Tooth pattern, development, and replacement in the yellow catfish, Pelteobagrus fulvidraco.

Studies of teleost teeth are important for understanding the evolution and mechanisms of tooth development, replacement, and regeneration. Here, we used gross specimens, microcomputed tomography, and histological analysis to characterize tooth structure, development, and resorption patterns in adult Pelteobagrus fulvidraco. The oral and pharyngeal teeth are villiform and conical. Multiple rows of dentition are densely distributed and the tooth germ is derived from the epithelium. P. fulvidraco exhibits a discontinuous and non-permanent dental lamina. Epithelial cells surround the teeth and are separated into distinct tooth units by mesenchymal tissue. Tooth development is completed in the form of independent tooth units. P. fulvidraco does not undergo simultaneous tooth replacement. Based on tooth development and resorption status, five forms of teeth are present in adult P. fulvidraco: developing tooth germs, accompanied by relatively immature tooth germs; mature and well-mineralized tooth accompanied by one tooth germ; teeth that have begun resorption, but not completely fractured; fractured teeth with only residual attachment to the underlying bone; and teeth that are completely resorbed and detached. Seven biological stages of a tooth in P. fulvidraco were also described.

Supernumerary teeth in patients with cleft lip and palate: the tooth germs do not separate.

INTRODUCTION: Supernumerary teeth in cases of cleft lip and palate do not result from the division of normal germs before the formation of hard tissue. Deciduous and permanent teeth odontogenesis begins after the face has formed, either with or without the cleft. DISCUSSION: The most acceptable hypothesis to enable understanding of the presence of supernumerary teeth on one or both sides of the cleft palate is hyperactivity of the dental lamina in its walls. This hyperactivity, with the formation of more tooth germs, must be attributed to mediators and genes related to tooth formation, under strong influence of local epigenetic factors, whose developmental environment was affected by the presence of the cleft. CONCLUSION: The current concepts of embryology no longer support the fusion of embryonic processes for the formation of the face, but rather the leveling of the grooves between them. All human teeth have a dual embryonic origin, as they are composed of ectoderm and mesenchyme/ectomesenchyme, but this does not make it easy for them to be duplicated to form supernumerary teeth.

Supernumerary teeth in patients with cleft lip and palate: the tooth germs do not separate

ABSTRACT Introduction: Supernumerary teeth in cases of cleft lip and palate do not result from the division of normal germs before the formation of hard tissue. Deciduous and permanent teeth odontogenesis begins after the face has formed, either with or without the cleft. Discussion: The most acceptable hypothesis to enable understanding of the presence of supernumerary teeth on one or both sides of the cleft palate is hyperactivity of the dental lamina in its walls. This hyperactivity, with the formation of more tooth germs, must be attributed to mediators and genes related to tooth formation, under strong influence of local epigenetic factors, whose developmental environment was affected by the presence of the cleft. Conclusion: The current concepts of embryology no longer support the fusion of embryonic processes for the formation of the face, but rather the leveling of the grooves between them. All human teeth have a dual embryonic origin, as they are composed of ectoderm and mesenchyme/ectomesenchyme, but this does not make it easy for them to be duplicated to form supernumerary teeth.

RESUMO Introdução: Os dentes extranumerários nas fissuras labiopalatinas não são resultado da divisão dos germes normais antes da formação do tecido duro. A odontogênese dos decíduos e permanentes inicia-se depois de formada a face, com ou sem fissuras. Discussão: A hipótese mais plausível para compreender a presença dos dentes extranumerários em um ou nos dois lados da fissura labiopalatina é a hiperatividade da lâmina dentária em suas paredes. Essa hiperatividade, com formação de mais germes dentários, deve ser atribuída aos mediadores e genes relacionados à formação dos dentes, sob forte influência de fatores epigenéticos locais, cujo ambiente de desenvolvimento foi afetado pela presença da fissura. Conclusão: Os conceitos atuais da embriologia não fundamentam mais a fusão de processos embrionários para a formação da face, e sim o nivelamento dos sulcos entre eles. Todos os dentes humanos têm uma dupla origem embrionária, pois se compõem de ectoderma e mesênquima/ectomesênquima, mas isso não facilita sua duplicação para formar dentes extranumerários.

