Leif Lysell

A study of indications used for removal of the mandibular third molar

To study the indications used for removal of the mandibular third molar, questionnaires were sent to 35 Oral Surgery Clinics in Sweden, out of which 29 clinics participated. In each clinic, the questionnaires were to be recorded for 30 patients. The indications for removal were classified into 15 groups. There were also questions about symptoms as well as eruption status for the molar being removed. The results were based on data from 870 individuals with a mean age of 27 years. More than half of the removed third molars (54%) presented no subjective symptoms. Such symptoms were more frequent in association with fully or partially erupted molars than molars completely covered by soft or bone tissue. The indication for removal was classified as prophylactic in 27% and as orthodontic in 14%. Earlier episodes of pericoronitis consisted of 1/4 of the indications and caries or pulpitis of the third molar made up 13%. Pathologic entities like cysts, tumours and root resorption were registered in less than 3% each, and were more frequent among patients 40 years of age or older.

Pathoses associated with mandibular third molars subjected to removal

OBJECTIVES To measure the prevalence of disease of mandibular third molars referred for removal and to estimate the risk for development of pathoses for two cues. STUDY DESIGN A prospective cohort study on molars subjected to removal was performed. The prevalence of different diseases and the patients age, angular position, and degree of impaction of the molars were registered. Odds ratio for molars with different positions and impaction states were estimated. RESULTS Pericoronitis was found in 64% of cases, caries in the third molar in 31%, periodontitis in association with 8%, caries in the second molar in 5%, and root resorption of the second molar with 1% of the molars with pathoses. Odds ratio was highest for distoangular molars (5.8) and for molars partially covered by soft tissue (6.7). CONCLUSIONS The odds ratio is about 22 and 34 times higher for molars partially covered by soft tissue than for molars completely covered by soft or bone tissue. For distoangular molars the odds ratio is 5 to 12 times higher than for molars in other positions.

Asymptomatic mandibular third molars: Oral Surgeons' judgment of the need for extraction☆

Ten oral surgeons were asked to judge the need for extraction of asymptomatic mandibular third molars. Thirty-six mandibular third molars with equal distribution of angular position, impaction status, and patients sex and age were selected. To estimate the consistency of judgment, the 36 cases were duplicated so that, in all, 72 cases were judged. The judgment of the oral surgeons was compared with that of 30 general dental practitioners (GDPs). The number of mandibular third molars the oral surgeons proposed to extract varied from 3 to 21 of 36 teeth. The mean number of molars proposed for extraction was 12 for the oral surgeons and 13 for the GDPs. There was no third molar that all the observers in the two groups agreed should be extracted. About three times as many observers in both groups proposed extraction of molars partially covered by soft tissue. The oral surgeons were unanimous in their judgment not to extract 11 molars, and the GDPs were also unanimous in judgment not to extract two of these. The mean intraobserver agreement within the two groups was comparable, 94% for the oral surgeons and 92% for the GDPs. We conclude that there is a great variation among oral surgeons in their judgment on the need for removal of asymptomatic mandibular third molars. A similar variation in judgment also was observed among GDPs.

Rating the preventive indication for mandibular third-molar sury the appropriateness of the visual analogue scale

The aim was to determine whether a visual analogue scale (VAS) is an appropriate way for general dental practitioners and oral surgeons to rate their judgement of the indication for therapy of asymptomatic mandibular third molars. Thirty general dental practitioners and 10 oral surgeons had to judge the need for removal of 36 third molars. They were also asked to estimate the strength of the indication for extraction on a VAS. To assess the reliability of the judgment, the 36 cases were duplicated. For each participant, two mean indication indices with 95% confidence limits were calculated, one index for molars proposed to be extracted and one index for molars proposed not to be extracted. Pearsons correlation coefficient was used to estimate the intra-examiner reliability and the correlation between the number of molars proposed for extraction and the mean indication index. The correlation between the number of molars proposed to be extracted and the mean indication index was high (p < 0.001). The intra-examiner reliability was also high, with a mean correlation coefficient of 0.72 for the general practitioners and 0.84 for the oral surgeons. No single judge presented any overlap for the 95% confidence limits for the mean indication index of teeth proposed to be extracted versus teeth proposed not to be extracted. These results indicate that the VAS seems to be an appropriate method for analyzing the judgements on a therapeutic strategy like extraction versus no intervention for asymptomatic mandibular third molars.

Initial Tc-99m diphosphonate uptake in mineralized and demineralized bone implants in rats

Radionuclide imaging has been suggested as a means to assess healing and viability of bone grafts and implants. This study deals with the in vivo uptake of 99mTc-MDP in the initial postoperative period in rats. Isogeneic or xenogeneic bone was implanted in subcutaneous pouches. The isogeneic grafts and implants were treated with saline or freeze-treated or demineralized. The xenogeneic implants consisted of Kiel bone or collagen sponge. One day after surgery, the accumulation of 99mTc after an intraperitoneal injection of 99mTc-MDP was seen in all grafts and implants containing bone mineral independent of prior treatment of the graft and implant. In implants composed of only the organic part of bone, no accumulation was observed. One prerequisite for accumulation of 99mTc-MDP is the presence of the inorganic phase. Thus, the interpretation of the initial postoperative scan is based on whether or not the graft or implant initially contained mineral.

Surgical treatment of juxtaradicular periodontitis

A retrospective study was performed on surgically treated localized juxtaradicular periodontitis. 23 teeth were operated on during the years 1971-1976. The majority of these (79%) were incisors or cuspids. The most common etiological factor was iatrogenic root perforation. The postoperative healing process was completely successful in 57% of the cases.