How successful is the CatBoost classifier in diagnosing different dental anomalies in patients via sella turcica and vertebral morphologic alteration?

BACKGROUND: To investigate how successfully the classification of patients with and without dental anomalies was achieved through four experiments involving different dental anomalies. METHODS: Lateral cephalometric radiographs (LCRs) from 526 individuals aged between 14 and 22 years were included. Four experiments involving different dental anomalies were created. Experiment 1 included the total dental anomaly group and control group (CG). Experiment 2 only had dental agenesis and a CG. Experiment 3 consisted of only palatally impacted canines and the CG. Experiment 4 comprised patients with various dental defects (transposition, hypodontia, agenesis-palatally affected canine, peg-shaped laterally, hyperdontia) and the CG. Twelve sella measurements and assessments of the ponticulus posticus and posterior arch deficiency were given as input. The target was to distinguish between anomalies and controls. The CatBoost algorithm was applied to classify patients with and without dental anomalies. RESULTS: In order from lowest to highest, the predictive accuracies of the experiments were as follows: experiment 4 < experiment 2 < experiment 3 < experiment 1. The sella area (SA) (mm2) was the most important variable in experiment 1. The most significant variable in prediction model of experiment 2 was sella height posterior (SHP) (mm). Sella area (SA) (mm2) was again the most relevant variable in experiment 3. The most important variable in experiment 4 was sella height median (SHM) (mm). CONCLUSIONS: Every prediction model from the four experiments prioritized different variables. These findings may suggest that related research should focus on specific traits from a diagnostic perspective.

Association between molar-incisor hypomineralisation and dental anomalies.

BACKGROUND: Common etiological factors have been reported in the development of molar-incisor hypomineralisation (MIH) and dental anomalies (DA). AIM: To assess the association between MIH and DAs. DESIGN: A cross-sectional study was performed to evaluate the presence of MIH and other six DAs in a sample of 415 pretreatment records from patients aged 9-18 years. Statistical analyses were performed using the chi-squared and Fisher's exact tests, and logistic regressions. RESULTS: There was statistically significant association between the prevalence of DAs and MIH (CI: 1.43-2.43, φ-coefficient: 0.204, PR: 1.87). Higher percentage of tooth agenesis (CI: 1.37-1.68, φ-coefficient: 0.271, PR: 1.50), maxillary premolar agenesis (CI: 1.70-3.65, φ-coefficient: 0.125, PR: 2.49), mandibular second premolar agenesis (CI: 1.68-3.16, φ-coefficient: 0.172, PR: 2.30) and distoangulation of the mandibular second premolars (CI: 1.31-3.47, φ-coefficient: 0.103, PR: 2.13) was observed among children who had MIH-affected teeth. Individuals with MIH had a 2.95 times greater chance of having DAs (R2 = .153). The number of patients with DAs was higher when the first molar showed severe defects (OR = 4.47; R2 = .149). CONCLUSION: There is a weak association between MIH and DAs. Patients with severe MIH lesions have a slightly higher risk of presenting DAs.

Globe-shaped central incisors in a patient with otodental syndrome.

Hearing impairments and dental anomalies are found in many genetic syndromes. Otodental syndrome is a rare combination of hearing loss and the presence of a pathognomonic dental phenotype known as globodontia, in which the tooth exhibits an abnormal globe shape. There is no histologic evidence of structural anomalies in the enamel, dentin, or pulp. This report describes the case of a 12-year-old boy who had hearing loss and 2 supernumerary globe-shaped teeth in the sites of the permanent maxillary central incisors. The diagnosis of otodental syndrome was established based on the clinical, radiographic, and histologic features, but other conditions, including dens evaginatus, talon cusp, dens invaginatus, and compound odontoma, should be included in the differential diagnosis. Dental treatment consisted of the extraction of both anomalous teeth, allowing spontaneous eruption of the impacted permanent central incisors. Early diagnosis of otodental syndrome permits a multidisciplinary approach to prevent other pathologic conditions, reduce functional damage, and avoid social problems.

Multidisciplinary approach to multiple dental anomalies in pediatric patients: a case report with 4-year follow-up.

