Comparison of the mandibular retromolar space in adults with different sagittal skeletal types and eruption patterns of the mandibular third-molar: a cone-beam computed tomography study.

BACKGROUND: The mandibular retromolar space (RMS) has not been extensively studied in relation to various sagittal skeletal classes and patterns of third-molar eruption. The objective of this study was to test the null hypothesis that there is no difference in the mandibular RMS among normodivergent subjects with different skeletal classes and patterns of mandibular third-molar eruption, using cone-beam computed tomography (CBCT). METHOD: A total of 105 normodivergent patients (20-40 years) were included in this study. Participants were categorized into Class I, II and III groups based on ANB and further impacted and erupted groups based on the eruption patterns of the mandibular third molars. Measurements of the mandibular RMS were taken at four planes parallel to the occlusal plane, along the cusp line. Comparative analyses were conducted among the three sagittal groups and between the impacted and erupted groups. RESULTS: The Class II group exhibited a statistically smaller RMS (P < 0.05). RMS was found to be larger in third-molar erupted group (P < 0.05). The rates of root contact and third-molar impaction was significantly higher in Class II group. (P < 0.05) CONCLUSIONS: The null hypothesis was rejected. Patients with Skeletal Class II tend to have a smaller mandibular RMS and a higher prevalence of root contact and third-molar impaction. The presence of impacted mandibular third molars was correlated with a shorter RMS. TRIAL REGISTRATION: Retrospectively registered.

Clinical and radiographic assessment of gummy smile patients with altered passive eruption: a cross-sectional study in a Thai population.

OBJECTIVES: The study aimed to evaluate the clinical crown length (CCL) among patients diagnosed with altered passive eruption (APE), the causes of a gummy smile, the prevalence of APE, and the correlation between parameters. MATERIALS AND METHODS: A total of 86 gummy smile patients (516 teeth) underwent clinical examination and assessment using cone-beam computed tomography (CBCT), photography, and intraoral scanning. RESULTS: Significantly shorter CCL and distance between the cementoenamel junction and bone crest (CEJ-BC) were observed among APE-affected teeth (p < 0.05). Among the patients, 56.1% of patients were diagnosed with APE, and most of them were affected by a combination of APE and hypermobile upper lip (HUL). Based on 183 APE-affected teeth, the prevalence of APE types and subtypes was as follows: APE1A (96; 19.3%), APE1B (78; 15.9%), APE2A (8; 1.6%), and APE2B (1; 0.2%). Positive correlations were found between keratinized gingival width (KGW) and bone thickness (BT), while negative correlations were observed between gingival thickness (GT) and BT. CONCLUSION: Shorter CCL and CEJ-BC were the highlighted features of APE. APE affected approximately half of the gummy smile patients, with most of them presenting with a combination of HUL. Almost teeth affected by APE were classified as Type I, with a nearly equal distribution between subtypes A and B. CLINICAL RELEVANCE: The clinical and radiographic features of APE contribute to a better understanding of this condition and facilitate the management of patients affected by APE. Approximately half of gummy smile patients will require multidisciplinary treatment.

Do erupting maxillary canines resorb adjacent teeth? A study focusing both on the ipsilateral and contralateral sides among individuals with unilaterally impacted canines.

OBJECTIVES: To determine the prevalence of root resorption of teeth adjacent to permanent maxillary canines on both sides, by cone-beam computed tomography (CBCT), in pretreatment adolescent subjects with unilaterally impacted maxillary canines, and to define predictive factors for the root resorption. MATERIALS AND METHODS: This retrospective sample included 76 adolescents (38 boys, 38 girls, mean age 12.3 ± 2.1 years; range 8-17 years) who had CBCT after detection of a unilateral impacted maxillary canine before any active orthodontic treatment. Both ipsilateral and contralateral sides were examined, and 14 qualitative and quantitative variables were collected. Descriptive statistics were calculated, and multiple logistic regression was used to predict root resorption. RESULTS: On the impaction side, 57.9% of canines resorbed at least one adjacent tooth compared with 13.2% on the contralateral side (P < .001). On the impaction side, resorption was slight in 59.6%, moderate in 5.8%, and severe in 34.6% of the cases. On the contralateral side, resorption was slight in 91.7%, moderate in 0%, and severe in 8.3% of the cases. On both sides, upper lateral incisors were the teeth most frequently resorbed, followed by the upper first premolars and upper central incisors. The presence of contact between the canine and the adjacent roots was the only statistically significant risk factor for resorption for both ipsilateral and contralateral sides. CONCLUSIONS: Orthodontists should look for root resorption on both sides in cases of unilaterally impacted maxillary canines.

