Visible Teeth Research Articles

Effectiveness of Papain-Based Organic Dentifrices Versus Commercial Whitening Dentifrice on Tea-Induced Tooth Stains: An In Vitro Study.

Tooth discoloration is a common issue for oral health practitioners. Whitening treatments remove surface and deep stainsusing either chemicals or over-the-counter products. Due to harmful chemical effects, organic whitening products are increasingly preferred. This study compared the effectiveness of organic papain-based dentifrices (Perfora Magic Teeth Whitening Serum, Gurugram, India) on tea stains to commercially available Colgate whitening dentifrices (Colgate-Palmolive, New York, NY). Sixty maxillary central incisors for periodontal reasons were used and divided into two groups. Each sample was soaked in freshly brewed tea for 10 minutes daily and stored in artificial saliva (Nanochemazone, Kurukshetra, India) for 24 hours. After four weeks, group 1 was treated with papain-based dentifrices, and group 2 with Colgate Visible White teeth whitening paste(CVWP) daily for four weeks. Spectrophotometric analysis (VITA Easyshade V, VITA Zahnfabrik, Bad Säckingen, Germany) was performed pre-treatment and at four weeks post-treatment. Data were compiled and statistically analyzed. Compared with group 1, group 2 exhibited an optimal color change (ΔE). Statistically significant differences were observed between the mean ΔL (lightness) and Δb (blueness -b or yellowness +b) values. CVWP showed better color achievement and stain reduction due to abrasive and peroxide components. Although Perfora Teeth Whitening Serum has low efficacy in upgrading the color of the enamel surface, it is safe for long-term use.

Three-dimensional analysis of posttreatment tooth movements despite bonded retainers: partI-upper jaw.

Adverse side effects of fixed retainers in terms of unwanted tooth movements have been described for both the upper and lower jaw, but data about the extent and movement patterns for the maxilla are scarce. The purpose of the present retrospective case-control study was to analyze the amount and direction of unwanted tooth movements despite upper bonded retainers as well as to analyze possible predisposing pretreatment- and treatment-related factors. Plaster casts of 1026 patients who completed orthodontic treatment and asubsequent retention phase of 2years were screened for unintentional tooth movements. The study group comprised 57patients with visually obvious tooth movements in the upper jaw, while 57randomly selected patients without visible tooth movements served as control group. For all patients, plaster casts after debonding of multibracket appliance (T1) and after supervised retention (T2) were digitized, and superimposed digitally using astable palatal reference area. Thereafter, translational and rotational movements were measured in all three planes of space. Pretreatment- and treatment-related factors of the study and control groups were compared by χ2 test, exact Fisher test, Mann-Whitney U test, and the T‑test for independent samples. The mean translational movements ranged between 0 and 0.6 mm and the average rotational movements between 0 and 1.3°. Large individual movements up to 2.7 mm translation and 15.9° rotation were seen. Amovement pattern around the Y‑ and Z‑axis with an opposite rotational peak at the canines ("upper twist effect") was identified. Compared to the control group, patients of the study group showed asignificantly smaller intercanine width pretreatment. Also, study group patients presented alarger intercanine expansion and aslightly larger overjet reduction during treatment, and were more often affected by retainer bonding site detachments and wire fractures, but without reaching statistically significance. Upper bonded retainers show asimilar unwanted movement pattern ("twist effect") like the one described for mandibular retainers.

Three-dimensional analysis of posttreatment tooth movements despite bonded retainers: partII-lower jaw.

