Search

Orthodontic camouflage provides an alternative treatment for angle III malocclusion since patients with limited economic resources cannot opt for orthognathic surgery, it being clear that correction will be achieved at the dental level and not at the bone complex. Objective: To determine an alternative treatment for patients who do not have the possibility of having orthognathic surgery. Clinical case: A 13-year-old female patient, dolico facial biotype with slightly concave profile, with Class III Skeletal by mandibular prognathism, anterior crossbite, anterior diastema, and large mandibular body, molar class, and canine III. Alexander technique brackets were placed; premolar extraction was not planned. Once the case was completed, the correction of the anterior crossbite was achieved, thanks to the use of the spaces that existed at the beginning of the treatment and also that a correct distalization of canines and retraction of the lower anterior segment were performed.

Crouzon syndrome is an autosomal dominant disorder characterized by craniosynostosis of coronal and sagittal sutures. Crouzon syndrome is caused by mutation in the fibroblast growth factor receptor-2 (FGFR-2) gene. Other characteristic features of Crouzon syndrome include exophthalmos, midfacial hypoplasia, and mandibular prognathism. The present article describes a case report of a 13-year-old male patient with characteristic skeletal and dental features of Crouzon syndrome.

Objectives: This study aimed to analyse the changes in soft tissue and hard tissue stability associated with the split pattern, i.e. long split (LS) or short split (SS), after sagittal split osteotomy., Materials and Methods: Patients who underwent sagittal split ramus osteotomy were classified into LS or SS groups according to postoperative computed tomography images. They were examined via lateral cephalography and three-dimensional (3D) optical scanning before surgery (T0) and 1 (T1), 3 (T2), and 12 (T3) months after surgery. Six standard angles (SNA, SNB, ANB, FMA, FMIA, and IMPA) were used as measures of hard tissue change. The two sets of 3D data were superimposed, and the volumetric differences were calculated as the soft tissue change. The areas evaluated were delimited by 10 × 20-mm rectangles in the frontal aspect and a 25 × 25-mm square in the lateral aspect., Results: A total of 42 sides (26 patients) were analysed, including 20 (16 patients) in the SS group and 22 (16 patients) in the LS group. We found no significant differences in cephalographic angle or soft tissue changes in the frontal aspect between the SS and LS groups. We found significant differences in the subauricular region from T0-T1 (p = 0.02), T0-T2 (p = 0.03), and T0-T3 (p = 0.037) in terms of soft tissue changes in the lateral aspect. The volume increase associated with posterior mandibular movement was greater in the LS group., Conclusions: We found that LS patients with mandibular prognathism exhibited increased subauricular volumes following mandibular setback., Clinical Relevance: It is essential to predict the postoperative facial profile before surgery. The split pattern after sagittal split osteotomy affects the postoperative profile of patients with mandibular prognathism., (© 2023. The Author(s).)

Mandibular prognathism causes functional and esthetic problems. Therefore, many studies have been conducted to understand its etiology. Following our previous study, which revealed that the major characteristic of the mandible with prognathism is the volume/length ratio of the mandibular body and condyle, we analyzed the volume and orientation of the masseter muscle, which inserts into the mandibular body, expecting that the difference in the size of the masseter muscle causes the difference in the mandibular size. This study compared the masseter muscle of the participants in the prognathic group to those in the normal group on the volume/length ratio and orientation. The masseter muscle ratios (volume/length); the angle between the superficial and deep head of the masseter muscle; and the three planes (the palatal, occlusal, and mandibular) were analyzed. A total of 30 participants constituted the normal group (male: 15, female: 15) and 30 patients, the prognathic group (male: 15, female: 15). The results showed that the volume/length ratio of the masseter of the normal group was greater than that of the prognathic group (p < 0.05). In addition, the orientation of both the superficial and deep head of the masseter of the participants in the normal group was more vertical with respect to the mandibular plane than that of the prognathic group (p < 0.05). We concluded that the mechanical disadvantage of the masseter muscle of the prognathic group is attributed to mandibular prognathism.

