Loss Of Molars Research Articles

Sequelae of premature loss of lower permanent molars on developing occlusion during the mixed dentition period-A radiographic evaluation.

When planning extraction of teeth with poor prognosis especially lower first permanent molars, it is important to consider the timing of tooth removal and its effect on future occlusion to avoid interventions.

Does corticotomy accelerate canine retraction with adequate anchorage control? A split mouth randomized controlled trial

ABSTRACT Purpose: To assess the effects of corticotomy on the distal movement of canine and to assess the amount of molar anchor loss. Materials and Methods: 14 patients were selected for this prospective, split-mouth, randomized controlled trial. After bilateral maxillary first premolar extractions, corticotomy was done distal to canine on one side and 150 g of force was applied. The rate of canine and molar movement, tipping and rotation were evaluated for control and experimental side. The movement of canine and anchor loss was assessed at an interval of 3 weeks, using study models, till single canine retraction was complete. Subjective assessment of the post-surgical pain, swelling, discomfort and an overall patient perception of the surgical procedure was assessed at two time points. Results: There was a significant increase in the rate of canine movement on the experiment side at T1 and T2 (p ≤ 0.01). Anchor loss was found to be present on both the sides but the difference was not statistically significant (p > 0.05). The mesiodistal tipping of canine was found to be greater on the control side than the experiment side whereas there was no statistically significant difference in the mesiodistal tipping of the molar on either side (p > 0.05). The experiment group showed a greater rotation of canine than the control (p ≤ 0.05), however, the rotation of molar was statistically insignificant. Conclusion: Corticotomy-assisted canine retraction causes a significant increase in the rate of canine retraction for the initial 2 months of the post-corticotomy period.

The relationship between ante‐mortem molar loss and mandibular ramus shape in an archaeological population from Korea

AbstractThe relationship between age, ante‐mortem tooth loss (AMTL) of molars, and mandibular ramus shape was examined in the context of function‐induced alteration. It was hypothesized that age, as well as molar AMTL, would be significant factors for predicting ramus shape variation in an archaeological skeletal sample from Korea. Mandibles of 90 adults from the Joseon Dynasty in Korea were analysed using 3D geometric morphometrics. Molars were counted as functional units when mandibular–maxillary occlusion would have been possible, and the tooth socket was not shallow and remodelled. The relationships among age, AMTL, and ramus shape were tested, and nonparametric multivariate (rank‐based) one‐way tests were conducted to test the effects of age and AMTL on mandibular shape, both with and without considering age and AMTL as factors, respectively. The results showed that AMTL had no significant effect on mandibular shape variation irrespective of whether age was considered (without age: p = .104; with age: p = .088). In contrast, age had a significant effect on mandibular shape variation when AMTL was also considered (p = .044). Most of the shape variation among age groups occurred in the mandibular regions where the main masticatory muscles insert. However, the effect of age on mandibular shape among individuals with all three molar functional units intact was not statistically significant (p = .221). Thus, it is clear that age alone cannot explain all of the variation in mandibular shape. Rather, the results suggest that age and AMTL are highly correlated and combine to affect mandibular ramus shape variation throughout ontogeny.

Prevalence of early loss of primary molars among schoolchildren aged 5–9 years in Bangalore city: A cross-sectional study

Introduction: Early loss of deciduous molars has a great impact on the development of the dentition. Psychological, morphological, and functional problems may result from premature loss. Thus, early recognition and management play a crucial rule in delivering effective dental treatment to the child patient. Aim: The purpose of the study was to evaluate the prevalence of early loss of primary molars in schoolchildren in Bangalore city, India. Materials and Methods: The study group included 200 children, that is, 115 boys and 85 girls. The dental examination was performed by an experienced examiner under sufficient natural light. Data including patient age and missing molars were collected, classifying the status of molars according to the WHO oral health assessment form for children (tooth). Collected data from each patient were subjected to statistical analysis to know the prevalence of early loss of primary molars. Results: The results showed that 31% of the sample had early loss of primary teeth with no statistically significant difference between genders. A higher prevalence was found among the 7–9-year-olds (69%), and the most commonly affected teeth were the right lower primary first molars (23%). Conclusion: The findings give an inference that untreated early childhood caries is the most common cause for early loss of primary molars resulting in occlusal discrepancy and functional problems. It is crucial to increase awareness among parents, pediatricians, and general dentists regarding the importance of primary teeth.

