Academic literature on the topic 'Retrognathic Mandible'

Introduction Mandibular retrognathism is considered to be the most important risk factor for upper airway obstruction. Aim This cross-sectional study intended to examine the relationship between craniofacial morphology and the pharyngeal airway space (PAS) in patients with mandibular retrognathism and mandibular prognathism, when compared to normal subjects. The study also analyzed the influence of mandibular morphology on pharyngeal length (PL). Materials and Methods The PAS was assessed in 92 females (age 15-30 years) further divided into three groups - Group 1- normal mandible (76°≤ SNB ≤82°; n = 31); Group 2-mandibular retrognathism (SNB <76°; n = 31); Group 3-Mandibular prognathism (SNB >82°; n = 30). All subjects were examined by lateral cephalometry with head position standardized using an inclinometer. Craniocervical angulation, uvula length, thickness and angulation were compared among different groups. Results The results showed no statistically significant difference in the pharyngeal airway between the three groups. Measurements of PL showed statistically significant higher values for retrognathic mandible group than normal and prognathic mandible group. Conclusion There is no significant difference between PAS between patients with mandibular retrognathism, normal mandible and mandibular prognathism. Mandibular retrognathism patients show a significantly higher uvula angulation than patients with mandibular prognathism. Craniocervical angulation showed maximum value in retrognathic mandible group followed by normal and prognathic mandible group respectively. Mean PL for retrognathic mandible patients was significantly higher than prognathic mandible patients.

Aim: The aim of this study was to evaluate specific single nucleotide polymorphisms (SNP) of transforming growth factor-beta (TGF-β) (rs1800469) and insulin-like growth factor-1 (IGF-1) (rs17032362) genes in Class II individuals with a normal maxilla and retrognathic (short) mandible. Materials and methods: The study had 25 participants: 5 were assigned to the control group, which had a normal maxilla and mandible, and 20 to the experimental group, which had a structurally retrognathic mandible and a normal maxilla. The polymerase chain reaction was used with preselected primers after which Sanger sequencing was used to identify individual mutations. Results: SNP at rs1800469 (TGF-β) in the study and control groups showed significant difference (p=0.009). The Odds Ratio of 5.28 signified that the individuals with SNP at rs1800469 were at 5.28 times higher risk of developing mandibular retrognathism. The IGF SNP showed its presence in experimental group but was not statistically significant. Conclusion: Our study reports for the first time on the association between TGF-βSNP and mandibular retrognathism. Other SNP also showed its presence in the study group and its complete absence from control group directs us for further research.

ABSTRACT Objectives To compare 2D:4D ratio which is determined by testosterone levels with patients having orthognathic, retrognathic and prognathic mandibles. Materials and methods The study was performed at Chennai, on 320 subjects of which, 60 subjects (32 males and 28 females) had retrognathic mandible; 55 subjects (25 males and 30 females) had prognathic mandible and 205 subjects (98 males and 107 females) had normal mandible. All the subjects had a normal maxilla and were in the age group of 18 to 25 years. 2D:4D ratio was determined using the photocopies of the ventral surface of right hand made with vernier calipers of 0.01 mm accuracy. Statistical analysis was undertaken using Student's t- test, ANOVA test and TukeyHSD test. Results (i) Low 2D:4D is seen in subjects with mandibular prognathism, (ii) Among females, low 2D:4D is seen only in prognathic mandible. Conclusion These findings highlight the fact that testosterone plays an important role in mandibular growth. Thus 2D:4D, a least invasive and reproducible procedure can be used as an early marker for mandibular progathism, and as a diagnostic tool in correlating the mandibular growth with causal relations between hormones and craniofacial development. How to cite this article Premkumar S, Gurumurthy B. Assessment of 2D:4D in Subjects with Anteroposterior Mandibular Dysplasia. J Contemp Dent Pract 2013;14(4):582-585.

This case report describes the successful second surgical treatment of a 26-year-old white female patient with a retrognathic mandible and previous bilateral total joint prostheses placement. The patient had previously presented with bilateral idiopathic condylar resorption (ICR) which caused clockwise mandibular rotation and resulted in anterior open bite and a retrognathic mandible. The patient had undergone definitive corrective for the ICR where condylectomies were performed bilaterally. In addition, total joint prostheses using ‘stock joints’ were used to restore the condyle and glenoid fossa on both sides. Although the previous surgery corrected the anterior open bite and restored the condyles, the patient was still suffering from joint symptoms (significant pain), restricted mandibular movements, increased overjet (12 mm) and a retrognathic mandible. The treatment plan included a combined orthodontic surgical approach: (1) bimaxillary orthognathic surgery: a surgical procedure on the mandible to reposition the prosthetic joints and correct the mandible position, and a segmental LeFort I to expand the maxilla; and (2) post-surgical orthodontics treatment to detail the occlusion. At the end of the treatment, good aesthetic and functional results were obtained with the cooperation of two specialties. This case emphasises the importance of three-dimensional planning and multidisciplinary treatment when addressing complex jaw movements. It also emphasises the importance orthodontic planning and collaboration with the orthodontist.

