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The Bulletin of Tokyo Dental College Jan 2023In 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...
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.
Topics: Humans; Odontometry; Molar; Tooth Crown; Bicuspid; Malocclusion
PubMed: 36384757
DOI: 10.2209/tdcpublication.2021-0046 -
PloS One 2024Morphological variation in modern human dentition is still an open field of study. The understanding of dental shape and metrics is relevant for the advancement of human...
Morphological variation in modern human dentition is still an open field of study. The understanding of dental shape and metrics is relevant for the advancement of human biology and evolution and is thus of interest in the fields of dental anthropology, as well as human anatomy and medicine. Of concern is also the variation of the inner aspects of the crown which can be investigated using the tools and methods of virtual anthropology. In this study, we explored inter- and intra-population morphometric variation of modern humans' upper third and fourth premolars (P3s and P4s, respectively) considering both the inner and outer aspects of the crown, and discrete traits. We worked by means of geometric morphometrics on 3D image data from a geographically balanced sample of human populations from five continents, to analyse the shape of the dentinal crown, and the crown outline in 78 P3s and 76 P4s from 85 individuals. For the study of dental traits, we referred to the Arizona State University Dental Anthropology System integrated with more recent classification systems. The 3D shape variation of upper premolar crowns varied between short and mesio-distally broad, and tall and mesio-distally narrow. The observed shape variation was independent from the geographical origin of the populations, and resulted in extensive overlap. We noted a high pairwise correlation (r1 = 0.83) between upper P3s and P4s. We did not find any significant geographic differences in the analysed non-metric traits. Our outcomes thus suggest that geographical provenance does not play a determinant role in the shaping of the dental crown, whose genesis is under strict genetic control.
Topics: Animals; Humans; Bicuspid; Anthropology, Physical; Hominidae; Anthropology; Tooth Crown
PubMed: 38593117
DOI: 10.1371/journal.pone.0301482 -
Clinical and Experimental Dental... Dec 2021The shapes of gubernaculum tracts (GTs) in molars as accessional teeth remain unidentified. To elucidate imaging peculiarities of GTs in molars with aging on...
OBJECTIVES
The shapes of gubernaculum tracts (GTs) in molars as accessional teeth remain unidentified. To elucidate imaging peculiarities of GTs in molars with aging on multidetector-row computed tomography (MDCT).
MATERIAL AND METHODS
This retrospective study was conducted using CT images, including maxillary and mandibular molars, with no abnormal findings from 239 patients. Shapes of alveolar bone, GTs, and dental sacs of the maxillary and mandibular molars were analyzed multi-sectionally. Correlations between 2- and 3-dimensional imaging figures of GTs in molars and chronological age or stage of molar formation were analyzed.
RESULTS
Some forms of GTs in maxillary and mandibular third molars were observed. In the early stage, GTs were visualized as bone defect lines on the dentition and grooves on the mesial alveolar crest continuous with the dental sac to mesial tooth bud. GTs of the third molar formed a J-shape in maxillary teeth and Y-shape in mandibular teeth in the middle stage, as alveolar bone around the GT developed. In the mature stage, the course of the GT changed to straight and perpendicular. Some GT forms were also identified in first and second molars. Significant correlations were found between GT alterations and chronological age or stage of molar formation. Moreover, tracts continuing from the distal side of mandibular third molars were detected.
CONCLUSIONS
This paper describes the peculiarities and process of progression for GTs in molars, and the existence of tracts continuing from the distal side of mandibular third molars, unlikely dentition with deciduous predecessors. These preliminary data should prove beneficial for studies focusing on GTs in molars.
Topics: Gubernaculum; Humans; Molar; Molar, Third; Retrospective Studies; Tomography, X-Ray Computed
PubMed: 34137209
DOI: 10.1002/cre2.452 -
Canadian Journal of Dental Hygiene :... Jun 2023Lobodontia is a rarely documented dental condition associated with pointed or conical cusps on premolars and canines, multitubercular occlusal surfaces on molar teeth,...
Lobodontia is a rarely documented dental condition associated with pointed or conical cusps on premolars and canines, multitubercular occlusal surfaces on molar teeth, and irregularly shaped incisors. Information on this uncommon condition continues to be scarce, with particularly little information available on the primary dentition. The purpose of this article is to describe 6 cases of lobodontia and discuss the variability in presentation and management. Previously unreported manifestations in the primary dentition are included. The cases described in the current study demonstrate the spectrum of clinical and radiographic features of the condition, and show that a varied, individualized approach to treatment is necessary.
