Skeletal and Dental Morphological Characteristics of the Maxillary in Patients with Impacted Canines Using Cone Beam Computed Tomography: A Retrospective Clinical Study

The aim of this study is to analyze the skeletal and dentoalveolar morphological characteristics of the maxillary in subjects with a unilateral palatally impacted canine using Cone Beam Computed Tomography (CBCT). A retrospective clinical study was conducted of 100 adult patients divided into two groups: one consisting of patients with a unilaterally palatally impacted maxillary canine (GI), with the subgroups in the right and left hemiarches (GI-R and GI-L), and the second, without impacted canine, as the control group (CG). The CBCT measured skeletal variables (maxillary basal width and alveolar crest height) and dentoalveolar variables (inclination of the upper incisor, tooth lengths of incisors and canines, arch length, tooth size and bone dental discrepancy). In skeletal variables, statistically significant differences were found in alveolar crest height (ACH) in all groups and subgroups (p < 0.01). In the dentoalveolar variables, there were differences in the angle of the upper incisor (II) and lateral incisor length (LLIL) between the GI and GC and the angle of the upper incisor (II′), arch length (AL′) and arch length-tooth size discrepancy (ATD′) among the GI subgroups (p < 0.01). There are skeletal and dentoalveolar differences in patients with unilateral palatally impacted maxillary canines, with lower angular and linear measurements compared with patients without impaction.

Mesiodistal dimensions of teeth in Serbian orthodontic patients with hypodontia

Introduction/Objective. Hypodontia is a common dental anomaly that occurs either in a non-syndromic form or as a part of various syndromes. It is considered a multifactorial condition with genetic, epigenetic and environmental influences, the interplay of which can lead to various anomalies in tooth size and number. The aim of this study was to assess mesiodistal tooth dimensions in Serbian hypodontia orthodontic patients and compare them to healthy controls using digital study models. Methods. Fifty subjects (30 females, 20 males) divided into two groups - 25 with hypodontia (15 females, 10 males) and 25 gender-matched controls (15 females, 10 males) were included in the study. Alginate impressions were taken and plaster models poured, digitized and imported into the software where mesiodistal dimensions were obtained. Results. Intra-operator reliability was high. All teeth in the hypodontia group had smaller mesiodistal dimensions compared to controls. Statistical significance was noted for all teeth except for upper canines. No statistically significant differences were found between males and females in neither the hypodontia nor the control group, except for lower canines, which were significantly smaller in both hypodontia and control females. The most commonly missing teeth were upper lateral incisors, and lower and upper premolars. Conclusion. Hypodontia group presented with smaller mesiodistal dimensions compared to controls. The greatest difference in mesiodistal dimensions was found in upper lateral incisors and lower first molars. Lower canines were significantly larger in males compared to females in both groups.

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.

A Rare Tooth Anomaly (Double Teeth) in Deciduous Teeth: A Case Report

Introduction: The Size and shape of the teeth are genetic characteristics. Anomaly in tooth size and shape is due to disturbances in a sequence of morph differentiation and his to differentiation in tooth bud formation periods and is more common in permanent dentition than deciduous teeth. The most common tooth size discrepancy is in the upper lateral incisor and upper and lowers 2nd premolar teeth. About 5% of malocclusions are due to tooth size discrepancy. For having the best occlusion, we must have the appropriate size and shape of teeth. As there is a relation between deciduous and permanent teeth, proper evaluation and timely intervention are essential for achieving a good occlusion in anterior and posterior segments of permanent teeth. Thus we need interceptive orthodontic in mixed dentition period with a good treatment plan for removing the malformed tooth at the proper time and appliance therapy for eruption guidance of other teeth. Case Report: A rare tooth anomaly (double teeth) in deciduous teeth: The case reported here is a 9- years old boy with a delayed eruption of the right lower permanent lateral incisor and gemination of lower right deciduous canine and crowded upper incisors that refer to the orthodontic department of dental school of Ahvaz Jundishapur University of Medical Sciences on7th October of 2020. Conclusion: After creating patient’s file, the further steps of molding from the patient and gathering all diagnostic records such as panoramic radiography, intraoral photography was carried out and ordered to remove the malformed baby tooth afterward. In the next stage, on the patient’s treatment, we installed a strap onto the patient’s first permanent molars, remolded them, then created a lingual arch to maintain the vegetative space in the lower permanent canine and prevent its collapse, and increased the patient’s overbite.

LATERAL PEG-SHAPED INCISIVE AESTHETIC TREATMENT WITH INDIRECT VENEER RESTORATION USING CERAMO POLYMER RESTORATION

Peg shape is one of the abnormalities of dental anatomy, i.e. tooth size is smaller than average and tapered shape. These peg-shaped teeth are often found in the maxillary lateral incisors and third molars. The form on the lateral incisor often causes aesthetic problems because of its anterior position. One of the treatments for peg-shaped teeth is Veneer. Case report: 26 years old woman had a peg-shaped shape on both lateral incisors. Indirect veneer aesthetic treatment was performed using Ceramage to correct the form and cover the diastema to achieve better aesthetics. Wax-up is done to see the suitability of the shape and proportion of the Veneer. Patients get a visual picture of the expected treatment results. The treatment results in Ceramage gave an excellent condition in improving the shape of the Peg-shaped incisor. The veneer colour resembles natural teeth, and the patient is satisfied with the treatment results. Ceramage can be used as a treatment option for anterior teeth with deformities. Ceramage Veneer is an alternative that can be done to improve the aesthetic appearance at a more economical cost for anterior teeth.

