Bohn’s Nodules: Definition, Epidemiology, Developmental Sites, Pathophysiology, and Clinical Characteristics

They are smooth white or yellowish prominences or cysts that can appear in the mouth of newborns.

These nodules are located at the junction of the hard and soft palate, and along the lingual and buccal parts of the dental ridges, away from the midline.

These nodules are 1 to 3 mm in size and contain keratin content.

The nodules are the result of cystic degeneration of the epithelial remnants of the dental lamina (Serres remnants). Bohn’s nodules are non-malignant cysts that can disappear in the first three months of life.

Bohn’s nodules differ from Epstein’s pearls by the site where they develop.

Bohn’s nodules, described by Heinrich Bohn in 1886 as “cysts of the mucous glands,” are distributed over the junction of the hard and soft palate.

They are derived from minor salivary glands. They are found at the junction of the hard and soft palate, and along the lingual and buccal parts of the dental ridges, away from the midline. These nodules are 1 to 3 mm in size and are filled with keratin.

Bohn also classified the cysts in the alveolar ridges as mucous gland cysts. However, a century later these cysts were shown to be microkeratocysts.

Terminology

  • Cysts that originate in the palatal glands, scattered in the hard and soft palate.
  • It is now used interchangeably for palatal and gingival cysts of newborns.

Odontogenic cysts arise from the epithelial components of the odontogenic apparatus or its remnants, which are trapped within bone or peripheral gingival tissues.

With regard to their pathogenesis, some of them are considered “developmental” and others as “inflammatory.”

Many features of the baby’s mouth are unique and peculiar to the birth period of development, and some benign oral mucosal conditions are frequently found in newborns, which are transient in nature.

The frequency of inclusion cysts is high in newborns, but they are rarely seen after 3 months of age.

Conditions classified from m2 that affect newborns are:

  • Epstein’s pearls.
  • Bohn’s nodules.
  • Cysts of the dental lamina.

Depending on the histological origin and location in the oral cavity, they can be classified as:

  • Epstein pearls.
  • Bohn’s nodules.
  • Gingival cysts.

Gingival cysts of newborns usually present in multiples, but occasionally they also present as solitary nodules. They are found on the alveolar ridges of newborns or young babies.

Fragments of dental lamina that remain within the mucosa of the alveolar ridge after tooth formation are believed to proliferate to form these small keratinized cysts. In general, they are asymptomatic and do not cause any discomfort for the baby.

Depending on the location, these cysts can be divided into:

  • Paladins cysts.
  • Alveolar cysts.

Those found in the median-palatal raphe are called palatal cysts, while those found in the buccal, lingual, or alveolar crest are alveolar (or gingival) cysts. The reported prevalence of alveolar cysts in newborns ranges from 25% to 53%, while for palatal cysts it is around 65%.

Individually, the prevalence of gingival cysts in infants is 13.8%, Epstein’s pearl is 35.2%, and Bohn’s nodules are 47.4%.

Without sexual predilection. Although the prevalence is high, these cysts are rarely seen by the cyst or pediatrician due to the transient nature of these cysts, which disappear within 2 weeks to 5 months of postnatal life.

The cyst is lined by an odontogenic epithelium that is covered by a thick layer of keratin, which gives the cyst its yellow color. Most of these cysts rupture on their own, a few days after birth, exuding keratin.

In some cases, however, they can remain for a period of several months and in such cases surgical opening is indicated.

epidemiology

Gingival cysts of the newborn appear after the fourth month in the uterus, during dental development.

Common, some estimate that at least 50% of newborns have gingival cysts that resolve spontaneously

Development sites

They occur along the alveolar ridge, while palatal cysts appear along the midline of the posterior hard palate or the anterior soft palate.

Pathophysiology

They arise from epithelial remnants of the dental lamina that sprout deeply after the fourth month in the uterus and are present at birth

Clinical features

  • Multiple (usually less than six), sessile yellowish-white to pearl-like papules, 1 – 4 mm.
  • Superficial (break easily).

Treatment

None; spontaneous rupture with cyst lining incorporated into the oral mucosa.