Risk factors for postoperative infection after bilateral sagittal split ramus osteotomy: A retrospective analysis.

BACKGROUND: This retrospective clinical study investigated risk factors for infection following bilateral sagittal split ramus osteotomy (BSSO) as orthognathic surgery, including the patients' general condition, local factors, and surgical factors. PATIENTS AND METHODS: The cases of 160 mandibular sites of 80 Japanese patients (26 males, 54 females; mean ± SD age: 25.3 ± 7.7 years, range 16-55 yrs) with a jaw deformity who underwent BSSO orthognathic surgery at our Department of Oral and Maxillofacial Surgery between Jan. 2017 and Dec. 2022 were analyzed. Potential risk factors were classified as clinical predictive variables. Descriptive and univariate statistics were computed. A multivariate analysis was performed with logistic regression. RESULTS: Fifteen mandibular sites (9.4 %) were complicated with postoperative infection. The multivariate analysis revealed significant differences in facial asymmetry (OR 24.0, p = 0.0002) and the amount of mandibular movement (OR 0.664, p = 0.011) between the sites with and without infection. CONCLUSIONS: Among clinical variables, facial asymmetry was the strongest risk factor for post-BSSO infection, followed by the amount of mandibular movement.

Prevalence of mandibular asymmetry in different skeletal sagittal patterns.

OBJECTIVES: To analyze the prevalence of mandibular asymmetry in skeletal sagittal malocclusions. MATERIALS AND METHODS: PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, LIVIVO and gray literature (OpenGrey, ProQuest, and Google Scholar) were electronically searched. Two independent investigators selected the eligible studies, and assessed risk of bias and certainty of evidence (GRADE). One reviewer independently extracted the data and the second reviewer checked this information. Any disagreement between the reviewers in each phase was resolved by discussion between them and/or involved a third reviewer for final decision. RESULTS: Electronic search identified 5,132 studies, and 5 observational studies were included. Risk of bias was low in two studies, moderate in one, and high in two. The studies showed high heterogeneity. Mandibular asymmetry ranged from 17.43% to 72.95% in overall samples. Horizontal chin deviation showed a prevalence of 17.66% to 55.6% asymmetry in Class I malocclusions, and 68.98% in vertical asymmetry index. In Class II patients, prevalence of mandibular asymmetry varied from 10% to 25.5% in horizontal chin deviation, and 71.7% in vertical asymmetry index. The Class III sample showed a prevalence of mandibular asymmetry ranging from 22.93% to 78% in horizontal chin deviation and 80.4% in vertical asymmetry index. Patients seeking orthodontic or orthognathic surgery treatment showed greater prevalence of mandibular asymmetry. CONCLUSIONS: Skeletal Class III malocclusion showed the greatest prevalence of mandibular asymmetry. Mandibular vertical asymmetry showed a marked prevalence in all malocclusions. However, conclusions should be interpreted with caution due to use of convenience samples and low-quality study outcomes.

[What are the factors associated with mandibular asymmetries? A case-control study]. / Quels sont les facteurs associés aux latéromandibulies ? Une étude cas-témoins.

The treatment of mandibular asymmetry often requires a late surgical orthodontic protocol that certainly allows an improvement but no complete correction. Ideal would be to control the etiological factors which are still controversial. The aim of the study is to identify per and postnatal factors associated with the development of mandibular asymmetry. This case-control study was performed with a cohort of 100 individuals divided in two subgroups. A subgroup of 50 subjects with mandibular asymmetry and another subgroup of 50 subjects without mandibular asymmetry. The subjects included in the study had to be from 6 to 16 years old, have a complete orthodontic file and no congenital syndrom or pathology. The following factors have been assessed: gender, mode and date of birth, dental trauma, visual disorders, ENT problems and parafunctions. An inter-group comparison had been performed by using statistical tests (Chisquare test, Fisher test and odds ratios calculation). The associated factors with mandibular asymmetry are male gender, oral ventilation, short-term vaginal nasalization, dental trauma and visual disorders. Asthma (symmetrical character of the anomaly ?), prematurity and caesarean section (by absence of trauma at delivery ?) would not be considered as associated factors. This case-control study is a first-line study that allows the identification of factors that may be associated with mandibular asymmetry. Ideally, a larger-scale prospective cohort study to increase the pertinence would clarify the risk factors for the development of mandibular asymmetry.