The purpose of this study was to evaluate the skeletal units of a normal mandible (class I) and a prognathic mandible (class III), to compare the groups, and to investigate the key functional unit responsible for mandibular prognathism. Hemi-mandibles of 101 cases were evaluated by cone-beam computed tomography. Of these, 50 cases had Class I and 51 had Class III mandibles. The length, volume, and volume/length ratio of each skeletal unit were measured. The ratios of the condyle, body unit, and sum of the hemi-mandible between Class I and Class III showed statistically significant results (P < 0.05). However, the ratios of angle, coronoid, and symphysis units did not show any statistical significance on comparison. Dependent on gender, in males the ratio of the condyle of the hemi-mandible showed statistically significant results (P < 0.05). Meanwhile in females the ratio of the body and sum of the hemi-mandible showed statistically significant results (P < 0.05). Accordingly, the mandibular body and condylar units are thinner in mandibular prognathism. On the basis of the functional matrix theory to determine the aetiology of mandibular prognathism, the key skeletal units are the body and condylar units. [ABSTRACT FROM AUTHOR]

Individuals with different functions such as the functions of the stomatognathic system (SE), such as decreased chewing capacity, phonetic alteration and aesthetic impairment. The prosthetic oral rehabilitation assumes a function of great importance for the patient with prognosis, being able to be paramount for general health and quality of life. Rehabilitation as functions of SE and reinserting the individual into the social environment. Objective: to establish a prosthetic technique performed with no intention to promote the prognosis of a person over a series of years after the creation of a conventional molding technique. Methods: This is a case report, reporting a volunteer patient who needs a new total prosthesis. Clinical and laboratory stepswere used. Results: It as found to improve the retention, stability and aesthetics of the device as an improvement in patient occlusion. Conclusion: An issue that maybe easier to correct on a large scale in the chewing and phonation functions is greater than the disadvantages to dental discrepancy of the inter-arch size present in prognostic patients. [ABSTRACT FROM AUTHOR]

A stable occlusion at the time of surgery is considered important for post-surgical stability after orthognathic surgery. The aim of this study was to determine whether skeletal stability after bimaxillary surgery using a surgery-first approach for skeletal class III deformity is related to the surgical occlusal contact or surgical change. Forty-two adult patients with a skeletal class III deformity corrected by Le Fort I osteotomy and bilateral sagittal split osteotomy with a surgery-first approach were studied. Dental models were set and used to measure the surgical occlusal contact, including contact distribution, contact number, and contact area. Cone beam computed tomography was used to measure the surgical change (amount and rotation) and post-surgical skeletal stability. The relationship between skeletal stability and surgical occlusal contact or surgical change was evaluated. No relationship was found between maxillary or mandibular stability and surgical occlusal contact. However, a significant relationship was found between maxillary and mandibular stability and the amount and rotation of surgical change. The results suggest that in the surgical-orthodontic correction of skeletal class III deformity with a surgery-first approach, the post-surgical skeletal stability is not related to the surgical occlusal contact but is related to the surgical change. [ABSTRACT FROM AUTHOR]

It has been suggested that larger species of mammals tend to become long-faced when they diverge in size during an evolutionary radiation. However, whether this allometric pattern, reminiscent of ontogenetic changes in skull proportions, is indeed a rule has yet to be thoroughly tested. Using ~ 6000 adult specimens from 14 phylogenetically well separated and ecomorphologically distinctive lineages, 11 orders, and all superorders of the placentals, I tested each group for positive craniofacial allometry (CREA). The evidence supporting CREA is overwhelming, with virtually all analyses showing proportionally longer faces in bigger species. This corroborates previous studies in other groups, consolidates CREA as a pervasive morphological trend in placental evolution and opens important research avenues for connecting micro- and macro-evolution. If found in even more lineages of non-placental mammals, confirmed in birds, and possibly discovered in other tetrapods, CREA could become one of the most general rules of morphological evolution in land vertebrates. [ABSTRACT FROM AUTHOR]

Active thumb sucking often causes malocclusion and/or facial deformity. Thumb sucking is such a detrimental habit when found in children above 6 years of age causing open bite formation, speech distortion, maxillary prognathism, posterior crossbite, mandibular retrognathism, and midline diastema. On the other hand, abnormal tongue thrusting may also cause growth disturbances of the orofacial structures and malocclusion. The present article has discussed on the management of such detrimental habits with an innovative yet a simple approach never been used before. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism. [ABSTRACT FROM AUTHOR]

