Long-term Skeletal Changes Research Articles

Is Orthognathic Correction with TMJ Preservation A Stable Treatment Option for Patients with Juvenile Idiopathic Arthritis?

The purpose of this study was to evaluate the long-term skeletal stability of orthognathic correction of dentofacial deformities secondary to juvenile idiopathic arthritis (JIA) in individuals without total alloplastic joint reconstruction. The investigators designed and implemented a retrospective case series of patients diagnosed with JIA who underwent bimaxillary orthognathic surgery. To evaluate the long-term skeletal changes, the maxillary palatal plane to mandibular plane angle, anterior facial height, and posterior facial height measurements were evaluated through cephalograms. Six patients met inclusion criteria. All subjects were female (mean 16.2years). Four patients demonstrated < 1° of change of the palatal plane to mandibular plane angle, and all patients had < 2° of change. Three patients had < 1% change in the anterior to posterior facial height ratio. Three patients demonstrated relative posterior facial shortening compared to anterior facial height (< 4%). No patients developed postoperative anterior open-bite malocclusion. Orthognathic correction of the JIA DFD deformity with TMJ preservation is a viable modality to improve facial esthetics, occlusion, upper airway and speech swallowing and chewing mechanisms in select patients. The measured skeletal relapse did not affect the clinical outcome.

Unilateral cervical spinal cord injury induces bone loss and metabolic changes in non-human primates (Macaca fascicularis).

Background/ObjectiveThe deleterious effects of chronic spinal cord injury (SCI) on the skeleton in rats, especially the lower extremities, has been proved previously. However, the long-term skeletal changes after SCI in non-human primates (NHP) have been scarcely studied. This study aimed to evaluate the bone loss in limbs and vertebrae and the bone metabolic changes in NHP after unilateral cervical spinal cord contusion injury.MethodsTwelve Macaca fascicularis were randomly divided into the SCI (n=8) and the Sham (n=4) groups. The SCI models were established using hemi-contusion cervical spinal cord injury on fifth cervical vertebra (C5), and were further evaluated by histological staining and neurophysiological monitoring. Changes of bone microstructures, bone biomechanics, and bone metabolism markers were assessed by micro-CT, micro-FEA and serological kit.ResultsThe NHP hemi-contusion cervical SCI model led to consistent unilateral limb dysfunction and potential plasticity in the face of loss of spinal cord. Furthermore, the cancellous bone mass of ipsilateral humerus and radius decreased significantly compared to the contralateral side. The bone volume fraction of humerus and radius were 17.2% and 20.1% on the ipsilateral while 29.0% and 30.1% on the contralateral respectively. Similarly, the thickness of the cortical bone in the ipsilateral forelimbs was significantly decreased, as well as the bone strength of the ipsilateral forelimbs. These changes were accompanied by diminished concentration of osteocalcin and total procollagen type 1 N-terminal propeptide (t-P1NP) as well as increased level of β-C-terminal cross-linking telopeptide of type 1collagen (β-CTX) in serological testing.ConclusionsThe present study demonstrated that hemi-SCI induced loss of bone mass and compromised biomechanical performance in ipsilateral forelimbs, which could be indicated by both muscle atrophy and serological changes of bone metabolism, and associated with a consistent loss of large-diameter cells of sensory neurons in the dorsal root ganglia.The Translational potential of this ArticleOur study, for the first time, demonstrated the bone loss in limbs and vertebrae as well as the bone metabolic changes in non-human primates after unilateral spinal cord injury (SCI). This may help to elucidate the role of muscle atrophy, serological changes and loss of sensory neurons in the mechanisms of SCI-induced osteoporosis, which would be definitely better compared with rodent models.

Long-term Bone Loss and Deterioration of Microarchitecture After Gastric Bypass in African American and Latina Women.