Complications of bonded lingual retainers in terms of unexpected tooth movements have been reported with increasing frequency during the last decade, but the vast majority of the literature comprises case reports. The purpose of the present retrospective case-control study was to analyze the amount and direction of unwanted tooth movements despite lower bonded retainers, to analyze possible predisposing pretreatment- and treatment-related factors, and to seek for movement thresholds which could enhance the rapid and objective identification of critical cases. Plaster casts of 1026 patients who completed orthodontic treatment and asubsequent retention phase of 2years were screened for unintentional tooth movements. The study group comprised 39patients with tooth movements in the lower jaw, while 39randomly selected patients without visible tooth movements served as the control group. For all patients, plaster casts after debonding of multibracket appliances (T1) and after supervised retention (T2) were digitized, and athree-dimensional (3D) digital superimposition based on the best fit of premolars and molars was undertaken. Thereafter, translational as well as rotational movements were measured in all three planes of space. Pretreatment- and treatment-related factors of the study and control groups were compared. Aseverity classification based on rotational movement thresholds was applied to seek acritical amount of translational movements. The mean translational movements ranged between 0 and 0.4 mm and the average rotational movements between 0 and 1.6°. Large individual movements up to 1.9 mm translation and 16° rotation were seen. Atwist-effect with opposite movements of the canines along the Y‑axis could be confirmed. Compared to the control group, patients of the study group had asmaller intercanine distance at all timepoints. In addition, study group patients presented aslightly larger intercanine expansion during treatment and were more often affected by retainer bonding site detachments. Applying the severity classification based on rotational thresholds, translational movements of 0.5-1.0 mm along the X‑ and Y‑axis could serve as acritical threshold. It can be assumed that extrusive translational movements along the Z‑axis seem to be of specific nature and perhaps do not reflect aretainer complication in terms of unwanted tooth movements. Patients with alarger intercanine distance after active treatment and those with more frequent retainer bonding site detachments could be at higher risk for unwanted tooth movements during fixed retention. Sagittal and transverse movements of 0.5-1.0 mm should sensitize the practitioner for further measures.

Chronic oral disease burden at the first 1000 days: Intergenerational risk factors, BRISA cohort

AbstractObjectiveTo analyze multiple‐causal models, including socioeconomic, obesity, sugar consumption, alcohol smoking, caries, and periodontitis variables in pregnant women with early sugar exposure, obesity, and the Chronic Oral Disease Burden in their offspring around the first 1000 days of life.MethodsThe BRISA cohort study, Brazil, had two assessments: at the 22nd–25th gestational weeks and during the child's second year (n = 1141). We proposed a theoretical model exploring the association between socioeconomic and pregnancy factors (age, smoking, alcohol, sugars, obesity, periodontitis, and caries) and child's variables (sugars and overweight) with the outcome, Chronic Oral Disease Burden (latent variable deduced from visible plaque, gingivitis, and tooth decay), using structural equation modeling.ResultsCaries and periodontitis were correlated in pregnant women. Addictive behaviors in the gestational period were correlated. Obesity (Standardized coefficient ‐ SC = 0.081; p = 0.047) and added sugar consumption (SC = 0.142; p = 0.041) were observed intergenerationally in the pregnant woman‐child dyads. Sugar consumption by the children (SC = 0.210; p = 0.041) increased the Chronic Oral Disease Burden.ConclusionsPoor caries and periodontal indicators were correlated in pregnant women and their offspring. Obesity and sugar consumption act intergenerationally. Oral health in early life may change life trajectory since the worst oral conditions predict main NCDs.

A Comparative Analysis of the Effect of Individualistic, Unique Hard- and Soft-tissue Parameters of the Face on Buccal Corridors in Adolescents and Adults with Angle’s Class I and Angle’s Class II Division 1 Malocclusion

Background and Objectives: This study was designed to determine the relationship between the parameters: buccal corridor, buccal corridor linear ratio (BCLR), upper intercanine width, intermolar width, and premolar basal arch width on a posed smile in adolescents and adults. The buccal corridor affects smile esthetics; hence, it is important to see its correlation with intercanine width. In addition, the study aimed to determine if the buccal corridor changes adversely in Class I and Class II Division 1 malocclusion patients and during growth. Materials and Methods: Posed smile and standard full-front face photographs of 150 patients were taken. Group A consisted of 50 adolescent patients between the ages of 11 and 14 years, divided equally based on malocclusion type. Group B consisted of 100 young adults between the ages of 18 and 25 years, divided equally into Class I and Class II Division 1 malocclusion. The parameters calibrated in the photographs were: upper intercanine distance, intercanthal distance, intercommisure width, difference between intercanthal and intercommisure width, distance between the last visible teeth in the maxilla, and BCLR. Results: The results of this study were analyzed using one-way ANOVA and Chi-square tests. The analysis showed a significant correlation between BCLR, intercanine width, distance from the last visible teeth, intercanthal distance, and intercommisure width, and their difference varied significantly among males and females, with P < 0.05. Conclusion: This study concluded that the buccal corridor and intercanine width vary with age and gender. The buccal corridor is usually wider in young adults than in adolescent children.

