Shovel-shaped incisors

Shovel-shaped incisors (or, more simply, shovel incisors) are incisors whose lingual surfaces are scooped as a consequence of lingual marginal ridges, crown curvature or basal tubercles, either alone or in combination.

Shovel incisors are relatively more common in East Asian populations, particularly among certain Japanese and Native American populations. The trait is rare or not present in European and African populations.^[1] In some instances, incisors can present a more pronounced version of this called double shovel-shaped. The differences observed in tooth morphology is believed to be partly determined by genetics.^[2] When present, shovel-shaped incisors can indicate correlation among populations and are considered to be one of the non-metric traits in osteology. The characteristic could also be attributed to hormones, duration of development, and the capacity of the maxillary dental arch.

The shovel-shaped dental characteristic can also be traced back to Homo erectus and in Neanderthals.^[1] The morphology of Neanderthal's anterior teeth has been seen as an adaptation to the heavy use of their canines and incisors in processing and chewing food, and the use of their teeth for activities other than feeding.^[3]

References

1 2 Kimura, Ryosuke; Yamaguchi, Tetsutaro; Takeda, Mayako; Kondo, Osamu; Toma, Takashi; Haneji, Kuniaki; Hanihara, Tsunehiko; Matsukusa, Hirotaka; Kawamura, Shoji (2009-10-09). "A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors". American Journal of Human Genetics. 85 (4): 528–535. doi:10.1016/j.ajhg.2009.09.006. ISSN 0002-9297. PMC 2756549. PMID 19804850.
↑ Hemphill, Brian E. (2002-10-01). "Review". Journal of Anthropological Research. 58 (3): 412–414. JSTOR 3631186.
↑ Clement, Anna F.; Hillson, Simon W.; Aiello, Leslie C. (2012-01-01). "Tooth wear, Neanderthal facial morphology and the anterior dental loading hypothesis". Journal of Human Evolution. 62 (3): 367–376. doi:10.1016/j.jhevol.2011.11.014.

Oral and maxillofacial pathology (K00–K06, K11–K14, 520–525, 527–529)

Lips

Cheilitis Actinic Angular Plasma cell Cleft lip Congenital lip pit Eclabium Herpes labialis Macrocheilia Microcheilia Nasolabial cyst Sun poisoning Trumpeter's wart

Tongue

Ankyloglossia Black hairy tongue Caviar tongue Crenated tongue Cunnilingus tongue Fissured tongue Foliate papillitis Glossitis Geographic tongue Median rhomboid glossitis Transient lingual papillitis Glossoptosis Hypoglossia Lingual thyroid Macroglossia Microglossia Rhabdomyoma

Palate

Bednar's aphthae Cleft palate High-arched palate Palatal cysts of the newborn Inflammatory papillary hyperplasia Stomatitis nicotina Torus palatinus

Oral mucosa - Lining of mouth

Teeth (pulp, dentin, enamel)

Periodontium (gingiva, periodontal ligament, cementum, alveolus) - Gums and tooth-supporting structures

Periapaical, mandibular and maxillary hard tissues - Bones of jaws

Temporomandibular joints, muscles of mastication and malocclusions - Jaw joints, chewing muscles and bite abnormalities

Bruxism Condylar resorption Mandibular dislocation Malocclusion Crossbite Open bite Overbite Overjet Prognathia Retrognathia Temporomandibular joint dysfunction

Salivary glands

Orofacial soft tissues - Soft tissues around the mouth

Actinomycosis Angioedema Basal cell carcinoma Cutaneous sinus of dental origin Cystic hygroma Gnathophyma Ludwig's angina Macrostomia Melkersson–Rosenthal syndrome Microstomia Noma Oral Crohn's disease Orofacial granulomatosis Perioral dermatitis Pyostomatitis vegetans

Other

Eagle syndrome Hemifacial hypertrophy Facial hemiatrophy Oral manifestations of systemic disease

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