Functional appliances, fixed or removable, are primarily orthopaedic tools used to influence the facial skeleton in a growing child. Class II malocclusion with a retrognathic mandible in a non -compliant post pubertal patient can be treated using the fixed functional appliances. One such appliance which is in common use in clinical practice today is the Forsus Fatigue Resistant Device. To treat a 13 year old female patient having a class II base, a retrognathic mandible, horizontal growth pattern, convex profile, an overjet of 7mm, mild proclination of maxillary and mandibular incisors, Class II molar and canine relationship bilaterally and a positive VTO.

Purpose: Class II patients presenting with retrognathic mandible tend to conceal their deformity by protruding the mandible forward to achieve a more esthetic profile. Thus, they present with an unstable condylar position. This study aimed to assess the post-surgical stability in mandibular advancement using presurgical versus post-surgical computer guided functional appliance.

Skeletal Class II malocclusion is attributed to maxillary prognathism, mandibular retrognathism or combination of both. In adolescent cases, the treatment includes growth modulation with headgear or myofunctional appliances. However in adults, optimum esthetic and functional efficacy can be achieved by orthodontic-surgical combination. This case report describes a 21 years old post-pubertal male with severe skeletal Class II discrepancy with normal maxilla and retrognathic mandible. The case was treated with bilateral sagittal split osteotomy (BSSO) with mandibular advancement approach. Straight profile, pleasing esthetics, bilateral Class I molar and canine relationship, normal overjet and overbite were achieved because of a combined ortho-surgical approach.

Successful airway management of an infant or child with moderate to severe retrognathia first requires recognition of a potential problem. If the child cannot be intubated in a standard fashion, the use of a laryngeal mask airway (LMA) should be considered. We describe two cases wherein a toddler and an infant with severe retrognathia failed multiple attempts at traditional intubation. Both had an anterior larynx and hypoplasia of the mandible. In both cases, a subsequent LMA was successfully placed. The severely retrognathic newborn or child presents to the physician a unique challenge in airway management. Techniques to manage this difficult pediatric airway are different from those used in the adult. Otolaryngologists should be aware of this intubation technique and include it in their armamentarium of airway-management strategies. The LMA is not recommended as the technique of choice for securing a difficult airway, but it is an effective alternative when indicated, and it might be life-saving.

Background. The Flip-Lock Herbst (TP Orthodontics Inc.) is a fixed functional appliance, a variant of the Herbst appliance, introduced by Miller. It is claimed to have better patient tolerance due to its increased freedom for the mandible’s lateral movements. There have been no studies on the flip lock Herbst till date. This study was undertaken to assess the efficiency of the Flip-Lock Herbst appliance in correcting Angle’s class II division 1 malocclusion. Methods. Eight subjects in their active growth period with class II division 1 malocclusion due to a retrognathic mandible were included in the study. Standardized lateral cephalometric radiographs were used to evaluate skeletal and dental changes with the SO analysis. Paired samples t-test was used to assess statistical significance. Results. Statistically significant increases in mandibular length (pg/OLp) and effective mandibular length (ar/OLp + pg/OLp) were observed. There was a significant maxillary restraining effect. Dental effects were significant and exhibited class II correction features except for the position of lower incisors within the mandible (ii/OLp - pg/OLp). Skeletal changes accounted for 61% and dental changes for 39% of the total treatment for molar correction. For overjet correction, skeletal changes contributed to 63% and dental changes to 37% of the total treatment. Conclusion. The Flip-Lock Herbst appliance was efficient in correcting Angle’s class II division 1 malocclusion due to a retrognathic mandible. Both skeletal and dental changes were evident, with the former predominating (60:40).