The Psychological Effects of a Perfect Smile on Adults: A Survey

Purpose: To investigate the psychological impact of dental aesthetics, specifically the effect of a perfect smile, on adults.
 Methodology: A random cross-sectional research was conducted on 200 adult patients who attended the dentistry facilities at Riyadh Elm University. To determine patient satisfaction with their overall dental look, an online questionnaire will be used. This cross-sectional research included REU patients and dentistry students. Adults over the age of 18 were all included in the study.
 Findings: On visible teeth numbers majority selected the second option, on the buccal corridor was option 2 and 3 equally, on smile lip line was first while on lower lip touching again was 2 and 3r equally. The majority of them never had any problem because of mouth or teeth in word pronunciations, in the sense of taste. However, the majority have painful aching in the mouth occasionally. The majority of participants never felt embarrassed and irritable because of any teeth problem. The majority of participants never had difficulty in their usual job doing, less satisfy and unable to function because of any teeth problem.
 Unique Contribution to Theory, Policy and Practice: The paper provides unique insights into the psychological impact of a perfect smile on adults, highlighting its role in enhancing self-esteem and quality of life. It suggests that aesthetic dentistry is not just about physical health but also mental well-being. These findings can guide policy development and practice in dentistry, emphasizing holistic patient care.

Aesthetic Treatment Needs for Buccally Displaced Canines in Orthodontics

Background and Objectives: Aesthetic and related psychosocial impairment are the major ill effects of malocclusion. Many studieshave concluded that aesthetics, especially alignment of the visible anterior teeth, is often a main motivating factor for see kingorthodontic treatment. The objective of the study was to assess the aesthetic treatment need of orthodontic patients with buccallydisplaced maxillary canines using the “Aesthetic Component of Index of Orthodontic Treatment Need (AC-IOTN)”.Methodology: We recruited 158 subjects at Khyber College of Dentistry (KCD), with a chronological age range of 12 to 30 years.Age, gender, aesthetic grade and category of treatment need were noted for all the patients. Version 20.0 of the Statistical Packagefor Social Sciences was used to enter and analyze the data.Results: Our sample consisted of 71 (44.9%) males and 87 (55.1%) females. The mean age of the overall sample was 18.51± 4.2years. There were 82 (51.9%) patients in the “no or little need” category, 25 (15.8%) patients in the “mod erate” treatment needcategory, and 51 (32.8%) patients in the “definite” treatment need category, where most of the patients had a grade 8 need on IOTNAC.Conclusion: On aesthetic need, majority of patients in definite treatment need category fell in the grade 8. Therefore it can beconcluded that buccally displaced canine is one of the primary motivating factors for people to seek orthodontic treatment.

Effect of smile esthetics on the quality of life in a Han Chinese population.

This study aimed to explore the influence of smile esthetics on the quality of life in a Han Chinese population. A total of 110 Han Chinese volunteers (52 males and 58 females, mean age 26.7 years) were recruited, and frontal images of their smiles were collected. A photoediting program was used to evaluate the following components of smile esthetics: the buccal corridor ratios, the angle between the interpupillary and commissural lines, the number of visible teeth, and width-to-length ratios of the maxillary central incisors. Oral health-related quality of life (OHRQoL) in these volunteers was evaluated using the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile-14 (OHIP-14). Statistical analyses were performed by using Pearson's correlations and multiple linear regression (α=0.05). Compared to males, females scored higher on psychological impact (p=0.017). Moreover, the number of visible teeth had a significant effect on social impact, psychological impact and esthetic concern (all p < 0.05). However, the buccal corridor ratios, the angle between the interpupillary and commissural lines, and the width-to-length ratios of the maxillary central incisor did not correlate with the OHRQoL (all p > 0.05). The number of visible teeth significantly influenced the quality of life in a Han Chinese population. Smile esthetics had a significantly greater psychological impact on females than males. This study highlights the effects of smile esthetics on the quality of life in a Han Chinese population. Female patients may raise more esthetic concerns in clinical practice.

