Crowded Dentition Research Articles

Is bracket bonding with guided bonding devices accurate enough for crowded dentition?

This research aimed to study whether bracket bonding using guided bonding devices (GBDs) is accurate enough for crowded dentitions in vitro. Fifteen three-dimensionally (3D) printed resin model sets were included and divided into three groups: mild, moderate, and severe crowding. The resin models were scanned and virtually bonded with brackets. Corresponding GBDs were generated and 3D printed. Subsequently, the brackets were bonded to the resin models on adental mannequin using the GBDs. The models with bonded brackets were scanned, and comparisons were made between the positions of the actually bonded and the planned ones to evaluate possible deviations. There was no immediate bonding failure in any group. The bonding duration tended to increase with crowding severity (P > 0.05). Almost all linear and angular deviations in all groups were below 0.5 mm and 2°, respectively, and no statistically significant difference was found among the different crowding degrees (P > 0.05). In all groups, the brackets tended to deviate lingually and had buccal crown torque. Brackets in the groups with mild and severe crowding showed atendency for mesiobuccal rotation. GBDs provide high bracket bonding accuracy for dentitions with different crowding degrees and, thus, could hopefully be applied to uncrowded and crowded dentitions alike.

Optimization of three-dimensional printing parameters for orthodontic applications.

To determine the impact of build orientation, increased layer thickness, and dental crowding on the trueness of three-dimensional (3D)-printed models, and to evaluate how these parameters affect the fit of thermoformed appliances. Ninety-six dental models were printed horizontally and vertically on the building platform using different 3D-printing technologies: (1) a stereolithography (SLA) printer with layer thicknesses of 160 μm and 300 μm and (2) a digital light processing (DLP) printer with layer thicknesses of 100 μm and 200 μm. Each printed model was digitalized and superimposed on the corresponding source file using 3D rendering software, and deviations were quantified by the root mean square values. Subsequently, a total of 32 thermoformed appliances were fabricated on top of the most accurate 3D-printed models, and their fit was evaluated by digital superimposition and inspection by three blinded orthodontists. Paired t-tests were used to analyze the data. Significant differences (P < .05) between printing technologies used were identified for models printed horizontally, with the SLA system achieving better trueness, especially in crowded dentitions. No significant differences between technology were found when models were printed vertically. The highest values of deviation were recorded in appliances fabricated on top of DLP-printed models. The results of the qualitative evaluation indicated that appliances fabricated on top of SLA models outperformed the DLP-modeled appliances. Three-dimensional printing with increased layer height seems to produce accurate working models for orthodontic applications.

Correlation of the Stature with Arch and Chord Dimensions in Young Subjects using Carrea's Index- An Anthropometric Study.

Forensic identifications have utilized the height or stature of an individual in their field. Teeth and dentition can act as reliable tools to estimate the stature in cases where the only skull is presented as evidence. The Carrea's index assesses the stature in a subject from the lower anterior teeth dimensions. The present study was aimed to judge the reliability of Carrea's index in Indian subjects. From 80 subjects who were undergraduate students, plaster models were made and each was assessed individually making 160 hemiarches. These hemiarches were divided based on the teeth alignment into normal, diastema, and crowded forms. This was followed by measurement with a vernier caliper into chord and arch. In both genders, the difference seen was statistically significant between dental arch types concerning various alignments with 95.23% and 83.75% success for males and females in normal dentition and 92.30% and 85.71% in crowded dentition. Also, a significant difference was seen for the type of arch with P ≤ 0.001 and 0.003, respectively. Lesser success was seen for spacing in both the genders and arches. The present study concludes that Carrea's index is a dependable and efficient tool for estimating height in subjects having arches with crowded and normal dentition which is functional for both the gender on the left and right side of the dental arches. However, in hemiarches with diastema, this method is not reliable.

Prevalence and Influencing Factors of Mixed Dentition Malocclusion in Children Aged 6-12 Years in Jinzhou, China.

