Conclusion: The authors' data clearly indicate that hyperdivergence is a key-factor that will certainly support the eruption path of canine cuspid: in this light, the treatment of tooth impaction in hyperdivergent subjects can be considered as predictive for a good prognosis.

Objectives: The aim of this study was to investigate the possible relationship between the morphology of maxilla and the palatally displaced canines (PDC)., Materials and Methods: In this cross-sectional study, there were 101 patients (45 males, 56 females) aged 12 to 16years, referred to Hamadan school of dentistry in 2014. They were divided into 3 groups: the bilateral PDC (PDCb) group (male=15, female=21), the unilateral PDC (PDCu) group (male=16, female=19), and the control group (male=14, female=16). Five morphology related variables including intermolar width, maxillary arch length, palatal vault depth, palatal intermolar area, and nasal width were measured using CBCT images with Dolphin Imaging software, version 11.5. Statistical analysis was performed with ANOVA and the Dunnett test using SPSS software, version 16.0., Results: Only the palatal intermolar area and the palatal vault depth values were significantly less in the PDCu and the PDCb groups than those in the control group (the palatal intermolar area: 376.17, 381.93, and 423.75mm 2 , the palatal vault depth: 13.19, 13.42, and 14.59mm; respectively; P<0.05). For all the variables, there was no statistically significant difference between the PDCu and PDCb groups., Conclusion: Decreased palatal vault depth and palatal intermolar area may be correlated with greater chance of palatal displacement of canines. Future prospective studies in mixed dentition patients are needed as a predictive factor to find the probability of PDC., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Objective: The aim of this paper was to analyse the dental remains of an adult male with three impacted canines from the Roman period cemetery in Osijek, Croatia., Materials: The dental remains of an adult male aged 35-45 years at the time of death were analysed., Methods: Macroscopic analysis of dental remains was accompanied by radiographic examination., Results: The individual also had additional dental pathologies (carious lesion, antemortem tooth loss). A total of 21 permanent teeth were present in maxillae and mandible. Eighteen of them were normal fully erupted dentition, while three were impacted: left maxillary canine and both mandibular canines. The left maxillary and mandibular canines were mesially inclined, and the right mandibular canine was relatively horizontally positioned., Conclusion: A case of non-syndrome impaction in which the lack of eruptive force in combination with the unfavorable position of the tooth bud might have resulted in multiple impacted teeth is presented., Significance: Current clinical knowledge reports low frequency of this anomaly, with maxillary impaction occurring more often than mandibular. Furthermore, canine impaction is even more rarely reported in the archaeological material. The presented case is the only one from the archaeological setting with impaction present both in maxillae and mandible., Limitations: In modern populations multiple impactions are often associated with various syndromes. Since the majority of syndromes affect soft tissue, their association with impaction cannot be confirmed in archaeological populations., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Our purpose was to investigate the relationship between the angulation of mandibular third molars and the thickness of the lingual bone, which can affect the risk of lingual nerve damage during lower third molars surgical extraction., Material and Methods: This study consisted of 104 patients (42 males and 62 females), aged between 18-42 years (24.67 ± 6.11 years). Cone Beam Computed Tomography (CBCT) images were taken for preoperative assessment. The teeth were divided into four groups according to their positions: mesioangular, distoangular, vertical and horizontal. Lingual bone thickness around impacted teeth were measured at three points: cementoenamel junction (CEJ) of the mandibular second molar, mid-root of the impacted third molar, and apex of the impacted third molar root. Two predisposing factors of lingual nerve damage were recorded: lingual bone perforated by the impacted tooth and lingual bone thinner than 1 mm. Additionally, buccolingual angulations of the teeth in each group were measured. Impacted mandibular third molars were removed in usual way. One week after surgery, the patients were evaluated regarding lingual nerve paresthesia., Results: None of the 104 patients experienced paresthesia, including the ones who had teeth with close proximity with lingual nerve. The mean thickness of bone was 1.21±0.63 mm at CEJ of the second molar; 1.25±1.02 mm at the mid-root; and 1.06±1.31 mm at the apex. Horizontally impacted teeth had thinner lingual bone at mid-root level (p=0.016). Buccolingual angulated teeth were more often associated with perforated lingual bone (p=0.002). Buccolingual and mesial/distal angulation had negative correlation with lingual bone thickness (p<0.05)., Conclusions: As the buccolingual and mesiodistal angulations increase, lingual bone thickness decreases. Horizontally impacted teeth seemed to compromise the integrity of the lingual bone more than impacted teeth in other positions. During the surgery, thin or perforated lingual bone may result in displacement of the impacted tooth lingually.