Facial indicator in the determination of maxillary central incisor length in Nepalese population – A clinical study

Background: The maxillary anterior teeth are important in achieving pleasing facial and dental esthetics. Among those, the central incisor has a key role in determining the esthetic as they are the most dominant and visible teeth during smile. Determining the proper size of these teeth is important but difficult in the absence of pre extraction records in edentulous condition. Aims and Objectives: This study was conducted to find a suitable guide in determining the length of the central incisor by correlating it with some independent facial structure like nose length in a small population of Chitwan district. Materials and Methods: The distance from the bridge of the nose to the base was compared to the length of the maxillary central incisor in 321 patients of both sexes between the age groups of 20–35 years. The actual length of the maxillary incisor was measured and also calculated by regression analysis to determine some fixed ratio. The calculated value by this ratio was compared to the actual measured value to find if the difference was significant. Results: The difference between the calculated distances and the actual measured distance was found to be 0.340 in males and 0.266 in females, which was statistically significant (P&lt;0.001). Conclusion: The distance from the bridge of the nose to base of the nose may be used as a reference to estimate the length of the central incisor in the Nepalese population, although sample included subjects from the central Chitwan District of Nepal.

Bone-cutting instruments.

In 1837, a French surgeon observed that, under a microscope, fine scalpel blades have a serrated appearance (as do all knife blades). To divide tough cortical bone, however, strong force (delivered manually or mechanically) requires saws made of steel sheets with visible serrations or teeth. These latter may be offset individually, alternative teeth being slightly angled away from each other to create a grooved incision in the wet bone. This broader incision helped prevent the saw jamming. Often pushing the saw more strongly than equal pull-and-push allowed more careful and controlled bone division. In previous times, the strong manual measured to-and-fro movement has been supplanted by a safer oscillating power-driven cut using smaller blades. Care had to taken not to damage soft tissue and to obtain a clean excision, with little or no splintering of bone ends. Before the advent of anaesthesia, the sawing of a limb bone was reputedly one of the most painful and challenging experiences of an amputation. Saw blades became jammed between the bone ends or jerked the limb painfully with rough handling. Before the introduction of these modern instruments and over time, the tenon saw with a reinforced steel strip along its back proved more robust than bow or frame saws, whose thin blades frequently snapped (Fig. 1).

Evaluation of parameters related with upper lip aesthetics and dynamic smile following Le Fort I osteotomy

ObjectiveThe present study aimed to investigate how upper lip aesthetic and dynamic smile parameters are changed following a Le Fort I osteotomy. MethodsTwenty-seven patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Upper lip aesthetic parameters which were Cupid's bow angle, lip angle, lip length, lip width, philtrum width and lip corners were evaluated on pre and postoperative rest photos using Image J software. Lip corner movement direction, buccal corridor area with respect to canine and last visible tooth were also measured on posed smile photos with respect to dynamic smile evaluations. Measured variables were submitted to statistical analysis and significance level was determined as 0.05. ResultsThere was a significant reduction in buccal corridor area according to last visible teeth for right and left side at postoperative period. However, buccal corridor area with respect to canine for the right and left side was not significant. The angle between the lip corner movement direction and Y-axis of the face for the right and left sides was not significant between pre and postoperative period. The changes in this angle were not also correlated with the changes in buccal corridor area and maxillomandibular movements. Not only the Cupid's bow angle, lip angle but also lip length, lip width, philtrum width and lip corner have not been changed significantly. ConclusionBuccal corridor area investigated in dynamic smile shows significant improvement after orthognathic surgery especially in the means of maxillary impaction. Lip corner movement during smile was not associated with the changes in buccal corridor area. Landmarks around perioral area in static state were affected clinically with no statistical significance following the surgery.

Assessment of public awareness and satisfaction toward the hollywood smile in Saudi Arabia: a cross-sectional study

Background: Hollywood smile refers to a complete prosthetic reconstruction of both jaws or at least all visible teeth using crowns, veneers, and, quite often, implants. Such a name has been selected since Hollywood actors and celebrities widely use it. Fixed exposure to the celebrity&amp;apos;s personal life has a significant impact on people&amp;apos;s choice of dental treatments, exclusively dental esthetics, for example, the Hollywood smile. This study aims to measure public awareness and knowledge about the Hollywood smile and to assess the satisfaction of those who have it. Methods: In this cross-sectional study, 384 pre-designed, pre-tested, and self-administered Arabic questionnaires were distributed to the participants through social media platforms. The inclusion criteria were both genders, Saudi citizens aged 18-60 years old, mentally sound, who use social media and have a Hollywood smile, or who are thinking and planning to receive a Hollywood smile. The collected data were analyzed using Statistical Package for the Social Sciences software. Results: The total mean score for knowledge was 13.22 ± 4.26 (moderate level) for 21 Hollywood smile knowledge questions. The participants&amp;apos; knowledge significantly differed concerning gender, occupation, and level of education. Only 4.43% of participants had a Hollywood smile, with 76.47% of satisfaction. There was no significant difference in knowledge between satisfied and non-satisfied about the Hollywood smile (p &amp;gt; 0.05). Conclusion: The overall knowledge of Hollywood smile was moderate and needed improvement. The study found only 4.43% of participants to be having Hollywood smiles. Further studies are needed to assess the satisfaction further.