Complications of botulinum toxin and fillers: A narrative review.

BACKGROUND: Cosmetic surgery and esthetic procedures have become a billion dollar industry owing to the ever-growing demand of the population to stay young. The injectable treatments including fillers and botulinum toxin have become highly popular because of their quick, predictable and lasting results in the management of facial wrinkles and rejuvenation. Although these treatment modalities are relatively safe, they are associated with certain side effects. AIMS: In this review, we will focus on the complications of fillers and botulinum toxin. PATIENTS/METHODS: The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles. Only articles available in English were considered for this review. RESULTS: Brow ptosis and asymmetry are common adverse effects of botulinum toxin while the most common adverse effects associated with fillers are the local injection related effects manifesting as erythema, edema, pain, and ecchymosis. CONCLUSION: It is important that the treating physician is well verse with the various fillers and botulinum toxin complications and their management as some of the complications can be severely debilitating.

Brow height asymmetry before and after eyelid ptosis surgery.

BACKGROUND: In the setting of upper eyelid ptosis, asymmetric eyebrow position may be observed and may contribute to overall facial asymmetry. In this study, the authors aim to elucidate the prevalence and predictors of brow height asymmetry in the setting of ptosis and to determine the effect of eyelid surgery on brow height asymmetry to guide preoperative evaluation and informed consent. METHODS: In this cohort study, patients undergoing posterior approach ptosis surgery, unilateral or bilateral, with or without blepharoplasty, were included. Exclusion criteria included heterotropia, history of brow surgery, and history of previous ptosis surgery. Clinically significant eyelid asymmetry was defined as a difference greater than or equal to 1 mm between right and left margin reflex distance 1 (MRD1) values. Brow asymmetry was defined as difference in pupil-to-brow (PTB) distance of greater than or equal to 3.5 mm. RESULTS: The sample included 228 patients. Preoperative brow asymmetry was found in 17.1% of the sample. Notably, half of the patients with preoperative brow asymmetry were found to have postoperative brow asymmetry. Logistic regression indicated that preoperative brow asymmetry was a predictor of postoperative brow asymmetry (odds ratio = 17.03, p < 0.01). In subgroup analysis of those with preoperative brow asymmetry, postoperative eyelid asymmetry was a predictor of postoperative brow asymmetry (odds ratio = 5.58, p < 0.01). No variables in the current investigation were found to predict brow symmetry in those with preoperative brow asymmetry. CONCLUSION: Understanding the limitations of ptosis surgery in altering brow symmetry helps manage patient expectations, prepare informed consent, and guide surgical and postsurgical planning.

Rural and urban differences in orthognathic surgical patients in the north east of Scotland.

We have previously identified differences in the presentation and treatment of cancer between patients who live in rural compared with urban areas, but have not yet seen differences in those treated by orthognathic surgery. We hypothesised that patients from areas further away from the hospital face higher costs to attend and may not present with minor problems as often as those who live nearby. We therefore retrospectively reviewed all those (n=216) who had presented for orthognathic surgery over a six-year period (May 2011 to May 2017). The severity of malocclusion and facial asymmetry was established by combining measurements of intraoperative movements. Rurality was measured as the distance from home to the hospital at the time of operation. Those with smaller intraoperative movements (less than 7mm combined movement) lived significantly closer to the hospital as the crow flies (mean difference 15.13 miles, 95% CI 0.20 to 30.48, p=0.05) and could travel there more quickly (mean difference 65minutes 95% CI 9.8 to 121.7, p=0.02) than those with larger movements. Our results suggest that patients with small malocclusions and slight facial asymmetry who live further away from the hospital, may be less likely to present for operation than those who live closer. We explain why socioeconomic class is unlikely to confound our results, and suggest potential ways to minimise the effect observed.

Demographic features in Unilateral Condylar Hyperplasia: An overview of 309 asymmetric cases and presentation of an algorithm.

