Dentition Stage Research Articles

Comparison between stone and digital cast measurements in mixed dentition : Validity, reliability, reproducibility, and objectivity.

PurposeTo assess the validity, reliability, reproducibility, and objectivity of measurements on stone casts of patients with mixed dentitions compared to measurements on three-dimensional (3D) digital models derived from surface scans of the stone casts.MethodsPairs of stone casts of 30 young patients in their mixed dentition stage were included and processed into 3D digital models using an intraoral scanner (iTero Element 2; Align Technology, San Jose, CA, USA). Then an experienced and an inexperienced examiner independently performed measurements of five defined parameters, each in triplicate, both on the digital models with analysis software (OnyxCeph3™; Image Instruments, Chemnitz, Germany) and on the original casts with a vernier calliper. Paired t-tests were used for validity and interexaminer objectivity, Pearson correlation coefficients for intermethod reliability, and intraclass correlation coefficients (ICCs) for reproducibility testing.ResultsSignificant (p < 0.05) intermethod differences were identified for four parameters, but only the differences for overbite and intermolar distance exceeded the threshold of clinical relevance (≥ 0.5 mm). Intermethod reliability was high and method error invariably lower for the digital measurements and for the experienced examiner. Both examiners achieved ICCs > 0.907 with both methods. Interexaminer variation involved significant differences for all parameters but one (intermolar distance) on the stone casts and for three parameters on the digital models.ConclusionMeasurements performed on digital models of mixed dentitions can yield clinically acceptable outcomes with OnyxCeph3™ software. Both the digital and the analogue measurements were highly reproducible and reliable. Objectivity of the measurements could not be confirmed, as operator experience did make a difference.

Extensive Gingivoperiosteoplasty Versus Secondary Alveolar Bone Grafting in Patients With Complete Bilateral Cleft Lip and Palate During the Mixed Dentition Period: A Retrospective Outcome Analysis.

The concept of gingivoperiosteoplasty (GPP) in the mixed dentition stage as compared with secondary alveolar bone grafting (ABG) in management of alveolar cleft has not been much discussed upon. The authors present the experience with extensive GPP and ABG in the mixed dentition stage in complete bilateral alveolar cleft cases. A retrospective review of nonsyndromic patients with complete bilateral alveolar cleft operated on with either GPP or ABG (iliac crest) in the mixed dentition stage with at least 1-year follow-up was performed. Dental occlusal radiographs were evaluated for level of bone gain using Bergland and Witherow scales. Statistical evaluation of clinical success and procedure-related complications was conducted using χ2 test and odds ratio. Twenty-four patients in the GPP group and 20 in the ABG group were comparatively studied. Clinical success rate as indicated by Bergland scales I and II (87.5% in GPP vs 82.5% in ABG; P = 0.731), complication rate (20.83% in GPP vs 30% in ABG; P = 0.484), and status of canine eruption showed no significant differences in clinical outcomes in both groups. The technique of extensive GPP as described by authors shows equal efficacy to secondary ABG for management of bilateral alveolar clefts during the mixed dentition period.

Assessing the Clinical Consequences of Untreated Caries in 8- to 10-Year-Old Children with Pufa Index

Aim: The aim of this study is to assess the oral health conditions of 8- to 10-year-old students in the mixed dentition stage in Erzurum, Turkey, by determining their dental caries’ status and the soft tissue damages by untreated caries. Materials and Methods: The study was carried out in two randomly selected schools in the residential areas populated predominantly by families with mid-and-low socioeconomic levels. A total of 586 children, 275 girls, and 365 boys with a mean age of 8.95 ± 0.8 participated in the study. Number of decayed, missing due to caries, and filled teeth in the permanent dentition/number of decayed and filled teeth in the primary dentition (DMFT/dft) and visible pulpal involvement (P/p), ulceration caused by dislocated tooth fragments (U/u), fistula (F/f) and abscess (A/a) (PUFA)/pufa indices are included in the clinical examination section of the study. Obtained data were analyzed with SPSS (IBM Corp. 2013, IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY). Results: Our research revealed a DMFT score of 2.43 ± 1.7, dft 4.12 ± 2.7, pufa 0.75 ±1.2, PUFA 0.05± 0.24, a caries frequency of 96.1, PUFA/pufa frequency of 40.9, and untreated caries PUFA/pufa ratio was found as 13.3%. A significant difference with positive correlation was found between d and pufa scores ( P &lt; .01). Increasing DMFT, decayed, missing, and filled surfaces (DMFS) in the permanent dentition, and decreasing dft, decayed, and filled surfaces (dfs) in the primary dentition, and pufa scores with the age increment were found to be significant ( P &lt; .05). Conclusion: The frequency of soft tissue damage associated with untreated caries, caries index scores, and frequency of dental caries was found to be quite high in the study population consisting of children belonging to families with similar socioeconomic status.