Five new species of freshwater crabs of the genera Ghatiana Pati &amp; Sharma, 2014 and Sahyadriana Pati &amp; Thackeray, 2018 from India (Decapoda: Brachyura: Gecarcinucidae)

We recognize two new species of Ghatiana Pati & Sharma, 2014, and three new species of Sahyadriana Pati & Thackeray, 2018, from the Western Ghats of India. Ghatiana durrelli n. sp. is characterized mainly by the proportionately narrower adult carapace, the relatively broader male pleonal somite 6, and the relatively stouter terminal segment of the male first gonopod. Ghatiana rouxi n. sp. is differentiated from congeners by its proportionately narrower adult carapace with the gently convex lateral margins. Sahyadriana inopinata n. sp. is characterized by a suite of characters that includes the visible epibranchial tooth, the relatively slenderer and longer terminal segment of the male first gonopod, and the subovate and relatively smaller adult vulva that is positioned a clear distance from the suture between thoracic sternites 5 and 6. Sahyadriana keshari n. sp. differs from the allied S. waghi (Pati in Pati, Thackeray & Khaire, 2016) by the relatively stouter terminal segment of the male first gonopod, and the relatively larger adult vulva, which is positioned close to the suture between thoracic sternites 5 and 6. Sahyadriana tamhini n. sp. most resembles S. alcocki (Pati in Pati, Thackeray & Khaire, 2016) but can be differentiated by its relatively longer, distally distinctly narrow terminal segment and the sinuous inner margin of the subterminal segment of the male first gonopod, and the relatively closely positioned and larger adult vulvae. Ghatiana and Sahyadriana now include 10 species and 13 species, respectively. An updated key is provided for both genera.

Perceptions of orthodontists, laypersons, and patients regarding buccal corridors and facial types

The space on each side of the mouth, between the commissure of the mouth and the buccal surface of the last visible tooth, is called the buccal corridor. The size of the buccal corridor can affect perceptions of facial esthetics. We analyzed the perceptions of orthodontists, laypersons, and orthodontic patients regarding the size of buccal corridors in people with brachyfacial, mesofacial, and dolichofacial types. Photographs of 1 male and 1 female model were modified digitally into brachyfacial, mesofacial, and dolichofacial types. Each facial type was further modified to create 5 sizes of buccal corridors. Orthodontists, adult orthodontic patients, and laypersons were invited to rate the photographs. Orthodontists rated lower than the other groups of raters when they evaluated the female model with the buccal corridors of 20% (P<0.05). Laypersons could not distinguish the changes of the buccal corridors when evaluating the male model with brachyfacial and mesofacial (P>0.05). Orthodontic patients rated significantly higher than the orthodontists and the laypersons when evaluating the dolichofacial type of both models (P<0.05). Orthodontists are more sensitive to the buccal corridors than are orthodontic patients and laypersons. It is only necessary to consider eliminating the patient's buccal corridors when the buccal corridor area ratio is over 15%.

Weekly and Daily Tooth Brushing by Care Staff Reduces Gingivitis and Calculus in Racing Greyhounds.