A male patient about 45 years old came to my private clinic "The Dental Aid", Dhanmondi, Dhaka, Bangladesh last year (February 2016) with the complaint of pain at right palatal premolar region. On clinical examination we found the absence of upper left 2nd premolar from the series of dentition but on the right side premolars are present. The oral mucosa was intact and normal in color. There was no caries, dental pocket or any other pathology in the teeth of both jaws. On palpation we found soft area on the right palatal side at the premolar area. We took intraoral peri-apical radiograph and found impacted left 2nd premolar whose crown was encircled by radiolucent area at the palatal side. Here, we present a rare case of transmigrated and impacted left 2nd maxillary premolar associated with dentigerous cyst. The cyst was successfully treated under general anaesthesia by enucleation along with extraction of the involved maxillary transposed and impacted left second premolar.

Background: An impacted tooth is one of the most commonly occurring dental anomalies, although some types of impaction (i.e. inverted angulation) may be considered rare finding. There are many hypotheses regarding impaction aetiology. One of the most popular hypotheses suggested that this condition may result from insufficient space in retromolar space, other: improper angulation of tooth bud, malposition of the tooth germ or hereditary factors, insufficient interproximal attrition, ectopy or dysfunction of genes necessary for proper tooth eruption. This study aims to present the odontological and paleopathological assessment of the impacted molars observed within the skull excavated from an early modern cemetery in Wroclaw., Materials and Methods: The skull used in the study was complete and in a good state of preservation. It belonged to an adult individual whose body was buried at the former Salvator Cemetery (currently Czysty Square). The individual's dentition was almost completely lost antemortem. Only second molars preserved within the maxillae (bilaterally) and the mandible was almost edentulous as well. The morphometric traits have been taken according to standards established by R. Martin. Macroscopic observations were supported by X-rays and computed tomography imaging., Results: The age at death was estimated at 20-35 years. Comparison of the metric characteristics of skull with the reference material reveals that it is much smaller than the average female skull from this series. Morphometric indices calculated for both splanchocranium and neurocranium allow defining the skull and jaw as short, which could be an important factor involved in the teeth impaction., Conclusions: Atypical impaction of the third molars could result from small size of skull and could have significantly deteriorated the quality of life of the individual.

