PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “MOLAR”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1989

Clinical effects of root debridement in molar and non-molar teeth. A 2-year follow-up.

12 patients were studied longitudinally to monitor the effects of basic periodontal therapy in molar and non-molar teeth. Periodontal sites were grouped into molar furcation sites, molar flat-surface sites and non-molar sites. Clinical measurements were taken at baseline and directly followed by full mouth root debridement. Subsequently, measurements were taken every 3rd month until 24 months. At each of these appointments, the patients were monitored for their oral hygiene performance and given supragingival prophylaxis. The mean results indicated that initially moderately deep and deep molar furcation sites responded less favorably to therapy compared to non-molar sites and molar flat-surface sites of similar probing depth. Initial improvements in probing measurements for moderately deep and deep molar furcation sites were limited and also tended to revert during the observation interval. Identification of individual sites with probing attachment loss disclosed that 25% of molar furcation sites lost probing attachment as compared to 7% for non-molar sites and 10% for molar flat-surface sites. These results corroborate previous findings and call for additional or alternative treatment regimens for periodontal furcation pockets.

Adult↗
PubMed1990

Eruption of mandibular third molars after second-molar extractions: a radiographic study.

The purpose of the present study was to analyze the posteruptive contact relationship and inclination of mandibular third molars after extraction of second molars and to determine whether predictors could be formulated for the dental relationships observed. In all, 140 mandibular quadrants were evaluated from 95 sets of panoramic radiographs taken at the time of second molar extraction (T1) and at the time of final evaluation (T2). For analysis of a consecutive sample of patients, a subsample of 25 sets of radiographs from all the patients who had received such treatment during one calendar year was also quantified. Subjective evaluation indicated that 46% of the sites examined had satisfactory tooth contact relationship between the first and third molars at T2. Third-molar impaction was found in 4% of the sites in the subsample of 25 consecutively treated patients. Measurements of crown axis inclination revealed that the third molar invariably erupted into a mesially tilted position. The first molar showed only minor distal tipping between T1 and T2. Inclination of the third molar bud at the time of second molar extraction was not found to be a useful predictor for posteruptive third molar position. The clinical significance of these results and the need for studies regarding a rationale for mandibular second molar extraction are discussed.

Adolescent↗
PubMed2005

Effects of lower third molar extraction on attachment level and alveolar bone height of the adjacent second molar.

Several conflicting findings have been published in previous literature regarding the effects of impacted third molar extraction on the periodontal health of the adjacent second molar; some authors have shown improvement of periodontal health distal to the adjacent second molar, whilst others have demonstrated loss of attachment and reduction of alveolar bone height. The purpose of this controlled clinical and radiographic study is to evaluate the long-term changes in periodontal health and alveolar bone height distal to the adjacent second molar following extraction of an impacted third molar. This split-mouth design study included 25 patients who underwent extraction of one mandibular impacted third molar (test), whereas the opposite tooth remained intact (control). Pre-operative and current-state panoramic radiographs were than scanned, and alveolar bone height was digitally measured on the distal aspect of the second molar on the test and control sides. Current-state clinical measurements were performed on both sides, and consisted of plaque index, gingival index, periodontal pocket depth, gingival margin position and clinical attachment level. Student's t-test for paired observations was used in order to examine the statistical significance of the differences in clinical parameters between the test and control sides and the differences in alveolar bone height pre- and post-operatively on both sides. Extraction of an impacted third molar resulted in a significant gain of alveolar bone height on the distal aspect of the adjacent second molar on the test side, whereas slight bone loss was noted on the control side. Even though the difference in plaque index between the test and control sides approached statistical significance following extraction, all clinical parameters seem to be unchanged. Further follow-up on clinical and radiological parameters is required for a more profound understanding of the long-term effects of third molar extraction on the periodontal health of the adjacent second molar.

Adult↗
PubMed1998

Eruption and function of maxillary third molars after extraction of second molars.

After extraction of maxillary second molars, will the third molars erupt into a functional position in a timely manner? To answer this question, 56 consecutively treated cases of maxillary second molar extraction were reviewed. The unerupted positions of the maxillary third molars were measured on cephalometric radiographs, ages of eruption were evaluated, positions of erupted third molars analyzed, and interproximal periodontal health of adjacent first molars compared. The results showed that, generally, the eruption of third molars was accelerated. Most of the third molars had acceptable interarch and intra-arch occlusal relationships. The interproximal periodontal health of the third molars was similar to that of adjacent first molars. Most maxillary third molars will successfully erupt into an acceptable position by the late teens.