PURPOSE: Unilateral Condylar Hyperplasia (UCH) is an acquired deformity of the mandible, which can highly influence the symmetry of the face due to its progressive nature. It is caused by growth resembling pathology in one of the mandibular condyles. Definition as well as classification is subject to discussion. The aim of this study is to evaluate a large cohort of alleged UCH patients, and to describe the clinical characteristics, demographic features, classification and follow up. Secondly an algorithm is presented, in order to achieve uniformity in diagnosis and treatment. PATIENTS AND METHODS: From 1994 to 2014 a database of consecutive patients from 3 maxillofacial departments (Academic Medical Center, Amsterdam; VU Medical Center, Amsterdam and Spaarne Gasthuis, Haarlem) with suspected UCH was set up. Patients were referred by orthodontists, dentists, general practitioners or maxillofacial surgeons. Demographic features, bonescan outcomes, laterality, classification and follow-up were noted. Secondarily, all patients were retrospectively diagnosed by one surgeon (JWN), using available documentation. Missing data and follow-up were additionally retrieved from orthodontic offices. RESULTS: 394 asymmetric patients were evaluated. In 309 (78%) patients, the diagnosis UCH was justified and SPECT data were available. The mean age at presentation was 20.3 years (SD ± 7.7, range 9.0-54.5 years). In 48% of the patients, the bonescan was positive. 80% of these patients received surgical treatment, of which 62% were treated with a condylectomy only, 33% were treated with condylectomy plus additive corrective surgery, and 5% underwent corrective surgery only. Of the patient group without positive bonescan 42% of the patients received surgical treatment: 34% condylectomy only, 15% condylectomy plus additive corrective surgery, and 51% corrective surgery only. In total (N = 309) 96 (31%) patients underwent condylectomy as only surgical treatment and 124 (40%) patients received no surgical treatment at all. Treatment could be finalized with orthodontic treatment without further surgery in 64% and 41% respectively. 96 patients were subject to comparison of the classification as noted by the clinician and the author (JWN). In only 72% of the cases, the secondary screening was in agreement with the initial classification. CONCLUSION: Based on this study not all (active) UCH patients require corrective (orthognathic) surgery. A (transoral) partial condylectomy for active patients is recommended, with a postoperative remodeling period of 6 months with or without orthodontic treatment. Second stage correcting surgery may be necessary upon evaluation, using general orthognathic diagnostic and planning procedures. It appears difficult to classify patients reliably using the available clinical and radiological documentation. Objectivity and quantification in the diagnostic process is necessary: uniformity in documentation and parameters. The attached documentation form and UCH treatment algorithm is recommended.

Facial Paralysis in Patients With Hemifacial Microsomia: Frequency, Distribution, and Association With Other OMENS Abnormalities.

Although facial paralysis is a fundamental feature of hemifacial microsomia, the frequency and distribution of nerve abnormalities in patients with hemifacial microsomia remain unclear. In this study, the authors classified 1125 cases with microtia (including 339 patients with hemifacial microsomia and 786 with isolated microtia) according to Orbital Distortion Mandibular Hypoplasia Ear Anomaly Nerve Involvement Soft Tissue Dependency (OMENS) scheme. Then, the authors performed an independent analysis to describe the distribution feature of nerve abnormalities and reveal the possible relationships between facial paralysis and the other 4 fundamental features in the OMENS system. Results revealed that facial paralysis is present 23.9% of patients with hemifacial microsomia. The frontal-temporal branch is the most vulnerable branch in the total 1125 cases with microtia. The occurrence of facial paralysis is positively correlated with mandibular hypoplasia and soft tissue deficiency both in the total 1125 cases and the hemifacial microsomia patients. Orbital asymmetry is related to facial paralysis only in the total microtia cases, and ear deformity is related to facial paralysis only in hemifacial microsomia patients. No significant association was found between the severity of facial paralysis and any of the other 4 OMENS anomalies. These data suggest that the occurrence of facial paralysis may be associated with other OMENS abnormalities. The presence of serious mandibular hypoplasia or soft tissue deficiency should alert the clinician to a high possibility but not a high severity of facial paralysis.

Ten years of observations and demographics of hemimandibular hyperplasia and elongation.

