All of the following can contribute to the development of malocclusion EXCEPT:

Correct answer: B. Internal root resorption

• A. Heredity is a major determinant of malocclusion, governing jaw size and relationship, tooth size, and characteristic patterns such as the mandibular prognathism that runs in families.
• B. CORRECT as the EXCEPTION. Internal resorption is a process occurring WITHIN the root canal system, driven by odontoclastic activity on the internal dentine surface following pulpal inflammation. It is confined to the interior of the tooth and does not alter the tooth's position in the arch, its eruption path, or the relationship between the jaws. It threatens the tooth's survival, not the occlusion.
• C. Hormonal disturbances alter craniofacial growth substantially — acromegaly produces mandibular overgrowth with a class III relationship and spacing, while hypothyroidism delays eruption and exfoliation.
• D. Premature loss of primary teeth allows adjacent teeth to drift into the space, producing arch length loss, crowding and impaction of the permanent successor. This is one of the commonest LOCAL causes of malocclusion, and it is why space maintainers exist.

Note: Categorise causes as general (heredity, endocrine, nutritional, congenital, habits) versus local (premature loss, retained primary teeth, supernumeraries, ankylosis, abnormal frenal attachment, dental anomalies). Internal resorption sits in neither list — it is a pulpal disease.