To investigate the prevalence, clinical manifestations and related risk factors of malocclusion in schoolchildren of Jinzhou City, China. A total of 2162 children aged 6-12 years were randomly selected from various districts of Jinzhou. Conventional clinical examination was performed by stomatologists, and the results were described based on different clinical manifestations of malocclusion and individual normal occlusion. Further, a questionnaire survey completed by children's parents or guardians provided the demographic data, lifestyle, and oral habits. The distribution of individual normal occlusion and malocclusion was documented in percentage, and Pearson's Χ2 was used for two-factor analysis. The data were statistically analysed using SPSS software (version 25.0) with a significance level of α = 0.05. A total of 1129 boys and 1033 girls were included in this study, i.e. 52.2% and 47.8% of the total number of children, respectively. The prevalence of malocclusion in children aged 6-12 years old in Jinzhou was 67.9%, of which crowded dentition was the most common form, with a prevalence of 71.8%, followed by deep overbite, anterior crossbite, dental spacing, deep overjet, anterior edge-to-edge occlusion, and anterior open bite. In the logistic regression model, the results showed that BMI index had little effect on the occurrence of malocclusion (p > 0.05), while dental caries, bad oral habits, retained primary teeth, and a low labial frenum were all related to the occurrence of malocclusion (p < 0.05). Moreover, the higher frequency and duration of bad oral habits were associated with a higher likelihood of malocclusion. The prevalence of malocclusion in children aged 6-12 years in Jinzhou is high. In addition, bad oral habits (such as lip biting, tongue thrusting, biting/gnawing objects, unilateral chin supporting, and unilateral mastication) and other related risk factors (such as dental caries, mouth breathing, retention of primary teeth, and low labial frenum, etc) were associated with malocclusion.

Assessment of Dental Crowding Occurring in Mixed Dentition in Maxillary and Mandibular Arches Based on Tooth Size-Arch Length Relationships and Certain Cephalometric Parameters.

The aim of the study is to find indicators of crowding in primary and mixed dentition that may lead to occurrence of dental crowding in future dentition using dental measurements. A sample of 300 children was selected and divided into two groups based on their age primary dentition and mixed dentition. Dental arch impressions were made and casts were poured. The study was then divided into two phases for assessment of degree of crowding by Little's irregularity index (LII) and by measurement of tooth size-arch length discrepancies. Appropriate statistical analysis was used to assess the correlation of measurements in crowded and noncrowded groups. It was found that Little's index is less dependable as an indicator of anterior crowding. In the primary dentition, there is significant difference in inter-canine width between lower noncrowded and crowded dentition. In the mixed dentition, there is significant difference in Intermolar width between upper noncrowded and crowded dentition and in sum of incisors between noncrowded and crowded dentition in both the arches. Little's index is not a reliable indicator of crowding in both primary and mixed dentition. Inter-canine width of lower arch can be considered as an indicator of crowding in primary dentition. The intermolar width of upper arch, sum of incisors in upper and lower arch and the intercanine width of upper and lower arch can be considered indicators of crowding in the mixed dentition. Kandakkeel FN, Nagar P, Saseendran A, et al. Assessment of Dental Crowding occurring in Mixed Dentition in Maxillary and Mandibular Arches based on Tooth Size-Arch Length Relationships and Certain Cephalometric Parameters. Int J Clin Pediatr Dent 2023;16(2):357-362.

Moebius Syndrome: An Updated Review of Literature.

Moebius Syndrome, is a rare, non-progressive congenital neuropathological syndrome characterized primarily by the underdevelopment of the facial (CN VII) and abducens nerve (CN VI). Other features of Moebius Syndrome include facial nerve paresis, ophthalmoplegias, orthodontic deficiencies (including crowded dentition, swollen and hyperplastic gingiva, dental calculus, etc.), musculoskeletal abnormalities, and impaired mental function. Due to the rarity of the disorder, very few case studies have been reported in the literature. This article summarizes the significant features of the disease according to commonalities in reported cases, along with several newly recognized features cited in recent literature. We have explored the different diagnostic criteria and the newly recognized imaging modalities that may be used. Understandably, the condition detrimentally affects a patient's quality of life; thus, treatment measures have also been outlined. This study aims to provide updated literature on Moebius Syndrome MBS and improve understanding of the condition.

Influence of different ligation methods on force and moment generation in a simulated condition of the maxillary crowded anterior dentition with linguo-version and rotation.

