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At least 793 records · Page 44Linked to original sources
PubMed2006

Efficacy of methylprednisolone in controlling complications after impacted lower third molar surgical extraction.

INTRODUCTION: Impacted third molar extraction causes considerable swelling in the days immediately following surgery. The aim of the present investigation was to evaluate the efficacy of methylprednisolone as a single 40-mg intramuscular dose in controlling the complications of impacted lower third molar surgical removal. MATERIALS AND METHODS: Thirty-five patients were evaluated within the framework of a consecutive sampling and double-blind study with intrasubject measurements. Extraction comprised ostectomy with tooth sectioning of both lower third molars under local anesthesia. The study group received 40 mg of methylprednisolone injected into the gluteal region, while the controls received no such medication. In each individual one molar was randomly assigned to the study group and the other to the control series - with extraction of the two teeth being spaced 1 month apart. Evaluations were made of postoperative pain, trismus and swelling, and measurements were obtained for oral aperture and various distances (tragus-lip commissure, gonion-lip commissure and gonion-external canthus of the eye) before surgery and 2-7 days after extraction. Statistical correlations were made based on the Student t-test for the comparison of means of related samples. RESULTS: A statistically and clinically significant association was observed 2 days after surgery between methylprednisolone administration and increased oral aperture and diminished facial swelling. Likewise, less pain was recorded in the study group 6 h after surgery. CONCLUSION: The results confirm the efficacy of methylprednisolone in providing a more comfortable postoperative course after surgical extraction of impacted lower third molars.

Adult↗
PubMed2004

High-resolution dental magnetic resonance imaging of inferior alveolar nerve responses to the extraction of third molars.

The objective of this study was to assess whether signal changes can be detected in the neurovascular bundle of the mandibular canal after the extraction of a third molar. We retrospectively analyzed MRI scans of 30 test subjects with healthy mandibles and 41 patients who had had a wisdom tooth extracted. Signal intensities were measured at particular sites in the neurovascular bundle, which were defined as regions of interest (ROI) in the sagittal T1-weighted images before and after intravenous administration of a paramagnetic contrast agent. On the basis of the signal intensity increases that were measured after contrast agent administration, we compared the signal increases obtained for the patients who had received surgical treatment with the results obtained for the population of test subjects with unremarkable mandibles ( t-test, P<0.05). Compared with the healthy test subjects, patients who had received surgical treatment showed significantly higher signal intensity increases at two measurement sites, i.e., the second molar and the second premolar ( P<0.05). We found no significant differences when the measurements were performed at the first molar ( P=0.06), the third molar ( P=0.47) and in the area of the ascending mandibular ramus ( P=0.79). Compared with a population of healthy test subjects, patients who had their third molars surgically removed show higher signal intensity increases in the neurovascular bundle after intravenous contrast agent administration. The underlying cause may be the higher blood flow in the arteries and veins and the perineural plexus, which may give evidence of the pathophysiological mechanism of nerve damage in the narrow canal as a result of osteotomy.

Adolescent↗
PubMed1997

Development of interglobular dentine in rat molars and its relation to maturation of enamel.