Abstract Mandibular prognathism is a phenotype of facial deformity seen in populations around the world, but with higher incidence among East Asian populations. Five genome-wide nonparametric linkage analyses and a genome-wide association study to identify susceptibility loci of the phenotype have shown inconsistent results. To explore variants related to mandibular prognathism, we undertook whole-exome sequencing in a Japanese pedigree. The pedigree was ascertained as mandibular prognathism. The pedigree comprised 15 individuals from 4 generations. Four affected individuals across 2 generations and 5 unaffected individuals were chosen for whole-exome sequencing. Five non-synonymous single-nucleotide variants (SNVs) of UBASH3B , OR6M1 , OR8D4 , OR8B4 , and BEST3 genes were detected in all 4 affected individuals, but in none of the 5 unaffected individuals. A non-synonymous SNV of the BEST3 gene, Chr12(GRCh37):g.70048878G>T, NM_032735.2:c.1816C>A, p.(L606I), was identified as rare missense variant. BEST3 is located on chromosome 12q15 and encodes bestrophin 3 from the bestrophin family of anion channels. The 4 other non-synonymous SNVs of UBASH3B , OR6M1 , OR8D4 , and OR8B4 were not considered plausible candidates for mandibular prognathism. Our whole-exome sequencing implicates a rare non-synonymous SNV of BEST3 as a candidate for mandibular prognathism in the Japanese pedigree. Highlights • Whole-exome sequencing in a Japanese pedigree with mandibular prognathism was done. • Five non-synonymous single-nucleotide variants (SNVs) were identified. • A non-synonymous SNV (p.L606I) of BEST3 gene was a novel missense variant. • The sequencing implicates the variant as a candidate for mandibular prognathism. [ABSTRACT FROM AUTHOR]

Mandibular prognathism is characterized by a prognathic or prominent mandible. The objective of this study was to find the gene responsible for mandibular prognathism. Whole exome sequencing analysis of a Thai family (family 1) identified the ADAMTSL1 c.176C>A variant as the potential defect. We cross‐checked our exome data of 215 people for rare variants in ADAMTSL1 and found that the c.670C>G variant was associated with mandibular prognathism in families 2 and 4. Mutation analysis of ADAMTSL1 in 79 unrelated patients revealed the c.670C>G variant was also found in family 3. We hypothesize that mutations in ADAMTSL1 cause failure to cleave aggrecan in the condylar cartilage, and that leads to overgrowth of the mandible. Adamtsl1 is strongly expressed in the condensed mesenchymal cells of the mouse condyle, but not at the cartilage of the long bones. This explains why the patients with ADAMTSL1 mutations had abnormal mandibles but normal long bones. This is the first report that mutations in ADAMTSL1 are responsible for the pathogenesis of mandibular prognathism. Mandibular prognathism is characterized by a prognathic or prominent mandible. The objective of this study was to find the gene responsible for mandibular prognathism. We report the first ADAMTSL1 mutations that cause isolated mandibular prognathism. The mode of inheritance is autosomal dominance with incomplete penetrance. It is hypothesized that mutations of ADAMTSLI cause failure in aggrecan cleavage and subsequent overgrowth of the mandible due to the increase in the size of the condylar cartilaginous template. [ABSTRACT FROM AUTHOR]

Copyright of Orthodontie Française is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the case study of an 11-year-old girl with impacted teeth. The patient's clinical examination results are discussed including mild left facial asymmetry, frontal bossing, and mild mandibular prognathism. The patient was diagnosed with nevoid basal cell carcinoma syndrome consisting of odontogenic keratocysts (OKCs) and bifid ribs, and underwent marsupialization or decompression followed by enucleation to manage OKCs.

