Clinico-psychological aspects in the rehabilitation of upper frontal teeth

Abstract

Disharmonies of the dento-gingival composition, following periodontal disease, partial edentations, shape or position anomalies of frontal teeth, modify the smile design. The existing issues described in scientific literature regarding the evaluation and analysis of dento-gingival compositions in a wide smile with the existence of a convencience habitual occlusion, have generated controversy in the assessment of therapeutic results.

The aim of the study was to research the particularities of the clinical picture of disharmonies of the upper frontal dento-gingival compositions, followed by the planning and application of treatments with bioaesthethic therapeutic objectives.

The analysis and synthesis of scientific literature allowed us to systematize the evaluation and analysis methodology of the dento-gingival elements of the smile according to dental, gingival and dentogenic criteria.

Concomitantly, the subjects were investigated using conventional methods of imaging and chromatic analysis.

The subjects presented chronic occlusal disharmonies (convenience habitual occlusion), which required remedial through occlusal equilibration in maximum intercuspation, with the conservation of intermaxillary relations.

The evaluation through the quantification of dento-gingival aesthetic parameters took shape in the form of the guide-schema developed by us, in light of the aesthetic principles of dentistry.

In conclusion, during the staged planning of the cosmetic treatment sequences, one achieved the distinction and compromise between the quantification of aesthetic parameters and the conservation of occlusal parameters.

The clinical implication, according to the evaluation, analysis and cosmetic treatment methodology, supports the claim of remedying the existing convenience habitual occlusion in maximum intercuspation position and the cosmeticisation of dento-gingival compositions.

Keywords: dental rehabilitation, dento-gingival composition,

Introduction. The psychological interpretation of personality in dental compositions.

The facial zones (cerebral, emotional, instinctive), according to morphopsychological interpretations, denote the intelligence, social activity, the intensity of physical life an the personality of an individual and influence their behavioral interaction with the surrounding world. [10]

The oral cavity, especially the anterior dental segment, is the centerpiece of the instinctive zone, consequently immediately attracting the observer’s attention. Therefore, the smile, with its ability to express a plethora of emotions, could often determine how well an individual could function in society. [8, 9, 10] Goldstein, who is widely considered to be the founder of cosmetic dentistry, affirms that a beautiful smile can open new doors, break down barriers and change one’s outlook on life. [6] Frush and Fisher think that a beautiful smile is not necessarily one that brings fame and wealth, but rather a harmonious and expressive smile that complements our personality and keeps our dignity as human beings. [3]

In an article published in 1884 in the Dental Cosmos journal, White J.W. asserted that the dental practitioner should correlate the tooth’s aspect to the facial contour, age and temperament of the patient, applying this theory to systematize the temperamental shapes of the anterior teeth into a series of “nominal sets”. In this regard, White employed Hippocrates’ temperament theory, according to which individuals are divided into 4 temperamental types, based on the ratio of their “bodily humors”:

• Sanguine
• Choleric
• Melancholic
• Phlegmatic [12]

In the middle of the 1950’s, in a series of 6 articles published in The Journal of Prosthetic Dentistry, John P. Frush and Roland D. Fisher presented the foundations of the dentogenic concept in aesthetic restorations. When explaining the meaning of the term, they stated that the “-genic” suffix has the same meaning as in “photogenic”. Consequently, the term “dentogenic” describes an “eminently fitting” restoration in the sense that it enhances the charm, character, dignity and beauty of the patient through an “expressive smile”. In the dentogenic concept, the smile is the primary objective feature of the personality, the expressivity of which will contribute to the pleasant subjective personality of the patient. The authors bring a pertinent argument that regardless whether the patient’s physical aspect is their source of income and fame or not, nature equips us with something far more valuable- the dignity and satisfaction of being an individual with their own personality. Neither the patient, nor the doctor want to overlook this testimony of individuality in the primary objective center of the personality (the smile), whence arises the necessity of its correct interpretation, maintenance and enhancement. [1, 2, 3, 4, 5]

Subsequently, Frush and Fisher describe the dentogenic concept as the inseparable interpretation of three vital factors: sex, personality and age (SPA). Within the SPA factor, the personality occupies the central role, dictating the fundamental shape of the tooth, which is then adjusted to sex and age. [3, 5]

The dentogenic theory departs from the existence of a personality spectrum that comprises the following characteristics:

• Vigorous- rough, aggressive, angulated, muscular and primate
• Moderately pleasant- robust, healthy an intelligent aspect
• Delicate- fragile, frail and rounded. [3, 5]

Frush and Fisher consider that 15% of the population falls within the vigorous type, 5% in the delicate one, the remaining 80% falling in between. Namely, due to the distribution of the majority of the population within the spectrum and not at its extremities allows one to have so much variability in terms of personality in the expressive zone.

