Risk factors associated with short-term complications in mandibular fractures: the MANTRA study-a Maxillofacial Trainee Research Collaborative (MTReC).

INTRODUCTION: Complications following mandibular fractures occur in 9-23% of patients. Identifying those at risk is key to prevention. Previous studies highlighted smoking, age and time from injury to presentation as risk factors but rarely recorded other possible confounders. In this paper, we use a collaborative snapshot audit to document novel risk factors and confirm established risks for complications following the treatment of mandibular fractures. METHODS: The audit was carried out by 122 OMFS trainees across the UK and Ireland (49 centres) over 6 months, coordinated by the Maxillofacial Surgery Trainees Research Collaborative. Variables recorded included basic demography, medical and social history, injury mechanism and type, management and 30-day outcome. RESULTS: Nine hundred and forty-seven (947) patients with fractured mandibles were recorded. Surgical management was carried out in 76.3%. Complications at 30 days occurred 65 (9%) of those who were managed surgically. Risk factors for complications included male sex, increasing age, any medical history, increasing number of cigarettes smoked per week, increasing alcohol use per week, worse oral hygiene and increased time from injury to presentation. DISCUSSION: We have used a large prospective snapshot audit to confirm established risk factors and identify novel risk factors. We demonstrate that time from injury to presentation is confounded by other indicators of poor health behaviour. These results are important in designing trial protocols for management of mandibular fractures and in targeting health interventions to patients at highest risk of complications.

Titanium miniplate removal after joint orthodontic-orthognathic surgery treatment: a 10-year retrospective hospital-based audit.

INTRODUCTION: The reported incidence of titanium miniplate removal after orthognathic surgery varies widely, making delivery of risk information to patients problematic. This variation relates to potential biases introduced during the study design, for example, with the pooling of different patient types, creating heterogeneous study samples. This study reduces sampling bias by limiting the cohort to only consecutive orthognathic cases. The primary aim of the study was to identify the incidence of miniplate removal following orthognathic surgery. The secondary aim was to assess the indications and any risk factors for miniplate removal. METHODS: Data from the clinical records of 907 orthognathic surgery cases treated within a centralised oral and maxillofacial hospital service over a 10-year period were collected by two operators and analysed. Every identified case qualified for inclusion. Patient demographics (age, sex, medical comorbidity, smoking), operations (type of surgery, duration, third molar removal, complications) and the indication, timing and site of miniplate removal were analysed. RESULTS: Only 19 patients required postoperative miniplate removal, with the most common indication being infection (63%). There was no significant difference in any of the factors assessed except that significantly more miniplates were removed from female patients (68%) (p<0.001) and from mandibular sites (84.2%) (p=0.003). CONCLUSIONS: The incidence of miniplate removal for this sample was 2.1%. Female sex and miniplate location in the mandible were the only statistically significant risk factors for miniplate removal.

Anticariogenic effect of fluoridated milk and water in rats.

The aim of the study was to get further experimental data on the anticariogenic effect of sodium fluoride (NaF) when administered in milk or water. Thirty six weanling Osborne-Mendel rats were divided into two experimental groups (A, B) of 12 rats each and two control groups (C, D) of six rats each. During the experimental period of four weeks all animals were superinfected with Strep. mutans (NCTC 10449), kept in an automatic feeding machine and given a cariogenic diet (MIT 301). Group A received sodium fluoride (NaF) in water (15 ppm) and group B in ultra high temperature treated milk. Groups C and D respectively received plain milk and distilled water. Group A did not show significantly lower caries reduction compared with the control groups. Group B had significantly the lowest caries scores compared with all other groups. Scores in group C (plain milk) were lower than those in groups D (plain water). The results suggest that the anticariogenic effect of NaF is more pronounced when the vehicle is milk instead of water.

A randomized, double-blind study of two combined and two progestogen-only oral contraceptives.

A randomized double-blind study of two combined oral contraceptives and two progestogen-only oral contraceptives was conducted using the same protocol at WHO Collaborating Centres for Clinical Research in Human Reproduction in Bombay and Ljubljana of the 518 women admitted to the trial, 123 received mestranol 50 micrograms + norethisterone 1mg (MES 50 + NET 1); 137 received ethinyl estradiol 30 micrograms + levonorgestrel 150 micrograms (EE 30 + LNG 150); 130 received norethisterone 350 micrograms/NET 350); and 128 received levonorgestrel 30 micrograms (LNG 30). At one year, between 52.6 and 61.0 percent of those recruited had discontinued oral contraceptive use for all reasons, and by two years, between 70.5 and 76.5 percent had discontinued the treatment. These rates did not differ between the four treatment groups. However, discontinuation rates for all medical reasons at one and two years, and at two years pregnancy rates and discontinuation rates for bleeding disturbances, were significantly lower in the EE/LNG preparation. The groups receiving the MES/NET, LNG and NET had similar pregnancy rates, discontinuation rates for all medical reasons and all bleeding disturbances. There were two ectopic pregnancies among the 22 pregnancies in the progestogen-only groups. Discontinuation because of headache, dizziness and other central nervous system symptoms were significantly more common in those receiving MES/NET compared to EE/LNG. In contrast, discontinuation for gastro-intestinal disturbances were significantly higher in the EE/LNG combined preparation. Bleeding disturbances in the first few cycles tended to be higher in NET than in the LNG group. The data suggest that greater consideration be given to the benefits and risks of including progestogen-only oral contraceptives in the family planning programmes of some countries.