Evaluation of gubernacular tract with cone beam computed tomography in impacted supernumerary teeth

The gubernacular canal or gubernacular tract is filled by the gubernacular cord, which includes fibrous connective tissue containing peripheral nerves, blood and lymphatic ducts besides the epithelial cells from the fragmented dental laminae, including epithelial growth factor. The purpose of this study was to evaluate the gubernacular tract in unerupted supernumerary teeth by cone beam computed tomography. Sixty-four unerupted supernumerary teeth were selected from 44 patients (21 females, 23 males, 12-68 years). Gubernacular tract characteristics were evaluated in five different groups: No alteration, bending of gubernacular tract, contraction of gubernacular tract, obliterations of gubernacular tract, difference between erupted direction. Unerupted supernumerary teeth were classified according to their position. The presence and characteristics of the gubernacular tract in the supernumerary teeth were evaluated by cone beam computed tomography. In our study, the frequency of the gubernacular tract was found to be 31.7%. There was no significant difference between the presence of gubernacular tract and gender, age and gubernacular tract characteristics. It was found that gubernacular tract characteristics did not change according to gender, quadrant, age and unerupted positions. Cone beam computed tomography is an efficient method for the evaluation of the gubernacular tract in unerupted supernumerary teeth. Conducting these studies in larger populations will provide more detailed information about the prognosis of impacted supernumerary teeth

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Comparación de los métodos de Willems I y Willems II en la estimación forense de la edad en niños venezolanos / Comparison of the Willems I and Willems II methods for forensic age estimation in Venezuelan children

INTRODUCCIÓN: El presente trabajo tuvo como objetivo comparar los métodos de Willems et al. (WI y WII) en la estimación forense de la edad en niños venezolanos. MATERIAL Y MÉTODOS: Esta investigación fue de tipo retrospectiva y observacional. Se emplearon 516 ortopantomografías de individuos de ambos sexos (6-18 años), se asignaron los estadios de maduración dental descritos por Demirjian et al. en los 7 dientes inferiores izquierdos, para luego determinar la edad dental (ED) mediante WI y WII. Se calculó la diferencia de media entre la edad cronológica (EC) y la ED estimada mediante una prueba «t» de Student para muestras relacionadas. RESULTADOS: Para el total de la muestra se observó la subestimación de la edad por ambos métodos (0,17+/-1,75 años), siendo la diferencia EC-ED estadísticamente significativa (p = 0,04). Considerando todos los grupos de edad, WII mostró la menor diferencia EC-ED (0,05 años+/-1,40) en el sexo femenino, mientras que para el masculino se encontró menor diferencia para WI (0,04+/-0,54 años). En una submuestra hasta los 16 años se evidenció una subestimación de la edad en el sexo femenino para WI (0,03+/-1,23 años) y una sobreestimación para WII (-0,18+/-1,24 años), en el sexo masculino ambos métodos sobreestimaron la edad (W1=-0,21+/-1,17; WII=-0,06+/-1,20 años). CONCLUSIONES: La precisión de los métodos varió de acuerdo al sexo y grupo de edad, sin embargo, ambos resultaron aplicables a la muestra estudiada

INTRODUCTION: The purpose of this study was to compare the methods of Willems et al., (WI and WII) in estimating the forensic age in Venezuelan children. MATERIAL AND METHODS: A retrospective and observational study was performed on 516 orthopantomographs of individuals of both genders (6-18 years) in order to evaluate the stages of dental maturation described by Demirjian et al. Using the dental age (DA) in the seven left inferior teeth, DA was calculated using the WI and WII methods. The mean difference between the chronological age (CA) and DA was calculated using a paired-sample t-Test. RESULTS: The under-estimation of age by both methods (0.17+/-1.75 years) was observed, with the CA-DA difference being statistically significant (P=.04). Considering all age groups, WII showed the smallest difference between CA-DA (0.05+/-1.40 years) in girls, while a smaller difference was found for WI (0.04+/-0.54 years)for boys. In a subsample up to the age of 16, there was an under-estimation of age in females for WI (0.03+/-1.23 years) and an over-estimation for WII (-0.18+/-1.24 years). In the males both methods over-estimated the age (W1=-0.21+/-1.17 years, WII=-0.06+/-1.20 years). CONCLUSIONS: The accuracy of the methods varied according to gender and age group: however, both were applicable to the studied sample

¿Cuál es su diagnóstico? / What is your diagnosis?

