Evolution of the Temperament Theory and Mental Attitude in Complete Denture Prosthodontics: From Hippocrates to M.M. House.

Some 2,500 years ago Hippocrates developed the "Temperament Theory" of the four humors (fluids) he identified as blood, phlegm, yellow bile, and black bile which then led to the ancient medical concept known as "humorism." In Greco-Roman medicine, these humors were believed to be the influencers of an individual's relative wellness or ill-health, served as a means to classify illnesses, and subsequently guided medical diagnosis and treatment. Centuries later modifications to Hippocrates' hypothesis were suggested for use in dentistry when selecting denture teeth and later as a means to classify the mental status and personality of complete denture patients. This paper examines the historic transition of the terminology, characteristics, and thinking behind the four humors with mention of key thinkers in this journey. Of particular note is the evolution in the application of this theory from its suggested use in medicine, proposed by Hippocrates, to the descriptions of mental attitudes and personalities of complete denture patients first described by Neil and subsequently popularized by M. M. House.

Single implant and crown versus fixed partial denture: A cost-benefit, patient-centred analysis.

Single implants and their crowns have high survival rates that exceed the survival rates for fixed partial dentures on teeth and most but not all publications have determined single implants are more cost-effective than 3-unit fixed partial dentures. Both initial root canal treatment and retreatment are more cost-effective than tooth extraction and rehabilitation with a single implant and crown.

A comparison of gingival display with a requested smile, Duchenne smile, grimace of disgust, and funnel-shaped expression.

STATEMENT OF PROBLEM: A patient's smile may not elicit the maximum amount of maxillary gingiva. PURPOSE: The purpose of this study was to measure the amount of gingival display with 4 different facial expressions. MATERIAL AND METHODS: Video images of 91 randomly selected adults were evaluated to measure the height of gingival display at the maxillary anterior teeth and first premolars when participants were asked to give their biggest smile (requested smile), make a Duchenne smile, mimic an intense grimace of disgust (grimace), and produce a funnel-shaped expression (funnel). Measurements were compared with the Friedman Test with post hoc comparisons (α=.05 for all tests). RESULTS: The intraclass correlation coefficient was (95% CI)=0.913(0.623, 0.984). At the central and lateral incisors, the grimace and funnel expressions produced the greatest amounts of gingival display. At the canines and the first premolars, both smiles (requested and Duchenne) exhibited the largest amount of gingival display of the 4 facial expressions. CONCLUSIONS: Neither smile type revealed a significantly greater amount of gingival display above the maxillary central or lateral incisors but the grimace and funnel facial expressions did (P ≤.001). Above the maxillary canines, both smiles displayed a significantly greater amount of gingiva than did the funnel expression (P<.001), but only the Duchenne smile displayed a greater amount than did the grimace expression (P=.05). Superiorly to the maxillary first premolars, both smile types revealed significantly greater amounts of soft tissue when compared with the other 2 facial expressions (P<.001).

Esthetic smile preferences and the orientation of the maxillary occlusal plane.

STATEMENT OF PROBLEM: The anteroposterior orientation of the maxillary occlusal plane has an important role in the creation, assessment, and perception of an esthetic smile. However, the effect of the angle at which this plane is visualized (the viewing angle) in a broad smile has not been quantified. PURPOSE: The purpose of this study was to assess the esthetic preferences of dental professionals and nondentists by using 3 viewing angles of the anteroposterior orientation of the maxillary occlusal plane. MATERIAL AND METHODS: After Institutional Review Board approval, standardized digital photographic images of the smiles of 100 participants were recorded by simultaneously triggering 3 cameras set at different viewing angles. The top camera was positioned 10 degrees above the occlusal plane (camera #1, Top view); the center camera was positioned at the level of the occlusal plane (camera #2, Center view); and the bottom camera was located 10 degrees below the occlusal plane (camera #3, Bottom view). Forty-two dental professionals and 31 nondentists (persons from the general population) independently evaluated digital images of each participant's smile captured from the Top view, Center view, and Bottom view. The 73 evaluators were asked individually through a questionnaire to rank the 3 photographic images of each patient as 'most pleasing,' 'somewhat pleasing,' or 'least pleasing,' with most pleasing being the most esthetic view and the preferred orientation of the occlusal plane. The resulting esthetic preferences were statistically analyzed by using the Friedman test. In addition, the participants were asked to rank their own images from the 3 viewing angles as 'most pleasing,' 'somewhat pleasing,' and 'least pleasing.' RESULTS: The 73 evaluators found statistically significant differences in the esthetic preferences between the Top and Bottom views and between the Center and Bottom views (P<.001). No significant differences were found between the Top and Center views. The Top position was marginally preferred over the Center, and both were significantly preferred over the Bottom position. When the participants evaluated their own smiles, a significantly greater number (P< .001) preferred the Top view over the Center or the Bottom views. No significant differences were found in preferences based on the demographics of the evaluators when comparing age, education, gender, profession, and race. CONCLUSIONS: The esthetic preference for the maxillary occlusal plane was influenced by the viewing angle with the higher (Top) and center views preferred by both dental and nondental evaluators. The participants themselves preferred the higher view of their smile significantly more often than the center or lower angle views (P<.001).