The development of interglobular dentine in the first upper and lower molars of Wistar rats aged 3, 7, 14, 21, 42 days was examined histochemically using a lectin, succinyl wheat germ agglutinin (sWGA), which is specific for N-acetyl-D-glucosamine. sWGA stained the interglobular dentine, predentin and Golgi area of odontoblasts. Interglobular dentine was not formed in the first molars of 3-day rats, but appeared in those of 7-day rats near the enamel-free area. In 14-day rats, interglobular dentine was present in most areas of the coronal dentine except the cervical area. At the interface between dentine and predentin, numerous sWGA-negative calcospherites were seen, suggesting that the interglobular dentine is formed actively there. In 21-day rats, the interlobular dentine was more numerous than in 14-day rats. Interglobular dentine was present in the cervical root dentine as well as in the coronal dentine, including the cervical area. The distribution of interglobular dentine in 42-day rats was similar to that in 21-day rats, but fluorescence of sWGA binding was less intense in the former. Because the development of interglobular dentine appeared to be time and position specific its relation to the stages of ameloblasts was analysed. Thin enamel matrix was formed at cusps in molars of 3-day rats and thickness of enamel matrix increased in 7-day rats. In these teeth, the ameloblasts were at the differentiating or secretory stage. The Golgi area and Tomes' processes of the secretory ameloblasts, the cells of intermediate layer and the enamel matrix were weakly positive with sWGA. The epithelial cells at the enamel-free area were also stained with sWGA. In 14-day rats, most of the ameloblasts in the first maxillary molars were at the maturative stage except in the cervical area, where the ameloblasts were at the transitional stage. sWGA stained the distal border and the Golgi area of the maturative ameloblasts as well as the cells of the papillary layer. The distal border of the maturative ameloblasts appeared either thick or thin, suggesting a ruffle-end and smooth-end of the cells. Ameloblasts were absent in the first molars of 21-day rats and the cervical part of the enamel was covered with the stratified epithelium like that of 42-day rats. The present study has demonstrated that interglobular dentine contains sWGA-binding glycoconjugates and the formation of the interglobular dentine is largely associated with the enamel maturation. These results suggest that matrix-to-cell interaction is important for the development of interglobular dentine.

Acetylglucosamine↗
PubMed2002

Patterns of third molar impaction in a group of volunteers in Turkey.

The aim of this study was to investigate the different variables in mesio-vertically positioned impacted or erupted third molars in a group of volunteers in Turkey to determine the angular changes and levels of eruption radiographically using standardised panoramic radiographs. There were 213 volunteers with impacted and erupted third molars included in this study, most of whom were dental students. Standardised panoramic radiographs were taken from all the volunteers. The radiographic parameters included angulation of tooth, level of eruption, development of root, mesiodistal crown width, retromolar space, and gonial angle. Statistical analysis was done using the t-test for independent groups. It was found that the mesiodistal angulation of third molars was significantly greater while the retromolar space of third molars was significantly smaller in the impacted group (P<0.05). There was also a significant difference in retromolar space/third molar crown width ratio (P<0.05).

Adolescent↗
PubMed2001

Incidence of deep fascial space infection after surgical removal of the mandibular third molars.

Nine hundred and ninety-three patients who underwent surgical removal of the mandibular third molars with oral antibiotic prophylaxis were examined to determine the incidence of postoperative deep fascial space infection and its background factors. Postoperative deep fascial space infection was observed in 8 of the patients (0.8%; 4 males and 4 females), and submandibular spaces were involved in all infected patients. Only 1 of these 8 patients was an immune compromised host. Patients aged 30 years or more had a significantly higher incidence of deep fascial space infection than those aged under 30. Five patients had partial bony impactions and 3 had complete bony impactions. However, the incidence of infection according to the molar positions was not significantly different between partial bony impaction and complete bony impaction. The 8 patients had not had pericoronitis preoperatively. The clinical courses of all were favorable after antibiotics were administered intravenously. In conclusion, the incidence of deep fascial space infection after removal of the mandibular third molars was low, at 0.8%. However, it may be desirable to remove the molars, if applicable, at a younger age because of the higher incidence of infection in patients aged over 30. The results of this study also offer information that will be useful as a basis for obtaining informed consent from patients whose mandibular third molars are to be removed.

Adolescent↗
PubMed1981

Reliability and validity of lower third molar space-assessment techniques.

Present techniques for predicting eruption or impaction of lower third molars are based on measurements of the space between the second molar and the ramus. This study was designed to investigate the reliability and validity of radiographic techniques often used for assessing this space. Rotational tomograms (O.P.G.s) yielded the best estimates of the Space Width Ratio (found by dividing the space available by the mesiodistal width of the lower third molar) as measured directly on dried skulls. Estimates for lateral cephalograms were unreliable. The use of Xi point to lower second molar for assessing the space for lower third molars is not supported.

Adult↗
PubMed1982

Extraction of third molars in cases of anticipated crowding in the lower jaw.