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Reliability of prenatal detection of X-linked hypohidrotic ectodermal dysplasia by tooth germ sonography.

OBJECTIVE: In X-linked hypohidrotic ectodermal dysplasia (XLHED), dysfunction of ectodysplasin A1 (EDA1) due to EDA mutations results in malformation of hair, teeth, and sweat glands. Hypohidrosis, which can cause life-threatening hyperthermia, is amenable to intrauterine therapy with recombinant EDA1. This study aimed at evaluating tooth germ sonography as a noninvasive means to identify affected fetuses in pregnant carrier women. METHODS: Sonography, performed at 10 study sites between gestational weeks 18 and 28, led to the diagnosis of XLHED if fewer than six tooth germs were detected in mandible or maxilla. The assessment was verified postnatally by EDA sequencing and/or clinical findings. Estimated fetal weights and postnatal weight gain of boys with XLHED were assessed using appropriate growth charts. RESULTS: In 19 of 38 sonographic examinations (23 male and 13 female fetuses), XLHED was detected prenatally. The prenatal diagnosis proved to be correct in 37 cases; one affected male fetus was missed. Specificity and positive predictive value were both 100%. Tooth counts obtained by clinical examination corresponded well with findings on panoramic radiographs. We observed no weight deficits of subjects with XLHED in utero but occasionally during infancy. CONCLUSION: Tooth germ sonography is highly specific and reliable in detecting XLHED prenatally.

Bioengineered Tooth Buds Exhibit Features of Natural Tooth Buds.

Tooth loss is a significant health issue currently affecting millions of people worldwide. Artificial dental implants, the current gold standard tooth replacement therapy, do not exhibit many properties of natural teeth and can be associated with complications leading to implant failure. Here we propose bioengineered tooth buds as a superior alternative tooth replacement therapy. We describe improved methods to create highly cellularized bioengineered tooth bud constructs that formed hallmark features that resemble natural tooth buds such as the dental epithelial stem cell niche, enamel knot signaling centers, transient amplifying cells, and mineralized dental tissue formation. These constructs were composed of postnatal dental cells encapsulated within a hydrogel material that were implanted subcutaneously into immunocompromised rats. To our knowledge, this is the first report describing the use of postnatal dental cells to create bioengineered tooth buds that exhibit evidence of these features of natural tooth development. We propose future bioengineered tooth buds as a promising, clinically relevant tooth replacement therapy.

Prenatal Correction of X-Linked Hypohidrotic Ectodermal Dysplasia.

Genetic deficiency of ectodysplasin A (EDA) causes X-linked hypohidrotic ectodermal dysplasia (XLHED), in which the development of sweat glands is irreversibly impaired, an condition that can lead to life-threatening hyperthermia. We observed normal development of mouse fetuses with Eda mutations after they had been exposed in utero to a recombinant protein that includes the receptor-binding domain of EDA. We administered this protein intraamniotically to two affected human twins at gestational weeks 26 and 31 and to a single affected human fetus at gestational week 26; the infants, born in week 33 (twins) and week 39 (singleton), were able to sweat normally, and XLHED-related illness had not developed by 14 to 22 months of age. (Funded by Edimer Pharmaceuticals and others.).

The characteristics of adjacent anatomy of mandibular third molar germs: a CBCT study to assess the risk of extraction.

This study aims to investigate the characteristics of adjacent anatomy of mandibular third molar germs (MTMGs). Three hundred Chinese patients aged 12 to 17 years old who received cone-beam computed tomography (CBCT) were enrolled. The continuity of cortical outline of inferior alveolar canals (IACs) in the region of MTMGs, the integrity of lingual bone cortex and the relationship between hard tissue part of MTMGs and IACs were investigated by observing CBCT data via the NNT viewer software. The age, degree of dental development, gender and location were recorded as variables. The associations between different variables and the observed data were analysed. The possibilities of disrupted cortical outline of IACs or the hard tissue part of MTMGs contacting IACs were significantly lower in 12 or 13 age groups, lower in Nolla stage ≤ 6. Males were significantly less than females in the incidence of disrupted cortical outline of IACs. As to the perforation of lingual bone cortex, no significant differences were observed in gender, ages, location or development stages. According to the CBCT images, anatomical factors contributed the lest to the risk of inferior alveolar nerve and lingual nerve injury in the 12 to 13 age group during removing the MTMG removal.

