BDS 7129: Eruption PDF

BDS 7129: Eruption Aim: The aim of this lecture is to describe tooth eruption times, and the sequence, of the primary and permanent teeth Subject Title Goes Here Objectives: • Understand the definition of eruption • Recognize eruption times of the primary and permanent teeth • Understand that the...

BDS 7129: Eruption Aim: The aim of this lecture is to describe tooth eruption times, and the sequence, of the primary and permanent teeth Subject Title Goes Here Objectives: • Understand the definition of eruption • Recognize eruption times of the primary and permanent teeth • Understand that the sequence of eruption is more important than eruption age • Recognize the difference in chronology between Egyptian and international populations • Eruption signs and symptoms and how to deal with it • Identify abnormalities and factors that can affect eruption Definition of Eruption The movement of a tooth from its site of development within the jaws to its position of function within the oral cavity, this process continues till the tooth meets its opposing (Massler and Schour, 1941) • In the case of the permanent dentition the primary tooth roots must also be removed. Phases of Eruption Pre-eruptive End of early bell phase Beginning of root formation Eruptive Onset of root formation phase the oral cavity Post-eruptive Reaching the occlusal plane phase tooth Appearance of tooth in Life span of the Eruption Theories Several theories explained the eruption process However, NO single structure or theory was found to be responsible for eruption For eruption to take place there has to be a pathway through the bone and force must be generated to propel the tooth through the bone and gingival tissue to its new position. Eruption Theories: • The method by which the force is created is open to debate. • Some have suggested cellular proliferation at the apex of the tooth; alternatively, a localized change in blood pressure has been implicated. • It has also been suggested that the force of eruption causes resorption of bone in the tooth’s path, although this has also been questioned. Animal experiments have shown that the resorption process can be uncoupled from the eruption process, i.e. it is not necessary for the tooth to erupt to cause resorption of bone. • The follicle has been shown to play an essential role in active tooth eruption, but it is not fully understood how the coronal part of the follicle is activated to initiate osteoclastic activity in the alveolar bone ahead of the tooth and clear a path for tooth eruption. • What causes the tooth to erupt through the opening in the crypt created by the resorption process is also open to question. Suggested theories including root elongation, periodontal ligament, and local changes in vascular pressure have been discounted as major factors, and although bone growth at the base of the crypt is essential for eruption it is possible that this is simply reactive to tooth movement. • It is fair to say that this source of eruption remains elusive. Eruption Theories: 1) Bone remodeling 2) Dental follicle (helps with bone remodeling) 3) Root elongation (may affect speed of eruption) 4) Growth and traction forces of periodontal ligaments (direction and the increased presence of fibroblasts, affected eruption) 5) Vascular pressure/blood vessel thrust or hydrostatic pressure theory A local increase in tissue fluid pressure in the periapical region is sufficient to move the tooth 6) Hormonal influence (thyroid hormone, parathyroid Hormone, Growth Hormone) 7) Growth of Dentin Tooth development : • Teeth start to form during week 5 of embryonic life, and the process of tooth formation continues until the roots of the third permanent molars are completed at about 20 years of age. • The stages of tooth formation are the same whether the tooth is of the primary or the permanent dentition, although obviously the teeth develop at different times. Chronology: Data on the chronology of tooth development are usually given as mean values from series of observations. Intrauterine: Beginning of formation of primary teeth 5-8 w.i.u Calcification of 1ry central incisor starts at 13-16 w.i.u The mineralization of the