Radiographic follow-up of impacted third molars from age 20 to 32 years.

Nineteen patients (13 male, six female) with 34 impacted third molars, 21 in the mandible and 13 in the maxilla were radiographically followed from age 20 to 32. All were examined clinically and panoramic radiographs were taken at baseline and at the end of the study. Radiographic analysis included resorption of teeth, enlargement of the follicle, development of the root, change in inclination of the third molar, state of impaction, relative depth of the third molar in bone and relation to the ramus of the mandible and to the second molar tooth. In the mandible, the mean change in inclination was 19 degrees and the percentage of teeth with changed angulation was 76%. In the maxilla, only 23% of the teeth changed their inclination. The state of impaction (soft tissue, partially in bone, completely in bone) had changed for 44% of the teeth. According to the questionnaire, no pain or symptoms in the region of the third molars were reported by 74% of the students during the 12-year period. It is concluded that considerable radiographic changes, without notable symptoms, may occur involving inclination of the tooth and state of impaction in impacted third molars after the usual age of eruption.

Thermographic imaging of postoperative inflammation modified by anti-inflammatory pretreatment.

PURPOSE: The aim of this study was to assess the usefulness of thermography in detecting the postoperative inflammatory reaction after third molar removal. PATIENTS AND METHODS: Thermographic images (NovaTherm; Novamedix Ltd, Hampshire, England) of both cheeks were obtained on the first and seventh postoperative days after removal of impacted mandibular third molars under local anesthesia in 30 patients (15 men, 15 women). The unoperated contralateral side served as a control. One of the following pretreatments was given immediately before the operation: diclofenac (Voltaren; Novartis, Espoo, Finland) 150 mg orally (rapid-release 50 mg and prolonged-release 100 mg, n = 15), diclofenac 100 mg orally (prolonged-release) and 50 mg intramuscularly (n = 11), or placebo (n = 4). RESULTS: The postoperative skin surface temperature on the operated side was significantly higher than that on the unoperated side. The thermal difference was 0.9 degrees C +/- 0.1 degrees C on the first postoperative day and declined significantly by the seventh day to 0.3 degrees C +/- 0.1 degrees C (both P < .001). The thermal difference in patients receiving diclofenac preoperatively was significantly smaller (0.8 degrees C +/- 0.1 degrees C at day 1 and 0.2 degrees C +/- 0.1 degrees C at day 7) than in patients receiving placebo (1.6 degrees C +/- 0.1 degrees C at day 1 and 0.8 degrees C +/- 0.3 degrees C at day 7, P < .001). However, with equal doses of diclofenac, the combination of rapid-release and prolonged-release tablets orally was more effective in reducing skin temperature than an orally administered prolonged-release tablet combined with intramuscular injection (P < .001). CONCLUSION: Thermography is a suitable method to measure the inflammatory reaction related to third molar removal. Thermal changes are significant and are decreased by the nonsteroidal anti-inflammatory drug diclofenac.

Long-term evaluation of estimates of need for third molar removal.

PURPOSE: The aim of this study was to evaluate the estimates on need for third molar removals made at age 20 after 12 years. PATIENTS AND METHODS: The series consisted of 81 university students followed from age 20 to 32 years. At baseline and at study end, these students were clinically examined, and panoramic radiographs were taken. At baseline in 1982, a qualified oral surgeon had made estimates on need for removal of third molars within 5 years; 75% of students needed removals. Actual treatment performed was evaluated after 12 years. A questionnaire served to determine symptoms related to third molars during the 12-year period. RESULTS: During the follow-up, one or more third molars had been removed from 67% of the former students. A total of 155 third molar removals had been estimated, but by age 32 years the percentage actually removed was only 59%. Of the 79 third molars taken out at the Finnish Student Health Service, 77% were initially estimated to need a surgical procedure, but actually 66% were simply extracted. Most were removed at around age 27 years. According to the questionnaire, 67% of the students were asymptomatic in the third molar region during 12 years. CONCLUSION: Because need for surgical removal decreases during early adulthood, routine prophylactic extraction of asymptomatic third molars in young adults cannot be recommended. Well-defined indications for prophylactic removals are needed.

Change in clinical status of third molars in adults during 12 years of observation.

PURPOSE: The aim of the study was to follow the clinical changes in third molar status during a 12-year period in patients aged 20 to 32 years. PATIENTS AND METHODS: The study was based on a follow-up of 81 university students (32 men, 49 women). They were clinically examined and panoramic radiographs were taken at baseline (mean age, 20.7+/-0.5 years) and at the end of the study (mean age, 32.6+/-0.6 years). RESULTS: The students had 285 unerupted, partially erupted, or fully erupted third molars at the beginning of the study, and 150 at the end. On final examination, 115 teeth were erupted. During the first 6 years from age 20 to 26, various clinical changes took place in the status of the third molars. In the second 6 years, until age 32, the two main changes were either removal or eruption. During the 12-year follow-up, 22% of third molars erupted, a few even after 26 years of age; the percentage of third molars removed was 42%. CONCLUSION: Third molars undergo continuous clinical change at least up to the age of 32 years.