INTRODUCTION: The full epidemiology and etiology of hemimandibular hyperplasia (HH) has not yet been clarified. In most cases it starts before puberty and results in various forms of dento-alveolar and skeletal discrepancies. This study is the first attempt at evaluating and describing some of the authors' key experiences, clinical philosophical approach, and gathered demographic data on hemimandibular hyperplasia and hemimandibular elongation (HE) among the Polish population. MATERIAL AND METHOD: A total of 45 patients (M = 8; F = 37; p < 0.05) with HE (n = 16; 35.6%; p < 0.05), HH (n = 28; 62.2%; p < 0.05), or HH + HE (n = 1; 2.2%; p > 0.05) had been diagnosed and treated. Epidemiological, geographical, and clinical data concerning the occurrence and treatment protocols in these mandibular malformations were measured in the Polish study groups. RESULTS: Women more often suffered from these mandibular malformations (82-87%). The occurrence of the first symptoms was highest at the age of 13-15 years and was statistically significant for both sides (p < 0.05). The disorders were found earlier in young girls, therefore an early compensatory orthodontic treatment in some cases had been used with a limited degree of success (p > 0.05). All values of bone scintigraphy were significant (p < 0.001). CONCLUSIONS: A very fast growth with visible major asymmetry and enlarged condylar head should be an indication for condylectomy. Women's expectations from surgery and treatment are more demanding than men's, a fact that is connected with the predominance of females in the study group. Almost all possible treatment alternatives are not only related with the degree of skeletal deformity, but also with the patient's willingness to undergo any necessary treatment protocols, which in most cases involve more than one stage. Skeletal scintigraphy tests are an important factor in estimating bone growth and possible surgical approaches in these disorders.

Three-dimensional assessment of facial asymmetry in preschool patients with orofacial clefts after neonatal cheiloplasty.

OBJECTIVES: To evaluate facial asymmetry changes in pre-school patients with orofacial clefts after neonatal cheiloplasty and to compare facial asymmetry with age-matched healthy controls. METHODS AND MATERIALS: The sample consisted of patients with unilateral cleft lip (UCL), unilateral cleft lip and palate (UCLP), and bilateral cleft lip and palate (BCLP). The patients were divided in two age groups with a mean age of 3 years (n = 51) and 4.5 years (n = 45), respectively, and 78 age-matched individuals as controls. Three-dimensional (3D) facial scans were analyzed using geometric morphometry and multivariate statistics. RESULTS: Geometric morphometry showed positive deviations from perfect symmetry on the right side of the forehead in the intervention groups and the controls. The UCL groups showed the greatest asymmetric nasolabial area on the cleft-side labia and the contralateral nasal tip. The UCLP group showed, moreover, asymmetry in buccal region due to typical maxillar hypoplasia, which was accentuated in the older group. The BCLP groups showed slightly similar but greater asymmetry than the control groups, except for the philtrum region. CONCLUSIONS: Asymmetry of each of the cleft groups significantly differed from the controls. Except for the buccal region in the UCLP and BCLP groups, asymmetry did not significantly increase with age.

The Individualized Facelift Technique in Improving Facial Asymmetry for Asian Patients.

PURPOSE: Among multiple influential factors affecting facial symmetry, the role of soft tissue is often overlooked. Skin and skeletal differences between Asian and Caucasian people also require the adaptation of current techniques for Asian patients. This article aimed to explore the ability of individual facelift techniques to improve facial symmetry and reset youthful eye in Asian people, while a new method, called the grid method, was tried to evaluate the improvement in facial symmetry. METHODS: The authors conducted a review of 58 consecutive facelifts, which were all performed by a single surgeon between April 2009 and December 2016 following institutional review board approval. Among them, 21 patients underwent lower eyelid blepharoplasty. The original frontal photograph of each patient was evaluated by the grid method. Five independent plastic surgeons reviewed the facial asymmetry of the images before and after the operations using a visual analog scale to analyze the facial asymmetry of the patients. RESULTS: In the preoperative group evaluated by the grid, the mean facial asymmetry score was 4.11, while in the postoperative group, the mean score was 1.07, which was significantly lower than the mean score before the operation (p < 0.001). The change in mean scores illustrated that the technique was effective in improving facial symmetry in Asian people. A total of 8 patients experienced hematomas and recovered well without obvious sequelae. CONCLUSIONS: The individual facelift technique was effective for improving facial symmetry and reshaping youthful eye in Asian people.

Effect of Facial Parameters in Primary Acquired Nasolacrimal Duct Obstruction.

