Non-syndromic Concomitant Hypo-Hyperodontia in the Anterior Region of MandibleAn Extremely Rare Phenomenon: Literature Review with Recent Updates

Abstract

Introduction: Hypo hyperdontia is a numeric mixed anomaly in which teeth may be supernumerary or absent, relative to the normal complement. The occurrence of this condition in the same individual is termed “Concomitant Hypo-Hyperdontia” (CHH). The presence of CHH in the same dental arch is uncommon, especially when it occurs in the front of the mandible in a Nonsyndromic Concomitant Hypo-Hyperdontia (NCHH). Aim: To conduct a literature review of the published articles in the English language, regarding NCHH in the anterior region of the mandible covering the period from October 1977 to December 2021. Materials and Methods: An extensive electronic search was conducted in February 2022, from Google Scholar, PubMed, and Elton B. Stephens Company (EBSCO) databases, using keywords such as mandible, hypodontia, hyperdontia and nonsyndromic. Manual sorting of the preselected literature, revealed only 19 published papers concerning NCHH in the frontal region of the mandible, spanning a period of 44 years. Results: The review analysed the data from 19 published studies, which presented 24 affected patients with a mean age of 12.36 years, with a male/female ratio of 1:1, involving a total of 41 missing teeth, including bilateral mandibular central incisors at 66.66%, followed by missing unilateral central incisor at 29.16% and 1 case (4.16%) displaying absence of both lateral incisors. Regarding 25 presented supernumerary teeth (ST), 72% of cases presented single midline ST, 20% were single unilateral ST, and one case presented double ST (8%) located bilaterally. The majority of ST (84%) were erupted conical-shaped. Conclusion: The study confirmed the exceptionally rare occurrence of NCHH in the anterior region of the mandible. Due to its interference with esthetics and function, the clinician should possess sufficient knowledge regarding NCHH diagnosis and management.