The purpose of this study was to ascertain whether the lower third molar, in combination with other variables such as facial morphology and space conditions, can contribute to the occurrence or aggravation of crowding. The subjects consisted of twenty-three boys and twenty-nine girls with impacted third molars on both sides of the mandible. The impacted molar on one side was removed, while the other, nonextracted side was used as a control. Average age at the time of operation was 15.5 years (range, 13 to 19). Close to the operation and annually for at least 3 years afterward, study casts and cephalograms (lateral, frontal, and oblique) were taken. The findings indicated that (1) despite analyses of many variables, this study has not been able to predict which patients should react favorably or unfavorably to removal of the third lower molars in cases of anticipated crowding; (2) in cases with severe crowding removal of the molars could be recommended; (3) correct proximal contacts seem to be of importance in keeping the space that is achieved by extraction, while incorrect ones may spoil it.

Adolescent↗
PubMed1987

A scanning electron-microscopic, stereo-pair study of methacrylate corrosion casts of the mouse palatal and molar periodontal microvasculature.

Microvascular beds of the palate, gingiva and periodontal ligament had interconnected but distinct, regional patterns. The palatal vasculature reflected mucosal-crest morphology: crestal capillary vessels of the rugae anastomosed with sagitally-orientated rows of 8 microns capillary loops, and, in the inter-rugal troughs, these formed a flat plexus overlying collecting veins more than 100 microns in diameter. Maxillary and mandibular molar ligaments had similar microvascular patterns. The molar gingiva had a circular, outer capillary and inner venous system linked by radial anastomoses. The outer (7 microns) capillaries enclosed the three molars in a continuous horizontal loop coursing beneath the crestal epithelium; the inner (10-15 microns) venous vessels encircled each molar just below the epithelial attachment. Glomerulus-like vascular formations, with an arterial and venous stalk, were associated with the inner circular system and extended toward the crevicular epithelium. Axially aligned, post-capillary, periodontal-ligament vessels (21 microns) anastomosed with the inner circular system, forming different patterns in the occlusal, middle and apical thirds. The apical pattern comprised an enveloping plexus of anastomosing venous vessels supplied by arterio-venous shunts; similar shunts were present throughout the ligament. The microvascular bed of the mandibular inter-radicular ligament was characterized by the presence of a large venous ampulla measuring 60 by 200 microns. Some regions of the ligament microvasculature drained via the medullary vessels into 50 microns-diameter venules located interdentally deep to the molar apices. Volumetrically, the ligament microvascular bed was predominantly of post-capillary venules, and morphologically, a paired arterial and venous system was not demonstrated.

Animals↗
PubMed1990

Immunolocalization of transforming growth factor beta 1 and epidermal growth factor receptor epitopes in mouse incisors and molars with a demonstration of in vitro production of transforming activity.

Day-14 lower incisors and day-18 first lower molars of mouse embryos produced in vitro transforming activities for non-confluent NRK cells co-cultured in agar, and mitogenic activities for exponentially growing NRK and BHK cells. The patterns of distribution of TGF beta 1 and EGF receptor, both known to regulate cell proliferation, differentiation and transformation in vitro and suspected to play important roles in developmental processes, were studied during mouse odontogenesis by means of indirect immunofluorescence on fixed or frozen fixed sections. TGF beta 1 epitopes were detected in the stellate reticulum of day-13 to day-16 incisors and of molars from day-17 onwards. Dental mesenchyme of day-14 incisors and postnatal molars, and peridental mesenchyme of bud and cap stage molars and incisors were also stained by TGF beta 1 antibodies. EGF receptor was localized in the enamel organs of incisors and molars; the inner dental epithelium and later the outer dental epithelium rapidly became negative while the stellate reticulum remained stained. Incisor apical mesenchyme showed an intense reaction with EGF receptor antibodies after birth.

Animals↗
PubMed1991

Immunohistochemical analysis of pulpal innervation in developing rat molars.

