Recent Advances in Dentistry

The biologic process that has an underlying control system at the cellular and tissue levels is called Morphogenesis. Two mechanisms combine to form the skeleton: intramemebranous ossification and endochondral ossification. It is in the latter that the vertebrae and long bones are formed, while intramembranous ossification is responsible for the cranial bones. While somatic and craniofacial development have been shown clearly to be associated, the growth of the craniofacial region – involving, as it does, interaction between growth sites adjacent to each other, each of which has a different pattern and grows at different times and at different rates, is highly complex. The purpose of this chapter with the question-answer format is to provide the basic concepts on craniofacial growth and development.

Orthodontic diagnosis and treatment planning is based on three important components: facial, skeletal and dental diagnoses. In the last years, the impact of facial/dental appearance, the malocclusion, and treatment for these conditions on psychological and functional well-being have drawn increasing attention from clinicians and researchers. Emphasis has been placed on frontal and lateral aesthetics, keeping in mind that facial proportions are more important than absolute numerical values. The most common photo evaluation in orthodontic diagnosis includes the facial frontal, facial profile facial smile, and oblique smile photo. Facial concavity or convexity, lips dimension and position, smile arc, gingival display and over all facial balance should be considered in the overall treatment plan. This chapter, with the question-answer format and clinical examples, describes the surface markings of the face, soft-tissue cephalometric points, facial planes and facial angles.

It is important to understand the aetiology of malocclusion so that orthodontic treatments can focus on the prevention of these conditions. Angle was the first to develop a simple dental relationship assessment based on the sagittal relationship between the upper and lower permanent molars. Since the introduction of cephalometric radiographs, hard tissue evaluation through cephalometric analysis has become an integral part of orthodontic treatment planning because it provides information such as the skeletal size, position, proportion and symmetry of the individual by which it is possible to assess skeletal disharmonies. The diagnosis of skeletal and dental relationships and their contributions to orthodontic treatment will be addressed in this chapter.

The mixed dentition period spans the period where both primary and permanent teeth are present. This period of dental development requires complex coordination between resorption of primary tooth roots, alveolar bone development and eruption of succedaneous permanent teeth. A thorough knowledge of dental arch dimensions changes, as a result of growth and development, is of paramount importance to the clinician. The purpose of this chapter with the question-answer format is to provide in depth the relationship between the tooth eruption pattern and dental arch changes during the transition from mixed to permanent dentition. In the second part of the chapter, through clinical examples and a problem-based approach, a thorough knowledge of the tooth eruption sequence, as well as tooth eruption abnormalities and arch space loss is provided.

Early diagnosis and successful treatment of developing malocclusions can have both short-term and long-term benefits while achieving the goals of occlusal harmony and function and dentofacial aesthetics. Guidance of eruption and the development of permanent dentition is an integral component of comprehensive oral health care for all paediatric orthodontic patients. Such guidance should contribute to the development of a permanent dentition that is in a stable, functional, and aesthetically acceptable occlusion and normal subsequent dentofacial development. The purpose of this chapter with the question-answer format is to provide the principles for proper occlusal guidance, prevention of developing malocclusions and proper interceptive orthodontic treatment during the mixed dentition period. In the second part of the chapter, a series of clinical examples and the paediatric orthodontic intervention treatment are provided.

Posterior crossbite is one of the most prevalent malocclusions in the mixed dentition period; it does not have a spontaneous correction and should be treated as early as possible, after an accurate diagnosis. Maxillary expansion is considered an effective and reliable method for increasing transverse dimension in patients with unilateral or bilateral posterior crossbites. Moreover, it seems that this not only enlarges the constricted maxillae, but also creates additional spaces in the dental arches to resolve borderline dental crowding in some patients. This chapter addresses the aetiology, diagnosis and treatment of maxillary transverse discrepancy in the mixed dentition period.

Dental anomalies can be caused by any etiological factor that interrupts odontogenesis. Leaving environmental factors aside, genetics have been found to be a factor at various levels in dental anomalies and the fact that some human dental anomalies are often seen together supports the evidence that there is shared genetic control of disturbances in dental development. Early diagnosis can be assisted by recognition of dental anomalies (e.g. peg shape lateral incisors) in early mixed dentition that have a genetic association with canine impaction. Early detection of palatal canine displacement will allow clinicians to focus on prevention of canine impaction. The purpose of this chapter is to approach the early diagnosis and appropriate orthodontic intervention of dental anomalies and tooth impaction.

Class II malocclusion is a much more frequent type of skeleton-dental disharmony than a class III malocclusion. The nature of these malocclusions is not a result of a single component, but a variety of different dental and skeletal combinations such as maxillary-mandibular skeletal and dental position, as well as the vertical components. The more severe the malocclusion at the young ages, the greater the psychosocial and functional problems present. The disharmony could become more pronounced during the pubertal peak period and continue until growth is completed. As a result, it is important to understand the aetiology of these malocclusions so that orthodontic treatments can focus on possible prevention or early intervention in order to avoid any related craniofacial deformities. The timing of treatment varies from early intervention during the pre-pubertal stages of growth or intervention during the peakgrowth stage after the patient has completed their active growth.