Related Experiment Video
Updated: Jun 17, 2026
07:26
Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Dental abnormalities associated with X-linked hypohidrotic ectodermal dysplasia in dogs
J R Lewis1, A M Reiter, E A Mauldin
1Department of Clinical Studies, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania, Philadelphia, PA 19104-6010, USA. jrlewis@vet.upenn.edu
Orthodontics & Craniofacial Research
|January 19, 2010
Summary
X-linked hypohidrotic ectodermal dysplasia (XLHED) causes severe dental abnormalities in dogs, including missing teeth and malocclusion. Canine XLHED closely resembles human disease, making dogs a valuable model for studying this genetic disorder.
Area of Science:
- Veterinary Genetics
- Comparative Pathology
- Oral Biology
Background:
- X-linked hypohidrotic ectodermal dysplasia (XLHED) affects multiple species, with well-documented orofacial and dental issues in humans and mice.
- Limited documentation exists regarding dental abnormalities in dogs with XLHED.
Purpose of the Study:
- To describe the clinical and radiographic findings of dental abnormalities in dogs with XLHED.
- To compare canine XLHED dental manifestations with those observed in humans.
- To validate dogs as an animal model for human XLHED research.
Main Methods:
- Clinical and radiographic oral examinations were conducted on 17 dogs with XLHED, 3 normal dogs, and 2 heterozygous dogs.
- Evaluated prevalence and severity of orofacial and dental abnormalities using sedated examinations, photographs, and intraoral radiographs.
Main Results:
- Dogs with XLHED exhibited common crown and root abnormalities: hypodontia, oligodontia, conical crowns, reduced cusps/roots, and dilacerated roots.
- Persistent deciduous teeth and malocclusion (Angle Class I and III) were frequently observed in affected dogs.
- Fifteen of 17 affected dogs had Angle Class I malocclusion with canine tooth mesioversion.
Conclusions:
- Dental abnormalities in canine XLHED are prevalent and severe.
- Canine XLHED dental features align with brachyodont tooth type and diphyodont dentition.
- Dogs serve as an orthologous model for studying human X-linked hypohidrotic ectodermal dysplasia.
Related Concept Videos
01:35Pedigree Analysis
Overview
01:15Teeth
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
01:19X-linked Traits
In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.
01:24Renal Tubule and Collecting Duct
The renal tubule is divided into three parts: the proximal convoluted tubule (PCT), the Loop of Henle (LOH), and the distal convoluted tubule (DCT).
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
01:43Sex-linked Disorders
Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
01:33Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...