The influence of anatomical, pathophysiological and other factors on periodontal healing after impacted lower third molar surgery. A multiple regression analysis.

A multifactorial approach has been used to identify some predictors of postoperative intrabony defects (IBD) on the distal surface of the adjacent second molar (M2) after impacted lower third molar (M3) surgery. The material consisted of 215 lower third molar removals, performed on 144 persons (age range 16-53 years; mean 27.2 years). The postoperative examination took place 2 years after impaction surgery and included both clinical and radiographic variables. Statistically significant (5% significance level) predictors of IBD found in stepwise multiple regression analyses were: (1) preoperative intrabony defect M2 distal; (2) age at the time of surgery; (3) size of contact-area M3/M2; (4) root resorption M2 distal; (5) probing dept distal surface of adjacent first molar postoperatively; (6) pathological follicle M3. The regression model with IBD as regressand produced a total R2 of 0.45. When the regressand was the difference between IBD and the preoperative intrabony defect, the regression analysis explained 62% of the variance (R2 = 0.62). These regression models explained the variance in terms of the size of the remaining postoperative intrabony defect as well as in terms of periodontal healing after impacted lower third molar surgery.

Analgesic efficacy and side-effect profile of paracetamol/codeine and paracetamol/dextropropoxyphene after surgical removal of a lower wisdom tooth.

A double-blind randomized analgesic trial was carried out on 180 patients undergoing surgical removal of an impacted lower wisdom tooth. The patients took their first dose of either 1000 mg paracetamol plus 60 mg codeine or 650 mg paracetamol plus 65 mg dextropropoxyphene when pain appeared after the decline of the local anaesthesia. If needed, another two doses were available during the observation period (less than or equal to 10 h). The analgesic efficacy of paracetamol/codeine was overall superior to paracetamol/dextropropoxyphene in all variables. Sufficient pain relief was obtained in most patients. The pain reduction after the first dose was 64% in the group receiving paracetamol/codeine compared with 53% in the group receiving paracetamol/dextropropoxyphene and the mean durations of effect of the first dose were 6.6 and 5.8 h, respectively. Side-effects appeared in all patient groups but were most frequent in women taking paracetamol/codeine.

Healing of experimental excisional wounds in the rat palate. III. Effects of radiation on wound healing.

The effects of radiation on the healing of standardized, excisional wounds in the palate was studied in 48 white rats of the Sprague-Dawley strain. A single dose radiation of respectively 16 Gy to one group and 20 Gy to another was given three weeks before the excisional wounds were made. Healing of the wounds was followed for three weeks in the irradiated groups and also in one control group. Three rats were killed at 0, 1, 3, 5, 7, 10, 14 and 21 days from each group. The wound area was measured with a square millimeter grid on photographs taken with standardized technique and histological analysis of serial sections from the wound region performed. The results showed that the wound healing was heavily disturbed in the 20 Gy group with more or less extended bone necrosis and inflammatory reactions with a large open wound surface after three weeks, whereas in the 16 Gy group the healing was somewhat slower than the control group but not as complicated as in the 20 Gy group.

Voltaren as an analgesic after surgical removal of a lower wisdom tooth.

In a controlled trial, before having a lower wisdom tooth surgically removed, 190 patients were blindly randomized to 2 parallel groups. One group received 100 mg Voltaren (diclofenac-sodium) before surgery and then 50 mg 3 times a day for 5 days; the other group in Sweden widely used fixed combination tablets (acetylsalicylic acid 500 mg, caffeine 50 mg, aprobarbital 20 mg, codeine phosphate 10 mg) in the highest recommended dose, 2 tablets when needed at most 3 times a day. Twice a day the patients recorded pain and swelling on 100 mm visual analogue scales. Patients treated with Voltaren had significantly less pain and swelling (p less than 0.001). Furthermore, they had significantly fewer days away from work (p less than 0.01). The study indicates that visual analogue scales may also be useful in assessment of swelling and that Voltaren in a fixed dosage offers a promising alternative against postoperative pain and swelling.

Effect of long-term application of snuff and herpes simplex virus 1 on rat oral mucosa. Possible association with development of oral cancer.

