Outpatient anesthesia for oral surgery in a juvenile with Leigh disease.
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We report a case of anesthesia for elective outpatient third molar extraction in a juvenile with Leigh disease, a progressive neurodegenerative disorder related to respiratory chain deficiency. This syndrome usually presents in infancy and is characterized by nervous system dysfunction and respiratory abnormalities. Anesthesia has been reported to aggravate respiratory symptoms and frequently precipitate respiratory failure. Preoperative swallowing difficulty or respiratory symptoms should be carefully diagnosed, because they can be a warning sign of postoperative complications or mortality. Adverse effects of anesthesia may quickly lead into metabolic acidosis. Anesthetics should be carefully chosen that do not interfere with mitochondrial respiration, which can lead to lactic acidosis. (+info)
Third molar influence on dental arch crowding.
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The aim of the present study was to measure the dental arches in order to assess the potential influence of third molars on lower incisor crowding. Changes in dental arch dimensions were assessed in 47 patients (36 females, 11 males) three years following either removal of the third molars or deciding to leave them in situ. A dental pantomogram (DPT) was taken at the start of the study and plaster study models were obtained at both the beginning and end of the observation period. The study models were used to measure crowding, and to prepare photocopies for linear measurements of the dental arch (length and width). Using the DPT, the ratio of retromolar space to the width of the crown of the third molar was calculated using the method originally described by Olive and Basford and later modified by Ganss (Ganss ratio). The results showed that the measurements of crowding and arch length and width had changed in 12 lower and two upper dental arches. The relationship between these results and the Ganss ratio was statistically significant. Calculation of the Ganss ratio may therefore assist investigations into the development of dental arch crowding and also help determine the indications for third molar removal. (+info)
Histological and immunohistochemical studies of tissue engineered odontogenesis.
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The successful regeneration of complex tooth structures based on tissue-engineering principles was recently reported. The process of this regeneration, however, remains poorly characterized. In this study, we have used histochemistry to examine the regeneration process of tissue engineered teeth in order to determine the cell types that give rise to these engineered tooth structures. Porcine third molar tooth buds were dissociated into single-cell suspensions and seeded onto a biodegradable polyglycolic acid polymer scaffold. Following varying periods of growth in rat hosts, the specimens were evaluated by histology and immunohistochemistry. Aggregates of epithelial cells were first observed 4-6 weeks after implantation. These aggregates assumed three different shapes: a natural tooth germ-like shape, a circular shape, or a bilayer-bundle. Based on the structure of the stellate reticulum in the dental epithelium, the circular and bilayer-bundle aggregates could be clearly classified into two types: one with extensively developed stellate reticulum, and the other with negligible stellate reticulum. The epithelial cells in the circular aggregates differentiated into ameloblasts. The continuous bilayer bundles eventually formed the epithelial sheath, and dentin tissue was evident at the apex of these bundles. Finally, enamel-covered dentin and cementum-covered dentin formed, a process most likely mediated by epithelial-mesenchymal interaction. These results suggest that the development of these engineered teeth closely parallels that of natural odontogenesis derived from the immature epithelial and mesenchymal cells. (+info)
Interfacial chemistry of moisture-aged class II composite restorations.
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Under in vivo conditions, the adhesive/dentin bond at the gingival margin of class II composite restorations can be the first defense against substances that may penetrate and ultimately undermine the composite restoration. Deterioration of this bond during aqueous aging is an area of intense investigation, but to date, the majority of our techniques have provided only an indirect assessment of the degrading components. The purpose of this study was to analyze the in situ molecular structure of adhesive/dentin interfaces in class II composite restorations, following aging in aqueous solutions. Class II preparations were cut from 12 unerupted human third molars, with a water-cooled, high-speed, dental handpiece. The prepared teeth were randomly selected for restoration with single bond (SB) and Z100 (3M). Teeth were restored, as per the manufacturer's directions, under environmental conditions that simulated humidity and temperature characteristics of the oral cavity. Restored teeth were kept in sterile Delbecco's phosphate saline for 48 h or 90 days. The samples were sectioned occlusogingivally and micro-Raman spectra were acquired at approximately 1.5 microm spatial resolution across the composite/adhesive/dentin interfaces at the gingival margins. Samples were wet throughout spectral acquisition. The relative intensity of bands associated with the adhesive in the interfacial region decreased dramatically after aqueous storage. This decrease in concert with the similar depth of dentin demineralization provides direct spectroscopic evidence of leaching of adhesive monomer from the interface during the 90 days of storage. SB adhesive infiltrated 4-5 microm of 12-microm demineralized dentin at the gingival margin. After 90 days of aqueous storage, SB adhesive infiltration was reduced to approximately 2 microm, leaving approximately 10 microm of demineralized dentin collagen exposed at the gingival margin. The unprotected collagen at the gingival margin of the aged class II composite restorations was disorganized, suggesting hydrolysis of the collagen, with 90 days of aqueous storage. (+info)
Reduction of Pax9 gene dosage in an allelic series of mouse mutants causes hypodontia and oligodontia.
