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At least 523 records · Page 29Linked to original sources
PubMed1999

Eruption disturbances of the first and second permanent molars: results of treatment in 43 cases.

Impaction or retention of first and second permanent molars is an uncommon condition with diverse therapeutic approaches. To ascertain the success rate of different treatment possibilities, a retrospective study was made of 25 patients with a total of 43 permanent molars with eruption disturbances. In most cases, the nonerupted teeth were mandibular second molars (65%), followed by maxillary second molars (21%). Their position, degree of impaction (inclusion), clinical features, repercussion on the neighboring teeth, type of treatment, and outcome were evaluated. Infraocclusion was often associated with malposition of neighboring teeth, as well as extrusion and infraocclusion of opposing teeth. Due mostly to a delay in the diagnosis of the condition, an acceptable final position of the nonerupted molar was obtained in only 8 of 13 conservatively treated second molars. In order to prevent this situation, radiographic examination (ideally during the early mixed dentition period) and early diagnosis of eruption disturbances of permanent first and second molars are recommended, particularly when considering that these anomalies are associated with a high rate of occlusal disturbances that may require orthodontic correction.

Adolescent↗
PubMed1989

The fate of impacted lower third molars after the age of 20. A four-year clinical follow-up.

Seventy dental students (mean age: 20 years) with 130 asymptomatic, non-ectopic, impacted mandibular 3rd molars were followed for 4 years. At the initial visit 26 were impacted in soft tissue, 30 were partially impacted in bone, and 74 were completely impacted in bone. The following items were registered at each visit: regional pocket depths, signs and symptoms of pathology, degree of impaction, presence of upper 3rd molar. No signs or symptoms of pathology were observed in any of the subjects at the 2 visits. The 4-year visit revealed that 49 3rd molars had been removed, the reason being pericoronitis or caries in 30%, mild symptoms in 39% and for prophylactic reasons in 31%. Of the remaining 81 3rd molars: 71% of the soft tissue impactions, 25% of partial bony impactions, and 8% of complete bony impactions showed complete and normal eruption. The remaining 3rd molars were either static or had advanced in the degree of eruption. It is concluded that non-ectopic, impacted 3rd molars in the given age group may have a chance to completely erupt. The treatment for asymptomatic impacted 3rd molars in young adults, therefore, might be observation instead of prophylactic removal.

Adult↗
PubMed1995

Relationship between fractures of the mandibular angle and the presence and state of eruption of the lower third molar.

OBJECTIVES: This study attempted to relate the incidence of fractures at the mandibular angle with the presence and state of eruption of lower third molars. STUDY DESIGN: The records and radiographs of 200 patients with mandibular fractures were examined. The presence and degree of impaction of lower third molars were assessed for each patient and related to the occurrence of fractures of the mandibular angle. Data were analyzed by chi-square statistic and the Student's t test. RESULTS: The incidence of angle fractures was found to be significantly greater when unerupted lower third molars were present (p < 0.001). Bilateral unerupted third molar teeth predisposed to a fracture at the angle significantly more than unilateral unerupted third molars (p < 0.01). Furthermore, the amount of bony space occupied by an unerupted third molar tooth directly related to the weakness of that area of bone (p < 0.001). CONCLUSIONS: This study provides clinical evidence to suggest that unerupted third molar teeth weaken the mandibular angle both quantitatively and qualitatively.

Adolescent↗
PubMed2004

Contributions of reformatted computed tomography and panoramic radiography in the localization of third molars relative to the maxillary sinus.

OBJECTIVE: The aim of this clinical study was to seek an answer to the question of whether CT gives better qualitative and quantitative information as compared to panoramic radiograph when deciding on extraction of upper impacted third molars. STUDY: The study concerned 34 third molars appearing in direct relation with the sinus on the panoramic radiograph for which a CT scan had been recommended. For each case, the panoramic radiograph was compared with the CT scan for 5 evaluation criteria. RESULTS: The CT scan was more precise than the panoramic radiograph by 1.67 mm for measurement of the level of impaction of the third molar, by 12.44 degrees for measurement of the third molar displacement, by 0.74 mm for bone height separating the third molar roots and the sinus, and by 2.26 mm for the length of roots in the sinus. The CT scan was equally accurate for measurement of the distance separating the crowns of second and third molars in 34 cases. CONCLUSIONS: This study confirms the gain in precision for the CT scan as compared with conventional techniques. The CT scan therefore presents advantages when considering the extraction of upper third molars by providing both qualitative and quantitative information liable to bear on the diagnosis and therapeutic management.

