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Management of impacted third molars among Nigerian dentists.

Seventy-five Nigerian dentists were interviewed on their approach to the management of impacted third molars. The mean age of the dentists was 34.8 years, with a male/female ratio of 3.4:1. Most of the female dentists were found in the training institutions (p = 0.005). More than half of the dentists (58.7%) practiced in institutions with dental schools (training institutions), majority preferred the buccal approach (92%), and all the dentists (100%) preferred third molar disimpaction under local analgesia. Most dentists (88%) prescribe antibiotics following third molar surgery. Fifty dentists (66.7%) routinely reviewed all patients postoperatively while 12 dentists (16%) were of the opinion that all impacted third molars should be extracted. Only 21 dentists (28%) were aware of any protocol on the management of impacted teeth. More dentists in the training institutions performed third molar surgery less frequently than dentists in other hospitals (p = 0.07) who tend to employ chisels/mallet for bone removal (p = 0.0004). The need for continuing education and the formulation of guidelines in order to assist dentists to make informed decisions is emphasised. This will help conserve scarce resources and enhance the operation of the newly introduced National Health Insurance Scheme.

Adult↗

Effects of tube drain with primary closure technique on postoperative trismus and swelling after removal of fully impacted mandibular third molars.

OBJECTIVE: Surgical removal of impacted mandibular third molars with primary wound closure may result in postoperative edema, facial swelling, pain, and restriction of mouth opening. The type of closure may be a cause of these complications. The aim of this study was to compare the effects of placement of a surgical tube drain before primary closure with the effects of primary closure alone after removal of fully impacted mandibular third molars. METHOD AND MATERIALS: The study group included 13 patients aged 15 to 39 years with bilateral fully impacted mandibular third molars. The insertion of a small surgical tube drain before primary closure (drain group) was compared to a simple primary closure procedure (no drain group) after removal of the impacted third molars in a randomized crossover design. The duration of the operation was recorded. Patients were evaluated 1, 2, 3, and 7 days postoperatively for facial swelling and trismus. RESULTS: The facial swelling experienced by the drain group was significantly less than that experienced by the no drain group. The degree of trismus was greater in the no drain group than in the drain group, but the difference was not statistically significant. CONCLUSION: Use of a surgical drain, especially after removal of fully impacted third molars, will reduce postoperative facial swelling.

Adolescent↗

Accessibility of an ultrasonic furcation tip to furcation areas of mandibular first and second molars.

The purpose of this study was to compare an ultrasonic furcation tip with an ultrasonic conventional tip and a hand scaler on accessibility to furcation areas of mandibular first and second molars. The study was conducted on 360 artificial molars that were replicated from 30 mandibular first molars and 30 second molars with silicone impression material and resin. The furcation areas of each molar were coated with red nail colour for artificial calculus. The root areas from the cement-enamel junction apically were covered with silicone rubber simulating gingival tissue. Then the models were instrumented on the buccal or lingual aspects by an experienced operator with each of the following instruments: an ultrasonic furcation tip, an ultrasonic conventional tip and a hand scaler. After instrumentation the percentage of the furcation area with residual artificial calculus was assessed using a computerised imaging system. Results showed that when the horizontal pocket depth was less than 2mm, all three instruments showed good accessibility. When the horizontal pocket depth was more than 2mm, the ultrasonic conventional tip and the hand scaler showed less removal of artificial calculus than the ultrasonic furcation tip (P < 0.01). Efficiency of the ultrasonic furcation tip was fairly satisfactory for the horizontal pocket up to the ridge of the furcation roof.

Dental Calculus↗

[Analysis of stress in the periodontal tissue of the maxillary first molar on distal movement by finite element method].

OBJECTIVE: The aim of this study was to analyse the stress distribution in the periodontium of the maxillary first molar and to search optimal loads pattern when distal movement to provide biomechanical basis for the clinical practice. METHODS: By spiral CT scanning, a three-dimensional finite element model of the maxillary first molar was established, and then four different load patterns were added to the molar to obtain the optimal load partern for molar bodily distal movement. RESULTS: Different loads lead to different stress distributions when distal movement. CONCLUSION: A distalizing force combined with a countertipping moment (Mt/F = 10) and a counterrotation moment(Mr/F = 6) can lead to a lower and uniform stress on the distal side of the periodontal ligament, it implys a tendency of translation of the maxillary first molar.

Biomechanical Phenomena↗

Migrating third molar: a report of a case.