Abstract Important aspects of orthognathic surgery are the effects of skeletal movement and changes in the position of the hyoid bone, tongue, soft palate, and dimensions of the pharyngeal airway. Our aims were to evaluate the 3-dimensional changes in the pharyngeal airway and in the position of the hyoid bone after mandibular setback in 30 patients who were diagnosed with mandibular prognathism and were treated by intraoral vertical ramus osteotomy (IVRO). Three-dimensional cone-beam computed tomographic (CT) images were obtained preoperatively, one month postoperatively, and one year postoperatively. The total pharyngeal volume decreased between the preoperative state and one month and one year afterwards. The hyoid bone had moved 2.0 mm posteriorly and 3.15 mm superiorly by one month postoperatively. The position of the hyoid bone was affected by changes in posterior and superior movement of the B point at one month (r = 0.44, p = 0.015 and R = 0.63, p = 0.000, respectively) and also by superior movement of the B point at one year (r = 0.57, p = −0.001). There was an advantageous relation between posterior positional changes in the B point (mandibular setback), and volumetric changes in the hypopharyngeal and total pharyngeal airway, so maxillofacial surgeons should consider the reduction in airway when planning excessive mandibular setback. [ABSTRACT FROM AUTHOR]

Background. This study investigates the differences in the lateral profile and frontal appearance after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) procedures for the correction of mandibular prognathism. Methods. Sixty patients (30 SSRO and 30 IVRO) underwent mandibular setback surgery. Serial cephalograms were obtained: (1) T1: approximately 1 month before surgery; (2) T2: at least 6 months after surgery for SSRO and at least 1 year after surgery for IVRO. The landmarks, linear distances, and related angles were measured. The t-test was applied to the intragroup and intergroup comparisons. The null hypothesis was that SSRO and IVRO made no difference in the facial appearance. Results. In the IVRO group, the ramus and gonial widths significantly decreased by 3.9 mm and 5.8 mm, respectively. SSRO significantly reduced the gonial angle by 2.6°, and IVRO increased it significantly by 5.3°. The postoperative increases at frontal bone levels 0 and 1 after IVRO were significantly larger than those after SSRO, but, at level 3, the increases after SSRO were larger than those after IVRO. In the frontal muscular and facial planes, SSRO and IVRO presented no difference. The frontal jaw angle and face angle were significantly larger with IVRO than with SSRO. Therefore, the null hypothesis was rejected. Conclusions. The ramus width and gonial width were significantly decreased in IVRO compared to SSRO. IVRO increased angles in the lateral profile (gonial angle and mandibular plane angle) and frontal appearance (jaw angle and face angle) more than SSRO did. [ABSTRACT FROM AUTHOR]

That great ape endocranial shape development persists into adolescence indicates that the splanchnocranium succeeds brain growth in driving endocranial development. However, the extent of this splanchnocranial influence is unknown. We applied two-block partial least squares analyses of Procrustes shape variables on an ontogenetic series of great ape crania to explore the covariation of the endocranium (the internal braincase) and splanchnocranium (face, or viscerocranium). We hypothesized that a transition between brain growth and splanchnocranial development in the establishment of final endocranial form would be manifest as a change in the pattern of shape covariation between early and adolescent ontogeny. Our results revealed a strong pattern of covariation between endocranium and splanchnocranium, indicating that chimpanzees, gorillas, and orangutans share a common tempo and mode of morphological integration from the eruption of the deciduous dentition onwards to adulthood: a reflection of elongating endocranial shape and continuing splanchnocranial prognathism. Within this overarching pattern, we noted that species variation exists in magnitude and direction, and that the covariation between the splanchnocranium and endocranium is somewhat weaker in early infancy compared to successive age groups. When correcting our covariation analyses for allometry, we found that an ontogenetic signal remains, signifying that allometric variation alone is insufficient to account for all endocranial-splanchnocranial developmental integration. Finally, we assessed the influence of the cranial base, which acts as the interface between the face and endocranium, on the shape of the vault using thin-plate spline warping. We found that not all splanchnocranial shape changes during development are tightly integrated with endocranial shape. This suggests that while the developmental expansion of the brain is the main driver of endocranial shape during early ontogeny, endocranial development from infancy onwards is moulded by the splanchnocranium in conjunction with the neurocranium. [ABSTRACT FROM AUTHOR]