Percepção dos pais sobre os sinais e sintomas decorrentes da erupção dentária em bebês / Parents' perception about tooth eruption signs and symptoms in babies

A erupção dentária é definida como a movimentação dos dentes em desenvolvimento para emergir através dos tecidos moles da maxila e da mandíbula. O primeiro dente decíduo geralmente irrompe na cavidade bucal em um intervalo entre quatro e dez meses de idade e manifestações locais e sistêmicas associadas à erupção são observadas e relatadas por pais de bebês que passam pelo processo. Deste modo, este trabalho busca revisar e analisar a literatura em relação à percepção dos pais sobre os sinais e sintomas observados durante o processo de erupção dentária em bebês. Foi realizada uma revisão integrativa da literatura, buscando por artigos indexados nas bases eletrônicas de dados PubMed e Portal BVS. Ao final, foram selecionados 16 artigos científicos, sendo em sua maioria estudos com delineamento transversal (n: 11). Apenas dois estudos foram realizados no Brasil, sendo a Índia (n: 4) o país com maior número de artigos incluídos. Os sinais e sintomas mais relatados pelos pais foram febre (n: 16), perda de apetite (n: 13) e aumento da salivação (n: 12). Os estudos analisados apresentaram limitações, como a falta de padronização dos questionários direcionados aos pais. Compreende-se, desta forma, que mais estudos com populações variadas, amostras maiores e questionários padronizados são necessários.

Dental eruption is defined as the movement of developing teeth to emerge through the soft tissues of the maxilla and mandible. The first deciduous tooth usually erupts into the oral cavity between the fourth and tenth month of age. During this time, local and systemic manifestations are observed and reported by parents of babies who undergo the process. Thus, this stud seeks to review and analyze the literature regarding the perception of parents about the signs and symptoms observed during the process of tooth eruption in babies. An integrative literature review was performed, searching for articles indexed in PubMed and Portal BVS electronic databases. Sixteen papers were selected, mostly of which were cross-sectional studies (n: 11). Only two studies were carried out in Brazil, with India (n: 4) being the country with the highest number of articles included. The most reported signs and symptoms were fever (n: 16), loss of appetite (n: 13) and increased salivation (n: 12). The analyzed studies had limitations, such as the lack of standardization of the questionnaires addressed to parents. We conclude more studies with varied populations, larger samples and standardized questionnaires are needed.

Exploring the factors driving higher interactions in false amber necklace posts on Facebook.

The consumption and sharing of information on social media contribute to the circulation of false health content. In this sense, popular belief-driven posts recommending the use of amber necklaces to prevent symptoms of teething can be easily found on social media, even when they offer health risks for children. Accordingly, this study aimed to characterize posts in Portuguese by identifying message-based factors associated with higher user interactions of Facebook. A total of 500 Facebook posts published in Portuguese between August 2016 and August 2021 were retrieved by CrowdTangle, and analyzed quantitatively according to time of publication, total user interaction, and post overperforming score, and then qualitatively by two independent investigators, according to motivation, authors' profiles, and sentiment. The data were evaluated by descriptive analysis, Mann-Whitney U test, chi-square test, and multiple logistic regression models regarding interaction metrics. The posts were published predominantly by commercial profiles, with social, psychological, and financial motivations, and expressed positive sentiment. Furthermore, time of publication (OR=2.65), regular user profiles (OR=3.30), and neutral/negative sentiment (OR=2.76) were associated positively with total interactions, whereas only time of publication was associated with post overperforming scores (OR=1.65). In conclusion, Facebook posts promoting efficacy of amber necklaces in managing teething symptoms are primarily created by commercial profiles with vested interests in marketing the product. The key factors that contribute to the success of posts containing false information about amber necklaces on Facebook can be identified by considering the author's profile, sentiment, and time of publication.