Adolescent↗
PubMed1985

Surgical removal of the fully impacted mandibular third molar. The influence of flap design and alveolar bone height on the periodontal status of the second molar.

This study was carried out because a great deal of uncertainty exists as to he effect of the surgical removal of the fully impacted third molar on the periodontal status of the second molar. The objectives were to determine the effect of surgical removal of the third molar on the periodontal status of the second molar; the influence of flap design on these results; the influence of the initial height of the alveolar bone on the distal of the second molar on subsequent changes in attachment level. The study included 30 patients with bilateral mandibular impactions. A split-mouth experimental design was used, with one side of the mandible being randomly allocated to one of two flap design groups. Plaque level, gingival inflammation, probing depth and attachment level measurements around the second molar were taken at baseline and then at monthly intervals for a period of 6 months. Alveolar bone height was measured from panoramic radiographs. Six months postsurgically, both flap design groups exhibited a statistically significant loss of attachment level on the distal surface of the second molar with no difference between the two flap groups. The initial height of the alveolar bone on the distal of the second molar had no influence on the loss of attachment. It was concluded that the surgical removal of the fully impacted mandibular third molar led to the loss of attachment on the distal of the second molar; flap design had no influence on the degree of attachment loss; the initial height of the alveolar bone on the distal of the second molar had no influence on the loss of attachment.

Adolescent↗
PubMed1990

[Root resorption of mandibular second molars by impacted third molars. A case report with some reviews].

A case is presented here in which mandibular third molars resorbed second molars bilaterally 4 years 9 months after orthodontic treatment was finished. The initial problem was open bite, which was treated by non-extraction followed by a period for observing the third molars. During that period, the mandibular third molars moved mesially to resorb the roots of the second molars. The injured second molars were, therefore, extracted and the third molars were uprighted. During adolescence, third molars are erupting. When the posterior space is not enough for the third molars, they often erupt buccally or lingually, or impact distally toward the second molars and cause root resorption. It is suggested that the third molars should be observed carefully till they erupt or are extracted.

Adolescent↗
PubMed2006

Progression of periodontal disease in the second/third molar region in subjects with asymptomatic third molars.

PURPOSE: To assess the change in periodontal status over time by periodontal probing depth (PD) in the third molar region. SUBJECTS AND METHODS: The data for these analyses are part of a study of subjects enrolled with 4 asymptomatic third molars with adjacent second molars in an institutional review board-approved longitudinal trial. Full mouth periodontal probing was conducted to determine periodontal status at baseline and follow-up. Panoramic radiographs were analyzed for angulation and degree of eruption of third molars. Subjects were categorized as those who exhibited at least a 2 mm change in periodontal PD between baseline and follow-up in the third molar region, the distal of a second molar or around a third molar, and those who did not exhibit a 2 mm or greater change. Subjects with and without changes in PD were compared with Cochran-Mantel-Haenzsel statistics. Level of significance was set at 0.05. RESULTS: Data from 254 subjects with at least 2 annual follow-up visits were available for analysis. Mean age at baseline was 27.5 years. Median follow-up from baseline to the second follow-up visit was 2.2 years (interquartile range 2.0, 2.6). At enrollment, 59% of the subjects had at least 1 PD > or =4 mm in the third molar region, one quarter had a PD > or =5 mm. Twenty-four percent of the subjects had at least 1 tooth that had an increased PD > or =2 mm in the third molar region at follow-up. If subjects had at least 1 PD > or =4 mm at baseline, 38% had at least 1 PD deepen by 2 mm or more at follow-up. Only 3% of those who had all teeth with a PD of less than 4 mm at baseline exhibited a change of > or =2 mm (P < .001). CONCLUSION: Increased periodontal PDs > or =2 mm were often found in the third molar region for asymptomatic subjects with at least 1 PD > or =4 mm at enrollment, clinical measures that indicated increased periodontal pathology, and a deteriorating periodontal condition.

Adolescent↗
PubMed2002

Residual periodontal defects distal to the mandibular second molar 6-36 months after impacted third molar extraction.