The objective of this article is to report the clinical case and 4-year follow-up of a 5-year-old child with multiple dental anomalies, emphasizing the importance of early diagnosis and use of combined pediatric surgery and orthodontic approaches. A 5-year-old boy, accompanied by his mother, sought dental care for dental caries and tooth pain. Clinical and radiographic examinations revealed active caries, a supernumerary primary tooth in the region of the mandibular right second premolar, and severe ankylosis of the primary mandibular right second molar. The treatment plan involved extraction of the supernumerary tooth as well as sectioning and extraction of the ankylosed molar. When the patient was 6 years old, the permanent mandibular right first molar showed signs of an altered eruptive process, and orthodontic treatment was initiated. A unilateral band-and-loop space maintainer with coil springs designed to move the permanent first molar was placed on the primary first molar. A new panoramic radiograph, obtained when the patient was aged 7 years, suggested the presence of an odontoma in the apical region of the primary maxillary right canine. Surgical removal and histopathologic examination of the lesion confirmed that it was a developing odontoma. After surgery, due to occlusal anomalies that included transverse maxillary deficiency, deep overbite, and midline deviation, the patient underwent rapid maxillary expansion therapy with a Haas-type appliance. When the patient was 8 years old, orthodontic treatment continued with a removable palatal Hawley expander and a orthodontic mandibular lingual arch. Currently, at the age of 9 years, the child is still undergoing fixed orthodontic treatment after surgical exposure of the impacted permanent maxillary right canine and bonding of an orthodontic attachment to enable traction. A multidisciplinary approach to the management of dental anomalies promotes a favorable prognosis and ensures comprehensive treatment of young patients.

Root canal morphology of permanent mandibular anterior teeth in a Pakistani population: A cone beam computed tomography assessment.

Objective: To investigate the incidence of accessory canals and the variation in root canal morphology of permanent mandibular incisors and canines in Pakistani population using Cone Beam Computed Tomography (CBCT). Methods: A cross-sectional study was conducted in University College of Dentistry, The University of Lahore, Pakistan after getting institutional ethical permission from January 2020 to September 2022. The data included records of 111 patients consisting of 444 permanent mandibular incisors and 222 permanent mandibular canines. Accessory root, root canals and Vertucci canal configuration for each tooth was recorded. Data analysis was done using SPSS v20. Descriptive statistics were calculated for each anatomical parameter. Chi-square test was applied to determine association of gender with the presence of accessory roots and root canals. Results: Among the 111 records evaluated, 48.6% were males and 51.4% were females. No accessory root was found in the central and lateral incisors. However, an accessory root was found in 4.9% of the canines. The incidence of accessory canals in the central incisors, lateral incisors and canines was 18.9%, 25.2% and 10.4% respectively. The most common canal configuration in teeth with accessory canals was Type-III, followed by Type-II and Type-V. Conclusion: None of the central or lateral incisor showed accessory root while it was detected in 4.9% canines. The frequency of accessory root canal was found to be 18.9%, 25.2% and 10.4% in central incisors, lateral incisors and canines respectively. The most common canal configuration was Type-I, followed by Type-III and Type-II. Type-V, VI and VII were less common.

Comprehensive Long-Term Outcomes Following Mandibular Distraction Osteogenesis.

