Richard Jacobson

Airway Growth and Development: A Computerized 3-Dimensional Analysis

PURPOSE The present study was undertaken to investigate the changes in the normal upper airway during growth and development using 3-dimensional computer analysis from cone-beam computed tomography (CBCT) data to provide a normative reference. METHODS The airway size and respiratory mode are known to have a relationship to facial morphology and the development of a malocclusion. The use of CBCT, 3-dimensional imaging, and automated computer analysis in treatment planning allows the upper airway to be precisely evaluated. In the present study, we evaluated the growth of the airway using 3-dimensional analysis and CBCT data from age 6 through old age, in 1300 normal individuals. RESULTS The airway size and length increase until age 20 at which time a variable period of stability occurs. Next, the airway at first decreases slowly in size and then, after age 40, more rapidly. Normative data are provided in the present study for age groups from 6 to 60 years in relation to the airway total volume, smallest cross-sectional area and vertical length of the airway. CONCLUSIONS This 3-dimensional data of the upper airway will provide a normative reference as an aid in the early understanding of respiration and dentofacial anatomy, which will help in early treatment planning.

Maxillary, Mandibular, and Chin Advancement: Treatment Planning Based on Airway Anatomy in Obstructive Sleep Apnea

Surgical correction of obstructive sleep apnea (OSA) syndrome involves understanding a number of parameters, of which the 3-dimensional airway anatomy is important. Visualization of the upper airway based on cone beam computed tomography scans and automated computer analysis is an aid in understanding normal and abnormal airway conditions and their response to surgery. The goal of surgical treatment of OSA syndrome is to enlarge the velo-oropharyngeal airway by anterior/lateral displacement of the soft tissues and musculature by maxillary, mandibular, and possibly, genioglossus advancement. Knowledge of the specific airway obstruction and characteristics based on 3-dimensional studies permits a directed surgical treatment plan that can successfully address the area or areas of airway obstruction. The end occlusal result can be improved when orthodontic treatment is combined with the surgical plan. The individual with OSA, though, is more complicated than the usual orthognathic patient, and both the medical condition and treatment length need to be judiciously managed when OSA and associated conditions are present. The perioperative management of the patient with OSA is more complex and the margin for error is reduced, and this needs to be taken into consideration and the care altered as indicated.

Three-Dimensional Imaging and Computer Simulation For Office-Based Surgery

PURPOSE Advancements in computers and imaging, especially over the last 10 years, have permitted the adoption of 3-dimensional imaging protocols in the health care field. In addition, the affordability and ease of use of these modalities allow their widespread adoption and use in diagnosis and treatment planning. This is particularly important when the deformities are complex involving both function and esthetics, such as those in the dentofacial area and with orthognathic surgery. MATERIALS AND METHODS Image fusion involves combining images from different imaging modalities to create a virtual record of an individual called a patient-specific anatomic reconstruction (PSAR). We describe the system and show its use in 1 case. RESULTS Image fusion and, more specifically, PSAR permit a more accurate analysis of deformity as an aid to diagnosis and treatment planning. CONCLUSION Three-dimensional imaging and computer simulation can be effectively used for planning office-based procedures. The PSAR can be used to perform virtual surgery and establish a definitive and objective treatment plan for correction of a facial deformity. The end result is improved patient care and decreased expense.

3-Dimensional Facial Simulation in Orthognathic Surgery: Is It Accurate?

PURPOSE The purpose of this study was to measure the accuracy of 3D computer simulation of soft tissue changes after orthognathic surgery. MATERIALS AND METHODS Consecutive patients who underwent orthognathic surgery were studied by photogrammetric facial scanning and cone-beam computed tomography before and after surgery. The photogrammetric scan was then fused to the cone-beam computed tomogram, creating a patient-specific image. The surgery was simulated in 3D form and the simulated soft tissue face was compared with the actual facial scan obtained 6 months postoperatively. Absolute millimeter differences between the simulated and actual postoperative changes in selected cephalometric skin markings were computed. RESULTS The study was composed of 23 subjects (mean age, 31 yr; 13 women and 10 men). Eighteen different cephalometric landmarks were measured (total, 28). For 15 landmarks, the difference between actual and simulated measurements was smaller than 0.5 mm. Only 3 landmarks had a difference of 0.5 mm, and these were in the region of the labial landmarks. CONCLUSION Based on the present study, 3-dimensional computer surgical simulation of the soft tissue of the face for routine orthognathic surgery is accurate enough for routine clinical use.

Treating obstructive sleep apnea: The case for surgery

Obstructive sleep apnea (OSA) is a chronic, progressive, and potentially life-threatening disorder that can be effectively treated with surgery. It is also a condition that orthodontists see in their offices every day; thus, they are ideally suited to diagnose and treat it. OSA is related to an anatomic obstruction of the upper airway; surgical correction of the obstruction is effective and definitive, and should be considered for appropriate patients with mild, moderate, or severe OSA. OSA is a multifactorial condition, and diagnosis and treatment must be individualized, with multidisciplinary management. The definitive diagnosis and treatment plan is formulated after a comprehensive medical and dental history and examination. Adjunctive diagnostic studies such as cone-beam computerized tomographic imaging for airway analysis, fiber-optic nasopharyngoscopy, polysomnography, and 3-dimensional cephalometrics are included in the workup. OSAoccursduringsleepasaresultofanobstruction or partial collapse of the upper airway. Signs and symptoms include tiredness or sleepiness during the day, memory loss, irritability, depression, decreased libido, and headache. If OSA is not treated, it can cause diabetes, hypertension, heart disease, and sudden death while asleep. 1 Exacerbating factors include a high body mass index (.34). 2 Continuous positive airway pressure (CPAP) is currently considered the gold standard for the treatment of OSA. 3,4 Positive airway pressure can be divided into continuous (CPAP), bilevel, and auto titrating modes, through a nasal, oral, or oronasal interface during sleep. Unfortunately, compliance with CPAP is variable for numerous reasons including social stigma, feelings of claustrophobia, and complaints of inability to sleep peacefully. 5 Side effects include nasal congestion, thickening of the soft tissues with prolonged use, skin ulceration, and eye irritation. 6 CPAP failure because of poor compliance has been reported to be as high as 25% to 50%. 7,8 OSA is most severe during deeper sleep; thus, patients using CPAP for less the 4 hours a night still suffer from the consequences of OSA.