Dental arch changes after anterior open bite treatment in the mixed dentition produced by miniscrew-supported palatal crib vs conventional fixed palatal crib.

To evaluate the dental arch changes produced by the miniscrew-supported palatal crib (MSPC) and the conventional fixed palatal crib (CFPC) after the treatment of patients with anterior open bite (AOB) attributed to the tongue-thrusting habit in the mixed dentition stage. A total of 26 children aged 8 to 11 years with an AOB were randomly distributed into two equal groups; the MSPC group was treated using a palatal crib supported by two miniscrews inserted paramedially, whereas the CFPC group was treated using a conventional fixed palatal crib soldered to bands. Digital models were obtained pretreatment and after a follow-up duration of 9 months. The MSPC group included 12 participants (9 girls and 3 boys; mean age, 9.4 ± 0.75 years), and the CFPC group included 12 participants (10 girls and 2 boys; mean age, 9.0 ± 0.73 years). The amount of AOB closure was similar in both groups: 3.97 ± 1.44 mm in the MSPC group and 3.97 ± 0.89 mm in the CFPC group. There was significant mesial movement of the maxillary first molar in the CFPC (-1.42 ± 0.99 mm) compared with the MSPC group (-0.53 ± 0.32 mm). Both appliances resulted in similar improvement in the amount of AOB closure. There was significantly more mesial movement of the maxillary first molars in the CFPC group compared with the MSPC group.

Conventional Versus Digital Assessment of Dental Arches' Perimeters in Mixed Dentition

The advances of digital technologies in dentistry have made significant changes in orthodontic diagnosis and treatment planning. Digital three-dimensional models are commonly used to perform dental arch and teeth measurements through intra-oral scanners and software. This study aimed to test the reliability of two softwares in measuring dental arch perimeters compared to the conventional one. Twenty-four pairs of stone models belonging to Iraqi children at the mixed dentition stage were selected and scanned with a laser scanner. Maxillary and mandibular dental arch perimeters were measured as a sum of four segments from central incisor to canine and from canine to the first molar on both sides using digital calipers (on stone models) Ortho Analyzer, and the Geomagic Design X software(on scanned models). Reliability has been evaluated by intra-class correlation coefficient and Bland-Altman plots, while systematic and proportional biases were evaluated by paired sample t-test and linear regression analysis, respectively. Non-significant differences were obtained for most measurements with good to excellent reliability. Digital technologies, including model scanning and software measurements can be used with adequate precision and reliability to assess dental arch perimeters as with stone models and conventional measurements with dental vernier.

Adverse pregnancy outcomes and occlusal traits in the primary dentition: A prospective cohort (BRISA).

This study aimed to analyse the relationship between adverse pregnancy outcomes (APO) and occlusal traits in the primary dentition, checking for different mediation paths. Children evaluated at birth (T1), between 12 and 24months (T2), and between 24 and 36months (T3) were included. Two hundred and seventeen children who participated in T1 and T2 were randomly selected to perform the occlusion examination. This is a prospective cohort study (BRISA). The theoretical model was tested by structural equation modelling (SEM), estimating standardized coefficients (Coeff.) (α=0.05). The primary exposure was APO-a latent variable manifested from three health problems at birth: low birthweight (LBW), pre-term birth (PTB) and intrauterine growth restriction (IUGR), evaluated in T1. The outcomes were four different occlusal traits assessed in T3: overjet, anterior and posterior crossbite, and crowding. Each outcome's direct and indirect effects were tested, mediated by growth, breathing, breastfeeding, and pacifier use. There was no direct association between APO and any of the outcomes: overjet (Coeff.=-0.163, P=.241), anterior crossbite (Coeff.=-0.696, P=.065), posterior crossbite (Coeff.=-0.087, P=.589) and crowding (Coeff.=0.400, P=.423). The indirect (total and specifics) effects tested also showed no association (P>.05). However, APO was associated with lower child growth in all models; breastfeeding was associated with higher child growth in all models, and pacifier use was associated with overjet (Coeff.=0.184, P<.001) and posterior crossbite (Coeff.=0.373, P=.011). APO was not a risk factor for overjet, crossbite and crowding in an early stage of the primary dentition by direct and indirect pathways. However, growth has been lower in children with APO and higher in children breastfed. Also, the harmful effects of using a pacifier in dental occlusion are highlighted.