Modified Intra-alveolar appliance — Case report

Arch space/ Tooth size discrepancy occurs whenever there is a early loss of the deciduous molars which eventually leads to malocclusion. Prevention of this discrepancy has always been a challenge for a pediatric dentist. This case report describes modified bilateral distal shoe appliance fabricated due to inadequate abutment support.

Central incisors shape and proportions prevalence in Argentinian university students: by visual assessment and a new standardized method

The aim of this study was to analyze the dimensions of the clinical crown of upper central incisors and the prevalence of tooth shapes by two different protocols. Assessment was performed on each of the 111 dental stone type V maxillae models of students of dentistry from Buenos Aires University [93 females and 18 males, mean age 23.70 (± 2.26) years] The mesial and distal-vestibular angles were defined on each right upper incisor, and the following segments were defined: AB (zenith - incisal edge), CD, EF, GH (apical, middle, and incisal thirds - vestibule - mesial and vestibule-distal angles) and their lengths were determined with a precision caliper. Then, the CD/AB, EF/AB and mean CD-EF/AB ratios were calculated. Shapes were assessed by four independent observers, three of whom evaluated digital images of the models, while the fourth had no access to the images, and determined the shapes using an algorithm developed from the dimensions of the studied segments. Rates and confidence intervals were determined, and Fleiss’ Kappa was calculated to assess the agreement among the evaluators who worked with the images and among all of them. Average incisor length was 10 mm, and widths at CD and EF were 7.35 mm (0.65) and 8.27 mm (0.58), respectively. Regarding shapes, 51.58% (47.90-55.20) of the incisors were identified as square, 18.02% (14.50-21.90) as ovoid and 30.41% (30.00-30.90) as triangular. Fleiss’ Kappa agreement was 0.71 (0.62-0.80). The application of the proposed algorithm provided a considerable level of agreement among the observers. Regarding tooth size, both the average segment length and the proportions were similar to those reported by various authors.

An ancient dental signalling centre supports homology of an enamel knot in sharks

Development of tooth cusps is regulated by the enamel knot signalling centre. Fgf signalling regulates differential proliferation between the enamel knot and adjacent dental epithelia during tooth development, leading to formation of the dental cusp. The presence of an enamel knot in non-mammalian vertebrates is debated given differences in signalling. Here we show the conservation and restriction of fgf10 and fgf3 to the sites of future dental cusps in the shark (Scyliorhinus canicula), whilst also highlighting striking differences between the shark and mouse. We reveal shifts in tooth size, shape and cusp number following small molecule perturbations of canonical Wnt signalling. Resulting tooth phenotypes mirror observed effects in mammals, where canonical Wnt has been implicated as an upstream regulator of enamel knot signalling. In silico modelling of shark dental morphogenesis demonstrates how subtle changes in activatory and inhibitory signals can alter tooth shape, resembling phenotypes observed following experimental Wnt perturbation. Our results support the functional conservation of an enamel knot-like signalling centre throughout vertebrates and suggest that varied tooth types from sharks to mammals follow a similar developmental bauplan. Lineage-specific differences in signalling are not sufficient in refuting homology of this signalling centre, which is likely older than teeth themselves.

Bolton tooth size discrepancy among different malocclusion groups in two different ethnic groups of Nepalese population

Introduction: The tooth size ratios may vary among different ethnic groups and different malocclusion groups. The objective of this study is to see the tooth size discrepancies in two major ethnic groups of Nepal; Indo-Aryans and Tibeto-Burmans and different malocclusion groups and compare it with the Bolton’s study. Materials and Method: The anterior and overall ratios were compared between Indo-Aryans and Tibeto-Burmans according to different malocclusion groups with Bolton’s study with one sample t-test. The differences in ratios in ethnic groups and gender were seen with one sample t-test. The differences in mesio-distal tooth width amongst the two ethnic groups were seen. One sample ANOVA was used to see any correlation between the ethnic groups and the different malocclusion groups. Result: The anterior ratio and overall ratio in Indo- Aryans and Tibeto-Burmans in all the malocclusion groups were greater than the Bolton’s study but was not statistically significant. There was significant differences in anterior ratio between Indo-Aryans (77.63 + 2.74%) and Tibeto-Burmans (78.51 + 2.76%), p value= 0.024. There were no statistical significant differences in the anterior and overall ratio amongst males and females. The mesio-distal tooth size was greater in Tibeto-Burmans as compared to Indo-Aryans expect for maxillary right and left central incisors. Conclusion: The Tibeto-Burmans had higher anterior ratio as compared to Indo-Aryans. The Tibeto-Burmans had broader teeth as compared to Indo-Aryans except for maxillary central incisors.