Osteogenesis in an in vitro coculture of human periodontal ligament fibroblasts and human microvascular endothelial cells.

BACKGROUND: Periodontal bone healing is a complex process involving many cells and processes that must function flawlessly for proper healing to occur. The exact progenitor cells that contribute to this process are not fully characterized. Periodontal fibroblasts and pericytes were postulated to be potential osteoprogenitor cells. This study describes a viable coculture model for the in vitro study of osteogenesis. METHODS: Human microvascular endothelial cells (HMVEC) and human periodontal ligament (HPDL) fibroblasts were cocultured in a layered model and monitored for the development of runt-related transcription factor 2 (runx2) and desmin expression by real-time polymerase chain reaction. Conditions shown to be osteogenic (bone morphogenetic protein [BMP]-2 and enamel matrix derivative [EMD]) were compared to a control coculture that was unstimulated. RESULTS: The HMVEC migrated into a layer of collagen containing only HPDL cells as monitored by fluorescent labeling. runx2 and desmin expressions were increased in stimulated cocultures in week 2 compared to controls. At week 3, the unstimulated control cocultures developed the expression of runx2 and desmin, and the cocultures that were stimulated with EMD and BMP-2 achieved significantly higher levels of these factors than any of the other conditions. CONCLUSIONS: Signs of osteogenesis were present in the cocultures in unstimulated and stimulated conditions. However, in the stimulated condition, osteogenic markers were increased at earlier time points. As such, this model may provide a good method for the study of specific cellular processes that may lead to osteogenesis and eventually for understanding the regeneration of periodontal bone in vivo.

Relationship of body mass index to stability of mandibular advancement surgery with rigid fixation.

INTRODUCTION: Obesity is a growing problem in the United States. We examined patients undergoing orthognathic surgical correction for Class II skeletal malocclusions and assessed outcomes in relation to body mass index. METHODS: The patients (n = 78) were divided into 3 groups (obese, overweight, and normal or thin) based on body mass index score. They were treated with mandibular advancement (mean, 4.9 mm) with rigid fixation and evaluated cephalometrically for postsurgical changes over a 2-year period; a subset of 54 patients was followed for 5 years. RESULTS: Obese and overweight patients experienced relative postsurgical forward movements at B-point (means, 2.6 and 1.0 mm, respectively), whereas the normal or thin patients had relapses (mean, -0.7 mm) over the 2 years. This trend held up at 5 years, with the obese patients experiencing 3 mm of forward movement compared with the normal or thin patients. Potential reasons for this difference in postsurgical response are orthopedic effects of tongue posture and hormonal and biochemical differences caused by obesity. CONCLUSIONS: Obese and overweight patients have different responses to mandibular advancement with rigid fixation compared with normal or thin patients. These data should enable orthodontists and surgeons to more appropriately treat obese patients.

A review of the effects of expansion of the nasal base on nasal airflow and resistance.

PURPOSE: The purpose of this article is to inform the reader of the current literature regarding nasal airflow resistance. The anatomy and physiology of nasal airflow resistance will be examined and the known effects of widening of the nasal airway upon airflow will be described. MATERIALS AND METHODS: This article is a review of the current literature regarding nasal airflow and resistance and the effects of widening of the nasal base. No patient data were collected. RESULTS: The literature shows that nasal airflow resistance can be changed by surgical manipulation and by rapid palatal expansion, but that the effects on airflow resistance and future growth and development are unpredictable. CONCLUSION: Patients with a maxilla that is constricted in the transverse dimension and nasal airflow problems may benefit from expansion of the nasal base. The resultant effects upon nasal airflow resistance and subsequent growth and development are unpredictable and therefore airflow issues alone may not be a primary reason to increase the transverse dimension of the nasal base.

Obesity in adolescence: implications in orthodontic treatment.

The incidence of obesity is increasing in the United States and around the world, and it is likely that obese patients will present for orthodontic therapy in greater numbers in the future. The implications of obesity for psychosocial well-being, bone metabolism, craniofacial growth, and pubertal growth must be assessed in treating obese orthodontic patients. This review article focuses on the relevant issues concerning obesity in regard to orthodontic therapy.

Psychiatry in orthodontics. Part 1: Typical adolescent psychiatric disorders and their relevance to orthodontic practice.

Adolescence is a time of rapid physical and mental development. It is also a time when many diagnosable psychiatric diseases are first noticed. A prior study showed that a high rate of suicidal behavior is seen in orthodontic practices. The orthodontist is in a unique position among medical practitioners because treatment occurs over several years with frequent appointments. This article is a current review of the etiology, diagnosis, and therapy for several pertinent mental disorders that occur in adolescents, including mood disorders, schizophrenia, attention-deficit hyperactivity disorder, personality disorders, and eating disorders. All have been associated with high rates of suicidal behavior and completed suicides. With a keen eye for the development of psychiatric issues, the orthodontist is in a position to make appropriate referrals, if needed.

Psychiatry in orthodontics. Part 2: Substance abuse among adolescents and its relevance to orthodontic practice.

Substance abuse by adolescents is a serious problem that will touch every orthodontic practice. Recent data show that 40% of tenth graders in the United States will use an illicit drug at some time, and 18% will do so in a 30-day period. These are significant figures that should impact orthodontic diagnosis and treatment planning. The nature of orthodontic treatment is unique in that the orthodontist will see relatively healthy adolescent patients on a monthly basis over a period of years. The orthodontist is in a prime position to recognize potential substance abuse problems and make referrals. This article discusses various types of substance abuse, diagnosis, options for referral, and orthodontic implications.