OBJECTIVE: To describe long-term outcomes and complications following mandibular distraction osteogenesis (MDO) in a diverse patient cohort. DESIGN: Cross-sectional study. SETTING: Single tertiary-care pediatric center. PATIENTS: Forty-eight patients previously undergoing MDO with minimum 4-year follow-up. MAIN OUTCOME MEASURES: Respiratory outcomes, feeding patterns, dental development, motor/sensory nerve function, temporo-mandibular joint function, and postsurgical scarring. RESULTS: Forty-six patients with a median age of 7 years were evaluated. Of 20 nonsyndromic patients, none required additional airway procedures, none required continuous positive airway pressure (CPAP) during sleep, and 19 (95%) fed exclusively by mouth. Among 26 syndromic patients, 7 (27%) required CPAP and 8 (31%) were tube fed. Permanent first molar differences were seen in the majority of subjects; patterns of damage interfering with function were more common in syndromic (13/28, 46%) compared to nonsyndromic (5/24, 21%; P = .014) subjects. MDO prior to age two was associated with more frequent and worse dental damage (P = .001). Inferior alveolar nerve and marginal mandibular nerve function were fully intact in 37 (80%) and 39 (85%) of patients, respectively. Three patients (6%), all with associated genetic syndromes, demonstrated severe nerve impairment. By the Vancouver scar scale, ≥ 80% of surgical scars were rated in the most favorable category for each quality assessed. Temporomandibular joint dysfunction was rare. CONCLUSIONS: MDO shows highly favorable long-term respiratory, feeding, nerve, and scar outcomes in nonsyndromic patients, although permanent molar changes not precluding tooth viability are commonly seen. Patients with associated syndromes demonstrate respiratory and feeding benefits, but higher rates of dental and nerve abnormalities.

Mandibular second premolar distoangulation: a longitudinal follow-up from the mixed to the permanent dentition.

OBJECTIVE: The aim of this study was to assess the frequency of mandibular second premolar (MnP2) distoangulation among orthodontic patients and the angular changes after a longitudinal follow-up. METHODS: The sample was collected from the orthodontic records of 865 patients. The distoangulation group was composed of 42 patients (mean age 9.29 ±â€…1.24 years, 16 male, 26 female) with distoangulation of MnP2. The control group was composed of 32 patients (mean age 9.38 ±â€…1.10 years, 15 male, and 17 female) without distoangulation of MnP2. Panoramic radiographs taken in the mixed (T1) and the early permanent dentition (T2) were analyzed in both groups. Longitudinal angular changes (distal angle θ and premolar-molar angle γ), degree of root formation, second premolar depth, and prevalence of associated dental anomalies were analyzed. Intergroup comparison was performed with Mann-Whitney, t-tests, and chi-square tests (P < 0.05). RESULTS: The prevalence of MnP2 distoangulation in the mixed dentition was 4.85%. The distoangulation group showed a smaller initial distal angle (59.34o ±â€…8.41) when compared to control group (79.88o ±â€…7.60). The spontaneous eruption of the MnP2 with distoangulation was observed in 76.57% of the sample. MnP2 distoangulation was significantly associated with agenesis of its antimere, small maxillary lateral incisors, and deciduous molar infraocclusion. LIMITATIONS: Severe cases of MnP2 distoangulation were absent in this study. CONCLUSIONS: The frequency of MnP2 distoangulation among orthodontic patients was 4.85%. Mild to moderate distoangulated Mnp2 spontaneously uprighted from the mixed to the permanent dentition. Small lateral incisors, second premolar agenesis, and infraocclusion of deciduous molar were frequently found in cases with MnP2 distoangulation.

Challenges of a two-phase orthodontic treatment of a mandibular lateral incisor-canine transposition and a maxillary palatally displaced canine: A case report.

INTRODUCTION: The management of eruption disturbances in orthodontics may be challenging and requires a careful diagnosis and treatment planning. This case report discusses the challenges of a two-phase orthodontic treatment of a patient presenting with a dental eruption pattern anomaly. PATIENT CONCERNS: A 10-year-old boy was presented with no complaints for a routine orthodontic evaluation during mixed dentition. PRIMARY DIAGNOSES: The patient was diagnosed with a skeletal Class I malocclusion with unilateral posterior crossbite, incomplete mandibular lateral incisor-canine transposition and a unilateral maxillary ectopic canine. INTERVENTIONS: Phase 1 started with rapid maxillary expansion to correct maxillary constriction and the ectopic eruption of the right maxillary canine. In the mandibular arch, phase 1 included the extraction of the left primary lateral incisor and canine, alignment of the left permanent lateral incisor and orthodontic traction of the left permanent canine. The duration of phase 1 was 14 months. Phase 2 involved a comprehensive course of orthodontic treatment and started when the patient was aged 13 years. This phase lasted 18 months. RESULTS: An adequate dental occlusion was obtained, and the treatment results were stable after an 18-month follow-up. CONCLUSION: In this case, the early diagnosis of the dental anomalies was valuable as it allowed an early intervention to be undertaken, which resulted in overall treatment simplification and potentially minimised the adverse effects. This case report reinforces the importance of a careful follow-up during mixed dentition.