Marginal bone loss in the second molar related to impacted mandibular third molars: comparison between panoramic images and cone beam computed tomography.

Background Deciding whether or not to extract third molars remains a controversial situation in dental practice. Image exams support this decision by enabling a close view of the third molar, its adjacent bone and its relationship with the second molar. This study aimed to assess and compare second molar bone loss adjacent to impacted mandibular third molar in panoramic radiographs (PAN) and cone beam computed tomography (CBCT) scans. Material and Methods A sample of 70 patients was selected (n=124 teeth). Each patient had a set of a panoramic radiograph and CBCT scans consecutively taken for dental treatment purposes. In PAN and CBCT, mandibular third molars were classified based on their position and bone loss of the adjacent second molar. Agreement between PAN and CBCT scans was assessed and quantified. Results Outcomes of bone loss assessment were different between PAN and CBCT scans (p<0.05). Bone loss was found in 62.9% of the PAN, while in CBCT scans it was found in 80%. In particular, nearly 29% (n=27) of the teeth that were classified without bone loss in PAN were classified with bone loss in CBCT scans. Mesioangular and horizontal third molars had a statistically significant association with bone loss of the adjacent second molars (p<0.05). In general, PAN underestimated the severity of bone loss compared to CBCT scans (p<0.05). Conclusions Diagnosing second molar bone loss due to impaction of adjacent third molar in PAN may be challenging because of false negatives. Impacted third molars justify preoperative CBCT scans if second molar bone loss needs to be precisely assessed for a more detailed and reliable treatment plan. Key words:Bone, CBCT, panoramic radiograph, third molar.

Comparison of dual-dimensional and rectangular wires in terms of space closure and anchorage loss during retraction with miniimplants: A prospective clinical study.

Background. In sliding mechanics, archwires should slide easily during the retraction of anteriors. Round wires slide well, but the torque control is a significant problem. Rectangular wires produce effective torque expression but pose a challenge to free sliding due to factors like friction and force used to overcome friction, etc. To utilize the properties of both wires, the wire should be bi-dimensional. Dual-dimensional wire is one such wire with different dimensions in the anterior and posterior sections. This study aimed to compare the amount of space closure and anchorage loss of molars between the rectangular and dual-dimensional wire groups during retraction with mini-implants. Methods. Forty patients were randomly allocated to two groups (n=20). Patients with rectangular wires formed the control group, and those with dual-dimensional wires formed the experimental group. Mini-implants and NiTi coil springs were used for retraction. Model and cephalometric analyses were carried out to calculate the amount of space closure and anchor loss, before and four months after the study. Statistical significance was set at P<0.05. Results. The average amount of space closure was higher with DDW (3.98 mm) than rectangular wire (3.22 mm). The difference was statistically significant. No significant difference was found with anchorage loss. Conclusion. DDW can be used as an alternative to rectangular wires during retraction with mini-implants; however, it cannot replace the rectangular wires completely. Anchorage control was effective with both wires.

Avaliação da prevalência da perda precoce de molares decíduos na dentição mista

Objective: To assess primary molars early loss in mixed dentition prevalence. Method: A study was carried out in children aged 6 to 12 years. Deciduous molar loss was considered early when it occurred before Nolla stage 6 (full formed crown) of the permanent successor or one year before its physiological exfoliation. Periapical radiographs were obtained to verify the presence of the permanent successor and the level of root formation, as well as the need for placement of fixed space maintainer lingual arch or Nance button. For the study of frequency distribution of early dental loss in relation to gender and dentition, we used the Chi-square test of 5% probability level and the non-parametric Mann-Whitney test for adequate statistical analysis. Results: Of the 315 children examined, 159 (50.47%) were male and 156 (49.52%) were female. Only 25 (7.9%) presented multiple dental losses in the posterior region, 19 in the lower arch and 6 in the upper arch. In the inferior one there was predominance of first and second deciduous molars loss. There was no difference in the association between genders and the occurrence of multiple dental losses (χ² (1) = 0.03, p&gt;0.05). Conclusion: The prevalence of deciduous teeth premature loss was of 7.9% and the most affected teeth were the first and second molars in the lower arch. Lingual arch space holders were installed in 6 children, who will remain with it until the permanent successors erupt into the oral cavity.