Malpractice claims for permanent nerve injuries related to third molar removals.

On the basis of the register of the Finnish Patient Insurance Association, the aim of this study was to examine malpractice claims for nerve injuries associated with third molar removals and determine whether they are concentrated among specialists, among less experienced dentists, or in certain geographic areas. During 1987-93 there were 139 claims for permanent sensory or motor disturbances related to removal of lower third molars in Finland. The lingual nerve was injured in 54% and the inferior alveolar nerve in 41% of the claims. In 91% of the cases the injury occurred in relation to surgical removal of the tooth and in 6% in relation to simple extraction. The claims were distributed among 123 dentists, of whom 78% were dental surgeons, 15% specialists in oral and maxillofacial surgery, and 7% other specialists. These figures represented 2% of the dental surgeons and 26% of the oral surgeons in Finland (P< 0.01). More than half the claims were associated with dentists with less than 10 years' experience. Claims originated more often from the eastern and northern (rural) areas of Finland than from urban areas (3.8 claims versus 2.4 claims per 100,000 inhabitants, P < 0.05). Compensation was paid to the patients in two-thirds of the cases, indicating that the dentists authorized to decide claims very often considered these injuries avoidable. Therefore, proper diagnosis, treatment planning, surgical techniques, and detailed patient information must be emphasized. In cases where risks are obvious, referral to an oral surgeon is recommended.

Traumatic injuries among university students in Finland.

A questionnaire dealing with the incidence of traumatic injuries was sent to 1,000 randomly selected 3rd-year university students in Finland; 617 students responded adequately. Of those, 177 (28.7%) reported a combined total of 281 accidents and 323 separate injuries requiring medical or dental treatment during the preceding 3 years. The accidents resulted in 1,061 days of official sick leave, and one third of the accidents caused permanent sequelae to the affected students. Almost half of all accidents had been sustained during sports activities and 14% in traffic. Only 0.5% of the accidents were classified as having occurred in the university environment or during activities directly related to studies. Alcohol was involved in 10.1% of the accidents; 45% of the injuries affected the lower extremities, and 22% the upper extremities. Most of the injuries were related to the students' active lifestyles and keen interest in sports.

Factors predisposing to postoperative complications related to wisdom tooth surgery among university students.

In a retrospective study among 550 Helsinki University students 20 to 30 years old, factors predisposing to postoperative complications from removal of lower jaw wisdom teeth were evaluated. Patient records and panoramic tomograms covering the period from 1990 to 1993 were examined; 50 patients (9.1%) had postoperative complications after removal of a wisdom tooth. The most common complications were alveolar osteitis (2.9%), postoperative infection (2.6%), postoperative bleeding (1.5%), and dysesthesia of the lower lip or tongue (1.1%). Factors associated with increased postoperative complications were mesiohorizontal position of the tooth, deep impaction of the tooth, and use of oral contraceptives. Before patients undergo surgery for removal of wisdom teeth, those who use oral contraceptives or have difficult tooth impactions should be informed about the increased possibility of postoperative complications.

A comparative prospective clinical study of two single-tooth implants: a preliminary report of 102 implants.

STATEMENT OF PROBLEM: Treatment of tooth loss in the anterior maxilla can involve difficult functional, esthetic, and psychologic problems, especially in young patients with otherwise good dentition. PURPOSE: The purpose of this study was to provide a preliminary comparative evaluation of two implants (ITI and Astra) in single-tooth restorations. MATERIAL AND METHODS: This prospective study of 102 single-tooth replacements with 56 ITI and 46 Astra dental implants was performed in 82 patients at the Finnish Student Health Service Foundation. One Astra implant was lost before loading. The overall survival rate of the implants was 97.8% for Astra implants and 100% for the ITI system. After the initial healing period of at least 6 months, the remaining 101 implants (56 ITI, 45 Astra) were free of periimplant infection and revealed no detectable mobility. Radiographs did not reveal signs of periimplant radiolucencies. All 101 implants received single-tooth crowns. RESULTS: Periimplant parameters and acceptable implant function were examined and demonstrated satisfactory results with preestablished clinical parameters and radiographs at 1 year. During the observation time the mean marginal bone loss was 0.13 mm with Astra implants and 0.11 mm with ITI implants. Subjectively all patients were satisfied with their single-tooth restorations supported by either ITI or Astra dental implants. CONCLUSION: The favorable results of this short-term study support the application of the two implant systems for single-tooth restorations, especially in the anterior region of the maxilla.