primary teeth starts during 14–18 weeks in utero. Chronology: At Birth Primary teeth: Central Incisors: Calcification 5/6 of the crowns Lateral incisors: Calcification 2/3 of the crowns Canine: Calcification of the incisal tip 1st and 2nd molars: Calcification of cusps Permanent 1st molars: calcification of cusp tips may be evident Chronology: • The root formation of the primary teeth is completed between 1.5 and 3 years. The • • crowns are halfway mineralized at birth and become fully formed during the first year of life. Mineralization of the permanent teeth starts at birth with the first molars. The incisors and canines start their mineralization during the first year of life, the premolars and second molars between the second and third years of life, and the third molar between the eighth and eleventh years of life. However, the normal range is wide. • The crowns of the permanent teeth (except third molars) are generally completed between 5 and 7 years of age. Root development takes about 6–7 years. In general, the mandibular teeth develop earlier than the maxillary teeth. A marked sex difference has been observed in tooth formation, girls being on average half a year ahead of boys. Chronology: • Variations in eruption dates have been seen among children Gender, ethnicity, socioeconomic factors have been associated with these variations (Suri et al., 2004) A variation of 6 months on either sides is considered Normal in primary dentition. Max, maxilla; Mand, mandible. Adapted from Oral Structural Biology: Embryology, Structure, and Function of Normal Hard and Soft Tissues of the Oral Cavity and Temporomandibular Joints, Schroeder, H.E., Copyright (1991) with permission from Georg Thieme Verlag, Thieme Medical Publishers, Inc. Ctd In :Welbury R et al; Paediatric Dentistry; 5th Edition, Oxford Press Eruption of primary teeth (in months) A B C D 7-8 8-9 18 14 E D 20 12 C B E 24 A 16 7-8 6-7 Kronfeld R: Bur 35:18–25, 1935 (based on research by WHG Logan and R Kronfeld); adapted by Kronfeld R, Schour I: J Am Dent Assoc 26: 18-32, 1939; further adapted by McCall JO, Wald SS: Clinical dental roentgenology: technic and interpretation including roentgen studies of the child and young adult, Philadelphia, 1940, WB Saunders Sequence Of Eruption Of Primary Dentition • While the eruption sequence—the order in which the teeth erupt—is B C D E usually as described in this section, A there is considerable variation in 7-8 8-9 18 14 24 the actual age at which the teeth erupt. • In any event, there is an almost A B C D E continuous process of tooth eruption between the ages of 7 6-7 7-8 16 12 20 and 29 months. Eruption times in months Milestones For primary teeth: Tooth Eruption (primary) 1 yr for incisors + 1.5 yr for canine & molars Root Completion (primary) + 1.5-2.5 yr Root Shedding 3-6 yrs Starting of Completion 3 yr primary + Root + of tooth Resorption (Eruption of Permanent permanent) Mechanism of shedding of primary teeth • Prior to shedding of primary incisors, canines and molars, the roots of the primary teeth are resorbed and their crowns shed. • Dentinoclasts appear on the apical surface of the roots of the primary teeth, possibly initiated by the pressure created by the dental sac of the erupting permanent teeth. • However, even if a permanent tooth is missing, the primary predecessor usually undergoes root resorption, although commonly at a much slower pace. The role of pulpal dentinoclasts in this process is still being investigated. Eruption of Permanent teeth: (in years) 1 2 3 4 5 6 7 7-8 8-9 11-12 10-11 10-12 6-7 12-13 7 6 5 4 3 2 1 11-13 6-7 11-12 10-12 9-10 7-8 6-7 Kronfeld R: Bur 35:18–25, 1935 (based on research by WHG Logan and R Kronfeld); adapted by Kronfeld R, Schour I: J Am Dent Assoc 26: 18-32, 1939; further adapted by McCall JO, Wald SS: Clinical dental roentgenology: technic and interpretation including roentgen studies of the child and young adult, Philadelphia, 1940, WB Saunders Sequence of Eruption of Permanent Dentition • The primary dentition erupts more or less continuously over a two-year period. However, the permanent dentition erupts in two stages: first, the incisor teeth and the first permanent molars erupt, and then the