AIM: This retrospective study investigated the periodontal conditions distal to mandibular second molars 6-36 months after routine surgical extraction of adjacent impacted third molars. METHOD: Subjects were randomly selected by systematic sampling from computer records of 3211 surgical mandibular third molar extractions in the Hong Kong dental teaching hospital. Records and pre-extraction radiographs of the selected cases were retrieved. Selected subjects (n = 283) were invited for an interview followed by a clinical examination. Community Periodontal Index (CPI) protocol was used for the assessment of the general periodontal status (excluding the mandibular second molar of interest, i.e. the subject tooth) followed by a detailed periodontal examination of the subject tooth. RESULTS: In all, 158 subjects, aged 29 +/- 7 years, were examined with only 6% (nine subjects) having a highest CPI score of 4 (excluding the subject tooth), but local periodontal defects were prevalent at the distal surface of subject mandibular second molars: mean probing pocket depth (PPD) was 5.4 +/- 1.9 mm with 67% (106 subjects) exhibiting PPD >or= 5 mm and 23% (36 subjects) exhibiting PPD >or= 7 mm; mean recession was 0.8 +/- 1.0 mm; bleeding on probing 96% and suppuration on probing 5%. Multiple linear regression analysis was used to analyse the effects of 12 independent variables on the PPD at the distal surface of the involved mandibular second molar. Three possible risk indicators (P < 0.001, R2 = 0.27) associated with localised increased PPD at the distal surface of the mandibular second molars were identified: 1) third molar 'mesio-angular' impaction; 2) pre-extraction crestal radiolucency and 3) inadequate post-extraction local plaque control. CONCLUSION: The results suggest that periodontal breakdown initiated and established on the distal surface of a mandibular second molar in the vicinity of a 'mesio-angular' impacted third molar evidenced by pre-extraction crestal radiolucency in association with inadequate plaque control after extraction can predispose to a persistent localised periodontal problem.

Adolescent↗
PubMed2005

A regimen of systematic periodontal care after removal of impacted mandibular third molars manages periodontal pockets associated with the mandibular second molars.

AIM: This randomized, single-blinded control trial investigated the local effects of periodontal care on the mandibular second molar delivered during and after impacted third molar surgical extraction. METHOD: Thirty subjects (50% male, 32.1+/-7.8 years) out of 35 enrolled, with a mesio-angular impacted mandibular third molar, having probing pocket depth (PPD) >5 mm at adjacent second molar distal, and crestal radio-lucency between the two teeth, completed the study. Oral hygiene instruction, scaling and caries stabilization were performed before surgery. Controls (n=16) had their third molar extracted followed by standard socket debridement. Test group subjects (n=14) received the same treatment, except that before wound closure the operator was informed of the group allocation and ultrasonic root debridement on the second molar was performed, followed by a three-visit plaque control programme. RESULTS: Six months post-extraction, statistically significantly (p<0.007) better plaque control and shallower probing depths were observed at test second molars' distal (%plaque=21; PPD=3.2+/-1.2 mm) than at control second molars (%plaque=88; PPD=5.2+/-0.7 mm). CONCLUSIONS: The periodontal interventions investigated prevented residual pockets on periodontally involved second molars 6 months after ipsilateral impacted mandibular third molar removal.

Adult↗
PubMed1996

The effects of extracting upper second permanent molars on lower second permanent molar position.

There is some controversy over whether the extraction of upper second permanent molars as part of orthodontic treatment leads to the over eruption of unopposed lower second permenent molars. A study was established to investigate the presence of any over-eruption in a group of subjects who had upper second permanent molars extracted as part of a previous course of orthodontic treatment. These subjects (the experimental group) were compared with a control group of subjects, matched for age and sex. Upper and lower impressions were taken, and the vertical positions of the posterior teeth were objectively assessed from the study models using the travelling microscope. Measurements from the study models showed that the distal aspect of the lower second permanent molar had over erupted in the experimental group when compared to the control (P < 0.001 right, P < 0.05 left). The degree of over-eruption was influenced on the mesial aspect by the distal position of the upper first permanent molar (P < 0.01), but the distal aspect was not. Eruption of the upper third molar did not affect the over-eruption of the lower second permanent molar in the experimental group. The majority of upper third molars had erupted at least 3 years since the upper second molars had been extracted, but the majority had erupted into an unfavourable contact position with the first permanent molar.

Adult↗
PubMed1998

Morphometric analysis of developing crowns of maxillary primary second molars and permanent first molars in humans.

The purpose of this study was firstly to characterize the changes occurring in size and form of the mineralizing maxillary second primary molar and first permanent molar crowns, and secondly to determine if similar changes in size and form characterize enamel apposition in the crowns of these teeth. Twenty-five primary second molars and 20 maxillary permanent first molars at various stages of development, found in archaeological excavations in Israel, were examined for a number of measured variables using image analyser software. Teeth were divided into two groups according to their stage of development: stage I included all teeth at an early stage of development in which mesiobuccal-cusp height was less than 5 mm for the primary molar and 5.9 mm for the permanent molar; stage 2 included all teeth in later stages of development where mesiobuccal-cusp height was greater than these values. In the primary molar, a significant increase was found between the two stages in almost all variables. Significant correlations were also found between all intercusp distances and the external variables. Strong correlations between height of the mesiobuccal cusp and all external and internal variables were noted in stage 1, but fewer in stage 2. In the permanent tooth, no increase was observed in intercusp distances and very few correlations were found between and among the variables. The results suggest that a change in the shape of the maxillary primary second molar occurs during formation, with the lingual cusp tips moving lingually and distally, and the distobuccal cusp tips moving distally. No change occurs in the shape of the maxillary permanent first molar during crown formation. Growth of the maxillary primary second and permanent first molar crowns occurs in 'bursts' of development.