PURPOSE: In this study, the authors aimed to identify facial and nasal parameters, which may create an anatomic disposition toward obstruction in patients with primary acquired nasolacrimal duct obstruction. MATERIALS AND METHODS: Forty-eight patients (14 males and 34 females) who presented to the ophthalmology outpatient clinic and were diagnosed with primary acquired nasolacrimal duct obstruction between January 2014 and January 2015 were included in the study. The control group comprised 59 patients (38 females and 21 males) without nasolacrimal duct obstruction. Measurements of nasal height, length, and depth, presence of a nasal hump, alar width and alar angle, distance between the maxillary bone nasal notches, and right and left distances between outer canthi and corners of the mouth were made using photographs of the patients. The presence of facial asymmetry was also assessed. RESULTS: Facial asymmetry (P = 0.014) and nasal hump (P = 0.048) were more common in the patient group. The patient group had smaller nasal radix depth (P < 0.001), nasal length (P = 0.001), and alar width (P < 0.001), larger distance between maxillary bone nasal notches (P < 0.001), and smaller alar angle (P < 0.001). CONCLUSION: In the current study, the authors found that primary acquired nasolacrimal duct obstruction occurred more frequently on the side of the face with shorter facial measurements. Smaller nasal radix depth, nasal length, and alar base width, presence of a nasal hump and longer distance between maxillary bone nasal notches may form an anatomic basis for nasolacrimal duct obstruction. Based on our results, the authors believe that primary acquired nasolacrimal duct obstruction is associated with facial structure.

Implications of Facial Asymmetry in Rhinoplasty.

Many rhinoplasty patients present with a chief complaint of nasal deviation and are unaware of any inherent facial asymmetries; however, recognizing and discussing the interrelation between the deviated nose and facial asymmetry is an important consideration in surgical planning. The objective of this study was to evaluate whether a surgeon's subjective assessment of facial analysis in the setting of nasal deviation correlates with objective anthropometric measurements. In addition, this study sought to further quantify the frequency of facial asymmetry associated with nasal deviation to highlight important anatomical trends for the rhinoplasty surgeon. Finally, this study presents the senior author's (R.J.R.) method of addressing a deviated nose on an asymmetric face. In this study, the authors demonstrated that nasal deviation is closely related to facial asymmetry. Furthermore, the authors demonstrated that objective facial analysis closely correlates to anthropometric facial measurements. In addition, the wide side of the face correlates to the short side of the face and the nose tends to deviate away from the wide side of the face. During surgical correction of the deviated nose in the setting of facial asymmetry, the surgeon's goal should be to obtain nasal symmetry and center the nose on a line between the mid glabella and the mid Cupid's bow. This may reduce the perception of a facial asymmetry, leading to increased patient satisfaction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.

Prevalence and Associated Factors of Mandibular Asymmetry in an Adult Population.

BACKGROUND: This study aimed to estimate the prevalence of mandibular asymmetry and investigate some associated factors. METHODS: Tomographic images of 952 individuals aged from 18 to 75 years old were analyzed. The investigated outcome was mandibular asymmetry. The explanatory variables included gender, age, absence of posterior teeth, and sagittal jaw relationship of the individuals. Statistical analyses included the chi-squared and the Poisson regression with robust variance. RESULTS: Mandibular asymmetry was present in 17.4% of the sample (95% confidence interval 15.2-20.0). In the bivariate analysis, there was an association between the variables age and sagittal jaw relationship with mandibular asymmetry (P = 0.026 and P = 0.018, respectively). However, in the adjusted regression model, the association with age was not maintained, occurring only an association between sagittal jaw relationship and mandibular asymmetry (P = 0.045), with significant difference between individuals with skeletal Class II and skeletal Class III (P = 0.013). CONCLUSION: Mandibular asymmetry was not independently associated with sex, age, or absence of posterior teeth. The only verified independent association was between mandibular asymmetry and sagittal jaw relationship.

Lower face asymmetry as a marker for developmental instability.

OBJECTIVES: Fluctuating asymmetries in the craniofacial skeleton have been shown to be predictive for mortality from degenerative diseases. We investigate whether lower face asymmetries are a potential marker for the developmental origins of health and disease. METHODS: The lower face of a representative sample of 6654 12- to 17-year old United States (US) adolescents (1966-1970, National Health Examination Survey III) was classified as asymmetric when the mandibular teeth occluded prognathically (forward) or retrognathically (backward) on one side of the face only. It was investigated whether these lower face asymmetries were directional (preferentially to the left or the right) or fluctuating (random left-right distribution) in the US population. RESULTS: Lower face asymmetries affected 1 in 4 of the US adolescents. Unilateral retrognathic dental occlusions were fluctuating asymmetries, had a US prevalence of 17.0% (95% confidence interval: 15.5-18.4) and were associated with race/ethnicity (P < .0001), not with handedness (P < .7607). Unilateral prognathic dental occlusions were directional asymmetries (P < .0001), had a US prevalence of 7.6% (95% confidence interval: 6.4-8.7) and were associated with large household size (P < .001) and handedness (P < .0223). Lower face asymmetries were not associated with distinct heritable traits such as color blindness. CONCLUSIONS: The findings suggest that lower face asymmetries are a marker for environmental stress and cerebral lateralization during early development.

Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations.

The expression of facial asymmetries has been recurrently related with poverty and/or disadvantaged socioeconomic status. Departing from the developmental instability theory, previous approaches attempted to test the statistical relationship between the stress experienced by individuals grown in poor conditions and an increase in facial and corporal asymmetry. Here we aim to further evaluate such hypothesis on a large sample of admixed Latin Americans individuals by exploring if low socioeconomic status individuals tend to exhibit greater facial fluctuating asymmetry values. To do so, we implement Procrustes analysis of variance and Hierarchical Linear Modelling (HLM) to estimate potential associations between facial fluctuating asymmetry values and socioeconomic status. We report significant relationships between facial fluctuating asymmetry values and age, sex, and genetic ancestry, while socioeconomic status failed to exhibit any strong statistical relationship with facial asymmetry. These results are persistent after the effect of heterozygosity (a proxy for genetic ancestry) is controlled in the model. Our results indicate that, at least on the studied sample, there is no relationship between socioeconomic stress (as intended as low socioeconomic status) and facial asymmetries.

Prevalencia de asimetrías mandibulares en radiografías panorámicas de población de Bogotá-Colombia / Mandibular asymmetries prevalence in panoramic radiographies in a Bogotá­ Colombia population

La simetría mandibular es esencial para determinar los patrones no solo de belleza facial sino de función masticatoria; las alteraciones de crecimiento y desarrollo, patologías genéticas, traumáticas o neoplásicas o por características propias de cada población, que afectan a la mandíbula, generan consecuencias que llevan a tratamientos inclusive quirúrgicos para su corrección. El análisis de Thilander en radiografías panorámicas, permite la valoración de la magnitud de las asimetrías mandibulares, como parte de los exámenes complementarios en el proceso diagnóstico. Determinar la frecuencia de asimetrías condilares, de cuerpo y rama mandibular en radiografías panorámicas digitales. Estudio descriptivo de corte transversal en 500 radiografías panorámicas digitales, de adecuado contraste y densidad, obtenidas de pacientes mayores de 18 años de edad, con dentición completa; se registró sexo, edad y mediante el programa CliniView 9.1 se tomaron las medidas mandibulares propuestas por Thilander calculando las diferencias con la fórmula de Bezzur. La prevalencia de asimetrías condilares patológicas en la población mayor de 18 años es del 6 %. Se encontró una diferencia significativa en las medidas verticales entre los dos lados sin que en ellas tenga influencia el género o la edad. Las diferencias en la altura de la rama mandibular se encuentran en la mayoría de los casos a expensas del cóndilo y las discrepancias entre los lados derecho e izquierdo, deben considerarse como elemento diagnóstico en posibles patologías articulares.

The mandibular symmetry is essential to determine the patterns, not only of facial beauty, but also in the masticatory function. The growth and development alterations, genetic pathologies, traumatic, neoplasic or the characteristics of each population, that affect the jaw, generate consequences that may lead to even surgical treatments for correction. Thilander analysis on panoramic x-rays, allows the assessment of the magnitude of mandibular asymmetries, as part of the complementary exams in the diagnostic process. The objective of the study was to determine the frequency of condylar asymmetries in mandibular body and ramus in digital panoramics x-rays. A cross-sectional study was carried out in 500 digital panoramic x-rays with adequate contrast and density, obtained from patients over 18 years of age, with full dentition. Sex and age were registered by 9.1 CliniView program. Proposed mandibular measurements were recorded by Thilander, calculating the differences with the Bazzur's formula. The prevalence of pathological condylar asymmetries in the population over 18 years is 6 %. A significant difference was found in the vertical measurements between the two sides, though there was no influence by either sex or age. The differences in the height of the mandibular ramus are, in most cases, at the expense of the condyle. The discrepancies between the left and right sides must be considered as diagnostic element in possible articular pathologies.

Is there an association between skeletal asymmetry and tooth absence?

