++
For children under age 3, a knee-to-knee position allows the provider to complete the oral examination in a safe and comfortable way (Figure 17–1). The parent is instructed to sit facing the provider with the knees of both the parent and provider touching or interlocking to create a table. The infant is then positioned on the parent’s lap facing the parent, with each leg wrapped around the parent’s waist. The child’s head is lowered onto a pillow on the provider’s lap for the examination, with the parent being instructed to stabilize the child’s arms and legs with their hands and elbows, respectively. Crying during the examination is a normal response in healthy children and will allow for better visualization of the oral cavity. For older, more cooperative children, the oral examination can be performed on the dental chair. With the chair reclined and the patient in a supine position, a pillow can be added for support for the legs depending on the size of the patient.
++
++
During the examination, the clinician assesses the extra-oral tissues, intra-oral hard and soft tissues, and overall oral hygiene maintenance.
+++
Extra-Oral Examination
++
Extra-oral examination includes assessing the overall symmetry of the face. This can easily be done by holding a piece of floss across the patient’s facial midline. Evaluation of the face can be done by dividing the face in equal thirds. The facial upper third extends from the hair line to the glabella, the middle third spans from the glabella to the base of the nose (subnasale), and the lower third extends from subnasale to the chin. The length of each facial thirds is usually equal or similar. Extraoral findings such as muscle strain over the chin can also point to a skeletal or orthodontic problem. The submandibular glands and lymph nodes should be palpated to identify any enlargement or pain. A temperomandibular joint (TMJ) examination should determine the range of motion and any deviation while opening or closing the jaw. The preauricular area is palpated to determine the presence of any TMJ crepitations or clicking indicative of underlying joint pathology.
+++
Intra-Oral Soft Tissue Examination
++
The mouth of the normal newborn is lined with an intact, smooth, moist, shiny mucosa (Figure 17–2). The alveolar ridges are continuous and relatively smooth. Within the alveolar bone are numerous tooth buds, which at birth are mostly primary teeth. The sagittal and vertical maxillo-mandibular relationships are different at birth, with an anterior open bite being considered physiologic before the onset of tooth eruption. The mouth is more triangularly shaped and the oral cavity is small and filled by the tongue due to a small and slightly retrognathic lower jaw. This pseudo micrognathia is due to ventral positioning of the fetus to facilitate its passage through the birth canal and will generally correct after birth.
++
++
Small maxillary and mandibular frena can be found in the anterior midline region (Figure 17–3), and small accessory frena are often present posteriorly. A more prominent midline maxillary labial frenum, which is observed in 25% of children, tends to diminish in size and recede apically with normal development and the eruption of teeth.
++
++
The tongue is connected to the floor of the mouth by the lingual frenum (Figures 17–4 and 17–5), whereas the upper lip is connected to gingiva above the upper central incisors by the maxillary frenum. With ankyloglossia, the attachment is tight, closer to the tip of the tongue or high up on the alveolar ridge (see Figure 17–5) and may restrict movement. Ankyloglossia typically does not inhibit normal growth and development; however, it can cause feeding problems, such as difficulty latching or pain during nursing. These concerns can be addressed with frenotomy of the lingual frenum shortly after birth. In most cases breastfeeding will be improved. In contrast, frenotomy of the maxillary frenum is rarely indicated as there is no evidence that this reduces breastfeeding difficulties.
++
++
+++
Soft Tissue Variations
++
The most common soft tissue pathology in newborns are neonatal cysts, including Bohn’s nodules, Epstein pearls, and dental lamina cysts. Bohn’s nodules are remnants of mucous gland tissue that occur on the buccal and lingual aspects of the alveolar ridges. Epstein pearls are remnants of epithelial tissue trapped at the time of palatal fusion during early fetal development and are found along the mid-palatal raphe. Dental lamina cysts are remnants of the dental lamina and are typically located on the alveolar mucosa. These cysts are 1–3 mm round, smooth, nontender white, gray, or yellow nodules that are self-limiting in nature and typically resolve by 3 months of age.
+++
Intra-Oral Hard Tissue
++
The development of alveolar bone is evident with development of tooth buds and later eruption of the primary teeth and permanent teeth. Alveolar bone encases the developing tooth buds and supports the teeth through periodontal ligament attachments. Alveolar ridges are usually horseshoe-shaped at birth and the mandibular and maxillary alveolar ridges contact each other at their most posterior aspects at birth. With eruption of teeth during further development, these ridges will no longer contact each other.
++
Hard tissue formation of the primary teeth begins at approximately 14 weeks in utero, with all 20 primary teeth being calcified to varying degrees, with traces of the enamel of first permanent molars being present at birth. Primary teeth generally begin to erupt around 7 months of age but may appear as early as 3–4 months or as late as 12–16 months of age. A complete set of primary teeth (20 teeth) is usually erupted between 30 and 36 months. Although there are variations, usually anterior teeth erupt before posterior teeth, and mandibular teeth before their maxillary counterparts.
++
Between 6 and 7 years of age, the first permanent molars erupt distal to the existing primary second molars. This phase of development, when both primary and permanent teeth simultaneously exist, is known as the mixed dentition. Following eruption of the first permanent molars, mandibular permanent central incisors erupt, replacing existing primary central incisors and resulting in the exfoliation of the first primary tooth. Children continue to exfoliate primary teeth as their permanent successors erupt until approximately the age of 12, with the maxillary canines typically being the final primary tooth to be shed. Around the same time, the second permanent molars erupt, followed later in adolescence by the development of the permanent third molars, colloquially referred to as wisdom teeth. Once the patient has erupted a complete set of permanent teeth (with the exception of third molars), they are considered to have adolescent dentition.