In an animal model, the life-long effects of snuff administration were assessed alone and in combination with infection with herpes simplex virus (HSV-1). It was shown that exposure to standard and alkaline snuff and to HSV-1/snuff induced mild to severe hyperplasia, hyperorthokeratosis, varying degrees of vacuolization and acanthosis in the squamous epithelium, as well as atrophic and ulcerated lesions. Ulcerations and mild dysplasia of the squamous epithelium were seen most frequently in HSV-1/snuff-exposed rats, with moderate dysplasia in the crevicular epithelium. Rats exposed to snuff or to HSV-1 and snuff had a higher incidence of tumours or tumour-like conditions than control rats. Squamous-cell carcinoma of the oral cavity was found exclusively in rats exposed to snuff or to the combination of HSV-1 and snuff. Papillary squamous hyperplasia of the forestomach was found only in rats exposed to snuff or to HSV-1 and snuff in combination. The incidence of malignant tumours was significantly higher (p less than 0.05) in the group of rats exposed to snuff and HSV-1/snuff than in control animals.

Oral lichen planus: hypersensitivity to dental restoration material.

67 patients with oral lichen planus of the atrophic-erosive or reticular plaque type were examined. Dental amalgam in contact with mucosal lesions was present in 64 patients, and gold fillings in 33. Patch testing with a standard procedure was performed with components of dental fillings. 11 patients (16%) reacted to at least one of the mercury compounds compared to 8% in a reference group. Most positive reactions were caused by elemental mercury and ammoniated mercury. No patient reacted to gold or copper. Readings at days 10-14 did not increase the number of responders. 13 patients were patch tested with palladium; all were negative. It is not clear whether in the mercury-positive patients allergy to dental amalgam is a causative or aggravating factor, or merely on epiphenomenon.

Healing of experimental excisional wounds in the rat palate. II. Histological study of electrosurgical wounds.

Healing of standardised, excisional, electrosurgical wounds in the palatal mucosa of rats was studied during a three-week period. The excision margins were made with a specially constructed biopsy instrument with a diameter of three millimetres. The soft tissue was removed with electrosurgical equipment (Siemens Standard Radiotom 612) and uncovered bone tissue was left for secondary healing. Five rats were killed 0, 1,3,5,7,10,14 and 21 days after the surgical procedure. In another group, standardised sharply dissected wounds were made and the healing followed for three weeks using the same experimental design. Photometric measurements were made of the wounds after various time intervals and serial sections from palatal blocks were subjected to light-microscopic examination. In the control group the clinical healing was completed in three weeks, whereas in the experimental group part of the wound area was still non-epithelialised on day twenty-one. Photometric measurements showed that healing was delayed in the electrosurgical group during the first week but accelerated between day 7 and day 14. On day 14 the electrosurgical wounds were still 60% larger than the sharply dissected ones. The histological examination showed a complicated healing pattern, with necrosis deep in the bone tissue and sequestration of bone fragments on the wound surface. On day 21 the repair process in the connective tissue was still going on, with elimination of damaged tissue elements.

Severe oral lichen planus: remission and maintenance with vitamin A analogues.

Twenty-five patients with chronic oral lichen planus, usually of the atrophic-erosive type, were treated for 2 months with Etretinate 0.6 mg/kg b.w./day, followed for 4 months by Etretinate 0.3 mg/kg/day, or 0.1% Tretinoin in an adhesive base. Complete resolution or improvement was seen in 85% of the lesions after first treatment. The number of patients with oral soreness and pain was significantly reduced (p less than 0.001). During the second treatment, the improvement was maintained or even increased in about 70% of the patients, irrespective of the mode of treatment. Treatment was discontinued in one patient owing to moderately increased serum transaminase levels. The number of drug-related drop-outs was significantly lower than in a previous study utilizing an etretinate dose of about 1 mg/kg/day (p less than 0.05). Other adverse effects were minor and tolerable. Retinoids offer an effective mode of therapy for severe oral lichen planus.

Healing of experimental excisional wounds in the rat palate. (I) Histological study of the interphase in wound healing after sharp dissection.