Dale extended this spectrum, incorporating both sexes and completing the middle segment:

• Rugged vigorous
• Medium vigorous
• Moderately vigorous
• Active feminine
• Medium feminine
• Delicate feminine [3, 5, 12]

The masculine aspect is described by:

• The teeth are relatively larger in size
• Wider teeth
• Cuboidal shape
• The incisal edge (especially in lateral incisors) and the incisal angle are sharper and more angulated
• Smaller gingival embrasures [1, 5]

Feminine aspect:

• The teeth are relatively smaller in size
• Narrower teeth
• Rounded shape
• The incisal edge (especially in lateral incisors) and the incisal angle are rounded
• Larger embrasures [1, 5]

Vigorous aspect:

• Rough aspect
• Angulated edges and angles
• The crown of one central incisor is positioned anteriorly to its homologue
• The cervical third of one central incisor sits posteriorly, the other one- anteriorly
• Both central incisors are rotated in such a way that their distal surfaces come forward while the mesial ones go posteriorly
• The lateral incisors are rotated with their vestibular face facing forward
• The canines are rotated in such a way that the smile reveals 2/3 of their vestibular surface [2, 3, 5]

Delicate aspect:

• Rounded edges and angles
• The central incisors slightly overlap medially
• One of the central upper incisors has its cervical third positioned anteriorly or posteriorly, however the incisal edges remain at the same level
• The lateral incisors rotated with their mesial surface anteriorly
• The canines rotated in such a way that the smile reveals 1/3 of their vestibular surface [2, 3, 5]

Young aspect:

• The presence of mamelons on the incisal edge of the incisors
• The incisal edges are translucent and have a blue tint
• The central incisor is evidently longer than the lateral one
• The tooth colour has a lower saturation
• The canines have a sharper cuspid
• The gum is attached more incisally, younger teeth seeming shorter [3, 4, 5]

Aged aspect:

• Worn incisal edge
• The incisal edge of the central incisor is closer to the one of the lateral one
• The colour has a higher saturation
• The canine’s cuspid is worn off
• Gingival recession with elongated clinical crowns [3, 4, 5]

Rufenacht has updated the dentogenic concept and the SPA factor, introducing the SAP factor (Sexual Type, Aggressiveness and Personality). He omitted the “age” factor, arguing that the dental wear are not necessarily an expression of aging, it being prevalent in various age categories as an expression of certain dysfunctions of the stomatognathic system. Moreover, he criticizes the rigid tendency to adjust the dental morphology to the patient’s age, asserting that practitioners ignore the modern social trend of keeping a youthful look for as long as possible. Rufenacht goes on by saying that the desire to look younger is the main factor in an individual’s pursuit of beauty. As such, Rufenacht considers that the crown length should not be correlated with the age, it remaining constant for the entirety of one’s life. Furthermore, the “sex” factor is replaced by “sexual type”, in order to emphasize the absence of morphological differences related to sex. [10, 12] This change is upheld by a study conducted by Hottel T.L., in which the subjects were unable to accurately determine the sex of the owner of the dentures presented in photos. In fact, the odds ratio showed that one was 1.32 times more likely to perceive a denture as feminine than as masculine. [11]

Rufenacht considers that the central upper incuisor is “the most imoportant element of the dental composition in showcasing the individual’s personality”. It represents the objective criteria of the personality (energy, strength, magnetism, or rather apathy, submission). The lateral incisors comprise subjective, abstract criteria of the personality (artistic, emotional or intellectual elements). [10, 12]

The rational implementation of certain factors that describe the personality of the patient at the level of the dental composition, known as morphopsychology, could bring the practitioner closer to therapeutic success, stimulating a series of favourable psychological reactions at the perception of one’s own image, supported by the “dignity of being a unique individual”.