The beginning of pulpal innervation was examined in these developing teeth. Mandibular first molars removed from newborn to 7-day-old rats were cryosectioned and nerve fibres were localized by the peroxidase-antiperoxidase technique using a neuropeptide-specific (200 kDa) antibody. Some pulps from 5- and 7-day-old rats were also examined by conventional electron microscopy. In newborn to 4-day-old rats, molars in the initial stages of the dentine deposition were innervated in the follicles but not in the pulps. In molars from 5-day-old rats, nerve fibres were found in the pulps of 11 out of 16 samples. The fibres were mainly located along the blood vessels in the basal part of the pulp, with some arborizations. In rats of 6 and 7 days old, nerve fibres were found in all the pulps examined. These had gradually extended deep into the cuspal area and were increasingly arborized with increasing age. Nerve fibres were also found along the basal laminae of blood vessels in some dental pulps from 5-day-old rats when examined by electron microscopy. At 7 days, nerve fibres were composed of bundles of axons, some of which were covered with Schwann cell processes and basal laminae. These observations indicate that the innervation of rat molar dental pulps begins after the start of the deposition of enamel, in animals of around 5 days of age, which is at the same stage as in mouse molars, as others have shown by a silver-staining method.

Aging↗
PubMed1993

The effect of velocity of loading on the biomechanical responses of the periodontal ligament in transverse sections of the rat molar in vitro.

Stress-strain relations of this ligament in transverse sections of the mandibular first molar were examined over a wide range of velocities of loading from 1 to 10(4) mm/24 h. With increasing velocities, the maximum shear stress, tangent modulus and failure strain-energy density increased but the maximum shear strain decreased. The mechanical responses at the highest velocity for the molar ligament were compared with those previously found for the incisor ligament. Mechanical strength, stiffness and toughness were greater for the molar than for the incisor ligament; the molar ligament therefore has more extensible fibres or a different fibre arrangement. Comparison of the mechanical responses at the slowest velocity suggests that, though the stress level was greatly reduced (presumably because of stress relaxation), the fibre components of the molar ligament still reacted at this velocity. It is also suggested that the differences in the ratios of the mechanical measures in 10(4)-1 mm/24 h between the two types of teeth are due partly to their different periodontal fibre architectures.

Alveolar Process↗
PubMed1994

The effects of anti-nerve growth factor on retrograde labelling of superior cervical ganglion neurones projecting to the molar pulp in the rat.

The aims were to demonstrate sympathetic ganglion neurones projecting to the rat molar pulp and to determine whether deprivation of nerve growth factor (NGF) in neonatal rats eliminates this source of pulpal innervation. Newborn Sprague-Dawley rats were given subcutaneous injections of rabbit anti-mouse-NGF serum for 1 month. Control animals included litter mates treated with preimmune serum and untreated, age-matched rats. AT 4 months of age, Fluoro-gold (FG) was applied to the pulp chamber of the right first maxillary molar. One week later, the animals were perfusion fixed, and the superior cervical ganglia (SCG) were removed, embedded in paraffin, and serially sectioned at 10 microns. FG-labelled cells were detected by epifluorescence microscopy with a u.v. filter set. Control animals had 5-10 FG-labelled neurones widely distributed throughout the SCG ipsilateral to the injection site and no labelled cells in the contralateral SCG. NGF-deprived animals had either no FG-labelled cells or a single labelled cell in the ipsilateral SCG. These results indicate that, in rats, (1) the number of SCG neurones projecting to the molar pulp is rather low, (2) SCG neurones that innervate the dental pulp of the maxillary molar pulp are dispersed throughout the ganglion, (3) the projection from SCG to the molar is exclusively ipsilateral, and (4) neonatal NGF deprivation induces a permanent, almost total, loss of sympathetic neurones projecting to the dental pulp.

Animals↗
PubMed1975

Modification of stresses in alveolar bone induced by a tilted molar.