other teeth in the buccal segments. • The lower central incisor and the first permanent molars erupt at about the age of 6 years. • The upper central incisor and the lower lateral incisor erupt at about the age of 7 years and the upper lateral incisor at about the age of 8 years. • As with the primary teeth, while some variation in the timing of tooth eruption is only to be expected, this eruption sequence should not vary. Sequence of Eruption of Permanent Dentition • The lower canine and the first premolar teeth are the next to erupt at about 10 years of age, followed by the upper canine and the second premolar teeth at about the age of 11 and the second molar teeth at about the age of 12. • Third molar teeth start to erupt from about the age of 16 onwards, but the eruption of third molars is very variable; not uncommonly, these teeth are impacted against their neighbors and fail to erupt at all. Sequence of Eruption: • The eruption sequence—the order in which the teeth erupt—is more important than the age at which the teeth erupt. Therefore if there is a local problem with regard to the establishment of a normal occlusion, it is likely to become apparent in the first instance as a disturbance of the eruption sequence. • While some variation in the timing of tooth eruption is only to be expected, the eruption sequence should NOT vary This sequence is considered favourable for maintaining the length of the arches during the transitional dentition Why the sequence of eruption is more important than eruption age: Permanent Teeth: Undesirable sequences that may cause discrepancy in arch length: • Eruption of Maxillary lateral incisors before central incisors • If the upper lateral incisor erupts before the upper central incisor, almost certainly there is something impeding the eruption of the central incisor, for example a supernumerary tooth or a dilaceration of the root of the central incisor. • Mandibular 1st and 2nd premolars erupt before the canine lingual tipping of the incisors and increased overbite Why the sequence of eruption is more important than eruption age: Undesirable sequences that may cause discrepancy in arch length: • Mandibular/Maxillary 2nd permanent molar develops and erupts before the 2nd premolar mesial migration/tipping of the first permanent molar and encroachment on the space needed for the second premolar Chronology: Egyptian population (primary teeth) Tooth Age Upper Jaw Lower Jaw Boys (months) Girls (months) Boys (months) Girls (months) Central Incisor 14.5 14.8 13.5 15.5 Lateral incisor 16 18.2 16.8 18.3 Canine 23 24.4 23.1 20.6 1st molar 20.6 19.4 20 21.3 2nd molar 28.1 25.1 27.5 28.2 (Ezz et al., 2016) Chronology: Egyptian population (permanent teeth) Tooth Age Upper Jaw Lower Jaw Boys (yrs) Girls (yrs) Boys (yrs) Girls (yrs) Central Incisor 7.7 7.7 6.9 6.8 Lateral incisor 8.5 8.2 7.5 7.6 Canine 10.8 10.7 9.9 9.7 1st premolar 10 10 9.8 9.7 2nd premolar 10.3 10.4 10.5 10.5 1st molar 7 6.8 6.7 6.9 2nd molar 11.2 11.1 11.3 11.2 (Ezz et al., 2016) Chronology: According to AAPD Teething signs and symptoms: • • • • • • • • • Increased salivation (drooling) Rash and red face Gum rubbing Increased finger sucking Red gingiva with a little tearing Bleeding gums Inflammation Usually painful and tender gingiva Itchiness Other systemic manifestations: • Low-grade fever • Decreased appetite for solid foods • Watery eyes • Disruption of eating and sleeping patterns • Irritability • Loose stools However, no strong evidence of relation Management: Gently brush the erupting tooth - Chilled teething toys (rings) to chew on, sugar-free chilled food - Keep child well hydrated - First dental visit should occur within 6 months of eruption Or at the age of 12 months Management: Analgesics may be prescribed to manage pain Teething gels are NOT recommended to prevent toxicity. Teething gels Seek medical advice to rule out systemic conditions Disorders of Eruption: • Eruption of teeth is not always correlated with somatic development. • Children with growth disturbances may exhibit delayed eruption or the delay may be due to other causes such as gingival overgrowth due to medication as phenytoin. • More importantly premature exfoliation of