A device to predict lower third molar eruption.

This study was designed to create a transparent device to be superimposed on a panoramic tomogram taken of a patient at age 20 years to make predictions of future eruption or impaction of lower third molars. The device was developed from data on 40 lower third molars initially retained at age 20 years; one half of these remained impacted, and the other half of them erupted by age 26 years. Tracings were made from panoramic tomograms taken at age 20 years. The critical point for prediction in the overlay was the intersection of a horizontal reference line and the anterior border of the ascending ramus. To estimate this critical separation line, Bayes' Decision Theory was used. The sum of false negatives and false positives was least at a distance of 14.5 mm from the distal surface of the second molar. Mesial from this point, the probability of impaction was 76%; distal from this point, the probability of eruption was 72%. Tested against 35 initially unerupted lower third molars, the predictions made by the device and the actual clinical findings were in conformity in relation to 97% of the test teeth. It could thus be concluded that the method was simple to use and may prove a good addition for predicting lower third molar development.

Mast cell-derived tryptase in odontogenic cysts.

Inflammatory and developmental cysts of the jaws are relatively common bone destructive lesions in the human maxillofacial skeleton but their pathogenesis is still poorly understood. In this study the role of mast cells (MC), and mast cell tryptase in particular, was evaluated in the pathophysiology of bone resorption and jaw cyst formation in different types of cysts. The distribution of MC and the amount of tryptase in histological tissue sections were determined by immunohistochemistry using monoclonal antihuman tryptase antibodies and the results were quantitated by using an image analyzing system. The amount of tryptase was further studied by Western-blotting and measurement of trypsin-like activity from the neutral salt extracts obtained from different types of jaw cysts. In contrast to control tissue, high trypsin-like activities and abundant immunoreactive tryptase were observed in the extracts of all types of cysts studied (radicular, dentigerous and keratocyst). In tissue sections the highest amount of tryptase-positive staining was observed in radicular cysts (mean 6.2% of reference area) and the lowest amount in keratocysts (mean 2.1% of reference area, P < 0.01). MC were found to be located in inflammatory cell-rich tissue areas and just beneath the cyst epithelium. Importantly, MC located at the border of bone were observed to be degranulated, indicating high activity of MC and release of tryptase at the regions of early bone destruction. Based on previous findings addressing the role of mast cell tryptase in proteolytic cascades, and the known association of MC with osteoporosis, we suggest that mast cells and mast cell tryptase may contribute significantly to jaw cyst tissue remodelling during growth of a cyst, and to the destruction of the surrounding bone, resulting in jaw cyst expansion.

Characterization of interstitial collagenases in jaw cyst wall.

Neutral salt extracts of 14 specimens of jaw cysts were prepared. Histopathological analysis showed that the specimens consisted of 6 radicular cysts, 6 dentigerous cysts, 1 residual cyst, and 1 odontogenic keratocyst. One periapical granuloma, 1 dental follicle and a sample of clinically healthy oral mucosa were similarly processed and used as controls. Measurement of collagenase activity by monitoring the formation of specific degradation products of type I and II collagen in solution by SDS-PAGE demonstrated that all the cyst extracts contained collagenase, some of which was endogenously activated. Cyst wall collagenase preferably degraded type I over type II collagen, which suggests that the degradation was due to MMP-1 (matrix metalloproteinase-1) rather than the MMP-8 type. This was further supported by the doxycycline-inhibition profile of cyst collagenase, which was similar to that of MMP-1. Part of the cyst wall collagenase was in latent proenzyme form and probably derived, at least in part, from the newly synthesized intracellular collagenase pool. Latent cyst collagenase was efficiently activated with phenylmercuric chloride and to a lesser extent by gold (I) thioglucose and NaOCl. Western-blotting, using specific antibodies against collagenase from human polymorphonuclear neutrophilic leukocytes (MMP-8) and from fibroblasts (MMP-1), revealed a typical 55/45 kDa doublet; also MMP-8 in the latent 80 kDa form and fragmented to 65 kDa active species were found. These results suggest the presence of MMP-1 and, to a lesser extent, MMP-8 type collagenase in the cyst wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Effective postoperative pain prevention through administration of bupivacaine and diclofenac.

The efficacies of bupivacaine and lidocaine together with a preoperatively administered single-dose oral combination of normal- and sustained-release preparations of diclofenac in preventing postoperative pain after third molar removal were compared in a double-blind crossover study. Bilaterally impacted lower third molars were removed in two sessions. Each patient was given one type of local anesthetic on one session and the other in the second. Pain was recorded using a visual analog scale. When the diclofenac combination (150 mg) was given before the operation, postoperative analgesia was better with bupivacaine plus diclofenac than with lidocaine plus diclofenac. Twenty-five out of 40 patients preferred bupivacaine to lidocaine for local anesthesia. It is possible to achieve effective postoperative pain prevention by combining bupivacaine and preoperative normal- and sustained-release preparations of diclofenac.