Age Determination by Teeth↗
PubMedDate not supplied

Preventing the transfer of Streptococcus mutans from primary molars to permanent first molars using chlorhexidine.

PURPOSE: The purpose of this study was to determine if the application of 1% chlorhexidine-containing wax on primary molars during the period of eruption of the first permanent molars could prevent the transfer of certain oral flora, namely Streptococcus mutans, to the permanent molars. METHODS: Fourteen children with a mean age of 6.5 years (7 males and 7 females) were assigned into two groups: a chlorhexidine group (n=9) in which 1% chlorhexidine-containing wax was painted on primary molars on one side of the mouth; and a placebo wax group (n=5) in which a similar wax, but without chlorhexidine, was painted on primary molars on the other side of the mouth. Baseline saliva samples and pooled plaque samples from the primary molars on both sides of the dentition were obtained from the two treatment groups. Following treatment, plaque samples from the occlusal fissures of the first permanent molars on both sides of the dentition were obtained. The levels of S.mutans and other members of the oral flora on the treated sides (chlorhexidine or placebo) were compared with those on the untreated sides. RESULTS: The results showed that the proportions of S.mutans to S.sanguinis were significantly lower in the chlorhexidine-treated sides compared to the untreated (P=0.04) and in the chlorhexidine-treated patients compared to placebo (P=0.029). CONCLUSIONS: Since lower mutans to sanguinis ratios have been associated with lower caries experience, treating primary molars with 1% chlorhexidine wax during eruption of permanent first molars may be a simple means for shifting the fissure flora of the permanent molars towards a more favorable balance.

Administration, Topical↗
PubMedDate not supplied

Development of caries in permanent first molars adjacent to primary second molars with interproximal caries: four-year prospective radiographic study.

PURPOSE: This study investigated the effect of the primary second molars' distal surface caries on the incidence of the permanent first molars' mesial surface caries in 613 paired tooth surfaces of children ages 6 to 8 years at baseline examination. METHODS: Proximal caries and its progression were diagnosed by bite-wing radiographs taken at a 1-year interval over a period of 4 years. The permanent first molars' mesial surfaces and primary second molars' distal surfaces were examined. Recorded were: (1) sound surfaces; (2) carious lesions on the enamel's external and internal half and on the dentin's external, middle, and internal third; (3) filled, extracted, and exfoliated teeth. The logistic model for panel data was employed to estimate the effect of proximal caries of the primary second molars' distal surfaces on the incidence of the permanent first molars' mesial surface caries. The 95% confidence interval probability was used. Sensitivity and specificity as well as the positive and negative predictive rates were computed. RESULTS: The results showed that the presence of proximal caries on each primary second molars' distal surfaces significantly affected the development of proximal caries on the corresponding permanent first molar's mesial surfaces. Age was estimated to exert a positive and highly significant impact, while gender had no effect. The odds ratio values ranged from 4.86 to 63.43. The values of sensitivity and specificity ranged from 45% to 97% and 80% to 89%, respectively, while the positive and negative rates ranged from 40% to 56% and 90% to 99%, respectively. CONCLUSIONS: Proximal caries present on the primary second molars' distal surfaces increases the risk of developing caries on the permanent first molars' mesial surfaces. This risk, however, is different among the paired surfaces studied.

Age Factors↗
PubMed1997

The rotation of maxillary first molars, mandibular first molars, and maxillary first premolars in acceptable occlusions.