Evolution of tooth morphological complexity and its association with the position of tooth eruption in the jaw in non-mammalian synapsids.

Heterodonty and complex molar morphology are important characteristics of mammals acquired during the evolution of early mammals from non-mammalian synapsids. Some non-mammalian synapsids had only simple, unicuspid teeth, whereas others had complex, multicuspid teeth. In this study, we reconstructed the ancestral states of tooth morphological complexity across non-mammalian synapsids to show that morphologically complex teeth evolved independently multiple times within Therapsida and that secondary simplification of tooth morphology occurred in some non-mammalian Cynodontia. In some mammals, secondary evolution of simpler teeth from complex molars has been previously reported to correlate with an anterior shift of tooth eruption position in the jaw, as evaluated by the dentition position relative to the ends of component bones used as reference points in the upper jaw. Our phylogenetic comparative analyses showed a significant correlation between an increase in tooth complexity and a posterior shift in the dentition position relative to only one of the three specific ends of component bones that we used as reference points in the upper jaw of non-mammalian synapsids. The ends of component bones depend on the shape and relative area of each bone, which appear to vary considerably among the synapsid taxa. Quantification of the dentition position along the anteroposterior axis in the overall cranium showed suggestive evidence of a correlation between an increase in tooth complexity and a posterior shift in the dentition position among non-mammalian synapsids. This correlation supports the hypothesis that a posterior shift of tooth eruption position relative to the morphogenetic fields that determine tooth form have contributed to the evolution of morphologically complex teeth in non-mammalian synapsids, if the position in the cranium represents a certain point in the morphogenetic fields.

Teething - filling in the gaps .

Dentists and dental care professionals may be faced with concerns from parents and carers regarding teething in infants and young children. Teething is a normal physiological and self-limiting process; however, the diverse signs and symptoms that have, over time, been attributed to teething, can make diagnosis challenging. Appropriate diagnosis is crucial in preventing the potentially life-threatening sequalae of dismissing symptoms as teething and delaying appropriate treatment of a systemically unwell child. Management of teething can be approached in a five-step process based on the National Institute for Health and Care Excellence clinical knowledge summary on teething. These include: 1) history-taking, clinical examination, diagnosis and referral of systemically unwell or severely distressed children for urgent medical review; 2) providing parental/carer reassurance, information and preventative advice; 3) simple, non-pharmacological management strategies; 4) pharmacological intervention; 5) safety-netting advice in case the child becomes systemically unwell, has prolonged symptoms, or is in severe distress. The purpose of this article is to bridge knowledge gaps regarding teething to enable appropriate diagnosis and encourage dissemination of preliminary information and ensure appropriate referral by frontline dental professionals.

How do teeth erupt?

The development of normal occlusion requires eruptive migration of teeth from their developmental position in the jaw into a functional position within the oral cavity. This process involves significant and coordinated movement in an axial direction and appropriate eruption through the gingival tissues. The mechanisms regulating these developmental events are poorly understood, and teeth retain eruptive potential throughout their lifespan. In recent years, the use of mouse models has helped to elucidate some of the underlying molecular and biological mechanisms of mammalian tooth eruption. Here, we outline our current understanding of tooth eruption mechanisms and discuss their relevance in terms of known human disorders of tooth eruption.

The effect of occlusal loading on secondary tooth eruption: An experimental study using a rat model.