Mandibular prognathism (MP) is regarded as a craniofacial deformity resulting from the combined effects of environmental and genetic factors, while the genetically predetermined component is considered to play an important role to develop MP. Although linkage and association studies for MP have identified multiple strongly associated regions and genes, the causal genes and variants responsible for the deformity remain largely undetermined. To address this, we performed targeted sequencing of 396 genes selected from previous studies as well as genes and pathways related with craniofacial development as primary candidates in 199 MP cases and 197 controls and carried out a series of statistical and functional analyses. A nonsynonymous common variant of MYO1H rs3825393, C>T, p.Pro1001Leu, was identified to be significantly associated with MP. During zebrafish embryologic development, expression of MYO1H orthologous genes were detected at mandibular jaw. Furthermore, jaw cartilage defects were observed in zebrafish knockdown models. Collectively, these data demonstrate that MYO1H is required for proper jaw growth and contributes to MP pathogenesis, expanding our knowledge of the genetic basis of MP. [ABSTRACT FROM AUTHOR]

The article deals with the use of occlusal therapy in selected cases to halt the progression of gingival clefts due to occlusal trauma, and to repair the marginal cleft. It enumerates the advantages of the therapy, including conservation of the tooth tissue and preservation of vertical dimension. It notes the goal of protrusive grinding which is the elimination of posterior toot contact, with all contact occurring on the anterior teeth. It describes how little centric slide will be corrected after the completion of lateral excursions.

The article discusses the differential diagnosis and early treatment of the general categories of Class II patient. When teeth are in Class II relationship, maxillary aveolodental protrusion occurs. Other Class II relationships conditions include mandibular retrognathism and maxillary skeletal prognathism. Early treatment of Class II patient is described as the management of the occlusion and skeletal pattern before most of the permanent dentition has erupted. In addition, early Class II treatment lets dentists maximize the advantage of growth, improve skeletal patterns and correct the relationship between the maxilla and mandible.

This article promotes preprosthetic surgery that has been adequately planned and properly executed and that is an integral part of a comprehensive treatment plan. In addition, this paper promotes the development of preprosthetic surgery teams to select, plan, and treat preprosthetic surgery patients. Prosthodontists should take a more active role in the referral, selection, and treatment planning of preprosthetic surgery patients, because it is the prosthodontist who will restore the patient's dentition. Prosthodontists and surgeons need a greater understanding of each other's capabilities and limitations, and need to work together as a team. [ABSTRACT FROM AUTHOR]

The article discusses the effects of several dental abnormalities including anterior open bite, mandibular prognathism, and clefts of the lip and palate on the speech production. It is reported that an anterior open bite is a condition where maxillary anterior teeth leaves a hiatus between mandibular and maxillary anterior teeth when it do not cover mandibular anterior teeth and its effect on speech production depends on degree of prognathism of mandible or maxilla. Maxillary protrusion allows inadequate space for the tongue to be enclosed within the mandible limits because of which tongue is compelled to protrude the mandibular incisors. As cited, cleft lip disrupts the phonemes that involve the upper lip whereas in cases of palatal clefts speech can be practically broken.

The article provides information on the causes of facial developmental deformities. It discusses the types of maxillo-facial malformations that differ from the characteristics of facial developmental deformity, including congenital deformities, acquired deformities and deformities due to temporo-mandibular ankylosis, and the causes of these malformations. It also discusses the original concept of the terms "retrognathism" and "prognathism." Details on how to get rid of facial deformities are provided.

The purpose of this study was to determine the position of the mandibular canal in relation to the buccal cortical bone in Chinese patients with three dentofacial relationships: normal dentition, retrognathism, and prognathism. Methods: Cone-beam computed tomography and lateral cephalograms of patients with normal dentation, retrognathism, and prognathism (n = 32 each group) were reviewed. Measurements of the shortest distance from the outer/buccal edge of the mandibular canal to the inner surface of the buccal cortex, and the distance from the lingula of the ramus to the dorsal root of the first molar were recorded. Results: No significant difference was observed between the three groups in the distribution of contact or fusion of the mandibular canal, or in the course of the mandibular canal on the right or left side. When the shortest distance at the lingula on the left side was >2.1 mm, no instances of contact or fusion were observed. On the right side, 100% of the patients had no contact or fusion when the shortest distance was >2.7 mm at the lingula. Conclusion: The shortest distance from the outer/buccal edge of the mandibular canal to the inner surface of the buccal cortex measured at the lingula can predict contact or fusion. During sagittal split ramus osteotomy, great care should be observed at the point halfway between the lingula and the anterior ramus border where the inferior alveolar nerve is the closest to the cortical bone.