Most orthodontic cases consist of varying degrees of crowding. To manage crowded dentitions, nickel-titanium archwires with various ligation methods are often used. We aimed to investigate the effect of different ligation methods with respect to force and moment and suggest the efficient ligation method for treating rotation and displacement simultaneously. We built a model that simulated the three anterior teeth of the maxilla. The teeth on the two ends were fixed, and the middle tooth was set in several different positions by manipulating the amount of displacement in bucco-lingual direction and rotation angle. The measurements were taken with three different ligation methods of self-ligation (SL), elastomeric o-ring ligation on both side wings (EB), and on one side wings (EO). The magnitude of linguo-buccal force exceeded the standard optimal force in each condition examined and was significantly larger in EB than in other ligation methods. Moreover, the magnitude of moment generation with SL was suitable in the 0.0mm linguo-version, whereas it was suitable with EO in the linguo-version ranging 1.0-3.0mm. The ligation method significantly affected the force and moment. SL and EO are recommended in dentitions with light and deep lingual displacements, respectively.

Reconsideration of Leeway Space Calculated Using Models from Same Patients at Different Growth Stages.

In this study, original leeway space was determined using plaster models prepared from the same individuals over successive years and compared with that reported in an earlier study. The plaster models used for measurement were prepared from a normal dentition group comprising 64 patients and a crowded dentition group comprising 29. The mesiodistal crown width of the deciduous canines, deciduous first molars, and deciduous second molars, as well as that of the canines, first premolars, and second premolars was measured. Leeway space was then calculated and the results compared with that previously reported. The average maxillary and mandibular leeway spaces calculated in the same individuals were 1.46 and 2.66 mm, respectively, whereas those calculated from data collected from different individuals were 0.89 and 2.83 mm, respectively. No direct statistical comparison of leeway space between this and the earlier report was possible. The present results did indicate, however, that it was larger in the maxilla than previously reported. A larger leeway space is advantageous for the normal arrangement of the permanent teeth. While the mesiodistal crown width of some of the lateral segment teeth in the present study was significantly larger in boys than in girls, no significant difference was observed in leeway space between sexes. The mesiodistal width was larger in multiple permanent teeth such as canines in the crowded dentition group, and this difference was significant in boys. On the other hand, no difference was observed in mesiodistal width in the deciduous teeth between the two groups. These results showed a tendency toward larger teeth and less leeway space in the permanent dentition in the crowded dentition group, which may have been a factor in why such crowding occurred.

Unilateral Premolar Crossbite and Atypical Extraction Case Treated with Clear Aligner

A unilateral buccal crossbites can be observed in adult patients with skeletal asymmetry and crowded dentition. This case report describes the orthodontic treatment with clear aligners for a 57-year-old female with chin deviation, lower dentition crowding and a unilateral complete buccal crossbite in right premolars. Mandibular single incisor extraction was planned to relieve crowding and the crossbite was resolved by intrusion of upper premolar and uprighting of lower premolar with clear aligners in combined with inter-arch elastic. The entire treatment was completed within 20 months and the treatment result showed good vertical control. This case report demonstrates that clear aligners can be considered as an effective, esthetic, and comfortable tool for premolar crossbite correction, when the treatment sequence on ClinCheck® was designed properly. Also, one incisor extraction was a good option in specific case, especially when anterior Bolton discrepancy are larger than normal.

Non-extraction protocol for correction of crowded dentition in a patient with horizontal growth pattern” – (A case report)

Non-extraction protocol for correction of crowded dentition in a patient with horizontal growth pattern” – (A case report)

Evaluation of Dental Crowding and Spacing in Relation to Tooth Size and Arch Dimensions in a Sample of Sudanese Adults