Our aim was to assess the association between the angle of impaction of the third molar and the position of the mandibular canal on cone-beam computed tomography (CT). We designed a retrospective study of 100 cone-beam CT images of 173 mandibular third molars that were obtained between January 2012 and December 2015, and recorded the angle of impaction of the third molar, the position of the mandibular canal in relation to the impacted tooth, and the potential contact between the roots of the tooth and the mandibular canal. Most third molars tilted mesially (n=33), while the mandibular canal was positioned below the roots of the third molar in most cases (n=73). Contact between the two was most likely when the mandibular canal was between (RR=1.49; 95% CI 1.27 to 1.75, p<0.001), or to the lingual side (RR=1.49; 95% CI 1.27 to 1.75, p<0.001) of the roots of the tooth. These outcomes indicate a greater likelihood of contact between the canal and the roots when the canal is between, and to the lingual side, of the roots. We found no association between the angle of impaction and the position of the canal. These findings illustrate the importance of surgical planning using complementary imaging tests such as cone-beam CT., (Copyright © 2018 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the association between maxillary dental arch transverse dimensions, palatal depths, palatal area and volume with buccally displaced canine (BDC) in mixed dentition subjects when compared to non-BDC subjects using laser scanner 3D technology., Materials and Methods: Sixty Caucasian subjects, 8-11 years of age (mean, 9.26 ± 1.48 years), were included. In each group (BDC and non-BDC) 30 children were matched. Digital dental casts were obtained using a 3 Shape D700 laser scanner. Intercanine and intermolar widths (cusp and gingival levels), anterior and posterior palatal depth (cusp level), palatal surface area and volume were measured. An independent sample Student's t-test and an ANOVA were undertaken with significance level set as P < 0.05., Results: Intercanine widths at the cusp (1.76 mm; P = 0.020) and the gingival level (1.6 mm; P = 0.006), palatal area (133 mm2; P = 0.021) and volume (790 mm3; P = 0.046) were significantly lower in the BDC compared to the control group., Limitations: A smaller part of the subjects was in late mixed dentition phase. To overcome this limitation a matched control group was used. Some subjects did not have some teeth because of the transition phase which might have had an influence on the dental measurements. However, these subjects were not excluded to avoid introducing a bias., Conclusions: 3D evaluation of the maxillary arch and palate highlighted significant differences between BDC and non-BDC mixed dentition subjects. Maxillary dental arch dimensions and palate morphology may allow early identification and prevention of maxillary canine impaction.

Objectives: To compare parameters related to impacted canines at the cleft versus the normal contralateral side and with non-impacted canines at the cleft side in unilateral cleft lip and palate (UCLP) patients. We also aim to search for possible associated parameters enabling prediction of canine impaction in these patients., Materials and Methods: Ninety-five non-syndromic UCLP patients were included and divided into group A (n = 41 patients) with unilateral impacted canines at the cleft side (A1) and spontaneously erupted canines at the non-cleft side (A2) and group B with spontaneously erupted canines at the cleft side (n = 54 patients). Clinical information and radiographic parameters on panoramic radiographs were collected and compared between groups using a generalized linear mixed model, a Mann-Whitney U-test, a Fisher's exact test, and receiver operating characteristic tests., Results: Impaction of the maxillary canine at the cleft side in UCLP patients can be suspected in case of delayed canine root development, a higher vertical position and sector score (P < 0.05) and higher angles between the canine and the midline, as well as between canine and lateral incisor and between first premolar (P < 0.001). Results clearly indicate that the erupting canine position at the cleft side, even when not impacted, is different from the non-cleft side., Conclusion: There is a great risk for canine impaction at the cleft side in UCLP patients when the canine position is more apical than one-third of the root of the adjacent lateral incisor and when the angles between canine and midline and between canine and first premolar are higher than 23.82 and 16.1 degrees, respectively. These associated parameters should have to be studied in a prospective setting to confirm their predictive value.

Background: The aim of this study was to investigate the association between the severity of permanent tooth impaction and a number of predefined factors, including tooth type, age, gender, tooth agenesis, microdontia of maxillary lateral incisor, and retained deciduous predecessors., Methods: A sample of 2979 dental patients, aged 15 to 40 years, was surveyed by two calibrated examiners for permanent tooth impaction (excluding third molars). On panoramic radiographs, the impacted teeth were initially ranked based on their vertical, horizontal, and angular positions, and the ranking was then analysed for distribution by the predefined factors. To test the age factor, patients were divided into younger (15 to 25 yr) and older (between 25 and 40 yr) age groups. The statistical significance of the ranked vertical, horizontal, and angular positions of impacted teeth by the investigated factors was determined using the Wilcoxon-Mann-Whitney U test., Results: The angular position of the impacted teeth was more severe in the older age group (P = 0.012) and in females (P = 0.018). The maxillary canine had more severe horizontal (P = 0.001) and angular (P = 0.003) impactions in females. Tooth agenesis was associated with less severe horizontal impaction (P = 0.041) in the mandibular second premolar. In addition, microdontia of the maxillary lateral incisor was associated with more severe horizontal impaction in general, and more severe horizontal (P = 0.024) and angular (P = 0.010) impaction of the mandibular second premolar in particular. Finally, our results showed that a retained deciduous predecessor was linked to a less severe vertical impaction of the mandibular second premolar (P = 0.030) and horizontal impaction of the maxillary second premolar (P = 0.037) but more severe angular impaction of the mandibular canine., Conclusions: This study suggests that the more delayed the treatment, being a female, the presence of maxillary lateral incisor with microdontia, and retained lower deciduous canines might be associated with more severe position of the impacted teeth. Because the severity of tooth impaction would follow different patterns when considering the investigated factors, it is mandatory to include such factors during dental diagnoses and the planning of preventive or interceptive interventions for young patients.

