Although "smile therapy" is still in its infancy, society has already placed a great demand on dentists to evaluate and treat smiles. The smile classification scheme and vocabulary presented in this article will aid in discussions between patient and dentist regarding esthetic treatment. (+info)
The influence of dental to facial midline discrepancies on dental attractiveness ratings.
This study investigated the perception of discrepancies between the dental and facial midlines by orthodontists and young laypeople. A smiling photograph of a young adult female was modified by moving the dental midline relative to the facial midline. Twenty orthodontists (10 males and 10 females) and 20 young adult laypeople (10 males and 10 females) scored the attractiveness of the smile on the original image and each of the modified images using a 10-point scale. The results showed that the images were scored as less attractive both by the orthodontists and laypeople as the size of the dental to facial midline discrepancy increased. The scores were unrelated to the direction of the midline discrepancy (left or right) or to the gender of the judge. Further analysis revealed that the orthodontists were more sensitive than laypeople to small discrepancies between the dental and facial midline. It was estimated that the probability of a layperson recording a less favourable attractiveness score when there was a 2-mm discrepancy between the dental and facial midlines was 56 per cent. (+info)
Current trends in removable prosthodontics.
BACKGROUND: This article discusses trends in the demographics and treatment of the edentulous patient. It is clear that there still is a tremendous need for removable-prosthodontic services today. While the basic process of making dentures has changed little over the past several decades, new materials and techniques can help laboratories and clinicians provide functional, esthetic restorations that offer exceptional value to patients. Implant treatment is a tremendous adjunct to removable prosthodontics in the treatment of edentulous patients, but it is not within the financial reach of all dental patients. CLINICAL IMPLICATIONS: The clinical skills required to deliver excellent complete denture care are also paramount to successful implant prosthodontics (fixed and removable) and esthetic dentistry. Even so, the opportunities to develop these skills and the interest appear to be decreasing at the same time that the need is projected to increase. In service to our patients, the profession must examine this trend closely. (+info)
The influence of maxillary gingival exposure on dental attractiveness ratings.
This study examined the influence of maxillary gingival display on the attractiveness ratings awarded by lay people. One hundred and twenty university students (94 females, 26 males) were shown seven photographs of a male and seven photographs of a female subject, each with varying levels of gingival display ranging from -2 to +4 mm. Attractiveness ratings were recorded on a 10-point numerical scale for each of the photographs. The photographs where the full height of the incisors were revealed and no gingival tissue was visible (0 mm of gingiva) were rated as the most attractive. Gingival display of more than 2 mm was rated as progressively less attractive. Linear regression analysis revealed that those students who had received orthodontic treatment rated the photographs representing the female student as more attractive than those representing the male (P < 0.05). (+info)
Organization of the central control of muscles of facial expression in man.
Surface EMGs were recorded simultaneously from ipsilateral pairs of facial muscles while subjects made three different common facial expressions: the smile, a sad expression and an expression of horror, and three contrived facial expressions. Central peaks were found in the cross-correlograms of EMG activity recorded from the orbicularis oculi and zygomaticus major during smiling, the corrugator and depressor anguli oris during the sad look and the frontalis and mentalis during the horror look. The size of the central peak was significantly greater between the orbicularis oculi and zygomaticus major during smiling. It is concluded that co-contraction of facial muscles during some facial expressions are accompanied by the presence of common synaptic drive to the motoneurones supplying the muscles involved. Central peaks were found in the cross-correlograms of EMG activity recorded from the frontalis and depressor anguli oris during a contrived expression. However, no central peaks were found in the cross-correlograms of EMG activity recorded from the frontalis and orbicularis oculi or from the frontalis and zygomaticus major during the other two contrived expressions. It is concluded that a common synaptic drive is not present between all possible facial muscle pairs and suggests a functional role for the synergy. The origin of the common drive is discussed. It is concluded that activity in branches of common stem last-order presynaptic input fibres to motoneurones innervating the different facial muscles and presynaptic synchronization of input activity to the different motoneurone pools is involved. The former probably contributes more to the drive to the orbicularis oculi and zygomaticus major during smiling, while the latter is probably more prevalent in the corrugator and depressor anguli oris during the sad look, the frontalis and mentalis during the horror look and the frontalis and depressor anguli oris during one of the contrived expressions. The strength of common synaptic drive is inversely related to the degree of separate control that can be exhibited by the facial muscles involved. (+info)
Esthetic periodontal considerations in orthodontic treatment--the management of excessive gingival display.
This paper examines various esthetic periodontal considerations during orthodontic treatment. The management of excessive gingival display caused by altered passive eruption is reviewed, with emphasis on causes, recognition, diagnosis and surgical management of this problem. A case of orthodontic treatment of excessive gingival display associated with altered passive eruption of the maxillary incisors is reviewed to demonstrate appropriate management. With proper diagnosis, soft-tissue periodontal procedures after completion of orthodontic treatment can enhance the patient's final appearance. (+info)
Parental evaluation of quality of life measures following pediatric dental treatment using general anesthesia.
The purpose of this study was to examine (a) parental satisfaction with the dental care their child received under general anesthesia, and (b) perception of the impact of this care on physical and social quality of life. The sample included 45 children (median age 50 months, 26 boys and 19 girls). Data were collected using a 1-page survey instrument completed by the parent at the first follow-up appointment. Dichotomous dependent variables were developed to measure parental satisfaction, dental outcome, and social impact of treatment. There was an overwhelmingly positive impression with dental outcomes (pain relief and improved masticatory efficiency). Parental perceptions in the social dimension were also positive. Parents reported more smiling, improved school performance, and increased social interaction. Relative to overall health, the majority of parents reported an improvement. Logit regression analysis revealed that absence of pain (P < .05) and increased social interaction (P < .01) had a significant impact on parents' perception of overall health. Our findings indicate that dental care under general anesthesia for preschool children has a high degree of acceptance by parents and is perceived to have a positive social impact on their child. (+info)
Signal characteristics of spontaneous facial expressions: automatic movement in solitary and social smiles.
The assumption that the smile is an evolved facial display suggests that there may be universal features of smiling in addition to the basic facial configuration. We show that smiles include not only a stable configuration of features, but also temporally consistent movement patterns. In spontaneous smiles from two social contexts, duration of lip corner movement during the onset phase was independent of social context and the presence of other facial movements, including dampening. These additional movements produced variation in both peak and offset duration. Both onsets and offsets had dynamic properties similar to automatically controlled movements, with a consistent relation between maximum velocity and amplitude of lip corner movement in smiles from two distinct contexts. Despite the effects of individual and social factors on facial expression timing overall, consistency in onset and offset phases suggests that portions of the smile display are relatively stereotyped and may be automatically produced. (+info)