Simple SummaryDental disease affects many dogs worldwide and is believed to be particularly problematic for racing greyhounds. It costs the industry and rehoming charities financially and likely causes unnecessary suffering to a large number of dogs. The risk factors for dental disease in this population are debated, and the best methods to overcome it are relatively unresearched. We carried out a trial in which 160 racing greyhounds were divided into three groups. The staff looking after them either brushed their teeth daily, weekly or never, for a period of two months. An experimenter measured the dog’s level of calculus (hardened dental plaque) and gingivitis (gum inflammation) at the start, and again after two months. We found that both weekly and daily brushing resulted in significant reductions in calculus, but for gingivitis only daily brushing resulted in a significant reduction. The effects, however, were not noticeable on the front incisor teeth. Since the staff implementing the routine reported a minimal time commitment and positive experiences, we suggest that daily brushing is recommended for racing greyhounds, and that emphasis is placed on brushing all teeth groups. Similar trials need to be conducted with retired greyhounds since these have been shown to present particularly high levels of periodontal disease. Periodontal disease is one of the most common conditions affecting dogs worldwide and is reported to be particularly prevalent in racing greyhounds. A range of potential risk factors have been hypothesised. Previous research has suggested that regular tooth brushing can reduce both calculus and gingivitis, but the frequency required is unclear. Here, we report a controlled blinded in situ trial, in which kennel staff brushed 160 racing greyhounds’ teeth (living at six kennel establishments), either weekly, daily or never over a two-month period. All of the visible teeth were scored for calculus and gingivitis, using previously validated scales. We calculated average scores for each of the three teeth groups and overall whole mouth scores, averaging the teeth groups. Changes were compared to the baseline. After two months, the total calculus scores (controlling for baseline) were significantly different in the three treatment groups, (F(2,129) = 10.76, p < 0.001) with both weekly and daily brushing resulting in significant reductions. Gingivitis was also significantly different between groups (F(2,128) = 4.57, p = 0.012), but in this case, only daily brushing resulted in a significant reduction. Although the dogs in different kennels varied significantly in their levels of both calculus (F(5,129) = 8.64, p < 0.001) and gingivitis (F(5,128) = 3.51 p = 0.005), the intervention was similarly effective in all of the establishments. The teeth groups varied, and the incisors were not significantly affected by the treatment. Since the trainers implementing the routine, reported a minimal time commitment and positive experiences, we suggest that daily brushing is recommended for racing greyhounds, and that any instructions or demonstrations should include attention to all teeth groups including the incisors. Similar trials need to be conducted with retired greyhounds since these have been shown to present particularly high levels of periodontal disease.

Beyond Smiles: Static Expressions in Maxillary Protrusion and Associated Positivity.

Smiles play an important role in social perception. However, it is unclear whether a similar role is played by static facial features associated with smiles (e.g., stretched mouth and visible teeth). In dental science, maxillary dental protrusions increase the baring of the teeth and thus produce partial facial features of a smile even when the individual is not choosing to smile, whereas mandibular dental protrusions do not. We conducted three experiments to assess whether individuals ascribe positive evaluations to these facial features, which are not genuine emotional expressions. In Experiment 1, participants viewed facial photographs of maxillary and mandibular protrusions and indicated the smiling and emotional status of the faces. The results showed that, while no difference was observed in participants’ perception of the presence of a smile across both types of dental protrusion, participants felt more positive to faces with maxillary than mandibular protrusions. In Experiment 2, participants completed an Implicit Association Test (IAT) test measuring implicit attitudes toward faces with maxillary vs. mandibular protrusions. The results showed that participants had more positive attitude toward faces with maxillary than mandibular protrusions. In Experiment 3, individuals with either maxillary or mandibular protrusions completed the same IAT test to assess whether any preference would be affected by in-group/out-group preferences. The results showed both groups had more positive attitudes toward faces with maxillary protrusion, indicating that this preference is independent of the group effect. These findings suggest that facial features associated with smiles are viewed positively in social situations. We discuss this in terms of the social-function account.

Accidental intraosseous displacement of mandibular premolar root during extraction with guidance and literature review

ABSTRACTIntroductionIatrogenic displacement of teeth during extraction is a rare complication, commonly associated with third permanent molars and their displacement into fascial spaces. We wish to raise awareness of intraosseous tooth displacement as a potential risk of routine exodontia with possible serious consequences. The prevention and management of displaced teeth are discussed. We present a rare case of apical, intraosseous displacement of a mandibular premolar root during attempted extraction; resulting in paraesthesia.Presentation of CaseA 30‐year‐old woman was referred to the Oral and Maxillofacial department with paraesthesia to the left lower lip, chin and anterior gingivae following a failed extraction of the lower left second premolar tooth (LL5) by her general dental practitioner. Intra‐oral examination showed no visible tooth at the extraction site, but an orthopantogram (OPG) and Computed Tomography (CT) mandible confirmed apical, horizontal and intraosseous displacement of the retained LL5 root which was in close proximity to the inferior dental nerve, and inferior to the LL6. Surgical intervention was required and involved raising a mucoperiosteal flap, buccal bone removal and root retrieval through the bony window. Post‐operatively, the surgical site healed uneventfully, however, there was persistent paraesthesia.ConclusionOn literature search, this is the first reported intraosseous displacement of a mandibular premolar during dental extraction.This case highlights the importance of safe extraction techniques. Care must be taken to ensure controlled force and correct positioning of instruments to minimise such complications.