Pathologic migration is an abnormal change in the position of a tooth within the dental arch. There are many etiologic factors associated with this phenomenon, but the exact cause is often difficult to diagnose. The following is a report of a 42-year-old man exhibiting a unique form of bilateral migration of his mandibular third molars. He was asymptomatic and unaware of this occurrence. The morbidity to remove these teeth was deemed too great to justify extraction. Biopsy of the overlying tissue associated with a left-impacted third molar revealed no significant pathologic process other than inflammation and some hyperplasia within the dental follicle. Histologic-radiographic correlation was inconclusive in determining whether epithelium from pericoronal soft tissue involving the right third molar was from a hyperplastic dental follicle or a small dentigerous cyst. It is speculated that the ultimate cause of the migration of the third molars was severe, aggressive periodontal disease of the adjacent molars.

Adult↗

[Expression of homeobox gene Msx-1, Msx-2 and Dlx-2 during murine mandibular first molar development].

OBJECTIVE: To observe the expression of homeobox gene Msx-1, Msx-2 and Dlx-2 during murine mandibular first molar development. METHODS: The murine heads or mandibles on embryonic days 11-18 (E11-18) and postnatal day 1-3 (P1-3) were removed, fixed and embedded, 5 micro m serial sections were cut in the coronal plane. Msx-1, Msx-2 and Dlx-2 RNA probes were synthesized by in vitro transcription and labeled with digoxigenin. Msx-1, Msx-2 and Dlx-2 mRNA expression was observed after in situ hybridization. RESULTS: During molar development Msx-1 transcripts appeared only in mesenchymal cells, not in epithelial cells. Msx-2 and Dlx-2 both expressed in the epithelial and mesenchymal cells. At the initiation stage of the molar development Msx-2 and Dlx-2 had similar expression. At the bud stage (E13-14) Msx-2 mRNA signaling was intensive in the enamel organ and slight in the dental mesenchyme; Dlx-2 signaling was stronger in the dental papilla. At cap stage (E15-16) Msx-2 showed prominent mRNA signaling in enamel knot and Dlx-2 was maximal in the dental papilla. At the late bell stage (P2-3) Msx-2 transcripts were observed in odontoblasts but not labeled in ameloblasts, and Dlx-2 transcripts appeared in ameloblasts but no labeling was seen in odontoblasts. CONCLUSIONS: Msx-1, Msx-2 and Dlx-2 are expressed in various patterns during murine mandibular first molar development, suggesting they possibly play a role in the interaction between the epithelium and mesenchyme during the molar development.

Animals↗

Timing and effect of fissure sealants on permanent molars: a study in Finland and Sweden.

Fissure sealants are frequently used in the Nordic countries for the prevention of caries in children. The aim here was to analyse their use and effect on dental health in children and adolescents in Finland and Sweden. A retrospective longitudinal population-based study was performed in northern Finland and Sweden, where different strategies have been adopted for sealing teeth. The timing of sealant and restoration placements up to 18 years was studied in representative samples of subjects born in the early 1980s in Kemi, Oulu, Raahe and Tornio in Finland (n = 908) and compared with a random sample of subjects from Norrbotten, Sweden (n = 634). A sensitive survival analysis method was applied to all the permanent molars separately (Virtanen et al. 1996). About 80-90% of molars had been sealed in the Finnish subjects, and approximately 30% in the Swedish cases, employing selective criteria. The filling increments were statistically significantly higher in Sweden than in Finland, although the differences were not of the same magnitude as the reduction in sealants. More than 30% of first molars and 50% of second molars had not been treated, i.e. were without sealants or fillings, by the end of the follow-up in Sweden, compared with 10% and 20%, respectively, in Finland. Fissure sealants were effective in preventing caries in molars in children and adolescents, and the use of selective criteria for targeting this treatment can yield savings in effort and costs in a low caries situation, although more research is needed to find the optimum cost-effective strategy.

Adolescent↗

Effects of fluoride on secretory and postsecretory phases of enamel formation in sheep molars.

Effect of fluoride was assessed on molars during and after mineralization. Two groups of 7 sheep each were dosed orally with 3.5 mg of fluoride/kg of body weight daily for 4 months (from 5 to 9 months after birth). Sheep of the first group were slaughtered immediately after fluoride administration; those of the second group were slaughtered 4 months later at the age of 13 months. Three control groups of 7 sheep each were slaughtered at 5 months (to determine the state of the teeth at the beginning of fluoride administration), and at 9 and 13 months. During fluoride administration, plasma fluoride concentration rapidly increased to about 0.50 microgram/ml; after fluoride administration, it stabilized at 0.20 microgram/ml in treated sheep, whereas controls had concentration of 0.10 micrograms/ml (P less than 0.01). Parts of the molars that were in the process of mineralization during fluoride administration (mainly second molars) had thinning enamel, with pits, mainly close to the apex, marked decrease in hardness throughout the layer (less than 100 Vickers U, compared with 240 Vickers U), and fluoride accumulation twice as high as that in controls (1,000 to 2,500 mg/kg [dry weight]). Fluoride accumulation was higher in dentine (2,700 to 4,200 mg/kg), but hardness was less affected. On parts of the molars that were already mineralized (mostly, the first molar), changes in the appearance of enamel and cementum, decreased hardness (less important than in teeth during mineralization) affecting outer enamel more than inner enamel, high fluoride concentration (4,000 to 5,500 mg/kg [dry weight]) in outer enamel extending over 200 microns were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Ameloblasts↗

Effect of dexamethasone and dipyrone on lingual and inferior alveolar nerve hypersensitivity following third molar extractions: preliminary report.