This study aimed to compare tooth size and arch dimensions between normal, crowded, and spaced groups in a Sudanese sample. A sample of 312 university students, were selected and divided into normal, crowded, and spaced groups. Each group included 104 students with equal males to females ratios. Age was ranged from 16 to 26 years. Mesiodistal (MD) tooth width of all teeth (except molars), arch perimeters, and dimension at the level of intercanine, interpremolar, and intermolar were measured for each group. ANOVA and student t-test were performed for the comparison between groups. The MD dimensions of all teeth are greater in crowded arches as compared to the teeth in normal dental arches, except for the width of the maxillary, left second premolar in females, and mandibular left second premolar in male. Spaced arches were presented with significantly smaller MD width in all teeth when compared to normal arches, except for the width of maxillary right second premolar, maxillary left first premolar, mandibular right and left second premolars in female, and maxillary right second premolar in male. Crowded arches exhibit the largest total tooth material followed by normal and spaced dentition. Spaced arches show the widest arch dimension and perimeters followed by normal and crowded dentitions. Both tooth size and arch dimensions contribute to dental crowding and spacing. Since the size of the teeth and dental arches affect the space availability of the dentition. These factors should be considered in the initial stages of orthodontic treatment planning to avoid compromised treatment outcomes.

A Accelerating tooth movement with modified surgical and dentoalveolar distraction technique- a case report

The duration of treatment is the most concern among orthodontic patients. It is of a challenge for an orthodontist to shorten the treatment time. A new surgical technique was introduced to accelerate tooth movement during orthodontic treatment. This new technique is the surgical reduction of bone mass in the pathway of desired tooth movement before orthodontic treatment. This case report explained the treatment of a 21-year-old male patient with severe-to-moderate crowded dentition and he requested to get the treatment done in a short period of time. Upper right first premolar and lower left second premolar were extracted, the bone in the desired pathway of all teeth movement was reduced and the dentoalveolar distraction procedure performed using nickel-titanium closing coil spring and rubber power chain. Full teeth alignment was achieved in 3 months period and the anchorage teeth were able to withstand the retraction forces with minimal anchorage loss.

Relationship of crowded teeth and Oral Hygiene among urban population in Medan

Crowded teeth could present a challenge in maintaining oral hygiene through brushing, as it is difficult to remove food debris in the interdental area, causing plaque accumulation and calculus formation, which leads to caries and gingivitis, or even destruction of the supporting tissue, which leads to tooth mobility. This study aims to determine the relationship of crowded teeth and oral hygiene among the urban population in Medan. This research is an analytic study with a cross-sectional design. The samples of this research consists of 100 adolescents in Medan. Based on the examination result of 100 subjects, 50 subjects with normal tooth arrangement, and 50 subjects with crowded teeth. This information was determined by examination of the dental condition and Oral Hygiene Index Simplified (OHI-S) measurement. The examination was performed by placing the explorer on 1/3 incisal or occlusal area and gently moving it to the 1/3 gingival or cervical area on a specific tooth. The results of the study were tested with the Chi-square test. The result shows that subjects with normal tooth arrangement present average OHI-S score of 0.66 which is categorized as good oral hygiene. Subjects with a crowded dentition exhibit an average OHI-S score of 1.33 which was categorized as moderate oral hygiene. The findings of this research reveal that there is a significant correlation between of crowded teeth and oral hygiene among adolescents in Medan. Abnormal tooth arrangement influences the condition of oral hygiene among adolescents.

Tooth width Ratio in Crowding and Noncrowding dentition among patient Attending BSMMU

Crowding is a common presentation among thepatients seeking orthodontic treatment. The cause of crowding could be various such as mesiodistal tooth width discrepancy, boney discrepancy among the jaw, earlyloss of deciduous molar, different patterns of malocclusion, ethnic group, nutritional and developmental factor.Materials and Methods: One hundred cases were selected among which 31 were male and 69 were female, 70 cases had crowded dentition and 30 cases had non crowded dentition. Bolton’s Overall ratio and Anterior ratio were calculated for every case and comparison was done among crowded and non crowded dentitions.Result: Mean Overall ratio and mean anterior ratio were found to be 91.06% and 79.66% Neither Overall ratio nor Anterior ratio was significant for crowding and non crowding cases. On comparing for male and female, only anterior ratio was found to be significant in female in crowding and non crowding cases. Ban J Orthod &amp; Dentofac Orthop, April 2014; Vol-4 (1-2), P.12-15

An Evaluation of Dental Crowding in Relation to the Mesiodistal Crown Widths and Arch Dimensions in Southern Indian Population.