Stresses induced in the supporting bone by a tilted molar tooth under load have been investigated by both the photoelastic and the finite element model systems. The following conclusions were reached. 1. Altering the angle of the load applied to the unsupported molar from 0 (axial) to 30 degrees resulted in a fourfold increase in compressive stress in the supporting bone mesial to the tooth. 2. Increasing the load from 30 to 90 pounds while maintaining a 30 degree angle of application resulted in a linear increase in the shear stress on the supporting bone mesial to the tooth. 3. Following the placement of a fixed partial denture, the induced stress at a point on the mesial aspect of the molar tooth, subjected to a 60 pound load at 30 degrees to the long axis, was reduced from 241 to 43 p.s.i. 4. The introduction of a fixed partial denture resulted in a decrease in the compressive stress in the bone adjacent to the apex of the mesial root of the molar from 481 to 174 p.s.i. 5. A distributed 120 pound load applied over the length of the fixed partial denture compared against individual tooth loadings of 60 pounds revealed that placement of the fixed partial denture favored the tilted molar at the expense of the premolar.

Alveolar Process↗
PubMed1980

Periodontal conditions in patients after molar uprighting.

Fifteen patients who had mandibular molars uprighted unilaterally and seven patients who had mandibular molars uprighted bilaterally were examined an average of 3 1/2 years after treatment had been completed. The investigation focused on differences in clinical observations between the treated teeth and the controls on the contralateral side at the time of the recall examination. Pretreatment radiographs provided longitudinal observations. After elimination of significant but unrelated factors, including surgical pocket elimination and the presence or absence of subgingival margins, the following appeared. Changes in alveolar bone height mesial to the uprighted molars were not different from changes mesial to control teeth. Gingival inflammation scores around uprighted molars were not different from those around control teeth. Pockets mesial to uprighted molars were shallower than those mesial to control teeth. Observations on pocket depth distal to the teeth considered were inconclusive.

Adult↗
PubMed1986

A scanning electron microscopic investigation of accessory foramina in the furcation and pulp chamber floor of molar teeth.

Observations of the pulp chamber floor and furcation surface of human maxillary and mandibular first and second molars were made with the scanning electron microscopic to determine the incidence, size, and location of patent accessory foramina. Accessory foramina on both the pulp chamber floor and the furcation surface were found in 36% of maxillary first molars, 12% of maxillary second molars, 32% of mandibular first molars, and 24% of mandibular second molars. Mandibular teeth had a higher incidence (56%) of foramina involving both the pulp chamber floor and furcation surface than did the maxillary teeth (48%).

Dental Pulp Cavity↗
PubMed1987

Mandibular third molar development after mantle radiation in long-term survivors of childhood Hodgkin's disease.

Sequential panoramic radiographs were assessed for mandibular third molar development in 47 long-term survivors of childhood Hodgkin's disease after treatment with 37 Gy mantle field radiation. To make a comparison, panoramic radiographs of 149 healthy, nonirradiated children were reviewed for the presence of mandibular third molars. In children between the ages of 7 and 12 years, bilateral agenesis of mandibular third molars was more frequent in patients who had been treated with mantle radiation than in nonirradiated patients. Unilateral agenesis, crown hypoplasia, and root growth impairment of mandibular third molars were also found. Similar, apparent, radiation-induced developmental anomalies were noted in maxillary third molars of the irradiated patients.

Abnormalities, Radiation-Induced↗
PubMed1991

Clinical follow-up study of third molar eruption from ages 20 to 26 years.

The development of 412 upper and lower third molars was clinically followed up for 6 years in 120 students, starting at the age of 20 years. Clinical and radiographic examinations carried out at baseline and 6 years later showed that during the follow-up period almost half the third molars originally recorded as partially erupted had erupted. When the lower third molars were initially invisible, only 9% of them had erupted by age 26 years whereas 29% remained invisible. When third molars had been already erupted at baseline, only a few were extracted during the 6-year follow-up period. It was concluded that a certain proportion of third molars erupt relatively late, and therefore the need for surgical interventions may decrease with age during early adulthood.

Adult↗
PubMed1993

Side effects and complications associated with third molar surgery.

A retrospective analysis of complications and side effects associated with surgery for 1000 mandibular and 500 maxillary impacted third molars was performed. The analysis included 614 patients with impacted mandibular third molars and 274 with impacted maxillary third molars who were treated in a 5-year timeframe from 1987 to 1992. The incidence of intraoperative complications and side effects of mandibular third molar surgery was 1.1% and 4% for maxillary third molar surgery whereas postoperative complications were 4.3% and 1.2%, respectively.

Adolescent↗