Background/Aim. Postoperative condylar position is a substantial concern in surgical correction of mandibular prognathism. Orthognathic surgery may change condylar position and this is considered a contributing factor for early skeletal relapse and the induction of temporomandibular disorders. The purpose of this study was to evaluate changes in condylar position, and to correlate angular skeletal measurements following bimaxillary surgery. Methods. On profile teleradiographs of 21 patients with mandibular angular and linear parametres, the changes in condylar position, were measured during preoperative orthodontic treatment and 6 months after the surgical treatment. Results. A statistically significant difference in values between the groups was found. The most distal point on the head of condyle point (DI) moved backward for 1.38 mm (p = 0.02), and the point of center of collum mandibulae point (DC) moved backward for 1.52 mm (p = 0.007). The amount of upward movement of the point DI was 1.62 mm (p = 0.04). Conclusion. In the patients with mandibular prognathism, the condyles tend to migrate upward and forward six months after bimaxillary surgery.

Orthognathic surgery alters the position of maxilla and mandible, and consequently changes the nasal shape. The nasal change remains a concern to Asian patients. The aim of this study was to measure the nasal changes using a novel three-dimensional photographic imaging method. Methods: A total of 38 patients with Class III malocclusion and prognathism were enrolled. All patients underwent two-jaw surgery with the standard technique. A nasal alar cinching suture was included at the end of procedure. Facial landmarks and nasal morphology were defined and measured from pre- and postoperative three-dimensional photographic images. Intra-rater errors on landmark identification were controlled. Patient's reports of perceptual nasal changes were recorded. Results: The average width of the alar base and subalare remained similar after surgery. Alar width was increased by 0.74 mm. Nasal height and length remained the same. Nasolabial angle increased significantly. The area of nostril show revealed a significant increase and was correlated with a decrease of columella inclination. Nasal tip projection decreased significantly, by 1.99 mm. Preoperative nasal morphology was different between patients with and without cleft lip/palate, but most nasal changes were concordant. In the self-perception, 37% of patients reported improved nasal appearance, 58% reported no change, and 5% were not satisfied with the nasal changes. Conclusion: After the surgery, characteristic nasal changes occurred with an increase of nasolabial angle and nostril show, but a preserved nasal width. The majority of patients did not perceive adverse nasal changes.

A 49-year-old patient presented with an Angle Class III malocclusion with a partially edentulous mandible, as diagnosed by orofacial examination and radiographic and cephalometric analyses. The patient refused orthognathic surgery; therefore, the treatment plan included the preparation of all teeth and fabrication of provisional restorations to reestablish optimal occlusion. To allow for the placement of 3 implants, the edentulous posterior mandibular ridge was improved via alveolar distraction. The patient was recalled 3, 6, 12, and 24 months after prosthodontic treatment. The oral situation was stable and patient satisfaction was reported as high. [ABSTRACT FROM AUTHOR]

MED12 is a member of the large Mediator complex that controls cell growth, development, and differentiation. Mutations in MED12 disrupt neuronal gene expression and lead to at least three distinct X‐linked intellectual disability syndromes (FG, Lujan‐Fryns, and Ohdo). Here, we describe six families with missense variants in MED12 (p.(Arg815Gln), p.(Val954Gly), p.(Glu1091Lys), p.(Arg1295Cys), p.(Pro1371Ser), and p.(Arg1148His), the latter being first reported in affected females) associated with a continuum of symptoms rather than distinct syndromes. The variants expanded the genetic architecture and phenotypic spectrum of MED12‐related disorders. New clinical symptoms included brachycephaly, anteverted nares, bulbous nasal tip, prognathism, deep set eyes, and single palmar crease. We showed that MED12 variants, initially implicated in X‐linked recessive disorders in males, may predict a potential risk for phenotypic expression in females, with no correlation of the X chromosome inactivation pattern in blood cells. Molecular modeling (Yasara Structure) performed to model the functional effects of the variants strongly supported the pathogenic character of the variants examined. We showed that molecular modeling is a useful method for in silico testing of the potential functional effects of MED12 variants and thus can be a valuable addition to the interpretation of the clinical and genetic findings. [ABSTRACT FROM AUTHOR]