Correlation between Streptococcus mutans levels in dental plaque and saliva of children.

This study was designed to compare the levels of Streptococcus mutans (S. mutans) in saliva with those in occlusal plaque on posterior teeth at different stages of dentition, and to explore the correlation with caries experience to determine the most suitable source of S. mutans for research. Samples of saliva and occlusal plaque were collected from 83 patients (aged 3-17 years) over three months. S. mutans levels were determined by culture-based selective plating, morphological identification, and S.mutans-specific monoclonal antibody labeling. The mean age of the participants was 8.8 (±3.7) years, and 74.7% of them were Hispanic. Mean caries experience for children with primary, mixed, and permanent dentition was 5.2 (±4.7), 4.0 (±3.3), and 0.8 (±1.3), respectively. Children with primary and mixed dentition had a higher caries experience than children with permanent dentition (P < 0.01), despite having similar S. mutans levels and total bacteria. A positive correlation was observed between S. mutans levels in plaque and those in saliva, but not between S. mutans levels and caries experience. It was noteworthy that plaque samples harbored higher S. mutans levels (>105 CFU/mL) than saliva samples. Both plaque and saliva samples are useful sources for S. mutans isolation. S. mutans levels from both sources were not significantly correlated with caries experience, but occlusal plaque had greater sensitivity for quantification of high S. mutans levels.

Rates, Patterns and Prevalence of Mandibular Fractures in Children

Maxillofacial pediatric fractures are highly uncommon due to their unique characteristics of high elasticity, cartilaginous tissue, lack of pneumatization, evolutionary stages of dentition and other protective features. However, despite their rarity, pediatric facial fractures often seen by pediatric surgeons, plastic surgeons and in the emergency department. The mandible is the most commonly fractured pediatric facial bone. In this review, we will discuss the various patterns of mandibular fractures, their rates and prevalence in the pediatric population. An extensive search was conducted from various electronic databases such as PubMed, Medline Embase, Google Scholar and Cochrane Library to retrieve original researches and narrative reviews. The most common site to be fractured in the mandible is the condylar process, followed by the symphysis and the angle. Condylar process fractures are more common in younger children between the ages of 1 to 13 and angular fractures supersede during the teenage years. Mandibular fractures are also categorized based on the localization and number of fractures such as a single fracture, or multiple fracture both unilateral and bilateral. Further studies with larger sample sizes and specific age groups should be conducted to achieve more significant results.

Interceptive treatment of the aberrant labial frenulum in the transition dentition stage using 808nm diode laser

The aberrant labial frenulum is one of the etiological factors for midline diastema. Such frenulum needs timely detection and early intervention in transition dentition to intercept the developing midline diastema in growing children. A conservative and minimal-invasive approach should be considered for managing the abnormal frenulum in the pediatric age group. This article presents a clinical case report on the successful and effective treatment of aberrant maxillary labial frenulum in a 10-year-old pediatric patient using the diode laser of 808 nm wavelength without infiltrative local anesthesia and sutures. The follow-up evaluation demonstrated optimum healing without any complications. The patient demonstrated cooperation and satisfaction with the laser surgery and its excellent healing outcomes.

2 × 4 appliance in the mixed dentition stage: a scoping review of the evidence.