The purpose of this study was to evaluate the metabolism and epithelial cell proliferation of odontogenic keratocyst (OKC), dentigerous cyst (DC), and unicystic ameloblastoma (UA) by quantifying the nucleolar organizing regions (AgNORs) and Ki-67 protein immunoexpression. Forty-eight cases (16 OKC, 16 DC, and 16 UA) were evaluated retrospectively. The metabolism and epithelial cell proliferation was measured by the Ki-67 positive cell percentage index and by the mean AgNOR count in each group. The Ki-67 and AgNOR counts were significantly higher in OKC comparing to the DC and UA (p < .001). Ki-67 positive cells were observed higher in suprabasal cell layers of OKC with uniform distribution, a few of them were predominantly observed in basal cell layer in DC and UA. The AgNOR count was significantly higher in the OKC basal cell layers and observed throughout the lining epithelium of DC and UA. Ki-67 and AgNOR reinforced the aggressive character of OKC, presenting high metabolism and cellular proliferation compared to DC and UA, possibly due to its more aggressive clinical behavior and high recurrence rate. RESEARCH HIGHLIGHTS: We evidence higher metabolism and epithelial cell proliferation in OKC when compared to UA and DC, supporting its aggressive aspect and its high rate of recurrence. OKC had intense and predominant labeling of Ki-67 on the suprabasal layer unlike UA and DC., (© 2018 Wiley Periodicals, Inc.)