Prevalence and association of dental anomalies and tooth decay in Italian childhood cancer survivors.

The aim of this cross-sectional study was to assess the prevalence and severity of dental anomalies according to age at cancer treatment and type of antineoplastic protocol using the Modified Dental Defect Index (MDDI) and to explore the association between MDDI scores and caries experience in Italian childhood cancer survivors (CCS). A total of 88 CCSs (age range 6-20 years) treated with chemotherapy and/or radiotherapy for malignant diseases and in remission from at least 2 years were consecutively recruited from March 2019 to July 2022. All participants were examined for dental caries and enamel defects in the permanent dentition according to the decayed-missing-filled teeth (DMFT) index and the Aine rating scale. Dental abnormalities were diagnosed using panoramic radiographs and graded for severity according to the MDDI. The MDDI values were categorized as normal (MDDI, 0), moderately abnormal (1 ≤ MDDI < 16), and severely abnormal (MDDI ≥16). None of the enrolled children had normal MDDI score. MDDI and DMFT values were higher in CCSs submitted to cancer treatment before 5 years of age, while no statistically significant association was found with anticancer protocols. A significant positive correlation emerged between DMFT and MDDI values (p < 0.001). CCSs with moderately abnormal disturbances had statistically significant lower DMFT scores (p < 0.001) than those with severe dental abnormalities. These findings suggest that children in remission from malignant diseases with MDDI values ≥16 have poorer dental health and should be strictly monitored by dental specialists.

Is Aberrant DNA Methylation a Key Factor in Molar Incisor Hypomineralization?

Molar incisor hypomineralization (MIH) is a qualitative disturbance of the enamel of the permanent molars and/or incisors. Its etiology is not clearly defined but is connected with different factors occurring before and after birth. It remains difficult to identify a single factor or group of factors, and the problem is further complicated by various overlapping mechanisms. In this study, we attempted to determine whether DNA methylation-an epigenetic mechanism-plays a key role in the etiology of MIH. We collected the epithelium of the oral mucosa from children with MIH and healthy individuals and analyzed its global DNA methylation level in each child using a 5-mC DNA ELISA kit after DNA isolation. There was no statistically significant difference between the global DNA methylation levels in the study and control groups. Then, we also analyzed the associations of the DNA methylation levels with different prenatal, perinatal, and postnatal factors, using appropriate statistical methods. Factors such as number of pregnancies, number of births, type of delivery, varicella infection (under 3 years old), and high fever (under 3 years old) were significantly important. This work can be seen as the first step towards further studies of the epigenetic background of the MIH etiology.

Oral and dental late effects in long-term survivors of childhood embryonal brain tumors.

PURPOSE: To investigate oral and dental late effects in survivors of childhood brain tumors medulloblastoma (MB) and central nervous system supratentorial primitive neuroectodermal tumor (CNS-PNET). METHODS: This cross-sectional study assessed oral and dental late effects in MB/CNS-PNET survivors treated before 20 years of age, and with a minimum of 2 years since treatment. Participants went through an oral and radiographic examination. We assessed oral status using the decayed-missing-filled index (DMFT), oral dryness, maximum mouth opening (MMO), fungal infection, and registration of dental developmental disturbances (DDD) in the form of hypodontia, microdontia, and enamel hypoplasia. RESULTS: The 46 participants' mean age at enrolment was 27 ± 12.8 years and at treatment 8.5 ± 5.2 years, and the mean time since treatment was 18.9 ± 12 years. Over a third (35%) of survivors had reduced mouth opening (mean 29.3 ± 5.6 mm (range 16-35)). A significantly lower MMO was found in individuals treated ≤ 5 years compared to survivors treated > 5 years (p = 0.021). One or more DDD were registered in 30.4% of the survivors, with a significantly higher prevalence in individuals treated ≤ 5 years (p < 0.001). Hypodontia was the most prevalent type of DDD. There was no difference in DMFT score in relation to age at treatment. Oral dryness was not frequently reported or observed in these survivors. CONCLUSION: Survivors of childhood MB/CNS-PNET are at risk of oral and dental late effects including reduced mouth opening and DDD. The risk is highest in survivors treated before the age of 5.