The incidence of maxillary sinus membrane perforation during endoscopically assessed crestal sinus floor elevation: a pilot study.

Transcrestal sinus membrane elevation is a surgical procedure performed to increase the bone volume in the maxillary sinus cavity. Because of visual limitations, the potential for maxillary sinus membrane perforations may be greater than with the lateral approach technique. The aim of this study was to macroscopically investigate ex vivo the occurrence of sinus membrane perforation during surgery using 3 transcrestal sinus floor elevation methods. Twenty fresh human cadaver heads, with 40 intact sinuses, were used for simultaneous sinus membrane elevation, placement of graft material, and dental implants. Real-time sinus endoscopy, periapical digital radiographs, and cone-beam computerized tomography (CBCT) images were subsequently used to evaluate the outcome of each surgical procedure. Perforation rates for each of the 3 techniques were then compared using a significance level of P < .05. No statistically significant differences in the perforation rate (P = .79) were found among the 3 surgical techniques. Although the sinus endoscope noted a higher frequency of perforations at the time of implant placement as compared with instrumentation or graft insertion, the difference was not statistically significant (P = .04). The CBCT readings were judged to be more accurate for identifying evidence of sinus perforations than the periapical radiographs when compared with the direct visualization with the endoscope. This pilot study demonstrated that a sinus membrane perforation can occur at any time during the sinus lift procedure, independent of the surgical method used.

CAD/CAM fabricated complete dentures: concepts and clinical methods of obtaining required morphological data.

The clinical impression procedures described in this article provide a method of recording the morphology of the intaglio and cameo surfaces of complete denture bases and also identify muscular and phonetic locations for the prosthetic teeth. When the CAD/CAM technology for fabricating complete dentures becomes commercially available, it will be possible to scan the denture base morphology and tooth positions recorded with this technique and import those data into a virtual tooth arrangement program where teeth can be articulated and then export the data to a milling device for the fabrication of the complete dentures. A prototype 3-D tooth arrangement program is described in this article that serves as an example of the type of program than can be used to arrange prosthetic teeth virtually as part of the overall CAD/CAM fabrication of complete dentures.

The art of scientific writing: how to get your research published!

The purpose of this article is to provide potential authors with a contemporary guide to scientific writing. It is in essence a handbook that covers the planning for a scientific publication from inception of the project or study to manuscript preparation and, ultimately, acceptance by a journal. Major topics such as manuscript formatting, data analysis, use of charts, graphs and images, reference formats, and manuscript submission are presented.

Effects of a chemical disinfectant on the physical properties of dental stones.

PURPOSE: This study compared the effects of an antimicrobial agent (Asepto-Sol) on the physical properties of types III, IV, and V gypsum casts made from two types of impression materials. MATERIALS AND METHODS: Selected physical properties of five gypsum-based dental stones (Prima-Rock, Ortho Stone, New Fujirock, Die-Keen, Microstone) and two resin-based dental stones (Resin-Rock, Instone) were evaluated using an addition silicone impression material (Reprosil) and an irreversible hydrocolloid (Jeltrate Plus). In group 1, Asepto-Sol solution replaced water as the gauging liquid for the seven dental stones. The mixed gypsum was poured directly onto impressions of two master dies using two impression materials. In group 2, impressions made with both impression materials were sprayed with the Asepto-Sol solution, left for 10 minutes, rinsed for 30 seconds with tap water, and poured with each dental stone mixed with deionized water. In group 3 (control), the gypsums were mixed with deionized water and the mixed stone was poured directly into impressions, with no exposure to Asepto-Sol. The physical properties evaluated for the gypsum specimens were linear dimensional change, detail reproduction, Knoop hardness, and transverse strength. RESULTS: The linear dimensional stability, detail reproduction, and transverse strength tests were relatively unaffected by the use of Asepto-Sol, with few exceptions. Detail reproduction appeared to be least affected by Asepto-Sol, and changes in Knoop hardness were noted but results differed among the seven dental stones. However, New Fujirock was not ideally matched with Jeltrate Plus, and no stone specimens could be produced. CONCLUSION: Whether mixed with the gypsum powder or sprayed on impressions, Asepto-Sol solution did not adversely affect the physical properties of the dental stones tested.

Reducing bacterial counts in dental unit waterlines: distilled water vs. antimicrobial agents.

