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Smith-Magenis Syndrome—A Developmental Disorder with Circadian Dysfunction
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
Ann C.M. Smith, Wallace C. Duncan
Craniofacial features in SMS are distinct across all ages (Fig. 2), but often subtle during infancy. The head is brachycephalic with a square-shaped face and prominent forehead. The eyes are close and deep set with upslanting palpebral fissures. Although the marked midface hypoplasia persists across all ages, it may not be fully appreciated in early infancy. In the infant/toddler stage, children with SMS have a smiling, almost angelic (cherubic) appearance, due to their rosy and pudgy cheeks, marked midface hypoplasia, and upslanting palpebral fissures. Their facial features have been described as reminiscent of the Hummel porcelain angel figurines. Eyebrows are usually heavy and dark with mild to complete synophrys that becomes more apparent with age. The nose is short (reduced nasal height) and broad with anteverted nares. The face may appear expressionless with an open mouth posture. The mouth is very distinct and characteristic of the syndrome, especially at younger ages. The upper lip is down-turned with a cupid’s bow or “tented” appearance. Micrognathia changing to relative prognathism occurs with age. In a few instances, the micrognathia may lead to a clinical diagnosis of Pierre Robin sequence with/ without associated cleft palate (2,26). The facial appearance is most distinctive by mid-childhood (school age) and appears to coarsen with age (Fig. 2). The midface hypoplasia persists into adulthood, and the lower jaw grows, becomes more angulated and exhibits relative prognathia (56).
Macroglossia
Published in Prem Puri, Newborn Surgery, 2017
Thambipillai Sri Paran, George G. Youngson
If treatment is inappropriately delayed, protracted dental defects develop, including prognathism, anterior open bite, and an increased angle between the ramus and body of the mandible.9 Speech defects occur, and articulation is subsequently defective, especially expression of consonants, which are precluded by inadequate tongue movement as a consequence of the increased bulk in a limited cavity. Regression of macroglossia is not a regular feature when due to lymphangioma, and a conservative approach to the lesion has little merit.
Neuroendocrine disease
Published in Philip E. Harris, Pierre-Marc G. Bouloux, Endocrinology in Clinical Practice, 2014
Clinical features may relate primarily to the somatic overgrowth engendered by elevated GH and IGF-I levels, to the size of the tumor itself, and/or due to symptoms of associated hypopituitarism. Key features of the condition relate to the somatic overgrowth that results in the characteristic symptoms (Table 1.12) and signs (Table 1.13) of acromegaly. Frequently, the features can best be appreciated by retrospective comparison of the patient’s photographs (Figure 1.22). Thickening of the skin is a cardinal physical sign. This thickening can be objectively demonstrated by the measurement of heel pad thickness on x-ray. As a result, venipuncture is often difficult. Skin cuts tend to heal quickly. Patients frequently describe excessive sweating and greasy skin. Skin tags are a common feature, particularly in the axilla and around the nape of the neck. Glossomegaly is also a cardinal sign. The glossomegaly can interfere with mastication that is exacerbated by prognathism and dental malocclusion.
Comparison of stress distribution of TMJ with different mandibular deformities under incisal clenching
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Annan Li, Bingmei Shao, Zhan Liu
A total of 34 individuals over 18 years old from the Affiliated Hospital of Stomatology of Chongqing Medical University were involved in this study, including 10 asymptomatic subjects (four females and six males, 26.7 ± 4.8 years old) as the control group, 10 patients with mandibular prognathism (seven females and three males, 23.6 ± 3.2 years), five patients with mandibular retrusion (five females and zero male, 29.2 ± 11.6 years) and nine patients with mandibular deviation (four females and five males, 22.4 ± 4.1 years). All the subjects were from the clinical cases without artificial selections. Each participant signed an informed consent agreement. The lower incisors of the subjects with mandibular prognathism were in front of the upper incisors. As for the subjects with mandibular retrusion, the lower incisor tips were behind the root of the upper incisors. If the mandibular midline deviation from facial midline is more than 3 mm, the patient is considered as having mandibular deviation. According to the previous studies (Ueki et al. 2000), for the patients with mandibular deviation to one side, this side was considered as the non-deviated side while the other side was considered as the deviated side.
Establishment of a novel method for qualitative and quantitative evaluation of deglutitive tongue movement by integration of ultrasound video imaging and lateral cephalogram
Published in Orthodontic Waves, 2021
Thiri Hla-Myint, Michiko Tsuji, Shoichi Suzuki, Naoto Obayashi, Tohru Kurabayashi, Keiji Moriyama
The tongue is considered to have an impact on the position of the teeth and the morphology of the dental arch in the oral cavity. This can be attributed to its volume, position and movement [1,2]. Previous papers have reported that the tongue was low postured, and the tongue tip was situated more anteriorly in patients with mandibular prognathism than in those with normal occlusion [3,4]. Besides, Primozic has reported on the substantially greater mandibular inter-molar width and the smaller maxillary inter-canine width in Class III malocclusion [5]. These characteristic shapes of the dental arch might be compensated for the aspects of tongue position and movement in patients with Class III malocclusion. Patients with mandibular prognathism often undergo surgical orthodontic treatment for the improvement of facial morphology and occlusion. Wickwire et al. speculated that the tongue position and/or function compensated for the changes in the oral environment by adaptation of the tongue to the morphology of the remodelled oral cavity [6]. Investigation of adaptation of the tongue position and movement to the morphological changes of oral cavity could provide valuable information for post-surgical treatment to attain occlusal stability. For example, myofunctional therapy may prove beneficial during post-surgical orthodontic treatment planning in patients with a less adapted tongue movement to the remodelled oral cavity [7].
Effect of sagittal split ramus osteotomy on stress distribution of temporomandibular joints in patients with mandibular prognathism under symmetric occlusions
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Hedi Ma, Jingheng Shu, Quanyi Wang, Haidong Teng, Zhan Liu
Mandibular prognathism affects the facial appearance and quality of daily life negatively. It was reported that mandibular prognathism alone accounted for 43% of all mandibular deformities (Tsang et al. 1998). Sagittal split ramus osteotomy (SSRO) is the representative orthognathic surgery for patients with mandibular prognathism (Fang et al. 2007). However, postoperative complications, such as skeletal relapse, condylar absorption, and temporomandibular joint disorder (TMD), are found to occur (Martis et al. 1984; Mitsukawa et al. 2013). Inappropriate condylar positioning can lead to postoperative complications (Rebellato et al. 1999). Biomechanical studies have demonstrated that postoperative complications are related to changes in stresses in the postoperative osteotomy area and the temporomandibular joint (TMJ) (Ueki et al. 2006). Condylar positioning is related to joint spaces. The reduction in joint spaces can lead to the squeezing of the articular disc, leading to an increase in the stress levels in the TMJ and osteoarthritis (Zhang et al. 2018). This in turn may cause pain in the joint and other symptoms of TMD. Thus, it is essential to understand the biomechanical environment of TMJ to analyse the effects of SSRO on mandibular prognathism patients.