Tooth abnormalities associated with non-syndromic cleft lip and palate: systematic review and meta-analysis.

OBJECTIVE: To evaluate the association between orofacial clefts (OFC) and tooth abnormalities (TA). METHODS: We searched PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and BBO, and in the gray literature and selected observational studies that evaluated the association between TA and OFC. The risk of bias was analyzed using the Newcastle-Ottawa Scale. A random-effects meta-analysis was performed comparing the presence and absence of OFC, cleft type-cleft palate (CP) and cleft lip with or without palate (CL/P)-and cleft laterality-unilateral and bilateral. The certainty of evidence was evaluated using the GRADE approach. RESULTS: A total of 99 studies were included in the qualitative analysis, and 37 were included in the meta-analysis. Only four studies were classified as low risk of bias. Significant associations were observed between the presence of OFC and tooth agenesis (OR = 19.46; 95%CI = 4.99-75.96), supernumerary teeth (OR = 4.04; 95%CI = 1.26-12.99), developmental defects of enamel (OR = 3.15; 95%CI = 1.28-7.80), microdontia (OR = 15.57; 95%CI = 1.06-228.51), and taurodontism (OR = 1.74; 95%CI = 1.74-2.86). Individuals with CP had a lower frequency of supernumerary teeth (OR = 0.22; 95%CI = 0.08-0.64), peg-shaped tooth (OR = 0.31; 95%CI = 0.12-0.80), and morphological TA (OR = 0.13; 95%CI = 0.04-0.45) than individuals with CL/P. No TA was significantly associated with cleft laterality (p > 0.05). The quality of the evidence was very low in all analyses. CONCLUSION: Individuals with OFC had a higher frequency of TA than those without OFC. Individuals with CP had a lower frequency of TA than individuals with CL/P. No TA was associated to cleft laterality. CLINICAL RELEVANCE: Help to identify the treatment needs of individuals affected by OFC, improving the services provided to this population.

Root Curvature in Non-Syndromic Oral Clefts: A Case-Control Study in a Brazilian Population.

OBJECTIVE: This study assesses the degree of root curvature in patients with non-syndromic cleft lip and/or palate (NSCL/P). DESIGN: Retrospective. Case-control study. SETTING: Root curvature was assessed in lower premolars and molars in 800 panoramic radiographs: 400 from patients with cleft and 400 from healthy control individuals. Root curvature was classified according to its angulation, as well as its apical, medial, or coronal localization. RESULTS: The frequency of mild curvature in the NSCL/P group compared to the control group was higher in premolars especially in the left second premolar in cleft palate (OR: 6.91; 95% CI: 3.23-14.77; P < .0001). The frequency of moderate curvature in molars was significantly higher in the cleft group, with the highest risk in the right first molar in the cleft lip group (OR: 2.74; 95% CI: 1.67-4.52; P < .0001). Inclination was more frequently observed in the apical third of the root in the group with cleft, whereas for the control group, the curvature was more frequent in the medial third. In patients with cleft, the OR of curvature in the apical third was significant in premolars (left lower second premolar: Cleft lip, OR: 1.91; 95% CI: 1.04-3.52; P = .03; right lower second premolar: Cleft lip, OR: 1.91, 95% CI: 1.04-3.50; P = .03, cleft lip and palate, OR: 1.75; 95% CI: 1.12-2.73; P = .01). CONCLUSION: The results of the current study indicate differences in root curvature in patients with non-syndromic cleft lip and/or palate, which should be considered during the dental treatment planning of patients.

Novel variants in critical domains of ATP8A2 and expansion of clinical spectrum.