Two-Dimensional Identification of Fetal Tooth Germs.

OBJECTIVE: To demonstrate the efficiency and applicability of two-dimensional ultrasonography in the identification of tooth germs and in the assessment of potential pathology. DESIGN: Observational, descriptive, cross-sectional study. SETTING: Prenatal Diagnosis Unit of Centro Hospitalar de Vila Nova de Gaia / Espinho-Empresa Pública in Portugal. PATIENTS: A total of 157 white pregnant women (median age, 32 years; range, 14 to 47 years) undergoing routine ultrasound exams. MAIN OUTCOME MEASURE(S): Description of the fetal tooth germs, as visualized by two-dimensional ultrasonography, including results from prior fetal biometry and detailed screening for malformations. RESULTS: In the first trimester group, ultrasonography identified 10 tooth germs in the maxilla and 10 tooth germs in the mandible in all fetuses except for one who presented eight maxillary tooth germs. This case was associated with a chromosomal abnormality (trisomy 13) with a bilateral cleft palate. In the second and third trimesters group, ultrasonography identified a larger range of tooth germs: 81.2% of fetuses showed 10 tooth germs in the maxilla and 85.0% of fetuses had 10 tooth germs in the mandible. Hypodontia was more prevalent in the maxilla than in the mandible, which led us to use qualitative two-dimensional ultrasonography to analyze the possible association between hypodontia and other variables such as fetal pathology, markers, head, nuchal, face, and spine. CONCLUSIONS: We recommend using this method as the first exam to evaluate fetal morphology and also to help establish accurate diagnosis of abnormalities in pregnancy.

Determination of the mesio-distal tooth width via 3D imaging techniques with and without ionizing radiation: CBCT, MSCT, and µCT versus MRI.

Objective: The purpose of this study was to estimate the feasibility and accuracy of mesio-distal width measurements with magnetic resonance imaging (MRI) in comparison to conventional 3D imaging techniques [multi-slice CT (MSCT), cone-beam CT (CBCT), and µCT]. The measured values of the tooth widths were compared to each other to estimate the amount of radiation necessary to enable orthodontic diagnostics. Material and Methods: Two pig skulls were measured with MSCT, CBCT, µCT, and MRI. Three different judges were asked to determine the mesio-distal tooth width of 14 teeth in 2D tomographic images and in 3D segmented images via a virtual ruler in every imaging dataset. Results: Approximately 19% (27/140) of all test points in 2D tomographic slice images and 12% (17/140) of the test points in 3D segmented images showed a significant difference (P ≤ 0.05). The largest significant difference was 1.6mm (P < 0.001). There were fewer significant differences in the measurement of the tooth germs than in erupted teeth. Conclusions: Measurement of tooth width by MRI seems to be clinically equivalent to the conventional techniques (CBCT and MSCT). Tooth germs are better illustrated than erupted teeth on MRI. Three-dimensional segmented images offer only a slight advantage over 2D tomographic slice images. MRI, which avoids radiation, is particularly appealing in adolescents if these data can be corroborated in further studies.

Surgical Template to Minimize the Damage of Tooth Buds in Young Children With Mandibular Distraction Osteogenesis.

BACKGROUND: Mandibular distraction osteogenesis has become one of the most powerful reconstructive techniques for the treatment of mandibular deformities in young children. Damage to the tooth buds is often cited as a complication of it. The purpose of this study was to precisely design the osteotomy line and avoid the damage of tooth buds at the mandibular angle area with the help of surgical template. METHODS: Six patients aged from 6 to 10 years were selected in this study. Three-dimensional computed tomography data was put into Mimics software for preoperative planning the osteotomy line and the accurate placement of the distractor based on the exact position of tooth follicle. And then the surgical template was manufactured by a three-dimensional printer with rapid prototyping technique. The surgeons were guided to perform the osteotomy aided with the prefabricated template through an intraoral approach. Distraction began 7 days postoperation with a rate of 1 mm/d and the distractor was removed after a 6 to 8 months consolidation period. The tooth buds were observed through radiographs that were performed at 5 time intervals: before distraction, at the end of latency, at the end of distraction, at the end of consolidation and 2 years of the postoperation to remove the distractor. RESULTS: The average follow-up time is 24 months. Facial appearance and occlusal plane of all the young patients were greatly improved without complications. From the radiological observation, the tooth buds was intact after the surgery and the second molar normally erupted after removing the distractor. CONCLUSIONS: The surgical template was considered to be helpful in improving the surgical accuracy and avoiding the tooth buds damage during mandibular distraction osteogenesis.