Introduction: In this study, we aimed to determine the effect of maxillary and mandibular posterior space discrepancies and third molar angulations on the overbite., Methods: Pretreatment lateral cephalograms of 131 subjects were analyzed. The sample included 83 open-bite and 48 deepbite subjects. A multiple regression analysis was used to evaluate the influence of maxillary and mandibular posterior space discrepancies and third molar angulations (predictor variables) on overbite. Correlations between posterior space discrepancy and third molar angulation, and correlations between predictor variables and dental angulation and height of posterior teeth and incisors were evaluated with the Pearson correlation coefficient. Subgroups with accentuated negative overbite and deepbite (27 open-bite, 37 deepbite) were compared with t tests., Results: The multiple linear regression analysis showed a positive association of the mesial angulation of the mandibular third molar with overbite. Posterior space discrepancy was negatively associated with posterior teeth mesial angulation and dentoalveolar height. However, these associations were weak, with no clinically significant implications. The deepbite subgroup showed significantly greater mesial angulation of the mandibular third molars than did the open-bite subgroup., Conclusions: There was no clinically significant effect of posterior space discrepancies and third molar angulations on overbite and dental angulation and height of posterior teeth and incisors., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective of this study was to compare the maxillary transverse dimensions between subjects with impacted maxillary canines and subjects without canine impactions, with similar vertical and sagittal features., Methods: In this retrospective study, 86 cone-beam computed tomography images of subjects with impacted maxillary canines (45 unilateral, 41 bilateral) and 67 images of subjects without dental impactions (control group) matched by similar vertical (NSAr, SArGo, ArGoMe) and sagittal (ANB, SNA, APDI) skeletal characteristics, were analyzed. The maxillary width was measured at 4 levels: first molar basal width, first molar alveolar width, first premolar basal width, and first premolar alveolar width. Group comparisons were performed with analysis of variance and post-hoc Scheffé tests. The influence of group features on the transverse dimensions was evaluated by a multiple linear regression analysis., Results: Groups with unilateral and bilateral impacted maxillary canines showed significantly smaller first molar basal widths, first molar alveolar widths, and first premolar alveolar widths compared with the control group (P = 0.030, P <0.001, and P <0.001, respectively). First premolar basal widths were not significantly different among the groups., Conclusions: Subjects with unilateral or bilateral impacted maxillary canines have smaller maxillary transverse dimensions than do subjects without impaction. Orthodontists should consider the relationship of maxillary width and canine impaction during diagnosis and treatment planning., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Aim: Aim of the study is to compare the primary and secondary healing after surgical removal of impacted mandibular third molars, in terms of swelling, severity of pain, trismus, and periodontal healing between two types of closure., Materials and Methods: A total of 60 patients, divided into two groups randomly: group A, with 30 patients in which primary closure was done; group B, with 30 patients in which secondary closure was done. A comparison between two groups was done in terms of postoperative pain, swelling, trismus at first, third, and seventh postoperative days, and periodontal healing near adjacent second molar after 6 months., Results: The swelling and pain in group A were greater than that in group B, with a statistically significant difference (p < 0.05). Mouth opening is greater in group B compared to group A. There is no significant difference in periodontal healing in between two groups after 6 months. Complication like alveolar osteitis was noted in 1 patient (3.3%) in group B., Conclusion: We conclude that secondary closure was better than primary closure in terms of postoperative pain, swelling, and trismus. Irrespective of any closure technique, there is no difference in terms of periodontal healing.

Background: The aetiology of the canine displacement still remains controversial. Some authors implicated a deficiency in maxillary width as a local mechanical cause for impacted canines. The aim of the study was to examine whether there is a relationship between impacted maxillary canines, early diagnosed by using panoramic radiographs, and the morphology of the maxilla on 3D model casts., Methods: The displaced maxillary canines (DMC) group consisted of 24 patients (mean age, 9.1 ± 1.1 years), while the control group consisted of 25 subjects (mean age, 8.7 ± 0.9 years). Seven measurements were calculated on the digital casts of each subject: intermolar width (IMW), arch length (AL), depth of the palatal vault (PVD), available arch space (AAS), the sum of the anterior segments (SAS), the right/affected (R-Af) and left/unaffected (L-Un) available spaces., Results: Both IMW and AL in the DMC group were significantly decreased relative to the control group (P < 0.01), indicating that patients with displaced canines presented a shorter and narrower palate than subjects without eruption problems. Moreover, the values of the SAS and AAS were significantly decreased (P < 0.01) in the DMC group relative to the controls., Conclusions: The shape of the maxillary arch was narrower and shorter in the displaced maxillary canines group compared with the control group.

Objective: To investigate the characteristics of the dental phenotype in patients with cleidocranial dysplasia (CCD) using longitudinal data., Materials and Methods: Twelve unrelated Korean CCD patients were observed using a longitudinal series of radiographs and clinical photographs. Statistical analysis was performed on the dental phenotypic data., Results: Although dysplasia of the clavicles, open fontanelle, and wormian bone were observed in all 12 patients, delayed fusion of the mandibular symphysis was found in four patients. One patient did not have a supernumerary tooth (ST). However, 62 STs were found in 11 patients (mean, 5.6 per patient; range of ST emergence, 5 years 6 months-14 years 8 months; developing position, occlusal to the permanent incisors, canines, and premolars and distal and apical to the permanent molars). The mandibular premolar region was the most frequent area of ST development (50.0%, P < .001). All 12 patients showed impacted permanent teeth (IPT), including one patient without ST (mean, 17.8 per patient). Impaction occurred most frequently in the mandibular premolar region and least frequently in the maxillary molar region (93.8% vs 39.6%, P < .01). The ratio of spontaneous eruption of IPT after removal of retained deciduous teeth and/or ST was highest for the maxillary and mandibular incisors (all 54.6%) and lowest for the mandibular canines and premolars (26.7% and 28.9%, respectively); however, the difference was not significant., Conclusions: The emergence time and development position of ST and the root development of IPT should be considered to determine the timing for the removal of ST and forced eruption of IPT.