ATP8A2 is a P4-ATPase that flips phosphatidylserine across membranes to generate and maintain transmembrane phospholipid asymmetry. Loss-of-function variants cause severe neurodegenerative and developmental disorders. We have identified three ATP8A2 variants in unrelated Iranian families that cause intellectual disability, dystonia, below-average head circumference, mild optic atrophy, and developmental delay. Additionally, all the affected individuals displayed tooth abnormalities associated with defects in teeth development. Two variants (p.Asp825His and p.Met438Val) reside in critical functional domains of ATP8A2. These variants express at very low levels and lack ATPase activity. Inhibitor studies indicate that these variants are misfolded and degraded by the cellular proteasome. We conclude that Asp825, which coordinates with the Mg2+ ion within the ATP binding site, and Met438 are essential for the proper folding of ATP8A2 into a functional flippase. We also provide evidence on the association of tooth abnormalities with defects in ATP8A2, thereby expanding the clinical spectrum of the associated disease.

Abnormalities in Tooth Formation after Early Bisphosphonate Treatment in Children with Osteogenesis Imperfecta.

Treatment with intravenous bisphosphonate (BP) in children and adolescents with osteogenesis imperfecta (OI) started in Sweden in 1991. No human studies on the role of BP therapy in development of disturbances in tooth mineralization or tooth morphology have been published. The study cohort comprised 219 individuals who were divided into four groups: group 1, BP treatment onset before 2 years of age (n = 22); group 2, BP treatment onset between 2 and 6 years of age (n = 20); group 3, BP treatment onset between 6 and 10 years of age (n = 13); and a control group of patients with OI who had not received BP therapy (n = 164). The chi-square test was used in between-group comparisons of the prevalence of tooth agenesis. The prevalence of tooth agenesis was significantly higher in children who began BP treatment before the age of 2 years (group 1; 59%,) compared to the controls (10%; p < 0.001) and to children who had begun BP therapy between ages 2 and 6 years (group 2; 10%; p = 0.009) or between ages 6 and 10 years (group 3; 8%; p = 0.003). Different types of disturbances in the enamel formation were seen in 52 premolars, where 51 were seen in those who began BP treatment before the age of 2 years. To conclude, starting BP treatment before the age of 2 years increases the risk of abnormalities in tooth formation manifesting as morphological aberrations, tooth agenesis, and enamel defects.

Rare dental developmental disturbance in primary and permanent teeth following trauma prior to tooth eruption: Case report.

Traumatic dental injuries are highly prevalent among preschool children. When occurring at a very young age (prior to the eruption of the primary teeth), such trauma can disturb the normal development of the permanent dentition and, more rarely, affect the primary dentition. This report describes a case of a patient who suffered dentoalveolar trauma at six months of age that caused rare developmental problems in the primary dentition, such as impaction, dilacerations, hypoplasia, and odontoma. Imaging revealed that alterations also occurred in the permanent dentition. This report demonstrates that dentoalveolar trauma prior to complete development of the dentition and even before the eruption of the primary teeth can lead to highly uncommon abnormalities in the primary dentition. Moreover, there may be repercussions in the permanent dentition when the germs of these teeth are injured by the intraosseous displacement of primary teeth.

Enamel of Premolars whose Predecessors Presented Rupture of the Follicle Bone Crypt from Periapical Infections.

OBJECTIVE: To observe if dental alterations in premolars are associated with the rupture of the follicle bone crypt caused by a periapical lesion in the predecessor molars. STUDY DESIGN: This is a cross-sectional study. Data collection consisted of the analysis of medical records, a socioeconomic questionnaire, and dental clinical examination. Records from patients with a history of a radiographically visible periapical lesion in lower primary molars submitted to pulp therapy or extraction from a university dental clinic were selected. Successor premolars were clinically evaluated for the presence of enamel development defects, shape alterations, and eruption deviations. The descriptive analysis of data was performed, and Fisher's exact tests, linear trend chi-square, and the Student's t-test were applied. RESULTS: Forty-eight permanent teeth were from 36 patients were evaluated in this study, and 20 (41.7%) of the 48 examined premolars showed a radiographic image suggestive of the rupture of the bone crypt. Rupture of the follicle bone crypt was not associated with the occurrence of enamel alterations in premolars (p = 0.418). An association between dental alterations and age over six years at the time of intervention was observed (p = 0.043). CONCLUSION: The presence of enamel alterations of premolars was not associated with the rupture of the follicle bone crypt caused by a periapical lesion in predecessor molars.

