L C Levitch | PubMed Health

PubMed1994

Non-carious cervical lesions.

Non-carious cervical lesions are commonly encountered in clinical practice and present in a variety of forms. A knowledge of the aetiology of these lesions is important for preventing further lesions, halting progression of lesions already present, and determining appropriate treatment. The most commonly cited aetiological factors thought to lead to the development of cervical lesions are erosion, abrasion and tooth flexure. Evidence supports a multifactorial aetiology for non-carious cervical lesions. The purpose of this paper is to review the evidence for each of these aetiological factors as it relates to the development of non-carious cervical lesions. Specific features of cervical lesions linked to these factors, including their morphology, location, prevalence and distribution by age and sex will be discussed. Suggestions for future research into the cause and prevention of non-carious cervical lesions will be presented.

Dental Occlusion, Traumatic↗

PubMed1993

How dentists classified and treated non-carious cervical lesions.

All North Carolina general dentists were shown color photographs of three non-carious cervical lesions. A fourth picture showed cervical caries. Respondents were asked how they defined each lesion, its cause, treatment and frequency of appearance in practice. Cervical caries was identified and treated by almost all responding dentists, but they applied more varied terms, causes and treatments to non-carious defects.

Clinical Competence↗

PubMed1992

The mechanism of suckling in two species of infant mammal: miniature pigs and long-tailed macaques.

Suckling is the form of feeding unique to infant mammals. The mechanism used by infant mammals to withdraw liquid from the nipple is the subject of considerable debate. Suckling has been examined in two species of infant mammals: miniature pigs and long-tailed macaques. In both species radio-opaque markers were inserted into the tongue and jaws; the movements of the jaw and tongue (and also of specific regions within the tongue) plus the movement of milk containing barium were studied by high-speed cineradiography (100 and 150 frames/sec). In the case of macaques, simultaneous pressure transducer recordings were also made. In both species, liquid moved out of the nipple as the intraoral space was expanded by a combination of tongue movement (negative pressure pumping) coupled with jaw opening. There was no evidence for expression (positive pressure on the nipple) in either species, strongly supporting the view that a suction mechanism is responsible for acquisition of milk from the nipple. Subsequent intraoral transport was different in the two species. The pigs used a second pump mechanism at the base of the tongue to transport liquid through the pillars of the fauces into the valleculae. The monkeys used a "squeeze-back" mechanism similar to the transport mechanism documented for adult macaques. Further work with other species can test our tentative hypothesis that all mammals use a negative pressure suction for acquisition, but, as is true for adult mammals, infants may use different transport mechanisms to form and move the bolus.

Animals↗