Topics: Humans; Dentition, Permanent; Tooth Abnormalities; Molar; Bicuspid
PubMed: 37464991
DOI: No ID Found -
Medicina (Kaunas, Lithuania) Mar 2024The gradual movement of a tooth away from the occlusal plane is called infraocclusion or reinclusion. Reincluded teeth are most often deciduous molars, and permanent... (Review)
Review
The gradual movement of a tooth away from the occlusal plane is called infraocclusion or reinclusion. Reincluded teeth are most often deciduous molars, and permanent teeth are less frequently affected. Depending on the level of the infraocclusion, the severity of the disorder is classified as mild, moderate, or severe. The etiology of the phenomenon is not fully known. Tooth submerging can lead to serious complications, such as abnormal position of adjacent teeth, displacement of the bud of the permanent successor, shortening of the dental arch, or developmental disturbances of alveolar process. Early diagnosis of the tooth infraocclusion and regular monitoring of its progression help to avoid serious permanent sequelae. The treatment of reinclusion often involves only observation. However, in some cases, the therapeutic procedure requires interdisciplinary treatment by specialists from various fields of dentistry. This study presents current methods of diagnosis and treatment of patients with submerged teeth.
Topics: Humans; Dentition, Permanent; Tooth, Deciduous; Malocclusion; Tooth Extraction; Mandible; Tooth Eruption
PubMed: 38541149
DOI: 10.3390/medicina60030423 -
Journal of Dentistry Jun 2022The aim of this RCT was to compare the caries preventive efficacy and the slowing down of previous caries lesions of toothpastes containing fluoride biomimetic... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
The aim of this RCT was to compare the caries preventive efficacy and the slowing down of previous caries lesions of toothpastes containing fluoride biomimetic hydroxyapatite (HA) complex compared to sodium monofluorophosphate fluoridated toothpastes in Italian schoolchildren. To validate this hypothesis a triple-blind randomized clinical trial was designed.
METHODS
In total 610 children (4-5 and 6-7 years) were enrolled. Four toothpastes, two containing fluoride-substituted hydroxyapatite (HAF) (1000 and 1450 ppmF) and magnesium-, strontium-, carbonate-substituted hydroxyapatite, in a chitosan matrix and two Mono fluoridated toothpastes (1000 and 1450 ppmF) were randomly administered during 24 months to two groups with younger children (G) and to two groups with older children (G), those containing 1450 ppmF. ICDAS was used to score lesions as initial (up to score 2), moderate (scores 3-4) and severe (scores 5-6). The children were instructed to brush for two minutes three times/day. Caries examination was repeated at 12 and 24 months. The efficacy of the treatment was assessed by calculating the reduction in Risk Ratio (RR) and the number needed to treat (NNT). Results; Overall, 518 patients (G = 268; G = 250) concluded the trial. The drop-rate was 11.84% for G and 17.22% for G. The caries increment at 24-month evaluation was statistically lower in the primary dentition in the HAF arms compared to the traditional fluoridated arms (0.18 vs 0.27 p = 0.04 in G and 0.16 vs 0.30 p = 0.01 in G for severe lesions). In the permanent dentition (G), caries increase was also statistically lower in the HAF arm, both for initial and severe lesions (0.09 vs 0.17 p = 0.02 and 0.18 vs 0.28 p = 0.01, respectively). In primary dentition, children receiving HAF Toothpaste had a RR of 39% (G) and 38% (G), compared to children receiving traditional Toothpastes. The RR in the permanent dentition was 29% in children treated with HAF toothpaste. Conclusions; The use of toothpastes containing biomimetic hydroxyapatite and fluoride reduces caries increment in children over a period of 2 years more than traditional fluoridated toothpastes.
Topics: Adolescent; Cariostatic Agents; Child; Dental Caries; Dentition, Permanent; Durapatite; Fluorides; Humans; Toothpastes
PubMed: 35139410
DOI: 10.1016/j.jdent.2022.104049 -
British Dental Journal Mar 2023In the next part of this series on tooth wear management, we discuss the indications and clinical stages for the provision of removable prostheses for the treatment of...
In the next part of this series on tooth wear management, we discuss the indications and clinical stages for the provision of removable prostheses for the treatment of severely worn and depleted dentitions. The general design features of a complex prosthesis are described for reorganised occlusal schemes and maintenance guidelines are explained. In addition, the clinical stages for three different situations are described: removable-only approaches, and combined fixed and removable in the same arch and separate arches. The value of providing removable prostheses in worn dentitions allows the immediate rehabilitation of severely worn teeth taking a non-invasive and retrievable approach when the remaining dentition is of poor quality or structure and/or there are missing teeth.