Elements of morphology: Standard terminology for the teeth and classifying genetic dental disorders.

Dental anomalies occur frequently in a number of genetic disorders and act as major signs in diagnosing these disorders. We present definitions of the most common dental signs and propose a classification usable as a diagnostic tool by dentists, clinical geneticists, and other health care providers. The definitions are part of the series Elements of Morphology and have been established after careful discussions within an international group of experienced dentists and geneticists. The classification system was elaborated in the French collaborative network "TÊTECOU" and the affiliated O-Rares reference/competence centers. The classification includes isolated and syndromic disorders with oral and dental anomalies, to which causative genes and main extraoral signs and symptoms are added. A systematic literature analysis yielded 408 entities of which a causal gene has been identified in 79%. We classified dental disorders in eight groups: dental agenesis, supernumerary teeth, dental size and/or shape, enamel, dentin, dental eruption, periodontal and gingival, and tumor-like anomalies. We aim the classification to act as a shared reference for clinical and epidemiological studies. We welcome critical evaluations of the definitions and classification and will regularly update the classification for newly recognized conditions.

Second premolar agenesis as a subclinical phenotype of isolated cleft palate.

OBJECTIVE: To compare the prevalence of dental anomalies in patients with isolated cleft palate with or without hypodontia of the second premolar. SETTING AND SAMPLE POPULATION: A total of 653 patients with isolated cleft palate aged 8-12 years were divided into two groups: G1-subjects without hypodontia of second premolar (n = 546) and G2-subjects with hypodontia of at least one-second premolar (n = 107). The control group consisted of 107 non-cleft orthodontic patients. MATERIALS & METHODS: Panoramic and periapical radiographs and dental casts were used to analyze the presence of dental anomalies. Intergroup comparisons were performed using the chi-square test complemented by Proportion test and Bonferroni test. RESULTS: G2 presented higher prevalence of hypodontia of other permanent teeth compared to G1 and control. Ectopic eruption of the maxillary canine and tooth transposition were more frequent in patients with a cleft compared to patients without a cleft, without statistical differences. Deciduous molar infra-occlusion and second premolar disto-angulation were less prevalent in G1 and G2 compared to the control group. G2 showed a higher prevalence of complete cleft palate than G1. CONCLUSION: Patients with cleft palate and second premolar agenesis showed increased prevalence of tooth agenesis and palatally displaced canines.

Dental anomaly patterns associated with tooth agenesis.

OBJECTIVE: The objective of this study is to evaluate the relationship between tooth agenesis and the occurrence of other dental anomalies in children and adolescents. MATERIAL AND METHODS: Panoramic radiographs of 195 subjects with tooth agenesis, except for the third molar, were retrospectively examined and compared with a non-agenesis control group of 600 subjects. Their ages ranged from 7 to 15 years. Panoramic and periapical radiographs were used to analyze the presence of other associated dental anomalies. The occurrences of these anomalies were compared with those in the non-agenesis group. RESULTS: Subjects with tooth agenesis showed a significantly higher prevalence of a small maxillary lateral incisor (17.7%), distoangulation of the mandibular second premolar (6.5%), delayed development of a permanent tooth (10.8%), and hypo-occlusion of a primary molar (11.8%). In contrast, the prevalence of a supernumerary tooth was higher in the control group, and no difference was observed in the prevalence of ectopic eruption of a first molar. According to the agenesis area, microdontia of the maxillary lateral incisors occurred more often in patients with anterior or premolar agenesis than in the molar agenesis groups. Distoangulation of the mandibular second premolars, delayed tooth development, and hypo-occlusion of the primary molars were associated with premolar tooth agenesis. CONCLUSIONS: A small maxillary lateral incisor, distoangulation of the mandibular second premolar, delayed development of a permanent tooth, and hypo-occlusion of a primary molar were frequently associated with tooth agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies.