Unerupted Premolars Research Articles

Equation for Tooth Size Prediction from Mixed Dentition Analysis for Taiwanese Population: A Pilot Study.

Background: In mixed dentition analysis, estimation of the mesiodistal width of unerupted permanent canines and premolars is essential for successful diagnosis and treatment planning. The present study aimed to develop a simple linear equation to predict permanent tooth sizes from mixed dentition analysis for Taiwanese people. Methods: The sample comprised 200 dental casts, derived from Taiwanese patients (100 males and 100 females; age, 12–35 years). Mesial distal tooth widths were measured in dental casts with a digital caliper. A student’s t-test was conducted to detect tooth size correlations with gender-specific differences, as well as intra-arch counterparts. Standard linear regression was conducted to develop a simple equation representing predictions of canine-premolar relationships. Results: All teeth were not significantly different between the left and right sides, regardless of gender and upper or lower arches. In terms of types of teeth, males had larger tooth dimensions in both arches than females. New regression equations for estimating the dimensions of the unerupted canines and premolars in the Taiwanese population were developed. Conclusions: Using a sample of Taiwanese people, new models derived for females and males separately were developed, which should provide highly accurate predictions for unerupted canines and premolars in the Taiwanese population.

Applicability of Two Non-Radiographic Mixed Dentition Analysis Methods in Orthodontic Patients

Background: Using erupted components of a dental arch to estimate the width of the unerupted dental components are the basis of mixed dentition analysis. Non-radiographic mixed dentition analysis employs a regression equation to assess the width of the unerupted canines and premolars. In this study, we assessed the applicability of two non-radiographic methods of mixed dentition analysis in orthodontic patients. Methods: This cross-sectional research was carried out from the records of Ziauddin College of Dentistry, Department of Orthodontics, from November 2019 to March 2020. Pre-treatment dental casts of 120 subjects (60 males and 60 females) aged between 12-30 years undergoing orthodontic treatment were selected. The mesiodistal widths from the left first molar to the right first molar were measured using a digital Vernier caliper on pretreatment dental casts of both arches. Bachman’s and Tanaka-Johnston methods were applied to estimate the widths of canine and premolars. Gender dimorphism for actual and estimated values was assessed using an independent t-test and a paired t-test was applied for the comparison between the actual and estimated mesiodistal widths of canine and premolar. Results: The actual and estimated widths of canine and premolars reported 14.3±1.4 years for males and 13.4±1.2 years for females. In addition, the Bachman’s and Tanaka-Johnston method overestimated the actual widths of unerupted canine and premolar but the difference was statistically insignificant (p≥ 0.05) in both the genders. Conclusion: The two non-radiographic methods were reliable for mixed dentition analysis with minor overestimation between actual and estimated widths (ICC=0.79). This makes both the methods applicable interchangeably in regular clinical practice.

Juvenile trabecular ossifying fibroma in association with multiple mandible deciduous teeth: an atypical case report

Ossifying fibroma is a benign fibro-osseous lesion characterized by the formation of a cellular fibrous connective tissue stroma with cementum-like material and/or osseous components. The juvenile variant is reported to be an aggressive lesion in paediatric patients. Its poor symptomatology contrasts with its highly aggressive behaviour in maxillary or mandibular region. Objective: The aim of the present study is to report a case of an atypical ossifying fibroma in association of multiple deciduous teeth. Case report: A nine years-old girl was referenced to the Oral and Maxillofacial Surgery Service at Positivo University by the Paediatric Service after radiographic confirmation of a round lesion in lower left mandible region. Imaginological examination revealed a well-defined, round, with multiple radiopaque foci associated with the roots of deciduous molars and with root of first permanent mandibular molar of the left side. Lesion embedded the root and crown of the unerupted second left premolar, suggesting that the tumour arouse from it. After incisional biopsy, histopathological analysis suggested the trabecular pattern of juvenile ossifying fibroma. Surgery was conducted through an intra-oral approach. Incision was drawn in gingiva from the left lateral inferior incisor region until the unerupted second molar region, finished with a relaxing incision. A round tumour in association with the unerupted permanent premolars, which were also extracted, was removed in its entire extent by enucleation. Histopathological analysis confirmed the previous diagnosis of juvenile trabecular ossifying fibroma. Peripheral ostectomy was conducted to diminish chances of lesion relapse. Conclusion: 16 months follow-up showed no lesion recurrence.

Prediction of Combined Mesiodistal Width of Unerupted Permanent Canine and Premolars using Moyer’s Mixed Dentition Analysis in Nepalese Newar Population

Introduction: Moyer’s probability table is most commonly used to predict the mesiodistal width of permanent canines and premolars in mixed dentition. However, the table was formulated using data from Caucasian population. This study was performed to compare the Moyer’s prediction table with actual value in Nepalese Newar population as ethnicity is one of the important factor to determine teeth width.
 Materials & Method: Combined mesiodistal width of permanent canine and premolars were measured in 150 study models of Nepalese Newar orthodontic patients (75males and 75 females). The value was compared with the Moyer’s prediction table at all probability level.
 Result: There was no statistically significant difference between the actual combined width and that predicted from Moyer’s table at 85% probability level for maxilla and at 75% level for mandible in male, at 95% probability level for maxilla and at 85% probability level for mandible in female.
 Conclusion: Moyer’s probability level can be used to predict the combined mesiodistal width of permanent canines and premolars in Nepalese Newar population but at specific probability level.

Estimation of the Width of Un-Erupted canines and Premolars in Basrah Population: A cross Sectional Study

Exactprophecy of the space givesasignificantportion of an orthodontic valuation in the mixed dentition. However, the most frequently used procedures of space analysis are built on data established on Caucasian populations, so thepurpose of the present study is to appraise the applicability of the method of Moyers to estimate the mesiodistal widths of permanent canines and premolars in aassemblage of young people from south of Iraq represented by Basrah city individuals and to associate the predicted teeth widths from this formula with those gotten from Moyers’ tables and Tanaka and Johnston's equations. From a complete list of schools, 20 were randomly selected and a random sample of 207 school children was identified according to predefined selection criteria. The width of lower incisors unit, maxillary canine and premolar unit and mandibular canine premolar units were measured and used to create a regression model and a prediction equation. There was an apparent agreement between Moyers model and the present study in estimating the width of canine and premolar segments in both maxillary and mandibular arches and in both sexes. However, dimorphism in both sexes was noticed in the lower incisors widths. Moyers model of predicting canine and premolar widths was used as a comparative model for many studies worldwide. Applicability of Moyers model in Basrah seems valid from the results of this study although there is an apparent underestimation of the widths when Moyers model is applied. It is recommended to carefully use Moyers model for Basrah population.

A New Regression Equation Proposed For Mixed Dentition Analysis in Chhattisgarh, Central India Population

Objective: To develop and propose a new regression for mixed dentition analysis in Chhattisgarh, Central India population. Material and Methods: The permanent dentition dental casts of 800 (400 males and 400 females) Chhattisgarh subjects were selected. Digital caliper was used to measure the mesiodistal crown widths of teeth. The linear regression equations and correlation between four mandibular incisors and the canine-premolars segments of maxillary and mandibular arches were developed (modified Tanaka-Johnston equation) and proposed for Chhattisgarh population. Results: New standardized regression equations were formulated to predict the mesiodistal widths of unerupted canines and premolars especially for Chhattisgarh, Central India population. The equation in males for maxillary arch was Y = 11.90 + 0.39 (X) and for mandibular arch was Y = 12.23 + 0.36 (X). Similarly, the equation in females for maxillary arch was Y = 14.40 + 0.26 (X) and for mandibular arch was Y= 10.26 + 0.43 (X). A significant sexual dimorphism in teeth sizes was seen with higher mesio distal dimension in males in Chhattisgarh population. Conclusion: Sum of the mesiodistal diameter of permanent mandibular incisors can be used reliably to predict/estimate the sum of mesiodistal diameters of unerupted canines and premolars with the new regression equations.

The dentary of Wareolestes rex (Megazostrodontidae): a new specimen from Scotland and implications for morganucodontan tooth replacement

AbstractThe Middle Jurassic morganucodontan, Wareolestes rex, was previously known from only four isolated molars from Kirtlington, England. There has been debate over the position of the holotype tooth as an upper or lower molar. We describe a new Wareolestes specimen from the Kilmaluag Formation of Scotland: a partial left dentary with two erupted molars, one unerupted molar and three unerupted premolars. Empty alveoli for a canine, p1 and p3 are also present. Through detailed comparison of the morphology of the holotype and our new material, we support the original diagnosis of the holotype Wareolestes as a lower molar, most likely m1. The position of erupted and unerupted replacement teeth in the newly discovered specimen supports a diphyodont pattern of tooth replacement of premolariform dentition in Wareolestes, as suggested for other morganucodontans such as Morganucodon, Megazostrodon and Dinnetherium. However, damage to the dentary means that questions remain regarding the sequence of replacement in Wareolestes along the tooth row.

Prediction of Mesiodistal Diameter of Unerupted Second Premolars and Canines Non-radiographically

Introduction : Prediction of the mesiodistal width of unerupted permanent canines and premolars is of majorinterest for orthodontic diagnosis and treatment planning. This prediction is used to determine the tooth size-arch length discrepancy in the mixed dentition which is often made before eruption of the permanentcanines and first and second premolars. Method: The intraoral periapical radiograph of mandibular premolar region was taken. Records of 20 patients aged 13 to 14 yrs of Marathwada region with unerupted second premolar was considered. The actual measurements compared with the predicted values derived from the Tanaka and Johnston and Boston university equations. Result: Two prediction method Tanaka Johnston and Boston University show significant result for marathwada population. Conclusion: Depending on the stage of dental development, i.e., which deciduous and permanent teeth are present, the Tanaka/Johnston approach can be used when the four mandibular incisors have completely erupted, whereas the Boston University approach can be used when all the deciduous canines and first molars are still present.

Mixed dentition space analysis among Nepalese Brahmins/Chhetris

BackgroundMixed dentition space analysis forms an important part of orthodontic diagnosis and treatment planning. Regression equations are widely used for mixed dentition analysis which can vary among races. This study aimed to find out the new regression equation in estimating the size of unerupted canines and premolars for Nepalese Brahmins/Chhetris.MethodsHundred Nepalese Brahmins/Chhetris (50 males and 50 females) who met our criteria were selected among the patients attending to the Orthodontic Out-Patient Department, Institute of Medicine, Kathmandu. The mesiodistal widths of all mandibular permanent incisors; maxillary and mandibular canines and premolars were measured and analyzed. The results were also compared with predicted values from the Moyers and the Tanaka and Johnston methods. Correlation and linear regression analyses were performed between the predicted and actual tooth sizes for Nepalese Brahmins/Chhetris and standard regression equations were developed.ResultsNo significant differences were observed when the sum of canine and premolars of one quadrant is compared between sides and sex. Significant and high positive correlations were found between the mandibular incisors and the combined mesiodistal widths of the canines and premolars for the maxillary (r = 0.72) and mandibular (r = 0.73) segments. Significant differences were observed between the measured values from this study and from Moyers (50 % and 75 % probability) and Tanaka-Johnston methods.ConclusionsThe equations and charts commonly used for North American children (50th or 75th percentile) did not accurately predict for our sample, so new regression equations and tables were developed for Nepalese Brahmins/Chhetris children.

Evaluation of the frequency and demographic profile of inflammatory dentigerous cyst in Central Indian population

Objective: Inflammatory dentigerous cysts (IDCs) are the most common cysts of inflammatory origin involving immature unerupted premolars or incisors. These cysts develop as a result of intrafollicular spread of periapical inflammation from an overlying nonvital primary tooth. Recently, many case reports have been reported in the literature indicating their presence at an early age. The objective of this study was to evaluate the frequency and demographic profile of IDCs in Central Indian population. Materials and Methods: Retrospective observation of the study was made on 112 IDCs from 6625 new children reporting to the Department of Pediatric Dentistry. Following variables were recorded: Frequency, demographic profile, radiographic features, treatment, and risk factors. Descriptive analysis was made of study variables using the SPSS Version 21.0. Results: The frequency of IDC was found to be 1.7% in Central Indian population. There was male predominance with a mean age of 8.8 years. Posterior mandibular region was the most common site followed by maxillary posterior. Marsupialization was the most commonly used treatment modality. Conclusion: Oral healthcare professionals should be aware of the frequency, demographic profile, and radiographical features of IDCs so that early diagnosis and definitive treatment of these lesions can be planned.

Analyzing Mesiodistal Widths of the Permanent Teeth

Background: Prediction of the mesio-distal width of the unerupted premolars and canine is an important point to the practitioner. Objectives: The main goal of this study was to find the relationship of the teeth size to be used when needed in treatments planning. Materials and Methods: 200 plaster casts including 5600 teeth were measured and studies. A caliper with accuracy of 0.1 mm was used for measuring teeth and most teeth were measured twice and the average value was considered as the teeth size. In all cases, the vernier calipers jaws were moved along the teeth longitudinal axis and the biggest width was measured in the contact point area. Results: Tables of mesiodistal widths of the permanent teeth and some equations were prepared. The measurement difference varied from 0 to 0.04 mm. the average value of difference was 0.016 mm with SD of 0.02 mm. All teeth in male are bigger than those in female and this different is most evident in canine teeth, especially the lower jaw canine teeth. Conclusions: At the end of this study an equation was found which was used to measure the total value of mesiodistal width of canine and premolar teeth of upper and lower jaws in a simple and exact way.

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

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

Predicting the size of unerupted canines and premolars using primary maxillary first molar

One of the most important aspects of interceptive orthodontic diagnosis and treatment planning is space analysis. To date all methods use the size of permanent teeth to predict the dimensions of unerupted teeth. The aim of this study was to predict the permanent teeth size using maxillary primary first molar. The size of primary maxillary first molars and permanent canines and premolars of 80 subjects was measured on their dental casts. Regression equations were determined between the size of primary maxillary first molars and permanent canines and premolars. The new regression equations for predicting permanent tooth size in the maxilla and mandible were, respectively, Y = 2.2X + 13 and Y = 2.4X + 9.5 among females and Y = 2.7X + 5.5 and Y = 2.4X + 9.5 among males. The results show that the primary maxillary first molar size can be used to predict the size of unerupted permanent teeth.

Using the Breeder genetic algorithm to optimize a multiple regression analysis model used in prediction of the mesiodistal width of unerupted teeth

For the prediction of the unerupted canine and premolars mesiodistal size, have been proposed different variants of multiple linear regression equations (MLRE). These are based on the amount of the upper and lower permanent incisors with a tooth of the lateral support. Aim of present study was to develop a method for optimization of MLRE, using a genetic algorithm for determining a set of coefficients that minimizes the prediction error for the sum of permanent premolars and canines dimensions from a group of young people in an area Romania's central city represented by Sibiu. To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers to which we adjusted regression coefficients using Breeder genetic algorithm proposed by Muhlenbein and Schlierkamp. A total of 92 children were selected with complete permanent teeth which had not clinically visible dental caries, proximal restorations or orthodontic treatment that requires the decrease of the mesiodistal size of teeth. For each of these models was made a hard dental stone which was then measured with a digital calliper, the instrument having an accuracy of 0.01 mm. To improve prediction equations, we divided data into training and validation sets. The Breeder algorithm, using the training set, will provide new values for regression coefficients and error term. The validation set was used to test the accuracy of the new proposed equations.

Odontometric Data and New Regression Equations for Predicting the Size of Unerupted Permanent Canine and Premolars for Chennai Population

Odontometric Data and New Regression Equations for Predicting the Size of Unerupted Permanent Canine and Premolars for Chennai Population

Odontometric Data and New Regression Equations for Predicting the Size of Unerupted Permanent Canine and Premolars for Chennai Population

Objectives : To produce odontometric data and formulate a new regression equation for prediction of unerupted canine and premolars in Chennai population. Materials and methods: The present study comprised of 400 study models (200 males and 200 females) obtained from Postgraduate Students of Department of Orthodontics, Saveetha Dental College, Chennai. The mesiodistal width of teeth from molar to molar in the maxillary and mandibular arches was measured using digital Vernier caliper and used to formulate the odontometric data and regression equation (to predict the width of unerupted canine and premolars). Results: The following are equations derived for prediction of unerupted canine and premolars in Chennai population: Males— Maxilla: y = 7.071 + 0.77x, Mandible: y = 6.430 + 0.650x; Females— Maxilla: y = 1.276 + 0.769x, Mandible: y = 7.388 + 0.605x Where, x = summed mesiodistal widths of the four mandibular incisors in millimeters, and y = estimated sum of mesiodistal widths of canine and two premolars in one arch quadrant, in millimeters. Conclusion: The observations obtained from our study would not only pave the way in predicting the mesiodistal width of unerupted canine and premolar in Chennai population but also give normative odontometric data which can be used for anthropological use and for diagnosis and treatment planning

Applicability of tooth size predictions in the mixed dentition space analysis in Nalgonda population

Aim: The aim of this study was to evaluate the applicability of the Tanaka-Johnston and Moyer's methods for predicting the size of permanent canines and premolars in Nalgonda population. Materials and Methods: 200 sets of dental casts (13-16 years) of the permanent dentition with no detected abnormalities were obtained from children attending in and around the schools of Nalgonda. The actual mesiodistal crown diameters were measured with digital vernier calipers (Zoom, Japan) to accuracy of 0.01 mm. The actual values were then compared with the predicted values derived from the Tanaka and Johnston equations and Moyer's probability tables. Correlation and linear regression analyses were performed between the predicted and the actual tooth size and standard regression equations were developed. Results: In the present study, Tanaka and Johnston regression equation overestimated the mesiodistal widths of permanent canine and premolars (P Conclusion: Tanaka and Johnston analysis overestimated the actual widths of the unerupted canines and premolars in the maxillary and mandibular arches of male and female subjects of Nalgonda population. New standardized regression equations were formulated for the prediction of the mesiodistal widths of unerupted canines and premolars. Moyer's prediction tables can be used at all probability levels for male and female subjects of Nalgonda.

Radicular cyst followed by incomplete pulp therapy in primary molar: A case report

Radicular cysts are one of the most common odontogenic cyst of the jaws. However, those arising from primary teeth are rare. An 8-year-old boy reported to the Department of Pedodontics and Preventive Dentistry with the chief complaint of pain and swelling on the lower left primary molar tooth region. Radiographic examination revealed a well-defined radiolucency with continuous hyperostotic border. Considering the age of the child, size of lesion, and involvement of unerupted premolars; marsupialization was preferred as a conservative treatment of choice. The success of the treatment was evident both clinically and radiographically during the follow-up period.

Estimation of the Crown Widths of Un-erupted Canine and Premolars by Using Vistibulo-oral Crown Dimensions of Per-manent Teeth

Estimation of the Crown Widths of Un-erupted Canine and Premolars by Using Vistibulo-oral Crown Dimensions of Per-manent Teeth

Experimental Formation of Dentin-like Structure in the Root Canal Implant Model Using Cryopreserved Swine Dental Pulp Progenitor Cells

ObjectivesThe purpose of the present study was to present histological and immunohistochemical evidence showing the regenerative capacity of swine dental pulp stem cells (S-DPSCs) seeded on organic or synthetic scaffolds and implanted as hybrid root implants in the jaw bone of minipigs. MethodsImmature permanent incisor teeth and unerupted premolars at the early root-forming stage were extracted from three 7-month-old minipigs, and mesenchymal stem/progenitor cells were isolated from dental pulp. Cells were cryopreserved in liquid nitrogen. A year later, new permanent incisor and premolar teeth were extracted; pulp tissue was removed; and pieces of root canals of the extracted teeth, containing collagen or Poly(lactic-co-glycolic acid) scaffolds seeded with the autologous cryopreserved DPSCs, were implanted into the fresh post-extraction socket of the mini pig jaw. The resulting constructs were harvested after 6 and 10 weeks and evaluated by histological and immunohistochemical analyses. ResultsSix weeks postoperatively, the central canal space of the root implants showed degrading scaffold material. New extracellular matrix had been deposited in a polar predentin-like pattern on the canal dentinal walls by cuboidal nonpolarized cells. Ten weeks postoperatively, newly formed organic matrix had been consistently deposited on the canal walls. The presence of a continuous layer of polarized cells showing typical columnar morphology adjacent to the newly deposited organic matrix was evident. ConclusionsThe interactions of S-DPSCs with the dentin matrix of roots implanted in the jawbone of minipigs constitute a model to study in vivo organization and differentiation potential of DPSCs.