AIMS: To study the effect of dexamethazone and dipyrone on sensory changes in the innervation territories of the inferior alveolar, infraorbital, and lingual nerves caused by third molar extractions. METHODS: Fourteen patients (8 men and 6 women) were divided randomly into 2 groups. The first group received dipyrone preoperatively, while the second group received dipyrone and dexamethazone preoperatively. All patients in the study received a prophylactic preoperative dose of amoxicillin (500 mg) as well as dipyrone postoperatively. In all patients, a single mandibular third molar was removed, while in 2 patients the contralateral third molar was removed at a subsequent time. Electrical detection thresholds were assessed in the inferior alveolar, lingual, and infraorbital nerve regions prior to surgery and 2 and 8 days following surgery. The level of perioperative pain, difficulty of extraction, and distance of molar root apices from the inferior alveolar nerve canal were also assessed. RESULTS: Patients who received only dipyrone had significantly reduced lingual and inferior alveolar nerve electrical detection thresholds 2 days after surgery, which returned to nearly baseline values by the eighth day postoperatively. In patients who received dexamethasone, no significant reduction in the electrical detection threshold was found. CONCLUSION: Preoperative treatment with dexamethasone and dipyrone but not dipyrone alone prevents sensory hypersensitivity following third molar extraction.

Anti-Inflammatory Agents↗

[Nerve injury during mandibular third molar surgery. The importance of preoperative diagnosis and surgical skill].

A 26-year-old woman was referred by a dentist to an oral and maxillofacial surgeon after an unsuccessful attempt to remove a mandibular third molar. A panoramic radiograph showed the remaining root of the third molar and the patient suffered from insensitivity of the lower lip. The root of the third molar was removed surgically. The sensitivity of the lip recovered completely within three months. Injury of the inferior alveolar nerve and the lingual nerve is a serious complication after mandibular third molar removal. The inferior alveolar nerve is at risk for injury if the third molar root is intimately connected with the mandibular canal. Refraining from preoperative clinical and radiographic diagnostics is malpraxis. Surgical skill is a prerequisite to reduce the risk of nerve injury.

Adult↗

Mandibular third molar autotransplantation--literature review with clinical cases.

Autotransplantation of mandibular third molars in a precocious phase of development is indicated when a substitute for adjacent compromised or missing molars is needed, and when mesial movements of the posterior teeth, the resultant loss of space, and overeruption of opposing teeth and consequent changes in the occlusion must be avoided. Provided that the apices of the mandibular third molar are immature, the immediate replacement of a lost or compromised tooth usually ensures a good outcome. Transplantation of third molars helps to maintain alveolar bone and enables endosseous implantation without requiring bone regeneration. We present examples of transplantation of mandibular third molars and review the factors that affect the success or failure of this procedure, such as atraumatic extraction and adequate immobilization of the transplanted tooth and root development after transplantation. Sex or age seem to have no effect on the final outcome.

Adolescent↗

Failure of tooth eruption involving a mandibular primary first molar: a case report.

PURPOSE: Primary failure of tooth eruption involving primary teeth is unusual. The purpose of this report was to describe uneruption of a single mandibular primary first molar and the treatment outcome following limited orthodontic care. METHODS: A 5-year, 3-month-old boy was referred to the authors' clinic for treatment of an unerupted primary first molar, 3 months after fenestration by an oral surgeon. Orthodontic traction was performed on the affected molar in the authors' clinic. The affected mandibular primary first molar was fully erupted and in occlusion 16 months after the first fenestration. RESULTS: The histopathological diagnosis of the overlying tissue was pericoronal myxofibrous hyperplasia (PMH) without any calcified obstacles. CONCLUSIONS: Of the 26 primary tooth eruption failure cases treated in the authors' clinic between 1979 and 2003, the present case was the only example of a primary first molar.

Child, Preschool↗

The relationship of the inferior dental canal to the roots of impacted mandibular third molars in a Jordanian population.