A great emphasis is currently given to the early correction of malocclusions to prevent further complications if left untreated. Interceptive orthodontics not only simplifies but also eliminates the need for later procedures. The 2 × 4 appliance is an orthodontic treatment modality applied during the mixed dentition period, particularly for malpositioned permanent upper incisors. This scoping review was aimed to examine the breadth and depth of the published literature on this clinical topic, as well as knowledge gaps, about this fixed appliance during mixed dentition, for the correction of incipient anterior malocclusions (incisor crowdings, midline diastemas, or crossbites). PubMed, Cochrane Library, Google Scholar, Dentistry & Oral Sciences Source, and two grey literature databases were explored; under a structured PICO question (Patient, Intervention, Comparison, Outcome) and eligibility criteria, for relevant clinical trials, observational studies, and case reports/series (in English or Spanish), using different searching terms. Titles and abstracts were screened. Full-text articles were critically reviewed for bias risk and a data charting table was constructed. 161 references were identified, after which 115 titles remained after removing duplicates. After the abstract screening, 18 potential full-text articles were reviewed. Finally, 16 studies were included, according to the performed critical appraisal. The 2 × 4 appliance is suitable for mixed dentition patients with mild or severe malocclusions, particularly when removable appliance usage is a critical problem.

Clinical Evaluation for Space Maintainer after Unilateral Loss of Primary First Molar in the Early Mixed Dentition Stage

Background and Objectives: Controversy exists regarding the need for a space maintainer after early unilateral loss of a primary first molar. This study aimed to assess the need for a space maintainer after unilateral loss of a primary first molar in the early mixed dentition period. Materials and Methods. In this cross-sectional study, fifty children between 6 and 8 years who had lost a primary first molar unilaterally later than 6 months ago were randomly selected. Midline deviation, molar and canine relationships at both sides, facial growth pattern, and the amount of space loss were all assessed. Data were analyzed using SPSS version 25 via the one-sample t-test, paired t-test, and linear regression (alpha = 0.05). Results. The mean amount of space loss was 1.36 ± 0.78 mm (1.32 mm in the maxilla and 1.40 mm in the mandible). Time since tooth extraction and facial pattern had significant correlations with space loss (P < 0.05). Conclusion. In this particular age group, it is imperative to precisely assess the related factors such as the facial pattern and time since tooth extraction to decide about the placement of a space maintainer for a prematurely lost primary first molar.

Orthodontic treatment for posterior crossbites.

Orthodontic treatment for posterior crossbites.

Distribution of congenitally missing teeth and treatment options for the lower second premolars in patients referred to special care

Objective The aim was to evaluate the distribution of congenitally missing teeth and the treatment provided for congenitally missing lower second premolars in an eleven-year cohort of patients referred to a publicly funded source of specialist care. Material and methods This was a retrospective, register-based cohort study. Search for patients referred to a publicly funded source of specialist care based on ICD10 diagnosis code K00.00 (partial anodontia) and treatment codes EBA00, EBA05, EBA10, EBA12, EBB10 and EBB20 during the period 1.1.2009–27.10.2019 yielded 232 patients (151 females, 81 males), of whom 218, born in 1941–2009, were eligible. Data collected from medical files were presented in the form of descriptive statistics and analysed using Fisher’s exact test. Results The 218 subjects possessed 876 congenitally missing teeth (males 307, females 569) (third molars excluded). The most common missing teeth were upper second premolars and lateral incisors, and lower second premolars and central incisors. No difference in laterality was found. Statistically significant associations were found between the choice of treatment and both the patient’s age at referral and the patient’s year of birth. Most common treatment for adult patients (age 18–56 years) was placement of an implant (67%), while autotransplantation (11%) was the preferred option for children at the mixed dentition stage (age 9–15 years). Conclusions The congenitally missing teeth most commonly involved in referrals of patients to publicly funded specialist care were lower second premolars. The most frequent treatment was insertion of an implant for adults and autotransplantation at the mixed dentition stage.

Multidisciplinary approach in the anterior open bite using a McNamara expander with palatal crib during mixed dentition stage: A case report

Open bite can be defined as an absence of occlusion, most frequently located in the anterior region of dental arches and its etiology is multifactorial. We present a clinical case of an 8 years and 10 months child presenting an anterior open bite (AOB) with transverse maxillary deficiency caused by tongue thrust during mixed dentition. The malocclusion was corrected by means of a McNamara expander with a palatal crib jointly with the association of speech therapy for tongue repositioning, and otolaryngology to treat adenoid hypertrophy due to its correlation with AOB. The multidisciplinary approach was effective in correcting the malocclusion with stable results after 2 years post-treatment.

