Tarek El-Bialy, Donna Galante, Sam Daher
Anterior open bite can be of dental, skeletal, functional or a combination of all three in origin. An anterior open bite is present when there is no contact between the upper and lower anterior teeth and no overbite (vertical overlap of the upper and lower incisors). The severity of open bite varies from an edge to edge relationship to a severe open bite with teeth contact only in the molar areas. Ideally, treatment of open bites should be started as early as they are diagnosed by the dentist or pediatric dentist/orthodontist. Often, early intervention can eliminate the causes of the open bite especially if they are related to a persistent habit such as thumb sucking or mouth breathing. Also, early intervention can re-direct jaw growth and establish a more favorable mandibular growth direction. This chapter will discuss treatment of open bite in non-growing patients by using clear aligner therapy and no adjunct orthognathic surgery.
* Corresponding author Tarek El-Bialy: Faculty of Medicine and Dentistry 7-020D Katz Group Centre for Pharmacy and Health Research University of Alberta, Edmonton, Alberta T6G 2E, Canada; E-mail: email@example.com.
Digit sucking is a common cause of anterior open bite. The incidence of digit sucking is around 30% at age 1 and decreases to 2% by age 12 . Open bites that exist in the primary dentition usually will resolve on their own once the child ceases the digit habit. Anterior open bites that extend into the mixed and permanent dentition may require orthodontic or even surgical intervention. A vertical component to growth may occur during this time frame as the child persists with a digit habit, lip or tongue habits, airway obstruction and genetic skeletal growth abnormalities. Complex orthodontic treatment involving the use of molar intrusion with or without temporary anchorage devices may be required.
Pretreatment clinical records A) photographs showing class III right side and anterior open bite/edge-to edge relationship. B) Initial Cephalometric and panoramic radiographs
Orthognathic surgery is often the last resort in treating these type of cases . Fixed appliance therapy has been the standard of care in orthodontics in correcting anterior open bites. Unfortunately, research has shown that relapse is frequent with about 40 to 80% relapse [3–5]. Persistent anterior tongue position is often cited as one of the most important factors in relapse. Great success has been demonstrated by Dr. Robert Boyd, Chairman of the Department of Orthodontics at the University of Pacific Dental School, with use of clear aligners to treat anterior open bites . This case study will show how clear aligners can predictability close anterior open bite.
A 16 year old female presented to our office with her mother with the chief compliant of a bite problem and not being able to chew properly. Medical history was non-contributory. Her dental history included a previous phase of treatment in the mixed dentition for “several years” while living in Asia. Mom stated that her bite was perfect at the end of that treatment and all her teeth were in place when the braces were removed. Since moving back to the United States, she has grown a few more inches and her bite changed. The patient was not interested in braces or treatment at all, but was more inclined to proceed with Invisalign than fixed appliances. Initial records (Fig. 9.1) show that the patient has a mesiocephalic face (concave profile and prognathic chin projection) with a midline deviation to the left of approximately 3mm. She has an edge to edge anterior open bite and presents with a Class III molar relationship on the left side. Cephalometric analysis shows a significant class III skeletal pattern, high mandibular plane angle and bimaxillary protrusion of both upper and lower incisors.
A non-extraction approach was presented to the patient and parent. Treatment objectives were to correct the edge-to edge open bite, reduce the bimaxillary protrusion, provide overjet and overbite and align the midlines.