"Over-reviewing" of research? An analysis of orthodontic reviews.

INTRODUCTION: Research overviews may be undertaken to identify gaps in the literature, evaluate existing systematic reviews (SRs), and summarize evidence. This paper aims to profile overviews that have been conducted in orthodontics and related interventions since 2012 and to evaluate the degree of overlap among these overviews. METHODS: Overviews published between January 1, 2012 and June 20, 2023 were identified using an electronic search involving Google Scholar and PubMed. A descriptive summary was produced, and citation matrices were used to evaluate the percentage of overlap between overviews using corrected covered area and covered area. This was classified as slight, moderate, high, or very high. RESULTS: A total of 35 overviews were identified across a wide range of topics. Eight overviews included <10 SRs; 21 had 10-20 SRs; and 6 included >20 SRs (median no. of SRs per overview, 15; range, 3-62). Meta-analysis was conducted in only 5 overviews. Overlap between overviews on the same topic ranged from slight (2.7%) to very high (53.8%). CONCLUSIONS: Almost all overview topics address treatments and their effects, with a wide variation in the number and quality of SRs included. There is considerable overlap in some orthodontic overviews, suggesting unnecessary duplication and research waste. Researchers should be encouraged to focus on primary data collection to add more high-quality data to SRs, which will ultimately enhance the yield from secondary and tertiary orthodontic research.

Self-harm, dentofacial features, and bullying.

INTRODUCTION: Self-harm is a growing public health problem. The study aimed to investigate the prevalence of self-harm among a representative sample of school children and the contribution of dentofacial appearance and being bullied because of dentofacial appearance to self-harm. METHODS: This was a cross-sectional study in which a representative sample of eighth-grade students (aged 13-14 years) from randomly selected schools was asked to complete anonymous questionnaires distributed in the classroom. The final sample size was 699 children (339 girls, 360 boys) with a mean age of 13.3 years, representing 1.26% of the target population. RESULTS: The prevalence of self-harm was 26.9% (n = 188), with no statistically significant gender differences (P >0.05). Among all the subjects who reported self-harm, 47.9% (n = 90) reported self-harm because of dentofacial features. A total of 41 subjects reported self-harm because of bullying targeted at dentofacial features, representing around one fifth of subjects who reported self-harm. The 3 most common dentofacial features contributing to self-harm and self-harm as a result of bullying were tooth color and shape, spacing between the teeth or missing teeth, and prominent maxillary anterior teeth. CONCLUSIONS: This study demonstrated a relatively high experience of self-harm reported by adolescent school children, with many reporting self-harm as a result of their dentofacial appearance and bullying because of dentofacial features. The present study provides baseline data to better understand the relationship between self-harm and dentofacial features.

Quantitative investigation of the esthetic impact of lip prominence in relation to the esthetic line.

INTRODUCTION: The purpose of this quantitative investigation was to assess the influence of lip prominence in relation to the esthetic line (E-line) on perceived attractiveness and threshold values of desire for treatment. METHODS: The lip prominence of an idealized silhouette male white profile image was altered incrementally between -16 mm to 4 mm from the E-line. The images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). RESULTS: In terms of perceived attractiveness, lips to E-line distance within the ranges of -12 mm to -16 mm and 0-4 mm in relation to the E-line was associated with a reduction in median attractiveness scores to below 4 in the patient and clinician groups of observers; for the lay group, the corresponding ranges were -14 mm to -16 mm and 2-4 mm. Relative lip prominence appears to be viewed as more attractive than lip retrusion. Clinicians were generally least likely to suggest treatment for varying levels of bilabial position. For a number of the images, there was reasonable agreement among clinicians and laypeople regarding whether treatment is required. For the clinician group, the only categories for desire for treatment were at a lip to E-line distance within the ranges of -14 mm to -16 mm and 2-4 mm. CONCLUSIONS: It is recommended that the range of normal variability of the prominence of the lips and threshold values of the desire for treatment be considered in planning.

Three-dimensional virtual surgical planning (3D-VSP) in orthognathic surgery: Advantages, disadvantages and pitfalls.

In this article, the advantages, disadvantages and pitfalls of three-dimensional virtual surgical planning (3D-VSP) compared to traditional two-dimensional (2D) planning methods in orthognathic surgery are discussed, alongside a standardised protocol that can be utilised. A skeletal Class II, skeletal Class III and an anterior open bite clinical case along with their 3D-VSP management are presented, highlighting modifications that can be made to computer-aided design/computer-aided manufacture (CAD/CAM) cutting guide and plate designs.

The Opinion of Different Observer Groups About the Esthetic Impact and Need for Surgical Correction of Varying Submental Lengths.