teeth is invariably associated with severe systemic disease and require investigation. • Delayed eruption of primary dentition requires no treatment other than determining that the teeth are present. • Parents should be reassured that there is extreme variability in eruption of teeth, plus or minus 6 months for primary teeth, plus or minus 1 year for permanent teeth. Disorders of Eruption: • In the permanent dentition, delayed eruption should be investigated for the presence of supernumeraries and other pathology. • While the actual timing of tooth eruption is variable, tooth crown and root development and the eruption sequence are of much more relevance. • The failure of eruption of a contralateral tooth more than 6 months after appearance of its partner requires investigation. Eruption associated problems local 1- Eruption hematoma (cyst) 2- Eruption sequestrum 3- Epstein pearls ,Bohn Nodules & dental lamina cyst 4- Premature eruption (natal & Neonatal teeth) 5- Ankylosed teeth 6- Ectopic eruption 7- Premature loss of primary teeth 8- Supernumerary teeth, mesiodens, odontomes 9-Sequalae to trauma 10- Cysts Eruption associated problems local: • Eruption hematoma (cyst) - A soft tissue cyst resulting from a separation of the dental follicle from the crown of an erupting tooth with fluid accumulation - Lesions color range from normal to blue-black or brown, that maybe filled with blood due to trauma - No treatment is necessary as it usually ruptures spontaneously If lesion becomes infected, the roof of the cyst may be opened surgically Eruption associated problems local • Eruption sequestrum - Usually related to the first permanent molars - A small bony deposit related to the occlusal surface of the tooth - As the tooth erupts the sequestrum usually falls Eruption associated problems local • Epstein pearls ,Bohn Nodules ,and dental lamina cyst - Small white lesions that may be present on the mucosa in different locations in the mouth, mistaken for erupting teeth: Epstein pearls: along midpalatine raphae Bohn nodules: buccal and lingual aspects of the dental ridge Dental lamina cysts: crest of the ridge Eruption associated problems local • Natal and Neonatal teeth - Natal teeth: teeth present at birth Neonatal teeth: erupt during the first 30 days of life - incidence varies from 1:1,000 to 1:30,000. - Usually mandibular primary incisors (85%) - Only a few are supernumerary teeth. In most cases, anterior natal and neonatal teeth are early eruption of normal primary incisor tooth. • Management: - Preserved unless excessively mobile or causing feeding problems Eruption associated problems local • Ectopic eruption A change in the path of eruption, that may be due to arch inadequacy, a supernumerary tooth or an ankylosed tooth. Management would depend on the cause • Lingual eruption of Permanent incisors: Sometimes the permanent lower incisors would erupt while the primary incisors are still in place Normal: lingual forces of the tongue/ growth of the alveolar bone leads to the normal positioning Requiring no extraction, unless no self-correction seems to be undergoing. Eruption associated problems local • Ankylosed teeth - “Solid fixation of a tooth resulting from fusion of the cementum and alveolar bone, with obliteration of the periodontal ligament. It is uncommon in the deciduous dentition and very rare in permanent teeth”. (Jablonski's Dictionary of Dentistry, 1992) - In the normal process of shedding, intermittent resorption of primary teeth followed by a rest or a reparative phase, an excessive reparative phase may lead to the ankylosis of the tooth Eruption associated problems local • Ankylosed teeth Clinically: - Appear submerged or in infra-occlusion - Dull, solid sound on tapping Radiographically: - Seems as interruption of the periodontal space - Primary mandibular molars shows the highest chances of ankylosis - Ankylosis of primary anterior teeth is usually the result of a trauma Eruption associated problems local • Supernumerary teeth, mesiodentes, and odontomas Supernumerary teeth, mesiodentes, and odontomas constitute major reasons for disturbances in tooth eruption. Can also be associated with systemic syndromes NOT all supernumerary