Abstract Transoral vertical ramus osteotomy (VRO) has been condemned because the condyle has the potential to sag, and because it needs lengthy maxillomandibular fixation. We have therefore introduced a simple method of fixation, and examined its effectiveness and complications. After the osteotomy, the proximal and distal segments are trimmed to adapt to each other. Four Kirschner (K) pins 0.9 mm in diameter are inserted percutaneously from the proximal to the distal segment while the condyle is positioned in the glenoid fossa. This is followed by a brief period of maxillomandibular fixation. We have reviewed the records of 95 patients who had unilateral or bilateral vertical ramus osteotomy fixed with K pins, after which the mean (SD) period of fixation was 19 (11) days. Fixation failed in two patients because excursion of the jaw was either too heavy or too early. The fixations were redone. All other fixations remained stable, including the 20 dual-jaw procedures in which VRO preceded maxillary osteotomy. The mean (SD) maximal mouth opening at final follow-up was 44 (7) mm, and in only one patient was it less than 30 mm. Numbness of the lip or chin developed in seven patients, five of whom had other anterior mandibular procedures. Four patients had discomfort on palpation of the site of the pins, and one required removal. The new method was effective, and resulted in few complications within its limitations. [ABSTRACT FROM AUTHOR]

Background: A number of authors have suggested that there is close relationship between the facial form and also profile shape with Class I, II, and III malocclusion. Malocclusion is a morphological variation among individual that can be associated with the pathological condition in some cases. It is has the long last implication to the facial form and profile shape due to overbite and overjet condition. The most common malocclusion is Class I malocclusion in which the individual generally has mesocephalic head shape and straight facial profile. Aim: The scope of the research was to study the correlation between facial form and profile shape and in patients with Class I, II, and II malocclusion. Materials and Methods: A total of 18 subjects were recruited in this study that having malocclusions age ranging from 18 to 60 years. All the subjects were clinically examined for different types of malocclusion. The facial form and profile shape were assessed by viewing from the superficial facial features from the subject's coronal and sagittal side, respectively. Result: 11 out of the total subjects were having Class l, the majority of them were mesoprosopic (82%), and both euryprosopic and leptoprosopic had equally 9% each. For Class II, 25% were euryprosopic and 75% were mesoprosopic. There was no significant subject having leptoprosopic facial morphology in Class II. Facial index in Class III show majority of leptoprosopic facial index (75%) followed by mesoprosopic with the percentage of 33. According to the gender, it was that both sexes had equivalence in molar Class II. Conclusion: The face and skeletal morphology does have a specific type of dental malocclusion, which can be related to the attribution of germ layer during growth development. This is in concordance to the result that subjects with mesoprosopic facial type have more likely to have Class I and Class I dental malocclusion. [ABSTRACT FROM AUTHOR]

In a previous genome-wide association study, plexin A2 (PLXNA2) was suggested as one of the candidate genes for mandibular prognathism. PLXNA2 encodes plexin A2, a member of the plexin-A family of semaphorin co-receptors. Semaphorin 3A (sema3A) exerts an osteoprotective effect. However, to the best of our knowledge, there have been no previous studies examining the role of sema3A or plexin A2 on human chondrocytes. The objectives of the present study were to examine the function of sema3A and its receptor, plexin A2, in human chondrocytes. Normal human chondrocytes were cultured in media with either a high (100 ng/ml) or a low (1 ng/ml) concentration of sema3A, or without sema3A as a control. Cells and extracellular matrices were assayed for concentrations of protein and parathyroid hormone-related peptide receptor 1 (PTH-R1) using a bicinchoninic acid assay and an enzyme immunoassay, respectively. At culture day 7, the high and low concentrations of exogenous sema3A significantly increased the protein content compared with the control (P=0.0008 and 0.00002, respectively). At culture day 14, a high concentration of exogenous sema3A significantly increased the protein content and decreased the concentration of PTH-R1 compared with the control (P=0.002). The present study revealed novel results that exogenous sema3A suppresses the expression of PTH-R1 in human proliferative chondrocytes and suggested that sema3A may affect human chondrocytes via its receptor, plexin A2. [ABSTRACT FROM AUTHOR]