Space maintenance for the premature loss of the second primary molar

Space reduction after the premature loss of the second primary molars is one of the important factors affecting the occurrence of malocclusion, often increasing the demand for orthodontic treatment. It has great significance to select and apply appropriate appliances to maintainthe space soon after the premature loss of the second primary molars. The space should be maintained until the adjacent teeth and the successors erupt successfully. This review summarizes the selection and clinical application of the space maintainer for the premature loss of the second primary molars in different periods, to improve dentists' awareness of the importance of space maintainers and to provide advises for clinical choices.

Patient-, tooth-, and dentist-related factors influencing long-term tooth retention after resective therapy in an academic setting-a retrospective study.

The aim of this study was to evaluate long-term (≥5 years) tooth survival after resective therapy of multi-rooted, periodontally treated teeth and investigate the influence of patient-, tooth-, and dentist-related risk factors on tooth loss. A total of 128 patients with root-resected molars were reexamined. Patient-, tooth-, and dentist-related factors were assessed. Tooth survival times were estimated using the Kaplan-Meier method in addition to a Cox proportional hazard frailty model with survival as the dependent outcome to assess an association with predictor variables. Overall, 100 patients with 130 molars were included. The average postoperative reevaluation period was a 9.62 ± 3.08 year showing an overall survival rate of 56.9% after resective therapy. A cumulative survival rate of 69% (95% CI (61%; 77%)) after 5 years decreasing to 48% (95% CI (35%; 61%)) after 15 years was detected. The median survival time of resected molars was 13.83 years (95% CI (8.75; ∞)). Adherence, smoking, and insurance status were detected to significantly influence the risk for loss of molars after resective therapy. Resective periodontal procedures can still be considered an option to retain periodontally compromised molars. In contrast to dentist- and tooth-related factors, patient-related factors impacted significantly upon tooth survival. Periodontally compromised molars could be retained in more than 50% of the cases thus prolonging their life span significantly. This information shall be valuable for clinicians in decision-making, treatment planning, and postoperative management. The weighting of resective therapy to implants especially with regards to the risk of peri-implantitis should be considered.

Tooth loss and multivariable analysis after 5-year non-surgical periodontal treatment on molars with furcation involvement

OBJECTIVE To evaluate the tooth loss status of mandibular molars with furcation involvements after 5-year non-surgical periodontal treatment, and to analyze the factors that affected the tooth loss. METHODS A retrospective analysis was conducted in 79 patients with chronic periodontitis, who had received non-surgical periodontal treatment and 5 years of periodontal maintenance treatment in Department of Periodontology, Peking University School and Hospital of Stomatology from 1988 to 2012. Their clinical indexes, including probing depth (PD), bleeding index (BI), furcation index (FI) and tooth mobility were both evaluated before treatment and at the last time of the maintenance treatment. Bone resorption at furcation area was measured at the first visit by periapical radiographs taken by professional doctors of medical imaging. The status of tooth loss after 5-year non-surgical periodontal treatment on mandibular molars with furcation involvement, and the factors that affected the tooth loss were analyzed. RESULTS (1) Non-surgical treatment was significantly effective on the changes of PD in the patients of chronic periodontitis with furcation involvement, while the presence of furcation involvement could affect the improvement of PD here. (2) PD at the furcation area, tooth mobility, vertical bone resorption, and bone resorption area were all significant risk factors of mandibular molar missing (P<0.001), and the same with FI=3 and FI=4 (P=0.017, P=0.007), while age (P=0.703), gender (P=0.243) and smoking history (P=0.895) were not related to the tooth loss in this study. (3) The risk of tooth loss in mandibular molars with FI≥3 were significantly higher than those with FI≤2, and the survival rate of the former was less than 50%. CONCLUSION The loss of mandibular molars with furcation involvement was related to the furcation involvement, meanwhile the degree of furcation involvement and bone resorption can significantly increase the risk of tooth loss.