OBJECTIVE: The aim of this study was to evaluate the topographic relationship between the inferior dental canals (IDCs) and the roots of impacted mandibular third molars. METHODS: Preoperative orthopantomograms (OPGs) were examined and the proximity of the IDC to the roots of impacted mandibular third molars was categorized into the following: groups: superimposition, adjacent, perforation, grooving, notching, or none. The categories notching, grooving, and perforation were regrouped together and called the true relationship between the IDC and the root apices. The type of impaction, age, and sex of the patient were also noted. RESULTS: The positional category of 96.1% of the radiographs with bilateral impactions was identical on both sides of the mandible. Out of 2526 impacted mandibular third molars examined, 1146 (45.3%) belonged to the superimposition category, 663 (26.2%) were adjacent, 312 (12.3%) showed grooving, 78 (3.08%) showed notching, and 9 (0.35%) were actually perforating the IDC. The results showed 15.7% of the total cases were in true relationship with the IDC. There was a significant association (p = 0.000) between patient's age and true relationship. CONCLUSIONS: Identical positional relationship of the bilateral impacted third molars to the IDC was noted in 96.1% of the radiographs. The position of the IDC in relation to the roots of impacted third molars varied according to the patient's age.

Adolescent↗

Dentin bridge formation after white mineral trioxide aggregate (white MTA) pulpotomies in primary molars.

PURPOSE: To evaluate, clinically and radiographically, the dentin bridge formation potential of white mineral trioxide aggregate (white MTA) when used in pulpotomy treatments in primary molars. METHODS: A total of 23 primary molars received a pulpotomy treatment using white MTA followed by stainless steel crown restoration and controlled 6 months after treatment. RESULTS: Clinical and radiographic success was 100% as none of the molars showed any clinical or radiographic pathological signs. Reparative dentin deposition was found in some of the cases: stenosis was present in 69.2% of the pulp canals from mandibular molars and formation of dentin bridges was seen in 11.5% of the pulp canals from mandibular molars 6 months after treatment with white MTA.

Aluminum Compounds↗

A survey on supernumerary molars.

The contemporary literature concerning the etiology, frequency, and classification of supernumerary teeth, specifically molars, is reviewed in this article. Also, methods for their early detection, as well as the prognosis and treatment of supernumerary molars, are discussed. Eight cases at the University of Athens and 105 others obtained from the literature were subjected to statistical analysis to examine sexual dimorphism and the position, impactions, and bilateral presence of supernumerary molars. Super-numerary molars occurred more frequently in the maxilla (79.7%), often were impacted (88.7%), and were found bilaterally 23.9% of the time. No great difference was found between the sexes in the frequency of supernumerary molars.

Adolescent↗

A retrospective radiographic evaluation of primary molar pulpectomies.

Relatively few long-term studies have been performed to evaluate the clinical success of one-appointment pulpectomies in primary molar teeth. The purpose of this retrospective study was to evaluate the radiographic appearance of nonvital primary molars before and after treatment with a one-appointment formocresol pulpectomy technique. The mean length of time since pulpectomy treatment for the 62 primary molars was 40.2 months. Based upon strict radiographic criteria, the one-appointment pulpectomy procedure was considered to be successful in 82.3% (51) of the cases, with 3.2% (2) of pulpectomized primary molars needing retreatment, and 14.5% (9) of pulpectomy procedures failing. The pulpectomy procedure is indicated when inflammation of the pulpal tissue extends into the root canals, and possibly involves the periapical and/or bifurcation areas. This procedure provides an alternative to extraction and space maintenance when the pediatric dentist encounters a nonvital primary molar tooth.

Child, Preschool↗

[Application of composite resin inlays to deciduous molars--a clinical observation of the resin onlay].

Although composite resin has been used as an aesthetic restorative material, wear and fracture of the resin of fracture of the tooth structure are likely to occur when the size of the dental cavities are large. In addition to the lack of the aesthetic value, clinical results of prefabricated metal crown revealed several problems which were caused by the wear of the metal and the ill-adaptation of the cervical margin. In the present study, 50 devitalized deciduous molars were treated with composite resin onlays which were designed to cover the entire occlusal surface of the deciduous molar, and the clinical results were evaluated for a 6 month period. Additionally, for the purpose of simplification of the laboratory process for making resin onlays, ready-made occlusal shells were fabricated. The variety of the prepared shell size consisted of 7 sizes for the first deciduous molar, 9 sizes for the upper second deciduous molar and 10 sizes for the lower deciduous molar. The following results were obtained. 1) A partial resin fracture at the peripheral area of the mesio-buccal cuspid was found in five cases out of 50. 2) A glossy appearance on the surface of the onlay which was created by coated unfilled resin disappeared after 6 months of observation. 3) In relation to the resin onlay, when the antagonistic tooth was restored with prefabricated metal crowns, holes were made by attrition on all the crowns within a 3-4 month period.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗

[Pit sealing of deciduous and permanent molars. In vivo evaluation].

The authors studied a fissure sealant retention in deciduous molars and first permanent molars. The assessment of the sealant retention was performed at six months intervals. After eighteen months study period a greater sealant on the deciduous molars was observed, in a decreasing order as follow: upper and lower first permanent molars. It was also shown that greatest loss of sealant occurred on the disto occlusal pit of the upper first permanent molars.

Child↗