Materials and methods

The study implied the examination of eight subjects (3 men and 5 women) aged between 28 and 62 years, presenting signs and/or symptoms typical of aesthetic disharmonies of the dento-gingival composition of the frontal zone of the upper dental arch, following periodontal disease, partial edentations or dental anomalies.

The study was conducted within the clinical bases belonging to the Department of Therapeutic Stomatology and the Department of Prosthodontics “Ilarion Postolachi” of the State University of Medicine and Pharmacy “Nicolae Testemitanu”. 

The particularities of the clinical pictures within this “case study” were described based on the evaluation and analysis of the dento-facial, dental and gingival components of the smile in the light of the aesthetic principles described in scientific literature and some morphopsychological aspects that described the personality, age and sex of the subjects included in the stud

We should mention that these particularities also served as study inclusion criteria. Furthermore, we categorized the criteria into criteria attributed to the dento-facial composition, criteria attributed to the dento-gingival composition and dentogenic criteria.

The criteria of the dento-facial composition included: height of the upper lip, degree of upper frontal teeth display, smile symmetry, alignment of teeth according to the aesthetic guides of dental arch shape and lip position.

The dental criteria of the dento-gingival composition included: the shape, contour, texture, colour, position and axial tilt of the teeth.

The gingival criteria of the dento-gingival composition comprised the following: the incisal and gingival embrasures, gingival zenith, gingival aesthetic line (GAL) and some clinical aspects of the gum (contour, colour).

The dentogenic criteria of sex, personality and age that characterized the dental compositions included: the information systematized from the SPA concept introduced by Frush and Fisher, the personality spectrum introduced by Dale and the updated SPA factor introduced by Rufenacht.

In this context, the dentogenic criteria were evaluated and formulated through correlation with the shape, position and contour of the teeth making up the composition, in correspondence with the individual perception of the smile and the subject’s complaints.

The adjustment of inconsistencies and defects was carried out using the techniques of wax-up and mock-up, with the subsequent analysis of the composition’s design in order to facilitate the objectification.

The clinical evaluation of the occlusion was based on the determination and analysis of the centric relation and maximum intercuspation and their respective integration into the “occlusal model” in accordance to the provisions of the static and dynamic occlusal concepts described in scientific literature.

The obtained data was analysed according to the synthetic criteria of functional occlusion, with the subsequent planning and execution of occlusal therapy “per clinical case”.

In order to record the data related to the subjective perception of individual aesthetic aspects, while taking the anamnesis through the method of medical dialogue we have formulated certain sets of questions that concerned the self-evaluation of the smile design.

Another particularity of the clinical examination was the recording of data related to dento-facial and dento-gingival aesthetics in the subject’s files.

The psychological wellbeing of the subjects was evaluated pre- and post-treatment using the WHO-5 form.

In light of the aesthetic principles of proportion, symmetry, dominance, cohesive and segregating forces, we chose to carry out the evaluation by quantifying the dimensions of the tooth contours within the upper frontal dental composition with the aim of identifying the “critical aesthetic zones”, which will influence the harmonious visual perception of the composition’s elements and the selection of effective cosmeticisation procedures.

In this context, the radiographic examination was carried out as an ortopantomography (OPG X-Ray), using the KaVo KaVo ORTHOPANTOMOGRAPH™ OP3D Pro, using the Setting Nr. 5. The software used for measurements was CliniView Lite, version 3.1.1.

Based on the principles of radiotransparency and radiopacity characterizing the hard dental tissues (enamel, dentine), we have demarcated the interproximal zones of the components of the dental composition. Moreover, we have also drawn the reference aesthetic guides with continuous and discontinuous lines (median line, the bidimensional contour of the real vestibular face, the bidimensional contour of the apparent vestibular face, and the cervical lines of the gingival embrasures). The resulting image, which we titled “guide-schema” was created using Adobe Photoshop CC 2021, version 22.3.1.