Cone-Beam Computed Tomography Study Of Crown Dilaceration With a Talon Cusp in an Unerupted Permanent Maxillary Tooth.

This article describes a rare case of crown dilaceration with a talon cusp in an unerupted permanent maxillary central incisor. Our patient was a 7-year-old boy with a history of trauma to his primary maxillary teeth (#51 and 52), at 3 years of age complaining of failure of eruption of tooth #11. Periapical radiography showed incomplete formation of tooth root #11 and more superior position of tooth bud #11 relative to tooth bud #12. A cone-beam computed tomography was ordered, which revealed crown dilaceration with a talon cusp in tooth bud #11. The patient was scheduled for follow-up at 6 months.

A spatial association between odontomas and the gubernaculum tracts.

OBJECTIVES: The purpose of this study was to identify the spatial relationship and/or association between odontomas and the gubernaculum tract or the dental sac and the characteristic findings for radiographic diagnosis of odontomas. STUDY DESIGN: The visualizations of the odontomas and the gubernaculum tract were retrospectively analyzed using cone beam computed tomography or multidetector computed tomography. RESULTS: Most of odontomas were within the gubernaculum tract or dental sac of unerupted permanent teeth on computed tomography. In some odontomas, the gubernaculum tract existed as a well-defined low density tract extending from the top of odontomas on computed tomography. CONCLUSIONS: A close spatial relationship and/or association between odontomas and the gubernaculum tract or dental sac on computed tomography may be used as one of the criteria for radiographic diagnosis of odontomas. Development of odontomas may be associated with the gubernaculum tract or dental sac of unerupted permanent teeth.

Fast and Early Mandibular Osteodistraction: The Long-Term Follow-Up of Mandibular Distraction Osteogenesis on Teeth Position.

Pierre Robin Sequence is a congenital pathology defined by the triad micrognathia, glossoptosis and often a U-shaped cleft of soft palate. Newborns affected by airways obstruction may necessitate more invasive options: tongue-lip adhesion, tracheostomy and mandibular distraction osteogenesis. The authors analyzed the effect of fast and early mandibular osteodistraction on deciduous dental development in patients affected by Pierre Robin Sequence. Analysis of the patients treated for severe form was performed by a team composed by maxillofacial surgeons and dentists. Five patients were included for the analysis: before and long term clinical and radiological assessments were considered. All patients underwent fast and early mandibular osteodistraction; two years follow up computed tomography and panorex reconstructions showed bone consolidation, 33 of 35 teeth analyzed before ostedistraction are present after distraction protocol; no positional changes were detected at the follow up analysis either deciduous teeth and molar permanent buds. No deformities regarding molar buds were detected. In conclusion external mandibular distractor devices have been associated with dental injuries and facial scaring. Even though, the dental complications identified can not be unambiguously connected to the external distractor devices.

Detection and imaging characteristics of the gubernacular tract in children on cone beam and multidetector computed tomography.

PURPOSE: To elucidate the appearance and imaging characteristics of the gubernacular tract (GT) during the growth stage of children. Furthermore, this study evaluated the significance of the appearance of the GT. STUDY DESIGN: The visualizations of the GT were retrospectively analyzed by using panoramic radiographs and computed tomography (CT) in children. RESULTS: In patients with normal eruption who had unerupted permanent teeth, except maxillary central supernumerary teeth, the GT was clearly visualized as a well-defined low-density tract on CT but not on panoramic radiographs. In patients with obstructive eruption, including impaction, the GT was deformed and not visible on CT. CONCLUSIONS: This paper describes the frequency of detection and appearance of the GT in unerupted teeth. Preliminary data suggest that any alteration to the GT may be used to predict abnormal eruption of permanent teeth.

Prenatal ultrasound and postmortem histologic evaluation of tooth germs: an observational, transversal study.

INTRODUCTION: Hypodontia is the most frequent developmental anomaly of the orofacial complex, and its detection in prenatal ultrasound may indicate the presence of congenital malformations, genetic syndromes and chromosomal abnormalities. To date, only a few studies have evaluated the histological relationship of human tooth germs identified by two-dimensional (2D) ultrasonography. In order to analyze whether two-dimensional ultrasonography of tooth germs may be successfully used for identifying genetic syndromes, prenatal ultrasound images of fetal tooth germs obtained from a Portuguese population sample were compared with histological images obtained from fetal autopsies. METHODS: Observational, descriptive, transversal study. The study protocol followed the ethical principles outlined by the Helsinki Declaration and was approved by the Ethics Committee of the School of Dental Medicine, University of Porto (FMDUP, Porto, Portugal) and of the Centro Hospitalar de Vila Nova de Gaia/Espinho (CHVNG/EPE, Porto, Portugal) as well as by the CGC Genetics Embryofetal Pathology Laboratory. Eighty-five fetuses examined by prenatal ultrasound screening from May 2011 to August 2012 had an indication for autopsy following spontaneous fetal death or medical termination of pregnancy. Of the 85 fetuses, 37 (43.5%) were randomly selected for tooth germ evaluation by routine histopathological analysis. Fetuses who were up to 30 weeks of gestation, and whose histological pieces were not representative of all maxillary tooth germs was excluded. Twenty four fetus between the 13(th) and 30(th) weeks of gestation fulfilled the parameters to autopsy. RESULTS: Twenty four fetuses were submitted to histological evaluation and were determined the exact number, morphology, and mineralization of their tooth germs. All tooth germs were identifiable with ultrasonography as early as the 13(th) week of gestation. Of the fetuses autopsied, 41.7% had hypodontia (29.1% maxillary hypodontia and 20.9% mandibular hypodontia). CONCLUSIONS: This results indicate that prenatal ultrasound is a reliable method for detecting of hypodontia an early gestational ages. Further studies with larger samples are needed to confirm these results.

Age-related changes in the location of the mandibular and mental foramen in children with Mongoloid skeletal pattern.

AIM: To observe age-related changes in the locations of mandibular foramen (MF) and mental foramen (mf) using dental panoramic tomographs (DPTs). METHODS: Ethical approval was obtained for this retrospective study. Location of MF was related to the ramus and occlusal plane, while mf to (i) erupted primary molars (ii) unerupted premolar tooth germs (iii) vertical height at the body of the mandible. RESULTS: One hundred and sixty-five DPTs were obtained from children with Mongoloid skeletal pattern. The ethnic composition was 112 Malays and 53 Chinese children (Willems dental age = 5.2-16.0 years). At the horizontal plane, MF remained constant at middle mid-quadrant of the ramus (88 %) and vertical plane; 68 % located below and 40 % above the occlusal plane. At age 9 years and above, there was a significant tendency for MF to be located at the level of occlusal plane. The most common location of mf was related to (i) erupted primary molars, mesial root of second primary molar (38 %); (ii) unerupted premolars tooth germs, between the apices of first and second premolar (44 %); and (iii) proportional vertical height to the mandible, middle third (52 %). At age 11 years and above, a significant tendency of mf to be located at the middle third of the body of mandible was observed. CONCLUSIONS: With advancing age and growth, the position of MF remained constant at the ramus with tendency to move from below to at the level of occlusal plane, while mf moved distally and inferiorly.

Association between mesially displaced maxillary first premolars and early displaced maxillary canines.

AIM: To evaluate the association between the mesially displaced maxillary first premolar (MDP) and the early displacement of the adjacent permanent canine (EDC) before their eruption. MATERIALS AND METHODS: A sample of 1247 subjects in the intermediate mixed dentition stage was assessed for the presence of MDP and EDC. All subjects were divided into two groups: MDP group and noMDP group. For each subject two angular measurements (premolar-occlusal plane η and л premolar-midline angles) were analysed on panoramic radiographs. The chi-square test with Yates correction was performed to compare the prevalence rate of EDC in MDP (MDP-EDC) and noMDP groups. The statistical comparisons for the values of η and л angles between MDP vs noMDP, MDP vs MDP-EDC, and noMDP vs MDP-EDC groups were performed by means of ANOVA with Bonferroni correction. RESULTS: The prevalence rate of EDC in the MDP group was significantly greater than in the noMDP group (66% vs. 12.1%). MDP-EDC group showed a significantly larger л angle than in the MDP group resulting in an increased mesial inclination of displaced premolars. CONCLUSION: MDP can be considered a dental anomaly associated to maxillary canine displacement.