Adolescent↗
PubMed2000

A study on the imaging of complex furcation forms in upper and lower molars.

BACKGROUND, AIMS: The form of the molar roots and their furcated region influence both the pathogenesis of periodontal destruction and therapeutic attempts. METHOD: Using a specially-constructed measuring device, 359 1st and 2nd molars, both upper and lower, were analysed 3-dimensionally. The parameters measured were horizontal furcation concavity, height of root trunk, degree of root taper, the distance between the root prominences adjacent to the furcation entrances and the angle of root separation. RESULTS: The mean horizontal furcation concavity in lower molars was 0.5 mm at a distance of 1 mm apical to the cemento-enamel-junction (CEJ) and 3 mm at the distance of 4 mm apical to the CEJ. The angle of root separation was between 16 degrees (lower jaw molars lingual) and 29 degrees (upper jaw molars distal). The vertical distance from root separation to CEJ averaged 3.3 mm in lower jaw molars and 4.8 mm in upper jaw molars. CONCLUSIONS: Our findings underline the variability of furcation morphology.

Anatomy, Cross-Sectional↗
PubMed2001

Dentists' decisions on prophylactic removal of mandibular third molars: a 10-year follow-up study.

OBJECTIVES: In recent years, several critical outcome studies concerning the prophylactic removal of mandibular third molars have been published. These would appear to motivate a more restrictive approach today as compared with 10 years ago. The aim of the present study was to examine dentists' decisions on the prophylactic removal of impacted mandibular third molars over a 10-year period. METHODS: Thirty-six cases were selected so as to represent an equal distribution of males and females, ages, angular position and degree of impaction of the molar. Twenty-six general dental practitioners (GDPs) and 10 oral surgeons judged the same cases on two occasions 10 years apart. RESULTS: Calculated for each category of dentists, there was no significant difference in the mean number of molars designated for removal between the two occasions. Two GDPs and three oral surgeons presented a higher removal rate, whereas five GDPs presented a lower removal rate on the second occasion as compared to the first one. The dentists presented a considerable interindividual variation in removal rate, between 0 and 22 molars on the first occasion and between 0 and 25 molars on the second occasion. CONCLUSION: In the decisions on prophylactic removal of mandibular third molars, there has been no change over the last 10 years towards a more noninterventionist attitude. Thus, the dentists seem not to have been influenced by the evidence that this intervention is not cost-effective.

Adult↗
PubMed2003

Effects of maxillary molar intrusion on the nasal floor and tooth root using the skeletal anchorage system in dogs.

The skeletal anchorage system (SAS) was developed to provide intraoral absolute anchorage for the intrusion or distalization of molars. The purpose of this study was to verify the effects of remarkable molar intrusion on the tooth root and the maxillary sinus floor. Six adult female beagles with fully erupted dentition were used. Titanium miniplates were implanted bilaterally above the maxillary second premolar root apices using pentobarbital anesthesia. The second premolars were intruded for four or seven months after three months of healing after implantation. Standardized dental radiographs were taken periodically to evaluate the amount of tooth movement and root resorption. After the experimental animals were fixed by perfusion at the end of each experimental period, the second premolars were dissected along with the surrounding alveolar bone. Undecalcified (60 microm thick) and decalcified (five microm thick) sections were prepared. The average extent of intrusion was 1.8 mm after four months and 4.2 mm after seven months. The root apices of the intruded molars penetrated into the nasal cavity. Remodeled bone around the intruded molar toots was rich in woven bone on the buccal side, whereas that on the palatal side was rich in lamellar bone. Nasal floor membrane and a thin layer of newly formed bone, which lifted intranasally, covered the intruded molar root. Root resorption partly reached into the dentine without the formation of reparative cementum, and little or no serious pathological changes were seen in the pulp of the intruded molars. SAS effectively intruded maxillary molars, but some moderate root resorption was observed.

Animals↗
PubMed2004

Agenesis of third molar germs depends on sagittal maxillary jaw dimensions in orthodontic patients in Japan.