This study examined the prevalence, characteristic features, and complications associated with the occurrence of unerupted permanent incisors among children and adolescents attending a university dental teaching hospital. A retrospective review was performed of the clinical records of children and adolescents who attended the Prince Philip Dental Hospital, Hong Kong between 2005 and 2014. All patients who had at least one unerupted permanent incisor tooth were included. A total of 266 subjects with 320 unerupted permanent incisors were identified. The prevalence of unerupted permanent incisors among children and adolescents was 2.0%. Permanent maxillary central incisors (70.6%) were the most commonly affected teeth. The most common cause for unerupted incisors were dilacerations (n = 83, 36.7%) for maxillary central incisors; developmental dental anomalies (n = 22; 30.6%) together with unfavorable root development (n = 22; 30.6%) for maxillary laterals incisors; and abnormal tooth/tissue ratio (n = 11, 50.0%) for mandibular incisors. A majority of unerupted incisors presented with complications the most common being ectopic/displacement/rotation of the unerupted incisors (46.6%), loss of space (36.9%) and midline shift (27.5%). In conclusion, the causes were distinct for different manifestations of unerupted permanent incisors. As the majority of unerupted incisors presented with complications, a systematic and organized method of history taking as well as clinical and radiographic examinations is mandatory in the diagnosis of unerupted permanent incisors., Competing Interests: The authors have declared that no competing interests exist.

Introduction: The severity of a palatally impacted canine (PIC) is gauged radiographically on 2-dimensional and 3-dimensional positional components: eg, angulation and height. We hypothesized that the position of a PIC relative to its virtual alignment in the arch is a better indication of impaction severity and treatment requirements. The aims of this research were to evaluate variations in PIC location on 3-dimensional images and to determine positional components associated with impaction severity., Methods: Linear and angular measurements of 38 PICs from 28 cone-beam computed tomography scans were made on the panoramic, coronal, sagittal, and axial sections. Measurements included angulation of the PIC to the virtually aligned canine, midline, and palatal plane; and distances between cusp tip and apex to various reference planes-eg, occlusal and midpalatal. Statistical assessments comprised t tests for group comparisons based on PIC and virtually aligned canine severity (cutoff at 30°) and Pearson product moment correlations for associations among variables., Results: Angulations of the PIC to the virtually aligned canine were 32.5° ± 15.5° (range, 9°-59°) and 19.6° ± 6.9° and 45.37° ± 9.6°, respectively, in the less severe and more severe groups (P <0.001). Group differences were significant (0.023 

Objectives: To evaluate prevalence, distribution, and sexual dimorphism of dental anomalies (DA) among different skeletal malocclusions (SM) and growth patterns (GP) under the hypothesis that specific clinical patterns exist and may indicate common etiological roots., Materials and Methods: A total of 1047 orthodontic records of patients older than 8 years were evaluated. The SN-GoGn angle was used to classify GP (hypodivergent, normal, and hyperdivergent), and the ANB angle was used to verify SM (Angle Classes I, II, and III). These assessments were done from lateral cephalometric radiographs. DA were diagnosed using panoramic radiographs by one calibrated investigator. Odds ratios, chi-square, and Student's t-tests were used., Results: Of the subjects, 56.7% were female, with mean age of 16.41 (±10.61) years. The prevalence of DA was 15.7%. Impaction and tooth agenesis were the most prevalent DA, with relative frequencies of 14.4% and 9.7%, respectively. DA were most prevalent in Class III SM (80.8%) and in hypodivergent GP (82.5%), although this was not statistically significant. Tooth agenesis ( P < .01) and microdontia ( P = .025) were significantly more common among hypodivergent GP and Class III SM, respectively., Conclusions: The results of this study support the idea that DA are preferentially associated with certain patterns of malocclusion.