PURPOSE: This study evaluated the opinion of different observer groups about the influence of the submental length on perceived attractiveness and when surgical correction was deemed necessary. MATERIALS AND METHODS: The submental length of an idealized silhouette of a white male profile was altered incrementally between 5 and 95 mm. Images were rated for attractiveness on a Likert scale by pretreatment orthognathic surgery patients (n = 75), laypersons (n = 75), and clinicians (maxillofacial surgeons and orthodontists) (n = 35). RESULTS: For perceived attractiveness, the ideal submental length was approximately 50 mm (range, 40 to 75 mm). A submental length shorter than or equal to 30 mm was deemed unattractive by all 3 groups. Overall, a submental length less than 40 mm generally was judged less attractive than a comparable increase in length. Clinicians were generally least likely to suggest surgery for varying submental lengths. For this group, the cutoff at which the majority suggested surgery was a submental length of 25 mm or less. For the patient and layperson groups, the corresponding cutoff values were a length shorter than or equal to 30 mm or equal to 95 mm. CONCLUSIONS: A submental length of approximately 50 mm (range, 40 to 75 mm) was viewed by most observers as attractive. At 30 mm or less, it was generally deemed progressively less attractive. Clinicians were less likely to suggest corrective surgery than were the patient and layperson groups. For comparative proportional relationships, the submental length should be between the lower lip-chin height and lower facial height, assuming an otherwise proportional facial profile.

Challenges and opportunities facing contemporary orthognathic surgery.

Here, we provide a brief overview of the challenges, innovations and potential opportunities facing contemporary management of individuals requiring orthognathic care.

Facial feminisation: an overview of the role of the surgeon and orthodontist.

Facial feminisation surgery (FFS) aims to feminise the face by changing masculine facial features to feminine ones. It is commonly undertaken for transsexual individuals who are transitioning from male to female or for women who wish to further feminise their facial appearance. Assessment and treatment planning by a multidisciplinary team is essential for any patient considering FFS. Orthodontists have an important role within this team as patients may first present to an orthodontist expressing concerns about the appearance of their jaws. Therefore, it is important that orthodontists have a detailed understanding of FFS procedures, to enable good patient communication, thorough patient assessment and onwards referral where required. This article reviews the common FFS procedures, their indications, and the benefits and risks of each procedure and highlights the role of the orthodontist.

Nasofrontal Angle and Nasal Dorsal Aesthetics: A Quantitative Investigation of Idealized and Normative Values.

This study is a quantitative evaluation of the influence of the lower component of the nasofrontal angle on perceived attractiveness and threshold values of desire for rhinoplasty. The nasofrontal angle of an idealized silhouette male Caucasian profile image was altered incrementally between 106 and 148 degrees. Images were rated on a Likert scale by pretreatment patients (n = 75), laypeople (n = 75), and clinicians (n = 35). The results demonstrated that a nasofrontal angle of approximately 130 degrees is ideal, corresponding to a lower component of 60 degrees, with a range of 127 to 142 degrees deemed acceptable. Angles above or below this range are perceived as unattractive, and anything outside the range of 118 to 145 degrees is deemed very unattractive. Reduced nasofrontal angles, simulating a nasal hump deformity, of less than 115 degrees were deemed the least attractive. In terms of threshold values of desire for surgery, for all groups a threshold value of 148 degrees indicated a preference for surgery: for patients, the threshold value was 121 degrees or less; for lay people, the threshold value was 124 degrees or less; and similarly for clinicians, the threshold value was 118 degrees or less. Clinicians were the least critical, and patients appeared to be less critical than lay people. This stresses the importance of using patients as observers, as well as laypeople and clinicians, in facial attractiveness research. From the results of this study, it is recommended that in rhinoplasty planning, the range of normal variability of the nasofrontal angle, in terms of observer acceptance, is taken into account as well as the threshold values of desire for surgery.

Relationship between maxillary central incisor proportions and facial proportions.

STATEMENT OF PROBLEM: No universally accepted parameter exists for selecting maxillary central incisors (MCIs) relative to facial proportions. PURPOSE: The purpose of this prospective clinical study was to determine the relationship between MCIs and facial height and width in adults, intersex differences, and measurement differences between right and left MCI. MATERIAL AND METHODS: A prospective study was undertaken of 149 dental students (F:76; M:73) aged between 18 and 30 years. Anthropometric MCI and horizontal and vertical facial measurements were recorded with digital calipers by 1 operator. Correlation was investigated with Pearson correlation coefficients (α=.05). Two-sample t tests were used for intersex comparisons and paired t tests to compare right and left MCIs. Intraexaminer reliability was tested by remeasuring 25 participants and applying the Bland-Altman and Lin analyses. RESULTS: The mean MCI height was 10.28 mm (right and left) and the mean widths were 8.65 mm (right) and 8.66 mm (left). Intersex incisor differences existed for height measurements (M:F 0.54 mm [right], 0.46 mm [left]) and width measurements (M:F 0.26 mm) but not for width-to-height ratios (F=0.85; M=0.84). A mean ratio of 15.56 was found between bizygomatic width:tooth width (M=15.75, F=15.37) and of 17.93 between total face height:MCI height (M=17.97, F=17.89). Correlation coefficients were low for all tooth:face measurements. Intraexaminer reliability was clinically acceptable. CONCLUSIONS: Men had larger teeth and faces but similar width:height ratios. There was no significant size difference between right and left MCI, little individual relationship between tooth:face proportions, and insignificant sex influence. The "biometric ratio"' of 1:16 for MCI:bizygomatic width was not reconfirmed exactly. A ratio of 1:18 is proposed for MCI height to total face height (Tr-Me') and 1:12 for face height (N'-Me').