The prevalence of obesity is burgeoning among African American and Latina women; however, few studies investigating the skeletal effects of bariatric surgery have focused on these groups. To investigate long-term skeletal changes following Roux-en-Y gastric bypass (RYGB) in African American and Latina women. Four-year prospective cohort study. African American and Latina women presenting for RYGB (n = 17, mean age 44, body mass index 44 kg/m2) were followed annually for 4 years postoperatively. Dual-energy x-ray absorptiometry (DXA) measured areal bone mineral density (aBMD) at the spine, hip, and forearm, and body composition. High-resolution peripheral quantitative computed tomography measured volumetric bone mineral density (vBMD) and microarchitecture. Individual trabecula segmentation-based morphological analysis assessed trabecular morphology and connectivity. Baseline DXA Z-Scores were normal. Weight decreased ~30% at Year 1, then stabilized. Parathyroid hormone (PTH) increased by 50% and 25-hydroxyvitamin D was stable. By Year 4, aBMD had declined at all sites, most substantially in the hip. There was significant, progressive loss of cortical and trabecular vBMD, deterioration of microarchitecture, and increased cortical porosity at both the radius and tibia over 4 years. There was loss of trabecular plates, loss of axially aligned trabeculae, and decreased trabecular connectivity. Whole bone stiffness and failure load declined. Risk factors for bone loss included greater weight loss, rise in PTH, and older age. African American and Latina women had substantial and progressive bone loss, deterioration of microarchitecture, and trabecular morphology following RYGB. Further studies are critical to understand the long-term skeletal consequences of bariatric surgery in this population.

Long-Term Skeletal Changes After Maxillary Distraction Osteogenesis in Growing Children With Cleft Lip/Palate.

To systematically evaluate the skeletal changes after maxillary distraction osteogenesis (DO) in growing patients with cleft lip with or without cleft palate (CL/P). Electronic databases, gray literature, and reference list searches were conducted. Articles reporting prospective and retrospective studies that included patients <16 years old (N ≥ 6) who had received DO surgery for correction of a midfacial hypoplasia due to CL/P, and the period of follow-up persisted >1 year were reviewed. The original articles were evaluated by 2 investigators to ensure that they met the selection criteria. A methodologic quality assessment tool was used to evaluate the quality of selected studies. Twenty-six studies met the initial search criteria, and 9 articles included 101 growing patients with maxillary hypoplasia due to CL/P who received DO surgery were finally selected and analyzed. The results showed that long term after maxillary advancement with DO, the horizontal relapse in A-point was <15% in 3 studies, 20% to 25% in 1 study, 30% to 35% in 3 studies, and >40% in 1 study. Totally, the range of horizontal relapse in A-point was 11.9% to 45.9%. Similarly, the relapse in SNA angle was <30% in 1 study, 30% to 40% in 3 studies, and >40% in 2 studies. Totally, the range of relapse in SNA was 25.7% to 77%. Two studies showed that the vertical relapse in A-point were 137% and 208%, and in the PNS point were 65% and 62.7%. Although findings demonstrated that DO is an effective treatment method for severe maxillary hypoplasia in growing patients with CL/P, there is a relatively high amount of skeletal relapse both in horizontal and vertical dimension. Thus, the first proposed alternative for CL/P patients would be to select the correct primary procedure to decrease damage and avoid unnecessary scars. Then appropriate preoperative and postoperative care is necessary to prevent postoperative relapse. In addition, overcorrection also may be a possible alternative for compensation of postoperative relapse.

A comprehensive study of long-term skeletal changes after spinal cord injury in adult rats.

Spinal cord injury (SCI)-induced bone loss represents the most severe osteoporosis with no effective treatment. Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae, and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography (µCT), micro-finite element, histology, and serum biochemical analyses. At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.

Long-term Skeletal Changes with Rapid Maxillary Expansion: A Review of the Literature

Evidence-based dentistry is currently a high priority in the clinical practice of orthodontics. Treatment decisions are made using evidence-based information whenever it is available to the clinician. The focus of this article is to evaluate the current literature available on the long-term stability of rapid maxillary expansion. The literature was reviewed from 1979 to 2009, and all systematic reviews and meta-analyses were included in this evaluation. Clinical trials, retrospective or prospective, were also reviewed, even though they did not always meet the inclusion criteria set forth. This review of the literature shows that, based on the evidence provided by 2 trials, there is a lack of strong evidence of the long-term stability of maxillary expansion in adolescent patients with posterior crossbites at the initiation of orthodontic therapy. Factors responsible for this include high attrition rates, lack of adequate control groups, unclear diagnosis and ill-defined study end points, and lack of standardization of studies. The conclusions that can be drawn from our review are as follows: there is a clear need for well-designed and well-controlled retrospective or prospective clinical trials for the evaluation of stability of maxillary expansions. At the present time, orthodontists must accept that some treatment modalities do not yet have a high level of evidence for treatment effectiveness.