Purpose Digitalization and additive manufacturing now play an important role in the manufacturing of medical and dental products. The purpose of this paper is to present the results of the treatment of skeletal Class II malocclusion in a growing patient using fixed sagittal guidance (FSG) appliance manufactured by digital and fast procedure by selective laser melting. Design/methodology/Approach This study present the case of a 14-year-old boy with a convex profile owing to a retrognathic mandible, an overjet (8 mm), a deep overbite (7 mm), a Class II canine, a molar relationship on both sides and an accentuated lower curve of Spee. The lateral cephalogram showed a skeletal Class II discrepancy with mandibular retrognathia, skeletal deep bite, reduced lower anterior facial height and proclined upper incisors. Treatment using FSG and fixed orthodontic appliance was performed within 15 months. Findings The final results show a well-balanced face and a nice profile. Protrusion of the maxillary anterior teeth was corrected, and a Class I molar relationship was achieved with proper overjet and overbite. Research limitations/implications The results from the proposed method are promising, although long-term results with a large group are not yet available. Practical implications Using an individually made FSG appliance from biocompatible material and an individualized treatment plan, an effective result in treating Class II malocclusion due to retrognathic mandible with favorable dentofacial effects has been achieved. Originality/value This is the first paper describing the use of additive manufacturing for orthodontic appliances in Slovenia.

