Category Archives: Uncategorized

Heat mouldable impression tray Part 2

Mandibular stock trays will sit on top of large mandibular tori, or at best scrape the lingual tissue covering the tori during the impression, again resulting in complications during the impressioning phase for any application. In the past, solutions included cutting down the lingual flanges to make them end superior to the mandibular torus, or to take a preliminary impression which was not seated fully and then from the model fabricated, make a custom tray and re-impress. Clinicians have also attempted to use maxillary trays to impress lower arches, however it is difficult if not impossible to retract the tongue to accomplish this procedure. Yung-tsung has suggested taking a maxillary tray, cutting out the palatal portion and adding utility wax to create a tray that will capture lingual tori. Until now, there has not been an easy solution for satisfactorily modifying a stock tray to impress a maxillary tuberosity, unless one removes the centre of a plastic tray, and most often it required a first impression doing the best one could clinically, and then following with a final impression utilizing a custom tray fabricated from the initial model. Continue reading

Heat moldable impression tray Part 1

Intra-oral bony growths of all types, present a clinical challenge for the dental team attempting to capture accurate detail for final impressions of crown and bridge, removable prosthetics, oral appliances, accurate opposing models, study models, and whitening trays. Stock impression trays often can’t be seated to depth, because they get hung up on these bony anatomical variants, or the bony protuberances can cause pain during the impressioning procedure, as there is often only a thin membrane of covering tissue which is easily irritated. Lingual tori may also limit the space for the tongue and can result in speech impediment. Even though these bony areas can create a clinical challenge with impressioning, these areas are prime sites for harvesting autogenous bone for bone grafting of dental implants and can be used for multiple reconstructive procedures such as nasal reconstruction. Continue reading

Tooth development Part 2

Bell stage

The bell stage is known for the histodifferentiation and morphodifferentiation that takes place. The dental organ is bell-shaped during this stage, and the majority of its cells are called stellate reticulum because of their star-shaped appearance.


Tooth development Part 1

Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. Although many diverse species have teeth, non-human tooth development is largely the same as in humans. For human teeth to have a healthy oral environment, enamel, dentin, cementum, and the periodontium must all develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth weeks, and permanent teeth begin to form in the twentieth week. If teeth do not start to develop at or near these times, they will not develop at all. Continue reading

Curve of Spee

In Anatomy, the Curve of Spee (called also von Spee’s curve or Spee’s curvature) is defined as the curvature of the mandibular occlusal plane beginning at the tip of the lower cuspid and following the buccal cusps of the posterior teeth, continuing to the terminal molar. According to another definition Curve of Spee is an anatomic curvature of the occlusal alignment of teeth, beginning at the tip of the lower canine, following the buccal cusps of the natural premolars and molars, and continuing to the anterior border of the ramus. Ferdinand Graf von Spee, German embryologist, (1855–1937) was first to describe anatomic relations of human teeth in the sagittal plane. Continue reading

Caries diagnosis Part 3

Although the evidence shows that many diagnostic methods are less than desirably accurate, current diagnostic interpretations still must be used until new, more sensitive, techniques are available and validated. The evidence-based reports supported previous caries experience and pathologically low salivary flow rate as indicators of significant risk. Most studies from the systematic reviews involved children and excluded root caries, adults, and anterior teeth. Therefore, the clinician must extrapolate reportedly successful preventive and arresting/remineralization techniques from children to adults, root caries, and anterior teeth. In the absence of clear evidence on adequately sensitive diagnostic methods for detecting early noncavitated lesions and risk assessment indicators, clinicians need guidelines for treatment. Continue reading

Caries diagnosis Part 2

Numerous risk indicators, that is, characteristics or measurements that assist in the prediction of caries, whether or not they are involved in caries causation, have been suggested for children. Unfortunately, more of the supportive data come from cross-sectional correlations with accumulated caries experience than from prospective, protocol-based incidence studies. The prospective studies employed different combinations of potential predictors in a variety of populations, varied considerably in sample size and quality, and have not produced a broadly applicable index or set of criteria for risk assessment. More and higher-quality comprehensive, longitudinal, multifactor studies of implicated risk indicators are needed to obtain firm support for their associations with caries incidence, to clarify the strengths of these associations in differing populations, and to reveal the extent to which the risk indicators provide independent as opposed to redundant information. In addition, although the nature of the disease process suggests that many of the proposed indicators may well be appropriate throughout life, validation studies in adult populations are largely absent or incomplete. Continue reading

Muscles of Mastication

During mastication, four muscles of mastication (or musculi masticatorii) are responsible for adduction and lateral motion of the jaw. Other muscles, usually associated with the hyoid such as the sternohyomastoid, are responsible for opening the jaw. Continue reading

Consent – Dental Protection Part 11

Aspects of consent

The General Dental Council is involved in various matters of consent, as ethical issues which reflect upon the professional conduct of a dentist. The General Dental Council identifies the main ethical principles of getting consent as:

Consent – Dental Protection Part 10

A patient sometimes consents to a particular line of treatment because of the apparent advantages or benefits as described by the dentist. Care should be taken to ensure that the information given is balanced and accurate, and that any claims (as to likely success) can be substantiated. Statements such as “your crown will last for life”, or “your molar root treatment will be 100% successful” or “I guarantee you will have no problem” may dramatically weaken the value and validity of the consent contained. Continue reading