Prospective assessment of maxillary advancement effects: maxillary incisor exposure, and upper lip and nasal changes.

INTRODUCTION: Our aim was to assess changes in maxillary incisor exposure, and upper lip and nasal soft tissues with maxillary advancement with or without impaction, accounting for the use of cinch sutures and VY closures. METHODS: This was a prospective study of 41 consecutive patients undergoing maxillary advancement with or without impaction. Lateral cephalometric radiographs and clinical measurements were taken preoperatively and up to 6 months postoperatively by 1 examiner. RESULTS: Thirty-one patients (19 female, 12 male) with a mean age of 25.5 years (range, 16.9-49.9 years) completed the study. Twenty-six received bimaxillary surgery. Fifteen had simple closures, 6 had cinch sutures, and 10 had alar base cinch and VY closures. The mean amounts of maxillary advancement and impaction were 3.34 and 1.6 mm, respectively. Soft tissues followed increasingly more closely the hard tissue advancement from pronasale to stomion superius. Mean maxillary incisor exposure increased at rest (0.5 mm) and on smiling (1.0 mm). The nasolabial angle increased (1.88°) because of columella upturning. Alar base width (3.09 mm) significantly increased. CONCLUSIONS: Soft to hard tissue horizontal ratios increased progressively from pronasale to stomion superius. Alar base cinch and VY closures increased these further. Maxillary incisor display changes were partly explained by presurgical upper lip thickness and soft tissue manipulation. Nasolabial angle increased, and cinch sutures seemed to increase this further. Alar base width increased significantly, and the cinch sutures did not significantly limit this.

The aesthetic impact of upper lip inclination in orthodontics and orthognathic surgery.

BACKGROUND: The nasolabial angle, particularly its lower component, i.e. the upper lip inclination (ULI), is an important keystone in treatment planning. Normative data for this parameter are not available. OBJECTIVES: A quantitative evaluation of the aesthetic impact of ULI on perceived attractiveness and threshold values of desire for treatment was undertaken. METHODS: The ULI of an idealized silhouette profile image was altered incrementally between 61 and 100 degrees. Images were rated on a Likert scale by pre-treatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). RESULTS: An ULI between 79 and 85 degrees is viewed as ideal, with a range of 73-88 degrees deemed acceptable. Angles above or below this range, down to 67 degrees and up to 94 degrees are perceived as slightly unattractive, and anything outside the range of 67-94 degrees is deemed very unattractive. For patients the threshold value of desire for treatment was 91 degrees and above and 64 degrees and below, and for both clinicians and lay people the threshold value was 94 degrees and above and 64 degrees and below. Patients appear to be more critical than lay and clinician groups. This stresses the importance of using patients as observers, as well as laypeople and clinicians, in facial attractiveness research. LIMITATIONS: The results are based on an idealized male Caucasian profile. CONCLUSIONS: It is recommended that in treatment planning, the range of normal variability of the ULI, in terms of observer acceptance, is taken into account as well as the threshold values of the desire for treatment.

Variability of the inclination of anatomic horizontal reference planes of the craniofacial complex in relation to the true horizontal line in orthognathic patients.

INTRODUCTION: The purpose of this study was to assess the reliability of the Frankfort horizontal (FH), sella-nasion horizontal, and optic planes in terms of their variabilities in relation to a true horizontal line in orthognathic surgery patients. METHODS: Thirty-six consecutive presurgical orthognathic patients (13 male, 23 female; age range, 16-35 years; 30 white, 6 African Caribbean) had lateral cephalometric radiographs taken in natural head position, with a plumb line orientating the true vertical line, and the true horizontal line perpendicular to the true vertical. The inclinations of the anatomic reference planes were compared with the true horizontal. RESULTS: The FH plane was found to be on average closest to the true horizontal, with a mean of -1.6° (SD, 3.4°), whereas the sella-nasion horizontal and the optic plane had means of 2.1° (SD, 5.1°) and 3.2° (SD, 4.7°), respectively. The FH showed the least variability of the 3 anatomic planes. The ranges of variability were high for all anatomic planes: -8° to 8° for the FH, -8° to 15° for the sella-nasion horizontal, and -6° to 13° for the optic plane. No significant differences were found in relation to patients' sex, skeletal patterns, or ethnic backgrounds. CONCLUSIONS: The clinically significant variability in the inclinations of anatomic reference planes in relation to the true horizontal plane makes their use unreliable in orthognathic patients.