The aim of this study was to determine the correlation between congenitally missing third molar tooth germs and sagittal maxillomandibular jaw dimensions in orthodontic patients in Japan. The subjects were 391 patients from the orthodontic clinic of the Hokkaido University Dental Hospital who were less than 15 years of age. Assessments were made from panoramic radiographs and lateral cephalograms. The subjects were divided into a maxillary/mandibular third molar absent and an existent group. The ANB angle and the sagittal dimensions of the nasal floor (ANS-PNS), maxillary basal bone (Mx), mandibular corpus (Go-Pog), and mandibular basal bone (Mn) were measured. Logistic regression analysis was used to estimate associations between third molar agenesis and these measures. The following results were obtained: (1) The frequency of the maxillary third molar agenesis significantly increased with decreasing Mx (odds ratio = 0.559, 95% confidence interval = 0.377 - 0.829). The frequency of the mandibular third molar agenesis also increased with decreasing Mx (odds ratio = 0.532, 95% confidence interval = 0.330 - 0.856). (2) There were no significant correlations between Mn and mandibular third molar agenesis. These results suggest that agenesis of third molar germs does not depend on anteroposterior dimensions of the mandible but depends on anteroposterior dimensions of the maxilla in Japanese orthodontic patients.

Adolescent↗
PubMed2005

Ectopic eruption of the maxillary first permanent molar: characteristics and occurrence in growing children.

The purpose of this study was to determine the characteristics and occurrence of the ectopic eruption of the maxillary first permanent molar in a sample of growing Spanish children. A descriptive, observational, retrospective study was done using the radiographs of 509 consecutive patients, who were in the first phase of mixed dentition. A method was designed to evaluate the amount of pathologic resorption of the second maxillary primary molar and the impaction of the first permanent molar measured in millimeters. Statistical analysis of the studied variables was done using chi-square, analysis of variance, and Pearson correlation coefficient. The frequency of occurrence was 4.3% with no differences in both sexes. Of these, 36.4% were unilateral and 63.6% bilateral with a right:left relation of 3:1. Of the 36 ectopic molars, 69.4% self-corrected spontaneously. In such cases, the pathological resorption of the root of the second maxillary primary molar and its adverse clinical implications were persistent. The relation between self-correction and impaction was 2.27:1. The average impaction on the right side was 2.91 mm and 1.6 mm on the left side. Correlation between the magnitude of resorption and grade of impaction was not observed. Although resorption was found on grades I and II, spontaneous self-correction could occur without arch length loss. However, on grade III or more, therapeutic intervention has to be done. The benefit of early diagnosis and treatment of the maxillary first permanent molar is the prevention of the premature loss of second maxillary deciduous molar and the resulting malocclusion.

Analysis of Variance↗
PubMed2006

Maxillary molar distalization with a bone-anchored pendulum appliance.

To obtain an effective and compliance-free molar distalization without an anchorage loss, we designed the bone-anchored pendulum appliance (BAPA). The aim of this study was to evaluate the stability of the anchoring screw, distalization of the maxillary molars, and the movement of teeth anterior to maxillary first molars. The study group comprised 10 patients (mean age 13.5 +/- 1.8 years) with Class II molar relationship. A conventional pendulum appliance was modified to obtain anchorage from an intraosseous screw instead of the premolars. The screw was placed in the anterior paramedian region of the median palatal suture. Skeletal and dental changes were measured on cephalograms, and dental casts were obtained before and after distalization. A super Class I molar relationship was achieved in a mean period of 7.0 +/- 1.8 months. The maxillary first molars distalized an average of 6.4 +/- 1.3 mm in the region of the dental crown by tipping distally an average of 10.9 degrees +/- 2.8 degrees . Also, the maxillary second premolar and first premolar moved distally an average of 5.4 +/- 1.3 mm and 3.8 +/- 1.1 mm, respectively. The premolars tipped significantly distally. No anterior incisor movement was detected. The BAPA was found to be an effective, minimally invasive, and compliance-free intraoral distalization appliance for achieving both molar and premolar distalization without any anchorage loss.

Adolescent↗
PubMed2002

Effect of selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars.

The aim of this study was to assess the effect of studying selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars. A pre-test-post-test control group design was used. Given 36 patient cases, two groups of 16 general dental practitioners each were asked to assess the need for removal of asymptomatic impacted lower third molars. The cases were classified by three parameters: 'position of the third molar', 'impaction type', and 'patient age'. After studying selected literature on this subject by the intervention group, both groups were asked to assess the same cases again. Frequencies of decisions to remove the third molars were calculated. For each participant, tables were composed by crosstabulating the indication to remove a third molar with each of the three parameters. T-tests were used to test the significance of the difference between pre-test and post-test decisions. The overall number of indications to remove asymptomatic, impacted lower third molars decreased by 37% in the intervention group. In the control group, the difference between pre- and post-test was not statistically significant. It was concluded that the provision of selected literature significantly influences treatment decision making by dentists in a third molar decision task.