Spatial changes in the dental arch after premature extraction of the first primary molar – a 12-month observational study

Introduction. Premature loss of the first primary molar may cause malocclusion or impair permanent tooth eruption. Aim. The aim of the study was to assess spatial changes in the dental arch after unilateral premature extraction of the first primary molar. Material and methods. The alginate impressions were taken in patients aged between 5 and 7 years who met the inclusion criteria based on medical history, clinical examination and panoramic x-ray during a preliminary qualifying examination 14 days before or on the day of extraction (before the procedure), as well as during follow up (at months 1, 3, 6 and 12 after extraction). Gypsum models were used to measure the circumference of the arch, the posterior and intercanine width, as well as the interdental distance: IIID-VM, IIID-VD on the side of extraction and the opposite side of the arch. The data were analysed statistically (Statistica 10, Statsoft, p &lt; 0.05). Results. A total of 14 mandibular and 16 maxillary teeth were extracted in 27 children aged between 5 and 7 years (mean age ± SD = 6.64 ± 1.01; 15 boys and 12 girls). A significant loss of interdental spaces for IIID-VM and IIID-VD between the study vs. control side due to distalisation of canine and mesialisation of the second primary molar was observed. Much less significant displacement of these teeth was noted in the case of the presence of the first permanent molar at the time of first primary molar extraction. Conclusions. Premature loss of first primary molars results in reduced interdental distances which does not hinder the eruption of their permanent successors. There is no need for space maintainers.

Deciduous tooth early loss prevalence in posterior region and indication of band-loop space maintainer

Aim: To investigate the prevalence of the early unitary loss of deciduous and the need for space maintainer in the posterior region, of the band-loop type. Methods: The clinical examination of 568 children between 6 and 12 years of age in mixed dentition was performed in two municipal schools. After the diagnosis of premature loss of one or two deciduous molars (unilateral, one or both arches, respectively), without successors initiating the eruptive process in the oral cavity, the child was referred to the Clinical School of Dentistry of UESPI (CSD ) for installation of the band-handle space maintainer. Results: The prevalence of early molar loss was 4.04%, the etiological factor of which was dental caries for all sample. Only 13 attended the CEO for detailed examination. After radiographic examination, it was verified that 8 did not need space maintainers because they were approximately 2/3 of the permanent successors root formation. In 5 children was placed the maintainer of space, band-handle, who are being supervised every 3 months until the eruption of the permanent successors. Conclusion: The prevalence of early premolar molar loss was 4.04% with no statistical difference between genders. The use of space maintainers after the early loss of a deciduous tooth is a preventive measure of malocclusion, being the band-loop appliance an excellent choice after loss of the deciduous unilateral molar.

Natural 4-year periodontal progression of mandibular first molars in Chinese villagers based on radiographic records.

To report 4-year natural periodontal progression of mandibular first molars based on radiographic records in 15 to 44-year-old Chinese villagers. In 1992 (N=486) and 1996 (N=413), panoramic radiographs were recorded. Tooth loss of mandibular first molars was calculated. Relative bone height (RBH), intrabony defect (IBD) depth, and furcation involvement (FI) were measured on 918 and 755 mandibular first molars in 1992 and 1996, respectively. The progression of the three parameters and their relationship with widened periodontal ligament space (WPDL) were analyzed. In 1992, of 31 lost mandibular first molars, 29 belonged to the 35- to 44-year age group. At 4-year follow-up, five of eight lost teeth belonged to the 35- to 44-year age group. RBH decreased from 83% in 1992 to 77% in 1996. RBH progression was significantly faster in the 25- to 34- and 35- to 44-year age groups than in the 15- to 24-year age group. The mean IBD depth was 2.81±0.55mm (n=32) in 1992 and 3.70 ± 0.73mm (n=33) in 1996. Prevalence of FI increased from 20.8% to 27.4%. Teeth with WPDL showed greater RBH and IBD progression than those without WPDL (RBH: 12%±1% versus 6%±0.01%, P < 0.001; IBD depth: 0.31±0.08versus 0.01±0.00mm, P <0.001). FI-area progression in teeth with WPDL showed a trend of greater expansion than in those without WPDL (0.92±0.18versus 0.56±0.11mm2 , P =0.051). Tooth loss mainly occurred in the 35- to 44-year age group. RBH progression was faster in the 25- to 44-year age group. WPDL was associated with progression of RBH, IBDs, and FI.