This study aimed to assess the impact of occlusal loading on secondary tooth eruption and to determine the extent to which altering the occlusal loading influences the magnitude of secondary eruption through an experimental rat model. The present sample consisted of 48 male Wistar rats. At the onset of the experiment, 24 rats were 4 weeks old (young rats) and 24 rats were 26 weeks old (adult). Within each age group, the rats were further divided into two equal subgroups (12 rats each), receiving either a soft- or hard-food diet for the 3-month duration of the experiment. The primary outcome was the tooth position changes relative to stable references in the coronal plane by evaluating the distance between the mandibular first molars and the inferior alveolar canal. Microcomputed tomography scans were taken from all rats at three standardized intervals over the 3-month study period. Descriptive statistics were calculated by age and diet over time, and the evolution of the outcomes were plotted by age and diet over time. Longitudinal data analysis via generalized estimating equations was performed to examine the effect of age, diet and time on the primary outcomes. Secondary tooth eruption was observed in all age groups (young and adult) regardless of diet consistency (soft or hard food). In young rats, the secondary eruption was greater in the animals fed a soft diet than those fed a hard diet. In adult rats, minimal difference in secondary tooth eruption were found between different diet consistencies. Occlusal loading influences secondary tooth eruption in teeth with an established occlusal contact. The quantity of eruption in growing rats is higher when occlusal loading is less, providing a certain amount of secondary tooth eruption occurs. This difference, however, is not evident in adult rats, at least during the given 3-month time frame.

Tooth eruption disorder: 2 cases. / Doorbraakstoornis van een gebitselement: 2 casussen.

Tooth eruption disorders can have several different causes and treatment options. An 8-year-old boy's tooth 12 erupted in the position of tooth 11, and an 11-year-old girl's tooth 21 did not erupt. In both cases, an attempt was made to regulate the relevant tooth orthodontically, but ultimately it was found necessary to extract the tooth. Tooth replacement is possible with autotransplantation or prostheses. Implantology rarely is the first choice for young patients.

Epigenetic markers of tooth eruption - DNA methylation and histone acetylation.

The present study aimed to evaluate whether epigenetic markers are expressed in the dental follicles surrounding ectopically erupting teeth. Twenty-one dental follicles were collected in 20 adolescent children through surgical exposure of ectopic teeth. The epigenetic modifications of DNA methylation and histone acetylation were evaluated by immunohistochemistry. The results showed cells positive for DNA-methyltransferase 1 (DNMT1), DNA methyltransferase 3 beta (DNMT3B), ten-eleven translocation-2 (TET2), acetyl-histone H3 (AcH3), acetyl-histone H4 (AcH4), 5-methylcytosine (5mC), and 5-hydroxymethylcytosine (5hmC) were present in all the samples. The levels of epigenetic markers representing active chromatin (5hmC, AcH3, AcH4, and TET2) were statistically significantly higher than those of markers representing inactive chromatin (5mC, DNMT3B, DNMT1). In conclusion, follicles in ectopic teeth display major epigenetic modifications. In the follicles, epigenetic markers associated with the activation of bone-related genes are more abundant than markers associated with the inactivation of bone-related genes.

Abnormal dental follicle cells: A crucial determinant in tooth eruption disorders (Review).