The quantitative evaluation and analysis of the proportions of the contours of the elements from the upper frontal dental compositions was carried out for the “key-tooth” (the upper central incisor), applying the ideal width/length ratio of 4:5 (0.8:1), while admitting a variance of up to ±0.2 mm, and also applying the “golden ratio” (1.6:1:0.6) for the widths of the composition’s elements as stated by Lombardi and reiterated by Rufenacht.

This allowed us to identify the “critical aesthetic zones” of the dental composition using the aforementioned radiographic method.

We should mention that certain authors emphasize this method’s susceptibility to error (the thickness of the interproximal enamel), however it could be widely accessible as a “screening” method at the initial stages of the aesthetic diagnosing process.

In our opinion, if one is to compare the susceptibility to error in demarcating the interproximal enamel to the admitted variance of ±0.2 mm of the formulas dictating the harmony of proportions, one will notice that it does not significantly affect the accuracy of the cosmeticizing procedures.

From our point of view, the main advantage of this method of evaluation and analysis of the proportions of the bidimensional contours of the elements from the upper frontal dental composition is the possibility to identify the “guide 0” in the quantification process, i.e. the demarcation of the interproximal limits.

We do not exclude the possibility to complement the diagnosing process with computerized imaging methods using specialized software.

The identification of the “critical aesthetic zones” in the contour of the elements from the upper frontal dental composition through ordinary paraclinical methods allows one to delimitate the “apparent faces” and apply cosmeticizing procedures to create the “depth illusion” as the third dimension of the real plane.

In aesthetic dentistry, this creates premises for the replication of shadows through the manipulation of colour, the positioning and recontouring of the teeth.

The classic colour analysis to reproduce the individual colour characteristics of the teeth (saturation, luminance, translucence, opalescence, etc.) was carried out in two stages: gross and fine analysis.

This method was based on the visual comparison between the tooth’s colour and the standardized reference on the colour guides: Vitapan Classical for composite resin restorations and Vitapan Lumin Vacuum for ceramic restorations.

Consequently, we have determined the hue, saturation and luminance while respecting the rules stipulated in scientific literature (10 basic rules).

In order to obtain better aesthetic performance, after the colour analysis we have sketched and analysed a manual “colour map”.

Following the chromatic analysis and analysis of the the “colour map”, photographs from various angles were taken to highlight the characteristics of the teeth from the composition through the method of digital photography. In this regard, we have used the high resolution DSLR Nikon D3200, equipped with a AF-S NIKKOR 50mm f/1.8G lens.

In this context, certain technical requirements described in scientific literature were respected, in order to get a clear picture of the subject’s aesthetic status (positioning, drying out moisture, background, avoiding tilt, etc.).

In situations when it was difficult to determine the tooth’s colour through the classic method, it was complemented with the digital method using the camera.

The diagnostic dental casts were analyzed separately, in maximum intercuspation and centric relation, the limit movements were analyzed in the adjustable articulator Reference.

When necessary, we conducted the biometric analysis of teeth and their position within the composition and then we extrapolated them with dentistry’s aesthetic principles.

The aesthetic quantification process was carried out in correlation with the occlusal parameters (overbite, overjet, the depth of Spee’s curve, the direction and level of the occlusal plane, etc.).

The esthetic therapeutic objectives formulated following the clinical and paraclinical evaluation and analysis influenced the planning and selection of restorative methods (direct, indirect, mixed) in the treatment of the upper frontal dental compositions.

Final results and discussions

The subjects included in the study lot presented signs and/or symptoms characteristic of esthetic disharmonies of the upper frontal dento-gingival compositions, following periodontal disease, partial edentations or dental anomalies.

The results obtained from the evaluation and analysis of the dento-facial components of the smile permitted us to attribute the following qualifiers: attractive/unattractive; pleasant/unpleasant.

The degree of tooth display was appreciated individually, based on the gingivo-incisal height of the upper frontal teeth, the height of the upper lip and the visual tolerance of the subjects. (see fig. 5)

Concomitantly, following the clinical evaluation and analysis of occlusal parameters, the diagnosis of “point centric” and “freedom in centric” was made. It made possible to make an individual selection, for each subject, of the reference position (centric relation, habitual occlusion, maximum intercuspation), which then served as therapeutic positions in the occlusal reconstructions/restorations.