Influences of Masticatory Function Recovery Combined with Health Guidance on Body Composition and Metabolic Parameters

Background: Tooth loss reduces masticatory function. Insufficient masticatory function causes an increase in carbohydrate intake while decreasing the intake of foods with a low Glycemic Index (GI) and high in protein, antioxidants, dietary fiber, vitamins, and minerals. Protein-energy malnutrition may lead to metabolic syndrome, frailty, and faster onset of Non-Communicable Diseases (NCDs). Individuals with tooth loss resulting in problematic eating habits require behavior modification and health guidance. Objective: This report aims to evaluate the influence of dental prostheses combined with health guidance on body composition and metabolic parameters. Methods: Data were collected from three subjects: Two with molar loss and one with edentulism. Masticatory function was restored in each subject through prosthodontic treatment. Masticatory performance was evaluated before and after the prosthodontic treatment by having the subjects chew a gummy jelly and measuring the glucose extraction. Questionnaires were used to assess food intake and lifestyle habits. Health guidance based on the results of the questionnaires was conducted simultaneously with the prosthodontic intervention. Body composition and blood pressure were measured and blood tests were performed at baseline and around 90 days after the first health guidance session. Results: Masticatory ability, body-mass index, basal metabolism standard value, body-fat percentage, and intake of certain nutrients improved in all cases. Blood pressure and hemoglobin A1c improved in two cases. Conclusion: Masticatory function recovery combined with health guidance was effective in preventing the onset or deterioration of NCDs in patients with masticatory dysfunction.

Simultaneous Bilateral Intrusion of Supra-Erupted Maxillary Molars using Miniscrew Implants

The loss of lower molars often leads to over-eruption of the opposing maxillary molars, combined with insufficient clearance for lower prosthetic restorations. The available treatment options are either a significant reduction of the maxillary teeth, often associated with endodontic treatment, or removable appliances such as headgear which depend on patient compliance; a complex fixed orthodontic treatment, which may involve unwanted side-effects, or a segmental impaction involving all the risks of surgery and patient discomfort. In previous years, different cases of orthodontic intrusion with miniscrew implants have been described, which make use of four or more miniscrews for bilateral maxillary molar intrusion. In this report, a case is presented requiring bilateral maxillary molar intrusion in order to get sufficient space for an implant-supported fixed restoration in the lower posterior region. This intrusion was carried out simultaneously on both sides by means of three miniscrew implants and a customized transpalatal arch. The results showed significant intrusion of the supra-erupted maxillary molars with normal and acceptable biological response of the teeth and the surrounding bony structures. CPD/Clinical Relevance: This paper presents a case report demonstrating a new clinical technique to intrude supra-erupted maxillary molars simultaneously on both sides with the use of three miniscrew implants instead of the conventional four, and a customized transpalatal arch which is simple to fabricate. The technique shows effective results in terms of intrusion achieved and the absence of clinically detectable apical root resorption of the intruded molars.

Comparative evaluation of the maxillary canine retraction rate and anchorage loss between two types of self-ligating brackets using sliding mechanics.

OBJECTIVE:To evaluate the maxillary canine retraction rate and anchorage loss with active and passive self-ligating brackets (SLBs).MATERIALS AND METHODS:The study was conducted on 10 patients whose age ranged from 14–20 years. The patients had minimal to no crowding with a dental protrusion of maxillary incisor that required the extraction of maxillary first premolars and retraction of canines. The maxillary canines had to be in a good alignment and level before treatment to ensure that canine retraction had started from the same point bilaterally. A cone beam computed tomography (CBCT) had been taken for each patient's maxilla before treatment initiation and after complete canine retraction. Using nickel titanium, close-coil spring canine retraction on both sides and the rate of canine movement was measured.RESULTS:The patients were checked every 2 weeks to measure the retraction rate and ensure that a constant force (150 g) was being delivered to both canines. The pre- and post-canine retractions CBCT were superimposed to evaluate the pattern and rate of canine movement and anchorage loss. The result of this study showed no statistically significant difference between the two groups.CONCLUSION:The type of SLB, either active or passive, does not affect the rate or type of canine movement during its retraction in the orthodontic extraction cases, and the anchorage loss of the upper molars was nearly the same in both type.

Prevalence of early loss of primary molars among children aged 5–10 years in Chennai: A cross-sectional study

Prevalence of early loss of primary molars among children aged 5–10 years in Chennai: A cross-sectional study

ABO incompatible kidney transplantation: the Saudi experience.