teeth, mesiodentes or odontomas will have an influence on eruption. Only if the follicle surrounding the tooth element is located in the eruption pathway will impaction (follicle collision) occur Eruption associated problems local • Supernumerary teeth, mesiodentes, and odontomas Management: Early diagnosis based on clinical and radiographic examinations is important to decide on the treatment and when it should be performed with an optimal result. In most cases the treatment involves surgical removal of the supernumerary teeth, mesiodentes, and odontomas Eruption associated problems local • Cysts The most common cysts causing tooth eruption problems are dentigerous (follicular) cysts. These cysts originate from the dental follicle of nonerupted teeth. The cysts can reach substantial size and thereby inhibit eruption of the involved tooth but can also displace surrounding tooth germs Eruption associated factors Systemic 1. Down’s syndrome 2. Cleidocranial dysplasia 3. Hypothyroidism 4. Hypopituitarism 5. Achondroplasia • Other factors: • Bisphosphonates medications • Chemotherapy/Radiotherapy related to head and neck region References • American Association of Paediatric Dentistry. Dental Growth and Development, 2003. Accessed Online[June 2018] available at: http://www.aapd.org/media/Policies_Guidelines/R_DentalGrowth.pdf • American Association of Paediatric Dentistry. Guideline on Infant Oral Health Care, 2014. Accessed Online[June 2018] available at: http://www.aapd.org/media/policies_guidelines/g_infantoralhealthcare.pdf • American Association of Paediatric Dentistry. Management of the Developing Dentition and Occlusion in Pediatric Dentistry, 2014. Accessed Online[June 2018] available at: http://www.aapd.org/media/Policies_Guidelines/BP_DevelopDentition.pdf • Hatibovic-Kofman, S. and Ari, T., 2013. Managing discomfort caused by teething. Journal (Canadian Dental Association), 79, p.d14 • Koch G., Kreiborg S. and Andreasen J (2017). Eruption and Shedding of Teeth. In Pediatric Dentistry A clinical approach (third edition). Wiley Blackwell (pp 40-55) • Marks, S.C. and Odgren, P.R., 2002. Structure and development of the skeleton. In Principles of Bone Biology (Second Edition) (pp. 315). • Massler, M. and I. Schour: Studies in tooth development: theories of eruption. Am. J. Orthodont. Oral Surg. 27:552-578 (1941) • McDonald, R.E., Avery, D.R. and Dean, J.A., 2011. Eruption of the teeth: local, systemic, and congenital factors that influence the process. In McDonald and Avery Dentistry for the Child and Adolescent (Ninth Edition) (pp. 150-176). • Parekh, S., Harley, K. and Bloch-Zupan A., 2018. Anomalies of tooth formation and eruption. Paediatric Dentistry (5th edition) (pp.257276) • Rabea, A. 2018. Recent advances in understanding theories of eruption (evidence based review article). Future Dental Journal. • Sirnath SK et al., 2013. Mechanism of tooth eruption & its clinical significance - A systematic review of literature. Elixir Dentistry 65 • Suri, L., Gagari, E. and Vastardis, H., 2004. Delayed tooth eruption: pathogenesis, diagnosis, and treatment. A literature review. American Journal of Orthodontics and Dentofacial Orthopedics, 126(4), pp.432-445. • Reading material: • Students are advised to review any relevant teaching provided in the first year. In addition they are advised to read relevant sections of the following texts: • Koch G et al; Pediatric Dentistry - a Clinical Approach; 3rd Edition, Wiley Blackwell • Welbury R et al; Paediatric Dentistry; 5th Edition, Oxford Press • AAPD, Dental growth and development, http://www.aapd.org/media/Policies_Guidelines/RS_DENTGrowthandDev. pdf Aim: The aim of this lecture is to describe tooth eruption times, and the sequence, of the primary and permanent teeth Subject Title Goes Here Objectives: • Understand the definition of eruption • Recognize eruption times of the primary and permanent teeth • Understand that the sequence of eruption is more important than eruption age • Recognize the difference in chronology between Egyptian and international populations • Eruption signs and symptoms and how to deal with it • Identify abnormalities and factors that can affect eruption Subject Title Goes Here