Long-term skeletal and soft-tissue responses after advancement genioplasty

The objectives of this cephalometric study were to assess the skeletal stability of advancement genioplasty 3 years after surgery and to evaluate the predictability of soft-tissue changes. The subjects comprised 21 consecutive patients who had no additional orthognathic surgical procedures. Lateral cephalograms were taken at 5 times: immediately preoperative, immediately postoperative, 6 months postoperative, and 1 and 3 years postoperative. Mean surgical advancement at pogonion was 8.4 mm. Three years after surgery, mean relapse at pogonion was 8% of the surgical advancement. Part of this change was most likely due to bone remodeling. No patient demonstrated a clinically significant postoperative change at pogonion. The soft tissue of the chin was found to follow bony movement in a ratio of 0.9:1. Great individual variability was observed. The mentolabial fold depth increased as a result of the treatment. Effects of advancement genioplasty on the lips were small. A prediction ratio based on long-term skeletal changes is likely to generate an estimate that is more appropriate to present to the patient.

Long-term skeletal changes with rapid maxillary expansion: a systematic review.

The objective was to evaluate long-term transverse, anteroposterior and vertical skeletal changes after rapid maxillary expansion (RME). The data were clinical trials that assessed skeletal changes through cephalometric analysis. No surgical or other simultaneous treatment during the evaluation period was accepted. Electronic databases (PubMed, Medline, Medline In-Process & Other Non-Indexed Citations, Cochrane Database of Systematic Reviews, ASP Journal Club, DARE, CCTR, Embase, Web of Sciences and Lilacs) were searched with the help of a senior Health Sciences librarian. Abstracts that appeared to fulfill the initial selection criteria were selected by consensus. The original articles were then retrieved. A methodological checklist was used to evaluate the quality of the selected articles. Their references were also hand-searched for possible missing articles. Articles without an adequate control group to factor out growth changes were excluded. Only three articles (one measuring transverse and two anteroposterior and vertical changes) measured RME stability after active expansion, all of them had some methodological flaws, which limit the attainable conclusions. An individual analysis of these articles was made. Long-term transverse skeletal maxillary increase is approximately 25% of the total dental expansion for prepubertal adolescents. Better long-term outcomes are expected in transverse changes because of RME in less skeletally mature patients. RME appears not to produce clinically significant anteroposterior or vertical changes in the position of the maxilla and mandible. The conclusions from this systematic review should be considered with caution because only a secondary level of evidence was found. Long-term randomized clinical trials are needed.

Mandibular setback by sagittal split ramus osteotomy: A 12-year follow-up

Short- and long-term skeletal changes after mandibular setback were analyzed using bilateral sagittal split ramus osteotomy. Twelve patients who had undergone mandibular setback surgery between 1986 and 1990 were available for long-term cephalography on average 12 years after primary surgery. The mean amount of surgical setback had been 6.4 mm. After the first postoperative year, there was skeletal relapse of 1 mm at the B-point and pogonion (Pg), amounting to 14% of the initial skeletal setback. In contrast to condylar displacement and proximal segment rotation, osteotomy slippage was associated with positional changes at the B-point and Pg. From 1 to 12 years postoperatively, the B-point and Pg remained stable. Mandibular ramus and corpus length decreased 2.1 mm and 1.3 mm, respectively, indicating remodeling at the osteotomy sites and probably condylar resorption.

Nail Patella Syndrome. A 55-year Follow-Up of the Original Description

The long-term skeletal changes and the lack of significant clinical complaints in a 77-year-old woman with nail patella syndrome are described. Fifty-five years previously she was one of the first reported patients. These early patients came from two families with involvement of multiple individuals with the variable constellation of deformities. We reviewed her skeletal natural history and her family history as it related to nail patella syndrome involvement and treatment, and correlated the original premolecular biology description and subsequent long-term follow-up with the current molecular and genetic concepts of the cause of the variable expression of nail patella syndrome.