Although the outcomes of ABO-incompatible (ABOi) kidney transplant recipients are quite favorable, these patients are at increased risk of early antibody-mediated rejection (AMR) and graft loss. Some studies have also shown high mortality in the ABOi group mainly due to increased risk of infections. The AMR rates have been reported anywhere from <10% to >50% in the literature. The outcomes of the ABOi kidney transplants in the Saudi population are not known. In this study, we aimed to determine the graft and patient survival in ABOi kidney transplant recipients in the Saudi population. We included all adult patients who underwent ABOi transplantation between 2007 and 2016. All patients received rituximab, therapeutic plasma exchange, thymoglobulin, intravenous antibiotics, and intravenous immunoglobulin. The maintenance immunosuppression was prednisone, mycophenolate mofetil, and tacrolimus. The data were collected from a prospectively maintained database. A total of 77 patients were included in the study. The most common blood group mismatch was A to O (44.2%), followed by B to O (26.0%) and A to B (16.9%). In the 1st year, 17% of patients developed acute cellular rejection and AMR occurred in 7.8% of patients. Two patients were diagnosed with BK nephropathy. In the 1st year, urinary tract infection occurred in 25 (32.5%) patients. No patient was diagnosed severe viral or fungal infection. In the 1st year, four grafts were lost (graft survival of 94.8%); all grafts were lost within two weeks, three due to AMR and one due to technical reason. One year patient survival was 100%. In this study of ABOi kidney transplant recipients, we observed low risks of infectious complications with excellent patient and graft survival. Our immunosuppressive protocol can be considered safe.

Comparison of anterior retraction and anchorage control between en masse retraction and two-step retraction: A randomized prospective clinical trial.

The purpose of this two-arm parallel trial was to compare en masse (ER) and two-step retraction (TSR) during space closure. Forty-eight adult patients with bimaxillary protrusion who were planned for treatment with extraction of four first premolars were enrolled. All patients were randomly allocated in a 1:1 ratio to either the ER (n = 24) group or the TSR (n = 24) group. The main outcome was the amount of posterior anchorage loss in the molars and the retraction of the incisors between ER and TSR; the difference in incisor and molar inclination was a secondary outcome. Lateral cephalometric radiographs and oblique cephalometric radiographs at 45° were taken before retraction (T1) and after space closure (T2). Cephalograms were digitized and superimposed on the anatomic best fit of the maxilla and mandible by one operator who was blinded to the treatment group. Neither incisor nor molar crown movements showed any significant differences between the ER and TSR. There were no significant differences in the tipping of incisors and molars between the two groups. No significant differences existed in the amount of retraction of incisors and anchorage loss of molars between ER and TSR. Changes in incisor and molar tipping were similar, with the crowns showing more movement than the apex.

Craniodental Allometry, Prenatal Growth Rates, and the Evolutionary Loss of the Third Molars in New World Monkeys.

A growing body of literature demonstrates that genetic patterning mechanisms underlie the relative proportions of the mammalian postcanine dentition with the third molar being key to understanding variation within the molar row. With this relatively recent insight, there has been renewed interest in mammalian taxa that have lost the third molars. Within platyrrhines, the marmosets and tamarins (Callitrichidae family) are characterized by small body size, claw-like nails, twinning, and reduced molar number. Small body size is hypothesized to have resulted in the third molar being crowded out of the jaws leading to its evolutionary loss in this family. To further explore this hypothesis, we measured the cranium and dentition of 142 individuals spanning all five platyrrhine families. These data reveal that callitrichids have a significantly smaller proportion of mandibular postcanine tooth row length relative to other platyrrhines, refuting the "crowding out" hypothesis. However, postcanine tooth row length is significantly correlated with mandibular length and cranial length (P < 0.01) across all platyrrhines providing evidence for a strong allometric association between postcanine tooth row length and body size more generally. The small body size that characterizes callitrichids results in part from slower prenatal growth rates. Given the allometric relationship between postcanine tooth row length and body size, reported here and in previous studies, we hypothesize that the evolutionary loss of the third molars in callitrichids results from the inhibition of third molar development as a consequence of the slower prenatal growth rates associated with small body size in this family. Anat Rec, 302:1419-1433, 2019. © 2018 Wiley Periodicals, Inc.