Preoperative intravenous diclofenac for postoperative pain prevention in outpatients.

Fifty patients undergoing a standard removal of an impacted lower third molar were given a single dose of 75 mg sodium diclofenac or saline (placebo) intravenously before operation, on a double-blind basis. Pain was measured postoperatively by means of a visual analogue scale hourly for the first 8 h and during the first and second days after operation. Administration of diclofenac resulted in greater pain relief than administration of placebo for the first 3 h after surgery, whereafter the treatments did not differ. The results suggest that intravenous preoperative diclofenac may be useful in some clinical situations but generally it probably offers little benefit over the corresponding oral treatment.

Third molars as an acute problem in Finnish university students.

The study was carried out to determine the risk of acute disease of third molars in young adult patients. The subjects in this case-control study were 100 consecutive university students who complained of third molar problems when making an appointment. The third molars were mostly mandibular, partly erupted, and distoangularly oriented. Severity of discomfort and interference with daily activities were graded by the patients on average as 5.0 (SD +/- 2.7) and 3.6 (SD +/- 2.9), on a scale from 0 through 10. Distoangular lower third molars caused the most discomfort and interfered most with activities of patients. The risk of acute disease in patients with distoangularly oriented third molars was 3.6 times that in other patients. Bivariate analysis showed that if the follicle of a distoangular third molar were enlarged, the risk of acquiring acute disease was 44 times that in other patients. It was concluded that early removal of partially erupted and distoangularly oriented lower third molars is recommended, especially when they are associated with an enlarged follicle.

A comparison of diclofenac with and without single-dose intravenous steroid to prevent postoperative pain after third molar removal.

The efficacy of 40 mg of methylprednisolone given intravenously before operation in combination with orally administered rapid-release and sustained-release diclofenac preparations in preventing postoperative pain after third molar removal was studied. The administration of methylprednisolone and diclofenac resulted in greater pain relief than did administration of diclofenac alone.

Postoperative pain prevention by a single-dose formulation of diclofenac producing a steady plasma concentration.

The preoperative single-dose oral administration of a combination of rapid- and slow-release diclofenac (Voltaren, Ciba-Geigy, Basel, Switzerland) preparation in a placebo-controlled trial proved to be more effective in postoperative pain prevention following third molar removal than the combination of intramuscular diclofenac and an oral depot formula.

Assessing the eruption of lower third molars on the basis of radiographic features.

To determine radiographic features by which one could estimate whether lower third molars are likely to erupt after the age of 20 years, university students with a total of 84 unerupted or partially erupted lower third molars were followed up. Five radiographic features of each third molar were measured from the panoramic tomogram taken at age 20 years, and the status of third molars was examined for a second time at age 26 years. The results showed that the lower third molars that did erupt after the age of 20 years were initially: 1) root formation complete; 2) impacted in soft tissue; 3) vertical; 4) placed at the same occlusal level as the neighbouring second molar; 5) showed sufficient space between the ramus and the second molar. In contrast, the teeth that remained impacted at the age of 26 years showed such initial features as: 1) incomplete root formation; 2) embedding in bone; 3) mesioangularity; 4) situated at the cervical level of the neighbouring second molar. It was concluded that a panoramic tomogram taken at age 20 years revealed radiographic features on which an estimation of future eruption of mandibular third molars could be based.

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.

Prophylactic use of phenoxymethylpenicillin and tinidazole in mandibular third molar surgery, a comparative placebo controlled clinical trial.

A clinical double-blind placebo controlled trial was carried out in 136 patients to test the value of the prophylactic use of phenoxymethylpenicillin and tinidazole in mandibular third molar surgery. The three patient groups were uniform with regard to the background data such as age and weight of the patients and the clinical status of the operated tooth, as well as to the observations made at surgery. No statistically significant differences were found between the study groups in the parameters used for evaluation. The results indicate that neither penicillin nor tinidazole have more effect on postoperative complications following operative extraction of wisdom teeth, than placebo tablets.

Helium-neon laser therapy in the prevention of postoperative swelling and pain after wisdom tooth extraction.

Seventeen patients with symmetrically embedded lower wisdom teeth were selected for this study, intended to evaluate the local effect of soft laser therapy on postoperative pain. Both lower third molars were removed in the same operation. The test side, chosen by lot, was treated using a helium-neon laser (632,8 nm, 8 mW, 50 Hz) for 2 minutes. The other side served as the untreated control side. Facial swelling was measured using a modification of the face-bow technique. Postoperative pain was estimated using a visual analogue scale (VAS). When it became apparent that conventional statistical analysis was revealing no difference in postoperative swelling and pain between the test and the control groups, the study was discontinued for ethical reasons.