Membership of the Joint Dental Faculties (MJDF) Paediatric Dentistry and Orthodontics Syllabus

Which medicament is now most commonly recommended for primary molar pulpotomy, and what historically used agent has been abandoned?

Ferric sulfate or MTA/Biodentine are recommended for vital pulpotomy. Formocresol is being phased out due to concerns over formaldehyde toxicity/carcinogenicity.

What canal-filling material is used in primary tooth pulpectomy and why must it be resorbable?

A resorbable paste such as zinc oxide eugenol, iodoform-based (e.g. Vitapex/Metapex, $\ce{Ca(OH)2}$+iodoform) is used so it resorbs in step with the physiological root resorption, avoiding interference with the succedaneous permanent tooth.

What are the management options for an unrestorable primary tooth?

Extraction (under LA, sedation or GA as appropriate), with consideration of balancing/compensating extractions and space maintenance. The decision weighs the child's cooperation, symptoms, and the position relating to the developing permanent dentition.

Define balancing and compensating extractions.

Balancing extraction: removal of the contralateral tooth in the same arch to prevent a centreline shift. Compensating extraction: removal of the equivalent opposing-arch tooth to prevent over-eruption. Used mainly with primary canines/first molars to maintain symmetry.

State the eruption sequence of the primary dentition.

A (central incisor) ~6 months, B (lateral incisor) ~7–9 months, D (first molar) ~12–18 months, C (canine) ~16–22 months, E (second molar) ~24–33 months. All 20 primary teeth are usually present by ~3 years.

State the typical eruption ages of the first permanent teeth.

First permanent molars and lower central incisors erupt at ~6 years; the dentition continues with incisors (7–8), premolars and canines (~10–12), second molars (~12), and third molars (~18–24).

What is the usual eruption sequence of the permanent teeth in the lower arch?

6 (first molar), 1 (central incisor), 2 (lateral incisor), 3 (canine), 4 (first premolar), 5 (second premolar), 7 (second molar), 8 (third molar) — i.e. 6-1-2-3-4-5-7-8.

Define natal and neonatal teeth.

Natal teeth are present at birth; neonatal teeth erupt within the first 30 days of life. They are most often prematurely erupted primary lower incisors and may be removed if very mobile (aspiration risk) or causing feeding trauma (Riga-Fede).

What is meant by an ectopic eruption, and which permanent teeth are most commonly affected?

Eruption of a tooth in an abnormal position/path. Most commonly the maxillary canine (palatal impaction), maxillary first permanent molar (impacting against the E), and mandibular second premolars/incisors.

What is molar incisor hypomineralisation (MIH)?

A qualitative, systemically-derived enamel defect affecting one or more first permanent molars (often with incisors), presenting as demarcated opacities (white/cream to yellow/brown) of normal thickness enamel that may undergo post-eruptive breakdown.

How does MIH differ from fluorosis and from enamel hypoplasia?

MIH: demarcated, asymmetric opacities on FPMs/incisors (qualitative defect, normal thickness). Fluorosis: diffuse, symmetrical opacities related to excess fluoride. Hypoplasia: a quantitative defect — reduced enamel thickness/pitting/grooves with sharp margins.

Why are MIH-affected molars often difficult to manage clinically?

The porous hypomineralised enamel is prone to rapid post-eruptive breakdown and caries, causes hypersensitivity, and gives poor anaesthesia and poor bonding — leading to repeated restoration failure and pain.

Define hypodontia, oligodontia and anodontia.

Hypodontia: developmental absence of one or more teeth (excluding third molars). Oligodontia: absence of six or more teeth (excluding third molars). Anodontia: complete absence of all teeth.

Which teeth are most commonly congenitally absent in hypodontia (excluding third molars)?

Mandibular second premolars and maxillary lateral incisors are the most commonly missing, followed by maxillary second premolars. Third molars are the most commonly absent teeth overall.

What is a supernumerary tooth and what are the main types?

A tooth additional to the normal complement. Types: conical (peg-shaped, e.g. mesiodens), tuberculate (barrel-shaped, often paired, commonly impede incisor eruption), supplemental (normal morphology, e.g. extra lateral incisor), and odontome.

