Behaviour of primary incisor caries: a micromechanical study

OBJECTIVES: To date, there has been no attempt to assess the mechanical properties of the entirety of a smooth-surface carious lesion in primary teeth, despite the fact that these lesions are not only common, but clinically challenging. Therefore, the aim of this study was to describe the hardness and modulus of elasticity across smooth surface lesions of primary incisors. STUDY DESIGN: An in vitro study of the micromechanical properties of primary incisors. MATERIALS AND METHODS: Carious primary incisor teeth were set in resin, sectioned and polished. A series of indentations using the ultra-micro-indentation system were conducted in fully hydrated carious and sound dentine from the minimally affected pulpal region towards the tooth surface. A single set of indentations were duplicated for sound dentine. RESULTS: Although the mechanical properties of the carious dentine varied between the test teeth, the median hardness of the surface, middle and inner (pulpal) region of the carious dentine was 0.01, 0.10 and 0.28 GPa, respectively. The modulus of elasticity of the surface, middle and inner (pulpal) carious dentine was 0.12, 2.16 and 5.98 GPa, respectively. The mechanical properties of the sound dentine varied less, and were consistent between the pulpal and surface regions. Examination of the individual series of indentations indicated that, although the majority of the test teeth showed a decrease in the mechanical properties from the 'unaffected dentine' to the surface of the lesion, in the last 300-500 microm, both the hardness and modulus of elasticity showed a dramatic increase. CONCLUSIONS: This study has confirmed that the carious process has a deleterious effect on the mechanical properties of dentine in primary incisors. This, in turn, increases the likelihood of restorative failure. However, the slight increase in mechanical properties seen at the surface of the carious lesion suggests an increase in mineral content.     

An audit of the UK national cancer referral guidelines for suspected oral mucosal malignancy

BACKGROUND AND OBJECTIVE: This study aimed to assess the effectiveness of the UK National Guidelines for identifying patients with potentially malignant oral disease which were introduced in 2000. DESIGN: Retrospective audit. SETTING: The oral medicine unit in a university teaching hospital in London. METHODS: All new referrals over a one year period were retrospectively reviewed in a departmental audit to evaluate guideline effectiveness. Reasons for referral and final diagnosis were compared in a randomly selected sub-population. RESULTS: Four hundred and eighty-seven of 901 new patients referred were classified as having potentially malignant disease from the referral letter. In a randomly selected subgroup of 241 patients, 18 actually had malignant (8) or dysplastic lesions (10). Of 75 patients referred with a persistent oral ulcer, only nine were actually malignant or dysplastic. Eight of 116 patients referred with a white patch and none with red patches were found to have dysplastic or malignant lesions. The criteria failed to identify three carcinomas and two severely dysplastic lesions (15% of the malignant or dysplastic lesions). All of the latter had been referred by primary care physicians with orofacial pain of unknown cause. CONCLUSIONS: UK National Guidelines discriminate poorly between potentially malignant and other oral mucosal disease.     

Double pathological fracture of mandibula caused by actinomycotic osteomyelitis: a case report

Actinomycosis is an uncommon chronic granulomatous infection that cause formation of abscesses and cutaneous fistula. In mandibular actinomycosis the alveolar bone and mandibular body are usually not involved and the pathogenetic mechanisms of the actinomycotic infiltration is unknown. The patients usually report pain at the alveolar arch with development of a purplish-red swelling firmly attached to the mandibula; the fibrous tissue produces the continued development of new cutaneous fistulas with oncoming pus-secretion. An uncommon case of actinomycotic osteomyelitis with a double pathological fracture of mandibula is reported. Ortopanoramic X-ray and computed tomography scan of the mandibula are effective and relevant diagnostic procedures to quantify the entity and site of the osteolitic areas and to define the precise position of fractures. In association with the intravenous infusion of benzilpenicillina, daily local irrigations of rifamicina have been performed. Moreover, the patient underwent surgical drainage of abscesses with accurate curettage of osteomyelitic lesions and several biopsies of the trabecolar bone and fistulas were taken. It has been also necessary to perform a mandibular blockage using a resinal plaque anchored on premolars. To reach a precise diagnosis, an histopathological examination togheter with batterioscopic-coltural examination is needed. Antibiotic therapy alone is not a sufficient therapeutic approach and surgical treatment must be quickly performed with clean up of the osteomyelitic lesions and contention of fractures by alveolar blockage for at least 40 days.     

Nonsurgical treatment with rapid mandibular canine retraction via periodontal ligament distraction in an adult with a Class III malocclusion.

A woman with a Class III malocclusion was a poor candidate for orthognathic surgery. An orthodontic treatment plan was developed that incorporated a relatively new and rapid process of canine distraction. The mandibular first premolars were extracted, correcting the anterior crossbite, the Class III canine relationship, and the Class III facial appearance. The canines were distracted, through the periodontal ligament, into the extraction sites. Dental distraction is a breakthrough for orthodontics, especially for adults with critical anchorage requirements.