The dental follicle (DF) plays an indispensable role in tooth eruption by regulating bone remodeling through their influence on osteoblast and osteoclast activity. The process of tooth eruption involves a series of intricate regulatory mechanisms and signaling pathways. Disruption of the parathyroid hormone­related protein (PTHrP) in the PTHrP­PTHrP receptor signaling pathway inhibits osteoclast differentiation by DF cells (DFCs), thus resulting in obstructed tooth eruption. Furthermore, parathyroid hormone receptor­1 mutations are linked to primary tooth eruption failure. Additionally, the Wnt/ß­catenin, TGF­ß, bone morphogenetic protein and Hedgehog signaling pathways have crucial roles in DFC involvement in tooth eruption. DFC signal loss or alteration inhibits osteoclast differentiation, affects osteoblast and cementoblast differentiation, and suppresses DFC proliferation, thus resulting in failed tooth eruptions. Abnormal tooth eruption is also associated with a range of systemic syndromes and genetic diseases, predominantly resulting from pathogenic gene mutations. Among these conditions, the following disorders arise due to genetic mutations that disrupt DFCs and impede proper tooth eruption: Cleidocranial dysplasia associated with Runt­related gene 2 gene mutations; osteosclerosis caused by CLCN7 gene mutations; mucopolysaccharidosis type VI resulting from arylsulfatase B gene mutations; enamel renal syndrome due to FAM20A gene mutations; and dentin dysplasia caused by mutations in the VPS4B gene. In addition, regional odontodysplasia and multiple calcific hyperplastic DFs are involved in tooth eruption failure; however, they are not related to gene mutations. The specific mechanism for this effect requires further investigation. To the best of our knowledge, previous reviews have not comprehensively summarized the syndromes associated with DF abnormalities manifesting as abnormal tooth eruption. Therefore, the present review aims to consolidate the current knowledge on DFC signaling pathways implicated in abnormal tooth eruption, and their association with disorders of tooth eruption in genetic diseases and syndromes, thereby providing a valuable reference for future related research.

Jurassic fossil juvenile reveals prolonged life history in early mammals.

Living mammal groups exhibit rapid juvenile growth with a cessation of growth in adulthood1. Understanding the emergence of this pattern in the earliest mammaliaforms (mammals and their closest extinct relatives) is hindered by a paucity of fossils representing juvenile individuals. We report exceptionally complete juvenile and adult specimens of the Middle Jurassic docodontan Krusatodon, providing anatomical data and insights into the life history of early diverging mammaliaforms. We used synchrotron X-ray micro-computed tomography imaging of cementum growth increments in the teeth2-4 to provide evidence of pace of life in a Mesozoic mammaliaform. The adult was about 7 years and the juvenile 7 to 24 months of age at death and in the process of replacing its deciduous dentition with its final, adult generation. When analysed against a dataset of life history parameters for extant mammals5, the relative sequence of adult tooth eruption was already established in Krusatodon and in the range observed in extant mammals but this development was prolonged, taking place during a longer period as part of a significantly longer maximum lifespan than extant mammals of comparable adult body mass (156 g or less). Our findings suggest that early diverging mammaliaforms did not experience the same life histories as extant small-bodied mammals and the fundamental shift to faster growth over a shorter lifespan may not have taken place in mammaliaforms until during or after the Middle Jurassic.

Etiological Mechanisms and Genetic/Biological Modulation Related to PTH1R in Primary Failure of Tooth Eruption.

Primary failure of eruption (PFE) is a rare disorder that is characterized by the inability of a molar tooth/teeth to erupt to the occlusal plane or to normally react to orthodontic force. This condition is related to hereditary factors and has been extensively researched over many years. However, the etiological mechanisms of pathogenesis are still not fully understood. Evidence from studies on PFE cases has shown that PFE patients may carry parathyroid hormone 1 receptor (PTH1R) gene mutations, and genetic detection can be used to diagnose PFE at an early stage. PTH1R variants can lead to altered protein structure, impaired protein function, and abnormal biological activities of the cells, which may ultimately impact the behavior of teeth, as observed in PFE. Dental follicle cells play a critical role in tooth eruption and root development and are regulated by parathyroid hormone-related peptide (PTHrP)-PTH1R signaling in their differentiation and other activities. PTHrP-PTH1R signaling also regulates the activity of osteoblasts, osteoclasts and odontoclasts during tooth development and eruption. When interference occurs in the PTHrP-PTH1R signaling pathway, the normal function of dental follicles and bone remodeling are impaired. This review provides an overview of PTH1R variants and their correlation with PFE, and highlights that a disruption of PTHrP-PTH1R signaling impairs the normal process of tooth development and eruption, thus providing insight into the underlying mechanisms related to PTH1R and its role in driving PFE.