This study was designed to introduce and evaluate the clinical use of a surgical guide and a CAD/CAM prebent titanium plate for sagittal split ramus osteotomy (SSRO) in the correction of mandibular prognathism. We studied 14 patients who had been diagnosed, and treated by bilateral SSRO with the guide, during the period July 2015–January 2016. Surface deviations of distal segments from simulation until the end of the operation were measured on a coloured map. Deviations of position and orientation of the condyle and proximal segment from before to after operation, and those from simulation until the end of the operation, were measured with a 3-dimensional vector. All patients were followed up for at least a year. The coloured map showed that the mean (SD) distances were 0.40 (0.25) mm between the simulated and postoperative distal segments. The 3-dimensional vector showed that the mean values of mediolateral, anteroposterior, and superior-inferior translations of the condyles were less than 1 mm (p < 0.02) from before the operation until the end, and from simulation to the end of the operation, and the mean value of pitching for proximal segments was less than 1° (p < 0.02) from simulation to the end of the operation. At the one year follow-up, the occlusions were stable. Based on accurate diagnosis and simulation, this guide takes the distal segment precisely to its planned position, and the condyle and proximal segment are well-controlled. This is a useful tool, which is comparatively easy to make and operate. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography. Materials and Methods: The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test. Results: The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients. Conclusion: The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively. [ABSTRACT FROM AUTHOR]

Both deep understanding and reliable prediction of postoperative soft tissue changes are crucial for planning orthognathic surgery. Instead of estimating soft tissue responses by measuring individual landmark changes, this study aimed to investigate the relationship (ratio) between soft and hard tissue movements in different facial regions through three-dimensional cone-beam computed tomography (CBCT). Preoperative and postoperative CBCT images were superimposed using the surface registration method on the basis of the cranial base, and 10 facial regions of interest were defined. Region-based volumetric subtractions between the preoperative and postoperative segments were performed. The volumetric differences and surface of each region were used to estimate the average movement. Correlation and regression analyses were performed to examine the relationships between the corresponding soft and hard tissue movements. An overall pattern of facial soft tissue movement was observed in patients with prognathism who underwent orthognathic surgery. The experiment results have shown that mean ratios for the average soft-to-hard tissue movements in the facial regions varied, which may not exactly be similar to the published reports because of the population biocharacteristics and study methods, but the trend is in agreement with the previous studies. Additionally, the prediction capability of the regression model was significantly high, ranging from 0.786 to 0.857, in upper lip, upper vermilion, and chin regions, thus demonstrating that the skin outline changes in these critical regions could be reliably predicted from the underlying bone movements. These results could likely be applied in future soft tissue simulation in orthognathic surgery. [ABSTRACT FROM AUTHOR]

This study investigated 36 patients at 10–15 years after they had undergone mandibular setback surgery by intraoral vertical ramus osteotomy (IVRO) and subsequent intermaxillary fixation for 6 weeks. The patients completed a 37-item structured questionnaire to evaluate patient satisfaction and possible long-term effects of the treatment. Visual analogue scales were used to measure self-perceived changes in seven items concerning oral function and appearance. Oral health-related quality of life was assessed using the Oral Impacts on Daily Performance (OIDP) index. The main reasons for seeking treatment were to improve chewing function and appearance. The treatment had resulted in significant improvements regarding chewing function, appearance, bullying, and self-confidence in social settings (all P < 0.05). All patients were either very satisfied (61%) or reasonably satisfied (39%) with the treatment result. The mean OIDP frequency score was 8.49 on a scale from 8 to 40. Seventy-four percent of the patients reported no oral impacts on quality of life. In conclusion, 10–15 years after combined orthodontic and IVRO surgical treatment of mandibular prognathism, the patients were satisfied, and oral health-related quality of life was reported to be good. [ABSTRACT FROM AUTHOR]