Healing of standardized, excisional wounds in the rat palate has been studied in 40 rats for a period of 3 weeks. The excisional wound were made with a specially constructed biopsy instrument with a diameter of 3 mm. The soft tissue was removed by sharp dissection and uncovered bone tissue was left for secondary healing. 5 rats were killed at 0, 1, 3, 5, 7, 19, 14 and 21 days after the surgical procedure. Photometric measurements were made of the wound at the different control times and serial sections from blocks including the palate, alveolar process and teeth were subjected to light-microscopical examination. Clinical healing was completed within 3 weeks. Photometric measurements showed an almost 50% reduction of the defect between the 7th and 10th days. Histological examination initially revealed a pronounced inflammatory reaction both in the sub-epithelial connective tissue and in the haversian canals of the bone tissue. The epithelialization progressed from the wound borders, the epithelial cells trying to avoid interference with the inflammatory cell infiltrate. Reduction of the wound surface proceeded by contraction of the wound margins as well as by epithelial cell migration. Empty osteocyte lacunae in the surface layer of the bone tissue beneath the wound and the presence of small nectrotic bone fragments indicated that damage to the bone tissue had occurred during the exposure period. After 3 weeks, the defect was completely covered with epithelium although epithelial rete pegs had not yet developed in the central part of the former defect.

Severe oral lichen planus: treatment with an aromatic retinoid (etretinate).

A double-blind study of twenty-eight patients with severe oral lichen planus treated with etretinate (75 mg daily) or a placebo for 2 months, showed that the oral retinoid had a marked beneficial effect. Nine non-responders who had received only placebo then entered an open cross-over study and they responded well to etretinate. Etretinate thus provided effective symptomatic relief for severe oral lichen planus, but side-effects were common, and six patients stopped treatment because of them.

A clinical, histomorphological and histochemical study on snuff-induced lesions of varying severity.

The oral lesions in 50 habitual snuff-dippers were graded on a four-point scale. The patients' tobacco and drinking habits were studied by means of a questionnaire. From each patient a biopsy was taken for histomorphological and histochemical analysis. A correlation between snuff habits and the clinical degrees was found, as well as between the snuff habits and certain superficial and deeply located cell changes. The incidence of keratinized lesions, sialadenitis and slight dysplasia (based on subjective evaluation under a light microscope) was higher than previously reported. Presence of dysplastic changes could not be predicted by means of the parameters which characterise the snuff habit or from the clinical grade. The histomorphological and histochemical results were interpreted as showing that the mucosa react to snuff inducing hyperplasia in the basal cell layers. In the surface layer indications of lethal damage were found. The overall stromal reaction to snuff was weak. However, the salivary glands and excretory ducts exhibited degenerative changes which were found to be more severe than the pathological changes in the surface epithelium.

Snuff-induced lesions of the oral mucosa - an experimental model in the rat.

An experimental model in the white rat has been developed in order to study the influence of snuff on oral mucosa. A test canal in the lower lip, with one orifice buccally to the incisors and one on the lip side, was created by surgical means. The connection between the canal and the oral cavity was made to ensure the presence of saliva in the canal so that physiological conditions resembling those of the oral cavity were obtained. The canal was filled with snuff morning and night 5 days a week. The mean value for the maximal retention time of the snuff was 6 h. The animals tolerated the dose and time of exposure without signs of severe toxic symptoms. Histological examination of the canals after 9 months of exposure to snuff showed a mildly to moderately hyperplastic epithelium with hyperorthokeratosis. Locally deep proliferations of epithelium with acanthotic rete pegs could be seen. In the stratum basale hyperplasia with disturbed polarity and hyperchromatic nuclei and single mitosis were noted.

Topical tretinoin therapy and oral lichen planus.

The treatment of severe forms of oral lichen planus is still relatively unsatisfactory. In this controlled study, 0.1% tretinoin in an adhesive base was used in 23 patients. Fifteen other control patients were similarly treated with the vehicle alone. In the tretinoin-treated group, 71% of the atrophic-erosive lesions improved while 29% improved from the vehicle (P less than .05). Reticular-plaque lesions improved in 74% from tretinoin and in 15% from the vehicle (P less than .001). Irritation from tretinoin occurs and thorough usage information is mandatory.