Association of parent-reported timing of first tooth emergence and ECC: a secondary analysis of a case-control study.

PURPOSE: Tooth eruption is a dynamic process. Appearance of any part of the cusp through gingiva may be a clinical marker of eruption. Early childhood caries (ECC) is a public health problem globally. This study aimed to assess the relationship between parent-reported timing of first tooth emergence and ECC in toddlers. METHODS: This study is a secondary data analysis of 627 toddlers involved in a case-control study on sleep-time feeding practises in children. The children were categorised into four groups based on the parent-reported timing of first primary tooth emergence (G1-when the first primary tooth emerged before 6 months of age, G2-between 7 and 9 months; G3-10 to 12 months and G4-when the first primary tooth emerged after 12 months of age). Univariate binary logistic regression analysis was performed to evaluate the association between timing of first tooth emergence and ECC. RESULTS: The mean age of the children was 24.4 ± 7.3 months (cases, that is children with ECC-25.4 ± 6.9 months, controls, that is children without ECC-23.6 ± 7.5 months). Of 60 children, whose first tooth erupted before 6 months of age, 35 (12%) were cases compared to 25(8%) controls. Amongst the cases, boys had more caries than girls (p < 0.05). Of the anterior teeth, 22% of the emerged teeth were decayed in the first group, followed by 19%, 16% and 10% in the second, third and fourth groups, respectively (p < 0.05). Analysis of the posterior teeth showed a lower percentage of decayed teeth with delayed emergence of the first primary tooth (p < 0.05). Children whose teeth emerged before 6 months of age had an odds ratio of 3.5 (95% CI 1.49, 8.42) (p = 0.004). CONCLUSION: This study concluded that the early emergence of the first primary tooth, as reported by the parent, was associated with an increased risk of developing ECC.

Early onset of enamel formation in Baka pygmy's deciduous canines.

OBJECTIVE: Our aim was to evaluate by enamel microstructure analysis two hypotheses that would explain the early dental eruption in the Bakaparticularity, a shorter crown formation time and/or earlier onset of crown formation. DESIGN: Deciduous canines corresponds to the best teeth to perform the analysis of enamel microstructure. Longitudinal ground sections of 21 deciduous canines from 12 individuals were studied with transmitted light microscopy. Cross-striations, striaes of Retzius (SR) and the neonatal line (NNL) enable to establish the prenatal crown formation time (preCFT), the postnatal crown formation time (postCFT), the crown formation time (CFT) as well as the daily secretion rate (DSR) and the enamel extension rate (EER) and their variation along crown formation. RESULTS: The DSR and the EER in the Baka are similar than in other populations with an average DSR of 3.26 µm and EER of 18.18 µm. The preCFT was 154 days, the postCFT 265 days and CFT 419 days. Comparison with other population does not show difference in CFT. However, the preCFT and the postCFT differ, the first is higher and the second lower in the Baka than in other populations. Furthermore, the number of prenatal areas of enamel was greater in the Baka. CONCLUSION: Our analysis suggests that the Baka does not distinguish by a different CFT but the onset of crown formation is earlier than in other groups. Therefore, the early dental eruption in the Baka results from an earlier onset of crown formation.

Third molar eruption in dental panoramic radiographs as a feature for forensic age assessment - new reference data from a German population.

Forensic age assessment in the living can provide legal certainty when an individual's chronological age is unknown or when age-related information is questionable. An established method involves assessing the eruption of mandibular third molars through dental panoramic radiographs (PAN). In age assessment procedures, the respective findings are compared to reference data. The objective of this study was to generate new reference data in line with the required standards for mandibular third molar eruption within a German population. For this purpose, 605 PANs from 302 females and 303 males aged 15.04 to 25.99 years were examined. The PANs were acquired between 2013 and 2020, and the development of the mandibular third molars was rated independently by two experienced examiners using the Olze et al. staging scale from 2012. In case of disagreement in the assigned ratings, a consensus was reached through arbitration. While the mean, median and minimum ages were observed to increase with each stage of mandibular third molar eruption according to the Olze method, there was considerable overlap in the distribution of age between the stages. The minimum age for stage D, which corresponds to complete tooth eruption, was 16.1 years for females and 17.1 years for males. Thus, the completion of mandibular third molar eruption was found in both sexes before reaching the age of 18. In all individuals who had at least one tooth with completed eruption and who were younger than 17.4 years of age (n = 10), mineralization of the teeth in question was not complete. Based on our findings, the feature of assessing mandibular third molar eruption in PAN cannot be relied upon for determining age of majority.

