Effect of mandibular distraction osteogenesis on the temporomandibular joint: a systematic review of animal experimental studies

Long-term follow-up of corrective jaw surgery including distraction osteogenesis in 32 patients with juvenile idiopathic arthritis

Dentofacial deformity following juvenile idiopathic arthritis (JIA) with temporomandibular joint (TMJ) involvement is associated with functional, aesthetic, and psychosocial impairment. Corrective surgical treatment includes combinations of orthognathic surgeries (OS). The aims of this study were to assess orofacial symptoms, functional and aesthetic status, and stability after OS including mandibular distraction osteogenesis (MDO). A prospective study was conducted of 32 patients with JIA of the TMJ and dentofacial deformities who underwent MDO as the only surgery or in combination with bilateral sagittal split osteotomy, Le Fort I, and/or genioplastybetween 2003 and 2018. Data from clinical examinations and cephalograms performed pre- and postoperative and at long-term (mean 4 years) were analysed. Patients experienced unchanged orofacial symptoms (all P > 0.05), short-term TMJ functional impairment (all P < 0.001), and long-term morphological improvements in SNB angle (P < 0.001), anterior facial height (P < 0.001), mandibular length (P = 0.049), overjet (P < 0.001 and P = 0.005), and posterior facial symmetry (P = 0.046). MDO as the only surgery or with secondary adjunctive OS improved dentofacial morphology in terms of mandibular advancement, anterior facial height, posterior facial symmetry, and incisal relationships without long-term deterioration in TMJ function or orofacial symptoms.

Management of temporomandibular joint arthritis in children and adolescents: An introduction for orthodontists

Juvenile idiopathic arthritis (JIA) is the most common inflammatory rheumatic disease of childhood. JIA can affect any joint and the temporomandibular joint (TMJ) is one of the joints most frequently involved. TMJ arthritis impacts mandibular growth and development and can result in skeletal deformity (convex profile and facial asymmetry), and malocclusion. Furthermore, when TMJs are affected, patients may present with pain at joint and masticatory muscles and dysfunction with crepitus and limited jaw movement. This review aims to describe the role of orthodontists in the management of patients with JIA and TMJ involvement. This article is an overview of evidence for the diagnosis and treatment of patients with JIA and TMJ involvement. Screening for the orofacial manifestation of JIA is important for orthodontists to identify TMJ involvement and related dentofacial deformity. The treatment protocol of JIA with TMJ involvement requires an interdisciplinary collaboration including orthopaedic/orthodontic treatment and surgical interventions for the management of growth disturbances. Orthodontists are also involved in the management of orofacial signs and symptoms; behavioural therapy, physiotherapy and occlusal splints are the suggested treatments. Patients with TMJ arthritis require specific expertise from an interdisciplinary team with members knowledgeable in JIA care. Since disorders of mandibular growth often appear during childhood, the orthodontist could be the first clinician to see the patient and can play a crucial role in the diagnosis and management of JIA patients with TMJ involvement.

Distraction osteogenesis promotes temporomandibular joint self-remodeling in the treatment of mandibular deviation caused by condylar ankylosis

Craniofacial deformity and malocclusion are primary concerns following temporomandibular joint ankylosis (TMJa) in growing patients, and they pose even greater challenges in adult patients. The treatment objectives always involve restoring proper jawbone structure, achieving stable occlusion, and attaining satisfactory joint mobility. This report presents a 4-year follow-up of an adult patient with TMJa-induced mandibular deviation, who underwent a combined treatment approach involving distraction osteogenesis (DO) and orthodontic-orthognathic surgery. Orthodontic treatment resulted in favorable occlusion and improved facial esthetics. A new condyle with a reconstructed glenoid fossa in a forward position was established after mandibular DO and the damaged TMJ experienced self-remodeling owing to functional improvement. Thus, this case demonstrates the efficacy of DO in promoting adaptive TMJ self-remodeling with long-term stability when treating mandibular deviation caused by condylar ankylosis in adult patients.

Efficacy and safety of "Yahom" as a traditional Thai herbal therapy: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Yahom is a traditional Thai medicine used to treat syncope and abdominal discomfort.

AIM OF THE STUDY

This study aimed to systematically review all available evidence which purports to support these claims.

MATERIAL AND METHODS

The systematic review accorded with the Cochrane Collaboration framework and PRISMA reporting. Databases including MEDLINE, Excerpta Medica Database (EMBASE), Cochrane library database, and Google Scholar were searched by keywords, Yahom and Ya-hom. Pharmacological and toxicity data from non-animal and animal studies were included.

RESULTS

Twenty-four articles: 2 on in vitro cell lines or bacteria, 3 in vitro cell-free, 5 in vitro animal, 13 in vivo and 1 human mainly reported (A) Cardiovascular effects (i) transient hypotension (0.2-0.8g/kg, intravenous injection (i.v.)), increased cerebral blood flow (2g/kg, single oral) and vascular dilatation/relaxation (ii) elevated blood pressure (BP) (0.2-0.8g/kg, i.v. or 2-4g/kg oral) and vasocontraction. Single Yahom doses (3g) given to healthy volunteers had no effect on cutaneous blood flow, ECG or systolic BP although marginally increased diastolic BP was claimed. (B) Yahom (2-4g/kg) completely inhibited gastric acid secretion evoked by gastric secretagogues. (C) Toxicity: Chronic oral doses of selected Yahoms to rodents (0.001-1g/kg) supports its status as generally regarded as safe.

CONCLUSIONS

Most studies supported declared objectives relating to perceived Yahom actions, but lacked background demonstrating clinical efficacy, and mechanistic data that would validate conclusions. Our study suggests that research into traditional medicinal herbs needs underpinning by appropriate clinical interventions and pharmacovigilance, thereby optimising efficacy and minimizing toxicity by combining traditional wisdom and modern testing.

Effect of unilateral mandibular distraction osteogenesis on mandibular morphology in rabbits with antigen-induced temporomandibular joint arthritis

Aim was to evaluate effect of unilateral distraction osteogenesis (DO) on mandibular morphology in rabbits with antigen-induced arthritis in the temporomandibular joint (TMJ). Forty 8-week-old rabbits were divided into four groups. In groups A,C, arthritis was induced in the right TMJ. Groups A,B underwent DO. Group D served as control group. Cephalometric analysis of mandibular angle, mandibular ramus height, mandibular collum height, and total posterior mandibular height was done on CT-scans preoperatively (T0), after distraction (T1), and at euthanasia (T2). Two-factor ANOVA evaluated the effect of DO and antigen-induced arthritis. No effect of DO or arthritis was observed on mandibular angle or mandibular collum height. For T0-T1, DO increased mandibular ramus height 12.3% (95% CI 5.2-19.4%) in group B (P=0.001) and total posterior mandibular height 6.2% (95% CI 0.3-12.1%) in group A (P=0.04) and 10.0% (95% CI 4.3-15.7%) in group B (P=0.001). For T1-T2, no significant changes occurred in arthritic rabbits (group A). In conclusion, DO increased total posterior mandibular height in rabbits with arthritis. Postoperatively, no significant effect of DO was observed in rabbits with arthritis. Mandibular DO could be a viable treatment modality in patients with TMJ-arthritis.