Objective: Introduction: The most pronounced thinning of the enamel is in the intercuspal fissures of the third molars, which are characterized by a wide variety of shapes and sizes up to the abnormal disruption of their development and teething, which often causes all kinds of clinical complications. The aim: The purpose of the paper was to obtain the data on the structural state of the third molars and identify their most damaged areas in the latent form of dental caries., Patients and Methods: Materials and Methods: 10 lower third molars with an intact crown without clear external signs of tooth decay have been examined. The teeth were embedded into epoxy resin, using the "Himkontakt-Epoxy" glue. Upon the completion of full polymerization, the resulting epoxy blocks were cut by the separation disk. Afterwards, the cross-cut ends with the naked tooth tissues were grinded and polished to obtain even unscratched slice, which was subsequently etched in Trilon-B (disodium salt EDTA) with the follow up staining in 1% borax methylene blue solution. Epoxy tooth slices were studied with the light optics in the reflected light using the MBS-9 binocular loupe, equipped with a digital camera adapter., Results: Results: The process of tooth decay is of endogenous origin. The specimen of the third lower molar shows all pathomorphological signs of the latent carious lesions. Impacted lower third molar with deep carious was detected. It is obvious that, being in the subcortical zone of the alveolar ridge of the lower jaw, this abnormally developed tooth could not be exposed to any external effects., Conclusion: Conclusions: The microscopic study of the tooth, found in the ovarian dermoid cysts, showed that it was affected by caries that completely excludes the exogenous factors in its origination. We hypothesize that the mechanism of tooth decay directly involves the immune responses, antigens of which are (in certain circumstances) proteins of the dentin and enamel. This is the rationale for introduction into the current nosology the term "carious disease" instead of "dental caries".

Objective: Fluoride excess of 0.05-0.07mgF/kgbw/day in water or food additives like salt is the principal cause of endemic dental fluorosis. How fluoride causes these defects is not clear yet. Recent studies in rodents suggest that development of enamel fluorosis is associated with insufficient neutralization of protons released during the formation of hypermineralized lines., Design: Here we examined whether hypermineralization could also be assessed by MicroCT in developing molar enamel of humans exposed to fluoride., Result: Micro-CT analysis of hypomineralized enamel from human fluorotic molars graded by the Thylstrup-Fejerskov (TF) Index as III-IV showed weak hypermineralized lines and hypermineralized patches not seen in TF-I/II grade enamel. The mesio-distal sides of these molar teeth were significantly smaller (∼18%, p=0.02) than in TF-I/II teeth., Conclusion: The patterns of changes observed in human fluorotic teeth were similar to those in fluorotic rodent incisors. The data are consistent with the hypothesis that also in developing human teeth fluoride-stimulated local acidification of enamel could be a mechanism for developing fluorotic enamel., (Copyright © 2017. Published by Elsevier Ltd.)