With the advancement in imaging technology, 3D dental computed tomography plays a very significant role in orthodontic treatment and diagnosis. To evaluate dental crowding in relation to the mesiodistal crown widths and arch dimensions and also to determine the differences of dental crowding among males and females, in Southern Indian population. A total of 132 subjects were divided into two groups: crowded and non-crowded, each comprising 66 subjects (33 males and 33 females), aged between 15 and 35 years, who were referred for computed tomography scan of brain to the radiology department, were selected. During the scan both the jaws were included in the image. The 2D images were converted to 3D images using volume rendering software. By using measurement tool, individual and collective mesiodistal crown widths of canine, first and second premolar and first molar and arch perimeter of both the maxillary and mandibular jaws were measured. When both the gender were considered, the mesiodistal crown widths and arch perimeter were statistically significant for dental crowding in both mandibular jaw (p-value=0.001 for both mesiodistal crown width and arch perimeter) and maxillary jaw (p-value=0.016 for mesiodistal crown width and 0.002 for arch perimeter). However, when analysed separately, in males the mesiodistal crown widths and arch perimeter were statistically significant for dental crowding in both mandibular jaw (p-value=0.001 for mesiodistal crown width and 0.002 for arch perimeter) and maxillary jaw (p-value=0.002 for mesiodistal crown width and 0.001 for arch perimeter) but in females it was not statistically significant in any jaw (p-value=0.7 for mesiodistal crown width and 0.06 for arch perimeter in mandibular jaw and p-value=0.2 for mesiodistal crown width and 0.9 for arch perimeter for maxillary jaw). The crowded group had larger tooth size and smaller arch perimeter. This study concluded that in males, both the factors i.e., mesiodistal crown width and arch dimensions contributed to dental crowding and the crowded dentition had larger mesiodistal tooth size and smaller arch dimensions; whereas, in females both the factors were not responsible for crowding in Southern Indian population.

In vitro Macro-qualitative Comparison of Three Enamel Stripping Procedures: What is the Best Shape We can get?

AimInterdental stripping is a common clinical procedure in orthodontic therapy, by reshaping the proximal contacts. Handheld abrasive strips have been criticized as time-consuming process. Metallic strip system, diamond disk, or segment disks have become increasingly popular. The aim of this study is to evaluate the morphological aspects of remodeled dental surfaces so as to conclude which of the different techniques (disk, bur, or strip) used to reduce the mesiodistal diameter is the best to reproduce the initial contour of the proximal surface of the tooth.Materials and methodsSeventy-nine pieces (“teeth”) were prepared from permanent healthy teeth (premolars and molars) extracted for orthodontic reasons. They were mounted on a stand resembling the position of the natural teeth in a mild crowded dentition. The “teeth” are divided into three groups as follows: group S (strip): 26 “teeth,” group D (disk): 25 “teeth,” group B (bur): 28 “teeth.” In order to study the changes, these prepared “teeth” are macro-photographed in groups of 5 before and after proximal grinding.ResultsThe “teeth” contours have been identified using piecewise cubic Hermit polynomials. The change in the contour has been traduced in terms of the change of curvature in the “teeth” contours. We used the z-test in order to find the confidence interval for the proportion of the class “+” for each of the techniques B, S, and D. With confidence level of 95%, we obtained the following confidence intervals:B = (0.6943; 0.9057); S = (0.9093; 1.0138); D = (0.6184; 0.8616)These results can be interpreted, as the technique S is significantly much better than the other two techniques if we aim at conserving the shape of the teeth before and after treatment.ConclusionWe conclude that the use of a strip for remodeling the proximal surface of a tooth is an optimal technique to preserve the proximal shape of the tooth although it requires more time.Clinical significanceThe use of abrasive strip preserves the best shape of the proximal side. Abrasive strip could be the last step of any proximal reshaping technique.How to cite this article: Nassif N, Gholmieh MN, Sfeir E, Mourad A. In vitro Macro-qualitative Comparison of Three Enamel Stripping Procedures: What is the Best Shape We can get? Int J Clin Pediatr Dent 2017;10(4):358-362

Changes in mandibular incisor position and arch form resulting from Invisalign correction of the crowded dentition treated nonextraction.

