Understanding Causes and Treatment Options
Gummy smiles, characterized by an excessive display of gum tissue when smiling, are a common concern among dental patients. Affecting between 10% to 33% of the population, this condition can present in various forms and have multiple causes and treatment options.
In this blog, we will explore the causes and diagnostic methods for gummy smiles. Part 2 (coming soon) will discuss comprehensive treatment options, including orthodontic and ortho-restorative solutions.
What Does a Gummy Smile Look Like?
A gummy smile is typically defined as an excessive gingival display of more than 2mm when smiling. It can be classified into three categories based on severity:
Mild: 2-4mm of gingival display
Moderate: 4-8mm of gingival display
Severe: More than 8mm of gingival display
Most patients (88%) exhibit both anterior and posterior excess, though it can be isolated to one area.
Diagnosing a Gummy Smile
Assessing a gummy smile can be challenging because it involves understanding both static and dynamic aspects of the smile.
There are two types of smiles to consider:
Full Smile (Posed Smile): Involves the contraction of the levator muscles, raising the upper lip to the nasolabial fold.
Maximum Smile (Spontaneous Smile): Involves further raising of the upper lip by the levator labii superior muscles, with flaring nostrils and squinting eyes.
The full smile is generally considered more reliable for assessment, with video analysis being the most accurate method as it is really hard to capture the smile in a static photo.
Measuring a Gummy Smile
To formally assess a gummy smile, measure the vertical distance from the zenith of the maxillary dentition to the lower border of the upper lip during a full smile. Repeating the measurement ensures consistency, though it doesn't reveal the aetiology or appropriate treatment. A comprehensive evaluation includes examining soft tissue, dental, and skeletal causes. Digital smile design tools can make the measurements a lot easier as it is done on a calibrated photo or screenshot of a video.
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Aetiology of Gummy Smiles
Soft Tissue Assessment
Soft tissue assessment involves two key aspects: static measurements and dynamic mobility.
Static Measurements: Measure the upper lip length from the subnasale to the inferior border of the upper lip. Average lengths are 23mm for males and 21mm for females. Evaluate the crown width-to-length ratio (80%) and check for altered passive eruption using periodontal probing.
Dynamic Mobility: Assess the upper lip's mobility by measuring the distance between the upper lip in a full smile and at rest, then dividing by the upper lip length at rest. The average mobility ratio is 27%.
Dental Assessment
Excessive eruption of maxillary anterior teeth, also known as passive dental eruption, can cause a gummy smile. This can result from a lack of an occlusal stop due to antero-posterior or vertical plane discrepancies. Bimaxillary proclination can also cause the upper lip to retract, leading to a gummy smile.
Skeletal Assessment
Skeletal causes involve the position of the maxilla.
Two methods for assessment are:
Linear Measurement: Measure the vertical height from the maxillary plane to the incisal tip, with an average of 29.7mm and a threshold for vertical maxillary excess at 32.0mm.
Angular Measurement: Use the maxillary height angle to assess the inferior positioning of the maxilla. The greater the angle, the more inferior the maxilla is relative to the cranial base.
However, the skeletal relationship is often multifactorial, making it the least robust assessment method. Unexplained increases in gingival display might indicate vertical maxillary excess.
Treatment Options for Gummy Smiles
Orthodontic Solutions
Clear aligners, such as Invisalign, ClearCorrect, SureSmile, Spark or Angel Aligners, offer a modern solution for treating gummy smiles, especially when the cause is moderate dental or related to moderate soft tissue issues. It is worth noting that correcting passive dental eruption intruding the anterior teeth and adjusting the occlusal plane is less predictable with clear aligners compared to fixed braces.
Ortho-Restorative Solutions
It is not always possible to achieve the desired aesthetic result with orthodontics alone. In these instances a combination of orthodontics, surgery and restorative solutions have to be considered.
Conclusion
Gummy smiles are a complex and multifaceted condition requiring a structured diagnostic approach. By understanding the causes and available treatments, including orthodontic and ortho-restorative options, you can achieve a balanced and beautiful smile. Stay tuned for Part 2, where we will delve into these treatment options in more detail.
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Sincerely
Dentist, co-founder & business advisor
Jesper Hatt DDS
Phone: +41 78 268 0078
AlignerService helps dentists create realistic, safe and predictable treatment plans with clear aligners.
Currently, we help1500 dental practices in 19 different countries. AlignerService is a preferred partner of ClearCorrect.
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