Adult↗
PubMed2000

Identification of root canals in molars by tuned-aperture computed tomography.

AIM: To compare the tuned-aperture computed tomography system of imaging to conventional D-speed film for their ability to identify root canals in extracted human molars. METHODOLOGY: Thirteen maxillary and six mandibular human molars were mounted in acrylic blocks to simulate clinical conditions by surrounding the teeth with a radiodense structure. The teeth were then imaged with conventional D-speed film using a standard paralleling technique, and with a modified orthopantomograph OP100 machine using a Schick no. 2 size CCD sensor as the image receptor. The source images were registered and TACT slices were generated using TACT Workbench Software. Three observers were asked to identify the number of canals in the conventional film group and the TACT image group using specific criteria. Ground truth was established by cross-sectioning the teeth at the coronal, middle, and apical thirds of the roots and directly visualizing the root canal morphology. RESULTS: TACT imaging detected 36% of 4th canals in maxillary molars and 80% of third canals in mandibular molars. Conventional film detected 0% of fourth canals in maxillary molars and 0% of third canals in mandibular molars. The differences in canal detection between the two techniques were statistically significant (Wilcoxon matched pair sign rank test, P = 0.001). CONCLUSIONS: In this study, the TACT system of digital imaging was superior to conventional film in the detection of root canals in human molars and may be useful for the detection of root canals that will probably be missed upon conventional X-ray examination.

Dental Pulp Cavity↗
PubMed2001

Root canal systems of the mandibular and maxillary first permanent molar teeth of south Asian Pakistanis.

AIM: The purpose of the present ex vivo study was to investigate variations in the root canal systems of mandibular and maxillary first permanent molar teeth of South Asian Pakistanis. METHODOLOGY: The root canal systems of a sample of 30 mandibular and 30 maxillary first permanent molar teeth extracted from South Asian Pakistanis were studied using a clearing technique. RESULTS: The mesial roots of the mandibular molar teeth typically presented with two canals (97%) of type II, IV or VI configuration. The distal roots of these teeth presented with a single canal (50%) of type I or V configuration or with two canals (50%) of type II, IV or VI. The prevalence of four root canals in two-rooted mandibular first permanent molar teeth was 47%. In maxillary molar teeth the mesial roots with a single canal (47%) were type I or type V; those with two canals (53%) were type II, IV or type VI. The distal and palatal roots that presented as a single canal (100%) were type I or type V configuration. The prevalence of four root canals in three-rooted maxillary first permanent molar teeth was 53%. CONCLUSION: It is concluded that four root canals in mandibular and maxillary first permanent molar teeth of South Asian Pakistanis is a common occurrence. The distribution of the different configurations of root canal systems in this population differed from that in Caucasian groups, suggesting that variations in root canal systems may be attributed to racial divergence.

Carbon↗
PubMed2002

Clinical and macroscopic study of maxillary molars with two palatal roots.

AIM: To report an anatomical variation in maxillary first molars. SUMMARY: A case report is presented of a maxillary first molar requiring root-canal treatment that had two palatal roots with distinct canals and foramena at the apical level. Root-canal treatment was performed using mechanical instrumentation with NiTi files. An anatomical study on two extracted maxillary second molars with the same variation revealed their internal structure. This case demonstrates an uncommon anatomical condition and supplements previous reports of such cases affecting maxillary molars. KEY LEARNING POINTS: Clinicians should be aware of uncommon anatomical variations in maxillary molars. The majority of maxillary first molars have three roots and four canals. Maxillary molars may have two canals in the palatal root.

Adult↗
PubMed2004

Periodontal healing after mandibular third molar surgery--A comparison of distolingual alveolectomy and tooth division techniques.

The purpose of this study was to compare the periodontal healing of mandibular second molars after the removal of impacted mandibular third molars using distolingual alveolectomy and tooth division techniques. A total of 120 consecutive healthy patients who presented with bilaterally impacted mandibular third molars were included in this study. The same operator removed the impacted third molars on both sides in all patients. The third molar on one side was removed by distolingual alveolectomy using a chisel, whereas the contralateral tooth was removed by the tooth division technique using burs. Attachment level, periodontal pocket depth and bone healing distal to the mandibular second molars were assessed at 7 days, 3 months and 6 months after surgery. The results showed better periodontal healing and bone healing when distolingual alveolectomy was employed, especially in the removal of deeply impacted mandibular third molars.