BACKGROUND: This study evaluated five chemical disinfectants to compare their abilities to improve dental unit waterline quality and assess their effects, if any, on the biofilm layer. METHODS: Sixty new dental units, with a closed-circuit water system, were used to compare microbial levels in DUWLs treated with five antimicrobials: Listerine, Bio 2000, Rembrandt, Dentosept, and sodium fluoride to a control group of sterile distilled water alone over a six-week period. For all units, the waterlines were filled with solution, left overnight, and then flushed for 30 seconds with sterile distilled water the following morning prior to patient treatment. Waterlines were examined for biofilm buildup using scanning electron microscopy and colony-forming-unit counts. RESULTS: The sodium fluoride and the four chemical antimicrobials reduced the microbial count to 200 cfu/ml or less. Only samples taken from dental units receiving the control treatment (distilled water with no added antimicrobial) failed to meet ADA's stated goal. Examination of the SEMs revealed an apparent decrease in the biofilm mass but not elimination, despite repeated treatment with the four antimicrobial materials. CONCLUSIONS: Even in a closed-circuit water system, distilled water alone cannot reduce microbial contamination of dental treatment water from dental unit waterlines to the 200 cfu/ml ADA stated goal. However, water treated with Listerine mouthrinse, Rembrandt mouthrinse, Bio 2000, 0.5 percent sodium fluoride and Dentosept, did meet the microbial reduction goal. The biofilm apparently was reduced in volume, but not entirely eliminated. CLINICAL SIGNIFICANCE: The ADA goal of a maximum of 200 cfu/ml was achieved using any of five chemical antimicrobials and distilled water in a closed-water system. Despite the successful reduction in microbial contamination of the dental treatment water, the biofilm was not completely eliminated. Biofilm elimination and prevention would be needed through some other means.

Reducing bacterial counts in dental unit waterlines: tap water versus distilled water.

BACKGROUND: The maximum recommended level of microbial contamination of water from dental unit waterlines (DUWL) is 200 colony-forming units per milliliter (CFU/mL). This article addresses the importance of water selection in achieving that standard. METHODS: Microbial contamination in water samples from 75 new dental units, with a closed-circuit water system, were compared using combinations of tap water and sterile distilled water with and without two chemical disinfectants (bleach and 0.12% chlorhexidine gluconate, Bio2000) over a six-week period. Baseline tap water samples were collected and tested initially. RESULTS: The microbial plate counts of seven tap water specimens (controls) ranged from 4 to 95 CFU/mL. These results were well below both the 500 CFU/mL standard for public drinking water and the 200 CFU/mL goal for dental treatment water. However, when passed through dental units, no significant bacterial reduction was achieved for samples of tap water (Group 1), tap water treated with bleach (Group 2), or tap water treated with Bio2000 (Group 4). Only water samples from dental units using Bio2000 alone (Group 3) or a combination of sterile, distilled water with Bio2000 (Group 5) met or exceeded the 200 CFU/mL standard. CONCLUSIONS: Using tap water alone or tap water with bleach did not improve water quality. However, the American Dental Association (ADA) standard for reduced microbial contamination of dental unit waterlines was met using Bio2000 and distilled water treated with Bio2000. CLINICAL SIGNIFICANCE: The ADA standard of 200 CFU/mL was achieved using a closed water system and distilled water treated with Bio2000. Using 100% Bio2000 is also effective, but more costly.

A multicenter interracial study of facial appearance. Part 2: A comparison of intraoral parameters.

PURPOSE: This article compares interracial or gender differences of six intraoral dental parameters among six racial groups (African American, Caucasian, Chinese, Hispanic, Japanese, and Korean). MATERIALS AND METHODS: The same 253 patients participating in part 1 were included in this portion of the study to evaluate six intraoral parameters. The data were collected and analyzed using a one-way analysis of variance, followed by the Tukey-Kramer test for honestly significant difference when statistically significant differences were found (P < .05). RESULTS: Women displayed significantly more gingival tissue in four of the six races, and African Americans displayed significantly more gingival tissue than any other race. Women had significantly more missing teeth than men in three of the six races studied. Japanese subjects had significantly fewer missing teeth and smaller maxillary central incisors than all other groups except Caucasians. Women had significantly narrower maxillary central incisors in three of the races. There was a significantly higher prevalence of Angle Class III relationships in Chinese subjects. The Japanese had significantly more Class II molar relationships than other races. CONCLUSION: Racial and gender differences were found in gingival tissue display, the number of missing teeth, maxillary right central incisor crown width, and Angle molar classification, but not in the amount of vertical or horizontal overlap of the anterior teeth.

A multicenter interracial study of facial appearance. Part 1: A comparison of extraoral parameters.

PURPOSE: This study was undertaken to compare the facial appearance of patients from six racial groups (African American, Caucasian, Chinese, Hispanic, Japanese, and Korean) for interracial and/or gender differences and to determine if "norms" existed. MATERIALS AND METHODS: A total of 253 subjects (144 men and 109 women) ranging in age from 18 to 41 years (mean age 26.5 years) were evaluated using a standardized protocol. The data were collected and analyzed to establish reference ranges for seven frontal and six profile extraoral parameters. Mean scores were compared by race and gender using a one-way analysis of variance, followed by the Tukey-Kramer test for honestly significant difference when statistically significant differences were found (P < .05). RESULTS: There were no significant differences for any of the seven frontal or six profile extraoral parameters between men and women. No significant differences were found between racial groups for five of the seven frontal and one of the six profile extraoral parameters. CONCLUSION: Most of the frontal facial parameters and one profile extraoral parameter might be considered norms for male and female patients of different ethnic origins. Additional research with larger patient populations would be needed to confirm or refute these trends.