We have selected the clinical situations that presented therapeutic positions of habitual occlusion or maximum intercuspation at an optimal vertical dimension of occlusion, a stable overjet and overbite, where the intermaxillary relations were conserved with minimally invasive occlusal remedial. The therapeutic algorithm of occlusal remedial consisted of the following: the liquidation of premature occlusal contacts in centric relation-habitual occlusion; static equalization through selective grinding of the occlusal contacts according to the scheme (habitual occlusion = maximum intercuspation); the liquidation of occlusal interferences, while respecting the provisions of the global concept of mutually protected occlusion.

We should mention that at the basis of the minimally invasive occlusal remedial through techniques of occlusal equilibration, stood the “rule of thirds”, marking the occlusal contacts with articulating paper in two colours.

It goes without saying that the health status of the stomatognathic system, especially the temporo-mandibular joint and the masticatory muscles was taken into account. In this context, the long lasting lack of musculo-articular discomfort, the lack of alterations in the objective clinical exam, even with the presence of chronic occlusal disharmonies, has confirmed the selection of this therapeutic algorithm of occlusal remodeling.

The therapeutic consensus of conserving the occlusal parameters (overjet, overbite) in the selected therapeutic position as well as the aesthetic dento-facial parameters of gingivo-incisal height of upper frontal teeth and their degree of display relative to the height of the upper lip was the first step in the process of diagnosis and occlusal remedial.

We should mention that the data was written down in the medical records with the patient’s consent, which was an important first criterion in the assessment of the individual visual tolerance in the perception of the dento-facial compositions.

The results of the clinical evaluation and analysis of the dento-gingival components of the smile made it possible to identify the “critical aesthetic zones” among the composition elements following the changes in tooth position and the parameters of the dento-gingival contour (dental width/height; cervico-papillar space). (see fig. 6)

Concomitantly, we have also evaluated and analysed the dentogenic criteria of sex, personality and age of the upper frontal dental compositions according to the reasoning proposed by us and depending on the individual perception of the “smile’s expressiveness”. Initially, we identified the contour, shape and position nonconformities of the teeth on the photos and diagnostic casts of the subjects. This data was analysed in light of the sex, personality and age of the patient, being later registered in the medical record of the subjects. This represents the next criterion in the assessment of individual visual tolerance of the dental compositions.

In order to facilitate the “quantification of aesthetic parameters”, conventional imaging techniques were used due to their accessibility, simplicity of diagnosis and possibility to highlight the “critical aesthetic zones”, as well as in the regular initial planning of the cosmeticisation sequences.

For the objectification and visualization of the ideas outlined above, the wax-up and mock-up techniques were employed.

The change in the dento-gingival composition design following the liquidation of nonconformities and /or the illusory aesthetic perception of contour “critical aesthetic zones” of the compositional elements, was visualized together with the subjects and either accepted or unaccepted, which was the next criterion in the assessment of individual visual tolerance.

Concomitantly, together with the subjects, the shape and arrangement of the compositional elements were visualized in order to highlight the smile’s expressiveness.

A chromatic map of the “dental composition” was made for each individual subject.

The most important step was the demarcation of transition areas in the “critical aesthetic zones” with the nominalization of the final colour hue for the “apparent faces” and the “transition areas”, based on the concepts of “opacity” and “translucency”.

The schematizations served as reference guides for cosmeticisation during the stages of restorative treatment of the upper dental arches.

Through complex therapeutic procedures of occlusal equilibration, recontouring of compositional elements and guided layering in dental restorations, one can simultaneously achieve occlusal and aesthetic therapeutic objectives.

The cosmeticisation of dental compositions with the application of illusory artifices increase the degree of tolerance of the subject’s aesthetic visual perception.

Conclusions:

1. Following the analysis and synthesis of scientific literature, we have systematized the smile evaluation criteria into: criteria of the dento-facial composition; criteria of the dento-gingival composition and dentogenic criteria.
2. Following the application of the proposed evaluation and analysis method, one could identify the “critical aesthetic zones” of aesthetic perception within the dento-facial and dento-gingival compositions.
3. During the process of staged planning of bioaesthetic sequences, the distinction and compromise in the quantification of aesthetic and occlusal parameters was made.

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