What is a mesiodens and why is it clinically important?

A mesiodens is a conical supernumerary tooth in the maxillary midline. It can cause failure of eruption, displacement or rotation of permanent central incisors, midline diastema, or cyst formation, so often warrants removal.

What factors determine the prognosis and management decision for a first permanent molar (FPM) of poor prognosis?

Degree of destruction/restorability, presence of symptoms/pulpal involvement, the child's age and dental development (ideally bifurcation of the lower 7 calcifying), presence of the third molar, the existing occlusion and crowding, and orthodontic plans.

What is the ideal dental age for elective extraction of a lower first permanent molar to allow good space closure by the second molar?

Around 8–10 years, when there is radiographic evidence of calcification of the bifurcation of the developing lower second molar (and ideally the presence of the developing third molar).

What is the rationale for compensating extraction of an upper FPM when a lower FPM is extracted?

To prevent over-eruption of the unopposed upper first molar; the upper FPM is more forgiving of timing, but balancing extraction of a sound FPM is generally not routinely indicated.

State Angle's classification of malocclusion based on first permanent molars.

Class I: the mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar. Class II: lower molar distal to this (upper buccal groove relationship anterior). Class III: lower molar mesial to the Class I position.

Describe the British Standards Institute incisor classification of malocclusion.

Class I: lower incisor edges occlude with/below the cingulum plateau of the upper incisors. Class II div 1: lower incisors posterior, upper incisors proclined, increased overjet. Class II div 2: upper incisors retroclined, minimal/normal overjet. Class III: lower incisor edges anterior to the cingulum, reduced/reversed overjet.

Define overjet and overbite.

Overjet: the horizontal distance between the upper and lower incisor edges (normal ~2–4 mm). Overbite: the vertical overlap of the lower incisors by the upper incisors (normal ~ one-third to half the lower incisor crown).

What does the IOTN (Index of Orthodontic Treatment Need) measure, and at what grade is treatment usually warranted?

IOTN has a Dental Health Component (grades 1–5) and an Aesthetic Component (1–10). NHS treatment is generally indicated for DHC grade 4–5, or grade 3 with an aesthetic component of 6 or more.

What anterior finding in a child warrants prompt orthodontic/surgical assessment for possible supernumerary or impaction?

Failure of a permanent incisor to erupt 6 months after its antimere (contralateral tooth), or asymmetry of eruption — warranting radiographs to exclude a supernumerary, ectopic tooth or pathology.

At what age should the position of the maxillary permanent canine be assessed by palpation, and why?

By age 9–10 years the buccal canine bulge should be palpable. Non-palpable canines at 10–11 warrant radiographic assessment because early detection of palatal ectopia allows interceptive extraction of the primary canine.

What is the interceptive measure for a palatally ectopic maxillary canine, and how successful is it?

Extraction of the primary (deciduous) canine at age ~10–13 years can normalise the path of eruption of the permanent canine. It is most successful when the canine is not severely displaced (e.g. its crown is distal to the lateral incisor's long axis).

What is the purpose of a space maintainer, and name common types.

To preserve arch length/space for the erupting permanent successor after premature loss of a primary tooth. Types: band-and-loop, lingual/transpalatal arch, Nance palatal arch, and removable appliances with prosthetic teeth.

What is serial extraction and when is it used?

A planned sequence of extractions (primary canines, then first primary molars, then first premolars) in cases of severe crowding with a Class I relationship, used to guide the permanent incisors and canines into better alignment and relieve crowding.

How is an ectopically erupting first permanent molar impacted against the second primary molar managed?

Mild cases may self-correct (reversible) — monitor. If it persists, interceptive measures include placing a separating elastomeric or brass wire, a distalising appliance, or disking/extraction of the E to allow the FPM to erupt.

What is the significance of a torn maxillary labial frenum in an infant during safeguarding assessment?

In a non-ambulant (pre-walking) infant, a torn upper labial frenum is highly suspicious of inflicted trauma (e.g. forced feeding) and should prompt urgent safeguarding referral, as it is unlikely to occur accidentally in a baby who cannot move independently.