Determinants Factors for the Choice of the Width Prosthetic Upper Central Incisor: Review of the Literature

Materials and Methods: The authors conducted a review of the literature around the theme, determinants of the choice of the width of the upper central incisor (WUCI), through search web including Pub Med, Inari and Google. Fifteen of the most recent publications since 2005 have been selected from twenty publications. Sample size (n), age range (AR), average bi zygo-matic distance (BZD), choice determinants, type of study, and mathematical formula between WUCI and BZD were the study’s interest variables. Sociodemographic characteristics, facial anatomical marks and the size of the patient’s teeth for anterosuperior were the main factors to be assessed. Results: Out of 22 included articles, the Asian continent represents 59% in which India is the leading country with 27.3% followed by American 22.8%. The most Determinants choice for the width upper central incisor in craniofacial and anterior teeth method from the published papers were BZD (100%; n = 22) and WUCI (81.8%; n = 18). Conclusion: Application of mathematical formulation maybe help to predict the exact width of the upper central incisor.


Introduction
The success or failure of prosthetic treatment depends in great part on the step of choosing the upper anterior teeth dimension [1]. The latter requires careful reflection and the arithmetic calculations of the practitioner [2]. On the other hand, it might need during the consultation; a series of anatomical constitutive unit or sociodemographic of the patient such as the shape of the face and nose, the color of the patient's eyes, hair and skin, sex, personality and age [3]; as well as the ethnicity, race, region, continents, weight, etc. All of these factors maybe make the choice of the width of the top six anterior teeth (W6AT) or the upper central incisor (UCI) not only difficult [4], but also very complex. In addition, the genetic, hormonal, environmental, climatic, social and food factors of each individual as well as the customs of the population; may influence the craniofacial and dental dimension, especially in children population [5] [6]. In 1996, Hillson demonstrated in England that dietary factors could affect musculature and swallowing [7]. Antero-superior teeth are the key elements that contribute to the importance of aesthetic and beauty of dental facial [8]. It remain overrun the second position after the eyes in the appearance of the face [9]. The Upper Central Incisor (UCI) is considered as the star of all teeth; the most desired, cited and the most studied in relation to other teeth [10]. It is the most aesthetically pleasing tooth in the previous sector for its visibility in the mouth [11] [12].
In the case of complete edentulous in adulthood, especially in the absence of pre-extraction documents, the practitioner is called upon to make a judicious choice of one or whatever facial mark, and a series of aforementioned factors maybe help to determine either the width of an upper central incisor or the group of anterior teeth. To the best of our knowledge, no studies have been conducted in the Democratic Republic of Congo (RD Congo) about the determinants factors of choice of the width prosthetic upper central incisor. The aim of the study was to make an inventory of published articles about the determinants factors of choice for prosthetic WUCI in order to foresee the mathematical formulation between the WUCI and the BZD among the Congolese.

Materials and Methods
A review of the literature was performed in June 2020 using MEDLINE, PubMed, Scopus, Inari and Google. Keywords included the following terms: determinants, choice, width, upper central incisive, complete tooth. We selected the most recent articles of interest from 2005 to 2019. Reference lists of all articles retrieved from databases search were also selected for further relevant studies. Abstracts were reviewed and relevant articles were given more attention, and if possible, reviewed in full. Prospective or retrospective clinical studies, with a sample size of n ≥ five, in which the main focus was on data regarding age range, BZD average, WUCI selection determinants factors, and mathematical formula used between WUCI and BZD were evaluated and included in this review. Exclusion criteria were studies with unclear reporting of the aforementioned variables, nonhuman studies, letters, preface and comments. After the full

Results
Out of 22 included articles, the Asian continent represents 59% in which India is the leading country with 27.3% followed by American 22.8% (Table 1). The most Determinants choice for the width upper central incisor in craniofacial method from the published papers were BZD (100%; n = 22) followed by ICOD (30%; n = 7) and WUCI (81.8%; n = 18) followed by ICCD (18.2%; n = 4) for anterior teeth method ( Table 2). The average BZD is variable according to gender, race and ethnicity (Table 3).

Comments
The  [13]. However, typology is a support factor for age and sex. They affect the aesthetics and designates the smile [13]. However, typology is a support factor for age and sex that helps to create a pleasant-looking tooth [14].    [19] [20]. However, many authors advocate the combination of these facial parameters in determining the choice of width of the anterior teeth [19] [20] [21].
The average BZD is variable according to gender [22] [23] [8], race [24] and ethnicity [25] [26]. The bizygomatic width among Europeans appears to be smaller compared to that of Africans and Asians. The formula between BZD and WUCI is always obtained in proportion form. This ratio is equal to 1/16 in several Asian and European countries [11] [27] [28]. However, this proportion is less than 1/16 in Africa [1] [29]; but also more than 1/16 in some countries.

Conclusion
Demographic, craniofacial and dental determinants of toothed subjects can lead

Conflicts of Interest
The authors declare no conflicts of interest regarding the publication of this paper.