The golden ratio-dispelling the myth.

BACKGROUND: The purpose of this article is to explore the claims often cited in scientific journals regarding the golden ratio, and its proposed link to beauty and idealized forms in nature, including idealized human proportions. MAIN BODY: Claims made in the nineteenth century through to the modern day in the clinical literature do not appear to be supported by evidence. SHORT CONCLUSIONS: There is no convincing evidence that the golden ratio is linked to idealized human proportions or facial beauty. There is currently no evidence to support the use of the golden ratio in orthognathic or facial aesthetic/reconstructive surgical planning or analysis of results.

The influence of combined orthodontic-orthognathic surgical treatment on perceptions of attractiveness: a longitudinal study.

The purpose of this investigation was to quantitatively evaluate the influence of completing the orthognathic treatment process on patients' perceptions of attractiveness and their desire for surgical correction. The mandibular prominence of an idealized profile image was altered in 2 mm increments from -16 to 12 mm, in order to represent retrusion and protrusion of the mandible, respectively. These images were rated on a seven-point Likert scale by 50 patients at T1 (pre-treatment) and T2 (6 months following orthodontic appliance removal). At T1, mandibular retrusion became noticeable at -4 mm and protrusion at 2 mm. The results remained unchanged at T2. Surgery was desired from -9 mm at T1 and -10 mm at T2. For mandibular protrusion, surgery was desired from 3 mm at T1 and 4 mm at T2. The odds of desire for surgery were reduced by 85 per cent for those patients who had undergone bimaxillary surgery in relation to those with single jaw surgery. The lowest rated images demonstrated severe degrees of mandibular protrusion and retrusion. The highest rated images represented the idealized facial profile and minor variations thereof; there was little change in perception between T1 and T2. Going through the process of orthognathic treatment does not appear to have any significant effect on patients' perceptions of facial profile attractiveness or the limits of mandibular sagittal deviation at which they would desire surgery. The clinician's information provision during treatment does not seem to unduly influence orthognathic patients and does not make them more critical of jaw deformities.

How does variation in lower anterior face height influence perceived attractiveness? A quantitative investigation.

OBJECTIVE: The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of lower anterior face height (LAFH) variations influences perceived attractiveness. DESIGN: Cross-sectional study SETTING: St George's Hospital, London, UK PARTICIPANTS AND METHODS: The LAFH of an idealized male and female frontal facial image were altered in 2·5 mm increments from -20 to 20 mm (male images) and from -10 to 20 mm (female images), in order to represent reduction and increase in height of this region. These images were rated by a pre-selected group of pre-treatment orthognathic patients (n = 75), clinicians (n = 35) and laypersons (n = 75). OUTCOME MEASURES: Ratings on a seven-point Likert scale. RESULTS: With an increase in LAFH, desire for surgery became significant at 15-16 mm for male faces and 13-14 mm for female faces. With a reduction in LAFH, desire for surgery became significant at -14 to -17 mm for male faces; a smaller reduction of -6 to -8 mm led to a significant desire for surgery for female faces. CONCLUSIONS: The classical vertical facial trisection canon of upper face height as one-third (33·3%), midface height as one-third (33·3%) and LAFH as one-third (33·3%) of total anterior face height may be used as an 'ideal' proportional ratio. Mild LAFH variations were largely acceptable. In terms of the percentage LAFH to total anterior face height (TAFH) and anterior face height (AFH), observers did not desire surgery for LAFH variations of 25-42% of TAFH (40-66% of AFH) for male faces, and 28-42% of TAFH (45-66% of AFH) for female faces.

Zonal analysis in contemporary aesthetic orthognathic surgical planning.

BACKGROUND: The purpose of this article is to introduce the concept of zonal analysis in orthognathic surgical planning. CASE PRESENTATION: The importance of developing this concept of facial zonal analysis is because grouping together elements of aesthetic importance in a region in a systematic manner allows for accurate diagnosis and logical treatment planning. An orthognathic case presentation is described to demonstrate this concept. DISCUSSION: The three facial zones described are related in terms of the presenting problem and in relation to the changes envisaged with each planned surgical movement. The importance of developing this concept of facial zonal analysis is because grouping together elements of aesthetic importance in a region in a systematic manner allows for accurate diagnosis and logical treatment planning. Consideration is given to the negative features that require improvement and the positive features that the clinician and patient would prefer not to alter. It also provides an organised tool for postoperative comparison of results. The analysis and synthesis of the information provided from this approach can aid contemporary orthognathic surgical planning.