To investigate changes in mandibular incisor position resulting from Invisalign correction of the crowded dentition without extraction. A retrospective chart review was completed on 61 adult White patients. Patients were categorized into three groups based on the value of pretreatment crowding of the lower dentition: 20 mild (2.0-3.9 mm), 22 moderate (4.0-5.9 mm), and 19 severe (>6.0 mm). Cephalometric radiographs were measured to determine lower incisor changes. Interproximal reduction and changes in arch width were also measured. Statistical evaluation of T0 and T1 values using paired t-tests and analysis of covariance were applied to evaluate mean value changes. Lower incisor position and angulation changes were statistically significant in the severe crowding group. There were no statistically significant differences in lower incisor position between the mild and moderate crowding groups. There was a statistically significant increase in buccal expansion in each of the three groups. Invisalign(®) treatment can successfully resolve mandibular arch crowding using a combination of buccal arch expansion, interproximal reduction, and lower incisor proclination. When there is <6 mm of crowding, lower incisor position remained relatively stable. The lower incisors proclined and protruded in the more severely crowded dentitions (>6 mm).

Mesio-distal crown dimension of permanent dentition in normal, crowding, and spacing of young adult sample aged 18-25 years

This study aimed to assess the effect of tooth width in malocclusion in relation to normal, crowding, and spacing dentition. Materials and methods: The sample included dental casts of some dental students and orthodontic patients; their age was (18-25) years and having three groups normal, crowding, and spacing dentition groups. The sample was equally divided to three groups normal, crowding, and spacing dentition groups, each group contained 50 maxillary and 50 mandibular casts that were further subdivided by gender; all the stone casts were measured by highly sensitive digital vernier. Results and Conclusions: Non-significant side difference was found in both dental arches in the three studied groups. Males had higher mesiodistal crown dimension than females in all three groups, with significant gender difference in crowding and normal dentition groups. The mesiodistal distance of the segment measurements (Total Anterior material; Total Posterior material and Total teeth material) were larger in crowded dentition then followed by normal and spaced dentition groups respectively in both gender. Total Anterior material in both arches had direct significant correlation with crowding malocclusion, while maxillary Total Anterior material had indirect significant correlation with spacing malocclusion.

Orthodontic Treatment of Severe Crowding Malocclusion with Extraction of premolars.

Space deficiency in a crowded dentition is a main indication for premolar extraction therapy. Class I malocclusions with severe crowding in non growing patients can be treated by upper lower first premolar extraction using an edgewise technique with multi loop edgewise arch wire (MEAW). The following case report describes a patient with severe tooth crowding, where the result of the treatment was acceptable and relatively stable. It was concluded that the elimination of tooth tissue discrepancy by the extraction of first premolars provides a good means in the treatment of crowding malocclusions. DOI: http://dx.doi.org/10.3329/bjodfo.v2i2.16161 Ban J Orthod &amp; Dentofac Orthop, April 2012; Vol-2, No.2, 30-33

Longitudinal observation of the changes of the consecutive curve of the incisal edge, tip and cusp tip from deciduous and permanent dentition — Comparison between normal and crowded dental arch —

We observed changes in the consecutive curve of the incisal edge, tip and cusp tip using serial dental casts from the deciduous to permanent dentition period in the same 44 individuals showing normal dentition at the time of the completion of deciduous dentition. In addition, in both the maxilla and mandible, the curvature gradually increased from the deciduous to permanent dentition period. Changes in the superoinferior position of each measurement site were similar between the normal and crowded dentition groups; however, at 4 measurement sites, the amount of change from the completion of deciduous dentition to immediately before the transition to mixed dentition significantly differed between the two groups ( P < 0.01); therefore, using values at the 4 measurement sites, discriminant analysis was performed. When the amount of change at the 4 measurement sites showing significant differences was indicated by variables X 1 –X 4 , the discriminant function was: Z = 0.1233+1.2588X 1 –0.9483X 2 +0.0612X 3 –0.7749X 4 . Normal dentition (Z > 0) could be discriminated from crowded dentition (Z < 0) with a probability of 77.3%. These results suggest that this amount of change is a factor facilitating discrimination between normal and crowded dentition.