+++
Tooth Numbering Systems
++
Tooth numbering systems enable clinicians to more effectively communicate unequivocally about a patient’s teeth. In the United States, the Universal Numbering System (Figure 17–6) is used, which assigns the uppercase letters A–T for primary teeth and the numbers 1–32 for permanent teeth. The initial designation begins on the upper right, most posterior tooth and continues along the upper teeth to the left side. The count then drops to the lower, most posterior tooth on the left side and continues along the bottom teeth to end on the lower right side.
++
+++
Hard Tissue Variations
++
Potential variations in dental hard tissues involve the number and size of primary and permanent teeth. When an extra tooth or teeth are present they are referred to as supernumerary tooth/teeth and the condition is known as hyperdontia. If a supernumerary tooth occurs in the maxillary incisor midline area it is referred to as mesiodentes. The removal of such a tooth is recommended especially if it hinders eruption of the adjacent permanent incisors.
++
Tooth agenesis is rare in the primary dentition but occurs with an incidence of 5% in the permanent dentition. Depending on the number of teeth that are congenitally missing, the condition is referred to as either hypodontia (less than six absent teeth) or oligodontia (more than six absent teeth). The most frequently missing permanent teeth are the third molars, followed by the mandibular second premolars and maxillary lateral incisors. Tooth agenesis is caused by several independent defective genes, which can act alone or in combination with other genes. It can occur as an isolated problem but is common with cleft lip/cleft palate or as part of the phenotype of over 200 syndromes, including ectodermal dyplasias.
++
Minor variations in the size of teeth are common. Macrodontia refers to teeth that are abnormally large and microdontia is the term given to teeth that are smaller than the usually expected size. Apart from the number and shape of the teeth, there may also be abnormalities in the overall formation of the hard tissue structures such as enamel and dentin (amelogenesis imperfecta or dentinogenesis imperfecta, respectively).
++
Many symptoms are ascribed to the process of tooth eruption or teething. However, any temporal association with fever, upper respiratory infection, or systemic illness is coincidental rather than related to the eruption process. Attributing fever to teething without a thorough diagnostic evaluation for other sources has resulted in missing serious organic disease.
++
Common therapies for teething pain include the application of over the counter teething gels or liquids. For teething children, their main ingredient, benzocaine, can rarely cause methemoglobinemia. While “natural” benzocaine-free formulations are available, systemic analgesics such as acetaminophen or ibuprofen are safer and more effective. Chewing on a teething object can be beneficial, if only for distraction purposes.
++
Occasionally, swelling of the alveolar mucosa overlying an erupting tooth can be seen. This usually asymptomatic condition appears as localized red to purple, round, raised, and smooth lesion. Treatment is rarely needed as these eruption cysts/hematomas resolve with tooth eruption.
+++
Pathologies of Tooth Eruption
++
On rare occasions (1:3000), natal teeth are present at birth and neonatal teeth erupt into the oral cavity within the first month of life. These are most commonly (85%) primary mandibular incisors. A radiograph should be taken to determine whether they are regular or supernumerary teeth (10%). Although the preferred approach is to leave the tooth in place, natal teeth that are supernumerary, hypermobile, or of inferior structural quality should be extracted. Other indications for removal of natal teeth include nursing difficulties and when their sharp incisal edges cause laceration of the ventral surface of the infant’s tongue (Riga-Fede disease).
++
Premature loss of a primary tooth can either delay or accelerate eruption of the underlying permanent tooth. Accelerated eruption occurs when the primary tooth is removed within 6–9 months of its normal exfoliation, but loss of the primary tooth more than 1 year before its expected exfoliation typically delays eruption of its successor. The loss of a primary tooth often causes adjacent teeth to tip or drift into the resulting space, leading to space loss for the underlying permanent tooth. Placement of a space maintainer can prevent such space loss.
++
Other local factors delaying or preventing tooth eruption include supernumerary teeth, cysts, odontogenic tumors, over-retained or ankylosed primary teeth, and impacted teeth. A generalized delay in eruption may be associated with global developmental delays, endocrinopathies, and other systemic conditions.
++
Insufficient space in the dental arch may cause permanent teeth to erupt ectopically and cause a usually painless root resorption of the adjacent primary tooth. This phenomenon is observed most commonly with the maxillary first permanent molars.
++
Occasionally, mandibular incisors erupt lingually and lead to over-retention of the primary predecessor, resulting in a “double row of teeth.” If the primary tooth is still firmly in place, the dentist should remove it to allow its successor to drift into proper position.
++
Impaction occurs when a permanent tooth is prevented from erupting. Although crowding is a frequent reason, over-retained primary or supernumerary teeth are other causes. The teeth most often affected in the developing dentition are the maxillary incisors and canines. Often, they are brought into correct alignment by early extraction of the preceding or adjacent primary teeth. If this approach is ineffective, surgical exposure of the impacted tooth and orthodontic treatment are indicated.
+
Casamassimo
PS, Fields
HW, McTigue
DJ, Nowak
AJ: Pediatric Dentistry: Infancy Through Adolescence. 5th ed. St. Louis, MO: Mosby Elsevier.
+
Dean
JA, Avery
DR, McDonald
RE: McDonald and Avery’s Dentistry for the Child and Adolescent. 9th ed. Maryland Heights, MO: Mosby Elsevier.