The rotation of the maxillary molars is considered important in the orthodontic treatment of malocclusions. In this study, a computer analysis program was developed to examine the rotations of maxillary molars, mandibular molars, and maxillary first premolars in casts of permanent dentitions with acceptable occlusions. Ninety-three sets of untreated 'acceptable occlusion' models from the collection of the Foundation for Orthodontic Research (FOR) were scanned on a flat bed scanner. The images were analysed using custom software. Measurements were made by relating maxillary first permanent molars to the midline, archform, opposite canine, and mandibular first permanent molars. The mandibular first molars and maxillary first premolars were also analysed and their rotations measured. The mean rotations of the maxillary first molars, measured as the angle between a line joining the tips of the buccal cusps and a line tangent to the appropriate archwire form (from Ricketts' Pentamorphic Arches) at the first molars, were 0.59 and -0.72 degree (positive values represent mesio-lingual rotations) for the right and left, respectively. For the mandibular molars, these means were 6.34 and 8.40 degrees, respectively. The mean differences in rotation between buccal cusp tips of maxillary and mandibular first molars in occlusion were 5.75 and 9.12 degrees for the right and left, respectively, with the mandibular being more mesio-lingually rotated. The differences between left and right were significant for all measurements. The present study brings into question the suitability of our present "straight wire" prescriptions in producing similar occlusions. It also suggests that scanning models for computer analysis may be a practical and precise way to measure similar rotations in untreated normal and treated occlusions.

Analysis of Variance↗
PubMed2005

Distal cervical caries in the mandibular second molar: an indication for the prophylactic removal of the third molar?

AIMS: Distal cervical caries (DCC) in mandibular second molar teeth are responsible for the removal of up to 5% of all mandibular third molars. Our aim was to identify the clinical features of these patients. METHODS: We evaluated the records of 100 patients who had 122 mandibular third molars removed because of distal cervical caries in the second molar. RESULTS: Eighty-two percent of third molars had a mesial angulation of between 40 degrees and 80 degrees. The peak age for removal of third molars was 5 years later than in other studies and patients had better dental health than average. The incidence of distal cervical caries DCC has been shown to increase with age. CONCLUSION: Distal cervical caries is a late phenomenon and has been reported only in association with impacted third molars. The early or prophylactic removal of a partially erupted mesio-angular third molar could prevent distal cervical caries forming in the mandibular second molar.

Adolescent↗
PubMed2003

Topographic study of extracted molars with advanced furcation involvement: furcation entrance dimension and molar type.

This study investigated the topography of the furcation entrance dimension (FED) on molars with advanced furcation involvement (FI). The sample pool consisted of 169 maxillary and mandibular molars from a group of 165 individuals with severely advanced periodontal destruction. The subjects included men and women aged 24 to 84 years (mean, 47.8 +/- 7.2 years). The FEDs of the maxillary buccal, mesial, and distal surfaces as well as the mandibular buccal and lingual surfaces were measured under a stereomicroscope and clarified into grades I (FED < 0.55 mm), II (0.55-0.75 mm), and III (> 0.75 mm) using automatic grading system software designed by our research associates. The differences and relationships among molar location, furcation site, and FED grade were analyzed using the chi-square test. There was a significant difference among buccal (BFED), mesial (MFED), and distal (DFED) FEDs in both the maxillary first (chi2(4) = 58.915, p < 0.001) and second (chi2(4) = 66.839, p < 0.001) molars. The relationship between molar type and FED grade was statistically significant for both the BFED (p < 0.001) and the DFED (p < 0.001) of maxillary molars, as well as for both the BFED (p < 0.0001) and LFED (p < 0.0001). The difference in FED grade between the first and second molars was statistically significant in both maxillary (p < 0.001) and mandibular (p < 0.0001) molars. There was a significant relationship between FED grade and tooth location at molars with advanced FI.

Adult↗
PubMed1990

[Impacted bilateral first permanent molars induced by the migrated second permanent molars].

It is a relatively common clinical experience to see an impacted permanent tooth. In most cases, the cause is considered to be the existence of a supernumerary tooth or developmental crowding, but occasionally, the impacted tooth may occur with no apparent cause. The tooth most frequently impacted in the dental arch is a maxillary permanent canine or the third permanent molar, but the occurrence of the first permanent molar is an extremely rare situation. The patient, an eight-year, seven-month-old male was referred to the Pediatric Dentistry Clinic at the Higashi-Nippon-Gakuen University, School of Dentistry, for a detailed dental examination of his impacted lower permanent first molars. The oral findings through dental examination revealed that the bilateral upper first permanent molars were erupted, while the lower ones showed no clinical signs of eruption. Radiographic examination revealed that the lower second permanent premolars placed under the distal root of the second deciduous molars, and the first molars, inclined to the mesial position, placed at the under the second premolars bilaterally. There was nothing particular in his medical and dental history during the "teething" period. The authors determined that the cause of this impacted condition for the first molars seemed to be induced by a migration of an unerupted second permanent premolars. After extraction of the second deciduous molars and second permanent premolars, orthodontic therapy was undertaken in an attempt to move the impacted first molars into the arch.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