Anterior crossbite correction in early mixed dentition stage using functional jaw orthopedics principles: a case report with two-years follow-up

A five-year-old and four-month-old male patient presented with Class I malocclusion, anterior crossbite (pseudo-class III) with an overbite, midline deviation to the left (5 mm), left unilateral chewing preference, and incisors in bi-retrusion with diastemas. Initial Bimler cephalometry showed negative anterior face angle (&lt; A), negative bone overjet (A’B’), mesoprosope biotype, negative suborbital facial index, microrhinic dysplasia, and reduced T-TM distance. Pre-treatment gnathostatic models revealed vertical asymmetry and increased left occlusal plane. After the initial assessment, we initiated the treatment with resin-composite planas direct tracks in the deciduous upper molar surface to lift the bite. The patient was oriented to perform right-side mastication movements using hyperboloid exercises. After one month, a new resin-composite lift was carried out in the lower deciduous molar occlusion surface. Planas direct tracks were built directly on the occlusal of the maxillary molars 64 and 65 to start centering the patient’s midline, which was deviated to the left, raising the bite, and increasing the vertical dimension. In the same dental appointment, we completed the right side on the occlusal of the teeth 54 and 55, to adjust the occlusion using 200 microns articulated paper. After a month, the patient returned to the dental office and resins were placed in the occlusal surface of teeth 74, 75, 84, and 85, completing the direct planas tracks and leaving the occlusal plane the most parallel to the Camper’s Plan. Direct planas tracks’ adjustments were made throughout the patient's treatment returns, with 200 microns articulated paper and selective wear. Hyperboloid (silicone-made accessory to stimulate the stomatognathic system) was used to perform chewing exercises on the right side and instructed to be performed before the main meals, for five minutes, encouraging chewing on the right side. The subsequent masticatory evaluation showed protrusive movements. To reduce this movement, planas direct tracks from canine-to-canine were prepared, correcting the anterior bite, and reducing the midline deviation to the left. Posteriorly, functional orthopedic treatment began with the Simões Network 3 (SN3) device, with Bimler’s upper dental arch not touching the incisors and an upper expander. Concomitantly, in the lower dental arch, we initiated the treatment with a Hawley dental appliance against the cervical third of lower incisors and a W-shaped lingual retainer. The SN3 device was built in a laboratory specialized in maxillary functional orthopedics, after molding the patient with alginate and wax bite registration. After 12 months of treatment, the patient presented a centralized midline, had permanent lower incisors, erupting upper central incisors, and adequate bilateral chewing. After 24 months of treatment, the patient presented physiological limits with the contact of the upper central incisors in a determined area with 2 mm overjet, centralized midline, efficient bilateral chewing, and balanced maxillomandibular growth. Post-treatment Bimler cephalometry showed a negative anterior face angle (&lt; A), positive bone overjet (A’B’), mesoprosope biotype, increased T-TM distance. In addition, Planas’ gnathostatic models evidenced a symmetric occlusal plane. In conclusion, functional jaw orthopedics approaches can significantly contribute to the inhibitory and excitatory stimulation of the mandible to the maxilla. Furthermore, functional orthopedics might establish an appropriate development of the stomatognathic system in patients with mixed dentition.

Open bite and atypical swallowing: orthodontic treatment, speech therapy or both? A literature review.

The cause-effect relationship between anterior open bite and atypical swallowing, two frequently associated conditions, is currently not completely understood. These conditions are often accompanied by speech disorders and represent a problem for both young patients and untreated adult patients. Treatment of these complex cases may be orthodontic, logopedic therapy or both. The purpose of this review is to compare the various types of treatment to determine their effectiveness in improving skeletal condition, normalisation of muscle activity, and temporal stability. The present systematic review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyzes (PRISMA) guidelines. In order to find the most appropriate articles for inclusion, an electronic and manual search was performed using PubMed and The Cochrane Library on May 23, 2021. No language restrictions or time limits were applied. Only human studies describing cases of patients in the developmental stage of dentition, i.e., deciduous dentition or mixed dentition with an anterior open bite related to a type of swallowing with tongue interposition between the arches, undergoing three different types of treatment (orthodontic only, myofunctional/logopedic only, combined) were included. The most effective treatment in cases of anterior open bite associated with atypical swallowing is a combination of the traditional orthodontic therapy and myofunctional therapy. Further studies are needed to devise an effective and universal logopaedic protocol to be followed in these cases.