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Missing teeth (hypodontia and oligodontia) are a common developmental abnormality in humans and heterozygous mutations of PAX9 have recently been shown to underlie a number of familial, non-syndromic cases. Whereas PAX9 haploinsufficiency has been suggested as the underlying genetic mechanism, it is not known how this affects tooth development. Here we describe a novel, hypomorphic Pax9 mutant allele (Pax9neo) producing decreased levels of Pax9 wild-type mRNA and show that this causes oligodontia in mice. Homozygous Pax9neo mutants (Pax9neo/neo) exhibit hypoplastic or missing lower incisors and third molars, and when combined with the null allele Pax9lacZ, the compound mutants (Pax9neo/lacZ) develop severe forms of oligodontia. The missing molars are arrested at different developmental stages and posterior molars are consistently arrested at an earlier stage, suggesting that a reduction of Pax9 gene dosage affects the dental field as a whole. In addition, hypomorphic Pax9 mutants show defects in enamel formation of the continuously growing incisors, whereas molars exhibit increased attrition and reparative dentin formation. Together, we conclude that changes of Pax9 expression levels have a direct consequence for mammalian dental patterning and that a minimal Pax9 gene dosage is required for normal morphogenesis and differentiation throughout tooth development. (+info)
Morbidity of third molar extraction in patients between 12 and 18 years of age.
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OBJECTIVE: An analysis is made of the incidence of complications following third molar surgical extraction in patients between 12 and 18 years of age. PATIENTS AND METHOD: A retrospective study was conducted of 390 surgical extractions of upper and lower third molars in 173 patients operated upon under locoregional anesthesia during the year 2000 in the Master in Oral Surgery and Implantology of Barcelona University Dental School (Spain). The patients were divided into three age groups (A: 12-14 years, B: 15-16 years, C: 17-18 years). The reason for extraction, the degree of dental development, and third molar position, angle and impaction were recorded. Finally, the association of these variables to the appearance of postoperative complications was analyzed. RESULTS: Most patients were females (66.9%), and the age group in which most extractions were carried out (62.8%) corresponded to Group C (17-18 years). The main reason for extraction was orthodontist indication (40.5%), closely followed by prophylaxis (39.5%). The existence of clinical manifestations was an indication for extraction in 20% of cases. The postoperative complications rate after the extraction of the global 390 molars was 15.6%. In Groups A, B and C the complication risks were 17.4%, 19% and 13.7%, respectively. All complications were reversible and of short duration. One case each of inferior alveolar nerve paresthesia and lingual nerve paresthesia was recorded, which subsided after one and two months, respectively. CONCLUSIONS: There were no significant differences in complications between the three age groups. An increased tendency towards complications was observed in females, and the percentage of postoperative problems increased. (+info)
Analgesic efficacy of diclofenac versus methylprednisolone in the control of postoperative pain after surgical removal of lower third molars.
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OBJECTIVE: To compare the analgesic efficacy of methylprednisolone (corticoid) versus diclofenac (nonsteroidal antiinflammatory-NSAID-) after surgical removal of lower third molars. STUDY DESIGN: Prospective study on 73 patients for the surgical removal of their lower third molars. These patients were separated in two groups at random: a diclofenac group and a methylprednisolone group. A record card was filled in with preoperative and postoperative epidemiological and clinic data. The pain level assessment was made on a semiquantitative and an analogical visual scales and in relation to the amount of rescue analgesics consumed. Pain levels were measured at 1, 8, 24, 48 and 72 hours. In order to make a broad study of data, BMDP program was used for statistics. RESULTS: In the pain described by patients in the analogical visual scale there were no differences between groups as a whole. There were no differences in the amount of rescue analgesics consumed. CONCLUSIONS: There is less pain in the corticoid group but not as to justify its routine use. (+info)
Effects of co-administered dexamethasone and diclofenac potassium on pain, swelling and trismus following third molar surgery.
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BACKGROUND: The apparent interactions between the mechanisms of action of non-steroidal anti-inflammatory drugs (NSAIDS) and steroids suggest that co-therapy may provide beneficial inflammatory and pain relief in the absence of side effects. The aim of the study was to compare the effect of co-administered dexamethasone and diclofenac potassium (diclofenac K) with diclofenac K alone on the postoperative pain, swelling and trismus after surgical removal of third molars. PATIENTS AND METHODS: A prospective randomized double-blind study was conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Nigeria. A total of 100 patients were randomly allocated to two treatment groups of dexamethasone (prophylactic 8 mg and postoperative 4 mg IV) and diclofenac K (50 mg Oral before and after surgery), and diclofenac K alone (as with first group). The overall analgesic efficacy of the drug combinations was assessed postoperatively by determination of pain intensity using a category rating scale. Facial swelling was measured using a tape measure placed from tragus to gonion to tragus, while interincisal mouth-opening of patients was measured using a vernier calibrated caliper pre-operatively and post-operatively. RESULTS: Co-administration of dexamethasone and diclofenac K was significantly superior to diclofenac alone for the relief of pain (P < 0.05), and facial swelling up to post-operative 48 hour (P < 0.05). However, there was no significant difference for trismus relief between the two medication protocols (P > 0.05). CONCLUSION: This study illustrates enhanced effects of co-administered dexamethasone and diclofenac K on short-term post-operative pain and swelling, compared to diclofenac potassium alone in third molar surgery. (+info)