Practical application of synthetic A and B blood group immunoadsorbents.

The effectiveness of synthetic blood group A and B immunoadsorbents in removing anti-A and anti-B from human sera was evaluated. The sera contained specific alloantibodies and were destined for use as diagnostic reagents. Both Synsorb-A(TM) and Synsorb-B(TM) removed all saline anti-A or anti-B activity from 20 sera tested. All trace of anti-A activity detectable by the indirect antiglobulin test was removed from only 20% of sera; anti-B with similar reactivity was removed from 66% of sera. Specific (wanted) alloantibody titres were reduced by synsorb-A in 60% of sera, but were unaffected by Synsorb-B. Despite these shortcomings, such immunoadsorbents are of value particularly when cells of appropriate phenotype are unavailable for absorptions.

Clinical performance and endocrine profiles with contraceptive vaginal rings containing a combination of estradiol and D-norgestrel.

Contraceptive vaginal rings (CVRs) impregnated with a combination of estradiol and d-norgestrel were studied in 39 women. The rings were inserted as three weeks "in" and one week "out" schedule to allow withdrawal bleeding. Ovulation was inhibited in all cycles and promptly resumed on completion of the treatment cycles. Bleeding control was excellent. Incidence of breakthrough bleeding was 2.11 per cent in 273 cycles studied, with 89 per cent of the cycles within the acceptable range (25 - 35 days). Levels of estradiol after an initial rise were maintained between 50-100 pg/ml and, d-norgestrel levels were relatively constant between 1.8-3 ng/ml during the period while the ring remained in situ. Clinical acceptance was good. The main problem encountered was of spontaneous expulsion of the ring in the toilet, which might be due to the squatting toilet habits of Indian women and laxity of vaginal wall.

PIP: Contraceptive vaginal rings (CVRs) impregnated with a combination of estradiol and d-norgestrel were studied in 39 women. The rings were inserted on a 3 weeks "in" and 1 week "out" schedule to allow withdrawal bleeding. Ovulation was inhibited in all cycles and promptly resumed on completion of the treatment cycles. Bleeding control was excellent. Incidence of breakthrough bleeding was 2.11% in 273 cycles studied, with 89% of the cycles within the acceptable range (25-35 days). Levels of estradiol after an initial rise were maintained between 50-100 pg/ml and, d-norgestrel levels were relatively constant between 1.83 ng/ml during the period while the ring remained in situ. Clinical acceptance was good. The main problem encountered was of spontaneous expulsion of the ring in the toilet, which might be due to the squatting toilet habits of Indian women and laxity of the vaginal wall.

Serum progesterone in women with lactational amenorrhoea.

PIP: A cross-sectional study was conducted to detect the return of ovulation in 56 women with (LA) lactational amenorrhea ranging from 2-12 months. As serum progesterone of 5 ng/ml provides an indirect evidence of ovulation. It was estimated by radioimmunoassay in 4 blood samples collected weekly over a period of 1 month in all the women. 37 women showed persistently low values of progesterone ( 5 mg/ml) throughout the study period. The other 19 women had serum progesterone of 5 ng/ml in 1 or several samples. 13 of these women, however, continued to have LA beyond 1 month in spite of the detection of high circulating progesterone. The possibility of pregnancy was excluded in all of them. The endometrial refractoriness to the circulating steriods is proposed as a mechanism of persistent LA.^ieng

Direct evidence of epithelial-mesenchymal interdependence in situ.

In the basal odontogenic zone of the mandibular incisor of the rat the cytological evidence of the toxicity of 40 mg cyclophosphamide per kg, 24 hours following a single intraperitoneal injection, was confined to the proliferating mesenchyme. Localised loss of precursors of odontoblasts cessation of basal odontogenesis and acellularity of the related part of the pulp ensured. The cells of the internal enamel epithelium bordering this region did not differentiate into ameloblasts and appeared atrophic. Upon recovery of the proliferating mesenchymal cell population odontogenesis was resumed basal to the zone of the cytotoxic injury. Pulpal connective tissue generating irregular dentine advanced from the reconstituted basal zone into the area of pulpal acellularity. This was followed by the differentiation of the peripheral stunted cells of the internal enamel epithelium into ameloblasts and locally delayed resumption of amelogenesis. These observations appear to offer direct evidence of epithelial-mesenchymal interdependence in situ.