Dento-skeletal effects of myofunctional appliance on patients with class II div 1 in mixed dentition stage: A cephalometric study

Myofunctional appliances are commonly used to stimulating positively the masticatory and tongue muscle activity, altering the posture of the mandible to a more forward position. These appliances could be effective in treating the Class II, Division 1 in the mixed dentition stage. The purpose of the clinical study was to evaluate the effects of Multi-P as a prefabricated functional appliance on the dento-skeletal structure in patients with Class II, Division 1 in the mixed dentition stage. This clinical study consisted of 18 pediatric patients (mean age 9.97 ± 1.36 years) with Class II Division 1 malocclusion. The Multi-P appliance was used in the treatment of all patients. Pre- and post-treatment cephalometric radiographs were evaluated to analyze the changes in dento-skeletal dimensions during the treatment period. When the pre-and post-treatment cephalometrics were compared, it was found that there were insignificant differences for the SNB°, SN-GoGn°, and Co-Gn distance (p ≥ 0.05). It was observed that the Go-Gn (p = 0.03) and SN (p = 0.033) distances remarkably increased, After the treatment, significant increases were observed in IMPA (p = 0.001) and ANB° (p = 0.001), and a significant decrease was found in U1-FH° (p = 0.023). Also, a significant reduction in the overjet was recorded in the patients (p = 0.000). The average treatment time was found to be 2.94 ± 0.70 years. Based on our results, it can be concluded that the Multi-P prefabricated myofunctional appliance for Class II, Division 1 malocclusion has mostly dentoalveolar effects without significant skeletal effects in the mixed dentition stage.

Effects of Gender and Age in Mandibular Leeway Space for Taiwanese Children.

Purpose: Leeway space is clinically crucial in pediatric dentistry because it is utilized to resolve tooth crowding and allow the first molars to drift mesially to establish a Class I molar relationship in the later stages of mixed dentition. This study investigated leeway space in the mixed dentition of Taiwanese children of different sexes and ages. Materials and Methods: The digital panoramic dental films of 182 lower arches of 119 boys and 63 girls aged 5–10 years were analyzed in this retrospective study. The mesiodistal crown widths of the primary canines and first and second molars and the permanent canines and first and second premolars were measured using medical imaging software. Differences in leeway space were statistically analyzed. Results: The average leeway space was 1.29 ± 1.48 mm on each side of the lower arch. The leeway space of children aged 5–6 years was significantly greater than that of children aged 7–8 years. No gender difference in crown width was discovered, except with regard to the primary first molar. Although no gender difference in leeway space was observed, permanent teeth affected leeway space more for girls than for boys. Conclusion: In Taiwanese children, although leeway space does not differ by sex, age affects leeway space. However, permanent tooth size has an influence on the leeway space of girls.

Seven-year follow-up of a patient with hereditary gingival fibromatosis treated with a multidisciplinary approach: case report

BackgroundHereditary gingival fibromatosis (HGF) is rare in clinical practice, and the long-term results of the combined orthodontic-periodontal treatment of HGF are rarely reported.Case presentationThis study reports for the first time the results of seven years of follow-up in a seven-year-old girl with HGF. The diagnosis was confirmed by clinical signs, family history and histopathological examination. First, periodontal scaling and oral hygiene reinforcement were performed regularly in the mixed dentition stage. Next, gingivoplasty was performed on the permanent dentition. Two months after the surgery, treatment with fixed orthodontic appliances was conducted. The teeth were polished on a monthly basis, and oral hygiene was reinforced to control gingival enlargement. Gingival hypertrophy recurred slightly, and gingivectomies were performed in the months following the start of orthodontic treatment. Follow-up was performed for 24 months with orthodontic retention, and gingival enlargement remained stable after the combined treatment.ConclusionsThe risk of gingival hyperplasia recurrence during and after orthodontic treatment is high, but satisfying long-term outcomes can be achieved with gingivectomy, malocclusion correction, and regular follow-up maintenance.

Prevalência de mordida aberta anterior em escolares de Porto Alegre

It was studied the open bite prevalence at four different steps of human dentition by epidemiological research in the school population in Porto Alegre. The open bite prevalence was bigger in the temporary dentition (38,11%) than in permanent or mixed dentition. ln the young permanent dentition the prevalence was 8,09% and 4,35% in the permanent one. It was verified by comparative study of the four evolution stages of human dentition, the great reduction of open bite prevalence from temporary to permanent dentition.