INTRODUCTION: Facial skeletal asymmetry is commonly found in humans and its main characteristic is menton deviation. The literature suggests that occlusal and masticatory problems arising from tooth absence could be related to the development of such asymmetries. OBJECTIVE: The aim of this cross-sectional study was to estimate the prevalence of mandibular skeletal asymmetries and to investigate its association with posterior tooth absences. METHODS: Tomographic images of 952 individuals aged from 18 to 75 years old were used. Asymmetry was the analyzed outcome, and it was categorized into three groups according to gnathion displacement in relation to the midsagittal plane (relative symmetry, moderate asymmetry, and severe asymmetry). Patients were sorted by the presence of all posterior teeth, unilateral posterior tooth absence, or bilateral posterior tooth absence. Chi-square test with a significance level of 5% was used to verify the association between posterior tooth absence and asymmetry. RESULTS: Results show relative symmetry present in 55.3% of the sample, as well as the prevalence of 27.3% for moderate mandibular asymmetry and 17.4% for severe asymmetry. Moderate and severe mandibular asymmetries occurred in a higher proportion in patients with unilateral posterior tooth absence. However, there was no statistically significant difference between the analyzed groups (p = 0.691). CONCLUSIONS: In this study, mandibular asymmetries did not present any association with the absence of teeth on the posterior area of the arch.

Análisis de crecimiento maxilar tras cirugía en paladar hendido no sindrómico / Maxillary growth analysis after surgery in non-syndromic cleft palate

Antecedentes y Objetivos. La finalidad del cierre de la hendidura palatina es el restablecimiento de la continuidad anatómica entre la cavidad oral y la nasal para conseguir una correcta fonación y un crecimiento maxilofacial normal. El propósito de este estudio es determinar si existe un crecimiento maxilar deficiente, en sentido ántero-posterior y transversal, entre los niños nacidos en el año 2003 con hendidura palatina aislada no sindrómica atendidos en el Hospital Nacional de Niños Dr. Carlos Sáenz Herrera de San José, Costa Rica. Material y Método. Desarrollamos una investigación de tipo transversal, descriptiva e intervencional, basada en datos de registros médicos y registros actuales (radiografía cefalométrica y modelo de estudio del maxilar). El grupo de estudio constó de 5 pacientes. Las técnicas estadísticas utilizadas fueron las distribuciones de frecuencia, cruce de variables y comparación de medias con base en el análisis de variancia. El nivel mínimo de confianza para las comparaciones fue del 95%. Resultados. El promedio de edad de ejecución de la cirugía primaria del paladar fue de 17 meses. La asimetría transversal del arco maxilar predominó en este estudio. Encontramos también una correlación positiva, alta y estadísticamente significativa, entre la diferencia de la posición ántero-posterior del maxilar con respecto a la mandíbula. Conclusiones. Comprobamos una asimetría transversal del arco maxilar que podría ser influenciada por el proceso de cicatrización secundaria del paladar ante un hueso denudado quirúrgicamente. La relación ántero-posterior no estuvo afectada. Recomendamos realizar un estudio a diferentes edades del niño, ya que la relación ántero-posterior puede manifestarse tardíamente como una condición determinada genéticamente (AU)

Background and Objectives. The goal of closing the cleft palate is the restoration of the anatomic continuity between the oral and nasal cavities, in order to obtain a correct speech and a normal maxillofacial growth. The purpose of this study is to determine if there is a poor anteroposterior and transverse maxillary growth in children born in 2003 with non-syndromic isolated cleft palate, treated at the Hospital Nacional de Niños Dr. Carlos Sáenz Herrera, San José, Costa Rica. Methods. The study was a cross-sectional, descriptive, interventional study, based on data from medical records and current records (cephalometric radiograph and maxillary study cast). The study group consisted of 5 patients. The statistical techniques used were frequency distributions, cross variables and mean comparison based on the analysis of variance. The minimum level of confidence for comparisons was 95%. Results. The average age of the primary palate surgery was 17 months old. The maxillary arch transverse asymmetry predominated in this study. There is a positive, high and statistically significant correlation between the difference in the anterior-posterior position of the maxilla with respect to the mandible. Conclusions. There is a maxillary arch cross asymmetry which could be influenced by secondary healing process palate to a surgically denuded bone. The anterior-posterior relationship is not affected. A study at different ages of children is recommended since the antero-posterior relationship can be expressed as a belatedly condition genetically determined (AU)

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