Introdução: Uma série de aspectos diagnósticos e terapêuticos relacionados à Sequência de Robin (SR) não possuem definição clara na literatura, conforme demonstrado em revisão sistemática presente nesta tese. Essas áreas de incerteza envolvem os métodos de classificação do grau de glossoptose por meio da endoscopia de via aérea (EVA), a associação com manifestações clínicas e a avaliação polissonográfica. Objetivos: Avaliar, a partir de um estudo transversal aninhado em uma coorte, a associação entre duas classificações de glossoptose e a severidade dos sintomas em pacientes com SR, além de determinar a acurácia dessas classificações na determinação de pacientes com maior gravidade clínica. Avaliar a associação entre parâmetros de polissonografia e graus de gravidade de manifestações clínicas. Métodos: Os pacientes com diagnóstico de SR tiveram suas manifestações clínicas classificadas conforme Cole et al. Foram submetidos à endoscopia do sono e as imagens foram classificadas de acordo com Yellon e De Sousa et al por pesquisador cegado. Os pacientes que não necessitavam de suporte ventilatório foram submetidos à polissonografia. Resultados: Os resultados obtidos foram apresentados em quatro trabalhos: Artigo 1, aceito para publicação: revisão sistemática; Artigo 2, publicado: Associação entre classificação endoscópica da glossoptose e manifestação clínica grave: neste trabalho, um total de 58 pacientes foram incluídos. A probabilidade de apresentar sintomas graves conforme classificado por Cole et al foi maior nos pacientes Yellon grau 3 (68,4%, P=0,012) e de Sousa et al moderado e grave (61,5% e 62,5%, respectivamente, P=0,015) do que nos graus mais leves de obstrução; Artigo 3, submetido: Performance diagnóstica das classificações endoscópicas: neste trabalho foram incluídos 80 pacientes. A sensibilidade (Y: 56.2% x S: 28.1%, P<0.001) e a especificidade (Y: 85.4% x S: 93.8%, P=0.038) na identificação de sintomas clínicos graves foram estatisticamente diferentes entre as classificações de Yellon e de Sousa et al. Calculou-se a Razão de Chances Diagnóstica para Yellon (RCD: 7,53 95%CI 4.15-10.90) e de Sousa (RCD: 5,87 95%CI 1.86-9.87). As diferenças encontradas não foram significativas (P=0,92); Artigo 4, submetido: Associação entre parâmetros polissonográficos e as manifestações clínicas conforme Cole et al. Determinou-se a Razão de Chances para cada variação nos seguintes parâmetros: índice de dessaturação (1.27; 1.07-1.51; R2=19.8%; P=0.006), índice de apneia e hipopneia (1.13; 1.01-1.26; R2=12.5%; P=0.02), média de saturação de oxigênio (0.16; 0.05-0.52; R2=22.6%; P=0.002), nadir de saturação (0.73; 0.56- 0.96; R2=10.0%; P=0.02), porcentagem de tempo com saturação menor que 90% (9.49; 1.63- 55.31, R2=37.6%; P=0.012) e porcentagem de tempo com obstrução (2.5; 1.31-4.76; R2=25.1%; P=0.006). Conclusões: As alterações na EVA estão associadas com a gravidade das manifestações clínicas. Ao se aprofundar a abordagem de análise sob uma perspectiva diagnóstica, demonstrou-se que as classificações de Yellon e de Sousa et al possuem uma baixa sensibilidade, porém uma alta especificidade. A porcentagem do tempo com saturação menor que 90%, porcentagem do tempo apresentando obstrução e média de saturação de oxigênio durante o sono foram os parâmetros polissonográficos com a maior associação com as manifestações clínicas. Assim, recomenda-se que a avaliação endoscópica da via aérea em pacientes portadores de SR seja realizada com intuito de estratificar a gravidade, mas não para triagem diagnóstica. Da mesma forma, recomenda-se que os parâmetros acima destacados da polissonografia, sejam especialmente considerados no acompanhamento desses pacientes.<br>Introduction: Several diagnostic and therapeutic aspects concerning Robin Sequence (RS) are not clearly defined in medical literature, as demonstrated in a systematic review included in this thesis. These areas of uncertainty comprehend methods of glossoptosis degree classification, its association with clinical manifestations and polysomnographic evaluation. Objectives: A cohort nested cross-sectional study was done to evaluate the association of two different glossoptosis classifications with symptom severity in RS patients, while determining its accuracy for the identification of severely symptomatic patients. The study also aimed to evaluate the association between polysomnographic parameters and clinical symptom severity. Methods: RS patients had their clinical manifestations classified according to Cole et al. They were also examined with flexible fiberoptic laryngoscopy (FFL) and recordings were classified according to Yellon and De Sousa et al classifications by a blinded researcher. Those patients not needing ventilator support underwent polysomnographic testing. Results: Overall results were divided into four distinct articles: Article 1, accepted for publication: systematic review; Article 2, published: Association between glossoptosis endoscopic classification and severe clinical manifestations: in this article, a total of 58 patients were enrolled. The probability of presenting severe clinical findings according to Cole et al classification was higher in patients classified as Yellon grade 3 (68.4%, P=0.012) and De Sousa et al moderate or severe levels (61.5% and 62.5%, respectively, P=0.015) than in milder degrees of obstruction. Article 3, submitted: Diagnostic performance of endoscopic classifications: in this article, additional 22 patients were enrolled, summing up 80 patients. The sensitivity (Y: 56.2% x S: 28.1%, P<0.001) and specificity (Y: 85.4% x S: 93.8%, P=0.038) in the identification of severe clinical symptoms were statistically different between classifications of Yellon and De Sousa et al. A Diagnostic Odds Ratio was computed for Yellon (DOR: 7.53 95%CI 4.15-10.90) and De Sousa et al (DOR: 5.87 95%CI 1.86-9.87). No relevant differences were found between them (P=0.92). Article 4: submitted: Association between polysomnographic parameters and obstructive airway symptoms: odds ratios for severe clinical findings were computed for the variation of polysomnographic parameters: Dessaturation Index (1.27; 1.07-1.51; R2=19.8%; P=0.006), Apnea/Hypopnea Index - AIH - (1.13; 1.01-1.26; R2=12.5%; P=0.02), Sleep Mean Oxygen Saturation (0.16; 0.05-0.52; R2=22.6%; P=0.002), Oxygen Saturation Nadir (0.73; 0.56-0.96; R2=10.0%; P=0.02), Percentage of time under oxygen saturation of 90% (9.49; 1.63-55.31, R2=37.6%; P=0.012) and Percentage of Time Presenting Obstruction (2.5; 1.31-4.76; R2=25.1%; P=0.006). Conclusions: FFL findings seem to have a fair association with the severity of clinical manifestations. However, this association was found to be probably a major influence of a high specificity, while observed sensitivity was less than would be desirable for diagnostic purposes. Percentage of time under 90% oxygen saturation, percentage of time with obstruction and mean oxygen saturation during sleep were the most associated parameters with clinical manifestations. Therefore, based on these findings, we would argue that airway endoscopic examination in RS patients should be approached aiming at clinical severity stratification, rather than for screening purposes. Also, we would recommend that those aforementioned parameters from polysomnography should be specifically addressed in the follow up of this peculiar group of patients.

Pediatric obstructive sleep apnea is an increasing major public health concern worldwide, partly resulting from the obesity epidemic which has encroached into the pediatric population. Individuals with a Class II skeletal malocclusion may suffer from snoring due to a retrognathic position of the mandible resulting in a restricted posterior pharyngeal airway space thus resulting in snoring and obstructive sleep apnea. This sleep pathology carries devastating health consequences resulting in daytime fatigue, hyperactivity and finally resulting in poor performance at school. Orthodontic therapy at an early age in OSA children may be effective in improving upper airway patency and alleviating symptoms of OSA. The twin block appliance was advocated as an efficient oral appliance for the treatment of children with OSA and mandibular retrognathia. The purpose of this chapter is to study the impact of twin block management on respiratory and biochemical parameters of Class II malocclusion children with OSA.