Studying eruption patterns of mandibular third molars for forensic age assessment: Introducing current reference data from a population of black South Africans.

INTRODUCTION: Evaluation of the eruption of mandibular third molars in orthopantomograms (OPGs) is a method of forensic age assessment. The objective of our study was to provide valid reference data for this trait within a population of black South Africans. The study was guided by the criteria for reference studies in age assessment. MATERIALS AND METHODS: A study population from Pretoria, South Africa comprising 670 OPGs obtained from 338 black females and 332 black males aged between 15.00 and 25.97 years was analysed. All OPGs were performed for medical indication during the period from 2011 to 2022 and were retrospectively evaluated. From the 670 OPGs, a total of 1021 mandibular third molars were evaluated. The assessment of mandibular third molars was conducted using the staging scale presented by Olze et al. in 2012. Two experienced dentists evaluated the OPGs independently of each other. If the two examiners diverged in their assessments, a consensus stage was assigned. RESULTS: As expected, the mean, median and minimal age increased with higher stages for both teeth and both sexes. The minimum age recorded for stage D, indicating complete tooth eruption, was 15.79 years in females and 16.62 years in males. CONCLUSION: As it is the case for previous reference studies in other countries, placing exclusive reliance on the evaluation of mandibular third molar eruption is inadequate for ascertaining the age of majority among Black South Africans. Future studies need to examine if our results are transferable to other countries in Sub-Saharan Africa.

Periodontal outcomes of surgically exposed and orthodontically aligned buccally impacted maxillary canines: A systematic review and meta-analysis.

OBJECTIVE: To compare the periodontal outcomes of surgically exposed and orthodontically aligned buccally impacted maxillary canines to spontaneously erupted maxillary canines. DATA SOURCES: An unrestricted search was carried out of indexed databases (Medline, EMBASE, Web of Science and Scopus), reference lists of included studies, and grey literature published until December 2023. DATA SELECTION: Observational and experimental studies that addressed the focused question 'Do periodontal outcomes of buccally impacted maxillary canines that were surgically exposed and subsequently extruded and aligned using orthodontic alignment, differ from those of spontaneously erupted maxillary canines?' were included. DATA EXTRACTION: Study screening, selection and data extraction were performed independently by two authors, with disagreement resolved by a third reviewer. The risk of bias was assessed using the JBI Critical Appraisal Checklist and GRADE approach. RESULTS: A total of 857 citations were found and five studies were eligible for inclusion. Supragingival plaque accumulation and gingival inflammation were similar between impacted canines and their contralaterals in most studies. Meta-analyses revealed no significant differences in keratinised tissue width (prospective studies: MD = -0.28, 95% confidence interval [CI] = -1.13-0.56, I² = 78%; retrospective studies: MD = 0.61, 95% CI = -1.51-2.72, I² = 94%). However, a meta-analysis of prospective studies showed slightly greater mean probing depth for impacted canines compared to their contralateral canines (prospective studies: MD = 0.16, 95% CI = 0.04-0.28, I² = 0%). The evidence certainty for keratinised tissue width and probing depth outcomes was low. CONCLUSION: Surgically exposed and orthodontically aligned buccally impacted canines have slightly greater probing depths, potential bone loss and increased clinical crown length, compared to their counterparts. However, these small differences (<1 mm) are unlikely to be clinically significant.