Introduction: The aim of this study was to analyze the development and stability of roots and alveolar bone in orthodontically treated labial inversely impacted maxillary central incisors in a long-term follow-up by cone-beam computed tomography. Comparisons were made between the labial inversely impacted maxillary central incisors after treatment and normally erupted mature contralateral incisors., Methods: The sample consisted of 12 participants, with a mean age of 7.80 ± 0.91 years. Cone-beam computed tomography scanning data at the completion of treatment and the long-term follow-up were available for each participant.The mean length of follow-up was 24.57 ± 4.33 months. Root length, crown height, root canal width, labial/lingual alveolar bone vertical loss, and bone thickness of the impacted and contralateral incisors were measured with the SimPlant Pro program (version 13.0; Materialise Dental, Leuven, Belgium)., Results: In the follow-up, the root lengths of both the labial inversely impacted dilacerated maxillary central incisors (10.99 ± 1.96 mm) and the contralateral mature maxillary central incisors (11.65 ± 1.37 mm) were significantly longer than at posttreatment (8.37 ± 1.74 mm and 9.81 ± 1.65 mm, respectively). The root canal widths of the impacted and contralateral incisors were significantly narrower during the follow-up. The size of the angle between the long axis of the crown and apical third of the root decreased significantly. The lingual alveolar bone loss of the impacted incisors was greater than that of the contralateral incisors. The labial bone thickness at the apex of the impacted incisors increased significantly during the follow-up period., Conclusions: The treated labial inversely impacted maxillary central incisors had continuous and similar growth as did the mature contralateral incisors in the follow-up period. The roots had an increase in length and a change in direction of the apex, with a relatively stable condition of the surrounding alveolar bone. Neither the labial inversely impacted maxillary central incisors nor the contralateral incisors had further alveolar bone loss., (Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: Cephalometric and arch measurements might predict the occurrence of a palatally-displaced impacted maxillary canine (PDC). Despite their clinical importance, studies in this regard are limited and controversial., Methods: In this case-control study, 35 PDC patients and 77 controls aged over 13 years were examined. Eleven cephalometric measurements: N-S, ANS-PNS, ANS-N, S-N-ANS, facial angle (FH/NPog), SNA, SNB, Y-axis (SN/SGn), gonial angle, Go-Gn/SN, and Jarabak Index were performed. The maxillary and mandibular intermolar and interpremolar widths were measured. Patients' sagittal skeletal relationships and centric occlusions (molar) were measured by radiographic and cast examinations. The differences between the two groups in terms of the above-mentioned cephalometric and anatomic variables were assessed using Chi 2 and Mann-Whitney U-tests (α=0.05)., Results: Chi 2 showed a significant negative association between dentoalveolar class I (molar) and PDC occurrence (P=0.018), but not between PDC and skeletal sagittal relationships. Facial angle (FH/NPog) and Y-axis (SN/SGn) were more obtuse in patients with PDC (P<0.05). No arch dimensions differed between the two groups., Conclusions: PDC tends to accompany molar class II/III but is not associated with upper or lower jaw widths or lengths. Vertical dimensions might be smaller in PDC patients. Some variables were inconclusive and need future assessments., (Copyright © 2016 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: The purpose of this study was to determine the arch form of the root apices of normally erupting teeth and then determine the differences in the location of the apex of impacted canines relative to normally erupting canines. In addition, we sought to determine whether the labiopalatal position of the impacted canines influences the position of the apices., Methods: The study included 21 patients with unerupted canines that subsequently had a normal eruption, 21 patients with palatally impacted canines, 27 patients with labially impacted canines, and 17 patients with midalveolus impacted canines. Images were obtained using cone beam computed tomography, and the x, y, and z coordinates of the root apices were determined using Ondemand3D software (Cybermed Co., Seoul, Korea). Two-dimensional coordinates were converted from acquired 3-dimensional coordinates via projection on a palatal plane, and the Procrustes method was used to process the converted 2-dimensional coordinates and to draw the arch forms of the root apices. Finally, we measured the extent of root apex deviation from the arch forms of the root apices., Results: Normally erupting canines showed that even though calcifications may be immature, their positions were aligned with a normal arch form. The root apices of the impacted canines were an average of 6.572 mm away from the root apices' arch form, whereas those of the contralateral nonimpacted canines were an average distance of 2.221 mm away, a statistically significant difference. The palatally impacted canines' root apices distribution tended toward the first premolar root apices., Conclusions: Incompletely calcified, unerupted teeth with a subsequent normal eruption showed a normal arch form of the root apices. The root apices of impacted canines were farther from the arch forms than were the nonimpacted canines. Also, the root apices of impacted canines in the palatal area showed distributions different from those of the other impacted canine groups., (Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)