Topics: Humans; Dentition; Prosthodontics; Dental Implants; Tooth Wear; Tooth Attrition; Denture, Partial, Removable
PubMed: 36964363
DOI: 10.1038/s41415-023-5583-5 -
Journal of Orofacial Orthopedics =... Oct 2022To assess the validity, reliability, reproducibility, and objectivity of measurements on stone casts of patients with mixed dentitions compared to measurements on...
PURPOSE
To 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.
METHODS
Pairs 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.
RESULTS
Significant (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.
CONCLUSION
Measurements 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.
Topics: Dentition, Mixed; Humans; Imaging, Three-Dimensional; Models, Dental; Reproducibility of Results; Software
PubMed: 35238945
DOI: 10.1007/s00056-022-00376-9 -
La Tunisie Medicale Dec 2023The constant increase of both esthetic demands and advancement in materials and technologies have led to the development of guidelines to achieve optimal aesthetic... (Observational Study)
Observational Study
INTRODUCTION
The constant increase of both esthetic demands and advancement in materials and technologies have led to the development of guidelines to achieve optimal aesthetic results. These tools are useful to predict the teeth proportion and dimensions. Golden and Red proportion are the most described theories.
AIM
of present study was to evaluate the existence of both Golden and Red proportion in the maxillary anterior teeth among a North-African population.
METHODS
This was an observational study performed at the Fixed Prosthetic department of the dental clinic of Monastir, Tunisia. The study included participants with full intact anterior dentition. Those with diastema or teeth crowding were excluded. For each one, an alginate impression was done. Measures were, including the perceived width and length, have been taken on casts using digital caliper. Width ratios of maxillary lateral incisor to maxillary central incisor and lateral incisor to canine were calculated.
RESULTS
The study included 100 Tunisian participants including 97 females and 21 males. The maxillary central incisors were the largest (8.60±0.58mm) and the longest (99.71±1.14mm). The ratio was 0.89±0.09mm. Anterior teeth dimensions were not statistically not different between males and females. Significant differences were observed between calculated ratios with GP and to each other's. (p=0).
CONCLUSIONS
Either GP nor RP is applicable amongst the Tunisian Population.
Topics: Male; Female; Humans; Maxilla; Cuspid; Esthetics, Dental; Odontometry; Incisor
PubMed: 38477197
DOI: No ID Found -
International Journal of Environmental... Feb 2021Edentulism and terminal dentition are still considered significant problems in the dental field, posing a great challenge for surgical and restorative solutions... (Review)
Review
Edentulism and terminal dentition are still considered significant problems in the dental field, posing a great challenge for surgical and restorative solutions especially with immediate loading protocols. When the implant placement is planned immediately after extraction with irregular bone topography or there is an un-leveled alveolar ridge topography for any other reason, bone reduction may be required to level the alveolar crest in order to create the desired bone architecture allowing for sufficient bone width for implant placement and to insure adequate inter-arch restorative space. Bone reduction protocols exist in analog and digitally planned methodologies, with or without surgical guides to achieve the desired bone level based upon the desired position of the implants with regard to the restorative outcome. The objective of this paper was to scrutinize the literature regarding the practice of bone reduction in conjunction with implant placement, and to review different types of bone reduction surgical guides. Results: The literature reveals different protocols that provide for bone reduction with a variety of bone reduction methods. The digitally-planned surgical guide based on Cone-Beam computerized tomography (CBCT) scan reconstructed data can improve accuracy, reduce surgical time, and deliver the desired bone level for the implant placement with fewer surgical and restorative complications. The clinician's choice is based on personal experience, training, and comfort with a specific guide type. Conclusions: Bone reduction, when required, is an indispensable step in the surgical procedure to attain suitable width of bone in anticipation of implant placement ideally determined by the desired tooth position and required restorative space based on material selection for the chosen framework design, i.e., hybrid, monolithic zirconia. Additionally, bone reduction and implant placement can be accomplished in the same surgical procedure, minimizing trauma and the need for two separate interventions.
Topics: Alveolar Process; Cone-Beam Computed Tomography; Prostheses and Implants; Surgery, Computer-Assisted; Tooth
PubMed: 33673563
DOI: 10.3390/ijerph18052341