The impact of visible dental decay on social judgements: comparison of the effects of location and extent of lesion

Previous research has established that people can make social judgements about someone else based on the condition of that person's teeth. The characteristics of visible tooth decay, with respect to the effect on such social judgements, have not, however, been subject to extensive investigation. This study sought to determine whether the position of visible decay and/or the extent of the lesion are determining factors in such social judgements of each other. In a between subjects design, 100 young people were randomly divided into 4 groups of 25 and each group shown a differently computer-modified photograph of the same person. Extent and location of the lesion were varied systematically. Participants were asked to rate the person in the photograph with respect to intellectual ability, social competence and psychological adjustment. The scores from those questions were analysed with one way analysis of variance (ANOVA) then Tukey's HSD where ANOVA revealed significant differences. The data confirmed previous studies that have shown that poor dental condition is highly correlated with perceived poor social performance and intellectual ability. Further, the data showed that with respect to the constructs of intellectual ability, extraversion and care for one's personal appearance, a more central position of caries is more predictive of poor social judgements than just the presence of visible decay, or even twice the amount of decay. We discuss the possible evolutionary and ontological reasons for making social judgements that are influenced by a person's dental health as well as considering the implications of our findings for dentists.

IOrthoPredictor

In this paper, we present iOrthoPredictor, a novel system to visually predict teeth alignment in photographs. Our system takes a frontal face image of a patient with visible malpositioned teeth along with a corresponding 3D teeth model as input, and generates a facial image with aligned teeth, simulating a real orthodontic treatment effect. The key enabler of our method is an effective disentanglement of an explicit representation of the teeth geometry from the in-mouth appearance, where the accuracy of teeth geometry transformation is ensured by the 3D teeth model while the in-mouth appearance is modeled as a latent variable. The disentanglement enables us to achieve fine-scale geometry control over the alignment while retaining the original teeth appearance attributes and lighting conditions. The whole pipeline consists of three deep neural networks: a U-Net architecture to explicitly extract the 2D teeth silhouette maps representing the teeth geometry in the input photo, a novel multilayer perceptron (MLP) based network to predict the aligned 3D teeth model, and an encoder-decoder based generative model to synthesize the in-mouth appearance conditional on the original teeth appearance and the aligned teeth geometry. Extensive experimental results and a user study demonstrate that iOrthoPredictor is effective in qualitatively predicting teeth alignment, and applicable to the orthodontic industry.

Diagnosis of Occlusal Tooth Wear Using 3D Imaging of Optical Coherence Tomography Ex Vivo.

The aim of this study was to assess the utility of 3D imaging of optical coherence tomography (OCT) for the diagnosis of occlusal tooth wear ex vivo. Sixty-three extracted human molars with or without visible tooth wear were collected to take digital intraoral radiography and 3D OCT images. The degree of tooth wear was evaluated by 12 examiners and scored using 4-rank scale: 1—slight enamel wear; 2—distinct enamel wear; 3—tooth wear with slight dentin exposure; 4—tooth wear with distinct involvement of dentin. The degree of tooth wear was validated by the histological view of confocal laser scanning microscopy (CLSM). The sensitivity, specificity, and area under the curve (AUC) of receiver operating characteristic analysis were calculated. Diagnostic accuracy was compared with the agreement with CLSM observation using weighted kappa. The results were statistically analyzed at a significance level of α = 0.05. Three-dimensional OCT showed significantly higher sensitivity (p < 0.05) for all the diagnostic thresholds of enamel wear and dentin exposure than digital radiography (0.82, 0.85, and 0.79 vs. 0.56, 0.52, and 0.57, respectively). Three-dimensional OCT showed higher AUC and kappa coefficients than digital radiography (p < 0.05), where mean AUC and Kappa values were 0.95 and 0.76 for OCT and 0.92 and 0.47 for radiography, respectively. No significant difference of specificity was observed (p > 0.05). Three-dimensional OCT could visualize and estimate the degree of tooth wear and detect the dentin exposure at the tooth wear surface accurately and reproducibly. Consequently, a new guideline for tooth wear assessment can be proposed using OCT.