Adolescent↗
PubMed2001

Cephalometric comparison of maxillary second molar extraction and nonextraction treatments in patients with Class II malocclusions.

This retrospective cephalometric study compared the nature of the skeletodental correction of maxillary second-molar extraction and nonextraction treatments in correcting Class II malocclusions. The sample comprised 50 Class II, deep-bite, low-angle adolescents; half were treated with maxillary second-molar extraction and half were treated without extraction. Pretreatment and posttreatment lateral cephalograms were analyzed. Analysis relied primarily on the method of Lysle Johnston that evaluates sagittal changes in the teeth and supporting bones relative to the functional occlusal plane. All 18 cephalometric variables examined were statistically equivalent between the 2 groups at the start of treatment. In contrast, several skeletodental treatment changes differed significantly. The maxillary second-molar extraction group exhibited distal movement of the maxillary first molar (1.2 mm vs 0.0 mm), and there was greater flaring of the mandibular incisors in the nonextraction group (9.1 degrees vs 3.5 degrees ). The upper incisor root was torqued lingually in both groups, but there was more anterior crown movement in the nonextraction group (2.0 mm vs 0.0 mm). Also, the extraction group finished active treatment 7 months sooner on average. Sagittal molar correction in the maxillary second-molar group was a result of distalizing in the maxillary arch, whereas anchorage was expended in the mandibular arch to correct the malocclusion in the nonextraction group. In properly selected Class II malocclusions, maxillary second-molar extraction is a viable alternative treatment choice.

Adolescent↗
PubMed2002

Incidence of chronic neuropathic pain subsequent to surgical removal of impacted third molars.

To determine the incidence of atypical odontalgia/chronic neuropathic pain subsequent to surgical removal of impacted third molars, a telephone survey and a clinical investigation were carried out. Patients operated on for impacted mandibular third molars during 1994 96 in the Oral Surgery Clinic. School of Dentistry, University of Bergen, Bergen, Norway, were contacted by telephone. Answers were obtained from 1035 (71%) out of a total of 1458 operated patients. Median observation time was 5 years 9 months, ranging from 4 years 5 months to 6 years 9 months. All except 23 (2.2%) patients stated that they had no long-term symptoms or problems from the surgical site, jaw, or face after the third molar removal. These 23 patients were all examined clinically and radiologically, and symptoms and findings were evaluated. Seventeen patients had TMJ dysfunction: primarily pain of muscular and joint origin. Three patients had a periodontal problem associated with the adjacent second molar, with deep bony pockets and recurrent periodontal infection while two had chronic pulpitis of a second molar. One patient reported a temporary maxillary pain after removal of an ipsilateral mandibular third molar. None of the patients met the criteria for a diagnosis of atypical odontalgia/neuropathic pain. A 95% confidence interval of 0-0.38% of incidence rate of postoperative neuropathic pain was calculated. It is concluded that atypical odontalgia/ chronic neuropathic pain subsequent to surgical third molar removal is rare.

Adult↗
PubMed2003

Radiographic findings on 3rd molars removed in 20-year-old men.

In this study we assess radiographic findings characteristic of mandibular 3rd molars that had required either routine or surgical extraction. X-ray findings relating to acute pericoronitis were also examined. The material was collected by investigating patient records and rotational panoramic radiographs of 20-year-old Finnish male conscripts (n = 738) treated during military service because of 3rd-molar-related problems. The follicle around the crown of mandibular 3rd molars with acute pericoronitis was enlarged in 19% of cases and in 13% of chronic symptom-free pericoronitis cases (not statistically significant difference). Mandibular 3rd molars extracted surgically were more often mesially inclined than those extracted routinely (61% vs. 23%; P < 0.001), partially or totally intrabony impacted (92% vs. 66%; P < 0.001) and deep situated (on average 4.2 mm vs. 2.5 mm under the occlusal plane). Surgical extraction was also associated with the roots completely developed [92% vs. 84% of the teeth routinely extracted, odds ratio (OR) 2.6, 95% confidence interval (CI) 1.2-5.5] and with the absence of radiographic pericoronitis [around 27% vs. 39% of the teeth routinely extracted (OR 0.5, 95% CI 0.3-0.8)]. In 86% of cases the space between 2nd molar and ramus of the mandible was narrower than the 3rd molar extracted surgically, whereas this was 62% in routine extraction cases (P < 0.001). We conclude that there are some typical 3rd-molar findings in rotational panoramic radiographs that show a need for surgical extraction.

Adult↗